阅读说明：本技术 使用具有动态控制和优化的列表解码的高效极性码检测 (Efficient polar code detection using list decoding with dynamic control and optimization ) 是由 J·M·林 S·马利克 于 2019-08-22 设计创作，主要内容包括：描述了用于无线通信的方法、系统和设备。无线设备(诸如用户设备(UE))可以监测对码字的解码候选,其中,码字与接收比特度量集合相对应,并且解码候选与使用极性码进行编码的多个信息比特相对应；针对解码候选来确定码字的复合检测度量,其中,复合检测度量是根据极性码的中间极化层的比特度量子集推导出的；以及至少部分地基于复合检测度量来确定用于根据解码候选对码字执行列表解码过程的分类。(Methods, systems, and devices for wireless communication are described. A wireless device, such as a User Equipment (UE), may monitor decoding candidates for a codeword, where the codeword corresponds to a received bit metric set and the decoding candidates correspond to a plurality of information bits encoded using a polar code; determining a composite detection metric for the codeword for the decoding candidates, wherein the composite detection metric is derived from a subset of bit metrics of an intermediate polarization layer of the polar code; and determining a classification for performing a list decoding process on the codeword according to the decoding candidates based at least in part on the composite detection metric.)

1. A method for wireless communication, comprising:

monitoring decoding candidates for a codeword, wherein the codeword corresponds to a received bit metric set and the decoding candidates correspond to a plurality of information bits encoded using a polar code;

determining a composite detection metric for the codeword for the decoding candidate, wherein the composite detection metric is derived from a first subset of bit metrics of an intermediate polarization layer of the polar code; and

determining a classification for performing a list decoding process on the codeword according to the decoding candidates based at least in part on the composite detection metric.

2. The method of claim 1, wherein the determining the classification for performing the list decoding process comprises:

determining to suppress the list decoding process for the decoding candidate.

3. The method of claim 1, wherein the determining the classification for performing the list decoding process comprises:

determining a ranking for performing the list decoding process on the codeword according to the decoding candidates relative to other decoding candidates of a plurality of decoding candidates for a codeword search space.

4. The method of claim 1, wherein determining the composite detection metric comprises:

applying a weighting vector to the first subset of bit metrics.

5. The method of claim 4, wherein determining the composite detection metric comprises:

applying a second weighting vector to a second subset of bit metrics associated with a second intermediate polarization layer of the polar code; and

one or more activation functions are applied to combine the weighted first subset of bit metrics and the weighted second subset of bit metrics.

6. The method of claim 1, wherein determining the composite detection metric comprises:

applying one or more weighting vectors to the first subset of bit metrics to obtain one or more intermediate composite metrics; and

applying one or more activation functions to combine the one or more intermediate metrics to obtain the composite detection metric.

7. The method of claim 1, wherein determining the composite detection metric comprises:

determining a derived bit metric based at least in part on the first bit metric subset and a weighting pattern determined based at least in part on a number of information bits in a subset of leaf nodes corresponding to the first bit metric subset.

8. The method of claim 7, wherein determining the composite detection metric comprises:

applying one or more activation functions to combine the derived bit metrics to obtain the composite detection metric.

9. The method of claim 1, wherein the first subset of bit metrics is determined based at least in part on a single parity operation or a repetition operation from bit metrics at a polarization layer feeding the intermediate polarization layer.

10. The method of claim 1, wherein the determining the classification for performing the list decoding process comprises:

comparing the composite detection metric to a threshold, wherein the threshold is based at least in part on a connection state, a signal metric, a device state, a detection history, a communication protocol, or a combination thereof.

11. The method of claim 1, wherein the first subset of bit metrics corresponds to log-likelihood ratios (LLRs) of a corresponding subset of bit channels of the polar code.

12. A method for wireless communication, comprising:

receiving a search space comprising a plurality of decoding candidates associated with a polar code;

determining a pattern of polarity detection for the search space, the polarity detection being based at least in part on a composite detection metric of the plurality of decoding candidates, wherein the composite detection metric is derived from respective subsets of bit metrics of the plurality of decoding candidates for at least one intermediate polarization layer of the polar code; and

performing a list decoding process for at least one of the plurality of decoding candidates for the search space based at least in part on the pattern of polarity detection for the search space.

13. The method of claim 12, wherein:

the determining the pattern for polarity detection comprises: selecting a prioritization mode for the polarity detection; and

the performing the list decoding process comprises: performing the list decoding process on the plurality of decoding candidates in an order determined based at least in part on the polarity detection.

14. The method of claim 12, wherein:

the determining the pattern for polarity detection comprises: selecting a defined mode for said polarity detection; and

the performing the list decoding process comprises: performing the list decoding process on a subset of the plurality of decoding candidates determined based at least in part on the polarity detection.

15. The method of claim 12, wherein the determining the pattern for polarity detection is based at least in part on a connection state, a signal metric, a device state, a detection history, a communication protocol, or a combination thereof.

16. An apparatus for wireless communication, comprising:

a processor for processing the received data, wherein the processor is used for processing the received data,

a memory in electronic communication with the processor; and

instructions stored in the memory and executable by the processor to cause the apparatus to:

monitoring decoding candidates for a codeword, wherein the codeword corresponds to a received bit metric set and the decoding candidates correspond to a plurality of information bits encoded using a polar code;

determining a composite detection metric for the codeword for the decoding candidate, wherein the composite detection metric is derived from a first subset of bit metrics of an intermediate polarization layer of the polar code; and

determining a classification for performing a list decoding process on the codeword according to the decoding candidates based at least in part on the composite detection metric.

17. The apparatus of claim 16, wherein the determining the classification for performing the list decoding process comprises:

determining to suppress the list decoding process for the decoding candidate.

18. The apparatus of claim 16, wherein the determining the classification for performing the list decoding process comprises:

determining a ranking for performing the list decoding process on the codeword according to the decoding candidate relative to other decoding candidates of a plurality of decoding candidates for a search space.

19. The apparatus of claim 16, wherein the instructions to determine the composite detection metric are executable by the processor to cause the apparatus to:

applying a weighting vector to the first subset of bit metrics.

20. The apparatus of claim 19, wherein the instructions to determine the composite detection metric are executable by the processor to cause the apparatus to:

applying a second weighting vector to a second subset of bit metrics associated with a second intermediate polarization layer of the polar code; and

one or more activation functions are applied to combine the weighted first subset of bit metrics and the weighted second subset of bit metrics.

21. The apparatus of claim 16, wherein the instructions to determine the composite detection metric are executable by the processor to cause the apparatus to:

applying one or more weighting vectors to the first subset of bit metrics to obtain one or more intermediate composite metrics; and

applying one or more activation functions to combine the one or more intermediate metrics to obtain the composite detection metric.

22. The apparatus of claim 16, wherein the instructions to determine the composite detection metric are executable by the processor to cause the apparatus to:

determining a derived bit metric based at least in part on the first bit metric subset and a weighting pattern determined based at least in part on a number of information bits in a subset of leaf nodes corresponding to the first bit metric subset.

23. The apparatus of claim 22, wherein the instructions to determine the composite detection metric are executable by the processor to cause the apparatus to:

applying one or more activation functions to combine the derived bit metrics to obtain the composite detection metric.

24. The apparatus of claim 16, wherein the first subset of bit metrics is determined based at least in part on a single parity operation or a repetition operation from bit metrics at a polarization layer feeding the first intermediate polarization layer.

25. The apparatus of claim 16, wherein the determining the classification for performing the list decoding process comprises:

comparing the composite detection metric to a threshold, wherein the threshold is based at least in part on a connection state, a signal metric, a device state, a detection history, a communication protocol, or a combination thereof.

26. The apparatus of claim 16, wherein the first subset of bit metrics corresponds to log-likelihood ratios (LLRs) of a corresponding subset of bit channels of the polar code.

27. An apparatus for wireless communication, comprising:

a processor for processing the received data, wherein the processor is used for processing the received data,

a memory in electronic communication with the processor; and

instructions stored in the memory and executable by the processor to cause the apparatus to:

receiving a search space comprising a plurality of decoding candidates associated with a polar code;

determining a pattern of polarity detection for the search space, the polarity detection being based at least in part on a composite detection metric of the plurality of decoding candidates, wherein the composite detection metric is derived from respective subsets of bit metrics of the plurality of decoding candidates for at least one intermediate polarization layer of the polar code; and

performing a list decoding process for at least one of the plurality of decoding candidates for the search space based at least in part on the pattern of polarity detection for the search space.

28. The apparatus of claim 27, wherein:

the determining the pattern for polarity detection comprises: selecting a prioritization mode for the polarity detection; and

the performing the list decoding process comprises: performing the list decoding process on the plurality of decoding candidates in an order determined based at least in part on the polarity detection.

29. The apparatus of claim 27, wherein:

the determining the pattern for polarity detection comprises: selecting a defined mode for said polarity detection; and

the performing the list decoding process comprises: performing the list decoding process on a subset of the plurality of decoding candidates determined based at least in part on the polarity detection.

30. The apparatus of claim 27, wherein the determining the pattern for polarity detection is based at least in part on a connection state, a signal metric, a device state, a detection history, a communication protocol, or a combination thereof.

Technical Field

The following generally relates to wireless communications, and more particularly, to efficient polarity detection with dynamic control and optimization.

Background

Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems are capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include fourth generation (4G) systems (e.g., Long Term Evolution (LTE) systems, LTE-advanced (LTE-a) systems, or LTE-a professional systems) and fifth generation (5G) systems (which may be referred to as New Radio (NR) systems). These systems may employ techniques such as: code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), or discrete Fourier transform spread OFDM (DFT-S-OFDM). A wireless multiple-access communication system may include multiple base stations or network access nodes, each supporting communication for multiple communication devices (which may otherwise be referred to as User Equipment (UE)) simultaneously.

In some cases, a UE modem in idle or connected mode may be required to monitor the search space for receiving control information by monitoring multiple blind PDCCH decoding hypotheses for a duration such as a time slot. In some cases, the number of blind PDCCH decodes required per slot may increase proportionally, for example, when operating with multiple carriers (e.g., Carrier Aggregation (CA)). In some cases, existing modem designs may perform brute force decoding for all blind PDCCH hypotheses, even though most decoding candidates may be false. In such cases, the percentage of chip wake-up time utilized due to the number of blind decodes may increase, which may adversely affect latency, power consumption, and/or chip area.

Disclosure of Invention

The described technology relates to improved methods, systems, devices, and apparatus that support efficient polarity detection with dynamic control and optimization. In general, the described techniques provide for receiving and transmitting codewords encoded using polar codes. The encoder obtains a codeword from a plurality of information bits and one or more frozen bits according to a polar code. In some cases, the codeword may be associated with a Physical Downlink Control Channel (PDCCH) carrying Downlink Control Information (DCI). In some aspects, the techniques described herein may utilize one or more characteristics of a polar code in order to optimize the number of blind PDCCH decodes in RRC connection and/or idle mode.

In some cases, a polarity detector may be defined to evaluate the quality of the frozen bit component of the polarity codeword. For example, a composite detection metric for a codeword may be determined based on an observed set of log-likelihood ratios (LLRs) or bit metrics associated with the polar code. In some cases, the composite detection metric may be used to estimate the likelihood of whether the observed set of LLRs are polar codewords. In some aspects, one or more estimators or decoder components (which are then based on the derived LLRs) may be used to define the composite detection metric.

In some embodiments, the UE may determine whether to turn polarity detection on based in part on one or more parameters including Radio Resource Control (RRC) state (i.e., idle or connected), signal-to-noise ratio (SNR), previous polarity detection, cost (e.g., power), etc. For example, the polarity detection feature may be turned off when a particular value of a parameter falls outside of a range of thresholds for turning on polarity detection. The UE may also select between different modes of operation (e.g., prioritized and/or defined) when polarity detection is turned on in order to dynamically control and optimize polarity detection. In some cases, a prioritization scheme may be deployed such that the polarity detector prioritizes the decoding candidate list with rankings based on the estimated metrics. In some other cases, the definition mode may allow the polarity detector to define decoding candidates by hypothesis testing.

A method of wireless communication is described. The method may include: monitoring decoding candidates for a codeword, wherein the codeword corresponds to a received bit metric set and the decoding candidates correspond to a set of information bits encoded using a polar code; determining a composite detection metric for the codeword for the decoding candidate, wherein the composite detection metric is derived from a first subset of bit metrics of an intermediate polarization layer of the polar code; and determining a classification for performing a list decoding process on the codeword according to the decoding candidates based on the composite detection metric.

An apparatus for wireless communication is described. The apparatus may include a processor, a memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to: monitoring decoding candidates for a codeword, wherein the codeword corresponds to a received bit metric set and the decoding candidates correspond to a set of information bits encoded using a polar code; determining a composite detection metric for the codeword for the decoding candidate, wherein the composite detection metric is derived from a first subset of bit metrics of an intermediate polarization layer of the polar code; and determining a classification for performing a list decoding process on the codeword according to the decoding candidates based on the composite detection metric.

Another apparatus for wireless communication is described. The apparatus may include means for: monitoring decoding candidates for a codeword, wherein the codeword corresponds to a received bit metric set and the decoding candidates correspond to a set of information bits encoded using a polar code; determining a composite detection metric for the codeword for the decoding candidate, wherein the composite detection metric is derived from a first subset of bit metrics of an intermediate polarization layer of the polar code; and determining a classification for performing a list decoding process on the codeword according to the decoding candidates based on the composite detection metric.

A non-transitory computer-readable medium storing code for wireless communication is described. The code may include instructions executable by a processor to: monitoring decoding candidates for a codeword, wherein the codeword corresponds to a received bit metric set and the decoding candidates correspond to a set of information bits encoded using a polar code; determining a composite detection metric for the codeword for the decoding candidate, wherein the composite detection metric is derived from a first subset of bit metrics of an intermediate polarization layer of the polar code; and determining a classification for performing a list decoding process on the codeword according to the decoding candidates based on the composite detection metric.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the determining the classification for performing the list decoding process may include operations, features, units, or instructions for: determining to suppress the list decoding process for the decoding candidate.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the determining the classification for performing the list decoding process may include operations, features, units, or instructions for: determining a ranking for performing the list decoding process on the codeword according to the decoding candidates relative to other decoding candidates of a set of decoding candidates for a codeword search space.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, determining the composite detection metric may include operations, features, units, or instructions to: applying a weighting vector to the first subset of bit metrics.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, determining the composite detection metric may include operations, features, units, or instructions to: applying a second weighting vector to a second subset of bit metrics associated with a second intermediate polarization layer of the polar code; and applying one or more activation functions to combine the weighted first subset of bit metrics and the weighted second subset of bit metrics.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, determining the composite detection metric may include operations, features, units, or instructions to: applying one or more weighting vectors to the first subset of bit metrics to obtain one or more intermediate composite metrics; and applying one or more activation functions to combine the one or more intermediate metrics to obtain the composite detection metric.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, determining the composite detection metric may include operations, features, units, or instructions to: determining a derived bit metric based on the first bit metric subset and a weighting pattern determined based on a number of information bits in a subset of leaf nodes corresponding to the first bit metric subset.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, determining the composite detection metric may include operations, features, units, or instructions to: applying one or more activation functions to combine the derived bit metrics to obtain the composite detection metric.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the first subset of bit metrics may be determined based on a single parity operation or a repeat operation from bit metrics at a polarization layer feeding the intermediate polarization layer.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the determining the classification for performing the list decoding process may include operations, features, units, or instructions for: the composite detection metric is compared to a threshold, where the threshold may be based on a connection status, a signal metric, a device status, a detection history, a communication protocol, or a combination thereof.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the first subset of bit metrics corresponds to log-likelihood ratios (LLRs) of a corresponding subset of bit channels of the polar code.

A method of wireless communication is described. The method may include: receiving a search space comprising a set of decoding candidates associated with a polar code; determining a pattern of polarity detection for the search space, the polarity detection being based on a composite detection metric of the set of decoding candidates, wherein the composite detection metric is derived from a respective subset of bit metrics of the set of decoding candidates for at least one intermediate polarization layer of the polar code; and performing a list decoding process for at least one decoding candidate of the set of decoding candidates for the search space based on the mode for polarity detection of the search space.

An apparatus for wireless communication is described. The apparatus may include a processor, a memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to: receiving a search space comprising a set of decoding candidates associated with a polar code; determining a pattern of polarity detection for the search space, the polarity detection being based on a composite detection metric of the set of decoding candidates, wherein the composite detection metric is derived from a respective subset of bit metrics of the set of decoding candidates for at least one intermediate polarization layer of the polar code; and performing a list decoding process for at least one decoding candidate of the set of decoding candidates for the search space based on the mode for polarity detection of the search space.

Another apparatus for wireless communication is described. The apparatus may include means for: receiving a search space comprising a set of decoding candidates associated with a polar code; determining a pattern of polarity detection for the search space, the polarity detection being based on a composite detection metric of the set of decoding candidates, wherein the composite detection metric is derived from a respective subset of bit metrics of the set of decoding candidates for at least one intermediate polarization layer of the polar code; and performing a list decoding process for at least one decoding candidate of the set of decoding candidates for the search space based on the mode for polarity detection of the search space.

A non-transitory computer-readable medium storing code for wireless communication is described. The code may include instructions executable by a processor to: receiving a search space comprising a set of decoding candidates associated with a polar code; determining a pattern of polarity detection for the search space, the polarity detection being based on a composite detection metric of the set of decoding candidates, wherein the composite detection metric is derived from a respective subset of bit metrics of the set of decoding candidates for at least one intermediate polarization layer of the polar code; and performing a list decoding process for at least one decoding candidate of the set of decoding candidates for the search space based on the mode for polarity detection of the search space.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the determining the pattern for the polarity detection comprises: selecting a prioritization mode for the polarity detection, and the performing the list decoding process comprises: performing a list decoding process on the set of decoding candidates in an order determined based on the polarity detection.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the determining the pattern for the polarity detection comprises: selecting a defined mode for the polarity detection, and the performing the list decoding process comprises: performing the list decoding process on a subset of the set of decoding candidates determined based on the polarity detection.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the determining the pattern for the polarity detection may be based on a connection state, a signal metric, a device state, a detection history, a communication protocol, or a combination thereof.

Drawings

Fig. 1 and 2 illustrate examples of systems for wireless communication that support efficient polarity detection with dynamic control and optimization in accordance with aspects of the present disclosure.

Fig. 3 illustrates an example of a polarity detector supporting efficient polarity detection with dynamic control and optimization in accordance with aspects of the present disclosure.

Fig. 4 shows an example of a decoding process according to aspects of the present disclosure.

Fig. 5 illustrates an example of a flow chart supporting efficient polarity detection with dynamic control and optimization in accordance with aspects of the present disclosure.

Fig. 6 and 7 show block diagrams of devices that support efficient polarity detection with dynamic control and optimization, according to aspects of the present disclosure.

Fig. 8 illustrates a block diagram of a communication manager that supports efficient polarity detection with dynamic control and optimization in accordance with aspects of the present disclosure.

Fig. 9 illustrates a diagram of a system including a User Equipment (UE) supporting efficient polarity detection with dynamic control and optimization in accordance with aspects of the present disclosure.

Fig. 10 illustrates a diagram of a system including a base station supporting efficient polarity detection with dynamic control and optimization in accordance with aspects of the present disclosure.

Fig. 11 and 12 show flow diagrams illustrating methods of supporting efficient polarity detection with dynamic control and optimization according to aspects of the present disclosure.

Detailed Description

In some wireless systems, a base station or User Equipment (UE) may transmit a payload containing information to be decoded at a receiving device. In some cases, the information may be Downlink Control Information (DCI) carried on a Physical Downlink Control Channel (PDCCH). In some cases, a UE modem in idle or connected mode may be required to monitor multiple blind PDCCH decoding hypotheses (e.g., decoding candidates for a codeword search space) for a duration such as a time slot. In some cases, the number of blind PDCCH decodes required per slot may also be increased, for example, when operating with multiple carriers (e.g., Carrier Aggregation (CA) using multiple Component Carriers (CCs)). In some cases, the UE may perform a brute force decoding on all blind PDCCH hypotheses, even though most decoding candidates may not correspond to the transmitted PDCCH. In such a case, the percentage of chip wake-up time (e.g., in the DRX cycle) utilized due to the number of blind decodes may be increased.

According to various aspects, a UE decoding a codeword may define one or more types of polarity detector components that may be used to define a general form of composition of a decoder. In some cases, three types of detector components may be defined for the F and G blocks, as follows: vFn and vGn may be used to refer to F and G vectors, respectively, of derived LLRs for an intermediate decoder layer n (e.g., not a root or leaf layer). In some cases, the LLRs for the intermediate decoder layers may be computed using the recursion further described with reference to fig. 4. Further, it should be noted that the F operation (or single parity operation) and the G operation (or repeat operation) may be represented by the left and right sides of the binary tree, while polarity decoding is performed using the binary tree representation. Broadly, a UE decoding a codeword may receive an input set of LLRs (e.g., N LLRs) at a channel or root layer, which may be polarized by F and G operations at intermediate layers. In some aspects, each intermediate layer may be associated with a total of N LLRs, where the LLRs may be grouped into one or more subsets by F and G operations. In some cases, one or more subsets of LLRs (or bit metrics) are updated or polarized as decoding proceeds down the binary tree.

In some cases, estimators sFn and sGn may be used to refer to a scalar of the computed estimated metrics, which may be conditioned on a particular pattern defined by the associated set of information bits in the block. In some cases, estimators dFn _ x and dGn _ x may represent a derived version of the detector components based on the hypothesized bit patterns for the intermediate decoder layers. In some cases, such a derived form may be defined based on a polar code structure (e.g., based on a priori knowledge associated with the locations of the frozen bits).

In some cases, decoder compositions may be defined using one or more estimators based on derived values (including vFn, vGn, sFn, sGn, dFn _ x, and dGn _ x) and one or more weighting modes. In some aspects, the decoder composition may be viewed (or expressed) as a function that operates on the original LLRs. In some cases, the decoder composition may also be expressed using LLRs as: whereinCorresponding to the original LLR for codeword bit X.

Thus, broadly, a polarity detector may be defined to evaluate the quality of the frozen bit component of the polarity codeword. For example, a composite detection metric for a codeword may be determined based on an observed set of log-likelihood ratios (LLRs) or bit metrics associated with intermediate layers of polar codes. In some cases, the composite detection metric may be used to estimate the likelihood of whether the observed set of LLRs is a polar codeword. In some aspects, one or more estimators or decoder components (which are then based on the derived LLRs) as described above may be used to define the composite detection metric.

In some cases, polarity detection may be turned on or off, which may depend on the mode of operation (e.g., RRC state, such as idle state or connected state). In some examples, two modes of operation may be defined for the polarity detector: prioritizing (P) and defining (Q) patterns. In some cases, P-mode may support prioritizing the list of decoding candidates with ranking based on an estimated metric (e.g., LLR). In some aspects, the qualification mode for dynamic control and optimization may enable the polarity detector to qualify (or disqualify) decoding candidates via hypothesis testing. In some aspects, P-mode and Q-mode may assist in optimizing overall blind PDCCH decoding complexity, e.g., in RRC connected and idle modes, respectively.

Aspects of the present disclosure are first described in the context of a wireless communication system. Aspects of the present disclosure are further illustrated by and described with reference to polarity detector structures, decoding processes, apparatus diagrams, system diagrams, and flow diagrams that relate to efficient polarity detection with dynamic control and optimization.

Fig. 1 illustrates an example of a wireless communication system 100 that supports efficient polarity detection with dynamic control and optimization in accordance with aspects of the present disclosure. The wireless communication system 100 includes base stations 105, UEs 115, and a core network 130. In some examples, the wireless communication system 100 may be a Long Term Evolution (LTE) network, an LTE-advanced (LTE-a) network, an LTE-a professional network, or a New Radio (NR) network. In some cases, the wireless communication system 100 may support enhanced broadband communications, ultra-reliable (e.g., mission critical) communications, low latency communications, or communications with low cost and low complexity devices.

The base station 105 may communicate wirelessly with the UE115 via one or more base station antennas. The base stations 105 described herein may include or may be referred to by those skilled in the art as base station transceivers, radio base stations, access points, radio transceivers, node bs, evolved node bs (enbs), next generation node bs or gigabit node bs (any of which may be referred to as gnbs), home node bs, home evolved node bs, or some other suitable terminology. The wireless communication system 100 may include different types of base stations 105 (e.g., macro cell base stations or small cell base stations). The UE115 described herein is capable of communicating with various types of base stations 105 and network devices, including macro enbs, small cell enbs, gnbs, relay base stations, and the like.

Each base station 105 may be associated with a particular geographic coverage area 110 in which communications with various UEs 115 are supported. Each base station 105 may provide communication coverage for a respective geographic coverage area 110 via a communication link 125, and the communication link 125 between the base station 105 and the UE115 may utilize one or more carriers. The communication links 125 shown in the wireless communication system 100 may include: uplink transmissions from the UE115 to the base station 105, or downlink transmissions from the base station 105 to the UE 115. Downlink transmissions may also be referred to as forward link transmissions, and uplink transmissions may also be referred to as reverse link transmissions.

The geographic coverage area 110 for a base station 105 can be divided into sectors that form only a portion of the geographic coverage area 110, and each sector can be associated with a cell. For example, each base station 105 may provide communication coverage for a macro cell, a small cell, a hot spot, or other type of cell, or various combinations thereof. In some examples, the base stations 105 may be mobile and, thus, provide communication coverage for a moving geographic coverage area 110. In some examples, different geographic coverage areas 110 associated with different technologies may overlap, and the overlapping geographic coverage areas 110 associated with different technologies may be supported by the same base station 105 or different base stations 105. The wireless communication system 100 may include, for example, heterogeneous LTE/LTE-a professional or NR networks, where different types of base stations 105 provide coverage for various geographic coverage areas 110.

The term "cell" refers to a logical communication entity used for communication with the base station 105 (e.g., on a carrier) and may be associated with an identifier (e.g., Physical Cell Identifier (PCID), Virtual Cell Identifier (VCID)) used to distinguish neighboring cells operating via the same or different carrier. In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., Machine Type Communication (MTC), narrowband internet of things (NB-IoT), enhanced mobile broadband (eMBB), or other protocol types) that may provide access for different types of devices. In some cases, the term "cell" may refer to a portion (e.g., a sector) of geographic coverage area 110 over which a logical entity operates.

UEs 115 may be dispersed throughout the wireless communication system 100, and each UE115 may be stationary or mobile. The UE115 may also be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable terminology, where a "device" may also be referred to as a unit, station, terminal, or client. The UE115 may also be a personal electronic device, such as a cellular telephone, a Personal Digital Assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some examples, the UE115 may also refer to a Wireless Local Loop (WLL) station, an internet of things (IoT) device, an internet of everything (IoE) device, or an MTC device, etc., which may be implemented in various items such as appliances, vehicles, meters, etc.

Some UEs 115 (e.g., MTC or IoT devices) may be low cost or low complexity devices and may provide automated communication between machines (e.g., communication via machine-to-machine (M2M)). M2M communication or MTC may refer to data communication techniques that allow devices to communicate with each other or base station 105 without human intervention. In some examples, M2M communication or MTC may include communication from devices that integrate sensors or meters to measure or capture information and relay that information to a central server or application that may utilize the information or present the information to a human interacting with the program or application. Some UEs 115 may be designed to collect information or implement automated behavior of machines. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, device monitoring, healthcare monitoring, wildlife monitoring, climate and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based billing for services.

Some UEs 115 may be configured to employ a reduced power consumption mode of operation, such as half-duplex communication (e.g., a mode that supports unidirectional communication via transmission or reception rather than simultaneous transmission and reception). In some examples, half-duplex communication may be performed at a reduced peak rate. Other power saving techniques for the UE115 include: a power-saving "deep sleep" mode is entered when not engaged in active communications or operating on a limited bandwidth (e.g., according to narrowband communications). In some cases, the UE115 may be designed to support critical functions (e.g., mission critical functions), and the wireless communication system 100 may be configured to provide ultra-reliable communication for these functions.

In some cases, the UE115 may also be able to communicate directly with other UEs 115 (e.g., using peer-to-peer (P2P) or device-to-device (D2D) protocols). One or more UEs 115 in the group of UEs 115 communicating with D2D may be within the geographic coverage area 110 of the base station 105. Other UEs 115 in such a group may be outside the geographic coverage area 110 of the base station 105 or otherwise unable to receive transmissions from the base station 105. In some cases, multiple groups of UEs 115 communicating via D2D communication may utilize a one-to-many (1: M) system, where each UE115 transmits to every other UE115 in the group. In some cases, the base station 105 facilitates scheduling of resources for D2D communication. In other cases, D2D communication is performed between UEs 115 without involving base stations 105.

The base stations 105 may communicate with the core network 130 and with each other. For example, the base stations 105 may interface with the core network 130 over backhaul links 132 (e.g., via S1, N2, N3, or other interfaces). The base stations 105 may communicate with each other directly (e.g., directly between base stations 105) or indirectly (e.g., via the core network 130) over backhaul links 134 (e.g., via X2, Xn, or other interfaces).

Core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. Core network 130 may be an Evolved Packet Core (EPC) that may include at least one Mobility Management Entity (MME), at least one serving gateway (S-GW), and at least one Packet Data Network (PDN) gateway (P-GW). The MME may manage non-access stratum (e.g., control plane) functions such as mobility, authentication, and bearer management for UEs 115 served by base stations 105 associated with the EPC. User IP packets may be transported through the S-GW, which may itself be connected to the P-GW. The P-GW may provide IP address assignment as well as other functions. The P-GW may be connected to a network operator IP service. The operator IP services may include access to the internet, intranets, IP Multimedia Subsystem (IMS) or Packet Switched (PS) streaming services.

At least some of the network devices (e.g., base stations 105) may include subcomponents such as access network entities, which may be examples of Access Node Controllers (ANCs). Each access network entity may communicate with the UE115 through a plurality of other access network transport entities, which may be referred to as radio heads, intelligent radio heads, or transmission/reception points (TRPs). In some configurations, the various functions of each access network entity or base station 105 may be distributed across various network devices (e.g., radio heads and access network controllers) or consolidated into a single network device (e.g., base station 105).

The wireless communication system 100 may operate using one or more frequency bands (typically in the range of 300MHz to 300 GHz). Typically, the region from 300MHz to 3GHz is referred to as the Ultra High Frequency (UHF) region or decimeter band because the wavelength range is from approximately one decimeter to one meter in length. UHF waves may be blocked or redirected by building and environmental features. However, the waves may be sufficient to penetrate the structure for the macro cell to provide service to the UE115 located indoors. UHF-wave transmission can be associated with smaller antennas and shorter distances (e.g., less than 100km) than transmission of smaller and longer waves using the High Frequency (HF) or Very High Frequency (VHF) portions of the spectrum below 300 MHz.

The wireless communication system 100 may also operate in the ultra high frequency (SHF) region using a frequency band from 3GHz to 30GHz, also referred to as a centimeter frequency band. The SHF area includes frequency bands such as the 5GHz industrial, scientific, and medical (ISM) band, which may be opportunistically used by devices that can tolerate interference from other users.

The wireless communication system 100 may also operate in the Extremely High Frequency (EHF) region of the spectrum, e.g., from 30GHz to 300GHz (also referred to as the millimeter-band). In some examples, the wireless communication system 100 may support millimeter wave (mmW) communication between the UE115 and the base station 105, and EHF antennas of respective devices may be even smaller and more closely spaced compared to UHF antennas. In some cases, this may facilitate the use of antenna arrays within the UE 115. However, the propagation of EHF transmissions may suffer from even greater atmospheric attenuation and shorter distances than SHF or UHF transmissions. The techniques disclosed herein may be employed across transmissions using one or more different frequency regions, and the specified use of frequency bands across these frequency regions may differ depending on the country or regulatory agency.

In some cases, the wireless communication system 100 may utilize both licensed and unlicensed radio frequency spectrum bands. For example, the wireless communication system 100 may employ Licensed Assisted Access (LAA), LTE unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed band (e.g., the 5GHz ISM band). When operating in the unlicensed radio frequency spectrum band, wireless devices (e.g., base station 105 and UE115) may employ a Listen Before Talk (LBT) procedure to ensure that the frequency channel is idle before transmitting data. In some cases, operation in the unlicensed band may be based on CA configurations in conjunction with CCs operating in a licensed band (e.g., LAA). Operations in the unlicensed spectrum may include downlink transmissions, uplink transmissions, peer-to-peer transmissions, or a combination of these. Duplexing in the unlicensed spectrum may be based on Frequency Division Duplexing (FDD), Time Division Duplexing (TDD), or a combination of both.

In some examples, a base station 105 or UE115 may be equipped with multiple antennas, which may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communication, or beamforming. For example, the wireless communication system 100 may use a transmission scheme between a transmitting device (e.g., base station 105) and a receiving device (e.g., UE115), where the transmitting device is equipped with multiple antennas and the receiving device is equipped with one or more antennas. MIMO communication may employ multipath signal propagation to improve spectral efficiency by transmitting or receiving multiple signals via different spatial layers, which may be referred to as spatial multiplexing. For example, a transmitting device may transmit multiple signals via different antennas or different combinations of antennas. Likewise, a receiving device may receive multiple signals via different antennas or different combinations of antennas. Each of the multiple signals may be referred to as a separate spatial stream and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams. Different spatial layers may be associated with different antenna ports for channel measurement and reporting. MIMO techniques include single-user MIMO (SU-MIMO), in which multiple spatial layers are transmitted to the same receiving device, and multi-user MIMO (MU-MIMO), in which multiple spatial layers are transmitted to multiple devices.

Beamforming (which may also be referred to as spatial filtering, directional transmission or directional reception) is a signal processing technique that: the techniques may be used at a transmitting device or a receiving device (e.g., base station 105 or UE115) to form or steer an antenna beam (e.g., a transmit beam or a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by: signals transmitted via the antenna elements of the antenna array are combined such that signals propagating in a particular orientation relative to the antenna array experience constructive interference while other signals experience destructive interference. The adjustment of the signal transmitted via the antenna element may comprise: a transmitting device or a receiving device applies certain amplitude and phase offsets to signals carried via each of the antenna elements associated with the device. The adjustments associated with each of the antenna elements may be defined by a set of beamforming weights associated with a particular orientation (e.g., relative to an antenna array of a transmitting device or a receiving device, or relative to some other orientation).

In one example, the base station 105 may use multiple antennas or antenna arrays for beamforming operations for directional communication with the UE 115. For example, the base station 105 may transmit some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) multiple times in different directions, which may include signals transmitted according to different sets of beamforming weights associated with different transmission directions. Transmissions in different beam directions may be used to identify beam directions (e.g., by the base station 105 or a receiving device (e.g., UE 115)) for subsequent transmission and/or reception by the base station 105. The base station 105 may transmit some signals (e.g., data signals associated with a particular receiving device) in a single beam direction (e.g., a direction associated with the receiving device (e.g., UE 115)). In some examples, a beam direction associated with a transmission along a single beam direction may be determined based at least in part on signals transmitted in different beam directions. For example, the UE115 may receive one or more of the signals transmitted in different directions by the base station 105, and the UE115 may report an indication to the base station 105 of the signal it receives with the highest or otherwise acceptable signal quality. Although the techniques are described with reference to signals transmitted by the base station 105 in one or more directions, the UE115 may employ similar techniques to transmit signals multiple times in different directions (e.g., to identify beam directions for subsequent transmission or reception by the UE115) or to transmit signals in a single direction (e.g., to transmit data to a receiving device).

When receiving various signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) from the base station 105, a receiving device (e.g., UE115, which may be an example of a mmW receiving device) may attempt multiple receive beams. For example, the receiving device may attempt multiple receive directions by receiving via different antenna sub-arrays, by processing received signals according to different antenna sub-arrays, by receiving according to different sets of receive beamforming weights applied to signals received at multiple antenna elements of an antenna array, or by processing received signals according to different sets of receive beamforming weights applied to signals received at multiple antenna elements of an antenna array (any of the above operations may be referred to as "listening" according to different receive beams or receive directions). In some examples, a receiving device may use a single receive beam to receive along a single beam direction (e.g., when receiving data signals). The single receive beam may be aligned in a beam direction determined based at least in part on listening from different receive beam directions (e.g., a beam direction determined to have the highest signal strength, the highest signal-to-noise ratio, or otherwise acceptable signal quality based at least in part on listening from multiple beam directions).

In some cases, the antennas of a base station 105 or UE115 may be located within one or more antenna arrays that may support MIMO operation or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower. In some cases, the antennas or antenna arrays associated with the base station 105 may be located at different geographic locations. The base station 105 may have an antenna array with multiple rows and columns of antenna ports that the base station 105 may use to support beamforming for communications with the UEs 115. Likewise, the UE115 may have one or more antenna arrays that may support various MIMO or beamforming operations.

In some cases, the wireless communication system 100 may be a packet-based network operating according to a layered protocol stack. In the user plane, communications at the bearer or Packet Data Convergence Protocol (PDCP) layer may be IP-based. In some cases, the Radio Link Control (RLC) layer may perform packet segmentation and reassembly to communicate on logical channels. A Medium Access Control (MAC) layer may perform priority processing and multiplexing of logical channels to transport channels. The MAC layer may also use hybrid automatic repeat request (HARQ) to provide retransmissions at the MAC layer to improve link efficiency. In the control plane, a Radio Resource Control (RRC) protocol layer may provide for the establishment, configuration, and maintenance of RRC connections between the UE115 and the base station 105 or core network 130 that support radio bearers for user plane data. At the Physical (PHY) layer, transport channels may be mapped to physical channels.

In some cases, the UE115 and the base station 105 may support retransmission of data to increase the likelihood that the data is successfully received. HARQ feedback is a technique that increases the likelihood that data will be received correctly on the communication link 125. HARQ may include a combination of error detection (e.g., using Cyclic Redundancy Check (CRC)), Forward Error Correction (FEC), and retransmission (e.g., automatic repeat request (ARQ)). HARQ may improve throughput at the MAC layer under poor radio conditions (e.g., signal and noise conditions). In some cases, a wireless device may support same slot HARQ feedback, where the device may provide HARQ feedback in a particular slot for data received in a previous symbol in the slot. In other cases, the device may provide HARQ feedback in subsequent time slots or according to some other time interval.

May be in basic time units (which may, for example, refer to T)_sA sampling period of 1/30,720,000 seconds) to represent the time interval in LTE or NR. The time intervals of the communication resources may be organized according to radio frames each having a duration of 10 milliseconds (ms), where the frame period may be denoted T_f＝307,200T_s. The radio frames may be identified by a System Frame Number (SFN) ranging from 0 to 1023. Each frame may include 10 subframes numbered from 0 to 9, and each subframe may have a duration of 1 ms. A subframe may also be divided into 2 slots, each having a duration of 0.5ms, and each slot may contain 6 or 7 modulation symbol periods (e.g., depending on the length of the cyclic prefix added in front of each symbol period). Each symbol period may contain 2048 sample periods, excluding the cyclic prefix. In some cases, a subframe may be the smallest scheduling unit of the wireless communication system 100 and may be referred to as a Transmission Time Interval (TTI). In other cases, the minimum scheduling unit of the wireless communication system 100 may be shorter than a subframe or may be dynamically selected (e.g., in a burst of shortened ttis (sTTI) or in a selected component carrier using sTTI).

In some wireless communication systems, a slot may be further divided into a plurality of minislots comprising one or more symbols. In some examples, the symbol of the micro-slot or the micro-slot may be a minimum scheduling unit. Each symbol may vary in duration depending on, for example, the subcarrier spacing or frequency band of operation. Further, some wireless communication systems may implement timeslot aggregation, where multiple timeslots or minislots are aggregated together and used for communication between the UE115 and the base station 105.

The term "carrier" refers to a set of radio frequency spectrum resources having a defined physical layer structure for supporting communications over the communication link 125. For example, the carrier of the communication link 125 may include a portion of the radio frequency spectrum band that operates according to physical layer channels for a given radio access technology. Each physical layer channel may carry user data, control information, or other signaling. The carriers may be associated with predefined frequency channels (e.g., E-UTRA absolute radio frequency channel numbers (EARFCNs)) and may be placed according to a channel grid for discovery by UEs 115. The carriers may be downlink or uplink (e.g., in FDD mode), or may be configured to carry downlink and uplink communications (e.g., in TDD mode). In some examples, the signal waveform transmitted on a carrier may be made up of multiple subcarriers (e.g., using multicarrier modulation (MCM) techniques such as OFDM or DFT-s-OFDM).

The organization of carriers may be different for different radio access technologies (e.g., LTE-A, LTE-a specialty, NR, etc.). For example, communications over carriers may be organized according to TTIs or slots, each of which may include user data as well as control information or signaling to support decoding of the user data. The carriers may also include dedicated acquisition signaling (e.g., synchronization signals or system information, etc.) and control signaling that coordinates operation with respect to the carriers. In some examples (e.g., in a carrier aggregation configuration), a carrier may also have acquisition signaling or control signaling that coordinates operations for other carriers.

The physical channels may be multiplexed on the carriers according to various techniques. For example, physical control channels and physical data channels may be multiplexed on a downlink carrier using Time Division Multiplexing (TDM) techniques, Frequency Division Multiplexing (FDM) techniques, or hybrid TDM-FDM techniques. In some examples, the control information sent in the physical control channel may be distributed in a cascaded manner between different control regions (e.g., between a common control region or common search space and one or more UE-specific control regions or UE-specific search spaces).

The carrier may be associated with a particular bandwidth of the radio frequency spectrum, and in some examples, the carrier bandwidth may be referred to as the carrier or "system bandwidth" of the wireless communication system 100. For example, the carrier bandwidth may be one of a plurality of predetermined bandwidths (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80MHz) of the carrier for a particular radio access technology. In some examples, each served UE115 may be configured to operate over part or all of the carrier bandwidth. In other examples, some UEs 115 may be configured for operation using a narrowband protocol type associated with a predefined portion or range within a carrier (e.g., a set of subcarriers or RBs) (e.g., "in-band" deployment of narrowband protocol types).

In a system employing MCM technology, a resource element may consist of one symbol period (e.g., the duration of one modulation symbol) and one subcarrier, where the symbol period and subcarrier spacing are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme). Thus, the more resource elements the UE115 receives and the higher the order of the modulation scheme, the higher the data rate may be for the UE 115. In a MIMO system, wireless communication resources may refer to a combination of radio frequency spectrum resources, time resources, and spatial resources (e.g., spatial layers), and the use of multiple spatial layers may further increase the data rate for communication with the UE 115.

Devices of the wireless communication system 100 (e.g., base stations 105 or UEs 115) may have a hardware configuration that supports communication over a particular carrier bandwidth or may be configurable to support communication over one of a set of carrier bandwidths. In some examples, the wireless communication system 100 may include a base station 105 and/or a UE115 capable of supporting simultaneous communication via carriers associated with more than one different carrier bandwidth.

The wireless communication system 100 may support communication with UEs 115 over multiple cells or carriers (a feature that may be referred to as Carrier Aggregation (CA) or multi-carrier operation). According to a carrier aggregation configuration, a UE115 may be configured with multiple downlink CCs and one or more uplink CCs. Carrier aggregation may be used with both FDD and TDD component carriers.

In some cases, the wireless communication system 100 may utilize an enhanced component carrier (eCC). An eCC may be characterized by one or more features including: a wider carrier or frequency channel bandwidth, a shorter symbol duration, a shorter TTI duration, or a modified control channel configuration. In some cases, an eCC may be associated with a carrier aggregation configuration or a dual connectivity configuration (e.g., when multiple serving cells have suboptimal or non-ideal backhaul links). An eCC may also be configured for use in unlicensed spectrum or shared spectrum (e.g., where more than one operator is allowed to use the spectrum). An eCC characterized by a wide carrier bandwidth may include one or more segments that may be used by UEs 115 that may not be able to monitor the entire carrier bandwidth or otherwise be configured to use a limited carrier bandwidth (e.g., to save power).

In some cases, an eCC may utilize a different symbol duration than other CCs, which may include using a reduced symbol duration compared to the symbol durations of the other CCs. Shorter symbol durations may be associated with increased spacing between adjacent subcarriers. A device utilizing an eCC (e.g., UE115 or base station 105) may transmit a wideband signal (e.g., according to a frequency channel or carrier bandwidth of 20, 40, 60, 80MHz, etc.) with a reduced symbol duration (e.g., 16.67 microseconds). A TTI in an eCC may consist of one or more symbol periods. In some cases, the TTI duration (i.e., the number of symbol periods in a TTI) may be variable.

In addition, wireless communication systems (such as NR systems) may utilize any combination of licensed, shared, and unlicensed spectrum bands. Flexibility in eCC symbol duration and subcarrier spacing may allow eCC to be used across multiple frequency spectrums. In some examples, NR sharing spectrum may improve spectrum utilization and spectral efficiency, particularly through dynamic vertical (e.g., across the frequency domain) and horizontal (e.g., across the time domain) sharing of resources.

In some cases, an encoder within a wireless device (such as base station 105 or UE115) may obtain a codeword from a plurality of information bits and one or more frozen bits according to a polar code. In some cases, the codeword may be associated with a Physical Downlink Control Channel (PDCCH) carrying Downlink Control Information (DCI). In some aspects, one or more characteristics of the polar code may be utilized in order to optimize the number of blind PDCCH decodes in RRC connected and/or idle mode, for example, when deploying carrier aggregation.

In some cases, a polarity detector may be defined to evaluate the quality of the frozen bit component of the polarity codeword. For example, a composite detection metric for a codeword may be determined based on an observed set of log-likelihood ratios (LLRs) or bit metrics associated with the polar code. In some cases, the composite detection metric may be used to estimate the likelihood of whether the observed set of LLRs is a polar codeword. In some aspects, one or more estimators or decoder components (which are then based on the derived LLRs) may be used to define the composite detection metric.

According to some aspects, the UE115 may determine whether to turn polarity detection on based in part on one or more parameters including a Radio Resource Control (RRC) state (i.e., idle or connected), a signal-to-noise ratio (SNR), previous polarity detection, cost (e.g., power), and so on. In some examples, the threshold for derivation of the polarity detection feature may be determined using previous polarity detection and cost parameter values. Polarity detection may be turned off when the value estimated by the detector falls outside the range of the derived threshold for turning on polarity detection. The UE may also select between different operating modes (e.g., P and/or Q) when polarity detection is turned on in order to dynamically control and optimize polarity detection. In some cases, P-mode may be deployed such that the polarity detector prioritizes the decoding candidate list with rankings based on the estimated metrics. In some other cases, the Q mode may allow the polarity detector to define decoding candidates by hypothesis testing.

Fig. 2 illustrates an example of a wireless communication system 200 that supports efficient polarity detection with dynamic control and optimization in accordance with aspects of the present disclosure. In some examples, the wireless communication system 200 may implement aspects of the wireless communication system 100 and may include a UE 115-a and a base station 105-a, which may be examples of the UE115 and base station 105 as described above with reference to fig. 1. The UE 115-a and the base station 105-a may communicate with each other over a communication link 225.

As shown, the device 200 includes a memory 205, an encoder/decoder 210, and a transmitter/receiver 215. In some cases, a first bus 220 may connect the memory 205 to the encoder/decoder 210, and a second bus 230 may connect the encoder/decoder 210 to the transmitter/receiver 215. In some cases, device 200 may have data stored in memory 205 to be transmitted to another device (such as UE115 or base station 105). To initiate the transfer process, device 200 may retrieve data for transfer (e.g., via first bus 220) from memory 205. As shown, the number of data bits may be represented as a value "k" and may additionally include error correction bits (e.g., Cyclic Redundancy Check (CRC) bits). Encoder/decoder 210 may encode the number of information bits using a polar code having a length "N" (which may be different from or the same as "k"). The polar code may have "N" bit channels, where "k" bit channels are information bit channels used to map "k" data bits. The bit channels that are not allocated as information bits (i.e., N-k bits) may be assigned as either frozen bits or parity bits. In some cases, information bits may be assigned to the k most reliable bit channels, and frozen bits or parity bits may be assigned to the remaining bit channels. The frozen bits may be bits having default values (0, 1, etc.) known to both the encoder and decoder (i.e., the encoder that encodes the information bits at the transmitter and the decoder that decodes the received codeword at the receiver). The parity bits may be values derived from one or more information bits. Further, from the perspective of a receiving device, device 200 may receive encoded data via receiver 215 and decode the encoded data using decoder 210 to obtain transmitted data (e.g., transmitted by transmitter 215 from a different device 200).

In some wireless systems, the decoder 210 may be an example of a Successive Cancellation (SC) or SC list (SCL) decoder. The UE115 or base station 105 may receive the transmission including the codeword at the receiver 215 and may send the transmission to an SC or SCL decoder (e.g., decoder 210). Decoder 210 may determine input (e.g., unpolarized) LLRs for a bit channel of a received codeword. Decoder 210 may decode codeword LLRs according to a hypothesis of a polar code (e.g., an N, k hypothesis), which may be referred to as a decoding candidate. The decoder may perform multiple (e.g., blind) decoding operations on multiple decoding candidates of the codeword search space. During decoding, decoder 210 may determine decoded LLRs based on the input LLRs, where a decoded LLR corresponds to each polarized bit channel of the polar code. These decoded LLRs may be referred to as bit metrics. In some cases, if the LLR is zero or a positive value, the decoder 210 may determine that the corresponding bit is a 0 bit, and a negative LLR may correspond to a 1 bit. The decoder 210 may use the bit metrics to determine the decoded bit values. In some cases, each intermediate layer may be associated with the same number of decoded LLRs as the number of input LLRs (e.g., N LLRs), but they may not be derived all at once. For example, a subset of bit metrics from an intermediate polarization layer may be used to derive another subset of bit metrics from the same (or a different) layer. In particular, a first subset of bit metrics (or LLRs) associated with an intermediate polarization layer may be polarized by F and/or G operations, and based thereon, a next subset of bit metrics for the same or a different intermediate polarization layer may be derived. In some aspects, bit metrics or LLR polarization across different intermediate polarization layers may be observed as decoding proceeds down the binary tree.

The SCL decoder may employ multiple concurrent SC decoding processes. Due to the combination of multiple SC decoding processes, the SCL decoder may compute multiple list candidates for a given decoding candidate. For example, an SCL decoder with a list size of "L" (i.e., the SCL decoder performs L SC decoding processes) may calculate L list candidates and a corresponding reliability metric (e.g., a path metric) for each list candidate. The path metric may represent the reliability of the list candidate or the probability that the corresponding list candidate is the correct set of decoded bits. The path metric may be based on the determined bit metric and the selected bit value at each bit channel. The SCL decoder may have a number of levels equal to the number of bit channels in the received codeword. At each level, the L list candidates may be expanded with 0 and 1 values, respectively, to generate 2L list candidates. A new set of L list candidates may be selected from the 2L list candidates based on the path metric. For example, the SCL decoder may select the list candidate with the highest path metric.

Due to the LLR derivation dependencies, each SC decoding process may decode the codewords sequentially (e.g., in order of bit channel indices). That is, because the first bit channel depends on the input LLRs and undecoded bits, each SC decoding process may first decode the bits corresponding to the first bit channel. Decoding the bits for each subsequent bit channel depends on the feedback of the previously decoded bits. For example, decoding bits for the second bit channel depends on feedback from decoding the first bit channel, decoding bits for the third bit channel depends on feedback from decoding the first and second bit channels, and so on. In this way, information encoded in a bit channel having a lower index can be decoded earlier than information encoded in a bit channel having a higher index based on the sequential characteristic of SC polarity decoding. Thus, in some aspects, the soft values received from the channel and the internal exchange information within the decoder may be considered LLRs. Further, at each stage in the binary tree, LLR values may be sent from the parent node to the child nodes (i.e., from an upper layer to a lower layer), while hard decision values may be up in the layer.

In some cases, a polarity detector may be defined that includes one or more types of detector components defined as follows: vFn and vGn may be used to refer to F and G vectors, respectively, of derived LLRs for an intermediate decoder layer n (e.g., not a root or leaf layer). In some cases, a composite detection metric for decoding candidate codewords may be determined based on a subset of bit metrics of an intermediate polarization layer of a polar code. For example, a composite detection metric may be determined by applying a weighting vector to a subset of bit metrics. In some other cases, a linear combination of subsets of bit metrics may be used to determine a composite detection metric. In some cases, a composite detection metric may be determined from derived bit metrics, which may be based at least in part on a subset of bit metrics and a weighting pattern. In some cases, the weighting pattern may be determined based at least in part on a number of information bits in a subset of leaf nodes corresponding to the subset of bit metrics.

In some cases, a composite detection metric may be determined from one or more intermediate metric calculations. In some aspects, the process for determining a composite detection metric may involve using a weighted combination of a subset of bit metrics followed by one or more activation operations. In some cases, machine learning techniques may be deployed (e.g., by using artificial neural networks) for determining composite detection metrics. In some cases, an artificial neural network may utilize an activation function (or operation) to determine how relevant (or irrelevant) the information received by an artificial neuron (i.e., a mathematical function conceived of a neuron) is. Further, in some examples, the activation operation may involve using a non-linear transformation. Thus, in some aspects, a composite detection metric may be broadly considered as a combination of one or more weighting vectors applied to a subset of bit metrics, where the combination of weighted bit metrics may be updated by using an activation function. In some cases, using a non-linear function rather than a linear function may allow for back propagation (i.e., updating weights based on error), which may be used to improve decoder and/or detector performance. In some other cases, the composite detection metric may be viewed as a weighted combination of one or more subsets of bit metrics (e.g., a first subset of bit metrics associated with a first intermediate polarization layer of the polar code, a second subset of bit metrics associated with a second intermediate polarization layer, etc.), where the respective weights (or weight vectors) may be updated via an activation function.

In some cases, a weight vector for computing the composite detection metric may be indicated to the UE 115-a by the base station 105-a, where the weight vector may be updated (e.g., from one codeword to the next codeword) by an activation function used at the base station. In some cases, the activation function may adjust the weighting vector based on, for example, feedback related to decoding performance experienced at the UE 115-a. In some other cases, the UE 115-a may feed information related to its decoding performance (e.g., recent or historical) in order to teach the activation function to make a more informed decision for determining the weights (or weight vectors).

In some cases, it is possible to use: vF128, vF64, vF32, vF16, vG16, etc. (which are vectors of derived LLRs associated with F or G reference blocks in a vector structure) to define a proposed estimator of a polarity detector. For example, vF32 may be a vector that includes 32 derived LLRs associated with block F32. Similarly, in some cases, sF64, sF32, etc. may be used to refer to a scalar of calculated estimated metrics, which may be conditioned on a particular pattern defined by the associated set of information bits for the block. For example, the estimator sF64 ═ Σ_i(elem_iin vF64)。

The mode may be selected based on the number of information bits in the block. For example, for block F16 with two information bits, dF16a and dF16b may be expressed as: dF16_ a ═ Q_even+Q_odd| and dF16_ b | Q_even–Q_oddL, wherein: q_even＝∑_{i even}(elem_iin vF16) and Q_odd＝∑_{i odd}(elemiin vF16)。

In some cases, polarity detection may be performed using one or more combinations of the proposed estimators, as further described with reference to fig. 3.

In some cases, decoder compositions are defined using one or more estimators based on derived values (including vFn, vGn, sFn, sGn, dFn _ x, and dGn _ x) and one or more weighting modes. For example, the decoder composition may be defined as: w is a₀*vFn+w₁*vGn+w₂*sFn+w₃*sGn+w₄*dFn_x+w₅dGn _ x, wherein the weight w_iI e {0, 1. } may be predetermined (e.g., statically). In some cases, one or more optimization techniques may be used to determine the associated weights for the decoder components. For example, the weighting pattern may be based in part on the number of information bits in a subset of leaf nodes (i.e., the lowest layer) corresponding to a particular block. In some aspects, the decoder composition may be viewed (or expressed) as a function operating on the original LLRs, and the derived LLRs may be based at least in part on the subset of original LLRs and the weighting mode. In some cases, the decoder composition may also be expressed using LLRs as:

in some cases, a combination of signed and unsigned vectors and scalars may also be used to represent decoder compositions. In one example, the decoder composition may be expressed as: fdec ∑ i ∈ SET { vF ∈ SET {_i}W_vFi*vF_i+∑i∈SET{vG_i}W_vGi*vG_i+∑i∈SET{sF_i}w_sFi*sF_i+∑i∈SET{sG_i}w_sGi*sG_i+∑i∈SET{dF_i}w_dFi*dF_i+∑i∈SET{dG_i}w_dGi*dG_iWherein W is_vFiAnd W_vGiIs an unsigned row vector; v_FiAnd V_GiIs a signed column vector; w is a_sFi、w_sGi、w_dFiAnd w_dGiIs an unsigned scalar; and sF_i、sG_i、dF_i、dG_iIs a signed scalar quantity.

In some cases, the decoder composition may be defined using different weighting vectors applied to different subsets of bit metrics across one or more polarization layers of the polar code. Further, the weight vector (or weights) may be updated based on applying one or more activation functions. For example, the composite detection metric may be represented as a combination of the weighted first and second subsets of bit metrics associated with the first and second intermediate polarization layers of the polar code. In some cases, the weighted first and second bit metric subsets may be obtained by applying first and second weighting vectors to the bit metric subsets. Further, a composite detection metric may be determined by applying one or more activation functions to combine the weighted first and second subsets of bit metrics, wherein the activation functions may be used to control the effect of each weighted subset on the composite metric.

In some examples, to support dynamic control and optimization, the performance of the polarity detector may be derived by a weighted combination of errors. Further, the optimal performance threshold may be calculated based on one or more factors, such as the type of deployment (low latency or mobile broadband) and/or RRC state. In some cases, the performance of dynamic threshold control for polar decoding may be based on the detector composition, the type or combination of conditional errors P (H0| H1) and P (H1| H0). It should be noted that it is assumed that H0 may be associated with signals that do not have an active polarity structure, while H1 may be associated with signals that have an active polarity structure. Thus, P (H0| H1) may be a probability of not detecting a polar structure (i.e., missing detection) when the associated decoding candidate corresponds to a polar codeword, and P (H1| H0) may be a probability of detecting a polar structure (i.e., false alarm) when the associated decoding candidate does not correspond to a polar codeword.

In some cases, a descrambled signal without a valid polarity structure may be due to the use of an invalid polarity codeword (e.g., due to a mismatched blind hypothesis or no polarity signal). In some other cases, the invalid polarity structure may be due to the application of a valid codeword with a non-matching sequence to the signal (e.g., during scrambling and/or descrambling). In some cases, prior detection (e.g., R0 and R1) and error cost for polarity encoded codewordsThe parameters of (e.g., C01 and C10) may be based in part on dynamic operation, such as operating mode (e.g., idle or connected, eMBB or mMTC, etc.)_errCan be defined as: c_err＝P₀₁*R₁*C₀₁+P₁₀*R₀*C₁₀. In some aspects, different modes of operation may use different weights for false alarms and/or missed detections. In such a case, there may be different target operating points (i.e., for switching between on and off) for the different modes. In some aspects, R_ijAnd C_ijThe value of (i.e., previous polarity detection and error cost) may be based on the mode of operation used for the best decision, such as idle or connected state, eMBB or mtc transport protocol, etc. In some examples, the outer loop logic may also be deployed concurrently with the selection of the parameter values.

In some cases, the deployment of the polarity detection feature may switch between on and off, and may depend on the mode of operation. In one example, the polarity detection feature may be turned off when the particular parameter values and cost of the previous polarity detection result in a derived threshold that falls outside of the range of values estimated by the detector.

In some examples, two modes of operation may be defined for the polarity detector: p-mode and Q-mode. In some cases, the pattern may be deployed based on an on polarity detection feature. In some cases, P-mode may support prioritizing the list of decoding candidates with ranking based on an estimated metric (e.g., LLR). In some cases, determining the pattern for polarity detection may include selecting a defined pattern for polarity detection. In some aspects, the qualification mode for dynamic control and optimization may enable the polarity detector to qualify (or disqualify) decoding candidates via hypothesis testing. In some aspects, P-mode or Q-mode may assist in optimizing overall blind PDCCH decoding complexity, e.g., in RRC connected and idle states, respectively.

FIG. 3 illustrates an example of a polarity detector structure 300 that supports efficient polarity detection with dynamic control and optimization in accordance with aspects of the present disclosure. In some examples, the polarity detector structure 300 may be implemented by aspects of the wireless communication systems 100 and/or 200. In some cases, the polarity detector structure 300 may be represented using one or more recommendation estimators as discussed above with reference to fig. 2. In some cases, the encoder at the transmitting end may identify default values for information bits K and total bits N to be used in encoding the codeword. In some examples, the codeword may be a polar codeword. In this example, N may be 256 (i.e., 2)ⁿWherein n is 8).

As shown, a wireless device (e.g., a UE) may receive encoded data via a receiver. Further, the UE may perform one or more polarity detection and decoding techniques to determine decoded bit values. For example, a decoder in the UE may determine input (e.g., unpolarized) LLRs for a bit channel of the received codeword. During decoding (e.g., SC or SCL decoding), the decoder may determine decoded LLRs based on the input LLRs and feedback bits from the SC or SCL decoding, where the decoded LLRs correspond to each polarized bit channel of the polar code. In some cases, these decoded LLRs may be referred to as bit metrics. In some cases, if an LLR is zero or a positive value, the decoder may determine that the corresponding bit is a 0 bit, and a negative LLR may correspond to a 1 bit. In some examples, the decoder may use a bit metric to determine the decoded bit values.

In some cases, due to LLR derivation dependencies, the SC decoding process may decode codewords sequentially (e.g., in order of bit channel indices). That is, because the first bit channel depends on the input LLRs and undecoded bits, each SC decoding process may first decode the bits corresponding to the first bit channel. Decoding the bits for each subsequent bit channel depends on feedback of previously decoded bits. For example, decoding bits for the second bit channel depends on feedback from decoding the first bit channel, decoding bits for the third bit channel depends on feedback from decoding the first and second bit channels, and so on.

In some cases and as shown in fig. 3, L0(256) -L8 (1) may represent LLRs at a particular stage (or layer), where L0 includes 256 channel LLRs for a codeword in the illustrated example. In this example, the 256 LLRs (i.e., unpolarized LLRs) at the channel layer (L0) may also be referred to as a set of received bit metrics. Moreover, the decoded LLRs at intermediate polarization layers (e.g., layers L1-L7) may be grouped into different LLR subsets, where the total number of decoded LLRs at any layer may not exceed 256. In some aspects, the LLRs for the intermediate polarizing layers may be polarized based on F and G operations.

In some cases, polarity encoding may be performed using one or more exclusive-or operations. In addition, the structure of the polar code may result in directionality of the XOR-operation, which means that a given codeword bit may depend only on the higher bits in decoding order.

In some aspects, the polar code may be identified based at least in part on determining whether a positive coherent combining characteristic is satisfied. In some cases, the LLRs may be used to determine whether the characteristic is satisfied. In some aspects, if the mean of the LLRs is strongly positive or negative (i.e., a larger mean), it may represent a polar code and a more reliable bit channel. In some other cases, an average value closer to zero may indicate noise due to minimum consistency of the decoded bits.

In some cases, the composition metrics may be derived based in part on the LLRs. For example, the estimator may be defined using N LLRs of an (N, k) polarity code. In some cases, polarity detector structure 300 may be based on a binary tree, where each branch in the tree may represent an F or G operation. In some examples, in fig. 3, the F operation may be shown as traversing toward the top of the page, while in fig. 3, the G operation may be shown as traversing toward the bottom of the page. In some examples, polarity detection using the estimator may include performing an F-operation until a predetermined number of information bits are encountered. As shown, the UE may perform F operation until the first information bit u is found₀Thus far, in the example shown, the first information bit u₀Corresponding to F64310. In thatIn some other cases, the UE may traverse the F-tree until an F-block with no information bits or more than one information bit is reached. In some aspects, the decoder may only need to reach the intermediate decoding layer (e.g., may not need to reach the leaf layer) based on a frozen bit distribution or a hypothetical pattern of frozen bits and information bits. For example, given a known frozen bit distribution, coherent combining may be performed on the proposed estimator F64 without traversing the leaf layer. In some cases, sF64 may be determined based on elements in vF64 (i.e., vectors of derived LLRs associated with block F64). In some cases, the elements of vF64 may provide insight as to whether a codeword is likely to be a polar codeword. For example, polar codes may satisfy the coherent combining characteristics, while Additive White Gaussian Noise (AWGN) may not satisfy the coherent combining characteristics.

Other estimators may also or alternatively be used. For example, sF32 may be used as a component estimator for detecting polar structures, where sF32 corresponds to F32 block 315, and F32 block 315 is a child node of a G node (e.g., G64) and does not include any information bits. That is, even after the first estimator for a node having one or more information bits, additional estimators may be used for other nodes having a predetermined number (e.g., zero, 1, 2, etc.) of information bits. In some aspects, using sF32 as an estimator may be different from sF64 due to feedback of information bits via G nodes. In some cases, the first information bit u₀May be feedback up to L264. The LLRs of G64 (including their composite symbols) may depend on the feedback bits. In some cases, the coherent combining properties may still be maintained (i.e., if a polar code), and the absolute values of the LLRs from vF32 may be used to determine sF32 according to the above definition. In such a case, the absolute value of sF32 may be compared to the zero mean sum.

In some other cases, opportunistic or hypothetical methods may be used. In this example, u is due to the first information bit₀Only one of the two possible bit values (i.e. 0 or 1) may be taken, so two quantities may be derived for sF32, based on which polarity detection may be performedAnd (6) measuring. Specifically, LLRs for G64 may be calculated for the first information bits being 1 and 0, and LLRs for F32 may be calculated based on the LLRs for G64. In some cases, if the two scalars calculated from different bit values are approximately zero (i.e., zero-like), the UE may determine that the likelihood of the codeword being a polarity-encoded codeword is low. Conversely, if at least one of the two scalars is strongly positive (i.e., large amplitude), the codeword may be detected as a polarity-encoded codeword.

In some cases, the F32 block may also include one information bit u₁. In this case, the second information bit u may be determined based on the LLR in F32 and the likelihood that the information bit is 1 or 0₁. That is, there may be four estimator quantities for either vF32 or sF32 that correspond to polarity encoded codewords. Alternatively, the next information bit u₁May be in block F16, as shown in fig. 3. In the example shown, block F16 may have two information bits associated with it. In such a case, the two information bits may be calculated, fed back to calculate the LLR of G32, and the LLR of F16 may be derived based on the LLR of G32. In an alternative technique, since the two information bits associated with F16 may only take 4 possible patterns (i.e., 00, 01, 10, 11), 4 estimator quantities may be determined for the 4 patterns.

Fig. 4 illustrates an example of a decoding process 400 that supports efficient polarity detection in accordance with various aspects of the disclosure. In some examples, the decoding process 400 may be implemented by aspects of the wireless communication system 100. The decoding process 400 may be performed by the base station 105, the UE115, or the device 200 as described with reference to fig. 1 and 2. The decoding process 400 may be represented by a binary tree, where each branch in the tree represents an F or G operation.

In some cases, a leaf node (not shown) may be N hard bits to be decoded sequentially, and soft information (e.g., LLRs) on the received vector may be an input at node 420-a. In the example shown, node 420-a is associated with level 1, which corresponds to F128 used for decoding of the polar code. In some cases, the soft values received from the channel and the internal switching information within the decoder may be considered LLRs. At each stage, LLR values 405 may be sent from a parent node (e.g., node 420-a) to child nodes at lower layers, while hard decision values 410 may be fed back from the child nodes to the parent node.

As shown in fig. 4, the decoding process 400 may involve intermediate decoding layers associated with the estimator. For example, the decoding process 400 shows estimators F64 and G64 (nodes 420-b and 420-c of layer 2). In some cases, the LLRs associated with the intermediate layer may pass from the parent node (e.g., node 420-a) down to the child node (e.g., node 420-b). In some cases, the LLR vectors to the left child node (i.e., vF) and to the right child node (vG) may be calculated using the following equations: f (a, b) ═ sgn (a) · sgn (b) · min (| a | | b |), and

g (a, b) ═ a + b, if F (a, b) >0,

a + b if F (a, b) < 0

Where "a" and "b" may represent components of a vector of LLRs at a given layer.

In this example, the LLRs associated with estimator F128 may be passed to F64. In some cases, when a leaf node (i.e., a node in leaf layer 425) is reached, the ith hard decision value may be set to the estimation bit u_i。

Thus, in some aspects, the LLR vector sent to the left child node may be calculated by an F operation or function, while the LLR vector directed to the right child node may be calculated by a G operation or function. In some aspects, probing the binary tree in the decoding process 400 tree may be viewed as a sequence of F and G operations.

In some cases, based on a frozen bit pattern (i.e., the first information bit u₀Position of) can be performed on the estimator without traversing the leaf level. In some examples, polarity detection using the estimator may include performing an F-operation until a predetermined number of information bits are encountered. As shown, the UE may perform F-operations until the first information bit u is located₀Until now. In some other cases, the UE may traverse the F-tree until an F-block is reached that has no information bits.

At one endIn one example, the first information bit u₀May be estimated as 0 or 1, based on which the LLR of G64 may be calculated (e.g., per hypothesis). For example, the LLRs input to nodes 420-c may be computed based on hard decision 410 feedback of an opportunity or assumption from layer 2 to layer 1. Further, LLR vector vF32 may be determined from the LLRs of G64 (e.g., from for information bit u₀Each hypothesis of (b) scalar sF32 may be determined from LLR vector vF 32. For example, the absolute values of the elements of one or more vectors vF32 may be summed to determine one or more values of sF 32. In some cases, if sF32 is strongly positive (or negative), the codeword may be determined to be a polarity encoded codeword. In some other cases, if sF32 is close to zero, it may be determined that the codeword is not a polarity encoded codeword.

As described above, scalars sFN, sGN, dFN, or dGN may be conditioned on certain patterns defined by the associated set of information bits for a block. For example, the estimator sF64 ═ Σ_i(elem_iin vF 64). For example, if the F16 block has two information bits, then dF16a and dF16b may be expressed as: dF16_ a ═ Q_even+Q_oddAnd dF16_ b ═ Q_even–Q_oddL, wherein Q_even＝∑_{i even}(elem_iin vF16) and Q_odd＝∑_{i odd}(elem_iin vF16)。

Although discussed as an estimator that does not traverse to intermediate layers of the leaf layer, one skilled in the art will understand how to implement a similar technique when traversing to the leaf layer, where the feedback represents a hard decision of the feedback bits of each list candidate of the SCL decoder implemented at the leaf layer.

In some aspects, analyzing LLRs at non-leaf levels within a binary tree for polar decoding may be used to inform P and Q modes of operation, as further described with reference to fig. 5. In some cases, taking one or more metrics of LLRs at intermediate layers may provide insight into early termination of decoding. In some aspects, early termination using the list method may rely on normalization, which may be optimized using the techniques described herein. For example, since each bit is decoded in F64, it may act differently on the calculation of LLRs in G64. In such a case, a common factor may be used to scale the LLRs. In some cases, normalization may adversely affect the result of the qualification and disqualification of the candidate path.

Fig. 5 illustrates an example of a flow chart 500 to support efficient polarity detection with dynamic control and optimization in accordance with aspects of the present disclosure. In some examples, flowchart 500 may implement aspects of wireless communication systems 100 and/or 200.

As shown, at 505-a, a decoder in a wireless device, such as a UE, may determine one or more parameters, such as RRC state (e.g., idle or connected), SNR, previous polarity detection, error cost, which may be used for dynamic control and optimization of polarity detection.

At 505-b, the decoder may determine whether polarity detection may be turned on based in part on the parameters received in 505-a. If so, the decoder may begin the pre-detection process at 510-a. In some cases, polarity detection may not be turned on, and the decoder may perform polarity decoding at 520.

In some cases, one or more LLRs (soft values) may be identified and passed at 510-b. In some cases, if polarity detection is turned on, one or more derived metrics (i.e., derived LLRs) computed or estimated from the original LLRs may be passed for polarity detection at 515-a.

In some cases, at 515-b, the operating mode (P or Q) may be selected to control polarity detection. As described previously, the P-mode may enable the polarity detector to prioritize the list of decoding candidates with ranking or via an estimated metric. In some other cases, the Q mode may enable the polarity detector to define candidates via hypothesis testing. The selection of P-mode or Q-mode may depend on a number of factors, including at least the RRC state. In some examples, both P-mode and Q-mode may be enabled, with the polarity detector prioritizing the qualifying candidates.

At 515-a, polarity detection may be performed, which may include evaluating the quality of the frozen bit components of the codeword to estimate the likelihood of whether the observed set of LLRs is a polar codeword. Further, the polarity detection may include determining a list of decoding candidates and a priority ranking of the decoding candidates.

At 520, the decoder may perform polar decoding based in part on the input received from 515-a (i.e., the list of decoding candidates, etc.) and the LLRs from 510-b.

At 525, the decoder may perform post-decoding processing based on the decoded bits of the list of hypotheses received from 520. In some cases, the post-decoding processing may include at least an error checking process (e.g., using CRC bits) and pruning of the decoding candidate paths (i.e., SCL decoder).

At 530, the decoder may determine information bits of the codeword (e.g., DCI within the codeword search space) or declare a decoding failure (i.e., invalid) based on post-decoding processing.

Fig. 6 illustrates a block diagram 600 of a device 605 that supports efficient polarity detection with dynamic control and optimization in accordance with aspects of the present disclosure. The device 605 may be an example of aspects of a UE115 or a base station 105 as described herein. The device 605 may include a receiver 610, a communication manager 615, and a transmitter 620. The device 605 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

Receiver 610 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to efficient polarity detection with dynamic control and optimization, etc.). Information may be passed to other components of device 605. The receiver 610 may be an example of aspects of the transceiver 920 or 1020 described with reference to fig. 9 and 10. Receiver 610 may utilize a single antenna or a group of antennas.

The communication manager 615 may perform the following operations: monitoring decoding candidates for a codeword, wherein the codeword corresponds to a received bit metric set and the decoding candidates correspond to a set of information bits encoded using a polar code; determining a composite detection metric for the codeword for the decoding candidates, wherein the composite detection metric is derived from a first subset of bit metrics of an intermediate polarization layer of the polar code; and determining a classification for performing a list decoding process on the codeword according to the decoding candidates based on the composite detection metric.

The communication manager 615 may also be configured to: monitoring a codeword search space comprising a set of decoding candidates associated with a polar code; determining a pattern of polarity detection for the search space, the polarity detection being based on a composite detection metric of the set of decoding candidates, wherein the composite detection metric is derived from respective subsets of bit metrics of the set of decoding candidates for at least one intermediate polarization layer of the polar code; and performing a list decoding process for at least one decoding candidate of the set of decoding candidates for the search space based on the pattern of polarity detection for the search space. The communication manager 615 may identify one or more list candidates of at least one of the set of decoding candidates from the list decoding process and may obtain the set of data bits based on an error checking process (e.g., for list candidates having a passing CRC). The communication manager 615 may be an example of aspects of the communication manager 910 or 1010 described herein.

The communication manager 615, or subcomponents thereof, may be implemented in hardware, code executed by a processor (e.g., software or firmware), or any combination thereof. If implemented in code executed by a processor, the functions of the communication manager 615, or subcomponents thereof, may be performed by a general purpose processor, a DSP, an Application Specific Integrated Circuit (ASIC), an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in this disclosure.

The communication manager 615, or subcomponents thereof, may be physically located at various locations, including being distributed such that some of the functionality is implemented by one or more physical components at different physical locations. In some examples, the communication manager 615, or subcomponents thereof, may be separate and distinct components in accordance with various aspects of the present disclosure. In some examples, the communication manager 615, or subcomponents thereof, may be combined with one or more other hardware components, including but not limited to an input/output (I/O) component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof, in accordance with various aspects of the present disclosure.

Transmitter 620 may transmit signals generated by other components of device 605. In some examples, the transmitter 620 may be collocated with the receiver 610 in a transceiver module. For example, the transmitter 620 may be an example of aspects of the transceiver 920 or 1020 described with reference to fig. 9 and 10. The transmitter 620 may utilize a single antenna or a group of antennas.

Fig. 7 illustrates a block diagram 700 of an apparatus 705 that supports efficient polarity detection with dynamic control and optimization in accordance with aspects of the present disclosure. The device 705 may be an example of aspects of the device 605, UE115, or base station 105 as described herein. The device 705 may include a receiver 710, a communication manager 715, and a transmitter 740. The device 705 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

Receiver 710 can receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to efficient polarity detection with dynamic control and optimization, etc.). Information may be passed to other components of the device 705. Receiver 710 may be an example of aspects of transceiver 920 or 1020 described with reference to fig. 9 and 10. Receiver 710 can utilize a single antenna or a group of antennas.

The communication manager 715 may be an example of aspects of the communication manager 615 as described herein. The communication manager 715 may include a decoder 720, a composite detection metrics component 725, a classification component 730, and a list decoding component 735. The communication manager 715 may be an example of aspects of the communication manager 910 or 1010 as described herein.

The decoder 720 may monitor decoding candidates for a codeword, where the codeword corresponds to the received bit metric set and the decoding candidates correspond to a set of information bits encoded using a polar code.

The composite detection metric component 725 can determine a composite detection metric for the codeword for the decoding candidates, wherein the composite detection metric is derived from a first subset of bit metrics for the intermediate polarization layer of the polar code.

Classification component 730 may determine a classification for performing a list decoding process on the codeword according to the decoding candidates based on the composite detection metric.

The decoder 720 may receive a search space that includes a set of decoding candidates associated with a polarity code.

The composite detection metric component 725 may determine a pattern of polarity detection for the search space, the polarity detection being based on a composite detection metric of the set of decoding candidates, wherein the composite detection metric is derived from a respective subset of bit metrics of the set of decoding candidates for at least one intermediate polarization layer of the polar code.

List decoding component 735 may perform a list decoding process for at least one decoding candidate in the set of decoding candidates for the search space based on a pattern of polarity detection for the search space.

Transmitter 740 may transmit signals generated by other components of device 705. In some examples, transmitter 740 may be collocated with receiver 710 in a transceiver module. For example, transmitter 740 may be an example of aspects of transceiver 920 or 1020 described with reference to fig. 9 and 10. Transmitter 740 may utilize a single antenna or a group of antennas.

Fig. 8 illustrates a block diagram 800 of a communication manager 805 that supports efficient polarity detection with dynamic control and optimization in accordance with aspects of the present disclosure. The communication manager 805 may be an example of aspects of the communication manager 615, the communication manager 715, or the communication manager 910 described herein. The communication manager 805 can include a decoder 810, a composite detection metric component 815, a classification component 820, a ranking component 825, a weighting component 830, a bit metric component 835, a list decoding component 840, a detection pattern component 845, and a define pattern component 850. Each of these modules may communicate with each other directly or indirectly (e.g., via one or more buses).

The decoder 810 may monitor decoding candidates for a codeword, where the codeword corresponds to a received bit metric set and the decoding candidates correspond to a set of information bits encoded using a polar code.

In some examples, the decoder 810 may receive a search space that includes a set of decoding candidates associated with a polarity code.

The composite detection metric component 815 may determine a composite detection metric for the codeword for the decoding candidate, where the composite detection metric is derived from a first subset of bit metrics for an intermediate polarization layer of the polar code.

In some examples, the composite detection metric component 815 may determine a pattern of polarity detection for the search space, the polarity detection based on a composite detection metric of the set of decoding candidates, wherein the composite detection metric is derived from a respective subset of bit metrics of the set of decoding candidates for the at least one intermediate polarization layer of the polar code.

Classification component 820 can determine a classification for performing a list decoding process on the codeword according to the decoding candidates based on the composite detection metric.

In some examples, classification component 820 may determine to refrain from the list decoding process for the decoding candidate.

In some examples, classification component 820 may compare the composite detection metric to a threshold, wherein the threshold is based on a connection status, a signal metric, a device status, a detection history, a communication protocol, or a combination thereof.

List decoding component 840 can perform a list decoding process for at least one decoding candidate in the set of decoding candidates for the search space based on a pattern of polarity detection for the search space.

In some cases, performing the list decoding process includes: the list decoding process is performed on the decoding candidate set in an order determined based on the polarity detection.

In some cases, performing the list decoding process includes: a list decoding process is performed on a subset of the set of decoding candidates determined based on the polarity detection.

Ranking component 825 may determine a ranking for performing a list decoding process on the codeword according to decoding candidates relative to other decoding candidates of the set of decoding candidates for the codeword search space.

The weighting component 830 can apply a weighting vector to the first subset of bit metrics. In some examples, weighting component 830 may also apply a second weighting vector to a second subset of bit metrics associated with a second intermediate polarization layer of the polar code.

In some examples, weighting component 830 may apply one or more weighting vectors to the first subset of bit metrics to obtain one or more intermediate composite metrics.

Bit metric component 835 may determine a derived bit metric based on a bit metric quantum set and a weighting pattern determined based on a number of information bits in a subset of leaf nodes corresponding to the bit metric subset. In some cases, the bit metric component 835 may apply one or more activation functions to combine the weighted first bit metric quantum set and the weighted second bit metric subset. In some other cases, bit metric component 835 may apply one or more activation functions to combine one or more intermediate metrics or derived bit metrics to obtain a composite detection metric. In some examples, the activation function may include a non-linear transformation.

In some cases, the subset of bit metrics is determined based on a single parity operation or a repeat operation from bit metrics at a polarization layer feeding an intermediate polarization layer.

In some cases, the subset of bit metrics corresponds to log-likelihood ratios (LLRs) for a corresponding subset of bit channels of the polar code.

The detect mode component 845 can determine a mode for polarity detection. In some cases, determining the mode for polarity detection includes: a prioritization scheme for polarity detection is selected.

In some cases, determining a mode for polarity detection is based on a connection state, a signal metric, a device state, a detection history, a communication protocol, or a combination thereof.

The defined mode component 850 can select a defined mode for polarity detection.

Fig. 9 illustrates a diagram of a system 900 including a device 905 that supports efficient polarity detection with dynamic control and optimization, in accordance with aspects of the present disclosure. The device 905 may be an example of a device 605, device 705, or UE115 or include components of the device 605, device 705, or UE115 as described herein. The device 905 may include components for two-way voice and data communications, including components for sending and receiving communications, including a communication manager 910, a transceiver 920, an antenna 925, a memory 930, a processor 940, and an I/O controller 950. These components may be in electronic communication via one or more buses, such as bus 955.

The communication manager 910 may perform the following operations: monitoring decoding candidates for a codeword, wherein the codeword corresponds to a received bit metric set and the decoding candidates correspond to a set of information bits encoded using a polar code; determining a composite detection metric for the codeword for the decoding candidates, wherein the composite detection metric is derived from a subset of bit metrics of an intermediate polarization layer of the polar code; and determining a classification for performing a list decoding process on the codeword according to the decoding candidates based on the composite detection metric.

The communication manager 910 may also perform the following operations: receiving a search space comprising a set of decoding candidates associated with a polar code; determining a pattern of polarity detection for the search space, the polarity detection being based on a composite detection metric of the set of decoding candidates, wherein the composite detection metric is derived from respective subsets of bit metrics of the set of decoding candidates for at least one intermediate polarization layer of the polar code; and performing a list decoding process for at least one decoding candidate of the set of decoding candidates for the search space based on the pattern of polarity detection for the search space.

The transceiver 920 may communicate bi-directionally via one or more antennas, wired or wireless links as described above. For example, the transceiver 920 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 920 may also include a modem to modulate packets and provide the modulated packets to the antennas for transmission, as well as demodulate packets received from the antennas.

In some cases, the wireless device may include a single antenna 925. However, in some cases, the device may have more than one antenna 925 capable of simultaneously sending or receiving multiple wireless transmissions.

The memory 930 may include RAM, ROM, or a combination thereof. The memory 930 may store computer-readable code 935, which computer-readable code 935 comprises instructions that, when executed by a processor (e.g., the processor 940), cause the apparatus to perform various functions described herein. In some cases, memory 930 may contain, among other things, a BIOS that may control basic hardware or software operations, such as interaction with peripheral components or devices.

Processor 940 may include intelligent hardware devices (e.g., general-purpose processors, DSPs, CPUs, microcontrollers, ASICs, FPGAs, programmable logic devices, discrete gate or transistor logic components, discrete hardware components, or any combinations thereof). In some cases, processor 940 may be configured to operate the memory array using a memory controller. In other cases, the memory controller may be integrated into processor 940. Processor 940 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 930) to cause device 905 to perform various functions (e.g., to support functions or tasks with efficient polarity detection for dynamic control and optimization).

The I/O controller 950 may manage input and output signals for the device 905. The I/O controller 950 may also manage peripheral devices that are not integrated into the device 905. In some cases, I/O controller 950 may represent a physical connection or port to an external peripheral device. In some cases, I/O controller 950 may utilize a processor such as Such as an operating system or another known operating system. In other cases, I/O controller 950 may represent or interact with a modem, keyboard, mouse, touch screen, or similar device. In some cases, I/O controller 950 may be implemented as part of a processor. In some cases, a user may interact with device 905 via I/O controller 950 or via hardware components controlled by I/O controller 950.

Code 935 may include instructions to implement aspects of the disclosure, including instructions to support wireless communications. Code 935 may be stored in a non-transitory computer-readable medium (e.g., system memory or other type of memory). In some cases, code 935 may not be directly executable by processor 940, but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

Fig. 10 shows a diagram of a system 1000 including a device 1005 that supports efficient polarity detection with dynamic control and optimization, in accordance with aspects of the present disclosure. Device 1005 may be an example of device 605, device 705, or base station 105 or include components of device 605, device 705, or base station 105 as described herein. The device 1005 may include components for two-way voice and data communications, including components for sending and receiving communications, including a communication manager 1010, a network communication manager 1015, a transceiver 1020, an antenna 1025, a memory 1030, a processor 1040, and an inter-station communication manager 1045. These components may be in electronic communication via one or more buses, such as bus 1055.

The communication manager 1010 may perform the following operations: monitoring decoding candidates for a codeword, wherein the codeword corresponds to a received bit metric set and the decoding candidates correspond to a set of information bits encoded using a polar code; determining a composite detection metric for the codeword for the decoding candidates, wherein the composite detection metric is derived from a subset of bit metrics of an intermediate polarization layer of the polar code; and determining a classification for performing a list decoding process on the codeword according to the decoding candidates based on the composite detection metric.

The communication manager 1010 may also perform the following operations: receiving a search space comprising a set of decoding candidates associated with a polar code; determining a pattern of polarity detection for the search space, the polarity detection being based on a composite detection metric of the set of decoding candidates, wherein the composite detection metric is derived from respective subsets of bit metrics of the set of decoding candidates for at least one intermediate polarization layer of the polar code; and performing a list decoding process for at least one decoding candidate of the set of decoding candidates for the search space based on the pattern of polarity detection for the search space.

The network communication manager 1015 may manage communication with the core network (e.g., via one or more wired backhaul links). For example, the network communication manager 1015 may manage the transmission of data communications for client devices (e.g., one or more UEs 115).

The transceiver 1020 may communicate bi-directionally via one or more antennas, wired or wireless links as described above. For example, transceiver 1020 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 1020 may also include a modem to modulate packets and provide the modulated packets to the antennas for transmission, as well as demodulate packets received from the antennas.

In some cases, a wireless device may include a single antenna 1025. However, in some cases, the device may have more than one antenna 1025 that can send or receive multiple wireless transmissions simultaneously.

Memory 1030 may include RAM, ROM, or a combination thereof. The memory 1030 may store computer readable code 1035, the computer readable code 1035 comprising instructions that, when executed by a processor (e.g., the processor 1040), cause the apparatus to perform various functions described herein. In some cases, memory 1030 may contain, among other things, a BIOS that may control basic hardware or software operations, such as interaction with peripheral components or devices.

Processor 1040 may include intelligent hardware devices (e.g., a general purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, processor 1040 may be configured to operate the memory array using a memory controller. In other cases, a memory controller may be integrated into processor 1040. The processor 1040 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 1030) to cause the device 1005 to perform various functions (e.g., to support functions or tasks with efficient polarity detection with dynamic control and optimization).

The inter-station communication manager 1045 may manage communications with other base stations 105 and may include a controller or scheduler for controlling communications with UEs 115 in cooperation with other base stations 105. For example, the inter-station communication manager 1045 may coordinate scheduling for transmissions to the UEs 115 to implement various interference mitigation techniques, such as beamforming or joint transmission. In some examples, the inter-station communication manager 1045 may provide an X2 interface within LTE/LTE-a wireless communication network technology to provide communication between base stations 105.

Code 1035 may include instructions for implementing aspects of the disclosure, including instructions for supporting wireless communications. Code 1035 may be stored in a non-transitory computer-readable medium, such as a system memory or other type of memory. In some cases, code 1035 may not be directly executable by processor 1040, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

Fig. 11 shows a flow diagram illustrating a method 1100 of supporting efficient polarity detection with dynamic control and optimization in accordance with aspects of the present disclosure. The operations of method 1100 may be implemented by a UE115 or a base station 105 or components thereof as described herein. For example, the operations of method 1100 may be performed by a communications manager as described with reference to fig. 6-10. In some examples, a UE or base station may execute a set of instructions to control the functional units of the UE or base station to perform the functions described below. Additionally or alternatively, the UE or base station may use dedicated hardware to perform aspects of the functions described below.

At 1105, the UE or base station may monitor decoding candidates for a codeword, where the codeword corresponds to a received set of bit metrics and the decoding candidates correspond to a set of information bits encoded using a polar code. For example, a UE or base station may monitor multiple blind PDCCH decoding hypotheses (e.g., decoding candidates for a codeword search space) for a duration such as a time slot. The operations of 1105 may be performed in accordance with the methods described herein. In some examples, aspects of the operations of 1105 may be performed by a decoder as described with reference to fig. 6-10.

At 1110, the UE or base station may determine a composite detection metric for the codeword for the decoding candidate, wherein the composite detection metric is derived from a first subset of bit metrics for a first intermediate polarization layer of the polar code. In some cases, determining the composite detection metric may include: the weighting vector is applied to the first subset of bit metrics. Further, the UE or base station may apply a second weighting vector to a second subset of bit metrics associated with a second intermediate polarization layer of the polar code and apply one or more activation functions to combine the weighted first subset of bit metrics and the weighted second subset of bit metrics.

In some other cases, determining the composite detection metric may include: applying one or more weighting vectors to the first subset of bit metrics to obtain one or more intermediate composite metrics; and applying one or more activation functions to combine the one or more intermediate metrics to obtain a composite detection metric. The operations of 1110 may be performed according to methods described herein. In some examples, aspects of the operations of 1110 may be performed by one or more of a composite detection metric component, a weighting component, or a bit metric component as described with reference to fig. 6-10.

At 1115, the UE or base station may determine a classification for performing a list decoding process on the codeword according to the decoding candidates based on the composite detection metric. In some cases, determining a classification for performing the list decoding process may include: it is determined to suppress the list decoding process for the decoding candidate. Additionally or alternatively, the operations of 1115 may further include: a rank for performing a list decoding process on the codeword according to the decoding candidates is determined relative to other decoding candidates of the plurality of decoding candidates for the codeword search space. The operations of 1115 may be performed according to methods described herein. In some examples, aspects of the operation of 1115 may be performed by a classification component as described with reference to fig. 6-10.

Fig. 12 shows a flow diagram illustrating a method 1200 of supporting efficient polarity detection with dynamic control and optimization in accordance with aspects of the present disclosure. The operations of method 1200 may be implemented by a UE115 or a base station 105 or components thereof as described herein. For example, the operations of method 1200 may be performed by a communications manager as described with reference to fig. 6-10. In some examples, a UE or base station may execute a set of instructions to control the functional units of the UE or base station to perform the functions described below. Additionally or alternatively, the UE or base station may use dedicated hardware to perform aspects of the functions described below.

At 1205, the UE or base station may receive a search space including a set of decoding candidates associated with a polar code. For example, a UE or base station may monitor multiple blind PDCCH decoding hypotheses (e.g., decoding candidates for a codeword search space) for a duration such as a slot, and may receive the search space based on the monitoring. The operations of 1205 may be performed according to methods described herein. In some examples, aspects of the operations of 1205 may be performed by a decoder as described with reference to fig. 6-10.

At 1210, a UE or a base station may determine a pattern for polarity detection for a search space, the polarity detection based on a composite detection metric for a set of decoding candidates, wherein the composite detection metric is derived from a respective subset of bit metrics for the set of decoding candidates for at least one intermediate polarization layer of a polar code. In some cases, determining the mode for polarity detection may include: one of a prioritized or defined pattern for polarity detection is selected. In some cases, determining a mode for polarity detection may be based on connection status, signal metrics, device status, detection history, communication protocol, or a combination thereof. The operations of 1210 may be performed according to methods described herein. In some examples, aspects of the operations of 1210 may be performed by one or more of a composite detection metrics component, a defined pattern component, or a detection pattern component as described with reference to fig. 6-10.

At 1215, the UE or base station may perform a list decoding process for at least one decoding candidate in the set of decoding candidates for the search space based on the mode of polarity detection for the search space. In some cases and based in part on the determined mode for polarity detection (i.e., prioritization or qualification), the list decoding process may be performed on a plurality of decoding candidates in an order determined based at least in part on polarity detection, or on a subset of the plurality of decoding candidates determined based at least in part on polarity detection. The operations of 1215 may be performed in accordance with the methods described herein. In some examples, aspects of the operations of 1215 may be performed by a list decoding component as described with reference to fig. 6-10.

It should be noted that the above described methods describe possible implementations and that the operations and steps may be rearranged or otherwise modified and that other implementations are possible. Further, aspects from two or more methods may be combined.

The techniques described herein may be used for various wireless communication systems such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), single carrier frequency division multiple access (SC-FDMA), and other systems. A CDMA system may implement a radio technology such as CDMA2000, Universal Terrestrial Radio Access (UTRA), and so on. CDMA2000 covers IS-2000, IS-95 and IS-856 standards. The IS-2000 version may be generally referred to as CDMA 20001X, 1X, etc. IS-856(TIA-856) IS commonly referred to as CDMA 20001 xEV-DO, High Rate Packet Data (HRPD), etc. UTRA includes wideband CDMA (wcdma) and other variants of CDMA. TDMA systems may implement radio technologies such as global system for mobile communications (GSM).

The OFDMA system may implement radio technologies such as Ultra Mobile Broadband (UMB), evolved UTRA (E-UTRA), Institute of Electrical and Electronics Engineers (IEEE)802.11(Wi-Fi), IEEE 802.16(WiMAX), IEEE 802.20, flash-OFDM, etc. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS). LTE, LTE-A and LTE-A specialties are releases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE-A, LTE-A specialty, NR, and GSM are described in documents from an organization named "3 rd Generation partnership project" (3 GPP). CDMA2000 and UMB are described in documents from an organization named "3 rd generation partnership project 2" (3GPP 2). The techniques described herein may be used for the above-mentioned systems and radio technologies, as well as other systems and radio technologies. Although aspects of the LTE, LTE-A, LTE-a specialty, or NR system may be described for purposes of example, and LTE, LTE-A, LTE-a specialty, or NR terminology may be used in much of the description, the techniques described herein may be applicable to ranges outside of LTE, LTE-A, LTE-a specialty, or NR applications.

A macro cell typically covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs 115 with service subscriptions with the network provider. A small cell may be associated with a lower power base station 105 than a macro cell, and the small cell may operate in the same or different (e.g., licensed, unlicensed, etc.) frequency band as the macro cell. According to various examples, the small cells may include pico cells, femto cells, and micro cells. For example, a pico cell may cover a small geographic area and may allow unrestricted access by UEs 115 with service subscriptions with the network provider. A femto cell may also cover a small geographic area (e.g., a residence) and may provide restricted access by UEs 115 having an association with the femto cell (e.g., UEs 115 in a Closed Subscriber Group (CSG), UEs 115 for users in the residence, etc.). An eNB for a macro cell may be referred to as a macro eNB. An eNB for a small cell may be referred to as a small cell eNB, pico eNB, femto eNB, or home eNB. An eNB may support one or more (e.g., two, three, four, etc.) cells and may also support communication using one or more component carriers.

The wireless communication system 100 or system described herein may support synchronous or asynchronous operation. For synchronous operation, the base stations 105 may have similar frame timing, and transmissions from different base stations 105 may be approximately aligned in time. For asynchronous operation, the base stations 105 may have different frame timings, and transmissions from different base stations 105 may not be aligned in time. The techniques described herein may be used for synchronous or asynchronous operations.

The information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

The various illustrative blocks and modules described in connection with the disclosure herein may be implemented or performed with a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other Programmable Logic Device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and the appended claims. For example, due to the nature of software, the functions described above may be implemented using software executed by a processor, hardware, firmware, hard wiring, or a combination of any of these. Features implementing functions may also be physically located at various locations, including being distributed such that portions of functions are implemented at different physical locations.

Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. Non-transitory storage media may be any available media that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, non-transitory computer-readable media can comprise Random Access Memory (RAM), Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), flash memory, Compact Disc (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Further, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes CD, laser disc, optical disc, Digital Versatile Disc (DVD), floppy disk and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

As used herein (including in the claims), an "or" as used in a list of items (e.g., a list of items ending with a phrase such as "at least one of" or "one or more of") indicates an inclusive list such that, for example, a list of at least one of A, B or C means a or B or C or AB or AC or BC or ABC (i.e., a and B and C). Further, as used herein, the phrase "based on" should not be construed as a reference to a closed set of conditions. For example, an exemplary step described as "based on condition a" may be based on both condition a and condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "based at least in part on" is interpreted.

In the drawings, similar components or features may have the same reference numerals. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If only the first reference label is used in the specification, the description applies to any one of the similar components having the same first reference label irrespective of the second or other subsequent reference label.

The description set forth herein in connection with the appended drawings describes example configurations and is not intended to represent all examples that may be implemented or within the scope of the claims. The term "exemplary" as used herein means "serving as an example, instance, or illustration," rather than "preferred" or "advantageous over other examples. The detailed description includes specific details for the purpose of providing an understanding of the described technology. However, the techniques may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

The description herein is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the present disclosure is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.