Transport Block Size Determination for Sidelink Communication

Abstract

Methods, systems, and devices for sidelink wireless communication are described, where a transmitting device may determine a transport block size (TBS) for sidelink data channel transmission and provide an indication in sidelink control information (SCI) to allow a receiving device to determine the TBS to be used for decoding the sidelink communication. The indication provided in the SCI may be an explicit indication in an information element indicating whether a feedback channel resource is included or excluded when determining the number of symbols used for TBS determination. The indication provided in the SCI may also be an implicit indication based on one or more values of one or more parameters provided in the SCI. Sidelink communication devices may determine the same TBS across multiple instances of sidelink data channel transmission that may be transmitted using time slots having different slot formats.

Description

[0001] Cross-reference

[0002] This patent application claims priority to U.S. Patent Application No. 17 / 165,140, titled "TRANSPORT BLOCK SIZE DETERMINATION FOR SIDELNK COMMINICATIONS," filed on Feb. 2, 2021, by WU et al., which claims the benefit of U.S. Provisional Patent Application No. 62 / 975,698, titled "TRANSPORT BLOCK SIZE DETERMINATION FOR SIDELNK COMMINICATIONS," filed on Feb. 12, 2020, by WU et al., and these applications are assigned to the assignee of the present application. Technical Field

[0003] The following generally relates to wireless communications and, more particularly, to transport block size determination for sidelink communications.

[0004] Background

[0005] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, broadcasting, and so on. These systems may be capable of supporting communication with multiple users by sharing available system resources, such as time, frequency, and power. Examples of such multi-access systems include fourth-generation (4G) systems, such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth-generation (5G) systems, which may be referred to as New Radio (NR) systems. These systems may employ various techniques, such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), or Discrete Fourier Transform Spread Orthogonal Frequency Division Multiplexing (DFT-S-OFDM). A wireless multi-access communication system may include one or more base stations or one or more network access nodes, each of which simultaneously supports communication for multiple communication devices, which may also be referred to as user equipment (UE).

[0006] Some wireless communication systems can support both an access link and a sidelink. The access link is the communication link between a UE and a base station. In some examples, the access link may be referred to as the Uu interface. Specifically, the Uu interface may refer to the air interface for downlink transmission, uplink transmission, or both. The sidelink is the communication link between similar devices. For example, the sidelink may support communication between multiple UEs (e.g., in a vehicle-to-everything (V2X) system, vehicle-to-vehicle (V2V) system, device-to-device (D2D) system, etc.). In some examples, the sidelink may support unicast messaging, groupcast messaging, multicast messaging, broadcast messaging, or a combination thereof. In some cases, repetition of sidelink communication may be used to increase the likelihood of successfully receiving a sidelink message at a receiving device. In such systems, efficient and reliable techniques for receiving and decoding sidelink communication may be desirable.

[0007] Overview

[0008] The described techniques relate to improved methods, systems, devices, or apparatuses for supporting transport block size (TBS) determination for sidelink communication. Aspects of the present disclosure provide a communication device (which may be a base station (e.g., an evolved Node B (eNB), a next-generation Node B, or a Gigabit Node B (any of which may be referred to as a gNB)) or a user equipment (UE)) in a wireless communication system (e.g., a vehicle-to-everything (V2X) system, a vehicle-to-vehicle (V2V) network, a cellular V2X (C-V2X) network, a device-to-device (D2D) system, etc.) to determine a TBS for encoding and decoding sidelink communication. In some cases, a transmitting device may determine a TBS for sidelink communication (e.g., sidelink data channel transmission) and provide sidelink control information (SCI) to a receiving device indicating how to determine the TBS for decoding the sidelink communication. The receiving device may receive the SCI and use the TBS determined based on the indication provided in the SCI to decode the sidelink communication.

[0009] In some cases, the indication provided in the SCI can be an explicit indication (e.g., a dedicated parameter carried in the SCI) indicating whether the sidelink feedback resource (e.g., physical sidelink feedback channel (PSFCH) resource) is included or excluded when determining the number of symbols for TBS determination. In other cases, the indication provided in the SCI can be an implicit indication based on one or more values of one or more parameters provided in the SCI (e.g., one or more of modulation and coding scheme (MCS) index, code rate, modulation order, channel data priority, or transmission type, etc.). In some cases, the sidelink communication may include an initial sidelink data channel transmission and one or more repetitions of the sidelink data channel transmission, which may be transmitted using time slots with different time slot formats (e.g., in a time slot including a PSFCH resource and in a time slot not including a PSFCH resource), where the determined TBS for different time slot formats may be consistent, and thus allowing efficient decoding of multiple transmissions (e.g., through combining techniques at the receiving device). As a result, a device operating according to such techniques may include features for improving communication reliability and efficiency, and in some examples, may enhance the enhanced efficiency for high-reliability and low-latency operations, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 An example of a system for wireless communication supporting transport block size determination for sidelink communication in accordance with aspects of the present disclosure is illustrated.

[0012] Figure 2 An example of a wireless communication system supporting transport block size determination for sidelink communication in accordance with aspects of the present disclosure is illustrated.

[0013] Figure 3 An example of a sidelink time slot format supporting transport block size determination for sidelink communication in accordance with aspects of the present disclosure is illustrated.

[0014] Figure 4 An example of a process flow supporting transport block size determination for sidelink communication in accordance with aspects of the present disclosure is illustrated.

[0015] Figure 5 and 6 A block diagram of a device supporting transport block size determination for sidelink communication in accordance with aspects of the present disclosure is shown.

[0016] Figure 7 A block diagram of a communication manager supporting transport block size determination for sidelink communication in accordance with aspects of the present disclosure is shown.

[0017] Figure 8FIG. shows a diagram of a system including a device supporting transport block size determination for sidelink communication in accordance with aspects of the present disclosure.

[0018] Figures 9 to 12 FIG. shows a flow chart illustrating a method supporting transport block size determination for sidelink communication in accordance with aspects of the present disclosure.

[0019] DETAILED DESCRIPTION

[0020] A wireless communication system may support both an access link and a sidelink for communication between one or more communication devices. The access link may refer to a communication link between a user equipment (UE) and a base station. For example, the access link may support uplink signaling, downlink signaling, connection procedures, etc. The sidelink may refer to any communication link between similar wireless devices (e.g., a communication link between UEs, or a backhaul communication link between base stations). It should be noted that although the various examples provided herein are discussed in terms of UE sidelink devices, such sidelink technologies may be used for any type of wireless device that uses sidelink communication. For example, the sidelink may support one or more of the following: device-to-device (D2D) communication, vehicle-to-everything (V2X) and / or vehicle-to-vehicle (V2V) communication, message relaying, discovery signaling, beacon signaling, or other signals transmitted from one UE to one or more other UEs over the air.

[0021] In some examples, sidelink communication may support feedback transmission. For example, in sidelink multicast or broadcast communication, one or more UEs may convey hybrid automatic repeat request (HARQ) feedback to improve performance with the group. In sidelink unicast communication, a data receiving UE may transmit HARQ feedback so that the data transmitting UE knows whether the packet has been successfully delivered. The HARQ feedback may include an acknowledgement or a negative acknowledgement or both for sidelink communication. The feedback may be provided in a sidelink feedback resource (such as a physical sidelink feedback channel (PSFCH) resource that may be configured in certain time slots (e.g., every 1, 2, or 4 time slots)). When a time slot is configured with a PSFCH resource, the orthogonal frequency division multiplexing (OFDM) symbols configured for PSFCH transmission will not be available for data channel (physical sidelink shared channel (PSSCH)) transmission. For example, in a new radio sidelink, the feedback resource and associated gap may occupy the last four OFDM symbols in a time slot with a PSFCH resource.

[0022] Further, in some cases, to enhance reliability, the transmitting UE may transmit multiple repetitions of the sidelink data channel transmission. For example, a UE communicating low latency and high reliability data may perform an initial sidelink data channel transmission followed by one or more repetitions of the sidelink data channel transmission. When encoding the sidelink data channel transmission, the transmitting UE may determine the TBS based on the time slot format of the time slot to carry the transmission by determining the number of OFDM symbols available for shared channel transmission and then determining the TBS based on the number of OFDM symbols and the MCS of the transmission. However, in cases where different instances of the sidelink data channel transmission use time slots with different time slot formats, determining the TBS for each time slot individually may result in different TBSs for different examples of the sidelink data channel transmission, which may prevent efficient decoding of the sidelink data channel transmission, such as in cases where the receiving UE attempts to combine multiple instances of the transmission.

[0023] In various aspects, the techniques discussed herein allow the transmitting UE and the receiving UE to identify the TBS for transmission and allow for efficient encoding and decoding of the transmission. In some cases, the transmitting UE may determine the TBS for the sidelink data channel transmission and provide an indication in the SCI to allow the receiving UE to unambiguously determine the TBS to be used for decoding the sidelink communication. In some cases, the indication provided in the SCI may be an explicit indication (e.g., a dedicated parameter of the SCI) indicating whether the PSFCH resource is included or excluded when determining the number of symbols for TBS determination. In other cases, the indication provided in the SCI may be an implicit indication based on one or more values of one or more parameters provided in the SCI (e.g., one or more of the MCS index, code rate, modulation order, channel data priority, or transmission type, etc.). In such cases, the transmitting UE and the receiving UE may determine the same TBS across multiple instances of the sidelink data channel transmission that may be transmitted using time slots with different time slot formats. Thus, using the same TBS for different time slot formats may allow for efficient decoding or combination of multiple transmissions at the receiving UE.

[0024] Certain aspects of the subject matter described in this disclosure can achieve one or more of the following potential advantages. The techniques employed by the described UE can provide benefits and enhancements to the operation of the UE. For example, the operations performed by the UE can provide improvements in the reliability and efficiency in wireless operations. In some examples, the UE can support high reliability by enabling efficient decoding of one or more instances of sidelink data channel transmissions based on an unambiguous TBS at the transmitting and receiving devices. The described techniques can thus include features for improving communication reliability, enhanced coding and decoding efficiency, reduced power consumption (e.g., through reduced HARQ-based retransmissions), and in some examples, enhanced efficiency for high-reliability and low-latency operations, etc.

[0025] Aspects of the present disclosure are initially described in the context of a wireless communication system. Subsequently, aspects of the present disclosure are illustrated and described by and with reference to sidelink slot formats and procedure flows related to TBS determination in sidelink communication. Aspects of the present disclosure are further illustrated and described by and with reference to apparatus diagrams, system diagrams, and flowcharts related to TBS determination for sidelink communication.

[0026] Figure 1 An example of a wireless communication system 100 supporting TBS determination for sidelink communication in accordance with aspects of the present disclosure is illustrated. The wireless communication system 100 can include one or more base stations 105, one or more UEs 115, and a core network 130. In some examples, the wireless communication system 100 can be a Long Term Evolution (LTE) network, an Advanced LTE (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network. In some examples, the wireless communication system 100 can support enhanced broadband communication, ultra-reliable (e.g., mission-critical) communication, low-latency communication, communication with low-cost and low-complexity devices, or any combination thereof.

[0027] The base stations 105 can be dispersed over a geographic area to form the wireless communication system 100, and can be devices of different forms or with different capabilities. The base stations 105 and the UEs 115 can communicate wirelessly via one or more communication links 125. Each base station 105 can provide a coverage area 110, and the UEs 115 and the base stations 105 can establish one or more communication links 125 over the coverage area 110. The coverage area 110 can be an example of a geographic area over which the base stations 105 and the UEs 115 can support signal communication according to one or more radio access technologies.

[0028] Each UE 115 may be dispersed throughout the coverage area 110 of the wireless communication system 100, and each UE 115 may be stationary or mobile, or stationary and mobile at different times. Each UE 115 may be a device of different forms or with different capabilities. In Figure 1 Some example UEs 115 are illustrated. The UEs 115 described herein may be capable of communicating with various types of devices, such as other UEs 115, base stations 105, or network equipment (e.g., core network nodes, relay devices, integrated access and backhaul (IAB) nodes, or other network equipment), as Figure 1 shown.

[0029] Each base station 105 may communicate with the core network 130, or with each other, or both. For example, the base station 105 may interface with the core network 130 via one or more backhaul links 120 (e.g., via S1, N2, N3, or other interfaces). The base stations 105 may communicate with each other directly (e.g., directly between the base stations 105), or indirectly (e.g., via the core network 130), or directly and indirectly over the backhaul links 120 (e.g., via X2, Xn, or other interfaces). In some examples, the backhaul link 120 may be or include one or more wireless links.

[0030] One or more of the base stations 105 described herein may include or may be referred to by those of ordinary skill in the art as a base transceiver station, radio base station, access point, radio transceiver, B node, evolved B node (eNB), next-generation B node, or gigabit B node (any of which may be referred to as a gNB), home B node, home evolved B node, or other suitable terms.

[0031] The UE 115 may include or may be referred to as a mobile device, wireless device, remote device, handheld device, or subscriber device, or some other suitable term, where "device" may also be referred to as a unit, station, terminal, or client, etc. The UE 115 may also include or may be referred to as a personal electronic device, such as a cellular phone, personal digital assistant (PDA), tablet computer, laptop computer, or personal computer. In some examples, the UE 115 may include or be referred to as a wireless local loop (WLL) station, Internet of Things (IoT) device, Internet of Everything (IoE) device, or machine type communication (MTC) device, etc., which may be implemented in various objects such as appliances or vehicles, meters, etc.

[0032] The UEs 115 described herein may be capable of communicating with various types of devices, such as other UEs 115 that may sometimes act as relays, as well as base stations 105 and network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, relay base stations, etc., as Figure 1 shown.

[0033] UE 115 and base station 105 may communicate wirelessly with each other via one or more communication links 125 over one or more carriers. The term "carrier" may refer to a set of radio frequency spectrum resources having a defined physical layer structure for supporting communication link 125. For example, a carrier for communication link 125 may include a portion (e.g., bandwidth part (BWP)) of a radio frequency spectrum band that operates according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information), control signaling for coordinating carrier operation, user data, or other signaling. The wireless communication system 100 may support communicating with UE 115 using carrier aggregation or multi-carrier operation. UE 115 may be configured to have multiple downlink component carriers and one or more uplink component carriers according to a carrier aggregation configuration. Carrier aggregation may be used in conjunction with both frequency division duplex (FDD) and time division duplex (TDD) component carriers.

[0034] The communication link 125 shown in the wireless communication system 100 may include an uplink transmission from UE 115 to base station 105, or a downlink transmission from base station 105 to UE 115. A carrier may carry downlink or uplink communication (e.g., in FDD mode), or may be configured to carry both downlink communication and uplink communication (e.g., in TDD mode).

[0035] A carrier may be associated with a specific bandwidth of the radio frequency spectrum, and in some examples, the carrier bandwidth may be referred to as the "system bandwidth" of the carrier or the wireless communication system 100. For example, the carrier bandwidth may be one of several determined bandwidths (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 megahertz (MHz)) of a carrier for a particular radio access technology. Devices of the wireless communication system 100 (e.g., base station 105, UE 115, or both) may have a hardware configuration that supports communication over a specific carrier bandwidth, or may be configurable to support communication over one of a set of carrier bandwidths. In some examples, the wireless communication system 100 may include a base station 105 or UE 115 that supports simultaneous communication via carriers associated with multiple carrier bandwidths. In some examples, each served UE 115 may be configured to operate over a portion (e.g., sub-band, BWP) or all of a carrier bandwidth.

[0036] The signal waveform transmitted on a carrier may include multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)). In a system employing MCM techniques, a resource element may include one symbol period (e.g., the duration of one modulated symbol) and one subcarrier, where the symbol period and the subcarrier spacing are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the code rate of the modulation scheme, or both). Thus, the more resource elements the UE 115 receives and the higher the order of the modulation scheme, the higher the data rate of the UE 115 can be. Wireless communication resources may refer to a combination of radio frequency spectrum resources, time resources, and spatial resources (e.g., spatial layers or beams), and using multiple spatial layers can further increase the data rate or data integrity of the communication with the UE 115.

[0037] The time intervals of the base station 105 or the UE 115 can be expressed as multiples of a basic time unit, which may refer to, for example, the sampling period T s = 1 / (Δf max ·Nf) seconds, where Δf max may represent the maximum supported subcarrier spacing, and Nf may represent the maximum supported discrete Fourier transform (DFT) size. The time intervals of the communication resources may be organized according to radio frames each having a specified duration (e.g., 10 milliseconds (ms)). Each radio frame may be identified by a system frame number (SFN) (e.g., ranging from 0 to 1023).

[0038] Each frame may include multiple consecutively numbered subframes or time slots, and each subframe or time slot may have the same duration. In some examples, a frame may be divided (e.g., in the time domain) into subframes, and each subframe may be further divided into several time slots. Alternatively, each frame may include a variable number of time slots, and the number of time slots may depend on the subcarrier spacing. Each time slot may include several symbol periods (e.g., depending on the length of the cyclic prefix added before each symbol period). In some wireless communication systems 100, a time slot may be further divided into multiple mini-slots each containing one or more symbols. Excluding the cyclic prefix, each symbol period may contain one or more (e.g., Nf) sampling periods. The duration of the symbol period may depend on the subcarrier spacing or the operating frequency band.

[0039] A subframe, a slot, a mini-slot, or a symbol can be the smallest scheduling unit (e.g., in the time domain) of a wireless communication system 100 and can be referred to as a transmission time interval (TTI). In some examples, the duration of a TTI (e.g., the number of symbol periods in a TTI) can be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communication system 100 can be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs)).

[0040] Physical channels can be multiplexed on a carrier according to various techniques. The physical control channel and the physical data channel can be multiplexed on a downlink carrier using, for example, time division multiplexing (TDM) techniques, frequency division multiplexing (FDM) techniques, or one or more of hybrid TDM-FDM techniques. A control region (e.g., a control resource set (CORESET)) for the physical control channel can be defined by the number of symbol periods and can extend across the system bandwidth of the carrier or a subset of the system bandwidth. One or more control regions (e.g., CORESETs) can be configured for a set of UEs 115. For example, one or more of the UEs 115 can monitor or search a control region for control information according to one or more search space sets, and each search space set can include one or more control channel candidates in one or more aggregation levels arranged in a cascaded manner. The aggregation level for a control channel candidate can refer to the number of control channel resources (e.g., control channel elements (CCEs)) associated with the encoded information for a control information format having a given payload size. The search space set can include a common search space set configured to send control information to multiple UEs 115 and a UE-specific search space set for sending control information to a specific UE 115.

[0041] Each base station 105 can provide communication coverage via one or more cells (e.g., macro cells, small cells, hotspots, or other types of cells, or any combination thereof). The term "cell" can refer to a logical communication entity for communicating with a base station 105 (e.g., on a carrier) and can be associated with an identifier (e.g., a physical cell identifier (PCID), a virtual cell identifier (VCID), or others) for distinguishing adjacent cells. In some examples, a cell can also refer to a geographical coverage area 110 or a portion of the geographical coverage area 110 (e.g., a sector) on which the logical communication entity operates. The range of such cells can vary from a smaller area (e.g., a structure, a subset of a structure) to a larger area depending on various factors (such as the capabilities of the base station 105). For example, a cell can be or include a building, a subset of a building, or an external space between or overlapping with the geographical coverage area 110, and other examples.

[0042] Macro cells generally cover a relatively large geographical area (e.g., with a radius of several kilometers) and may allow unconstrained access to UEs 115 having a service subscription with the network provider supporting the macro cell. Small cells may be associated with lower power base stations 105 (compared to macro cells), and small cells may operate in the same or different (e.g., licensed, unlicensed) frequency bands as macro cells. Small cells may provide unconstrained access to UEs 115 having a service subscription with the network provider, or may provide constrained access to UEs 115 associated with the small cell (e.g., UEs 115 in a closed subscriber group (CSG), UEs 115 associated with users in a home or office). Base station 105 may support one or more cells and may also support communication on one or more cells using one or more component carriers.

[0043] In some examples, a carrier may support multiple cells and may be configured with different cells according to different protocol types that may provide access to different types of devices (e.g., MTC, narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB)).

[0044] In some examples, base station 105 may be mobile and thus provide communication coverage for a mobile geographical coverage area 110. In some examples, different geographical coverage areas 110 associated with different technologies may overlap, but different geographical coverage areas 110 may be supported by the same base station 105. In other examples, overlapping geographical coverage areas 110 associated with different technologies may be supported by different base stations 105. The wireless communication system 100 may include, for example, a heterogeneous network where different types of base stations 105 use the same or different radio access technologies to provide coverage for various geographical coverage areas 110.

[0045] Some UEs 115 (such as MTC or IoT devices) can be low-cost or low-complexity devices and can provide automated communication between machines (e.g., via machine-to-machine (M2M) communication). M2M communication or MTC can refer to data communication technologies that allow devices to communicate with each other or with a base station 105 without human intervention. In some examples, M2M communication or MTC can include communication from devices integrated with sensors or meters to measure or capture information and relay such information to a central server or application that utilizes the information or presents the information to a person interacting with the application. Some UEs 115 can be designed to collect information or implement automated behavior of machines or other devices. Examples of applications for MTC devices include: smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, field survival monitoring, weather and geographical event monitoring, queue management and tracking, remote security sensing, physical access control, and transaction-based commercial charging.

[0046] Some UEs 115 can be configured to operate in power-saving modes, such as half-duplex communication (e.g., a mode that supports one-way communication via transmission or reception but not simultaneous transmission and reception). In some examples, half-duplex communication can be performed at a reduced peak rate. Other power-saving techniques for UEs 115 include entering a deep sleep power-saving mode when not participating in active communication, operating on limited bandwidth (e.g., according to narrowband communication), or a combination of these techniques. For example, some UEs 115 can be configured for operation using a narrowband protocol type associated with a defined portion or range within a carrier, within a guard band of a carrier, or outside a carrier (e.g., a set of subcarriers or resource blocks (RBs)).

[0047] The wireless communication system 100 can be configured to support ultra-reliable communication or low-latency communication or various combinations thereof. For example, the wireless communication system 100 can be configured to support ultra-reliable low-latency communication (URLLC) or mission-critical communication. UEs 115 can be designed to support ultra-reliable, low-latency, or critical functions (e.g., mission-critical functions). Ultra-reliable communication can include private communication or group communication and can be supported by one or more mission-critical services (such as mission-critical push-to-talk (MCPTT), mission-critical video (MCVideo), or mission-critical data (MCData)). Support for mission-critical functions can include prioritization of services, and mission-critical services can be used for public safety or general commercial applications. The terms ultra-reliable, low-latency, mission-critical, and ultra-reliable low-latency can be used interchangeably herein.

[0048] In some examples, UE 115 may also be able to communicate directly with other UEs 115 over a device-to-device (D2D) communication link 135 (e.g., using peer-to-peer (P2P) or D2D protocols). One or more UEs 115 utilizing D2D communication may be within the geographic coverage area 110 of base station 105. Other UEs 115 in such a group may be outside the geographic coverage area 110 of base station 105 or may otherwise be unable to receive transmissions from base station 105. In some examples, groups of UEs 115 communicating via D2D communication may utilize a one-to-many (1:M) system, where each UE 115 transmits to every other UE 115 in the group. In some examples, base station 105 facilitates the scheduling of resources for D2D communication. In other cases, D2D communication is performed between UEs 115 without involving base station 105.

[0049] In some systems, D2D communication link 135 may be an example of a communication channel (such as a sidelink communication channel) between vehicles (e.g., UE 115). In some examples, vehicles may communicate using vehicle-to-everything (V2X) communication, vehicle-to-vehicle (V2V) communication, or some combination of these communications. Vehicles may signal information related to traffic conditions, signal scheduling, weather, safety, emergencies, or any other information related to the V2X system. In some examples, vehicles in a V2X system may communicate with roadside infrastructure (such as roadside units), or with a network, or with both, using vehicle-to-network (V2N) communication via one or more network nodes (e.g., base station 105).

[0050] Core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. Core network 130 may be an evolved packet core (EPC) or a 5G core (5GC), and the EPC or 5GC may include at least one control plane entity that manages access and mobility (e.g., a mobility management entity (MME), an access and mobility management function (AMF)), and at least one user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW), a packet data network (PDN) gateway (P-GW), or a user plane function (UPF)). The control plane entity may manage non-access stratum (NAS) functions such as the mobility, authentication, and bearer management of UEs 115 served by base station 105 associated with core network 130. User IP packets may be passed through the user plane entity, which may provide IP address allocation and other functions. The user plane entity may be connected to network operator IP services 150. Network operator IP services 150 may include access to the Internet, an intranet, an IP multimedia subsystem (IMS), or a packet-switched streaming service.

[0051] Some network devices (such as base station 105) may include sub-components, such as access network entity 140, which may be an example of an access node controller (ANC). Each access network entity 140 may communicate with each UE 115 via one or more other access network transmission entities 145, which may be referred to as radio heads, intelligent radio heads, or transmit / receive points (TRPs). Each access network transmission entity 145 may include one or more antenna panels. In some configurations, various functions of each access network entity 140 or base station 105 may be distributed across various network devices (e.g., radio heads and ANCs) or combined into a single network device (e.g., base station 105).

[0052] The wireless communication system 100 may operate using one or more frequency bands, typically in the range of 300 megahertz (MHz) to 300 gigahertz (GHz). Generally, the 300 MHz to 3 GHz division is known as the ultra-high frequency (UHF) division or the decimeter band because the wavelengths are in the range of approximately one decimeter to one meter in length. UHF waves may be blocked or redirected by buildings and environmental features, but these waves can sufficiently penetrate various structures for macrocells to provide service to UEs 115 located indoors. Compared to transmissions using smaller frequencies and longer waves in the high frequency (HF) or very high frequency (VHF) portions of the spectrum below 300 MHz, UHF wave transmissions may be associated with smaller antennas and shorter ranges (e.g., less than 100 kilometers).

[0053] The wireless communication system 100 may also operate in the super-high frequency (SHF) division of the spectrum from 3 GHz to 30 GHz (also known as the centimeter band) or in the extremely high frequency (EHF) division of the spectrum (e.g., from 30 GHz to 300 GHz) (also known as the millimeter band). In some examples, the wireless communication system 100 may support millimeter wave (mmW) communication between the UE 115 and the base station 105, and the EHF antennas of the corresponding devices may be smaller and more closely spaced than UHF antennas. In some examples, this may facilitate the use of antenna arrays within the devices. However, the propagation of EHF transmissions may experience even greater atmospheric attenuation and shorter ranges than SHF or UHF transmissions. The techniques disclosed herein may be employed across transmissions using one or more different frequency divisions, and the use of frequency bands designated across these frequency divisions may vary by country or regulatory body.

[0054] The wireless communication system 100 can utilize both licensed and unlicensed radio frequency bands. For example, the wireless communication system 100 can employ Licensed-Assisted Access (LAA), Long-Term Evolution Unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed band such as the 5 GHz Industrial, Scientific, and Medical (ISM) band. When operating in an unlicensed radio frequency band, devices such as base station 105 and UE 115 can employ carrier sensing for collision detection and avoidance. In some examples, operation in the unlicensed band can be based on a carrier aggregation configuration (e.g., LAA) in coordination with a component carrier operating in a licensed band. Operations in the unlicensed spectrum can include downlink transmissions, uplink transmissions, peer-to-peer (P2P) transmissions, or device-to-device (D2D) transmissions, etc.

[0055] Base station 105 or UE 115 can be equipped with multiple antennas, which can be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communication, or beamforming. The antennas of base station 105 or UE 115 can be located within one or more antenna arrays or antenna panels that can support MIMO operation or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays can be co-located at an antenna assembly such as an antenna tower. In some examples, the antennas or antenna arrays associated with base station 105 can be located at different geographical locations. Base station 105 can have an antenna array that has several rows and columns of antenna ports for beamforming that base station 105 can use to support communication with UE 115. Similarly, UE 115 can have one or more antenna arrays that can support various MIMO or beamforming operations. Additionally or alternatively, an antenna panel can support radio frequency beamforming for signals transmitted via the antenna ports.

[0056] Base station 105 or UE 115 can use MIMO communication to utilize multipath signal propagation and improve spectral efficiency by transmitting or receiving multiple signals via different spatial layers. Such techniques can be referred to as spatial multiplexing. For example, a transmitting device can transmit multiple signals via different antennas or different combinations of antennas. Similarly, a receiving device can receive multiple signals via different antennas or different combinations of antennas. Each of the multiple signals can be referred to as a separate spatial stream and can carry bits associated with the same data stream (e.g., the same codeword) or different data streams (e.g., different codewords). Different spatial layers can be associated with different antenna ports for channel measurement and reporting. MIMO techniques include single-user MIMO (SU-MIMO), where multiple spatial layers are transmitted to the same receiving device; and multi-user MIMO (MU-MIMO), where multiple spatial layers are transmitted to multiple devices.

[0057] Beamforming, which may also be referred to as spatial filtering, directional transmission, or directional reception, is a signal processing technique that can be used at a transmitting device or a receiving device (e.g., base station 105, UE 115) to shape or steer an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming can be achieved by combining signals communicated via the antenna elements of an antenna array such that some signals propagating in a particular orientation relative to the antenna array experience constructive interference while other signals experience destructive interference. Adjusting the signals communicated via the antenna elements can include the transmitting device or the receiving device applying an amplitude offset, a phase offset, or both to the signals carried via the antenna elements associated with the device. The adjustments associated with each antenna element can be defined by a set of beamforming weights associated with a particular orientation (e.g., relative to the antenna array of the transmitting device or the receiving device, or relative to some other orientation).

[0058] Wireless communication system 100 can be a packet-based network that operates according to a layered protocol stack. In the user plane, the communication of the bearer or packet data convergence protocol (PDCP) layer can be IP-based. The radio link control (RLC) layer can perform packet segmentation and reassembly for communication over logical channels. The media access control (MAC) layer can perform priority handling and multiplex logical channels into transport channels. The MAC layer can also use error detection techniques, error correction techniques, or both to support retransmissions at the MAC layer to improve link efficiency. In the control plane, the radio resource control (RRC) protocol layer can provide the establishment, configuration, and maintenance of an RRC connection that supports the radio bearers for user plane data between UE 115 and base station 105 or core network 130. In the physical layer, transport channels can be mapped to physical channels.

[0059] UE 115 and base station 105 can support retransmissions of data to increase the likelihood that the data is successfully received. Hybrid automatic repeat request (HARQ) feedback is a technique for increasing the likelihood that data is correctly received over communication link 125. HARQ can include a combination of error detection (e.g., using cyclic redundancy check (CRC)), forward error correction (FEC), and retransmission (e.g., automatic repeat request (ARQ)). HARQ can improve the throughput of the MAC layer in poor radio conditions (e.g., low signal-to-noise ratio conditions). In some examples, a device can support simultaneous slot HARQ feedback, where the device can provide HARQ feedback for data received in previous symbols in a particular slot during that slot. In other cases, the device can provide HARQ feedback in a subsequent slot or according to some other time interval.

[0060] In some cases, sidelink communication may be enabled between devices in a wireless communication system 100, such as between two or more UEs 115. In some cases, a transmitting UE 115 may determine a transport block size (TBS) for sidelink data channel transmission and provide an indication in the sidelink control information (SCI) to allow a receiving UE 115 to unambiguously determine the TBS to be used for decoding the sidelink communication. In some cases, the indication provided in the SCI may be an explicit indication in an information element as to whether a physical sidelink feedback channel (PSFCH) resource is included or excluded when determining the number of symbols used for TBS determination. In other cases, the indication provided in the SCI may be an implicit indication based on one or more values of one or more parameters provided in the SCI (e.g., one or more of a modulation and coding scheme (MCS) index, code rate, modulation order, channel data priority, or transmission type, etc.). In such cases, the sidelink UEs 115 may determine the same TBS across multiple instances of sidelink data channel transmissions that may be transmitted using time slots with different slot formats.

[0061] Figure 2 An example of a wireless communication system 200 that supports TBS determination for sidelink communication in accordance with aspects of the present disclosure is illustrated. In some examples, the wireless communication system 200 may implement aspects of the wireless communication system 100. In some examples, the wireless communication system 200 may implement aspects of the wireless communication system 100 and may include a base station 105-a and a group of UEs 115 (e.g., UEs 115-a to 115-c), which may be examples of the base station 105 and the UE 115, respectively, as referred to Figure 1 described. In some cases, the group of UEs 115 may communicate with each other via sidelink communication (e.g., within a vehicle-to-everything (V2X) system, a device-to-device (D2D) system, etc.).

[0062] According to some aspects, the group of UEs 115 may communicate with each other (or with another group of UEs 115) via sidelink communication 205 (e.g., using a peer-to-peer (P2P) or D2D protocol, such as a PC5 interface). For example, UE 115-a may monitor a resource pool for sidelink communication 205 from other UEs 115 in the group or an indication of sidelink communication 205 (e.g., resource reservation, control channel transmission, etc.). Additionally or alternatively, UE 115 may have data to be transmitted to one or more UEs 115 in the group and may use sidelink communication 205 to transmit the data. In some examples, in addition to an access link to the base station 105, the group of UEs 115 may also utilize a sidelink (e.g., sidelink communication 205).

[0063] For example, one or more UEs 115 may be located in the coverage area of the base station 105 (e.g., as referred to Figure 1in the coverage area 110). In such examples, the UE 115 may communicate with the base station 105 via the Uu interface (e.g., the base station 105 may transmit downlink communication to one or more UEs 115 via the access link 210). In some other examples, the group of UEs 115 may not be in the coverage area or may not communicate with the base station 105 using the access link. In some cases, the UE 115 may be configured to have one or more resource pools for sidelink communication 205.

[0064] In some cases, to enhance the reliability of the sidelink communication 205, the transmitting UE 115 may transmit multiple instances of the sidelink transmission. For example, an initial transmission of sidelink data may be transmitted in a first time slot, and a retransmission or repetition of the sidelink data transmission may be transmitted in a second time slot. Further, in some cases, the first time slot and the second time slot may have different time slot formats (e.g., due to a first time slot including sidelink feedback resources and a second time slot not including sidelink feedback resources). In such cases, the different time slot formats may result in different numbers of symbols available for sidelink data. In some cases, the different numbers of symbols in different time slots may result in different TBS calculations for different time slots.

[0065] For example, the transmitting and receiving UEs 115 may determine the number of available resource elements (REs) allocated for a data packet transmission, and then the TBS is determined based on the number of available REs and the MCS of the transmission. Further, both the transmitting and receiving UEs 115 should follow the same rules for TBS determination in order to provide consistent encoding and decoding at the transmitting and receiving UEs 115. Additionally, in cases where multiple repetitions of the transmission are used in accordance with aspects of the present disclosure, the first transmission and the retransmission also follow the same rules, so that the TBS is constant across multiple transmissions (e.g., enabling efficient decoding at the receiving UE 115 through techniques such as soft buffering or combining). Aspects of the present disclosure provide techniques for determining the TBS in cases where different time slot formats are used for different instances of sidelink transmission.

[0066] For example, the TBS determination may include determining the number of REs within a physical resource block (PRB) available for shared channel transmission, as follows:

[0067]

[0068] where is the number of subcarriers in the PRB, is the number of allocated OFDM symbols for the shared channel (e.g., PSSCH), is the number of REs for the demodulation reference signal (DMRS) per PRB in the scheduling resource, is an overhead value to be subtracted from the available REs (e.g., it can be configurable among {0, 6, 12, or 18}). After determining the available REs, UE 115 can determine the number of REs for shared channel transmission within a time slot as:

[0069] N RE = min(144, N′ RE ) · n PRB ,

[0070] where n PRB is the total number of allocated or reserved PRBs for shared channel transmission, and 144 is the maximum number of available REs for the shared channel in the PRBs in the sidelink (the maximum number of available OFDM symbols in the sidelink time slot is 12). Subsequently, UE 115 can determine the TBS based on the number of REs and MCS.

[0071] As discussed herein, in cases where different instances of shared channel transmission have different time slot formats, this TBS determination then depends on the number of shared channel symbols of the time slot. For example, UE 115 can reserve resources in M transmission opportunities (e.g., in M time slots) for M TB transmissions (i.e., the first transmission of the TB and M - 1 retransmissions). Further, the time slot format can be different across M time slots (e.g., some time slots can be configured with physical sidelink feedback channel (PSFCH) resources). Aspects of the present disclosure provide consistent TBS determination in such cases, so that the determined TBS is correct at the receiving UE 115 and is constant across multiple transmissions, regardless of whether there is a PSFCH resource configuration in the time slot. Figure 3 Illustrates examples of different time slot formats and sidelink data that can be transmitted in different time slots according to various aspects.

[0072] Figure 3 Illustrates an example of a sidelink time slot format 300 that supports TBS determination for sidelink communication according to aspects of the present disclosure. In some examples, the sidelink time slot format 300 can implement aspects of the wireless communication system 100 or 200. In some examples, the sidelink time slot format 300 can correspond to a resource grid that can be a function of the frequency domain and the time domain.

[0073] In Figure 3In the example, the resource grid may include several time slots n, such as time slot (n) 305, time slot (n + 1) 310, time slot (n + 2) 315, and time slot (n + 3) 320. Each time slot may include several time and frequency resources. For example, each time slot n may have several symbols and subcarriers. In this example, time slot (n) 305 may include an initial transmission 325 of sidelink data. Further, time slot (n) 305 includes feedback resources 340 (e.g., PSFCH resources that can be configured every 1 / 2 / 4 time slots, where every 2 time slots are illustrated in this example), and thus the sidelink shared channel resources do not occupy the last four symbols of the time slot. The transmitting UE in this example may be configured to transmit two repetitions of the transmission, and in this example, the first repetition 330 may be transmitted in time slot (n + 1) 310 while the second repetition 330 may be transmitted in time slot (n + 2) 315. In this example, time slot (n + 1) 310 may not be configured with any feedback resources 340, and thus has a different time slot format from time slot (n) 305 and time slot (n + 2) 315. In some cases, retransmissions may depend on HARQ feedback, and in other cases (such as Figure 3 illustrated), retransmissions may provide blind repetitions 330 to improve reliability. The transmitting UE may reserve sidelink resources for retransmissions when transmitting the first / initial transmission 325. In other cases, multiple transmissions may be non-consecutive in time (i.e., they may be in non-consecutive time slots).

[0074] According to various aspects discussed herein, the control resource 335 may include an SCI, which may include an indication of a slot format to be used to determine the TBS applied to the initial transmission 325 and the repetition 330 of sidelink data transmission. In some cases, the SCI may explicitly or implicitly indicate whether the number of REs for the TBS determination excludes sidelink feedback channel (e.g., PSFCH) resources. In some cases, the number of OFDM symbols for the TBS determination is determined at least in part based on an explicit signaling indication in the SCI (e.g., a parameter with one or more bits in the SCI indicates whether the PSFCH resources are included or excluded for the TBS determination). In other cases, the number of OFDM symbols for the TBS determination may be implicitly indicated in the SCI based on other information / parameters related to the sidelink data (e.g., PSSCH) transmission. Thus, in cases where the PSFCH resources are excluded during the TBS determination, the actual code rate in the slot with the PSFCH will be the same (or similar) to the nominal code rate (i.e., the code rate indicated by the MCS), and since there are more actual available REs for the PSSCH, the actual code rate in the slot without the PSFCH resources will be less than the nominal code rate. Similarly, when the PSFCH resources are not excluded during the TBS determination, since there are fewer actual available REs for the PSSCH, the actual code rate in the slot with the PSFCH resources will be greater than the nominal code rate, and the actual code rate in the slot without the PSFCH resources will be the same as or similar to the nominal code rate indicated by the MCS.

[0075] In a case where the SCI provides an explicit indication as to whether the feedback resource 340 is included or excluded at the time of TBS determination, this indication may be provided, for example, as a 1-bit parameter in the SCI to indicate whether the PSFCH resource is excluded. In some cases, this parameter may be carried in the first-phase SCI (e.g., via the PSCCH), or in the second-phase SCI (e.g., via the sidelink control information multiplexed in the PSSCH). In some cases, the transmitting UE may determine whether the feedback resource 340 should be excluded based on one or more rules (e.g., rules that may be preconfigured or configured when establishing the sidelink resource pool), and thus determine the value of the explicit indication in the SCI. In some cases, if the time slot for the initial transmission 325 of data is configured with the feedback resource 340, the transmitting UE may determine that the feedback resource 340 is excluded at the time of TBS determination. In other cases, if at least one of the time slots with resources reserved by the transmitting UE for data is configured with the feedback resource 340, the transmitting UE may determine that the feedback resource is excluded. In a further case, a decision as to whether to exclude the feedback resource 340 at the time of TBS determination may be made by the transmitting UE, and thus the SCI indication parameter is set. In other cases, the base station scheduling the sidelink transmission may provide the transmitting UE with information as to whether the feedback resource is excluded for TBS determination. The receiving UE may then perform TBS size determination for decoding the sidelink data transmission based at least on the indication in the SCI.

[0076] In a case where the SCI provides an implicit indication as to whether the feedback resource 340 is to be included or excluded at the time of TBS determination, one or more SCI parameters may be used to provide this indication. In some cases, the indicated MCS for the sidelink data transmission may provide this indication. For example, if the code rate in the MCS is greater than a code rate threshold (e.g., a predefined / (pre)configured code rate threshold), the feedback resource 340 may be excluded at the time of TBS determination. In some cases, if the MCS index is greater than an MCS index threshold (e.g., a predefined / (pre)configured MCS index threshold from one or more MCS tables available for sidelink communication), the feedback resource 340 may be excluded. In some cases, if the modulation order is higher than a modulation order index, the feedback resource 340 may be excluded (e.g., for an MCS with 64QAM or a higher modulation order, the feedback resource 340 is excluded). In a further case, a predefined or (pre)configured set of MCS indices may be used to indicate whether the feedback resource 340 is excluded at the time of TBS determination (e.g., if the MCS for the sidelink transmission is in the MCS set, the feedback resource is excluded at the time of TBS determination). In some cases, if the code rate is relatively large, the values of one or more thresholds or the selection of the MCS index may be chosen to exclude the feedback resource 340 for TBS determination such that a larger actual code rate can be avoided.

[0077] Additionally or alternatively, the SCI may provide an implicit indication via one or more other parameters, such as the priority of data transmission or the transmission mode. In some cases, the priority may be indicated in the SCI, and if the data priority is higher than a priority threshold, the feedback resource 340 may be excluded from the TBS determination. In some cases, the transmission mode may be unicast, multicast, or broadcast, and if the transmission mode is broadcast, or if the transmission mode is broadcast or multicast, the feedback resource 340 may be excluded from the TBS determination. In some cases, the indication of the transmission mode may be implied by the second-phase SCI format. That is, the unicast, multicast, and broadcast transmission modes have different second-phase SCI formats, and this format may be used to determine the transmission mode. Thus, whether to include or exclude the feedback resource 340 in such cases may be based on the second-phase SCI format. Excluding the feedback resource 340 in such cases may help avoid a higher actual coding rate for traffic with a higher priority or traffic that is broadcast / multicast.

[0078] In some cases, if it is determined that the feedback resource 340 is excluded during TBS determination, the parameter (i.e., the number of OFDM symbols allocated for PSSCH transmission) may be determined as Q, otherwise this parameter may be determined as Q + 3. For example, if the feedback resource 340 is excluded during TBS determination, for a normal cyclic prefix (CP) time slot, (i.e., Q = 9) (likewise, for an extended CP, ), and if the feedback resource 340 is not excluded during TBS determination, for a normal CP time slot, (or 10 for an extended CP time slot).

[0079] Figure 4 An example of a process flow 400 that supports TBS determination for sidelink communication in accordance with various aspects of the present disclosure is illustrated. In some examples, the process flow 400 may implement aspects of the wireless communication system 100 or 200. The process flow 400 may be implemented by a transmitting UE 115-d and a receiving UE 115-e, which may be examples of the UE 115 as described herein. Alternative examples may be implemented, where some steps are performed in a different order than described or not performed at all. In some cases, the steps may include additional features not mentioned below, or further steps may be added.

[0080] Optionally, at 405, a transmitting UE 115-d (which may be an example of the first UE or the first sidelink communication device discussed herein) may establish a sidelink communication connection with a receiving UE 115-e (which may be an example of the second UE or the second sidelink communication device discussed herein). In some cases, the sidelink communication may be unicast communication. In other cases, the sidelink communication may be broadcast or multicast communication to multiple UEs 115. For example, the transmitting UE 115-d may be a group leader for a sidelink multicast communication and may identify several other receiving UEs 115-e as group members for the multicast communication. In cases where the sidelink communication is broadcast communication, it may not be possible to establish a sidelink communication connection with the receiving UE 115-e. In some cases, the transmitting UE 115-d may reserve sidelink resources for one or more transmissions, which may include one or more blind repetitions of an initial transmission in some cases to help increase reliability. Optionally, at 410, in cases where the communication may use beamformed communication, one or more beam training procedures may be performed.

[0081] At 415, the transmitting UE 115-d may identify sidelink data for transmission to the receiving UE 115-e or multiple receiving UEs 115e. In some cases, the sidelink data may be high-priority data or high-reliability data, and the transmitting UE 115-d may determine that one or more repetitions of the data are to be transmitted.

[0082] At 420, the transmitting UE 115-d may determine a time slot format for an initial transmission of the data and for one or more retransmissions of the data. In some cases, the time slot format for the initial transmission and one or more retransmissions may differ based on one of the time slots including PSFCH resources. At 425, the transmitting UE 115-d may determine a TBS for the data transmission, which may be the same TBS across multiple time slots. In some cases, the TBS may be determined based on one or more rules for excluding or including PSFCH resources when determining the TBS, such as those discussed herein.

[0083] At 430, the transmitting UE 115-d may format the SCI and PSSCH data for transmission according to the determined TBS. In some cases, the transmitting UE 115-d may set an explicit indication in the SCI indicating how the receiving UE 115-e is to determine the TBS. In other cases, the TBS may be determined based on one or more implicit indications in the SCI. When formatting the PSSCH, the transmitting UE 115-d may encode the sidelink data according to the determined TBS. At 435, the transmitting UE115-d may transmit the SCI and the initial data transmission to the receiving UE 115-e.

[0084] At 440, the receiving UE 115-e may decode the SCI received from the transmitting UE 115-d. In some cases, the receiving UE 115-e may buffer the sidelink communication and decode the SCI from the configured SCI resources within the sidelink resources including the sidelink communication. The receiving UE 115-e may identify from the SCI an indication of how to determine the TBS, such as the explicit indication or implicit indication discussed herein. At 445, the receiving UE 115-e may determine the TBS of the sidelink data transmission based on the indication provided in the SCI. At 450, the receiving UE 115-e may decode the sidelink data transmission based on the determined TBS.

[0085] Optionally, at 455, the transmitting UE 115-e may transmit one or more retransmissions of the sidelink data along with the associated SCI. At 460, the receiving UE 115-e may optionally decode the SCI and the sidelink data based on the TBS determined from the indication in the SCI. Optionally, at 465, the receiving UE 115-e may transmit an acknowledgement / negative acknowledgement (ACK / NACK) feedback (e.g., HARQ feedback) to the transmitting UE 115-e according to the feedback technique used for acknowledging the communication.

[0086] Figure 5 FIG. 500 is a block diagram of a device 505 supporting TBS determination for sidelink communication in accordance with aspects of the present disclosure. The device 505 may be an example of aspects of the UE 115 described herein. The device 505 may include a receiver 510, a communication manager 515, and a transmitter 520. The device 505 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0087] The receiver 510 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to TBS determination for sidelink communication, etc.). The information may be passed to other components of the device 505. The receiver 510 may be an example of aspects of the transceiver 820 described with reference to Figure 8 The receiver 510 may utilize a single antenna or an antenna array.

[0088] In a scenario where device 505 is a first sidelink communication device receiving sidelink communication, communication manager 515 may receive an SCI for a sidelink data channel transmission from a second sidelink communication device, and decode the sidelink data channel transmission based on the TBS of the sidelink data channel transmission, where the TBS is determined based on an indication in the SCI. Communication manager 515 may be an example of aspects of communication manager 810 described herein.

[0089] In a scenario where device 505 is a second sidelink communication device transmitting sidelink communication, communication manager 515 may identify sidelink data to be transmitted to at least a first sidelink communication device in a sidelink data channel transmission from the second sidelink communication device, determine a TBS for the sidelink data channel transmission based on a time slot format of one or more time slots reserved for transmitting the sidelink data channel transmission, transmit the sidelink data channel transmission to the first sidelink communication device, where the sidelink data is encoded in the sidelink data channel transmission according to the determined TBS, and transmit an SCI indicating the time slot format for TBS determination of the sidelink data channel transmission. Communication manager 515 may be an example of aspects of communication manager 810 described herein.

[0090] Communication manager 515 or its sub-components may be implemented in hardware, code executed by a processor (e.g., software or firmware), or any combination thereof. If implemented in code executed by a processor, the functions of communication manager 515 or its sub-components may be performed by a general-purpose processor, DSP, application specific integrated circuit (ASIC), FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in this disclosure.

[0091] Communication manager 515 or its sub-components may be physically located at various positions, including being distributed such that portions of the functions are implemented by one or more physical components at different physical locations. In some examples, according to aspects of this disclosure, communication manager 515 or its sub-components may be separate and distinct components. In some examples, according to various aspects of this disclosure, communication manager 515 or its sub-components may be combined with one or more other hardware components, including but not limited to input / output (I / O) components, transceivers, network servers, another computing device, one or more other components described in this disclosure, or combinations thereof.

[0092] Transmitter 520 may transmit signals generated by other components of device 505. In some examples, transmitter 520 may be co-located with receiver 510 in a transceiver module. For example, transmitter 520 may be with reference to Figure 8Examples of aspects of the transceiver 820 described. The transmitter 520 may utilize a single antenna or an antenna array.

[0093] Figure 6 FIG. 600 is a block diagram of a device 605 supporting TBS determination for sidelink communication in accordance with aspects of the present disclosure. The device 605 may be an example of aspects of the device 505 or UE 115 described herein. The device 605 may include a receiver 610, a communication manager 615, and a transmitter 640. The device 605 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0094] The receiver 610 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to TBS determination for sidelink communication, etc.). The information may be passed to other components of the device 605. The receiver 610 may be an example of aspects of the transceiver 820 described Figure 8 Examples of aspects of the transceiver 820 described. The receiver 610 may utilize a single antenna or an antenna array.

[0095] The communication manager 615 may be an example of aspects of the communication manager 515 described herein. The communication manager 615 may include an SCI manager 620, a decoder 625, a sidelink data manager 630, and a TB size manager 635. The communication manager 615 may be an example of aspects of the communication manager 810 described herein.

[0096] In a case where the device 605 is a first sidelink communication device receiving sidelink communication, the SCI manager 620 may receive an SCI for a sidelink data channel transmission from a second sidelink communication device. The decoder 625 may decode the sidelink data channel transmission based on the TBS of the sidelink data channel transmission, where the TBS is determined based on an indication in the SCI.

[0097] In a scenario where device 605 is a second sidelink communication device transmitting sidelink communication, the sidelink data manager 630 may identify sidelink data to be transmitted to at least a first sidelink communication device in a sidelink data channel transmission from the second sidelink communication device, and transmit a sidelink data channel transmission to the first sidelink communication device, where the sidelink data is encoded in the sidelink data channel transmission according to a determined TBS. The TB size manager 635 may determine the TBS for the sidelink data channel transmission based on the time slot format of one or more time slots reserved for transmitting the sidelink data channel transmission. The SCI manager 620 may transmit to the first sidelink communication device an SCI indicating the time slot format for TBS determination for the sidelink data channel transmission.

[0098] The transmitter 640 may transmit signals generated by other components of device 605. In some examples, the transmitter 640 may be co-located with the receiver 610 in a transceiver module. For example, the transmitter 640 may be an example of aspects of the transceiver 820 described with reference to Figure 8 The transmitter 640 may utilize a single antenna or an antenna array.

[0099] Figure 7 Block diagram 700 illustrates a communication manager 705 supporting TBS determination for sidelink communication in accordance with aspects of the present disclosure. The communication manager 705 may be an example of aspects of the communication manager 515, the communication manager 615, or the communication manager 810 described herein. The communication manager 705 may include an SCI manager 710, a decoder 715, a TB size manager 720, a feedback channel manager 725, and a sidelink data manager 730. Each of these modules may communicate directly or indirectly with each other (e.g., via one or more buses).

[0100] The SCI manager 710 may receive an SCI for a sidelink data channel transmission from the second sidelink communication device.

[0101] In some examples, the SCI manager 710 may transmit to the first sidelink communication device an SCI indicating the time slot format for TBS determination for the sidelink data channel transmission.

[0102] In some cases, the indication in the SCI is an explicit indication as to whether feedback channel resources within a transmission time slot are to be used for TBS determination. In some cases, the explicit indication includes one or more bits in the SCI that indicate whether the feedback channel resources are to be included or excluded in determining the TBS. In some cases, the explicit indication is provided in a first-phase SCI received in sidelink control channel communication, in a second-phase SCI multiplexed with sidelink data in sidelink shared channel communication, or a combination thereof.

[0103] In some cases, the indication in the SCI is an implicit indication as to whether the feedback channel resources within the transmission time slot are to be used for TBS determination. In some cases, the implicit indication is based on the modulation and coding scheme (MCS) used for sidelink data transmission. In some cases, the implicit indication is based on one or more values of one or more parameters of the sidelink grant for sidelink data channel transmission provided by the SCI. In some cases, the one or more parameters include the data priority of the sidelink data channel transmission, and wherein when the data priority exceeds a data priority threshold, the feedback channel resources are excluded in determining the TBS. In some cases, the one or more parameters indicate that the sidelink data channel transmission is a unicast transmission, a multicast transmission, or a broadcast transmission, and wherein when the sidelink data channel transmission is a multicast transmission or a broadcast transmission, the feedback channel resources are excluded in determining the TBS.

[0104] The decoder 715 may decode the sidelink data channel transmission based on the TBS of the sidelink data channel transmission, wherein the TBS is determined based on the indication in the SCI.

[0105] The TB size manager 720 may determine the TBS for the sidelink data channel transmission based on the time slot format of one or more time slots reserved for transmitting the sidelink data channel transmission. In some examples, the TB size manager 720 may determine the TBS based on the number of orthogonal frequency division multiplexing (OFDM) symbols associated with the sidelink data channel transmission within the time slot, and wherein the number of OFDM symbols is determined based on the indication in the SCI. In some examples, the TB size manager 720 may determine the number of orthogonal frequency division multiplexing (OFDM) symbols within one or more time slots reserved for transmitting the sidelink data channel transmission based on the time slot format.

[0106] In some cases, the indication in the SCI at least indicates whether the first time slot format or the second time slot format is used for TBS determination. In some cases, the first time slot format includes a first number of orthogonal frequency division multiplexing (OFDM) symbols available for shared channel transmission, while the second time slot format includes a second number of OFDM symbols less than the first number of OFDM symbols available for shared channel transmission. In some cases, the first value or the second value of the number of OFDM symbols is used to determine the TBS based on the indication that identifies whether one or more OFDM symbols configured to provide feedback transmission in one or more time slots are to be included or excluded in determining the TBS.

[0107] The sidelink data manager 730 may identify sidelink data to be transmitted to at least a first sidelink communication device in a sidelink data channel transmission from a second sidelink communication device. In some examples, the sidelink data manager 730 may transmit a sidelink data channel transmission to the first sidelink communication device, wherein the sidelink data is encoded in the sidelink data channel transmission according to the determined TBS.

[0108] The feedback channel manager 725 may identify sidelink feedback channel resources. In some cases, when the code rate of the MCS exceeds a code rate threshold, the feedback channel resources are excluded when determining the TBS, and when the code rate is at or below the code rate threshold, the feedback channel resources are included when determining the TBS. In some cases, when the MCS index provided in the SCI exceeds an MCS index threshold, the feedback channel resources are excluded when determining the TBS, and when the MCS index is at or below the MCS index threshold, the feedback channel resources are included when determining the TBS. In some cases, when the modulation order of the MCS exceeds a modulation order threshold, the feedback channel resources are excluded when determining the TBS, and when the modulation order is at or below the modulation order threshold, the feedback channel resources are included when determining the TBS. In some cases, when the MCS index provided in the SCI is in a predetermined set of MCS index values, the feedback channel resources are excluded when determining the TBS, and when the MCS index is outside the predetermined set of MCS index values, the feedback channel resources are included when determining the TBS.

[0109] In some cases, when the time slot for the initial sidelink data channel transmission includes feedback channel resources, the feedback channel resources are excluded when determining the TBS, and when the time slot for the initial sidelink data channel transmission does not include feedback channel resources, the feedback channel resources are included when determining the TBS. In some cases, when at least one time slot having resources reserved for sidelink data channel transmission includes feedback channel resources, the feedback channel resources are excluded when determining the TBS, and when all time slots having resources reserved for sidelink data channel transmission do not include feedback channel resources, the feedback channel resources are included when determining the TBS.

[0110] Figure 8FIG. 800 shows a diagram of a system 800 including a device 805 that supports TBS determination for sidelink communication according to aspects of the present disclosure. The device 805 may be an example of the device 505, the device 605, or the UE 115 described herein or include components of the device 505, the device 605, or the UE 115. The device 805 may include components for two-way voice and data communication, which include components for transmitting and receiving communication, including a communication manager 810, an I / O controller 815, a transceiver 820, an antenna 825, a memory 830, and a processor 840. These components may be in electronic communication via one or more buses (e.g., bus 845).

[0111] In some cases, the communication manager 810 may receive an SCI for a sidelink data channel transmission from a second sidelink communication device and decode the sidelink data channel transmission based on the TBS of the sidelink data channel transmission, where the TBS is determined based on an indication in the SCI.

[0112] In some cases, the communication manager 810 may identify sidelink data to be transmitted to at least a first sidelink communication device in a sidelink data channel transmission from a second sidelink communication device, transmit the sidelink data channel transmission to the first sidelink communication device, where the sidelink data is encoded in the sidelink data channel transmission according to the determined TBS, determine the TBS for the sidelink data channel transmission based on the time slot format of one or more time slots reserved for transmitting the sidelink data channel transmission, and transmit an SCI indicating the time slot format for TBS determination of the sidelink data channel transmission to the first sidelink communication device.

[0113] The I / O controller 815 may manage input and output signals of the device 805. The I / O controller 815 may also manage peripheral devices not integrated into the device 805. In some cases, the I / O controller 815 may represent a physical connection or port to an external peripheral device. In some cases, the I / O controller 815 may utilize an operating system, such as or another known operating system. In other cases, the I / O controller 815 may represent or interact with a modem, a keyboard, a mouse, a touch screen, or similar devices. In some cases, the I / O controller 815 may be implemented as part of a processor. In some cases, a user may interact with the device 805 via the I / O controller 815 or via hardware components controlled by the I / O controller 815.

[0114] The transceiver 820 can perform two-way communication via one or more antennas, wired or wireless links, as described above. For example, the transceiver 820 can represent a wireless transceiver and can perform two-way communication with another wireless transceiver. The transceiver 820 can also include a modem to modulate packets and provide the modulated packets to the antenna for transmission, and to demodulate packets received from the antenna.

[0115] In some cases, the wireless device can include a single antenna 825. However, in some cases, the device can have more than one antenna 825, which can be capable of concurrently transmitting or receiving multiple wireless transmissions.

[0116] The memory 830 can include RAM and ROM. The memory 830 can store computer-readable, computer-executable code 835 that includes instructions that, when executed, cause the processor to perform the various functions described herein. In some cases, the memory 830 can particularly include a BIOS that can control basic hardware or software operations, such as interactions with peripheral components or devices.

[0117] The processor 840 can include intelligent hardware devices (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, programmable logic devices, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, the processor 840 can be configured to operate a memory array using a memory controller. In other cases, the memory controller can be integrated into the processor 840. The processor 840 can be configured to execute computer-readable instructions stored in a memory (e.g., the memory 830) to cause the device 805 to perform various functions (e.g., functions or tasks supporting TBS determination for sidelink communication).

[0118] The code 835 can include instructions for implementing aspects of the present disclosure, including instructions for supporting wireless communication. The code 835 can be stored in a non-transitory computer-readable medium, such as system memory or other types of memory. In some cases, the code 835 may not be directly executable by the processor 840, but can cause a computer (e.g., when compiled and executed) to perform the functions described herein.

[0119] Figure 9 A flowchart of a method 900 for supporting TBS determination for sidelink communication in accordance with aspects of the present disclosure is shown. The operations of method 900 can be implemented by a UE 115 or its components (which can be a first sidelink communication device) as described herein. For example, the operations of method 900 can be performed by a device as referred to in Figures 5 to 8be performed by the described communication manager. In some examples, the UE may execute an instruction set to control functional elements of the UE to perform the following functions. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the following functions.

[0120] At 905, a first sidelink communication device may receive, from a second sidelink communication device, an SCI for a sidelink data channel transmission from the second sidelink communication device. The operation of 905 may be performed according to the methods described herein. In some examples, aspects of the operation of 905 may be performed by an SCI manager as described with reference to Figures 5 to 8 the described SCI manager.

[0121] At 910, a first sidelink communication device may decode the sidelink data channel transmission based on the TBS of the sidelink data channel transmission, where the TBS is determined based on an indication in the SCI. The operation of 910 may be performed according to the methods described herein. In some examples, aspects of the operation of 910 may be performed by a decoder as described with reference to Figures 5 to 8 the described decoder.

[0122] Figure 10 FIG. 1000 is a flow diagram of a method 1000 that supports TBS determination for sidelink communication in accordance with aspects of the present disclosure. The operations of method 1000 may be implemented by a UE 115 or components thereof (which may be a first sidelink communication device) as described herein. For example, the operations of method 1000 may be performed by a communication manager as described with reference to Figures 5 to 8 the described communication manager. In some examples, the UE may execute an instruction set to control functional elements of the UE to perform the following functions. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the following functions.

[0123] At 1005, a first sidelink communication device may receive, from a second sidelink communication device, an SCI for a sidelink data channel transmission from the second sidelink communication device. The operation of 1005 may be performed according to the methods described herein. In some examples, aspects of the operation of 1005 may be performed by an SCI manager as described with reference to Figures 5 to 8 the described SCI manager.

[0124] At 1010, a first sidelink communication device may determine the TBS based on the number of OFDM symbols within a time slot associated with the sidelink data channel transmission, where the number of OFDM symbols is determined based on an indication in the SCI. The operation of 1010 may be performed according to the methods described herein. In some examples, aspects of the operation of 1010 may be performed by a TB size manager as described with reference to Figures 5 to 8 the described TB size manager.

[0125] At 1015, the first sidelink communication device may decode the sidelink communication transmission based on the determined TBS. The operations at 1015 may be performed according to the methods described herein. In some examples, aspects of the operations at 1015 may be performed by a TB size manager as described with reference to Figures 5 to 8 as described.

[0126] Figure 11 FIG. 1100 is a flow diagram of a method for supporting TBS determination for sidelink communication in accordance with aspects of the present disclosure. The operations of method 1100 may be implemented by a UE 115 or components thereof (which may be an example of a second sidelink communication device) as described herein. For example, the operations of method 1100 may be performed by a communication manager as described with reference to Figures 5 to 8 as described. In some examples, the UE may execute an instruction set to control functional elements of the UE to perform the following functions. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the following functions.

[0127] At 1105, the second sidelink communication device may identify sidelink data to be transmitted to at least the first sidelink communication device in a sidelink data channel transmission from the second sidelink communication device. The operations at 1105 may be performed according to the methods described herein. In some examples, aspects of the operations at 1105 may be performed by a sidelink data manager as described with reference to Figures 5 to 8 as described.

[0128] At 1110, the second sidelink communication device may determine a TBS for the sidelink data channel transmission based on the time slot format of one or more time slots reserved for the transmission of the sidelink data channel transmission. The operations at 1110 may be performed according to the methods described herein. In some examples, aspects of the operations at 1110 may be performed by a TB size manager as described with reference to Figures 5 to 8 as described.

[0129] At 1115, the second sidelink communication device may transmit to the first sidelink communication device an SCI indicating the time slot format for the TBS determination for the sidelink data channel transmission. The operations at 1115 may be performed according to the methods described herein. In some examples, aspects of the operations at 1115 may be performed by an SCI manager as described with reference to Figures 5 to 8 as described.

[0130] At 1120, the second sidelink communication device may transmit a sidelink data channel transmission to the first sidelink communication device, wherein the sidelink data is encoded in the sidelink data channel transmission according to the determined TBS. The operations at 1120 may be performed according to the methods described herein. In some examples, aspects of the operations at 1120 may be performed by a... as described with reference to Figures 5 to 8performed by the described sidelink data manager.

[0131] Figure 12 FIG. 1200 is a flow diagram of a method 1200 that supports TBS determination for sidelink communication in accordance with aspects of the present disclosure. Operations of method 1200 may be implemented by a UE 115 or components thereof (which may be an example of a second sidelink communication device) as described herein. For example, operations of method 1200 may be performed by a communication manager as described with reference to Figures 5 to 8 the described communication manager. In some examples, the UE may execute an instruction set to control functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use special purpose hardware to perform aspects of the functions described below.

[0132] At 1205, the second sidelink communication device may identify sidelink data to be transmitted to at least a first sidelink communication device in a sidelink data channel transmission from the second sidelink communication device. The operation of 1205 may be performed in accordance with methods described herein. In some examples, aspects of the operation of 1205 may be performed by a sidelink data manager as described with reference to Figures 5 to 8 the described sidelink data manager.

[0133] At 1210, the second sidelink communication device may determine the number of OFDM symbols within one or more time slots reserved for transmission of the sidelink data channel transmission based on the slot format. The operation of 1210 may be performed in accordance with methods described herein. In some examples, aspects of the operation of 1210 may be performed by a TB size manager as described with reference to Figures 5 to 8 the described TB size manager.

[0134] At 1215, the second sidelink communication device may determine the TBS based on the number of OFDM symbols. The operation of 1215 may be performed in accordance with methods described herein. In some examples, aspects of the operation of 1215 may be performed by a TB size manager as described with reference to Figures 5 to 8 the described TB size manager.

[0135] At 1220, the second sidelink communication device may transmit to the first sidelink communication device a SCI indicating the slot format for TBS determination for the sidelink data channel transmission. The operation of 1220 may be performed in accordance with methods described herein. In some examples, aspects of the operation of 1220 may be performed by a SCI manager as described with reference to Figures 5 to 8 the described SCI manager.

[0136] At 1225, a second sidelink communication device may transmit a sidelink data channel transmission to a first sidelink communication device, where the sidelink data is encoded in the sidelink data channel transmission according to a determined TBS. The operation of 1225 may be performed according to the methods described herein. In some examples, aspects of the operation of 1225 may be performed by a sidelink data manager as described with reference to Figures 5 to 8 as described.

[0137] It should be noted that the methods described herein describe possible implementations, and the operations and steps may be rearranged or otherwise modified and other implementations are possible. In addition, aspects from two or more methods may be combined.

[0138] Aspects of the following examples may be combined with any of the previous embodiments or aspects described herein.

[0139] Example 1 is a method for wireless communication at a first sidelink communication device, the method comprising: receiving sidelink control information for a sidelink data channel transmission from a second sidelink communication device, and decoding the sidelink data channel transmission at least in part based on a transport block size of the sidelink data channel transmission, where the transport block size is determined at least in part based on an indication in the sidelink control information.

[0140] In Example 2, the method of Example 1 may include, where the indication in the sidelink control information indicates at least whether a first time slot format or a second time slot format is used to determine the transport block size.

[0141] In Example 3, the method of Examples 1-2 may include, where the first time slot format includes a first number of OFDM symbols available for shared channel transmission, and the second time slot format includes a second number of OFDM symbols less than the first number of OFDM symbols available for shared channel transmission.

[0142] In Example 4, the method of Examples 1-3 may include, where the indication in the sidelink control information is an explicit indication as to whether a feedback channel resource within a transmission time slot is to be used to determine the transport block size.

[0143] In Example 5, the method of Example 4 may include, where the explicit indication includes one or more bits in the sidelink control information that indicate whether the feedback channel resource is included or excluded in determining the transport block size.

[0144] In Example 6, the method of Examples 4-5 may include, where the explicit indication is provided in first stage sidelink control information received in sidelink control channel communication, in second stage sidelink control information multiplexed with sidelink data in sidelink shared channel communication, or a combination thereof.

[0145] In Example 7, the method of Examples 1 - 6 may include, wherein the indication in the sidelink control information is an implicit indication as to whether feedback channel resources within a transmission time slot are to be used to determine the transmission block size.

[0146] In Example 8, the method of Example 7 may include, wherein the implicit indication is based on the MCS used for sidelink data transmission.

[0147] In Example 9, the method of Example 8 may include, wherein when the code rate of the MCS exceeds a code rate threshold, the feedback channel resources are excluded when determining the transmission block size, and when the code rate is at or below the code rate threshold, the feedback channel resources are included when determining the transmission block size.

[0148] In Example 10, the method of Examples 8 - 9 may include, wherein when the MCS index provided in the sidelink control information exceeds an MCS index threshold, the feedback channel resources are excluded when determining the transmission block size, and when the MCS index is at or below the MCS index threshold, the feedback channel resources are included when determining the transmission block size.

[0149] In Example 11, the method of Examples 8 - 10 may include, wherein when the modulation order of the MCS exceeds a modulation order threshold, the feedback channel resources are excluded when determining the transmission block size, and when the modulation order is at or below the modulation order threshold, the feedback channel resources are included when determining the transmission block size.

[0150] In Example 12, the method of Examples 8 - 10 may include, wherein when the MCS index provided in the sidelink control information is within a predetermined set of MCS index values, the feedback channel resources are excluded when determining the transmission block size, and when the MCS index is outside the predetermined set of MCS index values, the feedback channel resources are included when determining the transmission block size.

[0151] In Example 13, the method of Examples 7 - 12 may include, wherein the implicit indication is based on one or more values of one or more parameters of a sidelink grant provided by the sidelink control information for sidelink data channel transmission.

[0152] In Example 14, the method of Example 13 may include, wherein the one or more parameters include the data priority of the sidelink data channel transmission, and wherein when the data priority exceeds a data priority threshold, the feedback channel resources are excluded when determining the transmission block size.

[0153] In Example 15, the method of Examples 13 - 14 may include, wherein the one or more parameters indicate that the sidelink data channel transmission is a unicast transmission, a multicast transmission, or a broadcast transmission, and wherein when the sidelink data channel transmission is a multicast transmission or a broadcast transmission, the feedback channel resources are excluded when determining the transport block size.

[0154] In Example 16, the method of Examples 1 - 15 may further include determining the transport block size at least in part based on the number of orthogonal frequency - division multiplexing (OFDM) symbols associated with the sidelink data channel transmission within a time slot, and wherein the number of OFDM symbols is determined based on an indication in the sidelink control information.

[0155] In Example 17, the method of Example 16 may include, wherein a first value or a second value of the number of OFDM symbols is used to determine the transport block size at least in part based on an indication that identifies whether one or more OFDM symbols configured to provide feedback transmission in one or more time slots are to be included or excluded when determining the transport block size.

[0156] Example 18 is a system that includes one or more processors and a memory in electronic communication with the one or more processors, the memory storing instructions executable by the one or more processors to cause the system or device to implement the method of any of Examples 1 - 17.

[0157] Example 19 is a device that includes means for implementing the method or device of any of Examples 1 - 17.

[0158] Example 20 is a non - transient computer - readable medium storing instructions that are executable by one or more processors to cause the one or more processors to implement the method of any of Examples 1 - 17.

[0159] Example 21 is a method for wireless communication at a second sidelink communication device, the method including: identifying sidelink data to be transmitted to at least a first sidelink communication device in a sidelink data channel transmission from the second sidelink communication device, determining the transport block size for the sidelink data channel transmission at least in part based on the time - slot format of one or more time slots reserved for transmitting the sidelink data channel transmission, transmitting sidelink control information to the first sidelink communication device indicating the time - slot format for determining the transport block size for the sidelink data channel transmission, and transmitting the sidelink data channel transmission to the first sidelink communication device, wherein the sidelink data is encoded in the sidelink data channel transmission according to the determined transport block size.

[0160] In Example 22, the method of Example 21 may include, wherein the indication in the sidelink control information indicates at least whether a first time slot format or a second time slot format is used to determine the transport block size.

[0161] In Example 23, the method of Examples 21-22 may include, wherein the first time slot format includes a first number of orthogonal frequency division multiplexing (OFDM) symbols available for shared channel transmission, and the second time slot format includes a second number of OFDM symbols less than the first number of OFDM symbols available for shared channel transmission.

[0162] In Example 24, the method of Examples 21-23 may include, wherein the indication in the sidelink control information is an explicit indication as to whether feedback channel resources within a transmission time slot are to be used to determine the transport block size at a first sidelink communication device.

[0163] In Example 25, the method of Example 24 may include, wherein the explicit indication includes one or more bits in the sidelink control information indicating whether the feedback channel resources are included or excluded in determining the transport block size.

[0164] In Example 26, the method of Examples 24-25 may include, wherein the explicit indication is provided in first-phase sidelink control information transmitted in sidelink control channel communication, in second-phase sidelink control information multiplexed with sidelink data in sidelink shared channel communication, or a combination thereof.

[0165] In Example 27, the method of Examples 24-26 may include, wherein when a time slot for initial sidelink data channel transmission includes feedback channel resources, the feedback channel resources are excluded in determining the transport block size, and when a time slot for initial sidelink data channel transmission does not include feedback channel resources, the feedback channel resources are included in determining the transport block size.

[0166] In Example 28, the method of Examples 24-27 may include, wherein when at least one time slot having resources reserved for sidelink data channel transmission includes feedback channel resources, the feedback channel resources are excluded in determining the transport block size, and when all time slots having resources reserved for sidelink data channel transmission do not include feedback channel resources, the feedback channel resources are included in determining the transport block size.

[0167] In Example 29, the method of Examples 21-23 may include, wherein the indication in the sidelink control information is an implicit indication as to whether feedback channel resources within a transmission time slot are to be used to determine the transport block size.

[0168] In Example 30, the method of Example 29 may include, wherein the implicit indication is based on the MCS used for sidelink data transmission.

[0169] In Example 31, the method of Example 30 may include that when the code rate of the MCS exceeds the code rate threshold, the feedback channel resource is excluded when determining the transport block size, and when the code rate is at or below the code rate threshold, the feedback channel resource is included when determining the transport block size.

[0170] In Example 32, the method of Examples 30-31 may include that when the MCS index provided in the sidelink control information exceeds the MCS index threshold, the feedback channel resource is excluded when determining the transport block size, and when the MCS index is at or below the MCS index threshold, the feedback channel resource is included when determining the transport block size.

[0171] In Example 33, the method of Examples 30-32 may include that when the modulation order of the MCS exceeds the modulation order threshold, the feedback channel resource is excluded when determining the transport block size, and when the modulation order is at or below the modulation order threshold, the feedback channel resource is included when determining the transport block size.

[0172] In Example 34, the method of Examples 30-33 may include that when the MCS index provided in the sidelink control information is within a predetermined set of MCS index values, the feedback channel resource is excluded when determining the transport block size, and when the MCS index is outside the predetermined set of MCS index values, the feedback channel resource is included when determining the transport block size.

[0173] In Example 35, the method of Example 29 may include that the implicit indication is based on one or more values of one or more parameters of the sidelink grant for sidelink data channel transmission provided by the sidelink control information.

[0174] In Example 36, the method of Example 35 may include that the one or more parameters include the data priority of the sidelink data channel transmission, and when the data priority exceeds the data priority threshold, the feedback channel resource is excluded when determining the transport block size.

[0175] In Example 37, the method of Examples 35-36 may include that the one or more parameters indicate that the sidelink data channel transmission is a unicast transmission, a multicast transmission, or a broadcast transmission, and when the sidelink data channel transmission is a multicast transmission or a broadcast transmission, the feedback channel resource is excluded when determining the transport block size.

[0176] In Example 38, the method of Examples 21-37 may include that determining the transport block size includes determining the number of OFDM symbols in one or more time slots reserved for sidelink data channel transmission based on the time slot format, and determining the transport block size at least in part based on the number of OFDM symbols.

[0177] In Example 39, the method of Example 38 may include, where a first value or a second value of the number of OFDM symbols is used to determine a transport block size based at least in part on whether one or more OFDM symbols configured to provide a feedback transmission in one or more time slots are included or excluded when determining the transport block size.

[0178] Example 40 is a system that includes one or more processors and a memory in electronic communication with the one or more processors, the memory storing instructions executable by the one or more processors to cause the system or device to implement the method of any of Examples 21 - 39.

[0179] Example 41 is a device that includes means for implementing the method or device of any of Examples 21 - 39.

[0180] Example 42 is a non - transient computer - readable medium storing instructions executable by one or more processors to cause the one or more processors to implement the method of any of Examples 21 - 39.

[0181] Although aspects of LTE, LTE - A, LTE - A Pro, or NR systems may be described for example purposes and the terms LTE, LTE - A, LTE - A Pro, or NR may be used in most of the description, the techniques described herein may also be applied to networks other than LTE, LTE - A, LTE - A Pro, or NR networks. For example, the described techniques may be applied to various other wireless communication systems such as Ultra Mobile Broadband (UMB), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi - Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash - OFDM, and other systems and radio technologies not explicitly mentioned herein.

[0182] The information and signals described herein may be represented using any of a variety of different arts and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout this description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or optical particles, or any combination thereof.

[0183] The various illustrative blocks and components described in connection with the disclosure herein can be implemented or performed with a general purpose processor, a DSP, an ASIC, a CPU, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0184] The functions described herein can be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions can be stored on or transmitted via a computer-readable medium as one or more instructions or code. Other examples and implementations fall within the scope of the present disclosure and the appended claims. For example, due to the nature of software, the functions described herein can be implemented using software, hardware, firmware, hardwired, or any combination thereof executed by a processor. The features implementing the functions can also be physically located in various places, including being distributed such that portions of the functions are implemented at different physical locations.

[0185] Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. Non-transitory storage media can be any available media that can be accessed by a general or special purpose computer. By way of example and not limitation, non-transitory computer-readable media may include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, compact disc (CD) ROM or other optical disc storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a general or special purpose computer, or a general or special purpose processor. Similarly, any connection is properly termed a computer-readable medium. For example, if software is transmitted from a web site, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of computer-readable medium. As used herein, disk and disc include CD, laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Blu-ray disc, where disks typically reproduce data magnetically and discs reproduce data optically with lasers. Combinations of the above media are also included within the scope of computer-readable media.

[0186] As used herein, including in the claims, the "or" used in a list of items (e.g., a list of items accompanied by language such as "at least one of" or "one or more of") indicates an inclusive listing such that, for example, the listing of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Similarly, as used herein, the phrase "based on" should not be construed as reciting a closed set of conditions. For example, an example step described as "based on condition A" may be based on both condition A and condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "at least partially based on".

[0187] In the drawings, like components or features may have the same reference numerals. Additionally, each of the same type of components may be distinguished by following the reference numeral with a dash and a second label that differentiates between similar components. If only the first reference numeral is used in the specification, the description may apply to any one of the similar components having the same first reference numeral regardless of the second reference numeral, or any other subsequent reference numerals.

[0188] The description set forth herein in connection with the drawings describes example configurations and does not represent all examples that may be implemented or that fall within the scope of the claims. The term "example" as used herein means "serving as an example, instance, or illustration" and does not mean "superior to" or "better than" other examples. This detailed description includes specific details to provide an understanding of the described techniques. However, the techniques may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described examples.

[0189] The description provided herein is to enable a person of ordinary skill in the art to make or use the present disclosure. Various modifications to the present disclosure will be apparent to a person of ordinary skill in the art, and the general principles defined herein may be applied to other variations without departing from the scope of the present disclosure. Thus, the present disclosure is not limited to the examples and designs described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for wireless communication at a transmitting sidelink communication device, comprising: determining a transport block size for sidelink data channel transmission to at least a first sidelink communication device, the transport block size being at least partially based on a first time slot format or a second time slot format of one or more time slots reserved for transmitting the sidelink data channel transmission; transmitting to the first sidelink communication device sidelink control information providing an indication that the first time slot format or the second time slot format is to be used for determining the transport block size of the sidelink data channel transmission; and transmitting the sidelink data channel transmission to the first sidelink communication device, wherein the sidelink data is encoded in the sidelink data channel transmission according to the determined transport block size.

2. The method according to claim 1, wherein the first time slot format includes a first number of orthogonal frequency division multiplexing (OFDM) symbols available for shared channel transmission, and the second time slot format includes a second number of OFDM symbols less than the first number of OFDM symbols available for shared channel transmission to accommodate physical sidelink feedback channel resources in the second time slot format.

3. The method according to claim 1, wherein the indication in the sidelink control information is an explicit indication as to whether physical sidelink feedback channel resources within a transmission time slot are to be included or excluded at the first sidelink communication device to determine the transport block size.

4. The method according to claim 3, wherein the explicit indication includes one or more bits in the sidelink control information indicating whether the physical sidelink feedback channel resources are included or excluded in determining the transport block size.

5. The method according to claim 3, wherein the explicit indication is provided in first-phase sidelink control information transmitted in a physical sidelink control channel.

6. The method according to claim 3, wherein a difference of three orthogonal frequency division multiplexing (OFDM) symbols within the transmission time slot is used to determine the transport block size based on whether the physical sidelink feedback channel resources are included or excluded at the first sidelink communication device to determine the transport block size.

7. The method according to claim 3, wherein when a time slot for an initial sidelink data channel transmission includes physical sidelink feedback channel resources, the physical sidelink feedback channel resources are excluded in determining the transport block size, and when the time slot for the initial sidelink data channel transmission does not include physical sidelink feedback channel resources, the physical sidelink feedback channel resources are included in determining the transport block size.

8. The method according to claim 3, wherein when at least one time slot having resources reserved for sidelink data channel transmission includes physical sidelink feedback channel resources, the physical sidelink feedback channel resources are excluded when determining the transport block size, and when all time slots having resources reserved for the sidelink data channel transmission do not include physical sidelink feedback channel resources, the physical sidelink feedback channel resources are included when determining the transport block size.

9. The method according to claim 1, wherein the indication in the sidelink control information is an implicit indication as to whether the physical sidelink feedback channel resources within the transmission time slot are to be excluded when determining the transport block size.

10. The method according to claim 9, wherein the implicit indication is based on a modulation and coding scheme (MCS) for the sidelink data transmission.

11. The method according to claim 10, wherein when the code rate of the MCS exceeds a code rate threshold, the physical sidelink feedback channel resources are excluded when determining the transport block size, and when the code rate is at or below the code rate threshold, the physical sidelink feedback channel resources are included when determining the transport block size.

12. The method according to claim 10, wherein when the MCS index provided in the sidelink control information exceeds an MCS index threshold, the physical sidelink feedback channel resources are excluded when determining the transport block size, and when the MCS index is at or below the MCS index threshold, the physical sidelink feedback channel resources are included when determining the transport block size.

13. The method according to claim 10, wherein when the modulation order of the MCS exceeds a modulation order threshold, the physical sidelink feedback channel resources are excluded when determining the transport block size, and when the modulation order is at or below the modulation order threshold, the physical sidelink feedback channel resources are included when determining the transport block size.

14. The method according to claim 10, wherein when the MCS index provided in the sidelink control information is within a pre-determined set of MCS index values, the physical sidelink feedback channel resources are excluded when determining the transport block size, and when the MCS index is outside the pre-determined set of MCS index values, the physical sidelink feedback channel resources are included when determining the transport block size.

15. The method according to claim 9, wherein the implicit indication is based on one or more values of one or more parameters of a sidelink grant for the sidelink data channel transmission provided by the sidelink control information.

16. The method according to claim 1, wherein determining the transport block size comprises: determining the number of orthogonal frequency division multiplexing (OFDM) symbols within the one or more time slots reserved for the sidelink data channel transmission based on the first time slot format or the second time slot format; and determining the transport block size at least in part based on the number of OFDM symbols.

17. The method according to claim 16, wherein a first value or a second value of the number of the OFDM symbols is used to determine the transport block size at least in part based on whether one or more OFDM symbols configured to provide feedback transmission in one or more time slots are to be included or excluded when determining the transport block size.

18. A method for wireless communication at a first sidelink communication device, comprising: receiving, from a second sidelink communication device, sidelink control information for a sidelink data channel transmission from the second sidelink communication device, the sidelink control message including an indication of a first time slot format or a second time slot format for determining a transport block size of the sidelink data channel transmission; and decoding the sidelink data channel transmission at least in part based on the transport block size of the sidelink data channel transmission, wherein the transport block size is determined at least in part based on the indication in the sidelink control information.

19. The method according to claim 18, wherein the first time slot format includes a first number of orthogonal frequency division multiplexing (OFDM) symbols available for shared channel transmission, and the second time slot format includes a second number of OFDM symbols less than the first number of OFDM symbols available for shared channel transmission to accommodate physical sidelink feedback channel resources in the second time slot format.

20. The method according to claim 18, wherein the indication in the sidelink control information is an explicit indication of whether physical sidelink feedback channel resources within a transmission time slot are to be included or excluded when determining the transport block size.

21. The method according to claim 20, wherein the explicit indication includes one or more bits in the sidelink control information indicating whether the physical sidelink feedback channel resources are to be included or excluded when determining the transport block size.

22. The method according to claim 18, wherein the indication in the sidelink control information is an implicit indication of whether physical sidelink feedback channel resources within a transmission time slot are to be included or excluded when determining the transport block size.

23. The method according to claim 18, further comprising: determining the transport block size at least in part based on the number of orthogonal frequency division multiplexing (OFDM) symbols within a time slot associated with the sidelink data channel transmission, and wherein the number of the OFDM symbols is determined based on the indication in the sidelink control information.

24. The method according to claim 23, wherein a first value or a second value of the number of the OFDM symbols is used to determine the transport block size at least in part based on the indication identifying whether one or more OFDM symbols configured to provide feedback transmission in one or more time slots are to be included or excluded when determining the transport block size.

25. An apparatus for wireless communication at a transmitting sidelink communication device, comprising: Apparatus for determining a transport block size for sidelink data channel transmission to at least a first sidelink communication device, the transport block size being at least partially based on a first time slot format or a second time slot format of one or more time slots reserved for the sidelink data channel transmission; Apparatus for transmitting to the first sidelink communication device sidelink control information providing an indication regarding the transport block size determination for the sidelink data channel transmission to use the first time slot format or the second time slot format; And Apparatus for transmitting the sidelink data channel transmission to the first sidelink communication device, wherein the sidelink data is encoded in the sidelink data channel transmission according to the determined transport block size.

26. The apparatus according to claim 25, wherein the first time slot format includes a first number of orthogonal frequency division multiplexing (OFDM) symbols available for shared channel transmission, and the second time slot format includes a second number of OFDM symbols less than the first number of OFDM symbols available for shared channel transmission to accommodate physical sidelink feedback channel resources in the second time slot format.

27. The apparatus according to claim 25, wherein the indication in the sidelink control information is an explicit indication regarding whether physical sidelink feedback channel resources within a transmission time slot are to be included or excluded at the first sidelink communication device to determine the transport block size.

28. The apparatus according to claim 27, wherein the explicit indication includes one or more bits in the sidelink control information indicating whether the physical sidelink feedback channel resources are included or excluded in determining the transport block size.

29. The apparatus according to claim 27, wherein the explicit indication is provided in first phase sidelink control information transmitted in a physical sidelink control channel.

30. The apparatus according to claim 27, wherein a difference of three orthogonal frequency division multiplexing (OFDM) symbols within the transmission time slot is used to determine the transport block size based on whether the physical sidelink feedback channel resources are included or excluded at the first sidelink communication device to determine the transport block size.

31. The apparatus according to claim 27, wherein when a time slot for an initial sidelink data channel transmission includes physical sidelink feedback channel resources, the physical sidelink feedback channel resources are excluded in determining the transport block size, and when the time slot for the initial sidelink data channel transmission does not include physical sidelink feedback channel resources, the physical sidelink feedback channel resources are included in determining the transport block size.

32. The apparatus according to claim 27, wherein when at least one time slot having resources reserved for sidelink data channel transmission includes physical sidelink feedback channel resources, the physical sidelink feedback channel resources are excluded in determining the transport block size, and when all time slots having resources reserved for the sidelink data channel transmission do not include physical sidelink feedback channel resources, the physical sidelink feedback channel resources are included in determining the transport block size.

33. The device according to claim 25, wherein the indication in the sidelink control information is an implicit indication as to whether the physical sidelink feedback channel resources within a transmission time slot are to be excluded when determining the transmission block size.

34. The device according to claim 33, wherein the implicit indication is based on a modulation and coding scheme (MCS) for the sidelink data transmission.

35. The device according to claim 34, wherein when the code rate of the MCS exceeds a code rate threshold, the physical sidelink feedback channel resources are excluded when determining the transmission block size, and when the code rate is at or below the code rate threshold, the physical sidelink feedback channel resources are included when determining the transmission block size.

36. The device according to claim 34, wherein when the MCS index provided in the sidelink control information exceeds an MCS index threshold, the physical sidelink feedback channel resources are excluded when determining the transmission block size, and when the MCS index is at or below the MCS index threshold, the physical sidelink feedback channel resources are included when determining the transmission block size.

37. The device according to claim 34, wherein when the modulation order of the MCS exceeds a modulation order threshold, the physical sidelink feedback channel resources are excluded when determining the transmission block size, and when the modulation order is at or below the modulation order threshold, the physical sidelink feedback channel resources are included when determining the transmission block size.

38. The device according to claim 34, wherein when the MCS index provided in the sidelink control information is within a pre-determined set of MCS index values, the physical sidelink feedback channel resources are excluded when determining the transmission block size, and when the MCS index is outside the pre-determined set of MCS index values, the physical sidelink feedback channel resources are included when determining the transmission block size.

39. The device according to claim 33, wherein the implicit indication is based on one or more values of one or more parameters of a sidelink grant for the sidelink data channel transmission provided by the sidelink control information.

40. The device according to claim 25, wherein the number of orthogonal frequency division multiplexing (OFDM) symbols within the one or more time slots reserved for the sidelink data channel transmission is determined based on the first time slot format or the second time slot format, and the transmission block size is determined at least in part based on the number of OFDM symbols.

41. The device according to claim 40, wherein a first value or a second value of the number of OFDM symbols is used to determine the transmission block size at least in part based on whether one or more OFDM symbols configured to provide feedback transmission in the one or more time slots are to be included or excluded when determining the transmission block size.

42. A device for wireless communication at a first sidelink communication device comprising: Apparatus for receiving sidelink control information for sidelink data channel transmission from a second sidelink communication device, the sidelink control message including an indication of a first time slot format or a second time slot format for determining a transport block size of the sidelink data channel transmission; And Apparatus for decoding the sidelink data channel transmission at least in part based on the transport block size of the sidelink data channel transmission, wherein the transport block size is determined at least in part based on the indication in the sidelink control information.

43. The apparatus according to claim 42, wherein the first time slot format includes a first number of orthogonal frequency division multiplexing (OFDM) symbols available for shared channel transmission, and the second time slot format includes a second number of OFDM symbols less than the first number of OFDM symbols available for shared channel transmission to accommodate physical sidelink feedback channel resources in the second time slot format.

44. The apparatus according to claim 42, wherein the indication in the sidelink control information is an explicit indication as to whether physical sidelink feedback channel resources within a transmission time slot are to be used to determine the transport block size.

45. The apparatus according to claim 44, wherein the explicit indication includes one or more bits in the sidelink control information indicating whether the physical sidelink feedback channel resources are to be included or excluded in determining the transport block size.

46. The apparatus according to claim 42, wherein the indication in the sidelink control information is an implicit indication as to whether physical sidelink feedback channel resources within a transmission time slot are to be included or excluded in determining the transport block size.

47. The apparatus according to claim 42, further Comprising: Apparatus for determining the transport block size at least in part based on the number of orthogonal frequency division multiplexing (OFDM) symbols associated with the sidelink data channel transmission within a time slot, and wherein the number of OFDM symbols is determined based on the indication in the sidelink control information.

48. The apparatus according to claim 47, wherein a first value or a second value of the number of OFDM symbols is used to determine the transport block size at least in part based on the indication identifying whether one or more OFDM symbols configured to provide feedback transmission in one or more time slots are to be included or excluded in determining the transport block size.

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