阅读说明：本技术 用于生成信道状态信息报告的方法和装置 (Method and apparatus for generating channel state information report ) 是由 艾哈迈德·欣迪 泰勒·布朗 乌达·米塔尔 于 2020-03-30 设计创作，主要内容包括：本发明提供了一种方法和装置,用于生成具有与层集对应的信息的信道状态信息报告。所述方法包括接收(1202)从网络传输的参考信号集以及识别(1204)波束集。获得(1206)振幅和相位系数矢量,其中,每对所述振幅和相位系数矢量都与每个层中的波束集中的波束对应。将所述层划分(1208)成层组集。为每个层组生成(1210)波束位图矢量。基于所述波束位图矢量,为所选波束集中的每一个生成(1212)系数位图矢量,所述系数位图矢量指示具有非零振幅值的系数。将所述信道状态信息报告传输(1214)给所述网络,所述信道状态信息报告包括至少所述波束位图矢量和所述系数位图矢量。(The present invention provides a method and apparatus for generating a channel state information report having information corresponding to a layer set. The method includes receiving (1202) a set of reference signals transmitted from a network and identifying (1204) a set of beams. Obtaining (1206) amplitude and phase coefficient vectors, wherein each pair of the amplitude and phase coefficient vectors corresponds to a beam of a set of beams in each layer. The layers are partitioned (1208) into a set of groups. A beam bitmap vector is generated (1210) for each group of layers. Generating (1212), for each of the selected beam sets, a coefficient bitmap vector based on the beam bitmap vectors, the coefficient bitmap vector indicating coefficients having non-zero amplitude values. Transmitting (1214) the channel state information report to the network, the channel state information report including at least the beam bitmap vector and the coefficient bitmap vector.)

1. A method in a user equipment for generating a channel state information report having information corresponding to a layer set, the method comprising:

receiving a set of reference signals transmitted from a network comprising at least one base station;

identifying a set of beams based on the set of reference signals;

obtaining a pair of amplitude and phase coefficient vectors by transforming the received reference signal set, wherein each pair of the amplitude and phase coefficient vectors corresponds to a beam in a set of beams in each of the set of layers;

dividing layers from the set of layers into a set of groups;

generating a beam bitmap vector for each group of layers, the beam bitmap vector indicating a subset of the selected set of beams in the group of layers;

generating a coefficient bitmap vector for each of the selected set of beams in each layer based on the beam bitmap vectors, the coefficient bitmap vector indicating coefficients having a non-zero amplitude value; and

transmitting the channel state information report to the network, the channel state information report including at least the beam bitmap vector and the coefficient bitmap vector.

2. The method of claim 1, wherein a beam bitmap vector for each layer group indicates a beam selected by at least one of the layers in the layer group.

3. The method of claim 1, wherein the channel state information report is divided into at least two parts.

4. The method of claim 3, wherein the beam bitmap vector for each layer group is reported in a preselected portion of at least two portions of the channel state information report, and the coefficient bitmap vector for each layer is reported in a portion of the channel state information report following the preselected portion.

5. The method of claim 3, wherein an indication of a sum of bases across a subset of selected beam sets of groups of layers is reported in a preselected portion of at least two portions of the channel state information report, and the beam bitmap vector corresponding to each group of layers and the coefficient bitmap vector corresponding to each layer are reported in a portion of the channel state information report following the preselected portion.

6. The method of claim 5, wherein the indication of the sum of reported cardinalities in a preselected portion of the at least two portions of the channel state information report represents a composite value of the sum of selected beams for each group of layers.

7. The method of claim 3, wherein an entry in the beam bitmap vector has a particular binary value if the corresponding beam belongs to the beam subset vector, and an entry in the beam bitmap vector has a complementary binary value if the corresponding beam does not belong to the beam subset vector, the complementary binary value being complementary to the particular binary value.

8. The method of claim 7, wherein element-by-element functions of beam bitmap vectors of two or more layer groups are reported in a preselected portion of at least two portions of the channel state information report, and the coefficient bitmap vector and beam bitmap vector for each layer are reported in a portion of the channel state information report following the preselected portion.

9. The method of claim 8, wherein additional indicators are reported in a preselected portion of the at least two portions of the channel state information report reflecting a sum of the selected beams for each subset of the group of layers, the subset including less than all of the group of layers.

10. The method of claim 1, wherein the length of the beam bitmap vector for each group of layers is the number of beams selected in each polarization.

11. A user equipment for generating a channel state information report having information corresponding to a layer set, the user equipment comprising:

a transceiver that receives a set of reference signals transmitted from a network comprising at least one base station; and

a controller that identifies a set of beams based on the set of reference signals, obtains a pair of amplitude and phase coefficient vectors by transforming the received set of reference signals, wherein each pair of the amplitude and phase coefficient vectors corresponds to a beam in a set of beams in each of the set of layers, divides the layers from the set of layers into a set of groups, generates a beam bitmap vector for each group of layers, the beam bitmap vector indicating a subset of selected sets of beams in the group of layers, and generates a coefficient bitmap vector for each beam in the selected set of beams in each layer based on the beam bitmap vector, the coefficient bitmap vector indicating coefficients having a non-zero amplitude value;

wherein the transceiver further transmits the channel state information report to the network, the channel state information report including at least the beam bitmap vector and the coefficient bitmap vector.

12. The user equipment of claim 11, wherein a beam bitmap vector for each group of layers indicates a beam selected by at least one of the layers in the group of layers.

13. The user equipment of claim 11, wherein the channel state information report is divided into at least two parts.

14. The user equipment of claim 13, wherein the beam bitmap vector for each layer group is reported in a preselected portion of at least two portions of the channel state information report, and the coefficient bitmap vector for each layer is reported in a portion of the channel state information report following the preselected portion.

15. The user equipment of claim 13, wherein an indication of a sum of bases across a subset of selected beam sets of groups of layers is reported in a preselected portion of at least two portions of the channel state information report, and the beam bitmap vector corresponding to each group of layers and the coefficient bitmap vector corresponding to each layer are reported in a portion of the channel state information report following the preselected portion.

16. The user equipment of claim 15, wherein the indication of the sum of bases reported in a preselected portion of the at least two portions of the channel state information report represents a composite value of the sum of selected beams for each group of layers.

17. The user equipment of claim 13, wherein an entry in the beam bitmap vector has a particular binary value if the corresponding beam belongs to the beam subset vector, and an entry in the beam bitmap vector has a complementary binary value if the corresponding beam does not belong to the beam subset vector, the complementary binary value being complementary to the particular binary value.

18. The user equipment of claim 17, wherein element-by-element functions of beam bitmap vectors of two or more layer groups are reported in a preselected portion of at least two portions of the channel state information report, and the coefficient bitmap vector and beam bitmap vector for each layer are reported in a portion of the channel state information report following the preselected portion.

19. The user equipment of claim 18, wherein additional indicators are reported in a preselected portion of the at least two portions of the channel state information report reflecting a sum of the selected beams for each subset of the group of layers, the subset including less than all of the group of layers.

20. The user equipment of claim 11, wherein a length of a beam bitmap vector for each group of layers is a number of beams selected in each polarization.

Technical Field

The present disclosure relates to a method and apparatus related to generating a channel state information report, including generating a channel state information report having information corresponding to a set of layers, wherein a beam bitmap vector for a set of layers indicates a subset of selected beam sets for the set of layers.

Background

Currently, user equipment, such as wireless communication devices, communicate with other communication devices using wireless signals, such as in a network environment that may include one or more cells in which various communication connections with the network and other devices operating within the network may be supported. A network environment typically involves one or more sets of standards, each set of standards defining aspects of any communication connections made when the respective standard is used within the network environment. Examples of developing and/or existing standards include new radio access technology (NR), Long Term Evolution (LTE), Universal Mobile Telecommunications Service (UMTS), global system for mobile communications (GSM), and/or Enhanced Data GSM Environment (EDGE).

To enhance system performance, recent standards have investigated different forms of spatial diversity, including different forms of multiple-input multiple-output (MIMO) systems, which involve the use of multiple antennas at each of the source and destination of the wireless communication to multiply the capacity of the radio link by using multipath propagation. Such systems make it more and more possible to transmit and receive more than one data signal simultaneously using the same radio channel.

As part of supporting MIMO communications, the user equipment may use a codebook of channel state information, which helps define the properties of the employed beams for supporting a particular data connection. Higher level codebooks may sometimes be used to enhance system performance, but typically at the cost of increasing the amount of feedback overhead.

In at least some wireless communication systems, Channel State Information (CSI) feedback is used to report current channel conditions. This may be increasingly useful in Frequency Division Duplex (FDD) and Frequency Division Multiple Access (FDMA) systems where the Downlink (DL) and Uplink (UL) channels are not reciprocal. For multi-user (MU) -MIMO and spatial multiplexing, a receiving device, such as a User Equipment (UE), may need to report channel conditions for multiple channels or beams. Thus, in MU-MIMO and spatial multiplexing systems, much of the overhead may be dedicated to CSI reporting.

The present inventors have recognized that improved methods of efficiently encoding channel state information reports, and apparatus and systems performing the functions of these methods, may be beneficial. The inventors have further recognized that one such method may include communicating with a network using spatial multiplexing, the network including one or more base stations. Here, multiple transmission layers may be transmitted at a time, each transmission layer including multiple beams, which may be arranged in one or more layer groups. The beam bitmap vector for each group of layers may indicate a subset of the selected set of beams having coefficient bitmap vectors included as part of a channel state information report transmitted to the network.

Disclosure of Invention

A method in a user equipment for generating a channel state information report having information corresponding to a layer set is provided. The method includes receiving a set of reference signals transmitted from a network including at least one base station. A set of beams is identified based on a set of reference signals. A pair of amplitude and phase coefficient vectors is obtained by transforming the received reference signal set, wherein each pair of amplitude and phase coefficient vectors corresponds to a beam in a set of beams in each of the set of layers. The layers from the set of layers are partitioned into a set of groups. A beam bitmap vector is generated for each group of layers, the beam bitmap vector indicating a subset of the selected set of beams in the group of layers. Based on the beam bitmap vector, a coefficient bitmap vector is generated for each beam in the selected beam set in each layer, the coefficient bitmap vector indicating coefficients having non-zero amplitude values. Transmitting a channel state information report to the network, the channel state information report including at least a beam bitmap vector and a coefficient bitmap vector.

According to another possible embodiment, a user equipment is provided for generating a channel state information report having information corresponding to a layer set. The user equipment includes a transceiver that receives a set of reference signals transmitted from a network that includes at least one base station. The user equipment further includes a controller that identifies a beam set based on the reference signal set and obtains a pair of amplitude and phase coefficient vectors by transforming the received reference signal set, wherein each pair of amplitude and phase coefficient vectors corresponds to a beam in the beam set in each of the layers of the layer set. The controller further divides the layers from the set of layers into a set of layers, generates a beam bitmap vector for each layer group, the beam bitmap vector indicating a subset of the selected set of beams within the layer group, and generates a coefficient bitmap vector for each beam in the selected set of beams in each layer based on the beam bitmap vector, the coefficient bitmap vector indicating coefficients having non-zero amplitude values. The transceiver further transmits a channel state information report to the network, the channel state information report including at least the beam bitmap vector and the coefficient bitmap vector.

According to a further possible embodiment, a method in a network comprising at least one base station is provided for receiving a generated channel state information report with information corresponding to a layer set from a user equipment. The method includes transmitting a set of reference signals transmitted to a user equipment. A set of beams is identified based on a set of reference signals. A pair of amplitude and phase coefficient vectors is obtained by transforming the received reference signal set, wherein each pair of amplitude and phase coefficient vectors corresponds to a beam in a set of beams in each of the set of layers. The layers from the set of layers are partitioned into a set of groups. A beam bitmap vector is generated for each group of layers, the beam bitmap vector indicating a subset of the selected set of beams in the group of layers. Based on the beam bitmap vector, a coefficient bitmap vector is generated for each beam in the selected beam set in each layer, the coefficient bitmap vector indicating coefficients having non-zero amplitude values. A channel state information report is received from a user equipment, the channel state information report including at least a beam bitmap vector and a coefficient bitmap vector.

According to yet another possible embodiment, a network is provided that includes at least one base station for receiving a generated channel state information report having information corresponding to at least one layer. The network includes at least one transceiver that transmits a set of reference signals transmitted to the user equipment. A set of beams is identified based on a set of reference signals. A pair of amplitude and phase coefficient vectors is obtained by transforming the received reference signal set, wherein each pair of amplitude and phase coefficient vectors corresponds to a beam in a set of beams in each of the set of layers. The layers from the set of layers are partitioned into a set of groups. A beam bitmap vector is generated for each group of layers, the beam bitmap vector indicating a subset of the selected set of beams in the group of layers. Based on the beam bitmap vector, a coefficient bitmap vector is generated for each beam in the selected beam set in each layer, the coefficient bitmap vector indicating coefficients having non-zero amplitude values. The at least one transceiver further receives a channel state information report from the user equipment, the channel state information report comprising at least the beam bitmap vector and the coefficient bitmap vector.

These and other features and advantages of the present application may be seen from the following description of one or more preferred embodiments, taken in conjunction with the accompanying drawings.

Drawings

A more particular description of the embodiments briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only some embodiments and are not therefore to be considered to be limiting of its scope, the embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

FIG. 1 is an example block diagram of a system in accordance with possible embodiments;

FIG. 2 is an example of a bitmap schematic of size 2L M, where '×' corresponds to the position of the non-zero coefficients of a given layer;

fig. 3 is an example of a bitmap schematic of size 2L, where '×' indicates the position of a beam utilized by a given group of layers;

fig. 4-6 are bit map diagrams identifying beams utilized by a pair of layer groups and composite bit map diagrams representing a plurality of layer groups, the composite bit map diagrams formed using an exclusive or operation, according to a first example;

fig. 7-9 are bit map diagrams identifying beams utilized by a pair of layer groups and composite bit map diagrams representing a plurality of layer groups, the composite bit map diagrams formed using an exclusive or operation, according to a second example;

FIGS. 10A and 10B are tables comparing schemes across layer groups for a case where any beam of each layer group has a fixed frequency domain base size after frequency compression;

FIG. 11 is a table comparing schemes across groups of layers for a case where any beam of each group of layers has unequal frequency domain base sizes after frequency compression, where the frequency domain base size of group 2 is less than (or equal to) the frequency domain base size of group 1;

fig. 12 is a flow diagram in a user equipment for generating a channel state information report with information corresponding to a layer set;

FIG. 13 is a flow diagram of a method in a network for generating a channel state information report having information corresponding to a layer set; and

fig. 14 is an example block diagram of an apparatus according to a possible embodiment.

Detailed Description

While the present disclosure is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment with the understanding that the present disclosure is not to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiment illustrated.

Embodiments provide a method and apparatus for generating a channel state information report including generating a channel state information report having information corresponding to a layer set.

Fig. 1 is an example block diagram of a system 100 according to a possible embodiment. System 100 may include a User Equipment (UE)110, at least one network entity 120 and 125, such as a base station, and a network 130. The UE 110 may be a wireless wide area network device, a user equipment, a wireless terminal, a portable wireless communication device, a smartphone, a cellular phone, a flip phone, a personal digital assistant, a personal computer, a selective call receiver, an internet of things (IoT) device, a tablet computer, a laptop computer, or any other user equipment capable of sending and receiving communication signals over a wireless network. At least one of the network entities 120 and 125 may be a wireless wide area network base station, may be a NodeB, may be an enhanced NodeB (enb), may be a new radio NodeB (gnb) (such as a 5G NodeB), may be an unlicensed network base station, may be an access point, may be a base station controller, may be a network controller, may be a transmission/reception point (TRP), may be network entities of different types from each other and/or may be any other network entity that may provide wireless access between a UE and a network.

Network 130 may include any type of network capable of sending and receiving wireless communication signals. For example, the network 130 may include a wireless communication network, a cellular telephone network, a Time Division Multiple Access (TDMA) -based network, a Code Division Multiple Access (CDMA) -based network, an Orthogonal Frequency Division Multiple Access (OFDMA) -based network, a Long Term Evolution (LTE) network, a third generation partnership project (3GPP) -based network, a satellite communication network, a high-altitude platform network, the internet, and/or other communication networks.

In operation, UE 110 may communicate with network 130 through at least one network entity 120. For example, a UE may transmit and receive control signals on a control channel and user data signals on a data channel.

In 3GPP New Radio (NR) systems, type-1 and type-II codebook based Channel State Information (CSI) feedback has been employed to support advanced MIMO transmission. Both types of codebooks are constructed from two-dimensional Discrete Fourier Transform (DFT) based beam grids and enable CSI feedback for beam selection and Phase Shift Keying (PSK) based in-phase combining between the two polarizations. The type-I codebook is used for standard resolution CSI feedback, while the type-II codebook is used for high resolution CSI feedback. Thus, it is contemplated that more accurate CSI may be obtained from type-II codebook based CSI feedback so that the network may employ enhanced precoded MIMO transmissions.

A type-II codebook is described that handles up to two MIMO layers per transmission, taking into account the large CSI feedback overhead typically associated with each layer. Extending the type-II codebook to include more than two layers may result in a large overhead in processing the transmission.

Many techniques have been proposed to reduce the CSI feedback overhead of type-II codebooks for up to 2-level transmissions. These techniques differ in nature from spatial compression, frequency compression, and depuncture coefficients having relatively small amplitudes.

Suppose a gNB is equipped with a two-dimensional (2D) antenna array having N placed horizontally and vertically each polarization₁、N₂Antenna port, and communication takes place at N₃A Precoding Matrix Indicator (PMI) subband may include a set of resource blocks, each resource block having a set of subcarriers. To reduce Uplink (UL) feedback overhead, Discrete Fourier Transform (DFT) -based CSI compression in the spatial domain is applied to L beams per polarization, where L < N₁N₂. Similarly, additional compression is applied in the frequency domain, where each beam of the frequency domain precoding vector is transformed to the delay domain using an inverse DFT matrix, and the magnitude and phase values of a subset of the delay domain coefficients are selected and fed back to the gNB as part of the CSI report. 2N per layer r₁N₂×N₃The codebooks all take the form

Wherein, W₁Is 2N with two identical diagonal blocks₁N₂X 2L block diagonal matrix (L < N)₁N₂) That is to say that,

and B is N₁N₂The xl matrix, the columns of which are drawn by the 2D oversampled DFT matrix, is shown below.

Wherein, the upper label^TRepresenting a matrix transpose operation. Note that for the 2D DFT matrix, assume O₁、O₂The oversampling factor, matrix B, is plotted from the 2D DFT matrix. Note that W₁Common in all layers. W_fIs N₃xM matrix (M < N)₃) Column from the critical sampling size N₃Selected from DFT matrices, as shown below

Report only the indices of L selected columns of B and take O₁O₂An over-sampled index of values. Similarly, for W_FReporting only a predefined size N₃The indices of the M selected columns outside the DFT matrix. Thus, L, M represents the equivalent spatial and frequency dimensions after compression, respectively. Finally, a 2L M matrixRepresents Linear Combination Coefficients (LCC) of a vector based on spatial and frequency DFT. Both areAndand are independent for different layers. Reporting to the gNB an amplitude and phase value of about a beta fraction (beta < 1) of the 2LM available coefficients as part of the CSI report, wherein coefficients with zero amplitude are indicated by the each layer bitmap. Since all coefficients reported within a layer are normalized with respect to the coefficient having the largest magnitude (the strongest coefficient), the relative values of the coefficients are set to unity, and the magnitude or phase information of the coefficients is not explicitly reported. Only an indication of the index of the strongest coefficient for each layer is reported. Thus, for single layer transmission, per layer reportingThe magnitude and phase values of the maximum of the coefficients (along with the exponent of the selected L, M DFT vector), which can result in a meaningful reduction in CSI report size.

For a type-II codebook, the UE reports indices of non-zero coefficients for each layer that characterize the precoder across two conversion bases (representing the spatial and frequency dimensions of the codebook). The non-zero coefficient indices are reported in the form of a 2L × M-sized two-dimensional bitmap per layer, where L, M indicates the compressed spatial and frequency base size per polarization, respectively. For a dual polarized antenna, a total of 2L beams per layer are indicated. Non-zero to be reported per layerNumber of coefficients (K)₁) Parameterized by a higher layer parameter β, which satisfies K₁And less than or equal to 2LM beta, wherein beta is less than 1, namely, the number of the channel coefficients fed back to the gNB is a part of the total coefficients. This means that the 2L × M bitmap may be a sparse matrix, where there may be one or more rows (beams) or columns (frequency units) all of zero. Note that the bitmap size may be significant compared to the total overhead, e.g., for a 4-level transmission with typical values of L-4 and M-7, the bitmap may bring up to 224 overhead bits.

Fig. 2 and 3 illustrate an example of the case where L-4 and M-7. Fig. 2 illustrates a size 2L × M bitmap, where x corresponds to a non-zero coefficient position. The bitmap corresponds to a case where, for example,a non-zero coefficient is reported at β 1/4. Thus, there is a possibility that the bitmap matrix is sparse, with many rows and/or columns not being utilized.

This would help to further reduce overhead if we could somehow report the index of the unused beam. For example, we can introduce a new bitmap of size 2L to indicate the unused beams, as shown in fig. 3.

In the case of the not illustrated example, we can see that L '5 bits are utilized across both polarizations, and the overhead of reporting the position of the coefficients can be reduced from 2LM 56 bits to L' M +2L 43 bits, so 13 bits can be saved. For a 4-level transmission, a total of 52 bits in overhead can be reduced, wherein this approach does not involve information loss.

Thereafter, the concept of a layer group is used, wherein a layer group represents a set of one or more beams. One possible arrangement is to group the layers 1, 2 into one layer group (layer group 1) and the layers 3, 4 into another layer group (layer group 2).

Cases where reducing the 2 lxm bitmap size may be advantageous may include examples, where:

1. number of non-zero coefficients (K) within a layer compared to 2LM₁) Is small, particularly at levels R > 2, i.e.,many rows have a high probability of all being zero. Therefore, it is more efficient to have a smaller bitmap for each layer including only the utilized beams.

Possible scenarios for 2.3 to 4 level transmission include orthogonal beams across layers/groups of layers, or in a more general arrangement partially overlapping beams, i.e. only a subset of the beams are allowed to be reused across layers/groups of layers. In such a scenario, for a layer/layer group, multiple beams would not be utilized, and therefore it makes sense to use a bitmap for each layer that does not include these omitted beams.

One possible scenario for 3.3 to 4 level transmission is to utilize a minimum subset of beams that comprise x% of the total WB power of the channel, where x ∈ [0,100 ]. In this case, only a subset of the beams is utilized for each layer/group of layers, so it is more efficient to have a smaller bitmap for each layer.

Feedback in type-II CSI is reported in two consecutive parts in Uplink Control Information (UCI): there is typically a fixed size UCI part 1, which is typically small and used to report parameters indicating the size of the rest of the feedback information; and a UCI section 2, typically of variable size (parameterized by the content in the UCI section 1). Therefore, any parameter indicating that the overhead size may be reduced typically needs to be reported in the UCI part 1.

In accordance with the present application, various embodiments are presented that aim to reduce the overhead per bitmap for a 3-to-4 level transmission by reporting side information that enables coefficient bitmap overhead to be reduced without information loss. More specifically, three different approaches are proposed. The first approach aims to reduce the total overhead bits in the system. The second scheme attempts to preferentially reduce overhead included as part of the UCI part 1, and the third scheme attempts a more balanced method between minimizing the UCI part 1 overhead and the total overhead corresponding to bitmap information.

For ease of illustration, we discuss a proposed scheme for up to 4-level transmission, where the beams are utilized in groups of layers, e.g., layers 1, 2 utilize a common subset of spatial beams, while layers 3, 4 may utilize different subsets of beams, where neither subset is necessarily disjoint. An extension to the layer-based case is also covered, i.e. each layer is associated with a subset of its subset of beams.

Example 1: reporting beam bitmaps for each group of layers in UCI part 1

In this approach, a bitmap of size 2L (we refer to as a beam bitmap) is reported for each group of layers in UCI portion 1, where a zero value for the ith position in the beam bitmap indicates that all coefficient values corresponding to the ith beam position are not reported for any layer within the group of layers corresponding to the beam bitmap. Assume that both beam bitmaps have L_G1、L_G2At non-zero position, layer groups 1 and 2 respectively use L_G1Less than or equal to 2L and L_G2≦ 2L beams, such as for 4-level transmission, layer 1 through layer 4 each utilize a size L compared to a total of 8LM bits_G1M、L_G1M、L_G2M and L_G2A bitmap of M.

At least one advantage of this approach is that the two beam bitmaps provide complete information about the number of beams utilized by each group of layers (for proper assignment of UCI portion-2 size) and the index of such beams (for proper mapping of beams). However, one potential drawback is that all overhead (4L bits in total) will typically be allocated in UCI portion 1, which may need to be small.

This approach can be generalized to the layer-based case, where for the case of reporting R layers, R beam bitmaps will be reported in UCI part 1.

Example 2: reporting the total number of beams utilized in UCI part 1

In this approach, only the total number of beams utilized across two groups of layers is reported in UCI portion 1. Such quantities are usually requiredIs marked, wherein, q'_LThe total number of possible values representing the sum of beams utilized across the layer group is sufficient to indicate the bitmap size included as part of UCI portion 2. In addition, two layer sets will still be indicated in UCI portion 2Corresponding two 2L bitmaps to indicate the location of the beam utilized by each group of layers.

Albeit with the previous method (More bits), this approach typically consumes more overhead bits, but it typically has fewer UCI portion 1 bits than the previous embodiment, which may be an important design criterion in some cases.

This approach can be generalized to the layer-based case with an R layer, where q'_LRepresenting the total number of beams utilized across layers, and R-beam bitmaps of size 2L are each reported in UCI part 2.

Example 3: reporting a beam bitmap in UCI part 1

In this method, one bitmap indicating beam utilization is reported in the UCI section 1. Reporting bit-XOR (we call BP) of the beam bitmaps for layer group 1 and layer group 2 in the two layer/layer group case_x). Note that the beam shared by the two packets is in BP_xWill be indicated with a 0 and all other beams in the XOR beam bitmap will be indicated with a 1. Then, can be determined from BP_xDeriving an upper limit (2L + BP) on the total number of beams utilized_xThe number of 0 entries in). Reporting BP in UCI part 1 compared to directly reporting the total number of beams_xIs that BP is_xComprising two bitmaps for layer group 1 and layer group 2 (hereinafter we will refer to them as BP)_G1And BP_G2) The information of (1). Taking into account BP_G1And BP_xCan realize BP_G2I.e. BP_G2bit-XOR (BP)_G1、BP_G2). Therefore, only BP needs to be reported in UCI part 2_G1。

More generally, this method involves reporting a bitmap BP of size 2L in UCI part 1_xThe bitmap includes information about the total number of beams utilized across the layer group and information about the bitmap of the layer/layer group. Then, in the case of R layers/layer groups, only the R-1 bitmap is typically needed in the UCI part 2.

Extension to the case with arbitrary Frequency Domain (FD) base size per layer/group of layers:

the above-described schemes in embodiments 1 to 3 can be generalized to the case where the FD base size of each layer/layer group is not necessarily the same. Scheme 1 does not need to be changed except to report the FD base size (if needed). In addition to reporting FD base size (if needed), scheme 2 may involve reporting the number of beams (rather than aggregation beams) in each layer/layer group. In addition to reporting FD base size (if needed), scheme 3 may include reporting a possibly additional parameter that represents the number of beams in one or more layers/layer groups.

One approach for higher level transmission utilizes a separate subset of beams for each layer/layer group, where the subsets may be disjoint. If so, bitmap reporting overhead can be meaningfully reduced because some beams are not utilized for a given layer. Therefore, it may be more efficient to indicate only the utilized beams and report a smaller bitmap per layer (which includes information corresponding to the utilized beams), thereby reducing CSI feedback overhead without losing any information.

Each of the three scenarios is summarized below, with the general report format as follows:

UCI-P1: the number of bits to be reported in UCI part 1 to accommodate the proposed method

UCI-P2: number of bits to be reported in UCI part 2 to accommodate the proposed method UCI-total number: the number of bits to be reported in both UCI part 1 and UCI part 2 to accommodate the proposed method.

Scheme 1:

the UCI overhead for scheme 1 for reporting the beams utilized by the two layers/layer groups is as follows:

UCI-part 1: 4L position

UCI-P2: 0 bit

UCI-total number: 4L position

The UCI overhead for scheme 1 for reporting beams utilized by R > 2 layers/layer groups is as follows:

UCI-part 1: 2LR position

UCI-P2: 0 bit

UCI-total number: 2LR position

Scheme 2:

the UCI overhead for scheme 2 for reporting the beams utilized by the two layers/layer groups is as follows:

UCI-P1：

UCI-P2: 4L position

UCI-total number:

q'_Lindicating the number of all possible values of the sum of beams across groups of layers

The UCI overhead for scheme 2 for reporting beams utilized by R layers/layer groups is as follows:

UCI-P1：

UCI-P2: 2LR position

UCI-total number:

q'_Lindicating the number of all possible values of the sum of beams across layers

Scheme 3:

example of UCI overhead for scheme 3 for reporting beams utilized by two layers/layer groups:

reporting two beam bitmaps, BP_xAnd BP_G1(BP_GkA bitmap representing layer group k) as follows:

i)BP_x＝BITXOR(BP_G1、BP_G2). Such a bitmap is transmitted in the UCI part 1. Such a bitmap provides the position of the common beam across the group of layers + the total number of beams across the layers.

ii)Let q＝nnz(BP_x) Where nnz(s) is the number of non-zero entries in vector s. Then, IIt is known that we need at most 2(2L + q) M bits of the coefficient bitmap instead of 8LM bits, and therefore since BP is the cause_xWe can allocate a bitmap of the appropriate size for all layers.

iii) in UCI part 2, another 2L Bitmap (BP)_G1) Representing the location of the beam utilized by the layer group 1. Using BP_xAnd BP_G1We now know the location of the beams utilized by all layer groups, assuming that 4 layers utilize all 2L beams. If R is less than or equal to 2, the bitmap is not sent.

Example 1:

fig. 4-6 illustrate a bitmap diagram identifying beams utilized by a pair of layer groups and a composite bitmap diagram representing a plurality of layer groups, the composite bitmap diagram formed using an exclusive-or operation, according to a first example. More specifically, fig. 4 illustrates an example 400 of two possible beam bitmaps.

In the particular example shown, we are working from BP_G1、BP_G2Knowing L ═ L_G1+L_G2＝5+6＝11。

1. Using BP_x＝BITXOR(BP_G1、BP_G2) We can get an upper limit on the total number of beams used, and

2. using BP_xAnd BP_G1We can obtain BP_G2。

FIG. 5 is based on BP shown in FIG. 4_G1And BP_G2Value of (b) illustrates BP_x。BP_xThe position of 1 in indicates a beam utilized in only one packet group, and BP_xThe position of 0 indicates a beam that is more likely to be utilized in both groups of layers, but in some unlikely cases may also correspond to a case where a beam is not utilized in both cases.

From BP_xWe deduced L ≦ 2nz (BP)_x)+nnz(BP_x) 2 × 3+5 ═ 11, where nz(s) is the number of zero entries in vector s.

Now, as shown in FIG. 6, we can also determine BP_G2＝XOR(BP_x、BP_G1)。

Example 2:

the reason why we are more likely to use the inequalities in the equation for the upper limit and L x above is illustrated in further examples shown in fig. 7 to 9. More specifically, fig. 7 illustrates different examples 700 of two possible beam bitmaps.

From BP_G1、BP_G2We know that L ═ L_G1+L_G2＝5+5＝10。

Next, we calculate BP_xAs shown in fig. 8.

Taking into account BP_x，2nz(BP_x)+nz(BP_x) 2 x 4+5 is 12 beams, so we assume two more beams than in reality.

Taking into account BP_G1And BP_xWe can also determine BP_G2As shown in fig. 9.

In the previous example, the two unutilized beams are considered active because beam 3 is not utilized by any beam group. This would require a slightly higher overhead. However, BP_G2Is completely recovered without any error.

The UCI overhead for scheme 3 for reporting the beams utilized by the two layers/layer groups is as follows:

UCI-part 1: 2L position

UCI-P2: 2L position

UCI-total number: 4L position

The UCI overhead for scheme 3 for reporting beams utilized by R layers/layer groups is as follows:

UCI-part 1:

UCI-P2：

UCI-total number:

in this case, BP_xEach drawn from an alphabet of size R, i.e., { 0., R-1 }.

Note that the schemes 1 to 3 may be further modified in the following manner. For example, one may report utilized beams using a beam bitmap of size L instead of 2L, so the same beam across both polarizations may have the same utilized/unutilized status at each layer/layer group.

Further, schemes 1 through 3 may be modified to a case where the FD base size (M) is not the same across layers/layer groups. Details of the scheme and overhead calculations will be provided thereafter.

Fig. 10 and 11 illustrate tables providing a comparison between schemes 1 through 3 based on the case of layer groups.

Setting: variable beam allocation of two layers/layer groups. M is fixed.

The target is as follows: reducing the total bitmap size to M ∑ L_rInstead of 2LMR, wherein L_r≤2L。

Case a: any beam of each packet, fixed M.

More specifically, fig. 10A and 10B are tables 1000 that compare schemes across layer groups for the case where any beam of each layer group has a fixed frequency domain base size after frequency compression.

For M_G1＝M_G2Summary of the situation (1). Method based on layer groups

Scheme 1:

UCI-P1: 4L position

UCI-P2: 0 bit

UCI-total number: 4L position

Scheme 2:

UCI-P1：

UCI-P2: 4L position

UCI-total number:

q'_Lindication L_G1+L_G2All possible values of (a).

If L is_G1And L_G2Is arbitrary, then q'_L4L-1 (for indication of L)_G1+L_G2From 2 to 4L)

IfAnd isE.g., case 2, then

Scheme 3:

UCI-P1: 2L position

UCI-P2: 2L position

UCI-total number: 4L position

Case B: m_G2≠M_G1. Method based on layer groups

Suppose M_G2＝α_MM_G1Wherein α is_M∈{α_M ⁽¹⁾，α_M ⁽²⁾,.., and a_MIs reported in UCI-P1. In this case, UCI-P1 is requiredAn extra bit.

In this case, you may now need to know both L's from UCI-P1_G1And L_G2To set the bitmap L for layers 1, 2 and 3, 4 respectively_G1×M_G1And L_G2×M_G2. Recall that when M is fixed, only L is needed_G1+L_G2Since we need to allocate a total of 2 (L) for the bitmap_G1+L_G2) M bits.

Scheme 1: except for UIn CI-P1Two bitmaps of size 2L are also transmitted for each layer group in UCI-P1 to indicate the FD base size for each layer group. Total overhead bits of UCI-P1And no UCI-P2 bit is required. The total UCI is then

Fig. 11 is a table 1100 comparing schemes across groups of layers for a case where any beam of each group of layers has unequal frequency domain base sizes after frequency compression, where the frequency domain base size of group 2 is less than (or equal to) the frequency domain base size of group 1.

For M_G2≤M_G1Summary of the situation (1).

Scheme 1:

UCI-P1：

UCI-P2: 0 bit

UCI-total number:

scheme 1 may be extended to a case where R > 2 beam bitmaps of size 2L and UCI-P1 are transmitted in UCI-P1 and UCI-P1, respectivelyTo indicate the FD base size of each layer group.

Scheme 2:

UCI-P1：

UCI-P2: 4L position

UCI-total number:

q”_Lindication pair { L_G1、L_G2All possible values of.

If L is_G1And L_G2Is arbitrary, then q "_L＝(2L)2

If L is_G1≤2Lα_L1And L is_G2≤2Lα_L2Wherein α is_L1、α_L2Is of fixed/higher layer configuration, then

Scheme 2 can be extended to a case where R beam bitmaps of 2L in size, and q ″, are transmitted in UCI-P2, respectively "_L(represented in UCI-P1) will indicate the R-tuple L₁,...,L_RAll possible values of { along with those in UCI-P1 }To indicate the FD base size of each layer group.

Scheme 3:

UCI-P1：

UCI-P2: 2L position

UCI-total number:

q.L denotes L_G1Or L_G2Whichever is of smaller size

If L is_G1And L_G2Is optional, then q x L is 2L

If L is_G1≤2Lα_L1And L is_G2≤2Lα_L2Wherein α is_L1、α_L2Is to fix/compareHigher layer configured, then

Scheme 3 may be extended to the case of R > 2, where R-1 beam bitmaps of size 2L are transmitted in UCI-P2, respectively, and q x L (represented in UCI-P1) will indicate the (R-1) tuple L₁,...,L_R－1All possible values of }, and a map BP of size 2L_x(the entries are drawn from an alphabet of size R, so it is necessary to do soTo report BP_x) Together with that in UCI-P1

Note that for all cases, q L ≦ q "_L。

Fig. 12 is a flow diagram 1200 in a user equipment for generating a channel state information report with information corresponding to a layer set. The method includes receiving 1202 a set of reference signals transmitted from a network including at least one base station. A set of beams is identified 1204 based on a set of reference signals. By transforming the received reference signal set, a pair of amplitude and phase coefficient vectors is obtained 1206, where each pair of amplitude and phase coefficient vectors corresponds to a beam in a set of beams in each of the set of layers. The layers from the layer set are partitioned 1208 into a set of groups. A beam bitmap vector is generated 1210 for each group of layers, the beam bitmap vector indicating a subset of the selected set of beams in the group of layers. Based on the beam bitmap vector, a coefficient bitmap vector is generated 1212 for each beam in the selected beam set in each layer, the coefficient bitmap vector indicating coefficients having non-zero amplitude values. A channel state information report is transmitted 1214 to the network, the channel state information report including at least the beam bitmap vector and the coefficient bitmap vector.

In some cases, the beam bitmap vector for each group of layers may indicate a beam selected by at least one layer within the group of layers.

In some cases, the channel state information report may be divided into at least two portions. In some of these cases, the beam bitmap vector for each layer group may be reported in a preselected portion of the at least two portions of the channel state information report, while the coefficient bitmap vector for each layer is reported in the portion of the channel state information report, which is subsequent to the preselected portion.

In other of these cases, an indication of a sum of bases across a subset of the selected set of beams of the group of layers may be reported in a preselected portion of at least two portions of the channel state information report, while a beam bitmap vector corresponding to each group of layers and a coefficient bitmap vector corresponding to each layer are reported in the portion of the channel state information report, the portion following the preselected portion. Further, the indication of the sum of the reported cardinalities in a preselected portion of the at least two portions of the channel state information report may represent a composite value of the sum of the selected beams for each group of layers.

In other of these cases, the entry in the beam bitmap vector may have a particular binary value if the corresponding beam belongs to the beam subset vector, and a complementary binary value that is the complement of the particular binary value if the corresponding beam does not belong to the beam subset vector. Further, the element-by-element functions of the beam bitmap vectors of two or more layer groups may be reported in a preselected portion of the at least two portions of the channel state information report, while the coefficient bitmap vector and the beam bitmap vector for each layer are reported in the portion of the channel state information report, which follows the preselected portion. Additional indicators may be reported in a preselected portion of the at least two portions of the channel state information report that reflect the sum of the selected beams for each subset of groups of layers, the subset including less than all of the groups of layers.

In some cases, the length of the beam bitmap vector for each packet is the number of beams selected in each polarization.

Fig. 13 is a flow diagram 1300 associated with receiving a channel state information report with information corresponding to a layer set in a network. The method includes transmitting 1302 a set of reference signals transmitted to a user equipment. A set of beams is identified 1304 based on a set of reference signals. A pair of amplitude and phase coefficient vectors is obtained 1306 by transforming the received reference signal set, wherein each pair of amplitude and phase coefficient vectors corresponds to a beam in a set of beams in each of the set of layers. The layers from the layer set are divided 1308 into a set of groups. A beam bitmap vector is generated 1310 for each group of layers, the beam bitmap vector indicating a subset of the selected set of beams in the group of layers. Based on the beam bitmap vector, a coefficient bitmap vector is generated 1312 for each beam in the selected beam set in each layer, the coefficient bitmap vector indicating coefficients having non-zero amplitude values. A channel state information report is received 1314 from a user equipment, the channel state information report including at least a beam bitmap vector and a coefficient bitmap vector.

It should be understood that although there are specific steps shown in the figures, various additional or different steps may be performed according to embodiments, and one or more specific steps may be rearranged, repeated, or eliminated entirely according to embodiments. Also, some steps performed may be repeated simultaneously on a continuing or continuous basis as other steps are performed. Further, different steps may be performed by different elements or within a single element of the disclosed embodiments.

Fig. 14 is an example block diagram of an apparatus 1400, such as UE 110, network entity 120, or any other wireless communication device disclosed herein, according to a possible embodiment. The apparatus 1400 may include a housing 1410, a controller 1420 coupled to the housing 1410, audio input and output circuitry 1430 coupled to the controller 1420, a display 1440 coupled to the controller 1420, a memory 1450 coupled to the controller 1420, a user interface 1460 coupled to the controller 1420, a transceiver 1470 coupled to the controller 1420, at least one antenna 1475 coupled to the transceiver 1470, and a network interface 1480 coupled to the controller 1420. Apparatus 1400 may not necessarily include all of the illustrated elements and/or may include additional elements of different embodiments of the disclosure. The apparatus 1400 may perform the methods described in all embodiments.

The display 1440 may be a viewfinder, a Liquid Crystal Display (LCD), a Light Emitting Diode (LED) display, an Organic Light Emitting Diode (OLED) display, a plasma display, a projection display, a touch screen, or any other device that displays information. The transceiver 1470 may be one or more transceivers that may include a transmitter and/or a receiver. The audio input and output circuitry 1430 may include a microphone, a speaker, a transducer, or any other audio input and output circuitry. The user interface 1460 may include a keypad, keyboard, buttons, touchpad, joystick, touchscreen display, another additional display, or any other device for providing an interface between a user and an electronic device. Network interface 1480 may be a Universal Serial Bus (USB) port, an ethernet port, an infrared transmitter/receiver, an IEEE 1394 port, a wireless transceiver, a WLAN transceiver, or any other interface that can connect a device to a network, appliance, and/or computer and that can transmit and receive data communication signals. The memory 1450 may include Random Access Memory (RAM), Read Only Memory (ROM), optical memory, solid state memory, flash memory, removable memory, a hard drive, cache, or any other memory that may be coupled to the apparatus.

The apparatus 1400 or controller 1420 may implement any operating system, such as Microsoft WindowsAndroid^TMOr any other operating system. For example, the device operating software may be written in any programming language, such as C, C + +, Java, or Visual Basic. The device software may also run on an application framework such as, for example,a frame,A framework or any other application framework. Software and/or an operating system can be stored in the memory 1450, anywhere on the apparatus 1400, in cloud storage, and/or where software can be stored and ≧ be storedOr anywhere in the operating system. The apparatus 1400 or the controller 1420 may also use hardware to implement the disclosed operations. For example, controller 1420 may be any programmable processor. Further, the controller 1420 may perform some or all of the disclosed operations. For example, some operations may be performed using cloud computing and controller 1420 may perform other operations. The disclosed embodiments may also be implemented on a general-purpose or special-purpose computer, a programmed microprocessor or microprocessors, peripheral integrated circuit elements, application specific integrated circuits or other integrated circuits, hardware/electronic logic circuits (such as discrete element circuits), programmable logic devices (such as programmable logic arrays, field programmable gate arrays), or the like. In general, the controller 1420 may be any controller or processor device(s) capable of operating an apparatus and implementing the disclosed embodiments. Some or all of the additional elements of the apparatus 1400 may also perform some or all of the operations of the disclosed embodiments. At least some embodiments may provide a method and apparatus for generating a channel state information report having information corresponding to a layer set.

At least some methods of the present disclosure may be implemented on a programmed processor. However, the controllers, flow charts and/or modules may also be implemented on a general purpose or special purpose computer, a programmed microprocessor or microcontroller and peripheral integrated circuit elements, integrated circuits, hardware electronic or logic circuits (such as discrete element circuits), programmable logic devices or the like. In general, any device on which resides a finite state machine capable of implementing the flowcharts shown in the figures may be used to implement the processor functions of this disclosure.

At least some embodiments may improve the operation of the disclosed apparatus. Also, while the present disclosure has been described with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will become apparent to those skilled in the art. For example, various components of the embodiments may be interchanged, added, or substituted in the other embodiments. Also, not all of the elements of each figure may be necessary for operation of the disclosed embodiments. For example, one of ordinary skill in the art of the disclosed embodiments would be able to implement and use the teachings of the present disclosure by using the elements of the independent claims only. Accordingly, the embodiments of the disclosure as set forth herein are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the disclosure.

In this document, relational terms such as "first," "second," and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The phrase "at least one of," selected from the group of, "or" at least one selected from "of a list, followed by the list, is defined to mean one, some, or all, but not necessarily all, of the elements in the list. The terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Absent further constraints, elements prefaced by "a," "an," etc. do not preclude the presence of additional identical elements in a process, method, article, or apparatus that comprises the elements. Likewise, the term "another" is at least defined as one or more. As used herein, the terms "comprising," having, "and the like are defined as" comprising. Furthermore, the background section is written as an understanding by the inventors themselves of the context of some embodiments at the time of filing, and includes the inventors' own recognition of any problems with the prior art and/or problems encountered by the inventors during their work.