WO2021168777A1

WO2021168777A1 - Transport block size determination for multi-slot transmission

Info

Publication number: WO2021168777A1
Application number: PCT/CN2020/077132
Authority: WO
Inventors: Jing Dai; Chao Wei; Min Huang; Qiaoyu Li; Hao Xu; Chenxi HAO
Original assignee: Qualcomm Incorporated
Priority date: 2020-02-28
Filing date: 2020-02-28
Publication date: 2021-09-02

Abstract

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may determine information indicating an effective number of slots for a multi-slot communication; determine a transport block size (TBS) in accordance with the effective number of slots; and perform the multi-slot communication in accordance with the TBS. Numerous other aspects are provided.

Description

TRANSPORT BLOCK SIZE DETERMINATION FOR MULTI-SLOT TRANSMISSION

FIELD OF THE DISCLOSURE

Aspects of the present disclosure generally relate to wireless communication and to techniques and apparatuses for transport block size (TBS) determination for a multi-slot transmission.

BACKGROUND

Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, and/or the like) . Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency-division multiple access (FDMA) systems, orthogonal frequency-division multiple access (OFDMA) systems, single-carrier frequency-division multiple access (SC-FDMA) systems, time division synchronous code division multiple access (TD-SCDMA) systems, and Long Term Evolution (LTE) . LTE/LTE-Advanced is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the Third Generation Partnership Project (3GPP) .

A wireless communication network may include a number of base stations (BSs) that can support communication for a number of user equipment (UEs) . A user equipment (UE) may communicate with a base station (BS) via the downlink and uplink. The downlink (or forward link) refers to the communication link from the BS to the UE, and the uplink (or reverse link) refers to the communication link from the UE to the BS. As will be described in more detail herein, a BS may be referred to as a Node B, a gNB, an access point (AP) , a radio head, a transmit receive point (TRP) , a New Radio (NR) BS, a 5G Node B, and/or the like.

The above multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different user equipment to communicate on a municipal, national, regional, and even global level. New Radio (NR) , which may also be referred to as 5G, is a set of enhancements to the LTE mobile standard promulgated by the Third Generation Partnership Project (3GPP) . NR is designed to better support mobile broadband Internet access by improving spectral efficiency, lowering costs, improving services, making use of new spectrum, and better integrating with other open standards using orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) (CP-OFDM) on the downlink (DL) , using CP-OFDM and/or SC-FDM (e.g., also known as discrete Fourier transform spread OFDM (DFT-s-OFDM) ) on the uplink (UL) , as well as supporting beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation. However, as the demand for mobile broadband access continues to increase, there exists a need for further improvements in LTE and NR technologies. Preferably, these improvements should be applicable to other multiple access technologies and the telecommunication standards that employ these technologies.

SUMMARY

In some aspects, a method of wireless communication, performed by a user equipment (UE) , may include determining information indicating an effective number of slots for a multi-slot communication; determining a transport block size (TBS) in accordance with the effective number of slots; and performing the multi-slot communication in accordance with the TBS.

In some aspects, a UE for wireless communication may include a memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to determine information indicating an effective number of slots for a multi-slot communication; determine a TBS in accordance with the effective number of slots; and perform the multi-slot communication in accordance with the TBS.

In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a UE, may cause the one or more processors to determine information indicating an effective number of slots for a multi-slot communication; determine a TBS in accordance with the effective number of slots; and perform the multi-slot communication in accordance with the TBS.

In some aspects, an apparatus for wireless communication may include means for determining information indicating an effective number of slots for a multi-slot communication; means for determining a TBS in accordance with the effective number of slots; and means for performing the multi-slot communication in accordance with the TBS.

Aspects generally include a method, apparatus, system, computer program product, non-transitory computer-readable medium, user equipment, base station, wireless communication device, and/or processing system as substantially described herein with reference to and as illustrated by the drawings and specification.

The foregoing has outlined rather broadly the features and technical advantages of examples according to the disclosure in order that the detailed description that follows may be better understood. Additional features and advantages will be described hereinafter. The conception and specific examples disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. Characteristics of the concepts disclosed herein, both their organization and method of operation, together with associated advantages will be better understood from the following description when considered in connection with the accompanying figures. Each of the figures is provided for the purposes of illustration and description, and not as a definition of the limits of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the above-recited features of the present disclosure can be understood in detail, a more particular description, briefly summarized above, may be had by reference to aspects, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only certain typical aspects of this disclosure and are therefore not to be considered limiting of its scope, for the description may admit to other equally effective aspects. The same reference numbers in different drawings may identify the same or similar elements.

Fig. 1 is a block diagram conceptually illustrating an example of a wireless communication network, in accordance with various aspects of the present disclosure.

Fig. 2 is a block diagram conceptually illustrating an example of a base station in communication with a UE in a wireless communication network, in accordance with various aspects of the present disclosure.

Fig. 3 is a diagram illustrating an example of scheduling for a multi-slot communication, in accordance with various aspects of the present disclosure.

Fig. 4 is a diagram illustrating an example of TBS determination for a multi-slot communication, in accordance with various aspects of the present disclosure.

Fig. 5 is a diagram illustrating an example process performed, for example, by a user equipment, in accordance with various aspects of the present disclosure.

DETAILED DESCRIPTION

Various aspects of the disclosure are described more fully hereinafter with reference to the accompanying drawings. This disclosure may, however, be embodied in many different forms and should not be construed as limited to any specific structure or function presented throughout this disclosure. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Based on the teachings herein one skilled in the art should appreciate that the scope of the disclosure is intended to cover any aspect of the disclosure disclosed herein, whether implemented independently of or combined with any other aspect of the disclosure. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, the scope of the disclosure is intended to cover such an apparatus or method which is practiced using other structure, functionality, or structure and functionality in addition to or other than the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of a claim.

Several aspects of telecommunication systems will now be presented with reference to various apparatuses and techniques. These apparatuses and techniques will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, and/or the like (collectively referred to as “elements” ) . These elements may be implemented using hardware, software, or combinations thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.

It should be noted that while aspects may be described herein using terminology commonly associated with 3G and/or 4G wireless technologies, aspects of the present disclosure can be applied in other generation-based communication systems, such as 5G and later, including NR technologies.

Fig. 1 is a diagram illustrating a wireless network 100 in which aspects of the present disclosure may be practiced. The wireless network 100 may be an LTE network or some other wireless network, such as a 5G or NR network. The wireless network 100 may include a number of BSs 110 (shown as BS 110a, BS 110b, BS 110c, and BS 110d) and other network entities. A BS is an entity that communicates with user equipment (UEs) and may also be referred to as a base station, a NR BS, a Node B, a gNB, a 5G node B (NB) , an access point, a transmit receive point (TRP) , and/or the like. Each BS may provide communication coverage for a particular geographic area. In 3GPP, the term “cell” can refer to a coverage area of a BS and/or a BS subsystem serving this coverage area, depending on the context in which the term is used.

A BS may provide communication coverage for a macro cell, a pico cell, a femto cell, and/or another type of cell. A macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscription. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscription. A femto cell may cover a relatively small geographic area (e.g., a home) and may allow restricted access by UEs having association with the femto cell (e.g., UEs in a closed subscriber group (CSG) ) . A BS for a macro cell may be referred to as a macro BS. A BS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS. In the example shown in Fig. 1, a BS 110a may be a macro BS for a macro cell 102a, a BS 110b may be a pico BS for a pico cell 102b, and a BS 110c may be a femto BS for a femto cell 102c. A BS may support one or multiple (e.g., three) cells. The terms “eNB” , “base station” , “NR BS” , “gNB” , “TRP” , “AP” , “node B” , “5G NB” , and “cell” may be used interchangeably herein.

In some aspects, a cell may not necessarily be stationary, and the geographic area of the cell may move according to the location of a mobile BS. In some aspects, the BSs may be interconnected to one another and/or to one or more other BSs or network nodes (not shown) in the wireless network 100 through various types of backhaul interfaces such as a direct physical connection, a virtual network, and/or the like using any suitable transport network.

Wireless network 100 may also include relay stations. A relay station is an entity that can receive a transmission of data from an upstream station (e.g., a BS or a UE) and send a transmission of the data to a downstream station (e.g., a UE or a BS) . A relay station may also be a UE that can relay transmissions for other UEs. In the example shown in Fig. 1, a relay station 110d may communicate with macro BS 110a and a UE 120d in order to facilitate communication between BS 110a and UE 120d. A relay station may also be referred to as a relay BS, a relay base station, a relay, and/or the like.

Wireless network 100 may be a heterogeneous network that includes BSs of different types, e.g., macro BSs, pico BSs, femto BSs, relay BSs, and/or the like. These different types of BSs may have different transmit power levels, different coverage areas, and different impacts on interference in wireless network 100. For example, macro BSs may have a high transmit power level (e.g., 5 to 40 Watts) whereas pico BSs, femto BSs, and relay BSs may have lower transmit power levels (e.g., 0.1 to 2 Watts) .

A network controller 130 may couple to a set of BSs and may provide coordination and control for these BSs. Network controller 130 may communicate with the BSs via a backhaul. The BSs may also communicate with one another, e.g., directly or indirectly via a wireless or wireline backhaul.

UEs 120 (e.g., 120a, 120b, 120c) may be dispersed throughout wireless network 100, and each UE may be stationary or mobile. A UE may also be referred to as an access terminal, a terminal, a mobile station, a subscriber unit, a station, and/or the like. A UE may be a cellular phone (e.g., a smart phone) , a personal digital assistant (PDA) , a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet, a camera, a gaming device, a netbook, a smartbook, an ultrabook, a medical device or equipment, biometric sensors/devices, wearable devices (smart watches, smart clothing, smart glasses, smart wrist bands, smart jewelry (e.g., smart ring, smart bracelet) ) , an entertainment device (e.g., a music or video device, or a satellite radio) , a vehicular component or sensor, smart meters/sensors, industrial manufacturing equipment, a global positioning system device, or any other suitable device that is configured to communicate via a wireless or wired medium.

Some UEs may be considered machine-type communication (MTC) or evolved or enhanced machine-type communication (eMTC) UEs. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, and/or the like, that may communicate with a base station, another device (e.g., remote device) , or some other entity. A wireless node may provide, for example, connectivity for or to a network (e.g., a wide area network such as Internet or a cellular network) via a wired or wireless communication link. Some UEs may be considered Internet-of-Things (IoT) devices, and/or may be implemented as NB-IoT (narrowband internet of things) devices. Some UEs may be considered a Customer Premises Equipment (CPE) . UE 120 may be included inside a housing that houses components of UE 120, such as processor components, memory components, and/or the like. In some aspects, the processor components and the memory components may be coupled together. For example, the processor components (e.g., one or more processors) and the memory components (e.g., a memory) may be operatively coupled, communicatively coupled, electronically coupled, electrically coupled, and/or the like.

In general, any number of wireless networks may be deployed in a given geographic area. Each wireless network may support a particular radio access technology (RAT) and may operate on one or more frequencies. A RAT may also be referred to as a radio technology, an air interface, and/or the like. A frequency may also be referred to as a carrier, a frequency channel, and/or the like. Each frequency may support a single RAT in a given geographic area in order to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks may be deployed.

In some aspects, two or more UEs 120 (e.g., shown as UE 120a and UE 120e) may communicate directly using one or more sidelink channels (e.g., without using a base station 110 as an intermediary to communicate with one another) . For example, the UEs 120 may communicate using peer-to-peer (P2P) communications, device-to-device (D2D) communications, a vehicle-to-everything (V2X) protocol (e.g., which may include a vehicle-to-vehicle (V2V) protocol, a vehicle-to-infrastructure (V2I) protocol, and/or the like) , a mesh network, and/or the like. In this case, the UE 120 may perform scheduling operations, resource selection operations, and/or other operations described elsewhere herein as being performed by the base station 110.

As indicated above, Fig. 1 is provided as an example. Other examples may differ from what is described with regard to Fig. 1.

Fig. 2 shows a block diagram of a design 200 of base station 110 and UE 120, which may be one of the base stations and one of the UEs in Fig. 1. Base station 110 may be equipped with T antennas 234a through 234t, and UE 120 may be equipped with R antennas 252a through 252r, where in general T ≥ 1 and R ≥ 1.

At base station 110, a transmit processor 220 may receive data from a data source 212 for one or more UEs, select one or more modulation and coding schemes (MCS) for each UE based at least in part on channel quality indicators (CQIs) received from the UE, process (e.g., encode and modulate) the data for each UE based at least in part on the MCS (s) selected for the UE, and provide data symbols for all UEs. Transmit processor 220 may also process system information (e.g., for semi-static resource partitioning information (SRPI) and/or the like) and control information (e.g., CQI requests, grants, upper layer signaling, and/or the like) and provide overhead symbols and control symbols. Transmit processor 220 may also generate reference symbols for reference signals (e.g., the cell-specific reference signal (CRS) ) and synchronization signals (e.g., the primary synchronization signal (PSS) and secondary synchronization signal (SSS) ) . A transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, the overhead symbols, and/or the reference symbols, if applicable, and may provide T output symbol streams to T modulators (MODs) 232a through 232t. Each modulator 232 may process a respective output symbol stream (e.g., for OFDM and/or the like) to obtain an output sample stream. Each modulator 232 may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. T downlink signals from modulators 232a through 232t may be transmitted via T antennas 234a through 234t, respectively. According to various aspects described in more detail below, the synchronization signals can be generated with location encoding to convey additional information.

At UE 120, antennas 252a through 252r may receive the downlink signals from base station 110 and/or other base stations and may provide received signals to demodulators (DEMODs) 254a through 254r, respectively. Each demodulator 254 may condition (e.g., filter, amplify, downconvert, and digitize) a received signal to obtain input samples. Each demodulator 254 may further process the input samples (e.g., for OFDM and/or the like) to obtain received symbols. A MIMO detector 256 may obtain received symbols from all R demodulators 254a through 254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. A receive processor 258 may process (e.g., demodulate and decode) the detected symbols, provide decoded data for UE 120 to a data sink 260, and provide decoded control information and system information to a controller/processor 280. A channel processor may determine reference signal received power (RSRP) , received signal strength indicator (RSSI) , reference signal received quality (RSRQ) , channel quality indicator (CQI) , and/or the like. In some aspects, one or more components of UE 120 may be included in a housing.

On the uplink, at UE 120, a transmit processor 264 may receive and process data from a data source 262 and control information (e.g., for reports comprising RSRP, RSSI, RSRQ, CQI, and/or the like) from controller/processor 280. Transmit processor 264 may also generate reference symbols for one or more reference signals. The symbols from transmit processor 264 may be precoded by a TX MIMO processor 266 if applicable, further processed by modulators 254a through 254r (e.g., for DFT-s-OFDM, CP-OFDM, and/or the like) , and transmitted to base station 110. At base station 110, the uplink signals from UE 120 and other UEs may be received by antennas 234, processed by demodulators 232, detected by a MIMO detector 236 if applicable, and further processed by a receive processor 238 to obtain decoded data and control information sent by UE 120. Receive processor 238 may provide the decoded data to a data sink 239 and the decoded control information to controller/processor 240. Base station 110 may include communication unit 244 and communicate to network controller 130 via communication unit 244. Network controller 130 may include communication unit 294, controller/processor 290, and memory 292.

Controller/processor 240 of base station 110, controller/processor 280 of UE 120, and/or any other component (s) of Fig. 2 may perform one or more techniques associated with transport block size (TBS) determination for a multi-slot transmission, as described in more detail elsewhere herein. For example, controller/processor 240 of base station 110, controller/processor 280 of UE 120, and/or any other component (s) of Fig. 2 may perform or direct operations of, for example, process 500 of Fig. 5 and/or other processes as described herein.

Memories

242 and 282 may store data and program codes for base station 110 and UE 120, respectively. In some aspects, memory 242 and/or memory 282 may comprise a non-transitory computer-readable medium storing one or more instructions for wireless communication. For example, the one or more instructions, when executed (e.g., directly, or after compiling, converting, interpreting, and/or the like) by one or more processors of the base station 110 and/or the UE 120, may perform or direct operations of, for example, process 500 of Fig. 5 and/or other processes as described herein. In some aspects, executing instructions may include running the instructions, converting the instructions, compiling the instructions, interpreting the instructions, and/or the like. A scheduler 246 may schedule UEs for data transmission on the downlink and/or uplink.

In some aspects, UE 120 may include means for determining information indicating an effective number of slots for a multi-slot communication; means for determining a transport block size (TBS) in accordance with the effective number of slots; means for performing the multi-slot communication in accordance with the TBS; means for mapping encoded bits of the multi-slot communication to slots associated with the multi-slot communication in accordance with the effective number of slots; and/or the like. In some aspects, such means may include one or more components of UE 120 described in connection with Fig. 2, such as controller/processor 280, transmit processor 264, TX MIMO processor 266, MOD 254, antenna 252, DEMOD 254, MIMO detector 256, receive processor 258, and/or the like.

As indicated above, Fig. 2 is provided as an example. Other examples may differ from what is described with regard to Fig. 2.

Some radio access technologies (RATs) , such as 5G/NR, provide for repeated transmission of data (e.g., on a physical uplink shared channel (PUSCH) , a physical downlink shared channel (PDSCH) , or another form of data channel) over multiple slots. Such a repeated transmission may be referred to as a multi-slot transmission. A multi-slot transmission may be associated with improved reliability relative to a single-slot transmission of the same data. Thus, a multi-slot transmission with repetition may be useful in a coverage-limited scenario.

A multi-slot transmission may be scheduled by scheduling control information, such as scheduling DCI. A modulation and coding scheme (MCS) and resource allocation of a multi-slot transmission may be indicated in the scheduling DCI of the multi-slot transmission. The MCS and the resource allocation may be common over the multiple slots. The number of slots for a multi-slot transmission may be configured (e.g., 2 slots, 4 slots, 8 slots, and/or the like) , for example, using radio resource control (RRC) signaling. The configured number of slots may be used for initial transmission and retransmission. The number of slots may be semi-static, except for in a time division duplexing (TDD) system with dynamic slot format. In a TDD system with dynamic slot format, if at least one symbol collides with a multi-slot communication in a given slot, then the multi-slot communication in the given slot would be dropped.

For each slot of the multi-slot communication, the transmission block (TB) may be the same, but the encoded bits can differ. For example, the redundancy version (RV) of each slot can be different. The RV of the first slot of a multi-slot communication may be indicated in the scheduling DCI, and the RV of the nth slot may be determined by ‘n mod 4’ . For example, for an initial transmission of a 4-slot PUSCH/PDSCH, the RV arrangement may be {RV0, RV2, RV3, RV1} . For a retransmission of a 4-slot PUSCH/PDSCH, the RV arrangement may be {RV3, RV1, RV0, RV2} .

For an uplink coverage-limited scenario, a longer transmission time may improve transmission reliability due to limited transmit power of the UE. For example, for the same TB size (TBS) and MCS (and thus the same total number of resource elements (REs) needed for a transmission) , a resource allocation (RA) can be wider in the frequency domain or longer in the time domain. For the downlink, where transmit power from the BS is generally not a limitation, a wider frequency RA and a longer RA can have similar performance. However, for uplink transmissions in uplink coverage-limited scenarios, where UE may have already been transmitting at the UE’s maximum transmit power, the longer RA may provide better performance than the wider- frequency RA due to a higher transmit energy (and thus a higher per-information-bit energy) . In other words, a narrower bandwidth may have lower noise power, which leads to a higher signal to noise ratio (SNR) . For the downlink, a lower coding rate generally leads to better performance, while for the uplink, there may be a tradeoff between the coding gain and the SNR loss –both of which are associated with a lower coding rate.

A coding gain, measured in decibels (dB) , indicates a reduction to input power that can be achieved by an error correction code while maintaining a constant error rate. Coding gain may be affected by incremental redundancy (IR) combining gain, code block (CB) size, and other factors.

A coding rate (also referred to as a code rate) is a ratio of an achieved data rate and a maximum or ideal data rate. For example, an indicated coding rate (R) may be indicated by the MCS index in DCI, and may also be referred to as a target coding rate (e.g., for a single-slot communication) . An effective coding rate (R _eff) may indicate a ratio of the number of information bits in a PUSCH to the total number of encoded bits in the PUSCH. For example, for a single-slot communication, R _eff=R (or approaches R, due to some small impact of rate matching) , and for a multi-slot communication, R _eff=R/M (or approaches) , where M is the number of slots in the multi-slot communication. A nominal coding rate R _nom is a coding rate used for incremental redundancy (IR) by parity checking bits of the code. Repeated bits are not counted for the calculation of R _nom. Since repeated slots are associated with different RVs, for higher R _eff values, R _nom=R _eff (assuming no overlapping of different RVs for a multi-slot communication) . However, for small R _eff (e.g. R _eff＜R _nom, min) , it may be impossible for R _nom to be lower than the lowest coding rate R _nom, min supported by the channel code. In this case, encoded bits are circularly repeated, and R _nom is truncated by R _nom, min. An IR combining gain may be determined by R _nom, and a lower R _nom corresponds to a higher IR combining gain. R _nom, min may identify a minimum coding rate associated with a base graph used for error correction coding (e.g., low density parity check (LDPC) coding) .

An MCS table may indicate an MCS index (I _MCS) that maps to a combination of a modulation order (Qm) and a coding rate (R) . The multi-slot communication is generally applied to uplink coverage-limited scenarios, where a lower MCS index associated with a lower modulation order (Q _m) and a lower coding rate are indicated. For example, an I _MCS of 2 in an MCS table may correspond to Q _m = 2 (for quadrature phase shift keying (QPSK) ) and R = 0.19. Generally, the combination of Q _m and R values in the MCS table is low-with-low or high-with-high, because the low-with-high combination is unreasonable for a single-slot case. Furthermore, in the MCS table, the highest R value associated with a Q _m of 2 is 0.66. However, the indicated coding rate R is the target coding rate of a single-slot transmission, and for M-slot transmissions (M = 2, 4 or 8) , R _eff=R/M can be low, which leads to a larger bandwidth with higher noise power, and can cause a lower SNR for UL. This may be particularly damaging in uplink coverage-limited scenarios, thereby diminishing UE coverage and reducing throughput of the network. For example, when R _nom approaches R _nom, min=1/5, there may be no additional IR combining gain with the decrease of R _eff. Furthermore, even with QPSK and R = 0.66, M = 8 can result in an R _effof 0.083 (lower than the supported R _nom, min=1/5) .

Some techniques and apparatuses described herein provide determination of a TBS for a multi-slot communication. For example, a UE or a base station may determine a TBS based at least in part on an effective number of slots for a multi-slot communication. The effective number of slots may indicate a number of slots over which encoded bits of a multi-slot communication are actually encoded (e.g., in comparison to an original number of slots, which may be a configured or semi-static slot configuration of the multi-slot communication) . The UE or the base station may determine the TBS based at least in part on scaling a number of REs allocated to a PUSCH/PDSCH or by scaling a target coding rate associated with determining the TBS. Furthermore, the original number of slots may be semi-statically configured and/or dynamically indicated (e.g., jointly with one or more other values) .

In this way, coding gain may be improved and coverage may be improved, particularly for cell edge UEs. For example, for a cell edge UE with a target uplink throughput of 100 kbps (with 30 kHz subcarrier spacing, which has 0.5 ms per slot) , a UE can use a single-slot PUSCH or a multi-slot PUSCH. For the single-slot PUSCH, an average TBS of each PUSCH may be 50 bits (not considering a potential retransmission) . For the multi-slot PUSCH, an average TBS may be 4 *50 bits = 200 bits. In this case, the bandwidth may also be 4 times larger than the single-slot PUSCH under the same MCS indicated. The larger TBS may be associated with larger code block size (CBS) , and has higher coding gain than the single-slot PUSCH. For example, in some situations, a 200 bit CBS has approximately 1.1 dB coding gain over a CBS of 50 bits. Furthermore, if techniques and apparatuses described herein are not used to determine the TBS size for the multi-slot PUSCH, the bandwidth of the multi-slot PUSCH (with a constant MCS) can be 4 times larger, potentially leading to an SNR loss of 10*log ₁₀ (4) = 6.0 dB for the transmit power-limited uplink scenario.

Fig. 3 is a diagram illustrating an example 300 of scheduling for a multi-slot communication, in accordance with various aspects of the present disclosure. The operations described in connection with example 300 may be performed by a UE. Fig. 3 shows downlink (DL) communications (e.g., to the UE from a base station) and uplink (UL) communications (e.g., from the UE to the base station) .

As shown in Fig. 3, and by reference number 310, the UE may receive a physical downlink control channel (PDCCH) . For example, the PDCCH may carry DCI scheduling a multi-slot communication (e.g., the 4-slot PUSCH shown by reference number 320) . The DCI may indicate an MCS and a resource allocation for the multi-slot communication. The number of slots of the multi-slot communication may be referred to as an original number of slots, and may be represented by M. M may be RRC configured. If the 4-slot PUSCH is on a TDD system with dynamic slot format, and at least one DL symbol collides with the PUSCH in a given slot, then the PUSCH in the given slot may be dropped.

As indicated above, Fig. 3 is provided as an example. Other examples may differ from what is described with respect to Fig. 3.

Fig. 4 is a diagram illustrating an example 400 of TBS determination for a multi-slot communication, in accordance with various aspects of the present disclosure. As shown, Fig. 4 includes a UE 120 and a BS 110.

As shown by reference number 410, the UE 120 may receive, from the BS 110, DCI scheduling a multi-slot communication. As shown, the DCI indicates an original number of slots M. In some aspects, the DCI may indicate an effective number of slots M’ for the multi-slot communication. M’ may be no larger than M. Encoded bits of the multi-slot communication may be mapped over the M’s lots. For example, a slot may be included in the original number of slots and not the effective number of slots based at least in part on a slot format indicator of a slot or a collision between the multi-slot communication and another communication in the slot.

In some aspects, M may be semi-statically configured and/or dynamically indicated. For dynamic indication, M may be jointly indicated in a time-domain resource allocation (TDRA) field of the DCI 410. For example, M may be jointly indicated with at least one of a mapping type, a slot offset, a start and length indictor (SLIV) , and/or the like. In some aspects, M may be indicated based at least in part on a pre-configured TDRA table.

As shown by reference number 420, the UE 120 may determine M’. In some aspects, the UE 120 may receive information identifying M’ from the BS 110 (e.g., in the DCI shown by reference number 410) . This may be referred to as explicit indication of M’. In some aspects, the UE 120 may determine M’ based at least in part on M and based at least in part on a slot format indicator (SFI) associated with slots of the multi-slot communication. For example, the SFI may be indicated in DCI (e.g., the DCI shown by reference number 410 or another DCI) . In this case, if no collision is detected due to a TDD slot format based at least in part on the DCI 410, then M’= M. If the multi-slot communication collides with one or more other communications in K slots (where K is less than M) , then M’= M –K.

As shown by reference number 430, the UE 120 may determine a TBS based at least in part on M’. In some aspects, the UE 120 may modify (e.g., scale) the total number of REs allocated to the multi-slot communication based at least in part on M’. The total number of REs allocated to the multi-slot communication may be represented by N _RE. In this case, N _RE=N′ _RE·n _PRB·M′, where N′ _RE is the number of REs allocated for the multi-slot communication per PRB and per slot, and n _PRB is the number of PRBs allocated to the multi-slot communication. In some aspects, the UE 120 may modify (e.g., scale) a target coding rate (e.g., R) associated with the multi-slot communication based at least in part on M’. For example, an intermediate number of information bits N _info is determined by N _info=N _RE·R·M′·W _m·v, where R and Q _m are the indicated coding rate and modulation order, respectively, and v is the number of transmission layers of the multi-slot communication. The TBS is determined based at least in part on N _info and may be adjusted based at least in part on rules related to LDPC coding and cyclic redundancy check (CRC) bits attachment. As an example, for TBS determination based on N _info e.g. for N _info＞3824, it is firstly quantized to

where

then for e.g. N′ _info≤8424 and target coding rate R 1/4, TBS is quantized as

As shown by reference number 440, the UE 120 may encode the communication. For example, the UE 120 may encode bits of the PUSCH or PDSCH for mapping over the M’ slots of the multi-slot communication. As shown by reference number 450, the UE 120 may map the encoded bits over the M’ slots of the multi-slot communication. In other words, the UE 120 may perform RE mapping. For example, the UE may perform RE mapping in sequential order of the M’ slots. The mapping of slots may be performed after the mapping of transmission layers (e.g., in the spatial domain) and subcarriers (e.g., in the frequency domain) . As shown by reference number 460, the UE 120 and the BS 110 may perform the multi-slot communication in accordance with the mapping of the encoded bits. For example, the UE 120 may transmit a multi-slot PUSCH in accordance with the mapping or may receive a multi-slot PDSCH in accordance with the mapping. Thus, the UE 120 may determine the TBS based at least in part on M’, which improves SNR and coding gain relative to determining the TBS without regard to the effective number of slots of a multi-slot communication.

It should be noted that the techniques described herein can be applied for forms of communication other than uplink or downlink communications, such as sidelink communications, device-to-device communications, and/or the like.

As indicated above, Fig. 4 is provided as an example. Other examples may differ from what is described with respect to Fig. 4.

Fig. 5 is a diagram illustrating an example process 500 performed, for example, by a UE, in accordance with various aspects of the present disclosure. Example process 500 is an example where the UE (e.g., UE 120 and/or the like) performs operations associated with transport block size (TBS) determination for a multi-slot transmission. In some aspects, the operations of process 500 may be performed by a scheduled entity, such as a UE. In some aspects, the operations of process 500 may be performed by a scheduling entity, such as a BS. In other words, a scheduling entity and/or a scheduled entity may determine a TBS using the techniques described herein.

As shown in Fig. 5, in some aspects, process 500 may include determining information indicating an effective number of slots for a multi-slot communication (block 510) . For example, the UE (e.g., using antenna 252, DEMOD 254, MIMO detector 256, receive processor 258, controller/processor 280, and/or the like) may determine information indicating an effective number of slots for a multi-slot communication (e.g., M’) , as described above.

As further shown in Fig. 5, in some aspects, process 500 may include determining a TBS in accordance with the effective number of slots (block 520) . For example, the UE (e.g., using controller/processor 280 and/or the like) may determine a TBS in accordance with the effective number of slots, as described above.

As further shown in Fig. 5, in some aspects, process 500 may include performing the multi-slot communication in accordance with the TBS (block 530) . For example, the UE (e.g., using antenna 252, DEMOD 254, MIMO detector 256, receive processor 258, controller/processor 280, transmit processor 264, TX MIMO processor 266, MOD 254, antenna 252, and/or the like) may perform the multi-slot communication in accordance with the TBS, as described above.

Process 500 may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein.

In a first aspect, determining the information indicating the effective number of slots is based at least in part on receiving information identifying the effective number of slots in scheduling control information of the multi-slot communication.

In a second aspect, alone or in combination with the first aspect, determining the information indicating the effective number of slots is based at least in part on an original number of slots associated with the multi-slot communication and a slot format indicator of slots associated with the multi-slot communication.

In a third aspect, alone or in combination with one or more of the first and second aspects, the original number of slots is dynamically indicated in scheduling control information of the multi-slot communication, and the original number of slots is jointly indicated with at least one of a mapping type, a slot offset, or a start and length indicator value of the scheduling control information.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the original number of slots is semi-statically configured for the UE.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, process 500 includes mapping encoded bits of the multi-slot communication to slots associated with the multi-slot communication in accordance with the effective number of slots.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, mapping the encoded bits to the slots is performed after mapping of transmission layers and subcarriers of the multi-slot communication.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, determining the TBS further comprises modifying a total number of resource elements (REs) allocated to the multi-slot communication based at least in part on the effective number of slots.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, the total number of REs is determined based at least in part on combining a number of REs allocated to the multi-slot communication per slot and a number of physical resource blocks (PRBs) allocated to the multi-slot communication.

In a ninth aspect, alone or in combination with one or more of the first through sixth aspects, determining the TBS is based at least in part on scaling a target coding rate based at least in part on the effective number of slots.

In a tenth aspect, alone or in combination with one or more of the first through sixth and ninth aspects, the scaled target coding rate is used to determine an intermediate number of information bits from which the TBS is determined.

Although Fig. 5 shows example blocks of process 500, in some aspects, process 500 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in Fig. 5. Additionally, or alternatively, two or more of the blocks of process 500 may be performed in parallel.

The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the aspects to the precise form disclosed. Modifications and variations may be made in light of the above disclosure or may be acquired from practice of the aspects.

As used herein, the term “component” is intended to be broadly construed as hardware, firmware, and/or a combination of hardware and software. As used herein, a processor is implemented in hardware, firmware, and/or a combination of hardware and software.

As used herein, satisfying a threshold may, depending on the context, refer to a value being greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, not equal to the threshold, and/or the like.

It will be apparent that systems and/or methods described herein may be implemented in different forms of hardware, firmware, and/or a combination of hardware and software. The actual specialized control hardware or software code used to implement these systems and/or methods is not limiting of the aspects. Thus, the operation and behavior of the systems and/or methods were described herein without reference to specific software code-it being understood that software and hardware can be designed to implement the systems and/or methods based, at least in part, on the description herein.

Even though particular combinations of features are recited in the claims and/or disclosed in the specification, these combinations are not intended to limit the disclosure of various aspects. In fact, many of these features may be combined in ways not specifically recited in the claims and/or disclosed in the specification. Although each dependent claim listed below may directly depend on only one claim, the disclosure of various aspects includes each dependent claim in combination with every other claim in the claim set. A phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combination with multiples of the same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c) .

No element, act, or instruction used herein should be construed as critical or essential unless explicitly described as such. Also, as used herein, the articles “a” and “an” are intended to include one or more items, and may be used interchangeably with “one or more. ” Furthermore, as used herein, the terms “set” and “group” are intended to include one or more items (e.g., related items, unrelated items, a combination of related and unrelated items, and/or the like) , and may be used interchangeably with “one or more. ” Where only one item is intended, the phrase “only one” or similar language is used. Also, as used herein, the terms “has, ” “have, ” “having, ” and/or the like are intended to be open-ended terms. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise.

Claims

A method of wireless communication performed by a user equipment (UE) , comprising:

determining information indicating an effective number of slots for a multi-slot communication;

determining a transport block size (TBS) in accordance with the effective number of slots; and

performing the multi-slot communication in accordance with the TBS.
The method of claim 1, wherein determining the information indicating the effective number of slots is based at least in part on receiving information identifying the effective number of slots in scheduling control information of the multi-slot communication.
The method of one or more of the previous claims, wherein determining the information indicating the effective number of slots is based at least in part on an original number of slots associated with the multi-slot communication and a slot format indicator of slots associated with the multi-slot communication.
The method of claim 3, wherein the original number of slots is dynamically indicated in scheduling control information of the multi-slot communication, and wherein the original number of slots is jointly indicated with at least one of a mapping type, a slot offset, or a start and length indicator value of the scheduling control information.
The method of claim 3, wherein the original number of slots is semi-statically configured for the UE.
The method of one or more of the previous claims, further comprising:

mapping encoded bits of the multi-slot communication to slots associated with the multi-slot communication in accordance with the effective number of slots.
The method of claim 6, wherein mapping the encoded bits to the slots is performed after mapping of transmission layers and subcarriers of the multi-slot communication.
The method of one or more of the previous claims, wherein determining the TBS further comprises modifying a total number of resource elements (REs) allocated to the multi-slot communication based at least in part on the effective number of slots.
The method of claim 8, wherein the total number of REs is determined based at least in part on combining a number of REs allocated to the multi-slot communication per slot and a number of physical resource blocks (PRBs) allocated to the multi-slot communication.
The method of one or more of claims 1-7, wherein determining the TBS is based at least in part on scaling a target coding rate based at least in part on the effective number of slots.
The method of claim 10, wherein the scaled target coding rate is used to determine an intermediate number of information bits from which the TBS is determined.
A user equipment (UE) for wireless communication, comprising:

a memory; and

one or more processors operatively coupled to the memory, the memory and the one or more processors configured to:

determine information indicating an effective number of slots for a multi-slot communication;

determine a transport block size (TBS) in accordance with the effective number of slots; and

perform the multi-slot communication in accordance with the TBS.
A non-transitory computer-readable medium storing one or more instructions for wireless communication, the one or more instructions comprising:

one or more instructions that, when executed by one or more processors of a user equipment (UE) , cause the one or more processors to:

determine information indicating an effective number of slots for a multi-slot communication;

determine a transport block size (TBS) in accordance with the effective number of slots; and

perform the multi-slot communication in accordance with the TBS.
An apparatus for wireless communication, comprising:

means for determining information indicating an effective number of slots for a multi-slot communication;

means for determining a transport block size (TBS) in accordance with the effective number of slots; and

means for performing the multi-slot communication in accordance with the TBS.