Method and apparatus for multi-stream transmission

Abstract

The present disclosure relates to providing a pre-5th-Generation (5G) or 5G communication system to support higher data rates beyond 4th-Generation (4G) communication system such as Long Term Evolution (LTE). Methods and apparatuses for multi-stream transmission are provided. A user equipment (UE) includes a transceiver configured to receive an L-layer data transmission including at least one code block (CB). The CB includes a cyclic redundancy code (CRC) of length N. The transceiver is further configured to receive downlink control information (DCI) associated with the data transmission. The UE further includes a processor operably connected to the transceiver. The processor is configured to decode the data transmission, the CRC, and the DCI. The data transmission includes one codeword (CW) when L is less than or equal to a threshold value, and the data transmission includes two CWs when L is greater than the threshold value.

Description

[0001] This application is a divisional application of the patent application with application number 201780074585.3 and filing date 01 / 12 / 2017. TECHNICAL FIELD

[0002] The present disclosure relates generally to methods for multi-stream transmission. These methods can be used when a user equipment is equipped with multiple transmit antennas and transmit-receive units. BACKGROUND

[0003] To meet the demand for wireless data traffic having increased since deployment of 4thgeneration (4G) communication systems, efforts have been made to develop an improved 5thgeneration (5G) or pre-5G communication system. Therefore, the 5G or pre-5G communication system is also called a 'Beyond 4G Network' or a 'Post LTE System'.

[0004] The 5G communication system is considered to be implemented in a frequency band of 6 GHz or more, e.g., a millimeter wave (mmWave) band of 60 GHz or more, so as to accomplish higher data rates. To decrease propagation loss of the radio waves and increase the transmission distance, the beamforming, massive multiple-input multiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, an analog beam forming, large scale antenna techniques are discussed in 5G communication systems.

[0005] In addition, in 5G communication systems, development for system network improvement is under way based on enhanced small cells, cloud radio access networks (RANs), ultra-dense networks, a technology for coordination between cells, a cooperative multi-cell transmission scheme, an interference mitigation and cancellation, a network slicing, a 3D channel transmission technology, a mobile network-based Internet Protocol (IP) access (MN-IP), wireless backhaul, a mobile network-based Internet of Things (IoT), a mobile network-based V2X (vehicle-to-everything), and the like.

[0006] In 5G systems, hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC) have been developed as advanced coding modulation (ACM) techniques, and filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) have been developed as advanced access techniques.

[0007] Wireless communication is one of the most successful innovations in modern history. The demand for wireless data traffic is rapidly increasing due to the growing popularity of smart phones and other mobile data devices (e.g., tablets, "note pad" computers, net books, e-book readers, and machine-type devices) by consumers and businesses. To meet the high growth in mobile data traffic and support new applications and deployments, improvements in radio interface efficiency and coverage are essential.

[0008] Mobile devices or user equipment can measure the quality of a downlink channel and report the quality to a base station so that determinations can be made as to whether various parameters should be adjusted during communication with the mobile device. Existing channel quality reporting procedures in wireless communication systems are insufficient to accommodate reporting of channel state information associated with large two-dimensional array transmit antennas or generally applicable to antenna array geometries that accommodate a large number of antenna elements. SUMMARY

[0009] Various embodiments of the present disclosure provide methods and apparatuses for multi-stream transmission.

[0010] In one embodiment, a user equipment (UE) is provided. The UE includes a transceiver configured to receive an L-layer data transmission including at least one code block (CB). The CB includes a cyclic redundancy code (CRC) of length N. The transceiver is also configured to receive a downlink control information (DCI) associated with the data transmission. The UE also includes a processor operably connected to the transceiver. The processor is configured to decode the data transmission, CRC, and DCI. When L is less than or equal to a threshold, the data transmission includes one codeword (CW), and when L is greater than the threshold, the data transmission includes two CWs.

[0011] In another embodiment, a base station (BS) is provided. The BS includes a processor configured to generate an L-layer data transmission for a UE and generate a DCI associated with the data transmission. The data transmission includes at least one CB, and the CB includes a CRC of length N. The BS also includes a transceiver operably connected to the processor. The transceiver is configured to transmit the data transmission and DCI. When L is less than or equal to a threshold, the data transmission includes one CW, and when L is greater than the threshold, the data transmission includes two CWs.

[0012] In another embodiment, a method for operating a UE is provided. The method includes receiving an L-layer data transmission. The data transmission includes at least one CB, and the CB includes a CRC of length N. The method also includes receiving a downlink control information (DCI) associated with the data transmission and decoding the data transmission, CRC, and DCI. When L is less than or equal to a threshold, the data transmission includes one CW, and when L is greater than the threshold, the data transmission includes two CWs.

[0013] Other technical features can be readily apparent to one skilled in the art from the following figures, descriptions, and claims.

[0014] Before undertaking the detailed description below, it can be advantageous to set forth definitions of certain terms and phrases used in this patent document. The term “coupled” 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,” as well as derivatives thereof, means in connection with; included within; in communication with; containing; containing within; attached to or with; coupled to or with; containing or with; interoperable with; logically associated with; or some similar phrase. The term “controller” means any device, system or part thereof that controls at least one operation. Such a controller can be implemented in hardware or a combination of hardware and software and / or firmware. The functionality associated with any particular controller can be centralized or distributed, whether locally or remotely. The phrase “at least one of” followed by a list of two or more items, means that any of the listed items can be employed by itself, or in combination with one or more of the listed items. For example, “at least one of A and B” means A, B, or A and B.

[0015] Moreover, 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, procedures, functions, objects, classes, instances, related data, or a portion thereof applicable for implementation. 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 excludes wired, wireless, optical, or other communication links. Non-transitory computer readable media include media having physical storage such as RAM, ROM, hard drives, CDs, DVDs, or any other memory. The terms “non-transitory” and “transitory” are used herein to exclude only a transitory signal per se, such as a transitory propagating signal.

[0016] Definitions for other certain words and phrases are provided throughout this patent document. Those of ordinary skill in the art will understand that in many, if not most instances, such definitions apply to prior as well as future uses of such defined words and phrases. BRIEF DESCRIPTION OF DRAWINGS

[0017] For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings in which like parts are marked with like numerals throughout the drawings, in which:

[0018] Figure 1 An example wireless network is shown in accordance with various embodiments of the present disclosure;

[0019] Figure 2A And 2B An example wireless transmit and receive path is shown in accordance with various embodiments of the present disclosure;

[0020] Figure 3A An example user equipment is shown in accordance with various embodiments of the present disclosure;

[0021] Figure 3B An example BS is shown in accordance with various embodiments of the present disclosure;

[0022] Figure 4 An example beamforming architecture is shown in which one CSI-RS port is mapped onto a large number of analog control antenna elements;

[0023] Figure 5 Example embodiments for data transmission with spatial multiplexing are shown in accordance with embodiments of the present disclosure;

[0024] Figure 6 Example embodiments for CB segmentation are shown in accordance with embodiments of the present disclosure;

[0025] Figure 7A Example embodiments for symbol level layer mapping are shown in accordance with embodiments of the present disclosure;

[0026] Figure 7B Example embodiments for CB length dependent layer mapping are shown in accordance with embodiments of the present disclosure;

[0027] Figure 8 Example embodiments for CB level vertical layer mapping are shown in accordance with embodiments of the present disclosure;

[0028] Figure 9A Example embodiments for rank dependent layer mapping with codeword (CW) cycling for higher ranks are shown in accordance with embodiments of the present disclosure;

[0029] Figure 9B Example embodiments for CW cycling are shown in accordance with embodiments of the present disclosure;

[0030] Figure 10An example embodiment for bit-level and symbol-level processing is shown according to embodiments of the present disclosure;

[0031] Figure 11 An example embodiment for bit-level and symbol-level processing is shown according to embodiments of the present disclosure;

[0032] Figure 12 An example embodiment for CB segmentation is shown according to embodiments of the present disclosure;

[0033] Figure 13 An example embodiment for bit-level interleaver operation is shown according to embodiments of the present disclosure;

[0034] Figure 14 A flow diagram of an example method in which a UE receives a multi-layer data transmission according to embodiments of the present disclosure is shown;

[0035] Figure 15 A flow diagram of an example method in which a BS generates and transmits multi-layer data for a UE (labeled UE-k) according to embodiments of the present disclosure is shown. DETAILED DESCRIPTION

[0036] The following discussion of background art is not an admission of prior art. Figures 1 to 15 The principles of the present disclosure described in this patent document can be implemented in any of a variety of suitably arranged wireless communication systems.

[0037] List of acronyms

[0038] • 2D: two-dimensional

[0039] • MIMO: multiple-input multiple-output

[0040] • SU-MIMO: single-user MIMO

[0041] • MU-MIMO: multi-user MIMO

[0042] • 3GPP: Third Generation Partnership Project

[0043] • LTE: Long Term Evolution

[0044] • UE: user equipment

[0045] • eNB: evolved Node B or "eNB"

[0046] • BS: base station

[0047] • DL: downlink

[0048] • UL: Uplink

[0049] • CRS: Cell-specific Reference Signal(s)

[0050] • DMRS: Demodulation Reference Signal(s)

[0051] • SRS: Sounding Reference Signal(s)

[0052] • UE-RS: UE-specific Reference Signal(s)

[0053] • CSI-RS: Channel State Information Reference Signal

[0054] • SCID: Scrambling Identity

[0055] • MCS: Modulation and Coding Scheme

[0056] • RE: Resource Element

[0057] • CQI: Channel Quality Information

[0058] • PMI: Precoding Matrix Indicator

[0059] • RI: Rank Indicator

[0060] • MU-CQI: Multi-User CQI

[0061] • CSI: Channel State Information

[0062] • CSI-IM: CSI Interference Measurement

[0063] • CoMP: Coordinated Multi-Point

[0064] • DCI: Downlink Control Information

[0065] • UCI: Uplink Control Information

[0066] • PDSCH: Physical Downlink Shared Channel

[0067] • PDCCH: Physical Downlink Control Channel

[0068] • PUSCH: Physical Uplink Shared Channel

[0069] • PUCCH: Physical Uplink Control Channel

[0070] • PRB: Physical Resource Block

[0071] • RRC: Radio Resource Control

[0072] • AoA: Angle of Arrival

[0073] • AoD: Angle of Departure

[0074] The following documents and standards descriptions are hereby incorporated by reference into the present disclosure as if fully set forth herein: 3GPP Technical Specification (TS) 36.211 version 12.4.0, "E-UTRA, Physical channels and modulation" ("Reference 1"); 3GPP TS 36.212 version 12.3.0, "E-UTRA, Multiplexing and Channel coding" ("Reference 2"); 3GPP TS 36.213 version 12.4.0, "E-UTRA, Physical Layer Procedures" ("Reference 3"); 3GPP TS 36.321 version 12.4.0, "E-UTRA, Medium Access Control (MAC) Protocol Specification" ("Reference 4"); and 3GPP TS 36.331 version 12.4.0, "E-UTRA, Radio Resource Control (RRC) Protocol Specification" ("Reference 5").

[0075] Figure 1 An exemplary wireless network 100 according to various embodiments of the present disclosure is shown. Figure 1 The embodiment of the wireless network 100 shown in FIG. 1 is for illustration only. Other embodiments of the wireless network 100 could be used without departing from the scope of this disclosure.

[0076] Wireless network 100 includes base stations (BSs) 101, 102, and 103. BS 101 communicates with BSs 102 and 103. BS 101 also communicates with at least one Internet Protocol (IP) network 130, such as the Internet, a proprietary IP network, or other data network. Instead of “BS,” alternative terminology can be used, such as “eNB” (evolved Node B) or “gNB” (generic Node B). Depending on the network type, other well-known terminology can be used instead of “gNB” or “BS,” such as “base station” or “access point.” For convenience, the terms “gNB” and “BS” are used in this patent document to refer to network infrastructure components that provide wireless access to remote terminals. Also, depending on the network type, other well-known terminology can be used instead of “user equipment” or “UE,” such as “mobile station,” “subscriber station,” “remote terminal,” “wireless terminal,” or “user device.” For convenience, the terms “user equipment” and “UE” are used in this patent document to refer to remote wireless equipment that wirelessly accesses a gNB, whether the UE is a mobile device (such as a mobile telephone or smartphone) or is normally considered a fixed device (such as a desktop computer or vending machine).

[0077] GNB 102 provides wireless broadband access to network 130 for a first plurality of user equipment (UEs) within a coverage area 120 associated with gNB 102. The first plurality of UEs includes UE 111, which can be located in a small business (SB); UE 112, which can be located in an enterprise (E); UE 113, which can be located in a WiFi hotspot (HS); UE 114, which can be located in a first residence (R); UE 115, which can be located in a second residence (R); and UE 116, which can be a mobile device (M), such as a cell phone, a wireless laptop, a wireless PDA, or the like. GNB 103 provides wireless broadband access to network 130 for a second plurality of UEs within a coverage area 125 associated with gNB 103. The second plurality of UEs includes UE 115 and UE 116. In some embodiments, one or more of gNBs 101-103 can communicate with each other and with UEs 111-116 using 5G, LTE, LTE-A, WiMAX, or other advanced wireless communication techniques.

[0078] Dotted lines indicate approximate extents of the coverage areas 120 and 125 and the shapes are merely intended as an illustration to conceptually show the approximate relative positions of the coverage areas 120 and 125. It should be understood that the coverage areas associated with gNBs, such as the coverage areas 120 and 125, can have other shapes that do not appear to be circular or oval, including irregular shapes, depending upon configuration and variations of the radio environment associated with gNBs.

[0079] As described in more detail below, one or more of the gNBs 101, 102, and 103 transmit measurement reference signals to the UEs 111-116 and configure the UEs 111-116 for multi-stream transmission, as described in embodiments of the disclosure. In various embodiments, one or more of the UEs 111-116 receive one or two codewords depending on the number of layers of the transmission.

[0080] Although Figure 1 various changes can be made to Figure 1 wireless network 100. For example, wireless network 100 could include any number of gNBs and any number of UEs in any suitable arrangement. Also, gNB 101 could communicate directly with any number of UEs and provide those UEs access to network 130. Similarly, each gNB 102-103 could communicate directly with network 130 and provide UEs access to network 130. Further, gNBs 101, 102, and / or 103 could provide access to other or additional external networks, such as external telephone networks or other types of data networks.

[0081] Figure 2A and 2B An example wireless transmit and receive path is shown according to this disclosure. In the following description, the transmit path 200 can be described as implemented at a gNB (such as gNB 102), and the receive path 250 can be described as implemented at a UE (such as UE 116). However, it is to be understood that the receive path 250 can be implemented at a gNB, and the transmit path 200 can be implemented at a UE. In some embodiments, the receive path 250 is configured to receive one or two codewords depending on the number of layers of the transmission, as described in embodiments of the disclosure.

[0082] The transmit path 200 includes a channel coding and modulation block 205, a serial-to-parallel (S-to-P) block 210, a size N inverse fast Fourier transform (IFFT) block 215, a parallel-to-serial (P-to-S) block 220, a ‘add cyclic prefix’ block 225, and a frequency up-converter (UC) 230. The receive path 250 includes a frequency down-converter (DC) 255, a ‘remove cyclic prefix’ block 260, a serial-to-parallel (S-to-P) block 265, a size N fast Fourier transform (FFT) block 270, a parallel-to-serial (P-to-S) block 275, and a channel decoding and demodulation block 280.

[0083] In transmit path 200, channel coding and modulation block 205 receives a set of information bits, applies coding (e.g., convolutional, Turbo, or low-density parity-check (LDPC) coding), and modulates the input bits (e.g., using quadrature phase shift keying (QPSK) or quadrature amplitude modulation (QAM)) to generate a series of frequency-domain modulation symbols. S-to-P block 210 converts (e.g., demultiplexes) the serial modulation symbols into parallel data to generate N parallel symbol streams, where N is the IFFT / FFT size used in gNB 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. P-to-S block 220 converts (e.g., multiplexes) the parallel time-domain output symbols from IFFT block 215 of size N to generate a serial time-domain signal. 'Add cyclic prefix' 225 inserts a cyclic prefix into the time-domain signal. The UC 230 modulates (e.g., up-converts) the output of the 'Add Cyclic Prefix' block 225 to an RF frequency for transmission via a wireless channel. The signal can also be filtered at the baseband before conversion to the RF frequency.

[0084] The transmitted RF signal from gNB 102 reaches UE 116 after passing through the wireless channel, and the inverse operation at UE 116 is performed at gNB 102. DC 255 downconverts the received signal to the baseband frequency, and 'remove cyclic prefix' block 260 removes the cyclic prefix to generate a serial time-domain baseband signal. Serial-to-parallel 265 converts the time-domain baseband signal into a parallel time-domain signal. 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 signals into a modulated data symbol sequence. Channel decoding and demodulation block 280 demodulates and decodes the modulated symbols to recover the original input data stream.

[0085] As described in more detail below, transmit path 200 or receive path 250 can perform signaling for multi-stream transmission. Each of gNBs 101-103 can implement a transmit path 200 similar to that transmitted to UEs 111-116 in the downlink, and a receive path 250 similar to that received from UEs 111-116 in the uplink. Similarly, each of UEs 111-116 can implement a transmit path 200 for transmission to gNBs 101-103 in the uplink, and a receive path 250 for reception from gNBs 101-103 in the downlink.

[0086] Figure 2A and 2B Each component in the system can be implemented using only hardware or a combination of hardware and software / firmware. As a specific example, Figure 2A and 2BAt least some components can be implemented in software, while others can be implemented through configurable hardware or a hybrid of software and configurable hardware. For example, FFT block 270 and IFFT block 215 can be implemented as configurable software algorithms, where the value of size N can be modified depending on the implementation.

[0087] Furthermore, although the description uses FFT and IFFT, this is illustrative only and should not be construed as limiting the scope of this disclosure. Other types of transforms can be used, such as the Discrete Fourier Transform (DFT) and Inverse Discrete Fourier Transform (IDFT) functions. It should be understood that the value of variable N can be any integer used in the DFT and IDFT functions (e.g., 1, 2, 3, 4, etc.), and the value of variable N can also be any integer that is a power of 2 used in the FFT and IFFT functions (e.g., 1, 2, 4, 8, 16, etc.).

[0088] although Figure 2A and 2B An example of a wireless transmit and receive path is shown, but it is possible to modify it further. Figure 2A and 2B Make various changes. For example, Figure 2A and 2B The various components can be combined, further subdivided, or omitted, and additional components can be added as needed. Furthermore, Figure 2A and 2B This is intended to illustrate examples of the types of send and receive paths that can be used in a wireless network. Other suitable architectures can be used to support wireless communication in a wireless network.

[0089] Figure 3A Example UE 116 according to this disclosure is shown. Figure 3A The embodiment of UE 116 shown is for illustrative purposes only, and Figure 1 UEs 111-115 can have the same or similar configurations. However, UEs have a wide variety of configurations, and Figure 3A This disclosure is not intended to limit the scope to any particular implementation of the UE.

[0090] UE 116 includes an antenna 305, a radio frequency (RF) transceiver 310, a transmit (TX) processing circuitry 315, a microphone 320, and a receive (RX) processing circuitry 325. UE 116 also includes a speaker 330, a processor 340, an input / output (I / O) interface 345, an input 350, a display 355, and a memory 360. The memory 360 includes an operating system (OS) program 361 and one or more applications 362.

[0091] RF transceiver 310 receives signals from antenna 305. Figure 1The RF transceiver 310 receives, from the antenna 305, an incoming RF signal transmitted by a gNB of the wireless network 100. The RF transceiver 310 down-converts the incoming RF signal to generate an intermediate frequency (IF) or baseband signal. The IF or baseband signal is sent to the RX processing circuitry 325, which generates a processed baseband signal by filtering, decoding, and / or digitizing the baseband or IF signal. The RX processing circuitry 325 transmits the processed baseband signal to the speaker 330 (e.g., for voice data) or to the processor 340 for further processing (e.g., for web browsing data).

[0092] The TX processing circuitry 315 receives analog or digital voice data from the microphone 320 or other outgoing baseband data (such as web access data, e-mail, or interactive video game data) from the processor 340. The TX processing circuitry 315 encodes, multiplexes, and / or digitizes the outgoing baseband data to generate a processed baseband or IF signal. The RF transceiver 310 receives the outgoing processed baseband or IF signal from the TX processing circuitry 315 and up-converts the baseband or IF signal to an RF signal that is transmitted via the antenna 305.

[0093] The processor 340 can include one or more processors or other processing devices and execute the OS program 361 stored in the memory 360 in order to control the overall operation of the UE 116. For example, the processor 340 can control the reception of forward channel signals and the transmission of reverse channel signals by the RF transceiver 310, the RX processing circuitry 325, and the TX processing circuitry 315 in accordance with well-known principles. In some embodiments, the processor 340 includes at least one microprocessor or microcontroller.

[0094] The processor 340 is also capable of executing other processes and programs resident in the memory 360, such as operations for CQI measurement and reporting for systems described in embodiments of the present disclosure described in embodiments of the present disclosure. The processor 340 can move data into or out of the memory 360 as required by the processes executing on the processor 340. In some embodiments, the processor 340 is configured to execute the applications 362 based on the OS program 361 or in response to signals received from gNBs or an operator. The processor 340 is further coupled to the I / O interface 345, which provides the UE 116 with the ability to connect to other devices such as laptop computers and handheld computers. The I / O interface 345 is the communication path between these accessories and the processor 340.

[0095] The processor 340 is also coupled to the input 350 (e.g., keyboard, touchscreen, buttons, etc.) and the display 355. The operator of the UE 116 can use the input 350 to enter data into the UE 116. The display 355 can be a liquid crystal display or other display capable of rendering text and / or at least limited graphics, such as from web sites.

[0096] The memory 360 is coupled to the processor 340. A portion of the memory 360 may include random access memory (RAM), and another portion of the memory 360 may include flash memory or other read-only memory (ROM).

[0097] As described in more detail below, UE 116 can perform signaling and computation for multi-stream transmission. Although Figure 3A An example of UE 116 is shown, but it is possible to modify it. Figure 3A Make various changes. For example, Figure 3A The various components can be combined, further subdivided, or omitted, and additional components can be added as needed. As a specific example, 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). Moreover, although... Figure 3A The UE 116 is shown configured as a mobile phone or smartphone, but the UE can be configured to operate as other types of mobile or fixed devices.

[0098] Figure 3B An example gNB 102 according to this disclosure is shown. Figure 3B The embodiment of gNB 102 shown is for illustrative purposes only, and Figure 1 Other gNBs may have the same or similar configurations. However, gNBs have a wide variety of configurations, and Figure 3B The scope of this disclosure is not limited to any particular implementation of gNB. gNB 101 and gNB 103 may include the same or similar structures as gNB 102.

[0099] like Figure 3B As shown, gNB 102 includes multiple antennas 370a-370n, multiple RF transceivers 372a-372n, transmit (TX) processing circuitry 374, and receive (RX) processing circuitry 376. In some embodiments, one or more of the multiple antennas 370a-370n include a 2D antenna array. gNB 102 also includes a controller / processor 378, a memory 380, and a backhaul or network interface 382.

[0100] The RF transceivers 372a-372n receive the incoming RF signals, such as signals transmitted by a UE or other gNBs, from the antennas 370a-370n. The RF transceivers 372a-372n down-convert the incoming RF signals to generate IF or baseband signals. The IF or baseband signals are sent to the RX processing circuitry 376, which generates processed baseband signals by filtering, decoding, and / or digitizing the baseband or IF signals. The RX processing circuitry 376 transmits the processed baseband signals to the controller / processor 378 for further processing.

[0101] The TX processing circuitry 374 receives analog or digital data, such as voice data, web data, e-mail, or interactive video game data from the controller / processor 378. The TX processing circuitry 374 encodes, multiplexes, and / or digitizes the outgoing baseband data to generate processed baseband or IF signals. The RF transceivers 372a-372n receive the outgoing processed baseband or IF signals from the TX processing circuitry 374 and up-convert the baseband or IF signals to RF signals that are transmitted via the antennas 370a-370n.

[0102] The controller / processor 378 can include one or more processors or other processing devices to manage the overall operation of the gNB 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 372a-372n, the RX processing circuitry 376, and the TX processing circuitry 374 in accordance with well-known principles. The controller / processor 378 can support additional functions as well, such as more advanced wireless communication functions. In some embodiments, the controller / processor 378 includes at least one microprocessor or microcontroller.

[0103] The controller / processor 378 is also capable of executing programs and other processes resident in the memory 380, such as an OS. The controller / processor 378 is also capable of supporting channel quality measurement and reporting for systems with 2D antenna arrays, as described in the embodiments of the present disclosure. In some embodiments, the controller / processor 378 supports communication between entities such as network RTCs. The controller / processor 378 can move data into or out of memory 380 as needed by executing processes.

[0104] The controller / processor 378 is also coupled to a backhaul or network interface 382. The backhaul or network interface 382 allows the gNB 102 to communicate with other devices or systems via a backhaul connection or over a network. The backhaul or network interface 382 can support communication via any suitable wired or wireless connection(s). For example, when the gNB 102 is implemented as part of a cellular communication system (such as a system supporting 5G or new radio access technologies or NR, LTE, or LTE-A), the backhaul or network interface 382 can allow the gNB 102 to communicate with other gNBs via a wired or wireless backhaul connection. When the gNB 102 is implemented as an access point, the backhaul or network interface 382 can allow the gNB 102 to communicate with a larger network (such as the Internet) via a wired or wireless local area network or via a wired or wireless connection. The backhaul or network interface 382 includes any suitable architecture supporting communication via a wired or wireless connection, such as an Ethernet or RF transceiver.

[0105] Memory 380 is coupled to controller / processor 378. A portion of memory 380 may include RAM, and another portion of memory 380 may include flash memory or other ROM. In some embodiments, multiple instructions, such as a BIS algorithm, are stored in memory. The multiple instructions are configured to cause controller / processor 378 to perform the BIS process and decode the received signal after subtracting at least one interference signal determined by the BIS algorithm.

[0106] As described in more detail below, the transmit and receive paths of the gNB 102 (implemented using RF transceivers 372a-372n, TX processing circuitry 374, and / or RX processing circuitry 376) receive one or two codewords depending on the number of transport layers.

[0107] although Figure 3B An example of gNB 102 is shown, but it is possible to compare it with other models. Figure 3B Various changes can be made. For example, gNB102 can include any number of Figure 3A Each component shown. As a specific example, an access point may include multiple backhaul or network interfaces 382, ​​and a controller / processor 378 may support routing functionality to route data between different network addresses. As another specific example, although shown as a single instance including TX processing circuitry 374 and a single instance including RX processing circuitry 376, gNB 102 may include multiple instances of each (such as one per RF transceiver).

[0108] Rel. 13 LTE supports up to 16 CSI-RS antenna ports, which enables the gNB to be equipped with a large number of antenna elements (e.g. 64 or 128). In this case, multiple antenna elements are mapped onto one CSI-RS port. Furthermore, up to 32 CSI-RS ports will be supported in Rel. 14 LTE. For next generation cellular systems such as 5G, the maximum number of CSI-RS ports is expected to more or less remain the same.

[0109] For mmWave bands, although the number of antenna elements can be larger for a given form factor, as Figure 4 embodiment 400, the number of CSI-RS ports, which can correspond to the number of digitally precoded ports, tends to be limited due to hardware constraints (e.g. feasibility of installing a large number of ADCs / DACs at mmWave frequencies). In this case, one CSI-RS port is mapped onto a large number of antenna elements, which can be controlled by a set of analog phase shifters 401. One CSI-RS port can then correspond to one subarray, which produces a narrow analog beam through analog beamforming 405. The analog beam can be configured to sweep over a wider range of angles 420 by changing the phase shifter set across symbols or subframes or slots (where a subframe or slot comprises a set of symbols). The number of subarrays (equal to the number of RF chains) is the same as the number of CSI-RS ports N CSI-PORT . Digital beamforming unit 410 performs a linear combination across the N CSI-PORT analog beams to further increase the precoding gain. While the analog beams are wideband (hence not frequency-selective), the digital precoding can vary across frequency subbands or resource blocks.

[0110] In LTE, up to two codewords are used for spatially multiplexed DL and UL data transmission (on DL data channels such as PDSCH or PDCH and UL data channels such as PUSCH or PUCCH, respectively), depending on the number of transmission layers, as shown in process 500 in Figure 5 (see Table 5.3.2A-1-2 and 6.3.3.2-1 of reference 1 for UL and DL, respectively). The output of the modulation mapper 501 (which maps the bit stream(s) generated by channel coding, rate matching and scrambling) is taken, and layer mapping 510 maps the 1 or 2 codewords to L layers before precoding 502. For L = 1, one codeword is mapped to one layer (511). For L > 1, each of the two codewords is mapped to at least one layer (512), with the L layers being almost evenly split across the two codewords. In addition, one codeword can also be mapped to > 1 layer, especially when only one of the two codewords is to be retransmitted.

[0111] While beneficial to facilitate modulation and coding scheme (MCS) adaptation for each codeword (CW) and MMSE-SIC (MMSE with successive interference cancellation) receivers, it incurs some significant overhead over single CW mapping. DL overhead comes from the additional DCI payload by 2 fixed MCS fields and 2 fixed NDI-RV (DL HARQ related) fields. UL overhead comes from the need for two CQIs (all 4 bits for wideband CQI + delta 3 bits, and 2x overhead for subband CQI) for rank > 1 and two DL HARQ-ACKs for rank > 1. In addition to this, there is also the complexity of having to accommodate more than one layer mapping scheme in case of retransmission.

[0112] Furthermore, when distributed MIMO such as non-coherent joint transmission (NC-JT) is incorporated into the design requirements of 5G NR, the number of codewords (CWs) for DL and UL transmission per UE can increase with the number of TRPs.

[0113] Accordingly, in view of the above new challenges for 5G NR systems, there is a need for improved codeword-to-layer mapping (or simply "layer mapping") with a single CW for DL and UL per UE - along with its signaling support.

[0114] In the case where 2-CW transmission (per PDSCH / PUSCH allocation per UE) is used for higher rank transmission, it is desirable to introduce additional components in the CW-to-layer mapping that facilitate the control signaling overhead of 1-CW transmission: 1 MCS and 1 HARQ related DCI field, 1 CQI for L layers. This is relevant, for example, when 1 < L < 4, 1 CW is mapped to L layers, and when 5 < L < 8, 2 CWs are mapped to L layers. In this example, additional CW-to-layer mapping components are introduced when 5 < L < 8. Alternatively, in a second example, when 1 < L < 2, 1 CW is mapped to L layers, and when 3 < L < 8, 2 CWs are mapped to L layers. In this example, additional CW-to-layer mapping components are introduced when 3 < L < 8.

[0115] Accordingly, there is also a need to introduce additional components in the CW-to-layer mapping that facilitate the control signaling overhead of 1-CW transmission.

[0116] The present disclosure includes the following components for enabling reception of one or two codewords depending on the number of transmission layers. A first component includes a transmission scheme (which includes multi-TRP support, code block segmentation, and layer mapping). A second component relates to signaling support.

[0117] Each of these components, including components described later, can be used alone or in combination with at least one of the other components. Also, each of these components includes a plurality of sub-components. Each sub-component can be used alone or in combination with at least one other sub-component.

[0118] The first component (i.e., transmission scheme) includes features to support multi-TRP (transmit-receive point) transmission / reception. For DL, the number of TRPs involved in DL transmission on a DL data channel (such as PDSCH or PDCH) can not be indicated to the UE (thus transparent). Thus, an increase in the number of CWs received by the UE for multi-TRP scenarios (e.g., when non-coherent JT is used) can be supported via a configurable number of CWs received by the UE.

[0119] In a first embodiment, the number of CWs received by the UE can be configured. This can be signaled via higher layer (RRC) signaling, MAC control element (CE), or L1 DL control signaling (carried by a single DL-related DCI). Regardless of how the configuration is signaled, multi-TRP transmission is allocated using a single DCI (even if non-coherent JT is used). However, this first embodiment requires the UE to support reception with different number of CWs for a given number of layers.

[0120] Alternatively, the number of received CWs can be defined or specified to be less coupled with multi-TRP setup. In a second embodiment, a single CW is mapped to one or more layers (regardless of the number of layers) of each DL data channel (such as PDSCH or PDCH) reception / allocation per UE. Thus, M-TRP transmission is allocated using M separate DCIs (e.g., using non-coherent JT). Additionally, the UE capability can be defined in terms of the number of DL data channel (e.g., PDSCH or PDCH) reception / allocation per slot or subframe.

[0121] For UL, a single CW is mapped to one or more layers (regardless of the number of layers) of each UL data channel grant (such as PUSCH or PUCH) reception / allocation per UE. Additionally, the UE capability can be defined in terms of the number of UL data channel grant (such as PUSCH or PUCH) reception / allocation per slot or subframe.

[0122] The first component (i.e., transmission scheme) also includes code block (CB) segmentation. A CW is derived from a transport block (TB). Depending on its size, a TB can be segmented into one or more code blocks (CBs) in order to limit the channel decoding latency at the UE. For example, in LTE, one CB can be decoded and facilitate early detection of TB decoding failure.

[0123] Figure 6 The CB segmentation process 600 is shown, where a TB 601 is divided into multiple CBs (with the special case of being divided into one CB when the TB size is small) 602. Given the number of layers L, the selected MCS, the resource allocation, and possibly some other transmission parameters, the CB segmentation 610 can include at least one of the following functions: segmentation of the TB into one or more CBs, padding (to ensure a certain CB size before channel coding), introduction of CRC bits per CB (referred to as CB CRC). In addition, TB CRC bits can be added at the end 602 (as in LTE). However, to reduce overhead and functional redundancy, the TB CRC is not needed and hence not added.

[0124] In an alternative embodiment, the CB CRC is not introduced (i.e., CRC bits are not added to the CB). In this alternative embodiment, the CB segmentation can include at least one of the following functions: padding (to ensure a certain CB size before channel coding) - but without introducing CRC bits per CB (referred to as CB CRC). This can be done, for example, when using LDPC (Low Density Parity Check) coding, as the error detection functionality is inherent in LDPC (hence no CRC is needed). As a result, the TB CRC is also not needed.

[0125] The CW is formed after processing the output of the CB segmentation by channel coding (including rate matching).

[0126] To support single CW transmission, the following embodiments for CB segmentation are given. In one embodiment, the CB segmentation can be defined such that for L-layer transmission (DL or UL), the TB (and hence the CW) includes an integer number of L code blocks (CBs). In addition, the following additional rule can be added: when the number of CBs in the received (DL) or transmitted (UL) TB / CW is less than the maximum number of layers supported by the UE, the number of layers assigned to this UE layer is set equal to the number of CBs in the received (DL) or transmitted (UL) TB / CW.

[0127] The first component (i.e., the transmission scheme) also includes the CW-to-layer mapping (or simply layer mapping). The support of single CW UL transmission and DL reception per UE can be done via one of the following embodiments of the layer mapping.

[0128] In the following embodiments and sub-embodiments, either of the following two different RE mapping schemes applies: frequency-first and time-first.

[0129] The modulated symbol stream {d(i)} (indexed by i) is formed by concatenating the modulated symbols from the CBs associated with a single CW / TB. This symbol stream {d(i)} is used as input to the layer mapping.

[0130] For frequency-first mapping, the modulated symbol stream is first mapped across frequency subcarriers (REs) within a set of allocated PRBs, and then across OFDM symbols within a scheduling time unit (slot or subframe). To illustrate, given a modulated symbol stream {d(i)} mapped to indices {(k, l)} (where k and l denote frequency / subcarrier and time / OFDM symbol indices, respectively), when index i increases, frequency-first mapping maps d(i) by first increasing index k from 0 to k MAX - 1 (for fixed l), and then increasing index l. That is, k = mod(i, k MAX ) and where k MAX is the number of frequency subcarriers (REs) in an allocated PRB.

[0131] For time-first mapping, the modulated symbol stream is first mapped across OFDM symbols within a scheduling time unit (slot or subframe), and then across frequency subcarriers (REs) within a set of allocated PRBs. To illustrate, given a modulated symbol stream {d(i)} mapped to indices {(k, l)} (where k and l denote frequency / subcarrier and time / OFDM symbol indices, respectively), when index i increases, time-first mapping maps d(i) by first increasing index l from 0 to l MAX - 1 (for fixed k), and then increasing index k. That is, and l = mod(i, l MAX ), where l MAX is the number of OFDM symbols in a scheduling time unit (slot or subframe).

[0132] Frequency-first mapping is used for illustrative purposes in the following embodiments and sub-embodiments for a given (spatial) layer. The extension to time-first mapping is straightforward to those familiar with the art.

[0133] In one embodiment, one CW is mapped to L layers on a per-symbol basis. Here, a symbol denotes a QPSK or M-QAM modulated symbol (i.e., the output of a modulation mapper) resulting from mapping a set of coded bits to a QPSK or M-QAM constellation. This embodiment is illustrated in Figure 7A At least three mapping schemes 700 can be used: vertical (710), diagonal (720), and horizontal (730). The symbol-level mapping schemes perform mapping from a modulated symbol stream (from one CW) to L layers on the allocated frequency and time resources.

[0134] A modulated symbol stream {d(i)} (indexed by i) is formed by concatenating in series the modulated symbols from the CBs associated with a single CW / TB. This symbol stream {d(i)} is used as input for layer mapping.

[0135] For vertical mapping, the symbol stream is first mapped across L layers, then across frequency subcarriers (REs) within a set of allocated PRBs, then across OFDM symbols within a scheduled time unit (slot or subframe). The mapping is described using the same notation as follows. x (l) (i) and d(i) are defined as the number of symbols per layer, the number of symbols in a CW, the symbol stream of layer / , and the symbol stream of a CW, respectively, the CW-to-layer mapping can be described as follows.

[0136] Here, CB segmentation and / or rate matching ensures that is divisible by L.

[0137]

[0138]

[0139] For horizontal mapping, the symbol stream is first mapped across frequency subcarriers (REs) within a set of allocated PRBs, then across OFDM symbols within a scheduled time unit (slot or subframe), then across L layers. Using the same notation, the CW-to-layer mapping can be described as follows. Here, CB segmentation and / or rate matching ensures that is divisible by L.

[0140]

[0141]

[0142] For diagonal mapping, the symbol stream can be first mapped across layers and frequency subcarriers (REs) within a set of allocated PRBs together, then across OFDM symbols within a scheduled time unit (slot or subframe). Alternatively, the symbol stream can be mapped across layers, frequency subcarriers (REs) within a set of allocated PRBs, and OFDM symbols within a scheduled time unit (slot or subframe) together. For example, using the same notation, the CW-to-layer mapping can be described as follows (for the second alternative). Here, CB segmentation and / or rate matching ensures that is divisible by L.

[0143]

[0144]

[0145] In another embodiment, one CW is mapped to L layers on a per-symbol or per-CB basis depending on the number of CBs in the received (DL) or transmitted (UL) TB / CW. By Figure 7BThe mapping scheme 750 illustrates an example. If the number of CBs in the received (DL) or transmitted (UL) TB / CW is less than the integer value K, then symbol-level vertical mapping 760 is used (see Equation 1). Otherwise, if the number of CBs in the received (DL) or transmitted (UL) TB / CW is greater than or equal to the integer value K, then CB-level vertical mapping 770 is used. The use of CB-level vertical mapping can facilitate the UE to use a CB-level MMSE-SIC receiver.

[0146] CB-level vertical mapping can be described as follows.

[0147] The symbol stream associated with the first CB (CB 0) is mapped to the first layer (Layer 0) and the first mapped frequency subcarriers (REs) within the set of allocated PRBs, and then, if necessary, to the OFDM symbols across the scheduled time unit (slot or subframe). The extent to which the first CB is mapped to the OFDM symbols within the set of allocated PRBs and the scheduled time unit depends on the number of CBs in the received (DL) or transmitted (UL) TB / CW.

[0148] The symbol stream associated with the second CB (CB 1) is then mapped to the second layer (Layer 1) and the first mapped frequency subcarriers (REs) within the set of allocated PRBs, and then, if necessary, to the OFDM symbols across the scheduled time unit (slot or subframe). The extent to which the second CB is mapped to the OFDM symbols within the set of allocated PRBs and the scheduled time unit depends on the number of CBs in the received (DL) or transmitted (UL) TB / CW, and is the same as the first CB.

[0149] This process is repeated until the symbol stream associated with the Lth CB (CB L-1) is mapped to the Lth layer (Layer L-1) and the first mapped frequency subcarriers (REs) within the set of allocated PRBs, and then, if necessary, to the OFDM symbols across the scheduled time unit (slot or subframe). The extent to which the Lth CB is mapped to the OFDM symbols within the set of allocated PRBs and the scheduled time unit depends on the number of CBs in the received (DL) or transmitted (UL) TB / CW, and is the same as the first CB.

[0150] If the number of CBs in the received (DL) or transmitted (UL) TB / CW is greater than L (an integer multiple of L), then the mapping process is repeated with the symbol stream associated with the (n+1)th CB (CB n+1) mapped to the (mod(n, L)+1)th layer (Layer mod(n, L)). When mapping CBs, L layers are occupied as well as the OFDM symbols within the entire set of allocated PRBs and the scheduled time unit (slot or subframe).

[0151] In Figure 8CB level vertical mapping 800 is further illustrated. The number of CBs in a received (DL) or transmitted (UL) TB / CW is an integer multiple of L (μL, where μ≥1). When μ=1, each of the L CBs is mapped to a layer (in this example, CB l is mapped to layer l). Each of the L CBs is mapped to across frequency subcarriers (REs) within an entire set of allocated PRBs and OFDM symbols within a scheduled time unit (slot or subframe). Thus, the mapping is first performed over frequency (subcarriers or resource elements, REs) within one OFDM symbol and then across OFDM symbols within a scheduled time unit (slot or subframe). This is illustrated in embodiment 810. When μ>1, CBs {l+mL, m=0,1,...,μ-1} are mapped to layer l. Assuming the total number of REs within an entire set of allocated PRBs across OFDM symbols within a scheduled time unit (slot or subframe) is k MAX l MAX , then the first L CBs are mapped to across the first L REs (in frequency and time), the second L CBs are mapped to across the second L REs (in frequency and time),..., and the last (μth) L CBs are mapped to across the last (μth) L REs (in frequency and time). An example μ=2 is illustrated in embodiment 820.

[0152] More precisely, given a stream of modulation symbols {d(i)} formed by concatenating modulation symbols from μL CBs (associated with a single CW / TB), the total number of modulation symbols is equal to BμL=k MAX l MAX L, where B is the number of modulation symbols per CB and k MAX l MAX is the total number of REs within an entire set of allocated PRBs across OFDM symbols within a scheduled time unit (slot or subframe). Thus, All CBs have the same size and use the same MCS. That is, {CB n, CB n+1,..., CB n+L-1} share the same CB size B for different n values. Here, the modulation symbols d(i) are mapped to a modulation symbol stream associated with layer l as follows:

[0153]

[0154]

[0155] In an alternative sub-embodiment of the previous paragraph, {CB n, CB n+1,..., CB n+L-1} share the same CB size B only for a given n valuen However, the size of CB can be different for different values ​​of n.

[0156] In this example, the value of K is fixed at L (number of layers). In another example of this embodiment, the value of K is fixed at an integer multiple of L (μL), where μ≥1 can be fixed or configurable.

[0157] In this example, the CB-level vertical mapping is replaced by the CB-level horizontal mapping. Figure 8 Examples of CB-level horizontal mapping 830 (with components 840 and 850) are shown for L and 2L CBs, respectively. In another example of this embodiment, the CB-level vertical mapping is replaced by the CB-level diagonal mapping. Figure 8 Examples of CB-level diagonal mappings 860 (with components 870 and 880) are shown for L and 2L CBs, respectively. Note that when the number of CBs in the received (DL) or transmitted (UL) TB / CW is L (μ = 1), the vertical, horizontal, and diagonal CB-level mappings can be the same.

[0158] In another embodiment, regardless of the number of CBs in the received (DL) or transmitted (UL) TB / CW, a CW is mapped to L layers on a per CB basis (as described above for CB-level vertical mapping). An additional constraint may be used: when the number of CBs in the received (DL) or transmitted (UL) TB / CW is less than the maximum number of layers supported by the UE, the number of layers allocated to the UE is set to be equal to the number of CBs in the received (DL) or transmitted (UL) TB / CW.

[0159] In another embodiment (“Configurable Layer Mapping”), the maximum number N of CWs that the UE can receive in a single PDSCH or PUSCH allocation is [not specified]. CW,MAX This can be configured via higher-layer (RRC) signaling, MAC control elements (MAC CE), or L1 DL control signaling (DL or UL-related DCI). In this case, the number of CWs received by the UE for a given number of layers L is N. CW =min(L,N) CW,MAX In one example of this embodiment, N CW,MAX It can be configured to 1 or 2. When N CW,MAX When = 1, the layer mapping utilizes a CW mapped to L layers. Above (in Figure 7A , 7B Any of the embodiments described in (or 8) is applicable (e.g., symbol-level vertical mapping or CB-level vertical mapping). When N CW,MAX When = 2, according to Figure 7A The layer mapping described in embodiment 700 utilizes N mapped to L layers.CW = min(L, 2) CWs. Alternatively, when N CW,MAX = 2 and the total number of layers received by the UE ≥ 2, CW0 is mapped to L0 ≥ 1 layers, CW1 is mapped to L1 layers, resulting in a total number of L = L0 + L1 layers received by the UE. In this case, each CW can utilize any of the above (in Figure 7A , 7B or 8, symbol-level or CB-level mapping, e.g., symbol-level vertical mapping or CB-level vertical mapping) single CW layer mapping embodiments. Note that for L ≥ 2, N CW,MAX is equal to N CW .

[0160] In a variant of the above “configurable layer mapping” embodiments, the configurability of N CW,MAX may depend on the maximum rank (or transmission layer) number L MAX that the UE is configured to receive (DL) or transmit (UL). In one example, when L MAX ≤ 2, N CW,MAX = N CW = 1 (single CW layer mapping, such as symbol-level vertical mapping or CB-level vertical mapping). Otherwise (L MAX > 2), N CW,MAX may be configured according to the description in the above paragraph. For example, in this case, N CW,MAX (equal to N CW ) can be configured to be 1 or 2. In another example, when L MAX ≤ 4, N CW,MAX = NCW= 1 (single CW layer mapping, such as symbol-level vertical mapping or CB-level vertical mapping). Additionally, when (L MAX > 4), N CW,MAX may be configured according to the description in the above paragraph. For example, in this case, N CW,MAX (equal to N CW ) can be configured to be 1 or 2. In another example, N CW,MAX (equal to N CW ) can be configured to be 1, 2, 3, or 4 (or alternatively, 1, 2, or 4). In another example, when L MAX ≤ 2, N CW,MAX = N CW = 1 (single CW layer mapping, such as symbol-level vertical mapping or CB-level vertical mapping). Otherwise, when 2 < L MAX ≤ 4, N CW,MAX (equal to N CW ) can be configured to be 1 or 2. Otherwise, when 4 < L MAX ≤ 6, N CW,MAX may be configured to be 1, 2, or 3. Otherwise, when 6 < LMAX ≤ 8, N CW,MAX may be configured to be 1, 2, 3, or 4 (or alternatively, 1, 2, or 4).

[0161] In another variant of the above-described “configurable layer mapping” embodiment, the number of CWs N CW may be set as a function of the number of transmission layers (ranks). In one example, when the number of layers L is 1, 2, 3, or 4, N CW may be set to 1 (single CW layer mapping, such as symbol-level vertical mapping or CB-level vertical mapping). Otherwise, when L is 5, 6, 7, or 8, N CW may be set to 2 (two CWs, where CW0 is mapped to layers, and CW1 is mapped to layers, as shown in the embodiment illustrated in FIG. 2B. In this case, when L is 1, 2, 3, or 4, the layer mapping for each of the two CWs is the same as the layer mapping for one CW. Figure 5

[0162] For the above-described variant embodiments, if symbol-level vertical mapping is used, the layer mapping scheme can be described as follows. When the number of layers L is 1, 2, 3, or 4,

[0163]

[0164]

[0165] When the number of layers L is 5, 6, 7, or 8, d (n) (i) is represented as a symbol stream associated with CW-n (n = 0, 1),

[0166]

[0167]

[0168]

[0169] In yet another variant of the above-described “configurable layer mapping” embodiment, the number of CWs N CW is set as a function of the number of transmission layers (ranks) as follows. When the number of layers L is 1 or 2, N CW may be set to 1 (single CW layer mapping, such as symbol-level vertical mapping or CB-level vertical mapping). Otherwise, when L is 3 or 4, the number of CWs N CW may be configured to be 1 or 2. Otherwise, when L is 5, 6, 7, or 8, the number of CWs N CW may be set to 2.

[0170] ​When the number of CWs is 1, one example layer mapping scheme based on symbol level vertical mapping can be described in equation (1) for a given L value. When the number of CWs is 2, one example layer mapping scheme based on symbol level vertical mapping can be described in equation (6) for a given L value.

[0171] The following embodiments of component 1 relate to enhancements when the number of transmission layers L exceeds a certain value and the number of CWs of a transmission is 2. For illustrative purposes, frequency first mapping is used in the following embodiments and sub-embodiments for a given (spatial) layer. Extensions to time first mapping are straightforward to those familiar with the art.

[0172] One embodiment (Embodiment I) is shown in Figure 9A Figure 9A CW to layer mapping 900 in uses 1 CW or 2 CWs, depending on the number of transmission layers or rank L. When 1≤L≤x1, 1-CW mapping (910) is used. When L>x2, 2-CW mapping (920+925) with an additional component called “CW cycling” (925) is used. The values of x1 and x2 can be equal or different. For example, for x1=x2=x, x can be 2 or 4. Alternatively, if x1>x2 (e.g., x1=4, x2=2), the mapping can be configured between 1-CW mapping in 910 and 2-CW mapping in 920+925 when L=4.

[0173] Each of the two mapping blocks (910 or 920) maps one CW onto at least one layer. In Figure 9A the first CW (CW0) is mapped onto layers, while the second CW (CW1) is mapped onto layers. At least three mapping schemes can be used: vertical, diagonal, and horizontal. A symbol level mapping scheme performs mapping from a stream of modulation symbols (from one CW) to at least one layer across the allocated frequency and time resources. For illustrative purposes, vertical mapping is used in the following example embodiments. Extensions to diagonal or horizontal mapping are straightforward to those familiar with the art.

[0174]

[0174] For symbol level vertical mapping, a symbol stream is first mapped across L layers, then across frequency subcarriers (REs) within a set of allocated PRBs, and then across OFDM symbols within a scheduled time unit (slot or subframe). The x (l) (i) and d(i) are denoted as the number of symbols per layer, the number of symbols in a CW, the symbol stream of layer l, and the symbol stream of a CW, respectively, the CW to layer mapping can be described as follows. Here, CB segmentation and / or rate matching ensures divisible by L. When the number of layers L is 1 < L < x1

[0175]

[0176]

[0177] Otherwise, when L > x2, d (n) (i) is represented as a symbol stream associated with CWn (n = 0, 1)

[0178]

[0179]

[0180]

[0181] or equivalently,

[0182]

[0183]

[0184]

[0185] CW cycling 925 is used to facilitate control signaling overhead for 1-CW transmission of 2-CW transmission. For example, this can be done by ensuring that each of the 2 CWs (or each code block / CB in each of the 2 CWs) is transmitted across L layers. In one example, CW cycling can be performed by intermittently switching between CW0 and CW1 with two sets of delta symbols. This can be described as follows.

[0186] Let the input and output of the CW cycling be represented as and The CW cycling operation can be described as follows:

[0187]

[0188]

[0189]

[0190] To ensure that each CB in a CW is mapped more or less uniformly across L layers and that these layers are symbol-level, Δ can be chosen as in equation (10). The values of Δ for different values of L are given in Table 1. Note that each value of Δ in Table 1 is only applicable when 2-CW transmission is used for the corresponding value of L. For example, when x1 = x2 = 4 in equations (7)-(8), CW cycling is only used for L > 4. Thus, the relevant values of Δ are only those corresponding to L = 5, 6, 7, and 8.

[0191]

[0192] Table 1

[0193] L Delta 2 1 3 2 4 2 5 6 6 3 7 12 8 4

[0194] It is possible Figure 9B The above example of CW cycle 925 is shown in mapping 950. As shown, groups / blocks of Δ symbols from CW0 are swapped with groups / blocks of Δ symbols from CW1 every other group / block. To further illustrate this operation, using the symbol-level vertical mapping described in formula (8), and with the Δ values ​​given in Table 1, consider the following two cases.

[0195] First, when mod(L,2)=0, the symbol sequences associated with each of the two CWs are mapped across L layers in the following manner:

[0196]

[0197]

[0198] Secondly, when mod(L,2)=1, the symbol sequences associated with each of the two CWs are mapped across L layers in the following manner. For illustrative purposes, L=5 (therefore Δ=6).

[0199]

[0200]

[0201] In a variant of this embodiment, the CW loop function can be enabled or disabled (and is therefore configurable for the UE). For example, CW loop can be enabled for the UE (via gNB or NW) when performing SU-MIMO transmissions, and disabled when the UE receives transmissions from multiple TRPs. This configuration can be signaled via higher-layer (e.g., RRC) signaling, MAC CE, or L1 DL control signaling (UL or DL-related DCI). This applies when the number of transport layers L > x2.

[0202] exist Figure 10 Another embodiment (Example II) is shown in the figure. Figure 10The CW-to-layer mapping 1000 in FIG. 10 uses 1 CW or 2 CWs, depending on the number of transmission layers or rank L. When 1 < L < xi, a 1-CW mapping is used (1010). When L > x2, a 2-CW mapping (1020 + 1025) with an additional component called “CW cycling” is used (1025). The values of xi and x2 can be equal or different. For example, for xi = x2 = x, x can be 2 or 4. Alternatively, if xi > x2 (e.g., xi = 4, x2 = 2), the mapping can be configured between the 1-CW mapping in 1010 and the 2-CW mapping in 1020 + 1025 when L = 4.

[0203] Each of the two mapping blocks (1010 or 1020) maps one CW onto at least one layer in a similar manner as in Embodiment I (blocks 910 and 920). Therefore, the above description of 810 and 820 applies to 1010 and 1020, including equations (7) and (8). The layer cycling 1025, just like the CW cycling, is used to facilitate the control signaling overhead for 1-CW transmission for 2-CW transmission. For example, this can be done by ensuring that each of the 2 CWs (or each code block / CB in each of the 2 CWs) is transmitted across L layers. In one example, the layer cycling across L layers can be performed by cyclically arranging the L layers in a symbol level. This operation can guarantee that the symbols within each CW are more or less evenly distributed across the L layers. This symbol level arrangement can be described as follows:

[0204]

[0205] π(l + i) = mod(l + i, L), l = 0, 1,..., L - 1 (Equation 13)

[0206] Alternatively, this example of layer cycling can be described with precoding as follows:

[0207]

[0208] π(l + i) = mod(l + i, L), l = 0, 1,..., L - 1 (Equation 14)

[0209] Here, e k is a vector of length L with its kth element being 1 and 0 elsewhere (k = 0, 1,..., L - 1).

[0210] To further illustrate this operation, using the symbol level vertical mapping described in Equation (8), the above example for layer cycling can be illustrated by the following mapping operation (across layer and symbol index i):

[0211]

[0212] In a variant of this embodiment, the layer cycling function can be turned on or off (hence configurable for the UE). For example, the layer cycling can be turned on for the UE (by the gNB or NW) when SU-MIMO transmission is performed, while the layer cycling can be turned off when the UE receives transmission(s) from multiple TRPs. This configuration can be signaled via higher layer (e.g., RRC) signaling, MAC CE, or L1 DL control signaling (UL or DL related DCI). This is applicable when the number of transmission layers L > x2.

[0213] The two embodiments above can also be extended for the scenario where the number of CWs is greater than 2. These extensions are straightforward to those familiar in the art.

[0214] In each of the two embodiments, the gNB / NW can configure different values (x1, x2) for the UE for DL and UL. The values of x1 and / or x2 can also be configurable for the UE.

[0215] In another embodiment (Embodiment III), when the UE is configured to receive 2 CWs and the total number of layers across 2 CWs (=L) is 5, 6, 7, or 8, instead of the fixed correspondence (described previously), a flexible correspondence between 2 CWs and L layers can be used.

[0216] In a sub-embodiment (III.1), a fully flexible correspondence adds the following features on top of the fixed correspondence. The first feature is that for a given number of layers L (>4), each of the 2 CWs can correspond to a different number of layers. Without any constraint, Table 2 summarizes the possible combinations of (L0, L1) where L n denotes the number of layers associated with CW-n. The bold combinations are the combinations for the LTE fixed correspondence. Hence, for a given L value, there are (L-1) possibilities. The second feature is that for a given number of layers L n associated with CW-n can also vary. Hence, for a given L and L0, there are possibilities.

[0217] Table 2 All possible number of layers per CW in 2 CWs

[0218]

[0219] Hence, for a given L value, the total number of possible correspondences is This leads to 205, 1236, 8659 and 69280 possibilities for L = 5, 6, 7 and 8, respectively. Since this correspondence needs to be signaled in the DCI (DL) and / or CSI report (UL), up to 17 bits of signaling field are needed.

[0220] In sub-embodiment (III.2), the fully flexible correspondence in III.1 is further restricted in the following way. Only combinations for L0≤ L1 are included. This is outlined in the third column of Table 2.

[0221] In sub-embodiment (III.3), the fully flexible correspondence in III.1 is further restricted in the following way. First, any functionality that features handling of cross-layer ordering (as in schemes 2 and 6) can be removed, since it is expected that such functionality, if beneficial at all, is handled by precoding (i.e., ordering / arranging is a special case of phase rotation). This is a reasonable assumption as long as the codebook is designed to have sufficiently high spatial resolution. Second, to ensure that no new layer mapping schemes (mapping one CW to > 1 layers) are introduced, the need for L n >4 possibilities should be removed. If the above two criteria are applied to the schemes that design flexible correspondence, the remaining possible combinations of (L0, L1) are outlined in the fourth column of Table 2. This leaves (9-L) combinations for a given L value. In addition, feature 2 disappears, leading to a total of (9-L) possibilities for a given L value (requiring at most 2 bits). This variable correspondence scheme can be described as follows. The first L0layers correspond to the first CW (CW0), where L0∈ {L-4,..., 4}, while the remaining (L-L0) layers correspond to the second CW (CW1).

[0222] In sub-embodiment (III.4), the fully flexible correspondence in III.3 is further restricted in the following way. Only combinations for L0≤ L1 are included. This is outlined in the fifth column of Table 2.

[0223] In other sub-embodiments of II, any subset of the combinations in Table 2 can be used.

[0224] For the second component (i.e., signaling support), several example embodiments based on the embodiments of component 1 are described below.

[0225] An example embodiment for UL signaling for DL reception with one CW per UE is as follows.

[0226] In one embodiment, the UE signals only one DL HARQ-ACK per component carrier (thus 1 bit). This 1-bit HARQ-ACK is transmitted by the UE via the UL control channel.

[0227] In another embodiment, the UE is configured to report CSI, which includes only one CQI component per subband (regardless of the recommended number of layers or rank). For wideband CQI (here, the term wideband CQI refers to a single CQI associated with a subband in the reporting set), if the rank indicator (RI) reports L as the recommended number of layers or rank, then it is assumed that the transmission spans L ≥ 1 layer to calculate that single CQI (per subband or subband in the reporting set).

[0228] In one embodiment related to "configurable layer mapping", uplink control information (UCI) includes representations of N CW，MAX The maximum N of CQI associated with CW CW，MAX CQI. N CW，MAX The value represents the maximum number of CWs that a UE can receive within a PDSCH allocation. In this case, depending on the value of RI, the number of CQIs in the UCI can be 1, 2, ..., or N. CW,MAX When the UE is configured to report subband CQI, the number of CQIs represents the number of CQIs in each subband. When the UE is configured to report wideband or partial band CQI, the number of CQIs represents the number of CQIs in the subbands within the configured reporting band.

[0229] In the above embodiments and variations, instead of signaling and / or configuring the UE to receive a maximum number N of CWs within a PDSCH allocation, CW，MAX The maximum total number of layers L across the CW can be notified and / or configured using signals. MAX This parameter can be signaled via higher-level (RRC) signaling or L1 / L2 control channels. In this case, depending on the value of RI, the number of CQIs in the UCI can be 1, 2, ..., or N. CW，MAX , where N CW，MAX Is with L MAX The number of associated CWs. When the UE is configured with subband CQI reporting, this number of CQIs represents the number of CQIs for each subband. When the UE is configured with wideband or partial band CQI reporting, this number of CQIs represents the number of CQIs for subbands within the configured reporting band.

[0230] When using signals to notify and / or configure the maximum total number of layers L across CW MAX The following is an example embodiment of a DL-related DCI design. In one example embodiment where 1-CW transmission is used for L≤4 and 2-CW transmission is used for L>4, if L MAX If L ≤ 4, then the UCI includes only one CQI, which corresponds to one CW. Otherwise, if L MAX> 4, the UCI includes one or two CQIs depending on the value of the RI, where each of the two CQIs corresponds to one of the two CWs. When the UE is configured with subband CQI reporting, the number of CQIs indicates the number of CQIs per subband. When the UE is configured with wideband or partial band CQI reporting, the number of CQIs indicates the number of CQIs for the subbands within the configured reporting band.

[0231] In the above embodiments and variations thereof, instead of signaling and / or configuring the maximum number of CWs N CW，MAX or the maximum number of layers L across the CWs MAX , a maximum number of CQIs in the UCI can be signaled and / or configured. For example, the maximum number of CQIs in the UCI can be configured to be 1 or 2. If the maximum number is 1, the number of CQIs in the UCI is 1. If the maximum number is 2, the number of CQIs in the UCI can be 1 or 2 depending on the value of the RI. For example, if the RI ≤ 4, only one CQI is reported in the UCI. If the RI > 4, two CQIs are reported in the UCI. When the UE is configured with subband CQI reporting, the number of CQIs indicates the number of CQIs per subband. When the UE is configured with wideband or partial band CQI reporting, the number of CQIs indicates the number of CQIs for the subbands within the configured reporting band.

[0232] When two CQIs (associated with two CWs) are reported, there can be several options. In a first option, two full CQIs (each CQI associated with one CW) are reported. In a second option, one of the CQIs is reported relative to the other CQI (e.g., in a differential manner) such that the CQI can be reported in fewer bits than the other CQI. When the UE is configured with subband CQI reporting, the number of CQIs indicates the number of CQIs per subband. When the UE is configured with wideband or partial band CQI reporting, the number of CQIs indicates the number of CQIs for the subbands within the configured reporting band.

[0233] An example implementation of DL signaling for DL reception with one CW per UE is as follows.

[0234] In one embodiment, a DL-related DCI (downlink control information) includes only one MCS parameter indicating the assigned MCS associated with a single TB or CW regardless of the number of layers. In addition, the DL-related DCI can include a set of HARQ-related parameters (such as new data indicator and / or redundancy version) associated with a single TB or CW regardless of the number of layers. If CB-level or CB group-level HARQ is supported, multiple sets of HARQ-related parameters can be included in the DL-related DCI. The UE receives this DL-related DCI via a DL control channel.

[0235] In another embodiment, if Figure 10 the value of K in embodiment 1000 is configurable, the parameter K is signaled to the UE via higher layer (RRC) signaling. Alternatively, the value of K can be dynamically configured via MAC control element (CE) or L1 DL control signaling.

[0236] In one embodiment related to "configurable layer mapping", the DL related DCI (downlink control information) includes N CW，MAX MCS fields, which represent the assigned MCSs associated with N CW，MAX CWs. The value of N CW，MAX is the maximum number of CWs that a UE can receive in one PDSCH / PUSCH allocation. In addition, the DL related DCI can include N CW，MAX groups of HARQ related parameters (such as new data indicator and / or redundancy version) associated with a single TB or CW, regardless of the number of layers. If CB level or CB group level HARQ is supported, the number of groups of HARQ related parameters included in the DL related DCI can be multiplied by the number of CBs or CB groups. The value of N CW，MAX can be configured via higher layer (RRC) signaling, MAC control element (MAC CE), or L1 DL control signaling (DL or UL related DCI). If configured via higher layer or MAC CE signaling, the UE first receives the configuration information. Then, the UE can determine the number of MCS and HARQ related fields in the received DL related DCI. If configured via L1 DL control signaling, the value of N CW，MAX can be signaled in the same DL related DCI as the N CW，MAX MCS fields and N CW，MAX HARQ related fields. Alternatively, the value of N CW，MAX can be implicitly detected by blindly decoding the DCI and inferring from the DCI size, which varies at least depending on the number of MCS and HARQ related fields. Alternatively, when L1 DL control signaling is used to configure the number of CWs, instead of signaling N CW，MAX , the number of CWs N CW itself is signaled - either explicitly in the DCI or implicitly detected from the DCI size (where the DCI includes N CW MCS fields and N CW HARQ related fields). Unlike N CW，MAX , N CW，MAX can vary in different DL allocations while N CW is configured.

[0237] As long as N CW，MAXIt is configurable, and the above embodiments apply.

[0238] In one sub-implementation of this embodiment, the total number L of layers across the CW is signaled in a single DCI field of the DL-related DCI.

[0239] In another sub-implementation of this embodiment, N will be used. CW，MAX The number of layers associated with each MCS and / or HARQ-related DCI field. The signal is used to notify a DCI field in the DL-related DCI. Therefore, there exists an indicator N. CW，MAX N of the number of layers in a CW CW,MAX There are several DCI fields. N can be configured as described above. CW,MAX The value of the parameter. This indicates the maximum number of layers per CW.

[0240] In another sub-implementation of this embodiment, N will be used. CW The number of layers associated with each MCS and / or HARQ-related DCI field. The signal is used to notify a DCI field in the DL-related DCI. Therefore, there exists an indicator N. CW N of the number of layers in a CW CW One DCI field. Parameters This indicates the maximum number of layers per CW.

[0241] In the above embodiments and variations, instead of signaling and / or configuring the UE to receive a maximum number N of CWs within a PDSCH allocation, CW,MAX The maximum total number of layers L across the CW can be notified and / or configured using signals. MAX This parameter can be signaled via higher-level (RRC) signaling or L1 / L2 control channels. Optionally, the maximum number of layers per CW can be signaled and / or configured. Similarly, this parameter can be signaled via higher-level (RRC) signaling or L1 / L2 control channels.

[0242] When using signals to notify and / or configure the maximum total number of layers L across CW MAX The following is an example embodiment of a DL-related DCI design. In one example embodiment where 1-CW transmission is used for L≤4 and 2-CW transmission is used for L>4, if L MAX If L ≤ 4, then the DCI includes one MCS field and / or a set of HARQ-related DCI fields, where a single MCS field and a single set of HARQ fields correspond to a CW. Otherwise, if L MAX>4, the DCI includes two MCS fields and / or two sets of HARQ related DCI fields, where each of the two MCS fields and each of the two sets of HARQ fields corresponds to one of the two CWs. In case L MAX >4 (maximum total number of layers configured for the UE) and L < 4 (total number of layers allocated for the UE in a particular / scheduled DL assignment), only one of the two MCS fields is used to indicate the MCS for one CW. The second MCS field can be used to signal other assumptions. In case L MAX >4 (maximum total number of layers configured for the UE) and L > 4 (total number of layers allocated for the UE in a particular / scheduled DL assignment), each of the two MCS fields is used to indicate the MCS for one of the two CWs.

[0243] Thus, for the same DL related DCI format, the number of MCS fields depends on the maximum total number of layers per PDSCH allocation per UE.

[0244] In the above embodiments and their variants, instead of signaling and / or configuring the maximum number of CWs N CW,MAX or the maximum number of layers L MAX across the CWs, the maximum number of MCS fields and / or the maximum number of sets of HARQ related DCI fields in the DL related DCI can be signaled and / or configured. For example, this maximum number can be configured to be 1 or 2. The maximum number of MCS fields and / or the maximum number of sets of HARQ related DCI fields can be configured jointly (as one common parameter) or separately.

[0245] Instead of a maximum number, the number of MCS fields and / or the number of sets of HARQ related DCI fields in the DL related DCI can be signaled and / or configured. This parameter can be signaled via higher layer (RRC) signaling or L1 / L2 control channels. For example, this number can be configured to be 1 or 2. The number of MCS fields and / or the maximum number of sets of HARQ related DCI fields can be configured jointly (as one common parameter) or separately.

[0246] When the number (or maximum number) of MCS fields and / or sets of HARQ related DCI fields in the DL related DCI is configured to be 2, while the number of allocated CWs (or layers) of the DL related DCI corresponds to one CW, only one of the two MCS fields is used to indicate the MCS for this one CW. The second MCS field can be used to signal other assumptions. When the number (or maximum number) of MCS fields and / or sets of HARQ related DCI fields in the DL related DCI is configured to be 2, while the number of allocated CWs (or layers) of the DL related DCI corresponds to two CWs, each of the two MCS fields is used to indicate the MCS for one of the two CWs.

[0247] An example implementation of DL signaling for UL transmission with one CW per UE is as follows.

[0248] In one embodiment, UL-related DCI (downlink control information) includes only one MCS parameter representing the assigned MCS associated with a single TB or CW, regardless of the number of layers. In addition, the UL-related DCI can include a set of HARQ-related parameters (such as new data indicator and / or redundancy version) associated with a single TB or CW, regardless of the number of layers. If CB-level or CB-group-level HARQ is supported, multiple sets of HARQ-related parameters can be included in the UL-related DCI. The UE receives this UL-related DCI via a DL control channel.

[0249] In one embodiment related to "configurable layer mapping", the UL-related DCI (downlink control information) includes N CW，MAX MCS fields representing the assigned MCS associated with N CW，MAX CWs. The value of N CW，MAX is the maximum number of CWs that a UE can receive in one PDSCH / PUSCH allocation. In addition, the DL-related DCI can include N CW，MAX sets of HARQ-related parameters (such as new data indicator and / or redundancy version) associated with a single TB or CW, regardless of the number of layers. If CB-level or CB-group-level HARQ is supported, the number of sets of HARQ-related parameters included in the DL-related DCI can be multiplied by the number of CBs or CB groups. The value of N CW，MAX may be configured via higher layer (RRC) signaling, MAC control element (MAC CE), or L1 DL control signaling (DL- or UL-related DCI). If configured via higher layer or MAC CE signaling, the UE first receives the configuration information. Then, the UE can determine the number of MCS and HARQ-related fields in the received DL-related DCI. If configured via L1 DL control signaling, the value of N CW，MAX may be signaled in the same DL-related DCI as the N CW，MAX MCS fields and N CW,MAX HARQ-related fields. Alternatively, the value of N CW，MAX may be detected implicitly by blindly decoding DCIs and inferring from the DCI size, which varies at least depending on the number of MCS and HARQ-related fields. Alternatively, when L1 DL control signaling is used to configure the number of CWs, instead of signaling N CW，MAX , the number of CWs N CWIt is itself—either explicitly signaled in the DCI or implicitly detected from the DCI size (where the DCI includes N). CW MCS fields and N CW (N HARQ related fields). CW,MAX The difference lies in configuring N. CW,MAX At the same time, N CW It can vary in different DL allocations.

[0250] As long as N CW,MAX It is configurable, and the above embodiments apply.

[0251] In one sub-example of this embodiment, the total number L of layers across the CW is signaled in a single DCI field in the UL-related DCI.

[0252] In another sub-implementation of this embodiment, N will be used. CW，MAX The number of layers associated with each MCS and / or HARQ-related DCI field. The signal is used to notify a DCI field in the DL-related DCI. Therefore, there exists an indicator N. CW，MAX N of the number of layers in a CW CW,MAX There are several DCI fields. N can be configured as described above. CW，MAX The value of the parameter. This indicates the maximum number of layers per CW.

[0253] In another sub-implementation of this embodiment, N will be used. CW The number of layers associated with each MCS and / or HARQ-related DCI field. The signal is used to notify a DCI field in the DL-related DCI. Therefore, there exists an indicator N. CW N of the number of layers in a CW CW One DCI field. Parameters This indicates the maximum number of layers per CW.

[0254] In the above embodiments and variations, instead of signaling and / or configuring the UE to receive a maximum number N of CWs within a PUSCH allocation, CW，MAX The maximum total number of layers L across the CW can be notified and / or configured using signals. MAX This parameter can be signaled via higher-level (RRC) signaling or L1 / L2 control channels. Optionally, the maximum number of layers per CW can be signaled and / or configured. Similarly, this parameter can be signaled via higher-level (RRC) signaling or L1 / L2 control channels.

[0255] When using signals to notify and / or configure the maximum total number of layers L across CW MAXAn example implementation of DL-related DCI design is as follows. In one example implementation where 1-CW transmission is used for L≤4 and 2-CW transmission is used for L>4, if L MAX ≤4, the DCI includes one MCS field and / or one set of HARQ-related DCI fields, where the single MCS field and the single set of HARQ fields correspond to one CW. Otherwise, if L MAX >4, the DCI includes two MCS fields and / or two sets of HARQ-related DCI fields, where each of the two MCS fields and each of the two sets of HARQ fields correspond to one of the two CWs. In the case of L MAX >4 (the maximum total number of layers configured for the UE) and L≤4 (the total number of layers allocated for the UE in a particular / scheduled DL assignment), only one of the two MCS fields is used to indicate the MCS for that one CW. The second MCS field can be used to signal other assumptions. In the case of L MAX >4 (the maximum total number of layers configured for the UE) and L>4 (the total number of layers allocated for the UE in a particular / scheduled DL assignment), each of the two MCS fields is used to indicate the MCS for one of the two CWs.

[0256] Therefore, for the same DL-related DCI format, the number of MCS fields depends on the maximum total number of layers per PUSCH allocation per UE.

[0257] In the above embodiments and their variants, instead of signaling and / or configuring the maximum number of CWs N CW，MAX or the maximum number of layers L MAX across CWs, the maximum number of MCS fields and / or the maximum number of sets of HARQ-related DCI fields in the DL-related DCI can be signaled and / or configured. For example, this maximum number can be configured to be 1 or 2. The maximum number of MCS fields and / or the maximum number of sets of HARQ-related DCI fields can be configured jointly (as one common parameter) or separately.

[0258] Instead of the maximum number, the number of MCS fields and / or the number of sets of HARQ-related DCI fields in the UL-related DCI can be signaled and / or configured. This parameter can be signaled via higher layer (RRC) signaling or L1 / L2 control channels. For example, this number can be configured to be 1 or 2. The number of MCS fields and / or the maximum number of sets of HARQ-related DCI fields can be configured jointly (as one common parameter) or separately.

[0259] When the number (or maximum number) of MCS fields in UL-related DCI and / or the number of groups of HARQ-related DCI fields is configured to be 2 while the assigned number of CWs (or layers) of UL-related DCI corresponds to one CW, only one of the two MCS fields is used to indicate the MCS of the one CW. The second MCS field can be used to signal other assumptions. When the number (or maximum number) of MCS fields in UL-related DCI and / or the number of groups of HARQ-related DCI fields is configured to be 2 while the assigned number of CWs (or layers) of UL-related DCI corresponds to two CWs, each of the two MCS fields is used to indicate the MCS of one of the two CWs.

[0260] In the above embodiments, two separate parameters of the maximum total number of layers (or maximum number of CWs) can be used for DL and UL, respectively.

[0261] For UL, the number or maximum number of MCS fields and / or HARQ-related DCI fields can be fixed to be 1. This is applicable, for example, when the maximum number of layers that can be supported on UL corresponds to 1-CW transmission.

[0262] The following embodiments of component 2 relate to the enhanced UL and UL signaling support described in component 1 when the number of transmission layers L exceeds a certain value and the number of CWs of the transmission is 2.

[0263] In the case of UL signaling for DL reception, the UE signals DL HARQ-ACK and CSI report (which includes CQI) per DL component carrier. In the case of DL signaling for DL reception, the DL-related DCI (downlink control information) includes at least one MCS (modulation and coding scheme) field and HARQ-related parameters (such as new data indicator and / or redundancy version) for PDSCH allocation per UE. If CB-level or CB-group-level HARQ is supported, multiple groups of HARQ-related parameters can be included in the DL-related DCI. In the case of DL signaling for UL transmission, the UL-related DCI (downlink control information) includes at least one MCS (modulation and coding scheme) field and HARQ-related parameters (such as new data indicator and / or redundancy version) for PUSCH allocation per UE. If CB-level or CB-group-level HARQ is supported, multiple groups of HARQ-related parameters can be included in the DL-related DCI.

[0264] When the UE is configured to receive 1-CW transmission (per PDSCH / PUSCH allocation per UE), for example when 1 < L < xi, several embodiments can be used.

[0265] In one embodiment 1A, the UE signals only one DL HARQ-ACK (thus 1 bit) per component carrier. This 1-bit HARQ-ACK is signaled by the UE via the UL control channel.

[0266] In another embodiment 1B, the UE can report CSI which includes only one CQI component per subband (as well as an RI report from {1, 2,..., x1}). For wideband CQI (here, the term wideband CQI refers to a single CQI associated with the subbands in the reporting set), only one CQI corresponding to the layers is reported. If the rank indicator (RI) reports L as the recommended number of layers or rank, the single CQI (per subband or subbands in the reporting set) is calculated assuming the transmission across L > 1 layers.

[0267] In another embodiment 1C, the UE receives a DL-related DCI (downlink control information) which includes only one MCS parameter representing the assigned MCS associated with a single TB or CW. In addition, the DL-related DCI can include a set of HARQ-related parameters (such as new data indicator and / or redundancy version) associated with the single TB or CW regardless of the number of layers. If CB-level or CB-group-level HARQ is supported, multiple sets of HARQ-related parameters can be included in the DL-related DCI. The UE receives this DL-related DCI via the DL control channel.

[0268] In another embodiment 1D, the UE receives a UL-related DCI (downlink control information) which includes only one MCS parameter representing the assigned MCS associated with a single TB or CW. In addition, the UL-related DCI can include a set of HARQ-related parameters (such as new data indicator and / or redundancy version) associated with the single TB or CW regardless of the number of layers. If CB-level or CB-group-level HARQ is supported, multiple sets of HARQ-related parameters can be included in the UL-related DCI. The UE receives this UL-related DCI via the DL control channel.

[0269] Each of the above embodiments (1A, 1B, 1C, and 1D) can be used individually or in combination with at least another embodiment when the UE is configured to receive 1-CW transmission per PDSCH / PUSCH allocation.

[0270] When the UE is configured to receive 2-CW transmission (per PDSCH / PUSCH allocation per UE), two cases can apply, for example, when L > x2. The first case is to configure CW cycling or layer cycling (ON). The second case is to not configure CW cycling and layer cycling (OFF).

[0271] In the first case, embodiments 1A, IB, 1C and / or ID can be used. That is, when using a CW cycle or a layer cycle, one MCS DCI field, one CQI, one HARQ-related DCI field and one DL HARQ-ACK feedback can be used even if the number of CWs is two. This is because each CW is mapped across layers. Alternatively, when using a CW cycle or a layer cycle, one MCS DCI field (associated with both CWs), one CQI (associated with both CWs), two HARQ-related DCI fields (each associated with a CW) and two DL HARQ-ACK feedbacks (each associated with a CW) can be used. Alternatively, when using a CW cycle or a layer cycle, two MCS DCI fields (each associated with a CW), two CQIs (each associated with a CW), one HARQ-related DCI field (associated with both CWs) and one DL HARQ-ACK feedback (associated with both CWs) can be used.

[0272] In the second case, several embodiments can be used.

[0273] In one embodiment 2A, the UE signals two DL HARQ-ACKs per component carrier (thus 2 bits per CW). The UE transmits the 2-bit HARQ-ACK via an UL control channel.

[0274] In another embodiment 2B, the UE can report CSI, which includes two CQI components per subband (each component representing one CW, and an RI report taking values from {x2+1, x2+2,..., L MAX} for a wideband CQI (here, the term wideband CQI refers to two CQIs, each CQI associating a CW with a subband in the reporting set), two CQIs are reported, each CQI corresponding to a CW with its associated layers. If a rank indicator (RI) reports L as the recommended number of ranks or ranks, the two CQIs (per subband or subband in the reporting set) are calculated assuming transmission across L > 1 layers. The two CQIs can also be differentially encoded with respect to a reference or with respect to each other.

[0275] In another embodiment 2C, the UE receives a DL-related DCI (downlink control information) that includes two MCS parameters representing the MCS associated with the allocation of two TBs or CWs. In addition, the DL-related DCI can include two sets of HARQ-related parameters (such as new data indicators and / or redundancy versions) associated with the two TBs or CWs. If CB-level or CB-group-level HARQ is supported, multiple sets of HARQ-related parameters can be included in the DL-related DCI. The UE receives the DL-related DCI via a DL control channel.

[0276] In one embodiment 2D, the UE receives a UL-related DCI (downlink control information) that includes two MCS parameters representing the assigned MCS associated with two TBs or CWs. In addition, the UL-related DCI can include two sets of HARQ-related parameters (such as new data indicator and / or redundancy version) associated with the two TBs or CWs. If CB-level or CB-group-level HARQ is supported, multiple sets of HARQ-related parameters can be included in the UL-related DCI. The UE receives this UL-related DCI via a DL control channel.

[0277] Each of the above embodiments (2A, 2B, 2C, and 2D) can be used individually or in combination with at least another embodiment when the UE is configured to receive 2-CW transmission per PDSCH / PUSCH allocation.

[0278] With reference to embodiments I and II of component 1, if x1 = x2, the switching between 1-CW and 2-CW transmission can occur dynamically depending on the number of layers L scheduled by the gNB / NW for the UE for PDSCH / PUSCH allocation. On the other hand, if x1 > x2 (so for x2 < L < x1, either 1-CW or 2-CW transmission can be configured), the switching between 1-CW and 2-CW transmission (when x2 < L < x1) can be performed by the gNB / NW for the UE via higher layer (e.g., RRC) signaling, via MAC-CE, or via L1 DL control signaling (using DCI).

[0279] In more configurable embodiments, the values of x1 and / or x2 can also be configured by the gNB / NW for the UE. Such configuration can be performed via higher layer (e.g., RRC) signaling.

[0280] For embodiment III and its sub-embodiments, to support DL reception in the manner described in Table 2, a CSI report including the recommended correspondence (between 2 CWs and L layers) can be used. Since the recommended number of layers is signaled via RI, a CSI report parameter indicating the recommendation for L0 can be added (so L1 can be inferred from L - L0). In addition to the DCI field indicating the number of layers L, the associated DL-related DCI can also include a DCI field indicating L0. Likewise, to support UL reception in the manner described in Table 2, in addition to the DCI field indicating the number of layers L, the associated DL-related DCI can also include a DCI field indicating L0.

[0281] In LTE, the following can be used: Figure 11Bit and symbol level processing is shown in embodiment 1100. A transport block (TB) 1101 is processed by the following series of bit level operations 1102: code block (CB) segmentation (step 1103), channel coding, rate matching, and channel interleaver (for UL only). For CB segmentation, if the length L TB >6144, then the TB of length L TB is segmented into C≥1 CBs. If C=1, then only a 24-bit TB-CRC is inserted. If C>1, then a 24-bit TB-CRC is first added before CB segmentation, and then a 24-bit CB-CRC is inserted at the end of each CB. Thus, for C>1, both TB-CRC and CB-CRC are inserted. Note that TB-CRC and CB-CRC have different generator polynomials. To minimize the number of padding bits, two values of the maximum CB length K + and K - are used. Thus, in most cases, when C>1, some CBs can be of length K - and other CBs can be of length K + . For channel coding, a set of allowed CB lengths (defined for the Turbo QPP interleaver) and a rate 1 / 3 Turbo code (PCCC) with an 8-state constituent encoder are used. Since Turbo codes are based on convolutional codes, it does not have a built-in error detection function. For rate matching, equal interleaving and puncturing is performed on each of the 3 Turbo output streams. This is achieved using 3 identical rectangular sub-block interleavers (one interleaver per Turbo output stream), bit collection, followed by bit selection / pruning via a circular buffer, and CB concatenation to form a codeword (CW). The output of the bit level processing 1104 associated with one TB and one CW is then processed by the following series of symbol level operations 1105: modulation mapping, layer mapping (1106), precoding, and RE mapping.

[0282] For 5G NR, at least three aspects of bit-level processing and symbol-level processing can differ from LTE. First, with the low-density parity-check (LDPC) code (and potentially polar code for control transmission) used for data transmission, the channel coding scheme employed has inherent (“free”) error detection capability per CB. This is especially true for the LDPC code, as syndrome decoding (an inherent property of block codes) can be used. However, the error detection performance associated with syndrome decoding can depend on the CB size. This can impact the design of CB segmentation (especially CRC insertion). Second, the LDPC code can have different output stream properties than the Turbo code (e.g.: with a 3-stream design, the first and second parity check output streams of the LDPC are directly related to each other). This impacts the design of rate matching, as it needs to ensure proper puncturing. Third, a more efficient layer mapping scheme can be employed. While beneficial to facilitate modulation and coding scheme (MCS) adaptation per codeword (CW) and MMSE-SIC (MMSE with successive interference cancellation) receivers, it incurs some significant overhead over single CW mapping. DL overhead comes from the additional DCI payload from 2 fixed MCS fields and 2 fixed NDI-RV (DL HARQ related) fields. UL overhead comes from two CQIs for rank > 1 (all 4 bits + delta 3 bits for wideband CQI, and 2x overhead for subband CQI) and the need for two DL HARQ-ACKs for rank > 1. In addition to this, there is also the complexity of having to accommodate more than one layer mapping scheme in case of retransmission. Therefore, an improved scheme of having a single CW per UE for both DL and UL can be beneficial. This will impact CB segmentation (especially CB formation and padding bits), and potentially rate matching.

[0283] In view of the above new challenges for 5G NR systems, there is a need to design new bit-level processing and symbol-level processing, in particular CB segmentation and rate matching.

[0284] The present disclosure includes the following components. The third component relates to CRC insertion for CB segmentation. The fourth component includes CB formation for CB segmentation. The fifth component includes a solution for CB concatenation. Each component can be used individually (without using other components) or in combination with at least one of the other components. Also, each component includes multiple sub-components. Each sub-component can be used individually (without using any other sub-component) or in combination with at least one other sub-component.

[0285] Each of these components, including the components described above, can be used alone (without use of other components) or in combination with at least one of the other components. Also, each of these components includes a plurality of sub-components. Each sub-component can be used alone (without use of any other sub-component) or in combination with at least one other sub-component.

[0286] For the third component (i.e., CRC insertion for CB segmentation), the codeword (CW) originates from a transport block (TB). Depending on the size of the TB, the TB can be segmented into one or more code blocks (CBs) in order to limit the channel decoding latency at the UE. For example, one CB can be decoded and facilitate early detection of TB decoding failure (thus enabling fast CB-level HARQ). Figure 11 Embodiment 1100 illustrates the process of CB segmentation, where a TB 1101 is divided into a number of CBs (with the special case of one CB when the TB size is small) 1102. Given the number of layers L, the selected MCS, the resource allocation, and possibly some other transmission parameters, CB segmentation 1110 can include at least one of the following functions: segmentation of the TB into one or more CBs, padding (to ensure a certain CB size before channel coding), introduction of CRC bits per CB (referred to as CB-CRC in this disclosure). In addition, TB-CRC bits can be added at 1101 (before segmentation, as in LTE) or at 1102 (after segmentation and / or insertion of CB-CRC).

[0287] Several embodiments are described as follows. In the following description, the length / size of CRC, CB, and TB are defined in terms of number of bits.

[0288] In one embodiment, a CB-CRC is inserted for each CB of the CBs for C > 1. When C = 1, the CB-CRC is functionally equivalent to a TB-CRC. In this embodiment, the length of the CB-CRC can be selected from a set of multiple (M > 1) values, i.e., N CB-CRC ∈ {N0, N1,..., N M-1}, where N i < N i+1 (i = 0, 1,..., M - 1). This variable length CB-CRC can be used for data transmission (UL and DL) only, or for data as well as control transmission (UL and / or DL). The motivation of this embodiment is the fact that LDPC has inherent error detection capability that can be used in conjunction with the CB-CRC. Thus, N CB-CRC can be selected by taking this into account. For example, since LTE uses a 24-bit CB-CRC, N M-1 may be further reduced. For example, N CB-CRCIn addition, the error detection performance (measured in terms of error pass rate and / or false alarm rate) depends on the CB length. In particular, the error detection performance from the syndrome decoding improves as the CB size increases. For example, for a CB size of 117, an error pass rate of < 2 –7 ( which is comparable to a 7-bit CRC) can be achieved by the syndrome decoding of the LDPC code. For a CB size of 1000, an error pass rate of < 2 –10 ( which is comparable to a 10-bit CRC) can be achieved by the syndrome decoding of the LDPC code.

[0289] In the following description, the CB size N CB may be defined as including the CB-CRC or without (before insertion) the CB-CRC.

[0290] In one sub-embodiment, the length of the CB-CRC for data transmission can be configured via higher layer (RRC) signaling for each UE. The RRC parameter is then used to indicate N CB-CRC . Alternatively, the length of the CB-CRC for data transmission can be dynamically configured via MAC control element (MAC CE) or L1 DL control signaling.

[0291] In another sub-embodiment, the length of the CB-CRC for data transmission can depend on the CB size N CB . For example, using M possible values N CB-CRC ∈ {N0, N1,..., N M-1}, the following rules can be used.

[0292]

[0293] The thresholds of CB sizes {K0, K1,..., K M-1} (where K i < K i+1 (i = 0, 1,..., M - 1}) are used to define the range of different N CB-CRC values. The value of M, the values of the set {K0, K1,..., K M-1}, and / or the set of values for N CB-CRC ∈ {N0, N1,..., N M-1} can be configurable (e.g., via higher layer / RRC signaling or MAC CE or L1 DL control) or fixed in the specification.

[0294] From the UE’s perspective, the CB size can be inferred from the DCI fields (in the DL assignment or UL grant) including the MCS index and / or the TB size N TB . The TB size N TBThe CB size N TB may be inferred from the CB segmentation. The number of CBs C and the CB size N CB may be inferred from the CB segmentation.

[0295] In one example of the above sub-embodiment, M is 2 and {N0, N1} = {16, 24}. In another example, M is 2 and {N0, N1} = {16, 20}. In another example, M is 2 and {N0, N1} = {12, 20}. In another example, M is 2 and {N0, N1} = {8, 16}. In another example, M is 3 and {N0, N1, N2} = {16, 20, 24}. In another example, M is 3 and {N0, N1, N2} = {12, 16, 20}. In another example, M is 3 and {N0, N1, N2} = {8, 12, 16}. In another example, M is 4 and {N0, N1, N2, N3} = {12, 16, 20, 24}. In another example, M is 4 and {N0, N1, N2, N3} = {8, 12, 16, 20}.

[0296] In a variant of the previous sub-embodiment, the length N CB-CRC of the CB-CRC M-1 may also depend not only on the CB size N CB but also on the modulation and coding rate. From the UE’s perspective, as mentioned above, the CB size can be inferred from the DCI fields (in the DL assignment or UL grant) including the MCS index and / or the TB size N TB . The TB size N TB may be inferred from the MCS index and the resource (PRB) allocation. The number of CBs C and the CB size N TB may be inferred from the CB segmentation. CB (see component 2 in this disclosure). The modulation and coding rate can be inferred from the MCS index and / or the resource (PRB) allocation.

[0297] As mentioned above, when C = 1, the CB-CRC is functionally equivalent to the TB-CRC. In another embodiment, in addition to inserting the CB-CRC as described in the previous embodiment, when the number of CBs C associated with the TB is greater than a threshold C min (C > C min ), the TB-CRC is also inserted before the CB segmentation. Otherwise (when C ≤ Cmin), only the CB-CRC is inserted (one CB-CRC per CB). The rationale of this embodiment is to provide more protection when the number of CBs is large enough (which means a larger TB size). C minThe value can be configurable (e.g., controlled by higher-level / RRC signaling, MAC CE, or L1 DL) or fixed in the specification.

[0298] A CB group is defined as multiple Cs within a TB. GROUP The number of CBs (whether consecutive or sequential) is 1. When a CB group comprises C CBs associated with a TB, the CBG-CRC is essentially a TB-CRC. In another embodiment, in addition to inserting the CB-CRC described in the previous embodiment, when the number of CBs in the CB group is C... GROUP Greater than threshold C GROUP,min (C GROUP >C GROUP,min When ), a CB group CRC (CBG-CRC) is inserted before the CB segment. Otherwise (when C GROUP ≤C GROUP,min (At that time), only CB-CRC is inserted (one CB-CRC for each CB). C GROUP,min The value can be configurable (e.g., controlled via higher-level / RRC signaling, MAC CE, or L1DL) or fixed in the specification. CBG-CRC can be used with or without TB-CRC.

[0299] For the fourth component (i.e., CB formation of CB segments), consider two types of CW-to-layer mapping (or layer mapping) schemes for a single CW: symbol-level and CB-level layer mapping. Using frequency-priority (rather than time-priority) vertical mapping as an example, symbol-level and CB-level layer mappings can be described as follows. For those skilled in the art, extensions to horizontal or diagonal mappings and time-priority mappings are straightforward. Similarly, symbol-level and CB-level vertical mappings can be used for different conditions (e.g., depending on the number of CBs C and / or the number of layers L).

[0300] Several embodiments of CB segmentation for symbol-level and CB-level layer mapping are described below. In the following embodiments, the CB size N CB (Bits) are defined to include CB-CRC. The extension without CB-CRC (before insertion) is self-evident to those skilled in the art. Similarly, TB size N TB (Bits) are defined to include TB-CRC. The extension for the case without TB-CRC (before insertion) is straightforward to those skilled in the art. Any of the following embodiments applies to designs with or without TB-CRC (inserted before CB segmentation), and designs with or without CBG-CRC (inserted before CB segmentation). In the following description, the length / size of CRC, CB, and TB is defined in terms of the number of bits.

[0301] In one embodiment I (especially applicable to symbol level mapping, although applicable to CB level mapping as well), the same CB size N CB (bit) for C CBs {CB 0, CB 1, …, CB C-1} associated with the same TB. Denote the maximum CB size as N CB，MAX , the number of CBs C associated with a TB of length N TB can be calculated as follows. If N TB ≤ N CB,MAX , then C = 1. The CB size N CB may be set to the minimum supported CB size for channel coding (e.g., LDPC for data transmission) such that Otherwise, if N TB > N CB,MAX , define and C - = C + - 1. Also define K + as the minimum supported CB size for channel coding (e.g., LDPC for data transmission) such that C can then be determined as described in equation (17). The CB size N CB may be set to N CB = K + .

[0302]

[0303] The value of N CB,MAX may be configurable (e.g., through higher layer / RRC signaling or MAC CE or L1 DL control) or fixed in the specification. The value of N CB,MAX may be one of the supported CB sizes for channel coding (e.g., LDPC for data transmission).

[0304] The number of padding bits can be calculated according to equation (18). The padding bits can be set to <null>Assuming a value of 0 for CRC calculation) and inserted at predetermined locations (e.g., local locations at the start of a TB, or distributed / scattered throughout the TB).

[0305] N FILLER = C x N CB -N TB (Formula 18)

[0306] In another embodiment II (particularly suitable for CB-level mapping, although also suitable for symbol-level mapping), the same CB size N CB is used for the C CBs {CB 0, CB 1,..., CB C-1} associated with the same TB. However, the number of transmission layers L is also used to determine the number of CBs C and the CB size N CB in a TB. In particular, the total number of CBs C is chosen to be an integer multiple of L. That is, C = μL, where μ is at least 1. The maximum CB size is denoted as N CB,MAX , and the number of CBs C (= μL) associated with a TB of length N TB can be calculated as follows. If L = 1 and N TB ≤ N CB,MAX , then C = 1. The CB size N CB may be set to the smallest supported CB size for channel coding (e.g., LDPC for data transmission) such that Otherwise, define and C - = C + -L. K + is also defined as the smallest supported CB size for channel coding (e.g., LDPC for data transmission) such that C can then be determined as described in Formula (19). The CB size N CB may be set to N CB = K + .

[0307]

[0308] The value of N CB,MAX may be configurable (e.g., through higher layer / RRC signaling or MAC CE or L1 DL control) or fixed in the specification. The value of N CB,MAX may be one of the supported CB sizes for channel coding (e.g., LDPC for data transmission).

[0309] The number of padding bits can be calculated according to Formula (20). The padding bits can be set to <null>(assuming a value of 0 for CRC computation) and inserted at predetermined locations (e.g., local locations at the start of a TB, or distributed / sprinkled throughout the TB).

[0310] N FILLER = C x N CB -N TB (Formula 20)

[0311] In another embodiment III (particularly suitable for CB-level mapping, although also suitable for symbol-level mapping), two CB sizes N CB，- and N CB，+ are used for the first C - CBs and the next C + CBs from the same TB, respectively. The number of transmission layers L is also used to determine the number of CBs and the CB size. Let the maximum CB size be denoted as N CB，MAX , the number of CBs and the CB size can be calculated as follows. If L = 1 and N TB ≤ N CB,MAX , then C + = 1 and C _ = 0. The CB size N CB may be set to the minimum supported CB size for channel coding (e.g., LDPC for data transmission) such that Otherwise, define K + as the minimum supported CB size for channel coding (e.g., LDPC for data transmission) such that K _ as the maximum supported CB size for channel coding (e.g., LDPC for data transmission) such that Then, the number of CBs and the CB size can be calculated in Formula (21).

[0312]

[0313] C + = C TOT - C - , N CB,+ = K + Formula (21)

[0314] The value of N CB，MAX may be configurable (e.g., through higher layer / RRC signaling or MAC CE or L1 DL control) or fixed in the specification. The value of N CB，MAX may be one of the supported CB sizes for channel coding (e.g., LDPC for data transmission).

[0315] The number of padding bits can be calculated according to Equation (22). The padding bits can be set to <null>(Assuming a value of 0 for CRC calculation) and insert at a predetermined location (e.g., a local location at the beginning of the TB, or distributed / scattered throughout the TB).

[0316] N FILLER =C - ×N CB,- +C + ×N CB,+ -N TB Formula (22)

[0317] In a variant (III-B) of Embodiment III, formula (21) can be replaced by formula (23), while the other components strictly follow the description of Embodiment III. Formula (23) guarantees that, at least for a given value of n, {CBn, CBn+1, ..., CBn+L-1} share the same CB size B. n (Code element). However, the size of CB can vary for different values ​​of n.

[0318]

[0319] C + =C TOT -C - N CB,+ =K + Formula (23)

[0320] For the fifth component (i.e., CB concatenation), after each CB rate match, CBs from the same TB are concatenated to form a codeword (CW) – which is later mapped to a sequence of QAM symbols. In LTE, a simple concatenation scheme is used, stacking CBs into a single sequence. For NR, the expected transmission bandwidth is much larger, especially for >6 GHz. In this case, when a large TB comprising many CBs is mapped onto allocated resources (RBs), it is beneficial to ensure that the QAM symbols (and thus bit sequences) from each CB are mapped across the allocated transmission bandwidth. By doing so, each CB can experience a roughly similar frequency-selective channel, which reduces the risk of losing some CBs due to deep channel fading.

[0321] Therefore, bit-level interleavers or symbol-level interleavers can be added to CB concatenation operations (before or after stacking CBs from the same TB) so that bits or symbols from each CB can be spread across the allocated transmission bandwidth (instead, for example, confined to a limited set of RBs in the frequency domain).

[0322] Two main criteria can be used to design the interleaver: 1) When mapping to allocated RBs within a time slot / subframe, the CB should occupy the minimum number of OFDM symbols. This is to ensure minimal CB decoding latency. 2) When mapping to allocated RBs within a time slot / subframe, the CB should be distributed across the allocated PRBs as much as possible. Therefore, the CB should be mapped as narrowly as possible in the time domain but as widely as possible in the frequency domain.

[0323] Some example implementations of the CB cascade scheme are given below.

[0324] Let S represent the number of bits per CB after rate matching and the number of CBs within a TB / CW. CB,bit (Assuming the length of each CB is the same) and C, define the number of segments N for each CB. seg Divide the number of bits per CB by the modulation order (Q = number of bits per modulation symbol, i.e., 2 for QPSK, 4 for 16QAM, 6 for 64QAM, and 8 for 256QAM) and the number of TB / CW layers L:

[0325]

[0326] The number of segments in each CB represents the number of modulation symbols per layer in each CB. It can be assumed that CB segmentation and / or rate matching ensure S... CB,bit It is an integer multiple of QL. This is in Figure 12 As shown in Figure 1200, TB 1210 comprises C CBs. The first CB (CB0, 1220) is segmented into N segments. seg Each part consists of QL bits (e.g., part 1221). Furthermore, the number of OFDM symbols per slot / subframe and the number of REs / subcarriers associated with the allocated RB (per OFDM symbol) are respectively represented as M. OFDM and M RE For example, for an NR slot comprising 14 OFDM symbols with 4 allocated RBs (each RB having 12 REs / subcarriers), M OFDM =14 and M RE =48. Additionally, define the following parameters:

[0327]

[0328] If μ = 0, then even if the RE / subcarrier in the allocated RB is used, a CB will occupy more than one OFDM symbol. Conversely, if μ ≥ 0, then a CB can occupy at least one OFDM symbol.

[0329] For the following example embodiment, it is assumed that C CBs from a TB / CW have the same size. This can be extrapolated by those skilled in the art to the use of two CB sizes (e.g., in LTE). In one example, if two CB sizes are used (e.g., in LTE), the smaller CB size (S) can be used as the basis for the calculation. CB,bit - To calculate the parameter (N) in formulas (24) and (25) seg , and α). In another example, if two CB sizes are used (e.g. in LTE), the larger CB size (S) can be used as the basis. CB,bit + To calculate the parameter (N) in formulas (24) and (25) seg , and α).

[0330] In one embodiment (I), CB concatenation can be performed as follows. When μ ≤ x (where x is an integer), a CB concatenation scheme referred to herein as scheme A is used. Scheme A can be described as follows. All C CBs associated with a TB / CW are stacked together without any interleaving operation, as follows. Figure 12 As shown in 1210. When μ>x (where x is an integer), a CB cascading scheme referred to in this disclosure as Scheme B is used. Scheme B can be described as follows. A set of indices associated with the c-th CB (c = 0, 1, ..., C-1) is represented as Where σ c,s Corresponding to the c-th CB and the s-th segment (s = 0, 1, ..., N) seg -1). Define its elements as σ. c of The length is N seg The row vectors and α multiplied by The matrix ∑ is as follows:

[0331]

[0332] Note that when mod(C,α)=z≠0, the vector It consists of padding bits, each padding bit having a value. <null>The interleaver π can then be described as follows, which is described as a row vector of length CN seg read in a "row first, column second" fashion. The vec(X) operation stacks the elements of the matrix X in a row-major order (followed by across columns) to create a column vector.

[0333]

[0334] After the operations in equation (27), the padding bits at the end can be removed ( <null>value).

[0335] It is evident from Equation (27) that the interleaver π introduces a separation of (α-1) symbols between two consecutive modulated symbols in the CB. Since α is determined according to Equation (26), the interleaver allows each CB to efficiently span the entire allocated RB using the minimum possible number of OFDM symbols (to maximize frequency diversity).

[0336] The aforementioned interleaver π operates at the bit level, but interleaves each of the QL streams in the same way. This is in Figure 13 As shown in Figure 1300. (Reference) Figure 12 The segmentation operation in the middle (where each segment, for example 1221, consists of QL bits representing bits within each layer of modulation symbols), each of the QL bit streams (each stream includes N) seg Bit, see Figure 12 In equation (27), 1210 and 1220 are interleaved using the same interleaver π (1310) described in equation (27). After applying the QL parallel interleaving operation, QL bitstreams are collected into a stream similar to... Figure 12 In a stream of 1210 and 1220.

[0337] Figure 13 The order of operations can be described as follows. The nth bit associated with the cth CB is represented as b. c,n After CB concatenation, the bitstream associated with the TB / CW comprising C CBs can be described as follows:

[0338]

[0339] The bitstream can then be rearranged into QL streams as follows (Equation (15)). The i-th row of matrix B (represented by β in Equation (29)) i ) corresponds to Figure 13 The i-th bit stream (i = 0, 1, ..., QL-1) in the data.

[0340]

[0341] Interweaving each bitstream (producing interleaved bitstream β) i After (π), the bit collection operation can be described as follows:

[0342]

[0343] In a variation of the above example embodiment, the interleaving operation in Scheme B (including equations (26), (27), (28), (29), and (30)) can also be implemented as a block or rectangular bit interleaver. For example, the ∑ in equation (26) describes a block interleaving operation, where the ith stream of bits β i is written (e.g., into memory or a shift register bank) column-wise (column-first) and then read (e.g., from memory or a shift register bank) row-wise (row-first) according to the arrangement in equation (26). The number of rows and columns in the block interleaver is determined by the number of CBs, the CB size, and the number of allocated RBs. Alternatively, the block or rectangular interleaver ∑ in equation (26) can be implemented as a bit group interleaver, where the interleaver operates on a group of QLbits (rather than 1 bit) at a time. In this case, the streams of bits b grouped into units of QLbits are written (e.g., into memory or a shift register bank) column-wise (column-first) and then read (e.g., from memory or a shift register bank) row-wise (row-first) according to the arrangement in equation (26).

[0344] To illustrate the operation of Scheme B, in one example the values of a, C, and N seg are assumed to be 2, 4, and 3, respectively. Thus, in this example, the interleaver is given as follows.

[0345] π = [σ 0,0 , σ 1,0 , σ 0,1 , σ 1,1 , σ 0,2 , σ 1,2 , σ 2,0 , σ 3,0 , σ 2,1 , σ 3,1 , σ 2,2 , σ 3,2 ] equation (31)

[0346] Using an input stream of length CN seg

[0347] β i = {β i,0,0 , β i,0,1 , β i,0,2 , β i,1,0 , β i,1,1 , β i,1,2 , β i,2,0 , β i,2,1 , β i,2,2 , β i,3,0 , β i,3,1 , β i,3,2},

[0348] The resulting bit stream after interleaving is ​

[0349] β i (π) = {β i,0,0 , β i,1,0 , β i,0,1 , β i,1,1 , β i,0,2 , β i,1,2 , β i,2,0 , β i,3,0 , β i,2,1 , β i,3,1 , β i,2,2 , β i,3,2}

[0350] In a sub-embodiment of this embodiment, the value of x is set to 0. In another sub-embodiment, the value of x is set to 1. In yet another sub-embodiment, the value of x can be configured semi-statically (via higher layer signaling) or dynamically (via L1 or L2 control signaling) for each UE.

[0351] In another embodiment (II), CB concatenation can be done as follows. The condition for using scheme A and scheme B is based on the channel bandwidth (e.g., system bandwidth) - associated with the cell / TRP / gNB or associated with the UE. For example, if the channel bandwidth (or system bandwidth) is less than or equal to a certain value (e.g., 20 MHz), scheme A is used. Otherwise, if the channel bandwidth (or system bandwidth) is greater than a certain value (e.g., 20 MHz), embodiment I is used (i.e., if the number of allocated RBs is large enough relative to the CB size N seg , scheme B can be used).

[0352] In another embodiment (III), CB concatenation can be done as follows. The condition for using scheme A and scheme B is based on the resource allocation (RA) signaled in the DL or UL related DCI (associated with DL or UL assignment, respectively). For example, if the frequency span of the RA (difference between the highest RE / subcarrier index and the lowest RE / subcarrier index) is equivalent to a value less than or equal to a certain value (e.g., 20 MHz), scheme A is used. Otherwise, embodiment I is used (i.e., if the number of allocated RBs is large enough relative to the CB size N seg , scheme B can be used).

[0353] In the above embodiments and sub-embodiments (I, II, and III), the bit stream b is split into QL streams, where each of the QL streams is interleaved with the same interleaver π of length CN seg . Thus, the number of segments per CB is In a variant of these embodiments, the bit stream b is split into Q streams, where each of the Q streams is interleaved with the same interleaver π' of length CN' seg , where Thus, In yet another variant of these embodiments, the bit stream b is not split into streams and is interleaved with an interleaver π'" of length CS seg Thus, In yet another variant of these embodiments, the bit stream b is not split into streams and is interleaved with an interleaver π'" of length CS CB,bit

[0354] Figure 14 A flowchart illustrating an example method 1400 in which a UE receives a multi-layer data transmission, in accordance with embodiments of the present disclosure, is shown. For example, method 1400 can be performed by UE 116.

[0355] Method 1400 begins with the UE receiving an L-layer data transmission, where the data transmission is composed of at least one code block (CB), and the CB includes a cyclic redundancy code (CRC) of length N. The length N of the CRC is a function of the length of the CB, and the length corresponds to a number of bits. Additionally, the UE receives a downlink control information (DCI) associated with the data transmission (step 1401). When L is less than or equal to a threshold, the data transmission includes one codeword (CW), otherwise two CWs. For example, the threshold can be fixed at 4, or alternatively configurable. In this case, when L is less than or equal to 4, the DCI includes one modulation and coding scheme (MCS) field, otherwise two MCS fields. Furthermore, the modulated symbols in the CWs that transmit the data can first be mapped across the layers associated with the CWs, then across frequency subcarriers, and finally across OFDM symbols.

[0356] The UE then decodes the DCI to determine the number of layers L, as well as other transmission parameters related to the data transmission (step 1402). After determining L, the UE decodes the data transmission with the variable length CRC (for error detection—step 1403). The UE also generates at least one channel quality indicator (CQI), and transmits the CQI via an uplink channel (step 1404). Using the example where the threshold is fixed at 4, the UE generates and transmits one CQI when L is less than or equal to 4, otherwise two CQIs.

[0357] Figure 15 A flowchart illustrating an example method 1500 in which a BS generates and transmits multi-layer data for UEs (labeled UE-k), in accordance with embodiments of the present disclosure, is shown. For example, method 1500 can be performed by BS 102.

[0358] ​​The method 1500 begins with a BS generating an L-layer data transmission, where the data transmission is composed of at least one code block (CB), and the CB includes a cyclic redundancy code (CRC) of length N. The length N of the CRC is a function of the length of the CB, and the length corresponds to a number of bits. Additionally, the BS generates downlink control information (DCI) associated with the data transmission (step 1501). The data transmission includes one codeword (CW) when L is less than or equal to a threshold, otherwise two CWs. For example, the threshold can be fixed at 4, or alternatively configurable. In this case, the DCI includes one modulation and coding scheme (MCS) field when L is less than or equal to 4, otherwise two MCS fields. Furthermore, modulation symbols in the CWs that transmit the data can first be mapped across layers associated with the CWs, then across frequency subcarriers, and then finally across OFDM symbols.

[0359] The BS then transmits the L-layer data with the DCI (step 1502). The BS also receives at least one channel quality indicator (CQI) and transmits the CQI via an uplink channel (step 1503). Using the example where the threshold is fixed at 4, the UE generates and transmits one CQI when L is less than or equal to 4, otherwise two CQIs.

[0360] Although Figure 14 and 15 show examples of methods for receiving configuration information and configuring a UE, respectively, various changes and modifications can be suggested or made to Figure 14 and 15 Each of the figures maybe repeated, occur in parallel, occur in a different order, occur multiple times, or not be performed in one or more embodiments, although shown as a series of steps.

[0361] Although the present disclosure has been described with an example embodiment, various changes and modifications can be suggested to one skilled in the art. It is intended that the present disclosure encompass such changes and modifications as fall within the scope of the appended claims.< / null> < / null> < / null> < / null> < / null>

Claims

1. A method performed by a user equipment (UE) in a wireless communication system, the method comprising: Cyclic redundancy code (CRC) is appended to each CB in at least one code block (CB) used for control information; Encode the at least one CB with an attached CRC; as well as Send uplink control information (UCI) including at least one encoded CB and an encoded CRC appended to said at least one CB. The length of the CRC appended to each CB depends on the size of the at least one CB, and Wherein, when the size of the at least one CB is within a first range, the length of the CRC attached to each CB is zero.

2. The method as described in claim 1, in, When the size of at least one CB is within a second range different from the first range, the length of the CRC appended to each CB is a first fixed value. Wherein, when the size of at least one CB falls within a third range different from the first and second ranges, the length of the CRC appended to each CB is a second fixed value different from the first fixed value, and The first fixed value and the second fixed value are positive integers.

3. The method of claim 1, further comprising: Append a CRC to the transport block (TB) used for data transmission; Encode the TB with CRC appended; as well as Send uplink data including the encoded TB and the encoded CRC appended to the TB.

4. A user equipment (UE) in a wireless communication system, the UE comprising: transceiver; as well as The controller, coupled to the transceiver, is configured to: Cyclic redundancy code (CRC) is appended to each CB in at least one code block (CB) used for control information; Encode the at least one CB with an attached CRC; as well as Send uplink control information (UCI) including at least one encoded CB and an encoded CRC appended to said at least one CB. The length of the CRC appended to each CB depends on the size of the at least one CB, and Wherein, when the size of the at least one CB is within a first range, the length of the CRC attached to each CB is zero.

5. The UE as described in claim 4, in, When the size of at least one CB is within a second range different from the first range, the length of the CRC appended to each CB is a first fixed value. Wherein, when the size of at least one CB falls within a third range different from the first and second ranges, the length of the CRC appended to each CB is a second fixed value different from the first fixed value, and The first fixed value and the second fixed value are positive integers.

6. The UE as claimed in claim 4, wherein, The controller is also configured to: Append a CRC to the transport block (TB) used for data transmission; Encode the TB with CRC appended; as well as Send uplink data including the encoded TB and the encoded CRC appended to the TB.

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