阅读说明：本技术 用于在通信系统中发射探测参考信号的装置和方法 (Apparatus and method for transmitting sounding reference signal in communication system ) 是由 阿里斯·帕帕萨克拉里欧 于 2017-03-14 设计创作，主要内容包括：本公开涉及待被提供用于支持超越第4代(4G)通信系统(诸如长期演进(LTE))的更高数据速率的准第5代(5G)或5G通信系统。根据各种实施例,提供一种配置有用于时分双工(TDD)的一个以上服务小区的用户设备(UE)的装置。所述装置包括至少一个收发器以及操作性地联接到所述至少一个收发器的至少一个处理器。所述至少一个收发器被配置为接收使用包括用于发射功率控制(TPC)命令的第一信息和用于探测参考信号(SRS)请求的第二信息的下行链路控制信息(DCI)格式的DCI,并且基于所述DCI来发射SRS。(The present disclosure relates to a quasi-generation-5 (5G) or 5G communication system to be provided for supporting higher data rates beyond a generation-4 (4G) communication system, such as Long Term Evolution (LTE). According to various embodiments, an apparatus of a User Equipment (UE) configured with more than one serving cell for Time Division Duplex (TDD) is provided. The apparatus includes at least one transceiver and at least one processor operatively coupled to the at least one transceiver. The at least one transceiver is configured to receive Downlink Control Information (DCI) using a DCI format including first information for Transmit Power Control (TPC) commands and second information for Sounding Reference Signal (SRS) requests, and transmit SRS based on the DCI.)

1. A user equipment, UE, (111) comprised in one or more UEs (111-116) in a wireless communication system, the UE (111) comprising:

at least one transceiver (310); and

at least one processor (340) operably coupled to the at least one transceiver (310), the at least one processor configured to:

receiving downlink control information, DCI, format from a base station, BS, (102), said DCI format comprising a plurality of blocks, each block corresponding to one UE (111) 116, said one or more blocks comprising a block for said UE (111), wherein said block for said UE (111) comprises bits for aperiodic sounding reference signal, A-SRS, requests and bits for transmit power control, TPC, commands, and

transmitting an A-SRS to the BS (102) based on the value of the bit for the TPC command and the value of the bit for the A-SRS request,

wherein the transmission power of the A-SRS is determined to be the smaller of the first value and the second value,

wherein the first value is a maximum transmit power of the A-SRS on a serving cell of the UE (111),

wherein the second value is determined based on a power control parameter, the power control parameter comprising: a bandwidth of transmission of the A-SRS on the serving cell, a pathloss value measured on the serving cell, a transmit power control adjustment state on the serving cell determined from the TPC commands, and higher layer parameters for the serving cell.

2. Method for operating a user equipment, UE, (111) comprised in one or more UEs (111-116) in a wireless communication system, the method comprising:

receiving downlink control information, DCI, format from a base station, BS, (102), said DCI format comprising a plurality of blocks, each block corresponding to one UE (111) 116, said one or more blocks comprising a block for said UE (111), wherein said block for said UE (111) comprises bits for aperiodic sounding reference signal, A-SRS, requests and bits for transmit power control, TPC, commands, and

transmitting an A-SRS to the BS (102) based on the value of the bit for the TPC command and the value of the bit for the A-SRS request,

wherein the transmission power of the A-SRS is determined to be the smaller of the first value and the second value,

wherein the first value is a maximum transmit power of the A-SRS on a serving cell of the UE (111),

wherein the second value is determined based on a power control parameter, the power control parameter comprising: a bandwidth of transmission of the A-SRS on the serving cell, a pathloss value measured on the serving cell, a transmit power control adjustment state on the serving cell determined from the TPC commands, and higher layer parameters for the serving cell.

3. A base station (102) comprising:

at least one transceiver (310); and

at least one processor (340) operably coupled to the at least one transceiver (310), the at least one processor configured to:

transmitting a downlink control information, DCI, format to a user equipment, UE, (111), said DCI format comprising a plurality of blocks, each block corresponding to one UE (111) 116, said one or more blocks comprising a block for said UE (111), wherein said block for said UE (111) comprises bits for aperiodic sounding reference signal, A-SRS, requests and bits for transmit power control, TPC, commands, and

receiving from the UE (111) an A-SRS transmitted based on values of bits for the TPC command and values of bits for the A-SRS request,

wherein the transmission power of the A-SRS is determined to be the smaller of the first value and the second value,

wherein the first value is a maximum transmit power of the A-SRS on a serving cell of the UE (111),

wherein the second value is determined based on a power control parameter, the power control parameter comprising: a bandwidth of transmission of the A-SRS on the serving cell, a pathloss value measured on the serving cell, a transmit power control adjustment state on the serving cell determined from the TPC commands, and higher layer parameters for the serving cell.

4. A method for operating a base station (102), the method comprising:

transmitting a downlink control information, DCI, format to a user equipment, UE, (111), said DCI format comprising a plurality of blocks, each block corresponding to one UE (111) 116, said one or more blocks comprising a block for said UE (111), wherein said block for said UE (111) comprises bits for aperiodic sounding reference signal, A-SRS, requests and bits for transmit power control, TPC, commands, and

receiving from the UE (111) an A-SRS transmitted based on values of bits for the TPC command and values of bits for the A-SRS request,

wherein the transmission power of the A-SRS is determined to be the smaller of the first value and the second value,

wherein the first value is a maximum transmit power of the A-SRS on a serving cell of the UE (111),

wherein the second value is determined based on a power control parameter, the power control parameter comprising: a bandwidth of transmission of the A-SRS on the serving cell, a pathloss value measured on the serving cell, a transmit power control adjustment state on the serving cell determined from the TPC commands, and higher layer parameters for the serving cell.

5. The UE (111) of claim 1, the method of claim 2, the BS (102) of claim 3 or the method of claim 4,

wherein a transmit power P of the A-SRS in decibels per milliwatt (dBm) in time point i and on serving cell c_SRS,c(i) Determining based on:

P_SRS,c(i)＝min{P_CMAX,c(i),10log₁₀(M_SRS,c)+P_{O_SRS,c}(m)+α_SRS,c·PL_c+f_c(i)}dBm，

min x, y is a minimum function, and can yield the smaller of the numbers x, y,

log₁₀(x) Is a base-10 logarithmic function, and is capable of producing a base-10 logarithm of the number x,

P_CMAX,c(i) is the maximum transmit power in time point i configured by higher layers for the serving cell c,

M_SRS,cis a bandwidth for transmitting the a-SRS in a time point i and on the serving cell c,

P_{O_SRS,c}(m) is configured by a higher layer for the serving cell c, when an A-SRS transmission is configured by a higher layer, m is 0, and when the A-SRS transmission is configured by the DCI format, m is 1,

PL_cis the pathloss value measured on the serving cell c,

α_SRS,cis configured by a higher layer for the A-SRS on the serving cell c, and

f_c(i) is a transmit power control adjustment state, determined from the TPC command in the DCI format for the a-SRS transmission in time point i and on the serving cell c.

6. The UE (111) of claim 5, the method of claim 5, the BS (102) of claim 5 or the method of claim 5,

wherein a Power Headroom (PH) for transmitting the A-SRS in the time point i and on the serving cell c is determined based on:

PH_c(i)＝P_CMAX,c(i)-{10log₁₀(M_SRS,c(i))+P_{O_SRS,c}(m)+α_SRS,c·PL_c+f_c(i)}。

7. the UE (111) according to claim 6, the method according to claim 6, the BS (102) according to claim 6 or the method according to claim 6, wherein:

f_c(0)＝ΔP_rampup,c，

ΔP_rampup,c＝min[{max(0,P_CMAX,c-(10log₁₀(M_SRS,c)+P_{O_SRS,c}(m)+α_SRS,c·PL_c))},ΔP_{rampupreqeusted,c}]，

max x, y is a function of the maximum, and can yield the larger of the numbers x, y,

M_SRS,cis a bandwidth in which the A-SRS is transmitted at a time point of a first A-SRS transmission on the serving cell c, and

ΔP_{rampuprequested,c}is the total power transmitted from the first to the last random access preamble on the serving cell c ramping up the power and is configured by higher layers.

Technical Field

The present disclosure relates generally to wireless communication systems. More particularly, the present disclosure relates to an apparatus and method for transmitting a sounding reference signal in a communication system.

Background

To meet the demand for increased wireless data services since the deployment of 4 th generation (4G) communication systems, efforts have been made to develop improved 5 th generation (5G) or quasi-5G communication systems. Accordingly, the 5G or quasi-5G communication system is also referred to as an "ultra 4G network" or a "Long Term Evolution (LTE) system".

5G communication systems are considered to be implemented in the higher frequency (mmWave) band (e.g., 28GHz or 60GHz band) in order to achieve higher data rates. In order to reduce propagation loss of radio waves and increase transmission distance, beamforming, massive Multiple Input Multiple Output (MIMO), full-dimensional MIMO (FD-MIMO), array antenna, analog beamforming, massive antenna technology are discussed in the 5G communication system.

In addition, in the 5G communication system, development of system network improvement is ongoing based on advanced small cells, cloud Radio Access Network (RAN), ultra dense network, device-to-device (D2D) communication, wireless backhaul, mobile network, cooperative communication, coordinated multipoint (CoMP), reception side interference cancellation, and the like.

In 5G systems, hybrid Frequency Shift Keying (FSK) and quadrature amplitude modulation (FQAM) and Sliding Window Superposition Coding (SWSC) have been developed as Advanced Coding Modulation (ACM) and filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA) and Sparse Code Multiple Access (SCMA) as advanced access techniques.

Wireless communication is one of the most successful innovations in modern history. Recently, the number of subscribers to wireless communication services has exceeded fifty billion and continues to grow rapidly. The demand for wireless data services is rapidly increasing due to the increasing popularity of smart phones and other mobile data devices, such as tablet computers, "notebook" computers, netbooks, e-book readers, and machine type devices, among consumers and businesses. In order to meet the high growth of mobile data traffic and support new applications and deployments, improvements in radio interface efficiency and coverage are of paramount importance.

Disclosure of Invention

Problem solving scheme

Various embodiments of the present disclosure provide methods and apparatus for CSI reporting.

In one embodiment, an apparatus of a User Equipment (UE) configured with more than one serving cell for Time Division Duplex (TDD) is provided. The apparatus includes at least one transceiver and at least one processor operatively coupled to the at least one transceiver. The at least one transceiver is configured to receive Downlink Control Information (DCI) using a DCI format, wherein the DCI format includes first information for Transmit Power Control (TPC) commands and second information for Sounding Reference Signal (SRS) requests, and transmit SRS based on the DCI.

In another embodiment, a method is provided for operating a UE configured with more than one serving cell for TDD. The method includes receiving DCI using a DCI format including first information for a TPC command and second information for an SRS request, and transmitting an SRS based on the DCI.

In yet another embodiment, an apparatus of a Base Station (BS) is provided. The apparatus includes at least one transceiver and at least one processor operatively coupled to the at least one transceiver. The at least one transceiver is configured to transmit DCI using a DCI format to a UE configured with more than one serving cell for TDD, the DCI format including first information for a TPC command and second information for an SRS request.

In yet another embodiment, a method for operating a BS is provided. The method includes transmitting, to a UE configured with more than one serving cell for TDD, DCI using a DCI format including first information for a TPC command and second information for an SRS.

Other technical features may be readily apparent to one skilled in the art from the following figures, descriptions, and claims.

Before the following detailed description is made, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document. The term "couple" and its derivatives refer to any direct or indirect communication between two or more elements, whether or not those elements are in physical contact with one another. The terms "transmit," "receive," and "communicate," as well as derivatives thereof, encompass both direct and indirect communication. The terms "include" and "comprise," as well as derivatives thereof, mean inclusion without limitation. The term "or" is inclusive, meaning and/or. The phrase "associated with … …," and derivatives thereof, means including, included within … …, interconnected with … …, contained within … …, connected to or with … …, coupled to or with … …, capable of communicating with … …, cooperating with … …, interleaved, juxtaposed, proximate to, bound to or with … …, having the nature of … …, having a relationship with … …, having a relationship with … …, and the like. The term "controller" means any device, system, or part thereof that controls at least one operation. Such controllers may be implemented in hardware or a combination of hardware and software and/or firmware. The functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. The phrase "at least one of … …," when used with a list of items, means that different combinations of one or more of the listed items can be used and only one item in the list may be required. For example, "at least one of A, B and C" includes any of the following combinations: a; b; c; a and B; a and C; b and C; and A, B and C.

Further, the various functions described below can be implemented or supported by one or more computer programs, each of which is formed from computer-readable program code and embodied in a computer-readable medium. The terms "application" and "program" refer to one or more computer programs, software components, sets of instructions, programs, functions, objects, classes, instances, related data, or portions thereof adapted for implementation in suitable computer readable program code. The phrase "computer readable program code" includes any type of computer code, including source code, object code, and executable code. The phrase "computer readable medium" includes any type of medium capable of being accessed by a computer, such as Read Only Memory (ROM), Random Access Memory (RAM), a hard disk drive, a Compact Disc (CD), a Digital Video Disc (DVD), or any other type of memory. A "non-transitory" computer-readable medium does not include a wired, wireless, optical, or other communication link that transmits transitory electrical or other signals. Non-transitory computer readable media include media capable of permanently storing data as well as media capable of storing and later rewriting data, such as re-writable optical disks or erasable memory devices.

Definitions for certain other words and phrases are provided throughout this patent document. Those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases.

Drawings

For a more complete understanding of the present disclosure and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which like reference numbers represent like parts:

fig. 1 illustrates an example wireless network in accordance with some embodiments of the present disclosure;

fig. 2A and 2B illustrate exemplary wireless transmit and receive paths, according to some embodiments of the present disclosure;

fig. 3A illustrates an exemplary user equipment, in accordance with some embodiments of the present disclosure;

fig. 3B illustrates an example enhanced nodeb (enb) in accordance with some embodiments of the present disclosure;

fig. 4 shows a PUSCH transmission structure;

fig. 5 shows a transmitter block diagram for data information and Uplink Control Information (UCI) in PUSCH according to some embodiments of the present disclosure;

fig. 6 illustrates a receiver block diagram for data information and UCI in PUSCH according to some embodiments of the present disclosure;

fig. 7 illustrates an example transmitter structure for a Zadoff-chu (zc) sequence, according to some embodiments of the present disclosure;

figure 8 illustrates an example receiver structure for ZC sequences, according to some embodiments of the present disclosure;

fig. 9 is a diagram illustrating communications using CA according to some embodiments of the present disclosure;

fig. 10 illustrates the timing of a-SRS transmissions from a UE in a cell in which the UE is not configured for other UL transmissions, in accordance with some embodiments of the present disclosure;

fig. 11 illustrates puncturing of a last SF symbol for PUSCH or PUCCH transmission in a second cell for transmitting SRS in a first cell, in accordance with some embodiments of the present disclosure;

fig. 12 illustrates content of a Downlink Control Information (DCI) format with a Cyclic Redundancy Check (CRC) scrambled by an SRS-cell Radio Network Temporary Identifier (RNTI) indicating whether a UE transmits an aperiodic SRS (a-SRS) in a cell, in accordance with some embodiments of the present disclosure;

fig. 13 illustrates the contents of a DCI format with a CRC scrambled by an SRS-RNTI indicating whether a UE transmits an a-SRS in a cell and indicating Transmit Power Control (TPC) commands for the UE to apply to SRS transmit power, in accordance with some embodiments of the present disclosure; and

fig. 14 illustrates a-SRS transmission triggered by one DCI format in multiple SFs using frequency hopping, according to some embodiments of the present disclosure.

Detailed Description

Figures 1 through 14, discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged wireless communication system.

The following literature and standard descriptions are hereby incorporated by reference into this disclosure as if fully set forth herein:

3 rd generation partnership project (3GPP) TS 36.211v13.1.0, "E-UTRA, Physical channels and modulation" ("REF 1"); 3GPP TS 36.212v13.1.0, "E-UTRA, Multiplexing and Channel coding" ("REF 2"); 3GPP TS 36.213v13.1.0, "E-UTRA, Physical Layer Procedures" ("REF 3"); 3GPP TS 36.321v13.1.0, "E-UTRA, Medium Access Control (MAC) protocol specification" ("REF 4"); 3GPP TS 36.331v13.1.0, "E-UTRA, Radio Resource Control (RRC) Protocol Specification" ("REF 5"); and U.S. patent application Ser. No. 15/152,461, "Control Channel Transmission and Frequency Error Correction" ("REF 6").

The present disclosure relates to a User Equipment (UE) configured for operating with Carrier Aggregation (CA) in a communication system using Time Division Duplex (TDD). The present disclosure enables Sounding Reference Signal (SRS) transmissions from a UE in a cell in which the UE is not configured for other Uplink (UL) transmissions.

Fig. 1 illustrates an example wireless network 100 in accordance with some embodiments of the present disclosure. The embodiment of the wireless network 100 shown in fig. 1 is for illustration only. Other embodiments of the wireless network 100 can be used without departing from the scope of this disclosure.

The wireless network 100 includes an enodeb (eNB)101, an eNB 102, and an eNB 103. The eNB101 communicates with the eNB 102 and the eNB 103. The eNB101 also communicates with at least one Internet Protocol (IP) network 130, such as the internet, a private IP network, or other data network.

Other well-known terms may be used instead of "eNodeB" or "eNB", such as "base station" or "access point", depending on the network type. For convenience, the terms "eNodeB" and "eNB" are used in this patent document to refer to network infrastructure components that provide wireless access to remote terminals. In addition, other well-known terms may be used instead of "user equipment" or "UE," such as "mobile station," "subscriber station," "remote terminal," "wireless terminal," or "user device," depending on the type of network. For convenience, the terms "user equipment" and "UE" are used in this patent document to refer to a remote wireless device that wirelessly accesses an eNB, regardless of whether the UE is a mobile device (such as a mobile phone or smartphone) or is generally considered a stationary device (such as a desktop computer or vending machine).

eNB 102 provides wireless broadband access to network 130 for a first plurality of User Equipments (UEs) located within coverage area 120 of eNB 102. The first plurality of UEs includes: UE 111, which may be located in a Small Business (SB); a UE 112, which may be located in enterprise (E); UE 113, which may be located in a WiFi Hotspot (HS); a UE 114, which may be located in a first residence (R); a UE 115, which may be located in a second residence (R); and a UE 116, which may be a mobile device (M) such as a cellular phone, wireless laptop, wireless PDA, or the like. eNB 103 provides wireless broadband access to network 130 for a second plurality of UEs located within coverage area 125 of eNB 103. The second plurality of UEs includes UE 115 and UE 116. In some embodiments, one or more of the enbs 101-103 may communicate with each other and with UEs 111-116 using 5G, Long Term Evolution (LTE), LTE-A, WiMAX, or other advanced wireless communication technologies.

The dashed lines show the general extent of coverage areas 120 and 125, which are shown as being generally circular for purposes of illustration and explanation only. It should be clearly understood that the coverage areas associated with the enbs, such as coverage areas 120 and 125, may have other shapes, including irregular shapes, depending on the configuration of the enbs and the variations in the radio environment associated with natural and man-made obstructions.

As described in more detail below, one or more of BS 101, BS 102, and BS 103 include a 2D antenna array as described in embodiments of the present disclosure. In some embodiments, one or more of BS 101, BS 102, and BS 103 support sounding reference signal transmission in a Time Division Duplex (TDD) system with carrier aggregation.

Although fig. 1 shows one example of a wireless network 100, various changes may be made to fig. 1. For example, wireless network 100 can include any number of enbs and any number of UEs in any suitable arrangement. In addition, the eNB101 can communicate directly with any number of UEs and provide those UEs with wireless broadband access to the network 130. Similarly, each eNB 102-103 can communicate directly with network 130 and provide direct wireless broadband access to network 130 to the UEs. Further, the enbs 101, 102 and/or 103 may be capable of providing access to other or additional external networks, such as external telephone networks or other types of data networks.

Fig. 2A and 2B illustrate exemplary wireless transmit and receive paths, according to some embodiments of the present disclosure. In the following description, transmit path 200 may be described as being implemented in an eNB (such as eNB 102), while receive path 250 may be described as being implemented in a UE (such as UE 116). However, it will be understood that the receive path 250 can be implemented in an eNB and the transmit path 200 can be implemented in a UE. In some embodiments, receive path 250 is configured to support sounding reference signal transmission using carrier aggregation as described in embodiments of the present disclosure.

The transmit path 200 includes a channel coding and modulation block 205, a serial-to-parallel (S-to-P) block 210, an Inverse Fast Fourier Transform (IFFT) block 215 of size N, a parallel-to-serial (P-to-S) block 220, an add cyclic prefix block 225, and an up-converter (UC) 230. Receive path 250 includes down-converter (DC)255, remove cyclic prefix block 260, serial-to-parallel (S-to-P) block 265, size N Fast Fourier Transform (FFT) block 270, parallel-to-serial (P-to-S) block 275, and channel decode and demodulation block 280.

In the transmit path 200, a channel coding and modulation block 205 receives a set of information bits, applies coding, such as Low Density Parity Check (LDPC) coding, and modulates (such as using Quadrature Phase Shift Keying (QPSK) or Quadrature Amplitude Modulation (QAM)) the input bits to generate a series of frequency domain modulation symbols. The serial-to-parallel block 210 converts (such as demultiplexes) the serial modulation symbols into parallel data to generate N parallel symbol streams, where N is the IFFT/FFT size used in the eNB 102 and UE 116. IFFT block 215 of size N performs an IFFT operation on the N parallel symbol streams to generate a time domain output signal. Parallel-to-serial block 220 converts (such as multiplexes) the parallel time-domain output symbols from size-N IFFT block 215 to generate a serial time-domain signal. Add cyclic prefix block 225 inserts a cyclic prefix to the time domain signal. Upconverter 230 modulates (such as upconverts) the output of add cyclic prefix block 225 to an RF frequency for transmission over a wireless channel. The signal may also be filtered at baseband before conversion to RF frequency.

The transmitted RF signal from the eNB 102 arrives at the UE 116 after passing through the wireless channel, and the reverse operation to that at the eNB 102 is performed at the UE 116. Down-converter 255 down-converts the received signal to a baseband frequency and remove cyclic prefix block 260 removes the cyclic prefix to generate a serial time-domain baseband signal. Serial-to-parallel block 265 converts the time-domain baseband signal to parallel time-domain signals. An FFT block 270 of size N performs an FFT algorithm to generate N parallel frequency domain signals. Parallel-to-serial block 275 converts the parallel frequency domain signal to a series of modulated data symbols. Channel decoding and demodulation block 280 demodulates and decodes the modulated symbols to recover the original input data stream.

each of the enbs 101-103 may implement a transmit path 200 similar to transmitting to the UEs 111-116 in the downlink and may implement a receive path 250 similar to receiving from the UEs 111-116 in the uplink. Similarly, each of the UEs 111-116 may implement a transmit path 200 for transmitting in the uplink to the enbs 101-103 and may implement a receive path 250 for receiving in the downlink from the enbs 101-103.

Each of the components in fig. 2A and 2B can be implemented using hardware only or using a combination of hardware and software/firmware. As a particular example, at least some of the components in fig. 2A and 2B may be implemented in software, while other components may be implemented in configurable hardware or a mixture of software and configurable hardware. For example, FFT block 270 and IFFT block 215 may be implemented as configurable software algorithms, where the value of size N may be modified depending on the implementation.

Furthermore, although described as using an FFT and IFFT, this is for illustration only and should not be construed as limiting the scope of the disclosure. Other types of transforms can be used, such as Discrete Fourier Transform (DFT) and Inverse Discrete Fourier Transform (IDFT) functions. It will be appreciated that the value of the variable N may be any integer (such as 1,2, 3, 4, etc.) for DFT and IDFT functions, and any integer that is a power of two (such as 1,2, 4, 8, 16, etc.) for FFT and IFFT functions.

Although fig. 2A and 2B show examples of wireless transmit and receive paths, various changes may be made to fig. 2A and 2B. For example, the various components in fig. 2A and 2B can be combined, further subdivided, or omitted, and additional components can be added according to particular needs. In addition, fig. 2A and 2B are intended to illustrate examples of the types of transmit and receive paths that can be used in a wireless network. Any other suitable architecture can be used to support wireless communications in a wireless network.

Fig. 3A illustrates an example UE 116 in accordance with some embodiments of the present disclosure. The embodiment of UE 116 shown in fig. 3A is for illustration only, and UEs 111-115 of fig. 1 can have the same or similar configurations. However, UEs are in a wide variety of configurations, and fig. 3A does not limit the scope of the disclosure to any particular implementation of a UE.

The UE 116 includes an antenna 305, a Radio Frequency (RF) transceiver 310, Transmit (TX) processing circuitry 315, a microphone 320, and Receive (RX) processing circuitry 325. The UE 116 also includes a speaker 330, a main processor 340, an input/output (I/O) Interface (IF)345, a keypad 350, a display 355, and a memory 360. Memory 360 includes a basic Operating System (OS) program 361 and one or more application programs 362.

The RF transceiver 310 receives from the antenna 305 an incoming RF signal transmitted by an eNB of the network 100. The RF transceiver 310 down-converts an incoming RF signal to generate an Intermediate Frequency (IF) or baseband signal. The IF or baseband signal is sent to RX processing circuitry 325, which generates a processed baseband signal by filtering, decoding, and/or digitizing the baseband or IF signal. RX processing circuitry 325 transmits the processed baseband signal to speaker 330 (such as for voice data) or to main processor 340 for further processing (such as for web browsing data).

TX processing circuitry 315 receives analog or digital voice data from microphone 320 or other outgoing baseband data (such as network data, e-mail, or interactive video game data) from main processor 340. TX processing circuitry 315 encodes, multiplexes, and/or digitizes the outgoing baseband data to generate a processed baseband or IF signal. RF transceiver 310 receives the outgoing processed baseband or IF signal from TX processing circuitry 315 and upconverts the baseband or IF signal to an RF signal that is transmitted via antenna 305.

Main processor 340 can include one or more processors or other processing devices and executes basic OS programs 361 stored in memory 360 in order to control overall operation of UE 116. For example, main processor 340 may be capable of controlling the reception of forward channel signals and the transmission of reverse channel signals by RF transceiver 310, RX processing circuitry 325, and TX processing circuitry 315 in accordance with well-known principles. In some embodiments, main processor 340 includes at least one microprocessor or microcontroller.

Main processor 340 is also capable of executing other processes and programs resident in memory 360, such as operations for channel quality measurement and reporting for systems having 2D antenna arrays as described in embodiments of the present disclosure, as described in embodiments of the present disclosure. Main processor 340 is capable of moving data into or out of memory 360 as needed for the execution process. In some embodiments, main processor 340 is configured to execute application 362 based on OS program 361 or in response to a signal received from an eNB or operator. Main processor 340 is also coupled to I/O interface 345, which provides UE 116 with the ability to connect to other devices, such as laptop computers and handheld computers. I/O interface 345 is the communication path between these accessories and main processor 340.

Main processor 340 is also coupled to keypad 350 and display unit 355. The operator of the UE 116 can use the keypad 350 to enter data into the UE 116. Display 355 may be a liquid crystal display or other display capable of presenting text and/or at least limited graphics, such as from a website.

Memory 360 is coupled to main processor 340. A portion of memory 360 can include Random Access Memory (RAM), and another portion of memory 360 can include flash memory or other Read Only Memory (ROM).

Although fig. 3A shows one example of the UE 116, various changes may be made to fig. 3A. For example, the various components in fig. 3A can be combined, further subdivided, or omitted, and additional components can be added according to particular needs. As a particular example, main processor 340 can be divided into multiple processors, such as one or more Central Processing Units (CPUs) and one or more Graphics Processing Units (GPUs). Further, although fig. 3A shows the UE 116 configured as a mobile phone or smartphone, the UE can be configured to operate as other types of mobile or stationary devices.

According to various embodiments, a User Equipment (UE) comprises: a receiver configured to receive a Downlink Control Information (DCI) format comprising a first plurality of bit blocks and a second plurality of bit blocks from the first plurality of bit blocks, wherein a bit block comprises only a positive number of bits for a Transmit Power Control (TPC) command and a plurality of bits for a Sounding Reference Signal (SRS) request; and a transmitter configured to transmit the SRS with a power adjusted based on a value of the TPC command in a first bit block from the second plurality of bit blocks. When the number of bits for the SRS request in the first bit block is a positive number, the SRS transmission is performed in response to the value of the SRS request, and when the number of bits for the SRS request in the first bit block is zero, the SRS transmission is performed in response to a configuration made by a higher layer.

In one example, the TPC commands are only applicable to adjusting SRS transmit power.

In another example, the second plurality of bit blocks is greater than one, a first bit block from the second plurality of bit blocks is suitable for SRS transmission on the first cell, and a second bit block from the second plurality of bit blocks is suitable for SRS transmission on the second cell.

In yet another example, the DCI format size is equal to a size of a second DCI format including only a second TPC command, and the TPC command from the second TPC command is used to adjust a transmit power of a channel transmitting data information.

In yet another example, the SRS transmission is made on a cell that does not transmit a channel conveying data information.

In yet another example, the SRS is transmitted from the plurality of groups of antennas at a plurality of respective points in time.

In yet another example, SRS transmit power P in decibel per milliwatt (dBm) in time point i and on cell c_SRS,c(i) Comprises the following steps:

P_SRS,c(i)＝min{P_CMAX,c(i),10log₁₀(M_SRS,c)+P_{O_SRS,c}(m)+α_SRS,c·PL_c+f_c(i) dBm, min { x, y } is a minimum function that yields a number_xThe smaller of y, log₁₀(x) Is a base-10 logarithmic function that produces a base-10 logarithm, P, of the number x_CMAX,c(i) Is the transmit power in time point i, M, configured by higher layers for cell c_SRS,cIs the SRS Transmission Bandwidth, P, in time Point i and over cell c_{O_SRS,c}(m) is configured by a higher layer for cell c, when SRS transmission is configured by the higher layer, m is 0, and when SRS transmission is configured by DCI format, m is 1, PL_cIs a pathloss value, α, measured on cell c_SRS,cIs configured by higher layers for SRS transmission on cell c, and f_c(i) Is a transmit power control adjustment state, determined from TPC commands in the DCI format for SRS transmission in time point i and on cell c.

In yet another example, f_c(0)＝ΔP_rampup,c+δ_SRS,c，ΔP_rampup,c＝min[{max(0,P_CMAX,c-(10log₁₀(M_SRS,c)+P_{O_SRS,c}(m)+α_SRS,c·PL_c))},ΔP_{rampuprequested,c}]Max { x, y } is a maximum function that yields the greater of the numbers x, y, M_SRS,cIs the SRS bandwidth, Δ P, at the point in time of the first SRS transmission on cell c_{rampuprequested,c}Is the total power transmitted from the first to the last random access preamble on cell c, ramping up the power and configured by higher layers, and δ_SRS,cIs the value of the TPC command in the DCI format.

In yet another example, a Power Headroom (PH) report for SRS transmission in time point i and on cell c is determined as PH_c(i)＝P_CMAX,c(i)-{10log₁₀(M_SRS,c(i))+P_{O_SRS,c}(m)+α_SRS,c·PL_c+f_c(i)}。

According to various embodiments, a User Equipment (UE) comprises: a receiver configured to receive a Downlink Control Information (DCI) format that schedules reception of a data Transport Block (TB) and triggers transmission of a Sounding Reference Signal (SRS); and a transmitter configured to transmit the SRS and the acknowledgement information received in response to the data TB. When the SRS transmission will overlap in time with the acknowledgement information transmission, the UE is configured to defer the transmission of the SRS.

In one example, the acknowledgement information transmission is on a first cell, the SRS transmission is on a second cell, and the UE cannot transmit on the first cell and on the second cell simultaneously.

In another example, the SRS transmission is deferred to a first next point in time configured by higher layers for the SRS transmission.

Fig. 3B illustrates an example eNB 102, in accordance with some embodiments of the present disclosure. The embodiment of eNB 102 shown in fig. 3B is for illustration only, and the other enbs of fig. 1 can have the same or similar configurations. However, enbs are in a wide variety of configurations, and fig. 3B does not limit the scope of the disclosure to any particular implementation of an eNB. Note that eNB101 and eNB 103 can include the same or similar structure as eNB 102.

As shown in fig. 3B, the eNB 102 includes multiple antennas 370 a-370 n, multiple RF transceivers 372 a-372 n, Transmit (TX) processing circuitry 374, and Receive (RX) processing circuitry 376. In certain embodiments, one or more of the plurality of antennas 370 a-370 n comprises a 2D antenna array. The eNB 102 also includes a controller/processor 378, a memory 380, and a backhaul or network interface 382.

RF transceivers 372 a-372 n receive incoming RF signals, such as signals transmitted by UEs or other enbs, from antennas 370 a-370 n. RF transceivers 372 a-372 n down-convert incoming RF signals to generate IF or baseband signals. The IF or baseband signal is sent to RX processing circuitry 376, which generates a processed baseband signal by filtering, decoding, and/or digitizing the baseband or IF signal. The RX processing circuitry 376 transmits the processed baseband signals to the controller/processor 378 for further processing.

TX processing circuitry 374 receives analog or digital data (such as voice data, network data, e-mail, or interactive video game data) from controller/processor 378. TX processing circuitry 374 encodes, multiplexes, and/or digitizes the outgoing baseband data to generate a processed baseband or IF signal. RF transceivers 372a through 372n receive outgoing processed baseband or IF signals from TX processing circuitry 374 and upconvert the baseband or IF signals to RF signals for transmission via antennas 370a through 370 n.

The controller/processor 378 can include one or more processors or other processing devices that control overall operation of the eNB 102. For example, the controller/processor 378 can control the reception of forward channel signals and the transmission of reverse channel signals by the RF transceivers 372 a-372 n, the RX processing circuitry 376, and the TX processing circuitry 374 in accordance with well-known principles. The controller/processor 378 can also support additional functions, such as more advanced wireless communication functions. For example, the controller/processor 378 can perform a Blind Interference Sensing (BIS) process, such as by a BIS algorithm, and decode the received signal with the interference signal subtracted. The controller/processor 378 may be capable of supporting any of a wide variety of other functions in the eNB 102. In some embodiments, controller/processor 378 includes at least one microprocessor or microcontroller.

Controller/processor 378 is also capable of executing programs and other processes resident in memory 380, such as a base OS. The controller/processor 378 can also support sounding reference signal transmission using carrier aggregation as described in embodiments of the present disclosure. In some embodiments, the controller/processor 378 supports communication between entities, such as a network RTC. Controller/processor 378 can move data in and out of memory 380 as needed to perform processes.

Controller/processor 378 is also coupled to a backhaul or network interface 382. The backhaul or network interface 382 allows the eNB 102 to communicate with other devices or systems via a backhaul connection or via a network. Interface 382 is capable of supporting communication via any suitable wired or wireless connection. For example, when eNB 102 is implemented as part of a cellular communication system (such as a cellular communication system supporting 5G, LTE or LTE-a), interface 382 can allow eNB 102 to communicate with other enbs via a wired or wireless backhaul connection. When eNB 102 is implemented as an access point, interface 382 can allow eNB 102 to communicate via a wired or wireless local area network or via a wired or wireless connection to a larger network, such as the internet. Interface 382 includes any suitable structure that supports communication via a wired or wireless connection, such as an ethernet or RF transceiver.

The memory 380 is coupled to the controller/processor 378. A portion of memory 380 can include RAM and another portion of memory 380 can include flash memory or other ROM. In some embodiments, a plurality of instructions (such as a BIS algorithm) are stored in memory. The plurality of instructions are configured to cause the controller/processor 378 to perform a BIS process and decode the received signal after subtracting at least one interfering signal determined by a BIS algorithm.

As described in more detail below, the transmit and receive paths of the eNB 102 (implemented using the RF transceivers 372 a-372 n, the TX processing circuitry 374, and/or the RX processing circuitry 376) support communication using an aggregation of FDD and TDD cells.

Although fig. 3B illustrates one example of an eNB 102, various changes may be made to fig. 3B. For example, eNB 102 can include any number of each of the components shown in fig. 3. As a particular example, the access point can include a number of interfaces 382 and the controller/processor 378 can support routing functions for routing data between different network addresses. As another particular example, although illustrated as including a single instance of TX processing circuitry 374 and a single instance of RX processing circuitry 376, the eNB 102 can include multiple instances of each (such as one per RF transceiver).

According to various embodiments, a base station comprises: a transmitter configured to transmit a Downlink Control Information (DCI) format comprising a plurality of bit blocks, wherein a bit block comprises only a positive number of bits for a Transmit Power Control (TPC) command and a plurality of bits for a Sounding Reference Signal (SRS) request; and a receiver configured to receive an SRS having a power adjusted based on a value of the TPC command in the first bit block. When the number of bits for the SRS request in the first bit block is a positive number, SRS reception is performed in response to the value of the SRS request, and when the number of bits for the SRS request in the first bit block is zero, SRS reception is performed in response to a configuration made by a higher layer.

In one example, the TPC commands are only applicable to adjusting SRS transmit power.

In another example, a first bit block from the plurality of bit blocks is suitable for SRS transmission on a first cell and a second bit block from the plurality of bit blocks is suitable for SRS transmission on a second cell.

In yet another example, the DCI format size is equal to a size of a second DCI format including only a second TPC command, and the TPC command from the second TPC command is used to adjust a transmit power of a channel transmitting data information.

In yet another example, the SRS is received on a cell where the base station does not receive the SRS from the same transmitter and the channel on which the data information is transmitted.

In yet another example, the SRS is received from multiple groups of antennas of the transmitter at multiple respective points in time.

According to various embodiments, a base station comprises: a transmitter configured to transmit a Downlink Control Information (DCI) format that schedules transmission of a data Transport Block (TB) and triggers transmission of a Sounding Reference Signal (SRS); and a receiver configured to receive the SRS and the acknowledgement information for the data TB. When the SRS reception is to overlap in time with the acknowledgement information reception, the base station is configured to defer the reception of the SRS.

In one example, the SRS reception is deferred to a first next point in time configured for SRS reception.

A communication system includes a Downlink (DL) for transmitting signals from a transmission point (such as a base station or eNB) to a UE and an Uplink (UL) for transmitting signals from the UE to a reception point (such as an eNB). The UE (also commonly referred to as a terminal or mobile station) may be fixed or mobile and may be a cellular telephone, a personal computer device, or an automated device. An eNB (which is typically a fixed station) may also be referred to as an access point or other equivalent terminology.

The DL signal includes a data signal conveying information content, a control signal conveying DL Control Information (DCI), and a Reference Signal (RS), also referred to as a pilot signal. The eNB transmits data information or DCI through a corresponding Physical DL Shared Channel (PDSCH) or Physical DL Control Channel (PDCCH). The PDCCH can be enhanced PDCCH (epddch), but the term PDCCH will be used for brevity to denote PDCCH or EPDCCH. The PDCCH is transmitted via one or more Control Channel Elements (CCEs). The eNB transmits one or more of a plurality of types of RSs, including UE-common RS (crs), channel state information RS (CSI-RS), and demodulation RS (dmrs). The CRS is transmitted over the DL system Bandwidth (BW) and can be used by the UEs to demodulate data or control signals or perform measurements. To reduce CRS overhead, the eNB can transmit CSI-RS in the time and/or frequency domain with less density than CRS. For channel measurement, non-zero power CSI-RS (NZP CSI-RS) resources can be used. For Interference Measurement Reporting (IMR), a zero power CSI-RS (ZP CSI-RS) resource associated CSI interference measurement (CSI-IM) resource [3] can be used. The CSI process is composed of NZP CSI-RS and CSI-IM resources. DMRSs are transmitted only in BW of the corresponding PDSCH, and the UE can demodulate information in the PDSCH using the DMRSs.

The UL signal also includes a data signal transmitting information content, a control signal transmitting UL Control Information (UCI), and an RS. The UE transmits data information or UCI through a corresponding Physical UL Shared Channel (PUSCH) or Physical UL Control Channel (PUCCH). The UE can multiplex both data information and UCI in the PUSCH when the UE transmits both simultaneously, or transmit data and some UCI in the PUSCH and the remaining UCI in the PUCCH when the eNB configures the UE for simultaneous PUSCH and PUCCH transmission. The UCI includes hybrid automatic repeat request acknowledgement (HARQ-ACK) information indicating correct or incorrect detection of data Transport Blocks (TBs) in the PDSCH, Scheduling Requests (SRs) indicating whether the UE has data in its buffer, and CSI enabling the eNB to select appropriate parameters for link adaptation for transmission to the PDSCH or PDCCH of the UE.

The CSI includes a Channel Quality Indicator (CQI) that informs the eNB of the DL signal-to-interference-and-noise ratio (SINR) experienced by the UE, a Precoding Matrix Indicator (PMI) that informs the eNB of how to apply beamforming for DL transmissions to the UE, and a Rank Indicator (RI) that informs the eNB of the rank for PDSCH transmissions. UL RSs include DMRSs and sounding RSs (srs). The UE transmits DMRS only in BW of the respective PUSCH or PUCCH, and the eNB can demodulate information in the PUSCH or PUCCH using the DMRS. The UE transmits SRS to provide UL CSI to the eNB. SRS transmissions from a UE can be periodic (P-SRS, or trigger type 0SRS) or aperiodic (a-SRS, or trigger type 1SRS), as triggered by an SRS request field included in the DCI format scheduling a PUSCH or PDSCH transmitted by the PDCCH.

A Transmission Time Interval (TTI) for DL transmission or for UL transmission is called a Subframe (SF) and includes two slots. A unit of ten SFs is called a system frame. The system frame is identified by a System Frame Number (SFN) ranging from 0 to 1023 and can be represented by 10 binary elements (or bits). The BW unit for DL transmission or for UL transmission is called a Resource Block (RB), one RB on one slot is called a Physical RB (PRB), and one RB on one SF is called a PRB pair. Each RB is composed ofA number of subcarriers or Resource Elements (REs). REs are identified by an index pair (k, l), where k is the frequency domain index and l is the time domain index. The eNB informs parameters for PDSCH transmission to the UE orParameters for PUSCH transmission from a UE, the DCI format having a CRC scrambled by a cell radio network temporary identifier (C-RNTI), the DCI format being transmitted in a PDCCH transmitted by an eNB to the UE and being referred to as DL DCI format or UL DCI format, respectively.

Fig. 4 shows a PUSCH transmission structure.

The SF 410 includes two slots. Each slot 420 includes a transmitter for transmitting data information, UCI, or RSA symbol 430. Some PUSCH symbols in each slot are used to transmit DMRS 440. Each RB comprisesOne RE, and the UE is allocated M_PUSCHRB 450 s, totalThe number of REs is used for PUSCH transmission BW. The last SF symbol can be used to multiplex SRS transmissions 460 from one or more UEs. The number of SF symbols available for data/UCI/DMRS transmission isWherein N is the last SF symbol used to transmit SRS_SRS1 and otherwise, N_SRS＝0。

Fig. 5 illustrates a transmitter block diagram for data information and UCI in PUSCH according to some embodiments of the present disclosure.

Multiplexer 520 multiplexes encoded CSI symbols 505 and encoded data symbols 510. Multiplexer 530 then inserts the encoded HARQ-ACK symbols by puncturing the data symbols and/or CSI symbols. The transmission of the encoded RI symbols is similar to the transmission used for the encoded HARQ-ACK symbols (not shown). DFT is obtained through a Discrete Fourier Transform (DFT) unit 540, a selector 555 selects REs 550 corresponding to PUSCH transmission BW, an Inverse Fast Fourier Transform (IFFT) unit 560 performs IFFT, a filter 570 filters the output and a Power Amplifier (PA)580 applies a certain power thereto, and then a signal is transmitted 590. Additional transmitter circuitry for the data symbols and UCI symbols, such as digital-to-analog converters, filters, amplifiers, and transmitter antennas, as well as encoders and modulators, are omitted for simplicity.

Fig. 6 illustrates a receiver block diagram for data information and UCI in PUSCH according to some embodiments of the present disclosure. The embodiment of the receiver block diagram shown in fig. 6 is for illustration only. Other embodiments can be used without departing from the scope of this disclosure.

Filter 620 filters received signal 610, Fast Fourier Transform (FFT) unit 630 applies FFT, selector unit 640 selects REs 650 used by the transmitter, Inverse Dft (IDFT) unit applies IDFT 660, demultiplexer 670 extracts the encoded HARQ-ACK symbols and places erasures in the corresponding REs for the data symbols and CSI symbols, and finally, another demultiplexer 680 separates encoded data symbols 690 from encoded CSI symbols 695. Reception of the encoded RI symbols is similar to reception used for the encoded HARQ-ACK symbols (not shown). For simplicity, additional receiver circuitry for the data and UCI symbols, such as a channel estimator, demodulator, and decoder, is not shown.

DMRS or SRS transmissions can be made through transmission of respective Zadoff-chu (zc) sequences. For theUL system BW of individual RBs, can be determined byBase sequence of (1)Cyclic Shift (CS) alpha to define a sequenceWhereinIs the length of the sequence and is,and isWherein the q-th root ZC sequence consists ofIs defined wherein q is represented byGiving out andbyIt is given. Length of ZC sequenceGiven by the maximum prime number, such thatMultiple RS sequences can be defined from a single base sequence using different values of a.

Fig. 7 illustrates an example transmitter structure for ZC sequences according to some embodiments of the present disclosure. The embodiment of the transmitter structure shown in fig. 7 is for illustration only. Other embodiments can be used without departing from the scope of this disclosure.

Has a length ofZC sequences of REs 710 are mapped to REs transmitting BW by mapper 720 as indicated by RE selection unit 730. The mapping can be performed to consecutive REs for DMRS or to every other RE for SRS, creating a comb spectrum with a repetition factor of two (or every fourth RE for a repetition factor of four, etc.). Then IFFT filteringThe IFFT is performed by the 740, the CS mapper 750 applies the CS to the output, and the filter 760 filters the resulting signal. The power amplifier 770 applies transmit power and transmits RS 780.

Fig. 8 illustrates an example receiver structure for ZC sequences, according to some embodiments of the present disclosure. The embodiment of the receiver structure for ZC sequences shown in figure 8 is for illustration only. Other embodiments can be used without departing from the scope of this disclosure.

Filter 820 filters the received signal 810, CS demapper 830 recovers the CS, filter 840 applies an FFT, RE demapper 850 selects the RE indicated by controller 860 of the receive BW, complex multiplier 870 correlates the resulting signal with a replica 880 of the ZC sequence, and can then provide an output 890 to a channel estimator, such as a time-frequency interpolator.

Table 1 below provides a number of combinations for SRS transmission BW. The eNB can signal the cell specific SRS BW configuration c through system information. For example, 3 bits can indicate one of the eight configurations in table 1. The eNB can then assign an SRS transmission BW to each UE by indicating the value of b for the SRS BW configuration c(in RB). For P-SRS, this can be done by higher layer signaling of 2 bits. For a-SRS, this can be done by dynamically indicating the corresponding DCI format from one of a set of BWs configured to the UE through higher layer signaling. The variation of the maximum SRS BW is primarily intended to avoid varying total BW allocation for PUCCH transmissions at both edges of the UL BW. The eNB can also signal the cell-specific SRS transmission SF through system information.

Table 1: forUL BW of one RBAn RB value of

SRS BW configuration	b＝0	b＝1	b＝2	b＝3
					c＝0	96	48	24	4
c＝1	96	32	16	4
					c＝2	80	40	20	4
c＝3	72	24	12	4
					c＝4	64	32	16	4
c＝5	60	20	Not applicable to	4
					c＝6	48	24	12	4
c＝7	48	16	8	4

The UE transmits SRS on per-cell SRS resources based on trigger type 0 when SRS transmission is triggered by higher layer signaling, or based on trigger type 1 when SRS transmission is triggered by detection of DCI format 0/4/1a for FDD and TDD and DCI format 2B/2C/2D for TDD. The SRS request field has a size of 1 bit for DCI formats 0/1a/2B/2C/2D, where type 1SRS is triggered when the value of the SRS request field is set to "1". The SRS request field has a size of 2 bits for DCI format 4, and the mapping for the two bits can be as in table 2. In the case where both trigger type 0 and trigger type 1SRS transmissions will occur in the same SF and in the same cell, the UE transmits only trigger type 1 SRS. The transmission parameters for triggering type 0SRS or triggering type 1SRS are cell specific and are configured by higher layers to the UE. For brevity, the trigger type 0SRS will be referred to as periodic SRS (P-SRS), and the trigger type 1SRS will be referred to as aperiodic SRS (a-SRS). The higher layer configuration can be UE-specific through Radio Resource Control (RRC) signaling or cell-specific through system information signaling.

TABLE 2SRS request values for trigger type 1 in DCI Format 4

Value of SRS request field	Description of the invention
		“00”	No triggering type 1SRS
“01”	1 st SRS parameter set configured by higher layers
		“10”	2 nd SRS parameter set configured by higher layers
“11”	3 rd SRS parameter set configured by higher layers

In a TDD communication system, the communication direction is in the DL in some SFs and in the UL in some other SFs. Table 3 provides an indicative TDD UL-DL configuration over a period of one system frame. "D" denotes DL SF, "U" denotes UL SF, and "S" denotes a special SF including a DL transmission region called DwPTS, a Guard Period (GP), and an UL transmission region called uplink pilot time slot (UpPTS). There are several combinations for the duration of each region in a particular SF subject to the condition that the total duration is one SF.

TABLE 3 TDD UL-DL configurations

In TDD, upon detecting a positive SRS request in SF n of cell c, a UE configured for a-SRS transmission on cell c transmits SRS in a first SF that satisfies the following conditions: n + k, k ≧ 4, and for T_SRS,1>2，(10·n_f+k_SRS-T_offset,1)modT_SRS,10 or for T_SRS,1＝2，(k_SRS-T_offset,1) mod5 ═ 0, where k is_SRSIn table 4 or as defined in table 4A.

TABLE 4. k for TDD for UpPTS length of 2 symbols or 1 symbol_SRS

Table 4a. k for TDD with UpPTS of 4 symbols_SRS

In a TDD cell, an eNB configures an A-SRS periodic T to a UE_SRS,1And A-SRS SF offset T_offset,1As defined in table 5.T is_SRS,1Is cell specific and is selected from the set 2,5,10 SF. For T_SRS,1Two SRS resources are configured in a half frame containing the UL SF of a given cell, 2 SFs.

TABLE 5 UE-specific periodic T for A-SRS in TDD_SRS,1And SF offset configuration T_offset,1

One mechanism for meeting the demand for increased network capacity and data rates is network densification. This is achieved by deploying small cells in order to increase the number of network nodes and their proximity to the UE and to provide cell splitting gain. As the number of small cells increases and the deployment of small cells becomes dense, the handover frequency and handover failure rate may also increase significantly. By maintaining an RRC connection with the macro cell, communication with the small cell can be optimized for control plane (C-plane) functionality, such as mobility management, paging, and system information updates can be provided only by the macro cell, while the small cell can be dedicated to user data plane (U-plane) communication. If the latency of the backhaul link between network nodes (cells) is almost zero, Carrier Aggregation (CA) can be used as in REF 3 and scheduling decisions can be made by a central entity and communicated to each network node. When the propagation delays for UE transmissions are different for different cells, the cells can be grouped according to the propagation delays, and each group can be associated with a different Timing Advance Group (TAG) command.

Fig. 9 is a diagram illustrating communications using CA according to some embodiments of the present disclosure. The embodiment shown in fig. 9 is for illustration only. Other embodiments can be used without departing from the scope of this disclosure.

UE 910 communicates with a first eNB in one cell 920 corresponding to a macro cell using a first carrier frequency f 1930 and communicates with a second eNB in a second cell 940 corresponding to a small cell via a carrier frequency f 2950. The first eNB and the second eNB are connected via a backhaul that introduces negligible latency. It is also possible that the first eNB and the second eNB are the same eNB and that the first cell and the second cell correspond to different carrier frequencies.

The UE monitors PDCCH transmissions that provide UE-common information from the eNB in a Common Search Space (CSS). In case of CA, the CSS is located in one cell called primary cell (PCell). The UE transmits PUCCH in PCell. The eNB can also configure PUCCH transmissions to the UE for UCI associated with a group of cells in a primary secondary cell (PSCell). A cell group having associated UCI transmission on PUCCH of PCell is referred to as a Primary Cell Group (PCG), and a cell group having associated UCI transmission on PUCCH of PSCell is referred to as a Secondary Cell Group (SCG). Unless explicitly mentioned otherwise, the following description applies to both PCG and SCG, but for the sake of brevity, the differences between PCG and SCG or PCell and PSCell are not taken into account.

UE transmit power P of SRS transmitted in SF i for cell c_SRSIs as defined in equation 1:

P_SRS,c(i)＝min{P_CMAX,c(i),P_{SRS_OFFSET,c}(m)+10log₁₀(M_SRS,c)+P_{O_PUSCH,c}(1)+α_c(1)·PL_c+f_c(i)}[dBm](equation 1)

Wherein:

P_CMAX,c(i) is the configured UE transmit power in SF i for cell c;

P_{SRS_OFFSET,c}(m) is configured by higher layers for cell c for P-SRS (m ═ 0) and for a-SRS (m ═ 1);

M_SRS,cSRS transmission BW in SF i for cell c expressed in number of RBs;

when a higher layer implements a Transmit Power Control (TPC) command delta for cell c_PUSCH,c(i-K_PUSCH) During accumulation of (c), f_c(i)＝f_c(i-1)+δ_PUSCH,c(i-K_PUSCH) And when the higher layer does not implement the TPC command delta for cell c_PUSCH,c(i-K_PUSCH) During accumulation of (c), f_c(i)＝δ_PUSCH,c(i-K_PUSCH) Wherein δ_PUSCH,c(i-K_PUSCH) Is a TPC command, where the UE is provided with DCI format 3/3A with CRC scrambled by TPC-PUSCH-RNTI, where the UE is configured by higher layers, and DCI format 3 includes a TPC command represented by 2 bits, and DCI format 3A includes a TPC command represented by 1 bit; and is

P_{O_PUSCH,c}(1) And alpha_c(1) Is configured by higher layers for PUSCH transmission in cell c, where P_{O_PUSCH,c}(1) Is the sum of the cell-specific component and the UE-specific component (see also REF 3).

For UL transmissions via multiple antenna ports (PUSCH, PUCCH, SRS), the transmit power is first scaled by the ratio of the number of antenna ports to the number of antenna ports used for UL transmissions. The resulting scaled power is then split equally across the antenna ports of the UL transmission.

When the total UE transmit power for SRS will exceedUE for cell c in SF iScaling is performed such that the following condition in equation 2 is satisfied:

and w (i) is for cell cA scaling factor of (1), wherein 0<w (i) is less than or equal to 1. The w (i) values are the same across cells.

A UE configured for A-SRS transmission in cell c and not configured with a Carrier Indicator Field (CIF) transmits an A-SRS in cell c upon detecting a positive SRS request in a PDCCH that schedules PUSCH/PDSCH on the serving cell c. A UE configured for a-SRS transmission in cell c and configured with CIF transmits SRS in cell c upon detecting a positive SRS request in the PDCCH scheduling PUSCH/PDSCH with CIF value corresponding to cell c.

The UE can provide a Power Headroom (PH) report to the eNB in order for the eNB to obtain an estimate of the available power for UL transmission at the UE. For example, type 1PH reporting when the UE transmits PUSCH in SF i but not PUCCH for cell c is as defined in equation 3:

PH_type1,c(i)＝P_CMAX,c(i)-{10log₁₀(M_PUSCH,c(i))+P_{O_PUSCH,c}(1)+α_c(1)·PL_c+Δ_TF,c(i)+f_c(i)}[dB](equation 3)

When the UE does not transmit PUSCH in SF i for cell c, type 1PH report (virtual PH report) is as defined in equation 4 below, where calculation is as described in REF 3

For TDD systems, DL transmissions and UL transmissions are on the same BW, and thus DL transmissions from eNB to UE and UL transmissions from UE to eNB experience the same channel. Thus, the eNB can obtain the PMI for the UE (for DL beamforming using channel reciprocity) from receiving SRS transmissions from the UE. In addition, while the interference experienced at the UE for DL transmissions from the eNB can be different than the interference experienced at the eNB for UL transmissions from the UE, because the eNB and UE are not collocated, there can be operating conditions when similar interference is observed. In such cases, the SRS transmission can also provide CQI estimates for the DL transmission, since the SRS transmission also already provides channel response estimates. For example, for a UE in close proximity to an eNB and for similar enbs and UE heights, such as when the eNB and UE are located indoors or when the eNB and UE are located outdoors but the eNB height is relatively low, the UE and eNB can experience similar interference.

Due to data traffic patterns, UE complexity aspects, and conventional requirements related to transmission, which tend to be larger in the DL than in the UL, CA-capable UEs typically support or are configured to support a much smaller number of UL cells than DL cells. For example, a UE can be configured with CA operation with more than five DL cells and with only one or two UL cells. In such cases and for TDD systems, the UE is unable to transmit SRS to the eNB in some DL cells, and therefore, in order to enable link adaptation for DL transmission from the eNB to the UE, the UE needs to measure and report CSI, including CQI, PMI and RI, to the eNB for the DL cells. This increases UE computational complexity, memory requirements, and power consumption, and also increases the overhead of UL transmissions to include CSI feedback for a potentially large number of DL cells.

Fast carrier switching is considered for SRS transmission so that the UE is able to transmit SRS even in cells where the UE is configured for DL transmission but not configured for UL transmission. Such functionality presents a new set of design issues, including:

a) a mechanism for determining SRS transmit power in a cell for which the UE is not configured for UL transmissions.

b) Mechanisms for providing PH reporting for cells in which the UE transmits SRS and the UE is not configured for other UL transmissions.

c) Prioritization of power allocation when a UE is configured to simultaneously transmit SRS in a cell where the UE is configured for UL transmissions and in a cell where the UE is not configured for other UL transmissions.

d) Mechanisms for providing timing for A-SRS transmissions from a UE in a cell in which the UE is not configured for other UL transmissions in order to avoid simultaneous transmission of A-SRS in the cell and PUSCH/PUCCH transmissions in other cells.

e) A mechanism for triggering a-SRS transmissions in cells where the UE is not configured for other UL transmissions.

Therefore, there is a need to provide mechanisms for determining SRS transmission power in cells where the UE is not configured for UL transmissions.

A PH report needs to be defined additionally for cells where the UE transmits SRS and the UE is not configured for other UL transmissions in the cell.

There is a further need to establish prioritization rules for power allocation for SRS transmissions when the UE is configured to simultaneously transmit SRS in cells where the UE is configured for other UL transmissions and in cells where the UE is not configured for UL transmissions.

There is a further need to provide mechanisms for timing of a-SRS transmissions from a UE in a cell in which the UE is not configured for other UL transmissions in order to avoid simultaneous transmission of a-SRS in that cell and PUSCH/PUCCH transmissions in other cells.

In addition, there is a need to provide mechanisms for triggering a-SRS transmissions in cells where the UE is not configured for other UL transmissions.

In the following, reference UEs transmit P-SRS or a-SRS in TDD cells in which the UE is configured or not configured for other UL transmissions, unless explicitly mentioned otherwise.

SRS transmit power control

Various embodiments of the present disclosure contemplate mechanisms for implementing power control of SRS transmissions from a UE in a cell in which the UE is not configured for other UL transmissions in the cell.

In equation 1, the power for P-SRS transmission or for a-SRS transmission is defined with respect to the power for PUSCH transmission. In cell c, where the UE transmits P-SRS or A-SRS and the UE does not have PUSCH transmission, the power control parameters derived from the PUSCH transmission power for P-SRS transmission or for A-SRS transmission need to be separately configured from the eNB to the UE by higher layers. These parameters include P_{SRS_OFFSET,c}(m)、P_{O_PUSCH,c}(1) And alpha_c(1). In addition, the eNB needs to configure TPC commands to the UE for P-SRS transmission or A-SRS transmission in cell c. In addition, the eNB needs to configure P for c to the UE through a higher layer_CMAX,c(i) The value is obtained.

In equation 1, the eNB configures the UE with a parameter P in cell c through a higher layer_{O_PUSCH,c}(1) And a parameter P for offsetting a transmission power for P-SRS (m-0) or for a-SRS (m-1) with respect to a PUSCH transmission power_{SRS_OFFSET,c}(m) of the reaction mixture. The parameter P_{O_PUSCH,c}(1) With a cell-specific component and a UE-specific component (see also REF 3). For cell c for which the UE is not configured for other UL transmissions, a new parameter P is defined and configured to the UE by higher layers for P-SRS (m-0) transmissions and for a-SRS (m-1) transmissions_{O_SRS,c}(m) and does not require higher layers to configure the corresponding P_{O_PUSCH,c}(1) And P_{SRS_OFFSET,c}(m) a parameter. Like P_{O_PUSCH,c}(1)，P_{O_SRS,c}(m) can be a sum of the cell-specific component and the UE-specific component.

In a first approach, TPC commands for many cells where a UE is configured for P-SRS transmission or for a-SRS transmission can be provided by DCI format 3/3A with a CRC scrambled by a TPC-PUSCH-RNTI configured by higher layers to the UE. Transmitting the DCI format 3/3a through a PDCCH transmitted in a CSS of a cell that is a PCell for the UE. The TPC-PUSCH-RNTI can be the same as the TPC-PUSCH-RNTI configured to the UE for PUSCH transmissions, and the location of TPC commands for cells without PUSCH transmissions from the UE can be configured separately or be continuous and follow the location of TPC commands for cells with PUSCH transmissions.

In a second approach, the UE can be configured with a new RNTI type, i.e., TPC-SRS-RNTI, by higher layers and can monitor DCI format 3/3a (said DCI format 3/3a having a CRC scrambled with said TPC-SRS-RNTI) to obtain TPC commands for P-SRS or a-SRS transmissions in cells where the UE is not configured for other UL transmissions. The TPC-SRS-RNTI may be referred to as SRS-TPC-RNTI. According to various embodiments, the at least one transceiver of the UE is further configured to receive a message including an SRS-TPC-Radio Network Temporary Identifier (RNTI) from the base station via higher layer signaling and decode a PDCCH of the DCI with a Cyclic Redundancy Check (CRC) scrambled by the SRS-TPC RNTI. In one example, the PDCCH may be transmitted in a Common Search Space (CSS) according to the DCI format. The second approach can be beneficial to allow different transmission rates of TPC commands among PUSCH/SRS transmissions in cells where the UE is configured with PUSCH transmissions and SRS transmissions in cells where the UE is not configured for other UL transmissions. The second approach is also beneficial to maintain existing eNB implementations for DCI format 3/3a, which DCI format 3/3a has CRC scrambled by TPC-PUSCH-RNTI.

For cells in which the UE is configured to transmit P-SRS or a-SRS and the UE is not configured for other UL transmissions, the UE is provided with a parameter TPC-Index-SRS by a higher layer to indicate to the UE the position of bits in the DCI format 3/3a for the UE to obtain TPC commands for adjusting SRS transmit power in the cell. Upon detecting DCI format 3/3a with CRC scrambled by TPC-PUSCH-RNTI or TPC-SRS-RNTI, the UE applies TPC commands obtained from bits of DCI format 3/3a in the positions indicated by the parameter TPC-Index-SRS for cell c to adjust P-SRS transmit power or a-SRS transmit power in cell c. Hereinafter, the parameter TPC-Index-SRS may indicate a start bit position of a new DCI format with CRC scrambled by SRS-TPC-RNTI.

UE transmit power P for SRS transmitted in SF i for cell c where the UE is configured to transmit SRS only_SRS,c(i) Is as defined in equation 5 below:

P_SRS,c(i)＝min{P_CMAX,c(i),10log₁₀(M_SRS,c)+P_{O_SRS,c}(m)+α_SRS,c·PL_c+f_c(i)}[dBm](equation 5)

Wherein:

P_CMAX,c(i) is the maximum UE transmit power in SF i for cell c configured to the UE by the higher layer;

P_{O_SRS,c}(m) is configured to the UE through a higher layer;

M_SRS,cSRS transmission BW in SF i for cell c expressed in number of RBs;

when the higher layer implements the TPC command delta for cell c_PUSCH,c(i-K_PUSCH) During accumulation of (c), f_c(i)＝f_c(i-1)+δ_PUSCH,c(i-K_PUSCH) And when the higher layer does not implement the TPC command delta for cell c_PUSCH,c(i-K_PUSCH) During accumulation of (c), f_c(i)＝δ_PUSCH,c(i-K_PUSCH) Wherein δ_PUSCH,c(i-K_PUSCH) Is a DCI format 3/3a provides a TPC command to a UE, the DCI format 3/3a having a CRC scrambled by a TPC-PUSCH-RNTI or TPC-SRS-RNTI configured by higher layers to the UE, the TPC command being located at a position determined by a parameter TPC-Index-SRS configured by higher layers to the UE for a cell c; and is

α_SRS,cIs configured by higher layers for SRS transmission in cell c.

In different implementations, the structure of equation 1 can be maintained and parameter P can be introduced for cells where the UE is only configured with SRS transmission_{O_PUSCH,c}(1) And P_{SRS_OFFSET,c}(m) of the reaction mixture. Thus, equation 5 can be calculated by using P_{SRS_OFFSET,c}(m)+P_{O_PUSCH,c}(1) Replacement of P_{O_SRS,c}(m) is used. As a signalling optimization, the configuration of P by higher layers can be avoided_{O_PUSCH,c}(1) And instead use a value configured for another cell (such as Pcell P)_{O_PUSCH,c0}(1) As a reference value.

UE can set f_c(0) The initial transmit power is determined from equation 5 for P-SRS (type 0SRS) or a-SRS (type 1SRS) on a cell where the UE has no other configured transmission, and thus is determined using only the open loop component of the power control formula in equation 5. Alternatively, as described later, when the UE performs random access on a cell prior to SRS transmission, the determination for f can be based on a transmission power resulting in successful completion of random access_c(0) The value of (c).

The PH report for P-SRS transmission or a-SRS transmission in SF i for cell c is as calculated in equation 6. In one embodiment, the UE transmits a PH report for SRS transmission.

PH_type3,c(i)＝P_CMAX,c(i)-{10log₁₀(M_SRS,c(i))+P_{O_SRS,c}(m)+α_SRS,c·PL_c+f_c(i)}[dB](equation 6)

Since the same TPC commands are applied for P-SRS and A-SRS transmissions and the eNB knows P_{O_SRS,c}(0) And P_{O_SRS,c}(1) Difference between them, so a single PH report can be provided and it can refer to the use of P_{O_SRS,c}(0) Or use of P-SRS_{O_SRS,c}(1) A-SRS of (1).

When the UE does not transmit P-SRS or A-SRS in SF i for cell c, the PH report is calculated as in equation 7, where P &iscalculated as described in REF 3_CMAX,c(i) In that respect As for equation 6, we can refer to P_{O_SRS,c}(0) Or P_{O_SRS,c}(1) A PH report is provided.

When the total UE transmit power for SRS will exceedWhen, the same weight of 0 is used instead of the UE<w (i ≦ 1 for cell c in SF iScaling so that a condition is satisfiedIn a first method, the UE prioritizes power allocation for P-SRS transmissions or A-SRS transmissions in cells in which the UE is also configured for other UL transmissions, and the UE discards P-SRS transmissions or A-SRS transmissions, respectively, in cells in which the UE is not configured for other UL transmissions. This is because SRS transmissions in cells where the UE is also configured for other UL transmissions can benefit both PDSCH and PUSCH link adaptation, while SRS transmissions in cells where the UE is not configured for other UL transmissions can benefit only PDSCH link adaptation.

In a second method, the UE prioritizes power allocation for P-SRS transmissions over other P-SRS transmissions or power allocation for a-SRS transmissions over other a-SRS transmissions in cells in which the UE is also configured for other UL transmissions, and the UE scales power of SRS transmissions in cells in which the UE is not configured for other UL transmissions, respectively, such that a condition is satisfiedWherein C is₁Is the set of cells that the UE is configured for other UL transmissions and the UE transmits either a P-SRS or an A-SRS in SF i, and C₂Is the set of cells that the UE is not configured for other UL transmissions and the UE transmits P-SRS or A-SRS in SF i. When in useThen, the UE discards C₂P-SRS or A-SRS transmission in a set of cells and pairing for C in SF i₁Of cell c in the set of cellsScaling is performed so that the condition is satisfiedA-SRS transmissions in cells where the UE is not configured for other UL transmissions are prioritized over P-SRS transmissions in cells where the UE is configured for other UL transmissions in terms of power allocation.

Timing for A-SRS transmission

Various embodiments of the present disclosure contemplate mechanisms for defining timing for a-SRS transmissions.

For cells where the UE is not configured for other UL transmissions, the a-SRS transmission is triggered by a DL DCI format (such as DL DCI format 1A/2B/2C/2D) that also schedules the transmission of data TBs to the UE. It is then possible that in the same SF, the UE will need to transmit HARQ-ACK information in cells (PCell or PSCell) where the UE is configured for PUCCH transmissions and a-SRS transmissions in cells where the UE is not configured for other UL transmissions. Then, especially when the number of cells in which the UE is able to have simultaneous UL transmissions in the SF is small (such as 1 or 2), which cannot transmit both SRS and HARQ-ACK when exceeding the UE capability for simultaneous UL transmissions on different cells, the UE will prioritize HARQ-ACK transmissions on e.g. PCell or PSCell and discard a-SRS transmissions in cells in which the UE is not configured for other UL transmissions. Since support for a-SRS transmission in a cell for which the UE is not configured for other UL transmissions is mainly beneficial for TDD UL-DL configurations with many DL SFs and a small number of UL SFs (heavy DL TDD UL-DL configurations), the UE may often be unable to transmit a-SRS.

In a first method, at least when the UE needs to drop a-SRS transmissions because the UE cannot simultaneously transmit in the first cell and in the second cell, the timing for a-SRS transmissions from the UE in the first cell that the UE is not configured for other UL transmissions can be adjusted depending on whether the a-SRS transmissions coincide with PUSCH/PUCCH transmissions in the second cell. Thus, for A-SRS transmissions triggered by DL DCI formats transmitted in SF n, the UE transmits A-SRS in the first SF, which satisfies n + k, k ≧ 4 and (10 · n)_f+k_SRS-T_offset,1)modT_SRS,1＝0(T_SRS,1>2) Or (k)_SRS-T_offset,1)mod5＝0(T_SRS,12) and further satisfies that the UE does not drop the a-SRS transmission. In other words, in one embodiment, the UE determines that the first subframe n + k is satisfied, k ≧ 4 k without HARQ-ACK for more than one serving cell.

Fig. 10 illustrates timing for a-SRS transmissions from a UE in a cell in which the UE is not configured for other UL transmissions, in accordance with some embodiments of the present disclosure. The embodiment shown in fig. 10 is for illustration only. Other embodiments can be used without departing from the scope of this disclosure.

Cells for which the UE is not configured with UL transmissions other than SRS transmissions use TDD UL-DL configuration 2. For SRS transmission in the cell, the UE is configured to correspond to T_SRS,12 and T_offset,11, 2I_SRS2. The UE detects a DCI format triggering an a-SRS transmission in SF n 31010. When the UE is capable of transmitting a-SRS based on the UE capability for the total number of UL transmissions in the corresponding number of cells, the UE transmits a-SRS in SF n 71020. When the UE is unable to transmit an a-SRS in SF n + 4-7 based on the UE capability for the total number of UL transmissions in the corresponding number of cells, the UE transmits the a-SRS in special SF n-11030 of the next frame, assuming that the special SF n-1 includes two or more UpPTS symbols.

A first method relies on the ability of the eNB to receive A-SRS transmissions from the UE to determine whether the UE is transmitting the A-SRS. For example, such capability may be needed if the UE fails to detect a subsequent DL DCI format or UL DCI format, which would result in the UE transmitting a PUCCH or PUSCH in the first SF in the second cell and further cause the UE to defer or drop a-SRS transmission in the first SF in the first cell. Such ambiguity can also exist for P-SRS transmissions and can be caused by a UE failing to detect a DL DCI format or a UL DCI format, which thus causes the UE to erroneously transmit a PUCCH or PUSCH and the UE to drop the P-SRS transmission because the UE cannot transmit simultaneously in multiple cells.

In a second approach, to avoid the need for the eNB to determine whether the UE transmits an a-SRS (or P-SRS), the a-SRS transmission in cells where the UE is not configured for other UL transmissions can always be in the UpPTS of the special SF. This can also accommodate re-tuning latency, depending onIn the associated value for the retune latency, since the GP of a particular SF can be used to return to the carrier of SRS transmission and the last UpPTS symbol or the first symbol of the next SF can be used to retune to another carrier. In a first example, the A-SRS transmission is always in the first special SF that satisfies n + k, k ≧ 4. In case that the UpPTS includes more than one symbol, the UpPTS symbol for a-SRS transmission (or P-SRS transmission) can be configured to the UE through a higher layer or determined for the UE from the C-RNTI. For example, for N_UpPTSA UpPTS symbol, the UE can determine the index of the UpPTS symbol for A-SRS transmission as n_C-RNTImodN_UpPTSWherein n is_C-RNTIIs the C-RNTI for the UE. In addition, the number of UpPTS symbols where the UE transmits the a-SRS can be configured to the UE through a higher layer. In a second example, the a-SRS SF offset value can be modified as in table 6. For T_SRS,12 or T_SRS,1No SRS configuration index needs to be provided in case of one UpPTS symbol in a special SF 5.

Table 6: UE-specific SRS periodicity T for A-SRS in TDD_SRS,1And SF offset configuration T_offset,1。

In a third method, when the UE is configured to transmit a P-SRS or an a-SRS in a SF in a first cell and the UE is further configured to transmit a PUSCH or PUCCH in the SF in a second cell and beyond the UE capability for many cells with simultaneous transmissions, the UE can be configured whether to puncture/suspend the PUSCH or PUCCH transmission in SF symbols in the second cell, where the UE transmits the P-SRS or the a-SRS in the first cell or drops the P-SRS or the a-SRS transmission. For example, when configured, the UE suspends PUCCH or PUSCH transmission in the last SF symbol in the second cell, and the UE transmits P-SRS or A-SRS in the last SF symbol in the first cell. Suspending PUCCH or PUSCH transmission in the last SF symbol in the second cell is applicable even in SFs not configured for SRS transmission in the second cell or even when PUSCH/PUCCH transmission does not overlap in BW with the cell-specific maximum SRS transmission BW in the second cell. For PUCCH format 2 transmission, system operation can provide for the UE to drop SRS transmission or PUCCH format 2 transmission when the UE defaults not to puncture the last SF symbol.

Fig. 11 illustrates puncturing of a last SF symbol for PUSCH or PUCCH transmission in a second cell for transmission of SRS in a first cell in accordance with some embodiments of the present disclosure. The embodiment shown in fig. 11 is for illustration only. Other embodiments can be used without departing from the scope of this disclosure.

The UE transmits PUSCH or PUCCH in the second cell and SRS in the first cell in the same SF. The eNB configures the UE to suspend PUSCH or PUCCH transmission in the last SF symbol and transmits SRS in cells where the UE is not configured with other UL transmissions. The UE suspends PUSCH or PUCCH transmission in the last SF symbol 1110 in the second cell and the UE transmits SRS in the first cell 1120.

When the retuning latency is large enough for a UE to retune from a PUCCH transmitted carrier to an SRS transmitted carrier before the PUCCH transmission is completed (that is, before the SF ends) or for a UE to retune from an SRS transmitted carrier to a PUCCH transmitted carrier after the PUCCH transmission is started (that is, after the SF starts), orthogonal multiplexing of PUCCH transmissions from the UE and PUCCH transmissions from other UEs in the time domain using orthogonal cover codes across each slot of the SF is not possible, especially when different UEs require different retuning latencies depending on their capabilities.

To maintain the ability of orthogonal multiplexing of PUCCH transmissions on the same PRB pair regardless of retuning latency, and to avoid near-far effects on received PUCCHs transmitted from different UEs, the multiplexing can be limited by excluding orthogonal multiplexing in the time domain only in the cyclic shift domain by using different Orthogonal Cover Codes (OCCs). The resulting resource allocation and corresponding PUCCH transmitter and receiver structure is described in REF 6 with respect to a low cost UE capable of transmitting in only a small part of the system BW. In general, the exclusion of orthogonal multiplexing can be applied to any type of application.

A-SRS transmission triggering

Various embodiments of the present disclosure contemplate mechanisms for triggering a-SRS transmissions.

In a first approach, a-SRS transmissions from a UE in a cell without other UL transmissions from the UE are configured by only DL DCI formats (such as DL DCI formats 1A/2B/2C/2D) transmitted by PDSCH in the scheduling cell. The UL DCI format configures a-SRS transmission only in the cell transmitting the associated PUSCH.

In a second approach, the eNB can configure UE-common RNTI (SRS-RNTI) for a group of UEs to the UEs for scrambling a CRC of a UE-common DCI format that triggers a-SRS transmission. This may enable the eNB to trigger an a-SRS transmission from a group of UEs without transmitting a corresponding DL DCI format to schedule an associated PDSCH transmission to the group of UEs, and may enable the eNB to obtain CSI information prior to scheduling (or not scheduling) a PDSCH transmission to UEs in the group of UEs. The UE can be configured to share more than one location in the DCI format by the UE, the location corresponding to a respective a-SRS trigger indication for one or more respective configured cells, which may include either or both of cells that the UE is configured for PUSCH transmission and cells that the UE is not configured for PUSCH transmission. The UE can be configured with more than one SRS-RNTI corresponding to SRS triggering in more than one respective group of one or more cells.

The eNB configures SRS-RNTI for scrambling CRC of DCI format to the UE. For example, the DCI format can have the same size as DCI format 0/1a or DCI format 3/3 a. This can avoid increasing the number of PDCCH decoding operations that the UE needs to perform in the SF. The eNB also configures an Index-SRS to the UE for the UE to determine the position of an A-SRS trigger bit for the UE in the DCI format. The number of a-SRS trigger bits can be predetermined in system operation or configured to the UE. For example, the number of SRS trigger bits can be one for a UE with one transmitter antenna, and two for a UE with more than one transmitter antenna. The UE can be configured with multiple positions of a-SRS trigger bits for a corresponding number of cells, where the position for each cell can be determined, for example, according to an ascending order of cell indices or configured separately for each cell. For example, for 16 UEs in a UE group, for a DCI format comprising 32 bits, and for 2 bits used to trigger a-SRS transmission in a cell, the eNB can configure the fifth and sixth bits as a-SRS trigger bits to the UEs by setting the value of the Index-SRS Index to indicate the third pair of bits. For example, for 4 UEs in the UE group, for a DCI format comprising 32 bits, and for 2 bits for triggering a-SRS transmission in a cell, the eNB can configure the second eighth bit to the UE as an a-SRS trigger bit for four configured cells by setting the value of the Index-SRS Index to indicate the second eight bits.

The multiple TPC command bits for SRS transmission can also be included in a UE common DCI format with a CRC scrambled by the SRS-RNTI. The number of TPC command bits can be the same for each UE and can be defined in system operation, such as two bits as in DCI format 3 or one bit as in DCI format 3A. Then, in the DL SF or the special SF, or at a predetermined DL SF or special SF according to the a-SRS transmission periodicity, the UE can attempt to detect the UE common DCI format and determine whether the UE should transmit an a-SRS in a corresponding cell, determine a corresponding set of parameters in case of a-SRS transmission in a cell, and determine a TPC command for adjusting the transmission power of the a-SRS or the P-SRS in the cell.

In a first example, the number of TPC command bits used for a-SRS transmission from the UE can be consecutive to the number of bits configuring a-SRS transmission from the UE. In a second example, the TPC command bits can be located after the a-SRS transmission trigger bits for all UEs, and each UE can derive the location of the TPC command bits based on the location of the a-SRS trigger bits. For example, for 8 UEs in the UE group, a DCI format is common to UEs including 32 bits, and for 2 bits for triggering a-SRS transmission in a cell and 2 bits for a TPC command, a UE configured with the fifth and sixth bits as a-SRS trigger bit can determine that the TPC command bit is the seventh bit of the eight bits according to the first example or the twenty-first and twenty-second bits according to the second example. For example, for 4 UEs in the UE group, for a DCI format comprising 32 bits, and for 2 bits for triggering a-SRS transmission in a cell and 2 bits for a TPC command, the eNB can configure the second eighth bit to the UE as an a-SRS trigger bit and a TPC command bit for two configured cells by setting the value of the Index-SRS Index to indicate the second eight bits. The order of the a-SRS trigger bits and TPC command bits can also be exchanged. The same method can be applied to the UE determining the position of the TPC command for SRS transmission in the respective cell in DCI format 3/3a (said DCI format 3/3a having a CRC scrambled by TPC-SRS-RNTI).

Fig. 12 illustrates content of a DCI format with a CRC scrambled by an SRS-RNTI indicating whether a UE transmits an a-SRS in a cell, in accordance with some embodiments of the present disclosure. The embodiment shown in fig. 12 is for illustration only. Other embodiments can be used without departing from the scope of this disclosure.

The eNB configures to the UE the SRS-RNTI for the UE-common DCI format and the position 1210 of the A-SRS trigger bit in the cell in the UE-common DCI format. The eNB determines the UEs from the UE group to trigger the respective a-SRS transmission in the SF 1220. The eNB sets the value of the bit 1230 according to whether the eNB triggers an a-SRS transmission from the UE. For example, for two bits associated with a cell, the eNB sets a value of "00" when the eNB does not trigger a-SRS transmission from a UE in the cell, and sets a value other than "00" when the eNB triggers a-SRS transmission from a UE in the cell, according to a configuration of values corresponding to the two bits. The eNB transmits DCI format 1240 with CRC scrambled by SRS-RNTI.

The UE receives SRS-RNTI for the UE common DCI format from the eNB and a configuration 1250 for the position of the bit in the UE common DCI format associated with triggering an a-SRS transmission from the UE in the cell. The UE detects the UE-common DCI format 1260 with CRC scrambled by SRS-RNTI. The UE obtains the value 1270 of the a-SRS trigger bit. When the value of the A-SRS trigger bit is '00', the UE does not transmit an A-SRS in the cell, and when the value of the A-SRS trigger bit is not '00', the UE transmits the A-SRS in the corresponding cell according to the parameter corresponding to the value of the A-SRS trigger bit. The example in fig. 12 assumes that the UE is configured for a single cell for SRS transmission.

Fig. 13 illustrates content of a DCI format with a CRC scrambled by an SRS-RNTI indicating whether a UE transmits an a-SRS in a cell and indicating TPC commands for the UE to apply to SRS transmit power, in accordance with some embodiments of the present disclosure. The embodiment shown in fig. 13 is for illustration only. Other embodiments can be used without departing from the scope of this disclosure.

The eNB configures to the UE an SRS-RNTI for the UE-common DCI format, a position in the UE-common DCI format of a bit associated with an a-SRS transmission from the UE in a trigger cell, and a TPC command 1310 for the UE to determine an SRS transmit power adjustment. The eNB determines that the UEs from the group of UEs trigger respective a-SRS transmissions and determines corresponding TPC commands for power adjustment 1320. The eNB sets a value 1330 of an a-SRS trigger bit (e.g., a block of a-SRS trigger bits) according to whether the eNB triggers an a-SRS transmission from the UE in the cell. The eNB transmits a DCI format 1340 with CRC scrambled by SRS-RNTI.

The UE receives from the eNB SRS-RNTI for the UE common DCI format and a configuration 1350 of TPC commands for respective power adjustments and locations in the UE common DCI format for bits associated with a-SRS transmissions from the UE in a triggering cell. The UE detects a UE-common DCI format 1360 with a CRC scrambled by the SRS-RNTI. The UE obtains values 1370 for a-SRS trigger bits (e.g., a-SRS trigger bit block) and TPC command bits (e.g., TPC command bit block). When the value of the a-SRS trigger bit is "00", the UE does not transmit an a-SRS in the cell, and when the value of the a-SRS trigger bit is not "00", the UE transmits an a-SRS 1380 in the cell using the power adjustment determined from the TPC command and according to the parameter corresponding to the value of the bit. The parameters are configured by higher layers from the eNB for the value of the bits or determined in the system operation. The UE is able to process TPC commands even when the UE is not triggered a-SRS transmission. The example in fig. 13 assumes that the UE is configured for a single cell for SRS transmission.

Since there is no UL DCI format for configuring a-SRS transmissions from a UE in a cell with no other UL transmissions, only a single configuration for a-SRS transmissions is possible because there is only a single bit in the DL DCI format to indicate whether the UE transmits a-SRS. For UEs with multiple transmitter antennas, this implies that there is no flexibility to dynamically determine the set of UE antenna ports for a-SRS transmission, and this set needs to be indicated by higher layers. For example, there is no flexibility for the eNB to dynamically configure whether the UE transmits a-SRS using 1 or 2 antenna ports in the case of two UE transmitter antenna ports or 1,2 or 4 antenna ports in the case of four UE transmitter antenna ports. Furthermore, there is no flexibility to dynamically configure BW for a-SRS transmission. This is disadvantageous especially in case of multiple UE transmitter antenna ports, since the UE may not be able to transmit SRS from all antenna ports simultaneously and as power for SRS transmission, which may typically be less than the maximum available transmit power in case the UE has also other UL transmissions, needs to be divided equally between the UE transmitter antenna ports, and it can often be preferred that the a-SRS transmission BW is less than the maximum in order to achieve a sufficiently large power spectral density for the a-SRS transmission.

The above-described limitations of dynamically configuring parameters for a-SRS transmission can be mitigated by enabling dynamic configuration of a set of parameters for a-SRS transmission or by enabling configuration for a-SRS transmission in multiple SFs along with frequency hopping. Dynamic configuration for parameter sets is achieved by increasing the number of SRS trigger bits in a DL DCI format from 1 bit to 2 or more bits when the UE is configured for a-SRS transmission in a cell with no other UL transmission or by using a new DCI format with a CRC scrambled by an SRS-RNTI that is capable of associating more than one bit with an a-SRS trigger in the respective cell. For example, in the case of 2 bits, the mapping to parameter configuration can be as in table 2. The SRS-RNTI may be referred to as SRS-TPC-RNTI.

According to various embodiments, an apparatus of a User Equipment (UE) configured with more than one serving cell for Time Division Duplexing (TDD) comprises at least one processor and at least one transceiver operatively coupled to the at least one processor. The at least one transceiver is configured to receive Downlink Control Information (DCI) using a DCI format including first information for Transmit Power Control (TPC) commands and second information for Sounding Reference Signal (SRS) requests, and transmit SRS based on the DCI.

According to various embodiments, an SRS is transmitted on a serving cell that is not configured for Physical Uplink Shared Channel (PUSCH)/Physical Uplink Control Channel (PUCCH) transmission.

According to various embodiments, the second information for the SRS request indicates whether the UE transmits an aperiodic SRS (a-SRS) in the serving cell. In some embodiments, when the second information for the SRS request indicates a positive number, the SRS is transmitted as an a-SRS in response to the second information, and when the second information for the SRS request indicates zero, the SRS is transmitted in response to a configuration made by a higher layer.

The eNB can configure the UE with a-SRS transmissions in multiple symbols of an SF or in multiple SFs from the same antenna port or from different antenna ports, at least when each SRS transmission is over a BW that is less than the maximum transmission BW as indicated by the eNB through the cell-specific SRS BW configuration in table 1. For example, when a-SRS transmissions are configured to be on half of the maximum transmission BW, the transmissions occur in two consecutive symbols of SF (such as a special SF), or in consecutive SFs and hopping occurs between the two halves of the maximum transmission BW. For example, when a UE has two antenna ports and cannot transmit SRS from both antenna ports simultaneously, SRS transmission can occur in two consecutive symbols of an SF (such as a special SF) or in consecutive SFs, and from a first antenna port in a first symbol and a second antenna port in a second symbol. In general, when an eNB configures a UE with a cellSRS of a number of RBs transmits BW and eNB indicates in a cellWhen the maximum SRS of the RBs transmits BW, the UE is inTransmitting A-SRS over multiple SFs, wherein in a constituent cellOf RBOf RBFrequency hopping occurs for each SRS transmission symbol in each of the plurality of SRS transmission BWs. Whether frequency hopping or transmission over multiple symbols or over multiple SFs is enabled can be configured to the UE by higher layers or can be associated with one parameter set when there are multiple parameter sets for an a-SRS transmission in case more than one bit is used for an a-SRS trigger in a cell.

It is also possible that a UE that is not configured with frequency hopping or multi-symbol a-SRS transmission transmits an a-SRS on the maximum SRS transmission BW. In a first example, the a-SRS transmission BW can be associated with transmitting an SF that triggers a DCI format for the a-SRS. For example, for the same value of the a-SRS trigger bit, the UE can transmit the a-SRS in the first BW when the UE detects the DCI format triggering the a-SRS in the SF with even indices, and can transmit the a-SRS in the second BW when the UE detects the DCI format triggering the a-SRS in the SF with odd indices. In a second example, in the case of more than one a-SRS trigger bit, a first value of the a-SRS trigger bit can be associated with a first set of parameters including a first a-SRS transmission BW or a first set of antenna ports, and a second value of the a-SRS trigger bit can be associated with a second set of parameters including a second a-SRS transmission BW or a second set of antenna ports.

Fig. 14 illustrates a-SRS transmission triggered by one DCI format in multiple SFs using frequency hopping, according to some embodiments of the present disclosure. The embodiment shown in fig. 14 is for illustration only. Other embodiments can be used without departing from the scope of this disclosure.

The eNB signals SRS BW configuration 31400 with a maximum SRS BW 1402 of 72 RBs through system information. There is no SRS transmission in the plurality of RBs in the system BW 1406, 1408. The UE is configured by higher layers to transmit an a-SRS via a first BW 1410 of 24 RBs in a first SF. The BW location for a-SRS transmission in the first SF can be configured to the UE by higher layers or can be predetermined, such as predetermined to include a BW of 24 RBs with a lower index. The eNB configures the UE, either by independent configuration or by indication of a set of parameters for a-SRS transmission, to transmit the a-SRS with frequency hopping over three SFs such that the maximum BW of 72 RBs is probed by the UE. The UE transmits an a-SRS in the 24 RBs 1420 with the largest index in the second SF, and transmits an a-SRS in the middle 24 RBs 1430 in the third SF from 72 RBs.

When a cell in which the UE is configured to transmit SRS and the UE is not configured for any other UL transmission requires a different TAG than any of the cells in which the UE is also configured for other UL transmissions, the UE should also be able to transmit a Random Access (RA) preamble in a Physical Random Access Channel (PRACH) in the cell in response to a PDCCH order from the eNB in order for the eNB to issue an appropriate Timing Advance (TA) value to the UE for SRS transmissions in the cell by means of a Random Access Response (RAR). Therefore, it is possible that a UE configured to transmit SRS only in a cell needs to also support PRACH transmission in the cell. In such cases, when the UE needs to suspend transmission depending on the total number of UE capabilities used for transmissions in different cells in the same SF, the UE can prioritize PRACH transmissions in that cell over other transmissions in other cells than PRACH transmissions. The need for PRACH transmission in a cell in which the UE is otherwise configured only for SRS transmission (that is, the UE is not configured for PUSCH/PUCCH transmission) can be avoided by restricting the cell to belong to the same TAG as the cell in which the UE is configured for PUSCH/PUCCH transmission.

After the UE transmits PRACH on cell c, the UE can determine the initial power of SRS transmission for carrier switching as follows.

First SF i 0, f for SRS transmission on cell c_c(0)＝ΔP_rampup,c+δ_SRS,cWherein δ_SRS,cIs a TPC command in DCI format 3/3A (where CRS is scrambled with SRS-RNTI), Δ P_rampup,c＝min[{max(0,P_CMAX,c-(10log₁₀(M_SRS,c)+P_{O_SRS,c}(m)+α_SRS,c·PL_c))},ΔP_{rampuprequested,c}]，M_SRS,cIs the bandwidth of the first SRS transmission, and Δ P_{rampuprequested,c}Are provided by higher layers and correspondThe total power ramp up from the first to the last RA preamble on cell c required by higher layers. δ SRS transmission for carrier switching not associated with an associated DCI format with CRC scrambled with SRS-RNTI_SRS,c0. In other words, in one embodiment, f_c(0)＝ΔP_rampup,c。

The present disclosure enables SRS transmissions from a UE in cells where the UE is not configured for other UL transmissions. The present disclosure provides a power control mechanism for SRS transmissions in cells where the UE is not configured for UL transmissions. The disclosure also provides for definition of PH reports for cells in which the UE transmits SRS and the UE is not configured for other UL transmissions in the cell. The present disclosure additionally provides prioritization rules for power allocation for SRS transmissions when the UE is configured to simultaneously transmit SRS in cells where the UE is configured for other UL transmissions and in cells where the UE is not configured for Uplink (UL) transmissions. The present disclosure further provides mechanisms for timing a-SRS transmissions from a UE in a cell in which the UE is not configured for other UL transmissions in order to avoid simultaneous transmission of a-SRS in the cell and Physical UL Shared Channel (PUSCH)/Physical UL Control Channel (PUCCH) transmissions in other cells. The present disclosure provides mechanisms for triggering a-SRS transmissions in cells where the UE is not configured for other UL transmissions.

Any other terms including, but not limited to, "mechanism," "module," "device," "unit," "component," "element," "member," "device," "machine," "system," "processor," or "controller" used in the claims are understood by the applicant to refer to structure known to those of skill in the relevant art.

Although the present disclosure has been described using exemplary embodiments, various changes and modifications may be suggested to one skilled in the art. The present disclosure is intended to embrace such alterations and modifications as fall within the scope of the appended claims.