Uplink control information processing method and user equipment

Abstract

A method and user equipment (UE) for transmitting uplink control information (UCI) via the physical uplink control channel (PUCCH) is proposed. UCI can include different information and is sent using different PUCCH formats. In some scenarios, the size of the encoded UCI bit stream does not fit into an integer number of modulation symbols. To eliminate unnecessary processing and utilize every bit in the modulated resource element, the UCI codeword size should be adjusted to a multiple of the PUCCH modulation order.

Description

[0001] Cross-references

[0002] The present invention claims the benefit of priority to U.S. patent application Ser. No. 62 / 616,528, filed on January 12, 2018, entitled “OnNR UL Processing”; and U.S. provisional patent application Ser. No. 62 / 620,505, filed on January 23, 2018, entitled “On NR UL Processing”, both of which are hereby incorporated by reference. Technical Field

[0003] Embodiments of the present invention generally relate to wireless communications, and more particularly, to methods and apparatus for uplink control information (UCI) processing in new radio (NR) systems. Background Art

[0004] Wireless communication networks have grown exponentially over the years. Long-Term Evolution (LTE) systems offer high peak data rates, low latency, improved system capacity, and low operating costs due to a simple network architecture. LTE systems, also known as 4th Generation (4G) systems, also provide seamless integration with older networks, such as Global System for Mobile Communications (GSM), Code Division Multiple Access (CDMA), and Universal Mobile Telecommunications System (UMTS). In LTE systems, the evolved universal terrestrial radio access network (E-UTRAN) consists of multiple evolved Node-Bs (eNodeBs or eNBs) that communicate with multiple mobile stations called user equipment (UE). The 3rd Generation Partnership Project (3GPP) is a non-profit organization that provides a comprehensive and integrated mobile communications solution for the 3rd Generation Partnership Project (3GPP). rd5G New Radio (NR) systems.

[0005] Due to its stability to multipath fading, better spectrum efficiency and bandwidth scalability, Orthogonal Frequency Division Multiple Access (OFDMA) has been selected for the LTE / NR downlink (DL) wireless access scheme. Multiple access to the downlink can be achieved by allocating different subbands of the system bandwidth (e.g., groups of subcarriers represented as resource blocks (RBs)) to each user based on the user's existing channel conditions. In LTE / NR networks, the physical downlink control channel (PDCCH) can be used for downlink scheduling. The physical downlink shared channel (PDSCH) can be used for downlink data. Similarly, in the uplink, the physical uplink control channel (PUCCH) can be used to carry UCI. The physical uplink shared channel (PUSCH) can be used for uplink data.

[0006] In the OFDMA-based 3GPP LTE / NR system, radio resources are divided into subframes or time slots in the time domain, and each subframe / time slot includes multiple OFDM symbols. Depending on the system bandwidth, each OFDMA symbol is further composed of multiple OFDMA subcarriers in the frequency domain. The basic unit of the resource grid is called a resource element (RE), which spans the OFDMA subcarriers on the OFDMA symbol. Multiple REs are divided into physical resource blocks (PRBs), where each PRB includes twelve consecutive subcarriers in a time slot. In principle, the coded UCI bits are assigned to an integer number of modulated REs for PUCCH transmission. However, the UCI codeword size may not be a multiple of the PUCCH modulation order. Therefore, unnecessary processing is required at the base station and dummy bits are inserted on the UE side.

[0007] A solution needs to be found. Summary of the Invention

[0008] A method for UCI transmission via PUCCH is proposed. UCI may include different information and be sent using different PUCCH formats. In some scenarios, the coded UCI bit stream size is not allocated to an integer number of modulation symbols. In order to eliminate unnecessary processing and utilize every bit in the modulated resource element, the UCI codeword size should be adjusted to a multiple of the PUCCH modulation order. In one embodiment, the UCI includes a first bit stream of channel state information (CSI) part 1 and a second bit stream of CSI part 2. The first bit stream and the second bit stream are modulated and mapped separately and independently. The codeword size of the first UCI bit stream is adjusted to a multiple of the PUCCH modulation order. The sum of the first UCI codeword size and the second UCI codeword size is equal to the predefined total codeword size allocated to PUCCH transmission.

[0009] In one embodiment, the UE encodes UCI in the NR network. The UCI is encoded as a first UCI bit stream having a first UCI codeword size and a second UCI bit stream having a second UCI codeword size. The UE adjusts the first UCI bit stream so that the first UCI codeword size is a multiple of the modulation order. The UE modulates the adjusted first UCI bit stream using a modulation scheme with a modulation order and maps it to multiple REs, wherein the modulation scheme is binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), or quadrature amplitude modulation (QAM). The UE sends UCI through the PUCCH.

[0010] The uplink control information processing method and user equipment of the present invention can eliminate unnecessary processing.

[0011] Other embodiments and advantages are described in the detailed description that follows. This summary is not intended to define the invention. The invention is defined by the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The accompanying drawings depict embodiments of the present invention, wherein like numerals represent like parts.

[0013] Figure 1 A system diagram of an NR wireless system for UCI transmission via PUCCH according to an embodiment of the present invention is described.

[0014] Figure 2 A simplified block diagram of a UE and a base station (BS) implementing an embodiment of the present invention is shown.

[0015] Figure 3 This article describes the UCI transmission on the PUCCH in the NR system that carries different UCI contents with different UCI codeword sizes.

[0016] Figure 4 Embodiments for determining a suitable UCI codeword size for PUCCH in a NR network according to novel aspects of the present disclosure are described.

[0017] Figure 5 is a flowchart of a method for transmitting UCI through PUCCH according to an embodiment of the present invention. DETAILED DESCRIPTION

[0018] Reference will now be made in detail to some embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

[0019] Figure 1 A system diagram of an NR wireless system for UCI transmission via PUCCH in accordance with an embodiment of the present invention is described. The NR wireless system 100 is an OFDM / OFDMA system including an infrastructure unit 101 and multiple user equipments UE 102, UE 103, and UE 104. Each infrastructure unit forms a wireless radio access network (RAN) distributed over a geographical area. The infrastructure unit 101 may also refer to an access point (AP), an access terminal, a BS, a Node-B, an eNodeB / eNB, a next generation Node-B (gNodeB / gNB), or other terms used in the art. Each UE may be a smartphone, a wearable device, an Internet of Things (IoT) device, a tablet computer, or the like. In an OFDMA-based LTE / NR system, radio resources are divided into radio frames and subframes, each of which consists of a time slot and an OFDM symbol in the time domain. Depending on the system bandwidth, each OFDMA symbol is further composed of multiple OFDMA subcarriers in the frequency domain. The basic unit of the resource grid is called RE, which spans OFDMA subcarriers on an OFDMA symbol. REs are grouped into PRBs, where each PRB includes 12 consecutive subcarriers in one slot.

[0020] When there is a downlink packet to be sent from the eNodeB to the UE, each UE receives a downlink allocation, for example, a set of radio resources in the PDSCH. When the UE needs to send a packet to the eNodeB in the uplink, the UE receives a grant from the eNodeB, which allocates a PUSCH consisting of a set of uplink radio resources. The UE receives downlink or uplink scheduling information from the PDCCH, which is specific to the UE. In addition, broadcast control information is also sent to all UEs in the cell on the PDCCH. The downlink or uplink scheduling information and broadcast control information carried by the PDCCH are called downlink control information (DCI). UCI includes Hybrid Automatic ReQuest (HARQ) acknowledgment / negative acknowledgment (ACK / NACK), channel quality indicator (CQI), multiple-input multiple-output (MIMO) feedback and scheduling request (SR). UCI is carried by the PUCCH.

[0021] exist Figure 1 In the example shown in FIG, PUCCH / PUSCH 120 is allocated to UE 102 for UCI. PUCCH / PUSCH 130 is allocated to UE 103 for UCI. PUCCH / PUSCH 140 is allocated to UE 104 for UCI. PUCCH / PUSCH 120, PUCCH / PUSCH 130, and PUCCH / PUSCH 140 form different radio resource interleavings in the entire frequency domain. Similarly, multiple radio resource interleavings on the nominal channel bandwidth with interleaved PRBs can be allocated to the UE as PUSCH. For UCI transmission via PUCCH, the UCI is first encoded, rate matched, and scrambled. The encoded UCI bits are then modulated to create complex-valued modulation symbols based on various modulation orders. Finally, the complex-valued modulation symbols are mapped to corresponding REs of the PRB for OFDM signal transmission.

[0022] In principle, the coded UCI bits are assigned to an integer number of modulated REs for PUCCH transmission, and every bit in the modulated RE should be used. However, the UCI codeword size may not be a multiple of the PUCCH modulation order. Therefore, unnecessary processing needs to be performed at the base station and dummy bits need to be inserted on the UE side. For example, the UE needs to insert dummy bits before performing modulation, and in order to correctly decode the UCI, the base station needs to discard an unassigned bit at the boundary of the QPSK RE. According to a novel aspect, in order to eliminate unnecessary processing and utilize every bit in the modulated RE, it is recommended to adjust the UCI codeword size so that it is always a multiple of the PUCCH modulation order (step 110).

[0023] Figure 2 A simplified block diagram of a wireless device 200 (e.g., UE 201 and base station 211) implementing an embodiment of the present invention is described. The base station 211 has an antenna or antenna array 217 that transmits and receives radio signals. A radio frequency (RF) transceiver 216 is coupled to the antenna or antenna array 217, receives RF signals from the antenna or antenna array 217, converts them to baseband signals, and sends them to the processor 213. The RF transceiver 216 also converts baseband signals received from the processor 213, converts them to RF signals, and sends them to the antenna or antenna array 217. The processor 213 processes the received baseband signals and calls different functional modules to perform functions in the base station 211. The memory 212 stores program instructions and data 220 to control the operation of the base station 211. In Figure 2In the example of , the base station 211 also includes a set of control modules and circuits, such as a decoder and demodulator circuit 215 for decoding and demodulating received OFDM signals, a scheduler 214 for scheduling UEs for downlink reception and uplink transmission, an OFDMA circuit 219 for processing OFDM signals and RE mapping, and a configuration and control circuit 231 for providing coding and modulation parameters.

[0024] Similarly, UE 201 has an antenna or antenna array 207 that transmits and receives radio signals. RF transceiver 206 is coupled to antenna or antenna array 207, receives RF signals from antenna or antenna array 207, converts them to baseband signals, and transmits them to processor 203. RF transceiver 206 also converts baseband signals received from processor 203, converts them to RF signals, and transmits them to antenna or antenna array 207. Processor 203 processes the received baseband signals and invokes various functional modules and circuits to perform functions within UE 201. Memory 202 stores program instructions and data 210 to control the operation of UE 201. Suitable processors include, but are not limited to, special purpose processors, digital signal processors (DSPs), multiple microprocessors, one or more microprocessors associated with a DSP core, controllers, microcontrollers, application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), and other types of integrated circuits (ICs), and / or state machines.

[0025] UE201 also includes a set of control modules and circuits that perform functional tasks. These functions can be implemented by software, firmware, hardware and / or any combination thereof. When the functional modules and circuits are executed by processor 203 (for example, by executing program instructions and data 210), UE201 is allowed to perform embodiments of the present invention. The functional features of UE 201 can be implemented and configured using a processor associated with the software. For example, encoder 205 encodes UCI bits into codewords, modulator 204 modulates the encoded UCI bits into modulation symbols, OFDMA circuit 209 maps the modulation symbols to REs, and transmits them as OFDM signals via PUCCH. Configuration and control circuit 221 receives configuration information for coding and modulation parameters and adjusts the UCI bit stream codeword size to a multiple of the PUCCH modulation order so that the UCI bit stream is mapped to an integer number of modulated REs.

[0026] Figure 3Describes UCI transmission on PUCCH in the NR system that carries different UCI content, where the different UCI content has different UCI codeword sizes. PUCCH carries a set of information called UCI (uplink control information). Depending on the type of information that UCI carries in PUCCH, PUCCH is divided into different formats, which can be summarized as follows. HARQ-ACK uses PUCCH format 1a or 1b. HARQ-ACK uses PUCCH format 1b with channel selection. SR uses PUCCH format 1. HARQ-ACK and SR use PUCCH format 1a or 1b. CQI uses PUCCH format 2. CQI and HARQ-ACK use PUCCH format 2a or 2b as a normal cyclic prefix, and use PUCCH format 2 as an extended cyclic prefix. PUCCH format 3 carries longer HARQ-ACK, optionally with SR and CSI report. PUCCH format 4 carries longer UCI bits, including HARQ-ACK, SR (if any) and periodic CSI report (if any). PUCCH format 5 carries more than one CSI report and SR (if any).

[0027] Figure 3 Table 310 describes the UCI codeword size E transmitted via PUCCH according to UCI content and PUCCH format. UCI For UCI transmission via PUCCH, the UCI is first coded, rate matched, and scrambled. The coded UCI bits are then modulated to create complex-valued modulation symbols based on various modulation orders. Finally, the complex-valued modulation symbols are mapped to the corresponding REs of the PRB for OFDM signal transmission. In principle, the coded UCI bits are assigned to an integer number of modulation REs for PUCCH transmission. However, the UCI codeword size E UCI It may not be the PUCCH modulation order Q m multiples of .

[0028] Specifically, the CSI feedback information consists of two parts, CSI Part 1 and CSI Part 2. When PUCCH is used to carry different CSI parts, the coded UCI bits are divided into two UCI bit streams to be transmitted. Each UCI bit stream should be mapped to an integer number of modulated REs for PUCCH transmission, thereby allowing parallel processing. If the UCI codeword size E UCI For any UCI bit stream, it is not the PUCCH modulation order Q m If the number of bits is a multiple of , unnecessary processing needs to be done on the base station side and dummy bits need to be inserted on the UE side. According to one novel aspect, the UE converts the E UCI Adjust to PUCCH modulation order Q m multiples of .

[0029] exist Figure 3 In the example of Table 310, eight different UCI transmission scenarios on PUCCH are described. In Table 310, the total codeword size of UCI transmission is represented as E tot , the UCI codeword size of each bitstream is expressed as E UCI For the first five scenarios, E UCI =E tot For scenarios 6, 7, and 8, E UCI They are listed as follows:

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036] in,

[0037] -O CSI-part1 The size of CSI Part 1;

[0038] -O CSI-part2 The size of CSI Part 2;

[0039] -O ACK is the size of HARQ-ACK;

[0040] -O SR is the size of SR;

[0041] -L is the cyclic redundancy check (CRC) size;

[0042] -R max UCI is the rate matching ratio;

[0043] -Q m is the modulation order.

[0044] For each UCI bit stream, the UCI codeword size of each bit stream can be adjusted to the PUCCH modulation order Q by performing an upper limit function mFor example, in UCI scenario 6, the first UCI bitstream includes CSI part 1, and the second UCI bitstream includes CSI part 2. The UCI codeword size of the first UCI bitstream is And the UCI codeword size of the second UCI bitstream is The sum of the first UCI codeword size and the second UCI codeword size is always equal to the total codeword size E allocated for UCI transmission through PUCCH tot .

[0045] Figure 4 An embodiment of determining a suitable UCI codeword size for PUCCH in NR networks according to novel aspects of the present invention is described. Consider PUCCH format 3, where UCI includes HARQ-ACK and CSI with CSI part 1 and CSI part 2. If N PUCCH，3 symb，UCI =12 (indicates the number of OFDM symbols used for PUCCH, excluding Demodulation Reference Signal (DMRS) symbols), N PUCCH，3 PRB =5 (representing the frequency range of 5 PRBs in every 12 PUCCH symbols, 5*12 REs of QPSK), Q m =2(QPSK modulation), R max UCI = 0.35 (rate matching ratio) and CRC size L = 11. Figure 4 As shown, if there are two UCI bit streams to be sent, the first bit stream #1 includes HARQ-ACK and CSI part 1, and the second bit stream #2 includes CSI part 2. In a specific example, bit stream #1 has a total of 384 information bits of HARQ-ACK+CSI-part 1, that is, ACK +O CSI-part1 =384. Bitstream #2 has a total of 72 bits, i.e., CSI-part2 = 72. After rate matching and CRC error checking, the required UCI codeword size for bitstream #1 = (384 + 11) / 0.35 = 1129, and the total available codeword size on the PUCCH = 24*12*5 = 1440.

[0046] Therefore, for bit stream #1, the UCI codeword size on the PUCCH using QPSK = min(1440, 1129) = 1129 (odd number), and for bit stream #2, the UCI codeword size on the PUCCH using QPSK = 1440-1129 = 311 (odd number). m=2, when UCI bit stream #1 with an odd number of bits is modulated onto REs based on QPSK, the number of modulation symbols will no longer be an integer (e.g., odd number / 2 = non-integer). In the prior art, if the UCI codeword size is not a multiple of the PUCCH modulation order, unnecessary processing is required at the base station and dummy bits are inserted on the UE side. In one example, the UE needs to insert dummy bits before performing modulation, and in order to correctly decode the UCI, the base station needs to discard an unspecified bit at the RE boundary. In another example, in addition to parallel mapping (step 412) to modulation symbols, coupled mapping (step 411) is also required. For example, as shown in step 411, the UE needs to pair some bits of bit stream #1 with some bits of bit stream 2 and perform coupled mapping for modulation and PUCCH transmission. For example, QPSK modulation and mapping require bits from bit streams #1 and #2 to generate the target total number of QPSK symbols. Therefore, QPSK modulation and mapping cannot be performed independently and separately, and the two bit streams are coupled together through PUCCH transmission, which introduces additional complexity at the receiving end.

[0047] On the other hand, according to the proposed UCI transmission scheme, the UCI bit stream 1 is adjusted to include multiple PUCCH modulation orders Q m To ensure that the modulation symbols are an integer and enable parallel processing, as shown in step 421. UCI The number of information bits in can be adjusted by using an upper bound operation, e.g., UCI Adjust to N UCI Upper limit divided by Q m Multiply by Q m In this way, it can be ensured that E UCI is the PUCCH modulation order Q m For QPSK modulation, the modulation order Q m =2. Therefore, the UCI codeword size of each UCI bitstream should be an even number. For example, if the E of bitstream #1 before adjustment UCI If the codeword size is odd, it can be adjusted and extended by 1 bit to become an even number. Therefore, the code rate of bit stream #1 will be lower due to the extended codeword size, and the code rate of bit stream #2 will be higher due to the simplified codeword size.

[0048] Figure 5This is a flowchart of a method for transmitting UCI via PUCCH in accordance with an embodiment of the present invention. In step 501, the UE encodes UCI in the NR network. The UCI is encoded into a first UCI bit stream having a first UCI codeword size and a second UCI bit stream having a second UCI codeword size. In step 502, the UE adjusts the first UCI bit stream so that the first UCI codeword size is a multiple of the modulation order. In step 503, the UE modulates the adjusted first UCI bit stream using a modulation scheme having the modulation order and maps it to multiple REs. In step 504, the UE transmits the UCI via the PUCCH.

[0049] Although the present invention has been described in conjunction with certain specific embodiments for instructional purposes, it is not limited thereto. Accordingly, various modifications, adaptations and combinations of the various features of the described embodiments may be implemented without departing from the scope of the invention as set forth in the claims.

Claims

1. A method for processing uplink control information, characterized in that: include: encoding, by a user equipment, uplink control information in a new radio network, wherein the uplink control information is encoded into a first uplink control information bit stream having a first uplink control information codeword size and a second uplink control information bit stream having a second uplink control information codeword size; Adjusting the first uplink control information bit stream so that a codeword size of the first uplink control information is a multiple of a modulation order, wherein the adjustment of the first uplink control information bit stream is to enable parallel processing between the first uplink control information bit stream and the second uplink control information bit stream; modulating the adjusted first uplink control information bit stream using a modulation scheme having the modulation order and mapping the modulated bit stream to a plurality of resource elements; and The uplink control information is sent through a physical uplink control channel.

2. The uplink control information processing method according to claim 1, wherein: The first uplink control information bit stream includes a first portion of channel state information.

3. The uplink control information processing method according to claim 1, wherein: The second uplink control information bit stream includes a second portion of the channel state information.

4. The uplink control information processing method according to claim 1, wherein: The first uplink control information bit stream and the second uplink control information bit stream are modulated and mapped, respectively.

5. The uplink control information processing method according to claim 1, wherein: The first uplink control information codeword size and the second uplink control information codeword size are added together to form a predefined total size of the physical uplink control channel.

6. The uplink control information processing method according to claim 1, wherein: The adjustment of the first uplink control information bit stream is to ensure that the number of modulation symbols of the first uplink control information bit stream is an integer.

7. The uplink control information processing method according to claim 1, wherein: The adjusting of the first uplink control information bit stream includes performing a capping operation.

8. The uplink control information processing method according to claim 1, wherein: The modulation scheme is binary phase shift keying, quadrature phase shift keying, or quadrature amplitude modulation.

9. A user equipment for uplink control information processing, characterized in that include: an encoder for encoding uplink control information in a new radio network, wherein the uplink control information is encoded into a first uplink control information bit stream having a first uplink control information codeword size and a second uplink control information bit stream having a second uplink control information codeword size; Configuration and control circuitry to adjust the first uplink control information bit stream so that a codeword size of the first uplink control information is a multiple of a modulation order, wherein the adjustment of the first uplink control information bit stream is to enable parallel processing between the first uplink control information bit stream and the second uplink control information bit stream; a modulator for modulating the adjusted first uplink control information bit stream using a modulation scheme having the modulation order; An orthogonal frequency division multiple access circuit maps the adjusted first uplink control information bit stream to a plurality of resource elements; and The radio frequency transceiver sends the uplink control information through a physical uplink control channel.

10. The user equipment according to claim 9, wherein: The first uplink control information bit stream includes a first portion of channel state information.

11. The user equipment according to claim 9, wherein: The second uplink control information bit stream includes a second portion of the channel state information.

12. The user equipment according to claim 9, wherein The first uplink control information bit stream and the second uplink control information bit stream are modulated and mapped, respectively.

13. The user equipment according to claim 9, wherein: The first uplink control information codeword size and the second uplink control information codeword size are added together to form a predefined total size of the physical uplink control channel.

14. The user equipment according to claim 9, wherein: The adjustment of the first uplink control information bit stream is to ensure that the number of modulation symbols of the first uplink control information bit stream is an integer.

15. The user equipment according to claim 9, wherein: The adjusting of the first uplink control information bit stream includes performing a capping operation.

16. The user equipment according to claim 9, wherein: The modulation scheme is binary phase shift keying, quadrature phase shift keying, or quadrature amplitude modulation.

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