Transport Block Size Determination for Two-Stage Control

Abstract

Methods, systems, and devices for wireless communication are described. In some systems, two devices may communicate on a sidelink and support a mutually understood transport block (TB) size (TBS) determination procedure associated with a data channel that includes control messages. A first device may encode and transmit information including control messages and data messages on the data channel. A second device may receive and decode the information on the data channel. The first device and the second device may determine the TBS for encoding and decoding the data channel based on determining an estimated resource element (RE) overhead for the control message and determining an approximate TBS based on the estimated RE overhead, respectively.

Description

[0001] Cross-reference

[0002] This patent application claims the benefit of U.S. Provisional Patent Application No. 62 / 975,914, entitled "TRANSPORT BLOCKSIZE DETERMINATION FOR TWO STAGE CONTROL," filed on February 13, 2020 by SARKIS et al., and U.S. Patent Application No. 17 / 156,177, entitled "TRANSPORT BLOCK SIZE DETERMINATION FOR TWO STAGE CONTROL," filed on January 22, 2021 by SARKIS et al., each of which is assigned to the assignee of the present application. Technical Field

[0003] The following generally relates to wireless communication and includes determination of transport block (TB) size (TBS) for two-stage control.

[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 the like. These systems may be capable of supporting communication with multiple users by sharing available system resources (e.g., 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 that 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 supports communication of multiple communication devices simultaneously, and these communication devices may be otherwise referred to as user equipment (UE).

[0006] A first device (such as, a UE or a base station) may schedule communication with a second device by transmitting control information to the second device. In some cases, the first device may transmit control information or a portion of control information in a data channel, and the control information may schedule a data message that is also transmitted in the data channel. Current techniques for decoding control information and data messages in a data channel may be inefficient and may result in communication failures in some cases.

[0007] Overview

[0008] The described technology relates to improved methods, systems, devices, or apparatuses that support transport block (TB) size (TBS) determination for two-stage control. Generally, the described technology provides accurate TBS determination of a TB associated with a data channel (e.g., a physical sidelink shared channel (PSSCH)) when there is a control message in the data channel. For example, a first device may communicate with a second device and may transmit a control message to the second device in the data channel, where the control message provides information for decoding a data message also transmitted in the data channel. In some aspects, the control message and the data message may each occupy several resource elements (REs) of the data channel, and the first device may encode the data channel (or one or both of the control message and the data message) based on the TBS associated with the data channel. In some cases, for the second device to successfully decode the data channel (or one or both of the control message and the data message), the second device may use the same code rate as the first device used to encode the data channel to decode the data channel. Thus, some implementations of the present disclosure may implement a mutually understood or shared procedure between the first device and the first device such that the first device and the first device can determine the same TBS to be used to determine the code rate that can be used to encode or decode the data channel.

[0009] In some implementations, the first device and the second device may determine a first RE overhead, which may be an approximation or estimate of the actual number of REs occupied by the control message in the data channel. The first device and the second device may determine a first TBS associated with the data channel based on the determined first RE overhead. The first TBS may also be an approximation or estimate of the actual TBS associated with the data channel. The first TBS may be an intermediate TBS that the first device and the second device can use for actual TBS determination or code rate calculation. In some examples, the first device and the second device may generally use the first RE overhead and the first TBS (e.g., approximations) to encode or decode the channel. In such examples, the first device may encode the data channel (one or both of the control message and the data message) with a code rate based on the first TBS. Similarly, the second device may decode the data channel (one or both of the control message and the data message) with a code rate based on the first TBS.

[0010] Alternatively, in some other examples, and based on similarly determining the first RE overhead and the first TBS, the first device and the second device may share an intermediate TBS that is mutually understood by both devices and can be used to determine the actual RE overhead and the actual TBS, which may result in the first device and the second device respectively determining to use a similar (or the same) code rate for encoding and decoding. Accordingly, in some implementations, both the first device and the second device may use the intermediate TBS (e.g., the first TBS) to calculate the actual number of modulation symbols or REs occupied by the control message in the data channel. The first device and the second device may use the actual number of REs in the control message or the indicated number of REs in the control information to determine the actual TBS associated with the data channel. The first device may encode the data channel with a code rate based on the actual TBS determined from the intermediate TBS. Similarly, the second device may decode the data channel with a code rate based on the actual TBS determined similarly from the intermediate TBS. Brief Description of the Drawings

[0012] Figure 1 and 2 illustrates examples of wireless communication systems supporting transport block (TB) size (TBS) determination for two-stage control in accordance with aspects of the present disclosure.

[0013] Figure 3 and 4 illustrates examples of process flows supporting TBS determination for two-stage control in accordance with aspects of the present disclosure.

[0014] Figure 5 and 6 illustrates a block diagram of a device supporting TBS determination for two-stage control in accordance with aspects of the present disclosure.

[0015] Figure 7 illustrates a block diagram of a communication manager supporting TBS determination for two-stage control in accordance with aspects of the present disclosure.

[0016] Figure 8 illustrates a diagram of a system including a device supporting TBS determination for two-stage control in accordance with aspects of the present disclosure.

[0017] Figures 9 to 14 shows a flowchart illustrating support for TBS determination for two-stage control in accordance with aspects of the present disclosure.

[0018] Detailed Description

[0019] As the demand for communication resources increases due to the increasing number of wireless devices communicating on the available spectrum, techniques for efficiently and reliably increasing throughput are desired. In some cases, a first device may transmit a control message to a second device in a communication channel (e.g., a data channel), where the control message may indicate information for decoding a data message in the same communication channel. For example, the first device may implement a two-stage control transmission, where a first portion of the control information is transmitted in a control channel and a second portion of the control information is transmitted in the data channel. This communication may be associated with reduced latency and greater throughput and may more efficiently utilize resources in the available spectrum. In some examples, the first device and the second device may be examples of user equipment (UE) communicating via a sidelink (e.g., the first device and the second device may be associated with a vehicle-to-everything (V2X) system or another system supporting sidelink communication). In such examples, the first device may transmit a control message and a data message to the second device in a data channel (such as a physical sidelink shared channel (PSSCH)). If the control message is part of a two-stage control transmission, the first device may transmit first-stage sidelink control information (SCI1) in a physical sidelink control channel (PSCCH) and may transmit the control message, which may be an example of second-stage sidelink control information (SCII), in the PSSCH).

[0020] In some cases, the control message may consume a relatively significant portion of the PSSCH (e.g., due to the payload size of the control message). As such, in the transport block (TB) size (TBS) calculation, the resource element (RE) overhead associated with the control message in the data channel may not be ignored without creating a significant mismatch between the code rate used by the first device for encoding the data channel and the code rate used by the second device for decoding the data channel. This mismatch may result in a communication failure as the second device may not be able to successfully decode the TB in the data channel.

[0021] Various implementations of the present disclosure generally relate to efficient and consistent TBS and code rate determination procedures across one or more wireless devices. In some particular implementations, a first device and a second device (e.g., UEs communicating on a sidelink channel using a two-stage control procedure) may adopt the same TBS determination procedure such that both the first device and the second device determine the same code rate based on the same determined TBS. For example, the first device may determine an approximation of the number of REs associated with a control message (e.g., SCI2 transmitted in a data channel), which may be referred to as the estimated RE overhead or the first RE overhead. The first device may use the estimated RE overhead to determine an approximation of the TBS, which may be referred to as the first TBS or the intermediate TBS. Similarly, the second device may determine the estimated RE overhead and determine the first TBS based on the estimated RE overhead. Thus, the first device and the second device may determine the same first TBS, and the first device and the second device may use the first TBS to determine the number of modulation symbols for the control message. The first device may encode the control message according to the number of modulation symbols, while the second device may decode the control message according to the number of modulation symbols, thereby supporting reliable transmission of the control message. In some examples, the first device and the second device may determine the actual TBS for the data channel based on the intermediate TBS (e.g., based on the number of modulation symbols or REs of the control message in the data channel). The first device and the second device may use the actual TBS to determine the same code rate for encoding and decoding data in the data channel. Alternatively, in some other examples, the first device and the second device may use an approximate TBS to determine the same code rate for encoding and decoding data (such as a data message) in the data channel.

[0022] In some cases, the first and second devices may determine the same estimated RE overhead for a control message (e.g., SCI2 in PSSCH) based on the devices using a preconfigured value for the estimated RE overhead. In some other cases, the first device may indicate the estimated RE overhead in a control message (e.g., SCI1 in PSCCH) transmitted in the control channel. The estimated RE overhead may be defined per physical resource block (PRB) or per channel (e.g., per PSSCH). The device may use the estimated RE overhead to determine the intermediate TBS and modulation symbols for the control message. Further, the device may determine the number of REs available for data transmission in the data channel based on the control message. For example, the device may account for the RE overhead of the control message in the data channel by subtracting the actual number of REs for the control message (e.g., based on the determined number of modulation symbols), subtracting the number of REs signaled in the control message (e.g., and dynamically configured by the first device), or subtracting some combination thereof. The device may determine the actual TBS for the data channel based on accounting for the RE overhead of the control message.

[0023] Certain aspects of the subject matter described herein can be implemented to achieve one or more potential advantages. The described techniques can support more efficient and consistent TBS determination between two wireless devices that communicate control information for a data channel over the data channel, which can lead to a greater likelihood of successful decoding operations at the receiving device, as well as a corresponding reduced latency for communication over the data channel (e.g., for sidelink communication over the PSSCH). This improved transmission reliability can result in fewer retransmission operations by the wireless devices, thereby reducing signaling overhead on the channel. Further, the two wireless devices can achieve power savings by reducing the number of sidelink retransmissions (e.g., for SCI2, sidelink data messages, or both). The wireless devices can also achieve a more robust communication link based on consistent and common TBS determination, which can lead to higher data rates, greater wireless communication capacity, and improved spectral efficiency.

[0024] Aspects of the present disclosure are initially described in the context of a wireless communication system. Additional aspects are described with respect to process flows. Aspects of the present disclosure are further illustrated and described by and with reference to apparatus diagrams, system diagrams, and additional flowcharts related to transmission block size determination for two-stage control.

[0025] Figure 1 An example of a wireless communication system 100 that supports TBS determination for two-stage control 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 LTE-Advanced (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.

[0026] 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 having 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 geographic 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 geographic 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.

[0027] Each UE 115 may be dispersed throughout the geographic 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 in

[0028] 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.

[0029] 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.

[0030] 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, vehicles, meters, etc.

[0031] 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 1as shown in

[0032] 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 of a radio frequency spectrum band (e.g., a bandwidth part (BWP)) 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.

[0033] In some examples (e.g., in a carrier aggregation configuration), a carrier may also have acquisition signaling or control signaling for coordinating the operation of other carriers. A carrier may be associated with a frequency channel (e.g., an evolved universal mobile telecommunications system terrestrial radio access (E-UTRA) absolute radio frequency channel number (EARFCN)) and may be located according to a channel raster for discovery by UE 115. A carrier may operate in a stand-alone mode in which initial acquisition and connection may be performed by UE 115 via the carrier, or a carrier may operate in a non-stand-alone mode in which the connection is anchored using a different carrier (e.g., a different carrier of the same or different radio access technology).

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

[0036] The signal waveform transmitted on a carrier can include multiple subcarriers (e.g., using a multi-carrier modulation (MCM) technique such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)). In a system that employs an MCM technique, a resource element can 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 can 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 can 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 communication with the UE 115.

[0037] One or more parameter sets can be supported for a carrier, where a parameter set can include a subcarrier spacing (Δf) and a cyclic prefix. A carrier can be divided into one or more BWPs with the same or different parameter sets. In some examples, the UE 115 can be configured with multiple BWPs. In some examples, a single BWP for a carrier can be active at a given time, and communication for the UE 115 can be limited to one or more active BWPs.

[0038] The time intervals of the base station 105 or the UE 115 can be expressed as multiples of a basic time unit, which can refer to, for example, a sampling period T s = 1 / (Δf max ·Nf) seconds, where Δf maxmay represent the maximum supported subcarrier spacing, and Nf may represent the maximum supported discrete Fourier transform (DFT) size. A time interval of 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).

[0039] Each frame may include a plurality of 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 a number of 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 a number of 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 a plurality of mini time slots each including one or more symbols. Excluding the cyclic prefix, each symbol period may include one or more (e.g., Nf) sampling periods. The duration of a symbol period may depend on the subcarrier spacing or the operating frequency band.

[0040] A subframe, a time slot, a mini time slot, or a symbol may be the smallest scheduling unit (e.g., in the time domain) of the wireless communication system 100 and may be referred to as a transmission time interval (TTI). In some examples, the TTI duration (e.g., the number of symbol periods in a TTI) may be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communication system 100 may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs)).

[0041] 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, one or more of time division multiplexing (TDM) techniques, frequency division multiplexing (FDM) techniques, or hybrid TDM-FDM techniques. A control region for the physical control channel (e.g., a control resource set (CORESET)) can be defined by a 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 with a given payload size. The search space set can include a common search space set configured to send control information to a plurality of UEs 115 and a UE-specific search space set for sending control information to a specific UE 115.

[0042] 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 geographic coverage area 110 or a portion of the geographic coverage area 110 (e.g., a sector) on which the logical communication entity operates. The scope of such cells can vary depending on various factors (such as the capabilities of the base station 105) from a smaller area (e.g., a structure, a subset of a structure) to a larger area. For example, a cell can be or include a building, a subset of a building, or an external space between or overlapping with the geographic coverage area 110, and other examples.

[0043] Macro cells generally cover a relatively large geographical area (e.g., with a radius of several kilometers) and may allow unconstrained access by UEs 115 having a service subscription with the network provider that supports 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.

[0044] 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 for different types of devices (e.g., MTC, narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB)).

[0045] 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. 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.

[0046] Wireless communication system 100 may support synchronous or asynchronous operation. For synchronous operation, base stations 105 may have similar frame timings, and transmissions from different base stations 105 may be approximately aligned in time. For asynchronous operation, base stations 105 may have different frame timings, and in some examples, transmissions from different base stations 105 may not be aligned in time. The techniques described herein may be used for synchronous or asynchronous operation.

[0047] 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 a device to communicate with the 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, wilderness survival monitoring, weather and geographical event monitoring, queue management and tracking, remote security sensing, physical access control, and transaction-based commercial charging.

[0048] 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 (e.g., a set of subcarriers or resource blocks (RBs)) within a carrier, within a guard band of a carrier, or outside a carrier.

[0049] 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. The 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.

[0050] 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 be unable to receive transmissions from base station 105 for other reasons. 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.

[0051] 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 a roadside unit), or with a network, or with both, using vehicle-to-network (V2N) communication via one or more network nodes (e.g., base station 105).

[0052] 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 (e.g., a mobility management entity (MME), an access and mobility management function (AMF)) that manages access and mobility, and at least one user plane entity (e.g., a serving gateway (S-GW), a packet data network (PDN) gateway (P-GW), or a user plane function (UPF)) that routes packets or interconnects to external networks. The control plane entity may manage non-access stratum (NAS) functions such as the mobility, authentication, and bearer management of UE 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.

[0053] 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 respective UEs 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, the 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).

[0054] Wireless communication system 100 may operate using one or more frequency bands, sometimes 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).

[0055] 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, wireless communication system 100 may support millimeter wave (mmW) communication between UEs 115 and 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.

[0056] The wireless communication system 100 can utilize both licensed and unlicensed radio frequency bands. For example, the wireless communication system 100 can adopt licensed-assisted access (LAA), LTE-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 adopt carrier sensing for collision detection and avoidance. In some examples, the 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. The operation in the unlicensed spectrum can include downlink transmission, uplink transmission, P2P transmission, or D2D transmission, etc.

[0057] Base station 105 or UE 115 can be equipped with multiple antennas, which can be used to adopt 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, the antenna panel can support radio frequency beamforming for signals transmitted via the antenna ports.

[0058] 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, the transmitting device can transmit multiple signals via different antennas or different combinations of antennas. Similarly, the 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.

[0059] 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. The adjustment of 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 adjustment 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).

[0060] The base station 105 or the UE 115 can use beam sweeping techniques as part of a beamforming operation. For example, the base station 105 can use multiple antennas or antenna arrays (e.g., antenna panels) to perform beamforming operations for directional communication with the UE 115. Some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) can be transmitted by the base station 105 multiple times in different directions. For example, the base station 105 can transmit signals according to different sets of beamforming weights associated with different transmission directions. Transmissions in different beam directions can be used (e.g., by the transmitting device such as the base station 105 or the receiving device such as the UE 115) to identify the beam direction used by the base station 105 for later transmission or reception.

[0061] Some signals (such as data signals associated with a particular receiving device) can be transmitted by the base station 105 in a single beam direction (e.g., the direction associated with the receiving device such as the UE 115). In some examples, the beam direction associated with a transmission in a single beam direction can be determined based on signals transmitted in one or more beam directions. For example, the UE 115 can receive one or more signals transmitted by the base station 105 in different directions and can report an indication to the base station 105 of the signal received by the UE 115 with the highest signal quality or other acceptable signal quality.

[0062] In some examples, transmissions performed by a device (e.g., by base station 105 or UE 115) may be carried out using multiple beam directions, and the device may use a combination of digital precoding or radio frequency beamforming to generate a combined beam for transmission (e.g., from base station 105 to UE 115). UE 115 may report feedback indicating precoding weights for one or more beam directions, and the feedback may correspond to a configured number of beams across the system bandwidth or one or more subbands. Base station 105 may transmit reference signals that may be precoded or uncoded (e.g., cell-specific reference signal (CRS), channel state information reference signal (CSI-RS)). UE 115 may provide feedback for beam selection, which may be a precoding matrix indicator (PMI) or codebook-based feedback (e.g., multi-panel type codebook, linear combination type codebook, port selection type codebook). Although these techniques are described with reference to signals transmitted by base station 105 in one or more directions, UE 115 may use similar techniques for transmitting signals multiple times in different directions (e.g., for identifying beam directions used by UE 115 for subsequent transmissions or receptions) or for transmitting signals in a single direction (e.g., for transmitting data to a receiving device).

[0063] A receiving device (e.g., UE 115) may attempt multiple receive configurations (e.g., directional listening) when receiving various signals from base station 105, such as synchronization signals, reference signals, beam selection signals, or other control signals. For example, the receiving device may attempt multiple receive directions by: receiving via different antenna subarrays, processing received signals according to different antenna subarrays, receiving according to different sets of receive beamforming weights (e.g., different directional listening weight sets) applied to signals received at multiple antenna elements of an antenna array, or processing received signals according to different sets of receive beamforming weights applied to signals received at multiple antenna elements of an antenna array, any of which may be referred to as "listening" according to different receive configurations or receive directions. In some examples, the receiving device may use a single receive configuration to receive along a single beam direction (e.g., when receiving a data signal). The single receive configuration may be aligned in a beam direction determined based on listening according to different receive configuration directions (e.g., a beam direction determined to have the highest signal strength, highest signal-to-noise ratio (SNR), or other acceptable signal quality based on listening according to multiple beam directions).

[0064] The wireless communication system 100 can be a packet-based network that operates according to a hierarchical 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 Medium 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 the RRC connection that supports the radio bearers for user plane data between the UE 115 and the base station 105 or the core network 130. At the physical layer, the transport channels can be mapped to physical channels.

[0065] The UE 115 and the 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 the 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, the device can support simultaneous slot HARQ feedback, where the device can provide HARQ feedback for data received in previous symbols in a particular slot in that slot. In other cases, the device can provide HARQ feedback in a subsequent slot or according to some other time interval.

[0066] In some implementations, a first device (e.g., a first UE 115) may communicate with a second device (e.g., a second UE 115) via a communication link (e.g., a D2D communication link 135, which may be referred to herein as a sidelink). In some examples, the first device may transmit a control message to the second device via the communication link in a communication channel (such as a data channel). For example, the first device and the second device may communicate over the D2D communication link 135 (e.g., a sidelink), and the first device may transmit the control message on the PSSCH. In some aspects, the first device may generate a control message that schedules data messages for transmission in the same channel (e.g., in the same resource set) in which the control message is transmitted or otherwise indicates information for decoding the data message. For example, the first device may transmit a control message in a data channel (e.g., the PSSCH), and the control message may include control information for receiving data messages that are also transmitted in the data channel. In some examples, the first device (e.g., the first UE 115) may determine an estimated (e.g., approximate) RE overhead associated with the control message and may use the estimated RE overhead to encode one or both of the control message or the data message based on the TBS determination procedure. In some cases, the estimated RE overhead may correspond to the estimated number of REs occupied by the control message in the data channel or a preconfigured approximation of the number of REs occupied by the control message in the data channel.

[0067] The second device (e.g., the second UE 115) may receive the encoded control message and may determine the estimated (e.g., approximate) RE overhead. In some aspects, the second device may determine the same estimated RE overhead as the first device (e.g., based on signaling from the first device or preconfiguration). The second device may use the estimated RE overhead to decode one or both of the control message or the data message based on the TBS determination procedure. Additionally, in some examples and based on decoding the control message, the second device may determine the actual TBS and code rate used by the first device for data messages on the data channel. Thus, the first device and the second device may use similar TBS determination procedures such that both the first device and the first device use similar (or the same) code rates for encoding and decoding information in the data channel.

[0068] Figure 2 An example of a wireless communication system 200 that supports TBS determination for two-stage control 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 cases, the wireless communication system 200 may include UEs 115-a and 115-b, which may be as described with reference to Figure 1An example of the UE 115 is described. However, the techniques described herein may be implemented by any wireless device that communicates control information for decoding a communication channel over the communication channel.

[0069] In some examples, both UE 115-a and UE 115-b may support sidelink communication capabilities and may communicate using sidelink 205. In some cases, sidelink 205 may be an example of a D2D link, a relay link, a private network link, an industrial IoT communication link, or any other similar communication link over which peer devices may communicate. In some examples, the wireless communication system 200 may be configured to support mutually understood procedures for TBS determination to increase the likelihood of successful communication within the wireless communication system 200.

[0070] In some cases, UE 115-a may communicate with UE 115-b over sidelink 205. UE 115-a may transmit a control message 210 to UE 115-b to schedule a data message (such as data 230) over sidelink 105. In some aspects, UE 115-a and UE 115-b (e.g., two wireless devices in an NR V2X communication system) may support two-stage control transmission, and control message 210 may be an example of a two-stage control message. For example, UE 115-a may transmit a first-stage control message (such as SCI1 215) and a second-stage control message (such as SCI2 225) to UE 115-b, respectively. In some cases, UE 115-a may transmit SCI1 225 over a control channel (such as PSCCH 220) and may transmit SCI2 225 over a data channel (such as PSSCH 235). In some aspects, UE 115 may transmit data 230 multiplexed with SCI2 225 over PSSCH 235, and in some cases, SCI2 2225 may include control information associated with receiving or decoding data 230.

[0071] Further, although described as a second-stage control message in the context of two-stage control transmission, SCI2 225 may be implemented in other types of control transmission. For example, SCI2 225 may correspond to any control message transmitted over the same channel as a data message, the control message providing control information for the data message (e.g., indicating how to receive or decode the data message).

[0072] SCI1 215 and SCI2 225 may each carry a part of the control information for PSSCH transmission. In some cases, SCI1 215 may indicate resource allocation (e.g., resource allocation for PSSCH 235), the format for SCI2 225, the modulation and coding scheme (MCS) associated with PSSCH 235, or some combination of these or other control information fields. UE 115-a may transmit SCI2 225 in PSSCH235 according to SCI1 215. In some cases, SCI2 2225 may be multiplexed with data 230 in PSSCH 235. SCI2 225 may include a redundant version (RV) of the data 230, an identifier field (e.g., a process identifier field associated with the HARQ process for the data 230), or some combination of these or other control information fields.

[0073] In some aspects, SCI2 225 may be associated with a relatively large payload of information bits (e.g., above a certain payload threshold for PSSCH 235). For example, SCI2 225 may carry a payload greater than 70 bits. In some cases, UE 115-a may modulate SCI2 225 based on the modulation order, where the modulation order refers to or otherwise involves quadrature phase shift keying (QPSK). Based on the relatively large payload of the information bits for SCI2 225 and the QPSK modulation order, SCI2 225 may occupy a significant portion of PSSCH 235 (e.g., greater than a threshold proportion of the REs of PSSCH 235). For example, when QPSK and a code rate of 1 / 4 are implemented, SCI2 225 may be associated with approximately 300 modulation symbols corresponding to an RE overhead of approximately 300 REs in PSSCH 235. This RE overhead may be non-negligible when performing the TBS calculation for PSSCH 235.

[0074] In some cases, UE 115-a may encode SCI2 225 and data 230 in PSSCH 235 based on the code rate (e.g., may encode PSSCH235), and may transmit the encoded SCI2 255 and the encoded data 230 to UE 115-b on PSSCH 235. Additionally, in some cases, UE 115-a may transmit an indication of the code rate to UE 115-b. In some examples, UE 115-a may transmit an indication of the code rate to UE 115-b in the MCS field in SCI1 215.

[0075] UE 115-b can receive the encoded SCI2 225 and the encoded data 230 on the PSSCH 235, and can attempt to decode the encoded SCI2 225 and the encoded data 230. In some examples, UE 115-b can determine the code rate based on the TBS associated with the number of available REs of the PSSCH 235, the MCS indicated in the SCI1 215, or a combination thereof. In some cases, the SCI2 225 can occupy a part of the PSSCH 235 that is below the threshold part (e.g., the number of REs of the PSSCH 235), and the UE 115-a can use a code rate that is sufficiently similar to the code rate indicated to the UE 115-b in the MCS. Accordingly, the UE 115-b can successfully decode the encoded SCI2 225 and the encoded data 230 (e.g., can successfully decode the encoded PSSCH235).

[0076] However, in some other cases, the SCI2 225 can occupy a part of the PSSCH 235 that is above the threshold part, such that the number of REs occupied by the SCI2 255 has a non-negligible impact on the TBS calculation. This can sufficiently change the TBS of the PSSCH 235 such that the UE 115-a uses a code rate that is sufficiently different (e.g., higher) from the code rate indicated to the UE 115-b in the MCS. For example, the code rate determined based on the TBS and the code rate indicated by the MCS may differ by more than a threshold amount. In such cases, the UE115-b may not be able to successfully decode the encoded SCI2 225 and the encoded data 230.

[0077] For example, the UE 115-a can use the TBS to encode the data 230 without considering or being aware of the number of REs occupied by the SCI2 225. Thus, when the part of the PSSCH 235 occupied by the SCI2 255 becomes large enough, the SCI2 225 can sufficiently affect the TBS associated with the PSSCH 235 such that the UE 115-b can determine to use a code rate different from the code rate used by the UE 115-a to encode the data 230.

[0078] To maintain the similarity between the code rate determined by the UE 115 (either one or both of the UE 115-a and UE 115-b) based on the TBS and the code rate indicated in the MCS, the UE 115 can exclude the number of REs occupied by the SCI2 225 when determining the TBS. For example, the UE 115 can attempt to determine the number of REs occupied by the SCI2 225 and subtract that number from the total TBS. The number of REs occupied by the SCI2 225 (or the number of modulation symbols, which can indicate the number of REs) can be defined by the following equation 1.

[0079]

[0080] Q' SCI2 may be the number of modulation symbols occupied by SCI2 225 (e.g., where the number of modulation symbols may be equal to the number of REs occupied by SCI2 255), O SCI2 is the number of bits of SCI format 0 - 2 (e.g., SCI2), and L SCI2 is the number of CRC bits for SCI2 (e.g., can be any number of bits). In some cases, may be the value indicated in the corresponding SCI format 0–1 (e.g., SCI1) message, and may be for OFDM symbol l (for l = 0, 1, 2, …, ) in the transmission of SCI2 in data channel transmission (e.g., in the transmission of SCI2 225 on PSSCH 235) the number of REs. may be the number of symbols allocated for PSSCH 235. In some cases, may exclude one or more automatic gain control (AGC) symbols defined by the specification, for example. In some cases, α may be a value configured by a higher layer parameter (such as, SL scaling). In some cases, K r may be the size of the r - th code block for PSSCH transmission. In some cases, may be similar to or equal to TBS. For example, if there is one code block or the TB is divided into multiple code blocks, then may be equal to or slightly larger than TBS. In some cases, when there is one code block, UE 115 may use more shortened bits, which may result in a relatively large difference between and TBS.

[0081] In some examples, the number of REs occupied by SCI2 225 (e.g., corresponding to the modulation symbols for SCI2 2225) may depend on TBS. For example, K r may depend on TBS. Thus, UE 115 may attempt to determine TBS in order to calculate the number of REs occupied by SCI2225. To calculate TBS for PSSCH 235, UE 115 may calculate the number of available REs per PRB based on Equation 2 below.

[0082]

[0083] N' RE may be the number of available REs per PRB, may be the number of symbols in an RB (e.g., 12 symbols), may be the number of symbols allocated for PSSCH 235, can be the number of REs per PRB in the channel for the scheduled demodulation reference signal (DMRS) (e.g., the overhead associated with the DMRS), and can be a configured overhead (e.g., can be semi-statically configured to 0, 6, 12, or 18).

[0084] UE 115 can use the calculated number of available REs per PRB to determine the number of available REs for transmitting SCI2 225 and data 230 on PSSCH 235 (e.g., the number of available REs per channel), and UE 115 can use this number to determine the TBS. In some cases, the number of available REs per channel can be determined per time slot or per TTI. For example, UE115 can calculate the number of available REs for PSSCH 235 based on Equation 3 below.

[0085] N RE = min(n, N′ RE )·n PRB (3)

[0086] In some cases, N RE can be the number of available REs in PSSCH 235, n can be a constant corresponding to the upper limit or maximum number of available REs per TTI for a PRB (e.g., 144 or 156), and n PRB can be the total number of allocated PRBs for UE 115 (e.g., resource allocation). In some examples, UE 115 can use the number of available REs in PSSCH 235 to determine the TBS. However, as shown in Equation 2 and Equation 3, such calculations for the TBS do not account for the overhead of SCI2 225, which can potentially lead to the misaligned code rates described herein. Further, UE 115 may not be able to simply add the overhead of SCI2225 to the above equation because the overhead is the variable that UE 115 is initially trying to solve for to use the TBS. Thus, a circular dependency situation occurs, and UE 115 may not be able to determine the number of REs occupied by SCI2 225. For example, the overhead of SCI2 2225 can be calculated based on the TBS, which can be calculated based on the number of available REs in PSSCH 235 (e.g., the number of REs that can include data 230), and the number of available REs in PSSCH 235 can be calculated based on the overhead of SCI2 225. Thus, the receiving UE115-b may not be able to determine which part or how many REs in PSSCH 235 are used to determine the TBS associated with a code rate similar (or identical) to the code rate used by the transmitting UE 115-a.

[0087] In some implementations of the present disclosure, UE 115-a and UE 115-b may be configured with one or more mutually understood rules that may enable UE 115-a and UE 115-b to exclude from the available REs in PSSCH 235 the number of REs occupied by SCI2 225 when performing the TBS determination procedure. In some examples, UE 115-a and UE 115-b may determine the TBS excluding the number of REs occupied by SCI2 225 based on a shared approximation (e.g., estimate or assumption) of the overhead of SCI2 225.

[0088] In some examples, UE 115-a and UE 115-b may use the same RE overhead approximation to determine an approximate TBS (e.g., an intermediate TBS), and UE 115-a and UE 115-b may use the approximate TBS to determine the actual or exact overhead of SCI2 225. UE 115-a and UE 115-b may use the actual or exact overhead of SCI2 225 to determine the actual TBS (e.g., by excluding from the available REs in PSSCH 235 the number of REs occupied by SCI2 255 in the TBS calculation). Thus, UE 115-a and UE 115-b may determine the same actual TBS for PSSCH 235 and, correspondingly, may use a similar or the same code rate, which may increase the likelihood of successful decoding at UE 115-b and may result in more reliable wireless communication. In some other examples, UE115-a and UE 115-b may use the approximate TBS to determine a similar or the same code rate for one or both of SCI2 225 or data 230. Refer to Figure 3 Additional details of the mutually understood rules are described.

[0089] Figure 3 Illustrates an example of process flow 300 that supports TBS determination for two-stage control in accordance with various aspects of the present disclosure. In some examples, process flow 300 may be implemented or be made to implement aspects of wireless communication system 100 or wireless communication system 200. In accordance with the techniques described herein, process flow 300 may include several operations performed by a device (such as, for example, UE 115 as described with reference to Figure 1 and 2 . In some examples, the operations illustrated in process flow 300 may be performed by hardware (e.g., including circuitry, processing blocks, logic components, and other components), by code executed by a processor (e.g., software or firmware), or any combination thereof.

[0090] In some examples, the device may monitor a data channel to receive a control message (e.g., a second-stage control message, such as SCI2 225 as described with reference to Figure 2 and a data message (such as, for example,Figure 2 the described data 230). The device can implement process flow 300 to accurately and consistently determine the code rate associated with the data channel based on the TBS associated with the REs available for data transmission on the data channel (e.g., excluding the REs occupied by control messages). In some examples, the device can implement process flow 300 to break circular dependencies, such as the circular dependencies described with reference to Figure 2 the described circular dependencies.

[0091] At 305, the device can determine a first RE overhead. In some examples, the first RE overhead can be an approximation or estimate of the number of REs that control messages can occupy in the data channel. In some implementations, the estimated RE overhead is determined for the purpose of determining a first TBS (e.g., an intermediate TBS or a hypothesized TBS).

[0092] In some examples, the estimated RE overhead can be a pre-determined value (e.g., a specified value pre-configured at both the transmitting device and the receiving device). For example, the device can store the pre-determined value and can use the stored pre-determined value as the estimated RE overhead. In some cases, the estimated RE overhead can be calculated based on one or more pre-configured values. For example, one or more variables in Equation 1 (e.g., α, etc.) can be pre-configured, and the device can use Equation 1 or the pre-configured values to determine the estimated RE overhead.

[0093] Additionally or alternatively, in some specific examples, the denominator term in Equation 1 (e.g., a term calculated based on the TBS, which can be unknown) can be expressed as an approximate or estimated ratio to one or more other terms in Equation 1 (e.g., one or more variables in the numerator). For example, the device can determine to use a ratio to approximately express the term and one or more other terms based on a known target MCS (e.g., the known target MCS of the data channel indicated in a first-stage control message). In this way, the device can break the circular dependency and can solve Equation 1 (e.g., solve an approximation of Equation 1) for an approximate or estimated number of REs occupied by control messages (e.g., second-stage control messages).

[0094] In some other examples, a parameter may explicitly indicate the estimated RE overhead. For example, a device may identify an RRC parameter that indicates a first RE overhead (e.g., the RRC parameter may indicate that the first RE overhead is 10 REs). Additionally or alternatively, the estimated RE overhead may be signaled in a first-stage control message (e.g., SCI1). In some examples, a device may receive a first-stage control message in a control channel and may identify a field that indicates a value (e.g., a number of REs) that the device may use for the estimated RE overhead. In some other examples, a device may receive a first-stage control message and may identify an index included in the first-stage control information that corresponds to the estimated RE overhead that the device is to use. For example, a device may store a pre-determined or pre-configured number of estimated RE overhead values (e.g., in a look-up table in a memory), and the first-stage control message may indicate via the index or one or more bits which estimated RE overhead value the device may use. In some cases, a device may store a pre-configured estimated RE overhead value, and a transmitting device may indicate the estimated RE overhead (e.g., in SCI1) to overwrite the pre-configured value.

[0095] In some examples, a device may use an estimated RE overhead value that is independent of a second-stage control message. For example, a device may use a number that may include a plurality of different RE overheads associated with a data channel. For example, a device may identify a first RE overhead associated with the term -( + ) in Equation 2, which may include an overhead associated with DMRS and an overhead indicated semi-statically. In such examples, the first RE overhead may be pre-determined (e.g., defined in a specification), pre-configured, or indicated to the device in a first-stage control message or other signaling (e.g., RRC signaling).

[0096] At 310, the device may determine a TBS (e.g., a first TBS or an intermediate TBS) based on the estimated RE overhead. In some examples, the first TBS may be an approximation or estimate of an actual TBS associated with a data channel. In some aspects, the first TBS may be an intermediate TBS that is similarly determined by the device and any other device that communicates with the device using the data channel. As such, the first TBS may be a consistent value for which subsequent TBS and code rate calculations may be computed for the device and any other device based on this value. As such, communicating devices may compute similar code rates.

[0097] The device may determine the first TBS based on whether the estimated RE overhead is determined per PRB or per PSSCH (e.g., per channel). If the estimated RE overhead is defined per PRB, the estimated RE overhead may be included in Equation 2. For example, when the estimated RE overhead is determined per PRB, the first TBS may be computed based on Equation 4.

[0098]

[0099] N RE = min(n, N′ RE )·n PRB (4)

[0100] In some cases, it may be the estimated RE overhead per PRB. In some examples, for additional or alternative examples of how to determine the estimated RE overhead at 305, it may be signaled in the first-stage control message or the second-stage control message. In some specific examples, the first-stage control message or the second-stage control message may signal that it is one of a set of configurable values (e.g., 0, 6, 12, or 18). In such examples, it may be dynamically selected by the transmitting device and signaled to the receiving device. In some examples, it may be a separate field in addition to (e.g., separate from ). For example, in the case where is a separate value in addition to , the first TBS may be determined based on Equation 5.

[0101]

[0102] N PE = min(n, N· RE )·n PRB (5)

[0103] In Equation 5, can be configured semi-statically, while can be determined dynamically (e.g., based on SCI1) or pre-configured.

[0104] If the estimated RE overhead is defined per PSSCH, the estimated RE overhead may be included (e.g., attached to) in Equation 3. For example, when the estimated RE overhead is determined per PSSCH, the first TBS can be calculated according to Equation 6. In some cases, N RE，oh may be the estimated RE overhead per PSSCH.

[0105]

[0106] At 315, the device may determine the number of modulation symbols for a control message (e.g., the actual number of modulation symbols for SCI2) based on a first TBS (e.g., an intermediate TBS for a hypothesized PSSCH transmission). In some aspects, the control message may be a rank-1 transmission, and correspondingly, the number of modulation symbols for the control message may be equal to the number of REs used to transmit the control message. In some additional aspects, the data channel may be two-layer, and the modulation symbols for the control message may be repeated across the two layers.

[0107] In some implementations, the device may use the first TBS to determine the number of bits in each code block, which may be associated with the value of the term in Equation 1 for For example, may be calculated based on the first TBS (e.g., the intermediate TBS), and correspondingly, may be different from the actual TBS. In some specific instances, may be the intermediate TBS. For example, in the context of the TBS and code rate determination procedure in sidelink communication, K r may correspond to the size of the r-th code block for a hypothesized sidelink shared channel transmission for the intermediate TBS. In some implementations, the device may use Equation 1 and the value associated with the intermediate TBS (e.g., as opposed to using the actual TBS for the data channel in Equation 1) to determine the number of modulation symbols for the control message.

[0108] At 320, the device may encode or decode one or both of the control message and the data message based on the determined number of modulation symbols for the control message. In an example where the device is a transmitting device and transmits the control message on the data channel, the device may encode one or both of the control message and the data message based on the determined number of modulation symbols for the control message. Alternatively, in an example where the device is a receiving device and receives the control message from another device on the data channel, the device may decode one or both of the control message and the data message based on the determined number of modulation symbols for the control message.

[0109] At 325, the device may determine a second TBS. In some examples, the second TBS may be the actual TBS for a data channel (e.g., PSSCH) and may be the same as or different from the first TBS (e.g., the intermediate TBS). Based on the device (e.g., the device transmitting or receiving on the data channel) having more accurate information about the available resources for PSSCH transmission than when the first TBS was determined (e.g., especially regarding the RE overhead of control messages on the PSSCH), the second TBS determination procedure may be more accurate than the first TBS determination procedure for the data channel. For example, the device may determine the exact RE overhead of a control message (e.g., SCI2) on the data channel (e.g., PSSCH).

[0110] The device may determine the second TBS based on subtracting the determined number of REs for the control message from the number of REs (e.g., the number of available REs) used for TBS calculation. In some examples, the determined number of REs may correspond to the number of modulation symbols calculated for the control message at 315. In such examples, the device may subtract the calculated number of REs (e.g., the actual number of REs for the control message, rather than the estimated number of REs for the control message) from the number of available REs.

[0111] Additionally or alternatively, the number of REs associated with the control message may be signaled in the control message. For example, the control message may include a field or value indicating the number of REs to be subtracted from the number of available REs for the second TBS calculation. The transmitting device may dynamically select the indicated number of REs (e.g., based on the actual number of REs for the control message, the retransmission procedure for the control message, data, or both, or some combination thereof). In some implementations, the control message may indicate whether physical sidelink feedback channel (PSFCH) symbols may be excluded (e.g., subtracted) from the number of available REs. Additionally or alternatively, the control message may indicate whether channel state information (CSI) reference signal (CSI-RS) overhead may be excluded from the number of available REs. In such examples, the device may subtract the indicated number (or numbers) of REs from the number of available REs and may use the updated number of available REs (e.g., after subtracting the REs) to determine the actual TBS for the data channel.

[0112] In some examples, the device may calculate the number of REs for the control message and receive one or more indications of one or more numbers of REs to be excluded from the number of available REs indicated in the control message. In such examples, the device may exclude the sum of the calculated actual number of REs for the control message and the one or more numbers of REs indicated by the control message. In some implementations, the control message may indicate one or more numbers of REs to be excluded from the number of available REs to optimize or adjust the number of REs calculated by the device for the control message.

[0113] In some aspects, the control message may additionally indicate a relatively small number of REs to be excluded from the number of available REs based on the actual number of REs calculated for the control message. Thus, in cases where the device is completely dependent on one or more indications in the control message, the control message can use a smaller number of bits. Further, the number of REs indicated by the control message for exclusion from the number of available REs can be defined per PRB and can thus be associated with a multiplication operation, similar to that described in Equation 3: N RE = min(n, N′ RE )·n PRB . The multiplication operation can increase the impact of each bit among the number of bits carried by the control message. Thus, the control message can carry a small number of bits (e.g., indicating a small number of REs), but the multiplication operation can convert the small number to a larger number (e.g., large n PRB times).

[0114] At 330, the device may encode or decode a data channel (including one or both of a control message and a data message) based on the second TBS. For example, in a case where the device is a transmitting device, the device may encode the data channel (e.g., PSSCH data transmission on the PSSCH) based on the second TBS. In a case where the device is a receiving device, the device may decode the data channel based on the second TBS. In some examples, the device may determine a code rate based on the determined second TBS, which may include the number of REs excluding the number of REs associated with the overhead (e.g., control message) of the data channel. In some implementations, this can enable the device to determine a code rate similar to or the same as the code rate used by the transmitting device during the encoding process for the data channel. Thus, compared to different devices that determine the code rate based on TBS calculations where the number of available REs does not account for the control message overhead (or inaccurately accounts for the control message overhead), the receiving device may have a higher likelihood of successfully decoding the data channel. Thus, the device may decode the data channel based on the second TBS according to rules mutually understood between the receiving device and the transmitting device.

[0115] Figure 4An example of a process flow 400 that supports TBS determination for two-stage control in accordance with various aspects of the present disclosure is illustrated. In some examples, the process flow 400 may be implemented or implemented to achieve aspects of the wireless communication system 100 or the wireless communication system 200. In the following description of the process flow 400, the communication between the UE 115-c and the base station 115-d may be transmitted in an order different from the order shown, or the operations performed by the UE 115-c and the UE 115-d may be performed in a different order or at different times. Certain operations may also be excluded from the process flow 400, or other operations may be added to the process flow 400. In some examples, the UE 115-c and the UE 115-d may support mutually understood rules that may enable the UE 115-c and the UE 115-d to independently determine similar (or the same) code rates for encoding or decoding data channels (including one or both of control messages or data messages) according to the techniques described herein.

[0116] At 405, the UE 115-c may transmit a first-stage control message (e.g., SCI1) to the UE 115-d. In some examples, the first-stage control information may include one or more of a second-stage control information format, resource allocation (e.g., for a scheduled data channel), or MCS, and other control information fields. In some cases, the UE 115-c may transmit the first-stage control message on a sidelink control channel (such as, the PSCCH).

[0117] At 410, the UE 115-c may generate a control message. As described herein, the control message may be an example of a second-stage control message (e.g., SCI2).

[0118] At 415, the UE 115-c may determine the estimated RE overhead. In some examples, the UE 115-c may determine the estimated RE overhead for the purpose of determining an intermediate TBS associated with a scheduled data channel, as described in more detail with reference to Figure 3 The estimated RE overhead may be associated with the control message generated at 410. For example, the estimated RE overhead may approximately account for the RE overhead of the control message. In some cases, the first-stage control message transmitted at 405 may include an indication of the estimated RE overhead.

[0119] At 420, the UE 115-c may determine the TBS. In some examples, the TBS may be an intermediate TBS (e.g., the first TBS), and the UE 115-c may use the TBS to determine the actual RE overhead and the actual TBS, as described in more detail with reference to Figure 3 More detailed description.

[0120] At 425, UE 115-c may encode a control message (e.g., a second-phase control message) according to the TBS. In some examples, UE 115-c may encode the control message based on the number of modulation symbols for the control message, where the number of modulation symbols may be determined based on the TBS. Additionally or alternatively, UE 115-c may encode a data message according to the TBS associated with the control message generated at 410 or the estimated RE overhead.

[0121] At 430, UE 115-c may determine a second RE overhead. In some examples, the second RE overhead may be the actual RE overhead for the control message, a value indicated in the control message, or a combination thereof, as described in more detail with reference to Figure 3 More detailed description.

[0122] At 435, UE 115-c may determine a second TBS. In some examples, the second TBS may be the actual TBS and may include the number of REs excluding the number of REs associated with the overhead of the data channel (e.g., the second RE overhead) of the data channel, as described in more detail with reference to Figure 3 More detailed description.

[0123] At 440, UE 115 may encode a data message according to the second TBS. In some examples, UE 115-c may encode the data message according to the second TBS based on rules mutually understood between UE 115-c and UE 115-d, as described in more detail with reference to Figure 3 More detailed description. In some aspects, in examples where UE 115-c suppresses encoding the data message according to the first TBS (or the estimated RE overhead) at 425, UE 115-c may encode the data message according to the second TBS.

[0124] At 445, UE 115-c may transmit the encoded control message, and at 450, UE 115-c may transmit the encoded data message. In some examples, UE 115-c may transmit the encoded control message and the encoded data message in the same data channel (e.g., a sidelink shared channel). In some cases, the encoded control message may rate-match around the encoded data message.

[0125] At 455, UE 115-d may determine the estimated RE overhead. In some aspects, UE 115-d may determine the same estimated RE overhead as UE 115-c based on a preconfigured value of the estimated RE overhead or based on receiving an indication of the estimated RE overhead in the first-phase control message at 405. In some examples, UE 115-d may determine the estimated RE overhead for the purpose of determining an intermediate TBS associated with the data channel, as described in more detail with reference to Figure 3 More detailed description.

[0126] At 460, UE 115-d may determine the TBS. In some aspects, UE 115-d may determine a TBS similar to or the same as that of UE 115-c. In some examples, the TBS may be an intermediate TBS (e.g., the first TBS), and UE 115-d may use this TBS to determine the actual RE overhead and the actual TBS, as described in Figure 3 more detail.

[0127] At 465, UE 115-d may decode a control message (e.g., a second-phase control message) based on the TBS. Additionally, in some examples, UE 115-d may decode the control message based on the number of modulation symbols calculated for the control message, as described in Figure 3 more detail. Additionally or alternatively, UE 115-d may decode the encoded data message based on the TBS associated with the control message or the estimated RE overhead.

[0128] At 470, UE 115-d may determine a second RE overhead. In some aspects, UE 115-d may determine a second RE overhead similar to or the same as that of UE 115-c. In some examples, the second RE overhead may be the actual RE overhead for the control message, a value indicated by the control message, or a combination thereof, as described in Figure 3 more detail.

[0129] At 475, UE 115-d may determine a second TBS. In some aspects, UE 115-d may determine a second TBS similar to or the same as that of UE 115-c. In some examples, the second TBS may be the actual TBS for the data channel and may include the number of REs excluding the number of REs associated with the overhead of the data channel (e.g., including the second RE overhead), as described in Figure 3 more detail.

[0130] At 480, UE 115-d may decode the data message based on the second TBS. In some examples, UE 115-d may decode the data message based on the second TBS according to rules mutually understood between UE 115-c and UE 115-d, as described in Figure 3 more detail. In some aspects, in examples where UE 115-d suppresses decoding the data message based on the first TBS (or the estimated RE overhead) at 465, UE 115-d may decode the data message based on the second TBS.

[0131] Figure 5FIG. 500 is a block diagram of a device 505 supporting TBS determination for two-stage control in accordance with aspects of the present disclosure. The device 505 may be an example of aspects of a UE 115 as 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 one another (e.g., via one or more buses).

[0132] 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 two-stage control, 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.

[0133] In some implementations, the communication manager 515 may generate a control message, determine an estimated RE overhead associated with the control message, encode the control message according to a TBS based on the estimated RE overhead, and transmit the encoded control message. Additionally or alternatively, the communication manager 515 may receive an encoded control message, determine an estimated RE overhead associated with the encoded control message, and decode the encoded control message according to a TBS based on the estimated RE overhead. The communication manager 515 may be an example of aspects of the communication manager 810 described herein.

[0134] In some other implementations, the communication manager 515 may encode a data message according to a TBS based on an estimated RE overhead associated with a control message, where the estimated RE overhead is different from the actual RE overhead for the control message, and transmit the encoded data message to a second UE. Additionally or alternatively, the communication manager 515 may receive an encoded data message from a first UE, and decode the encoded data message according to a TBS based on an estimated RE overhead associated with the control message, where the estimated RE overhead is different from the actual RE overhead for the control message.

[0135] The 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 the communication manager 515 or its sub-components may be performed by a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (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 the present disclosure.

[0136] The communication manager 515 or its sub-components may be physically located at various positions, including being distributed such that portions of the functionality are implemented by one or more physical components at different physical locations. In some examples, in accordance with various aspects of the present disclosure, the communication manager 515 or its sub-components may be separate and distinct components. In some examples, in accordance with various aspects of the present disclosure, the 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 the present disclosure, or combinations thereof.

[0137] The transmitter 520 may transmit signals generated by other components of the device 505. In some examples, the transmitter 520 may be co-located with the receiver 510 in a transceiver module. For example, the transmitter 520 may be an example of aspects of the transceiver 820 described with reference to Figure 8 The transmitter 520 may utilize a single antenna or an antenna array.

[0138] As described herein, the communication manager 515 may be implemented to achieve one or more potential advantages. One implementation may allow a device 505 that conveys control information in the same data channel as data that may be decoded based on the control information to consistently and accurately determine a code rate that matches the code rate used by another device based on a common TBS determination procedure for the data channel. In some examples, the common TBS determination procedure may enable two communication devices to have a greater likelihood of successful communication, thereby reducing the number of retransmissions on the data channel. Reducing the number of retransmissions may reduce the signaling overhead and communication latency on the data channel (e.g., PSSCH).

[0139] Furthermore, by implementing a common TBS determination procedure, the device 505 may reduce the number of processing operations associated with encoding and transmitting a data message or receiving and decoding a data message. For example, if the device 505 is a transmitting device (e.g., the device 505 transmits a data message), the device 505 may reduce the number of retransmissions of the data message because the device 505 may use a code rate similar (or identical) to the code rate used by the receiving device to decode the data message to encode the data message, thereby increasing the likelihood of successful reception. Reducing the number of data message retransmissions may reduce the processor ramp-up processing power and the number of times the processing unit is opened to perform retransmissions. Similarly, if the device 505 is a receiving device (e.g., the device 505 receives a data message), the device 505 is more likely to successfully receive the data message and may avoid performing several processing operations associated with monitoring and attempting to decode multiple retransmissions of the data channel.

[0140] Based on techniques for more efficient and consistent TBS and code rate determination, device 505 may experience improved power savings and increased battery life. For example, based on reducing the number of processing operations, device 505 may power down or turn off several processing units associated with encoding and transmitting or receiving and decoding messages.

[0141] Figure 6 Block diagram 600 of a device 605 supporting TBS determination for two-stage control in accordance with aspects of the present disclosure is shown. Device 605 may be an example of aspects of device 505 or UE 115 as described herein. Device 605 may include a receiver 610, a communication manager 615, and a transmitter 640. Device 605 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

[0142] 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 two-stage control, etc.). The information may be passed to other components of device 605. Receiver 610 may be an example of aspects of transceiver 820 described with reference to Figure 8 Receiver 610 may utilize a single antenna or an antenna array.

[0143] Communication manager 615 may be an example of aspects of communication manager 515 as described herein. Communication manager 615 may include a two-stage control manager 620, an overhead manager 625, an encoding manager 630, and a decoding manager 635. Communication manager 615 may be an example of aspects of communication manager 810 described herein.

[0144] In some implementations, two-stage control manager 620 may generate a control message. Overhead manager 625 may determine the estimated RE overhead associated with the control message (e.g., where the estimated RE overhead may be different from the actual RE overhead for the control message). Encoding manager 630 may encode the control message according to a TBS based on the estimated RE overhead. Two-stage control manager 620 may transmit the encoded control message. Additionally or alternatively, two-stage control manager 620 may receive the encoded control message. Overhead manager 625 may determine the estimated RE overhead associated with the encoded control message (e.g., where the estimated RE overhead may be different from the actual RE overhead for the encoded control message). Decoding manager 635 may decode the encoded control message according to a TBS based on the estimated RE overhead.

[0145] In some other implementations, the encoding manager 630 may encode data messages according to a TBS based on an estimated RE overhead associated with a control message, where the estimated RE overhead is different from the actual RE overhead for the control message. The two-stage control manager 620 may transmit the encoded data message to a second UE. Additionally or alternatively, the two-stage control manager 620 may receive the encoded data message from a first UE. The decoding manager 635 may decode the encoded data message according to a TBS based on an estimated RE overhead associated with the control message, where the estimated RE overhead is different from the actual RE overhead for the control message.

[0146] The transmitter 640 may transmit signals generated by other components of the 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.

[0147] Figure 7 FIG. 705 is a block diagram of a communication manager 700 supporting TBS determination for two-stage control 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 a two-stage control manager 710, an overhead manager 715, an encoding manager 720, a TBS manager 725, an RE manager 730, and a decoding manager 735. Each of these modules may communicate directly or indirectly with each other (e.g., via one or more buses). The communication manager 705 may perform methods for wireless communication as described herein, where the methods for wireless communication may be implemented by a UE 115.

[0148] In some implementations, the two-stage control manager 710 may generate a control message. The overhead manager 715 may determine an estimated RE overhead associated with the control message. In some examples, the estimated RE overhead associated with the control message is different from the actual RE overhead for the control message. The encoding manager 720 may encode data information or a control message according to a TBS based on the estimated RE overhead. In some examples, the encoding manager 720 may determine the number of modulation symbols for the control message based on the TBS, where the data message or the control message is encoded according to the number of modulation symbols. The two-stage control manager 710 may transmit the encoded data message or the encoded control message.

[0149] In some examples, the TBS is an example of a first TBS (e.g., an intermediate TBS), and the overhead manager 715 may determine a second RE overhead based on one or both of the actual RE overhead for a control message or the overhead value indicated in the control message. The TBS manager 725 may determine a second TBS based on the second RE overhead. In some examples, the encoding manager 720 may encode a data message according to the second TBS, and the two-stage control manager 710 may transmit the encoded data message. In some cases, the encoded control message and the encoded data message are transmitted in a sidelink shared channel. In some cases, the encoded control message schedules the transmission of the encoded data message.

[0150] In some examples, the RE manager 730 may determine the number of available REs for the sidelink shared channel, and the TBS manager 725 may subtract the second RE overhead from the number of available REs to obtain an updated number of available REs for the sidelink shared channel, wherein the second TBS is determined based on the updated number of available REs.

[0151] In some cases, the estimated RE overhead is an example of a preconfigured value. In some other cases, the control message may be an example of a second-stage control message, and the two-stage control manager 710 may transmit a first-stage control message (wherein the first-stage control information indicates the estimated RE overhead) to a second UE in a sidelink control channel and may transmit a second-stage control message to the second UE in a sidelink shared channel. In some examples, the estimated RE overhead is defined per PRB or per channel.

[0152] In some additional or alternative implementations, the two-stage control manager 710 may receive an encoded data message or an encoded control message from a first UE. The overhead manager 715 may determine the estimated RE overhead associated with the encoded control message. In some examples, the estimated RE overhead associated with the encoded control message is different from the actual RE overhead for the encoded control message. The decoding manager 735 may decode the encoded data information or the encoded control message according to a TBS based on the estimated RE overhead. In some examples, the decoding manager 735 may determine the number of modulation symbols for the encoded control message based on the TBS, wherein the encoded data message or the encoded control message is decoded according to the number of modulation symbols.

[0153] In some examples, the TBS is an example of a first TBS (e.g., an intermediate TBS), and the overhead manager 715 may determine a second RE overhead based on one or both of the actual RE overhead for the encoded control message or the overhead value indicated in the encoded control message. The TBS manager 725 may determine a second TBS based on the second RE overhead. In some examples, the two-stage control manager 710 may receive an encoded data message, and the decoding manager 735 may decode the encoded data message according to the second TBS. In some cases, the encoded control message and the encoded data message are received in a sidelink shared channel. In some cases, the encoded data message is decoded based on information decoded from the encoded control message.

[0154] In some examples, the RE manager 730 may determine the number of available REs for the sidelink shared channel, and the TBS manager 725 may subtract the second RE overhead from the number of available REs to obtain an updated number of available REs for the sidelink shared channel, where the second TBS is determined based on the updated number of available REs.

[0155] In some cases, the estimated RE overhead is an example of a preconfigured value. In some other cases, the encoded control message may be an example of a second-stage control message, and the two-stage control manager 710 may receive a first-stage control message (where the first-stage control information indicates the estimated RE overhead) from a first UE in a control channel and may receive a second-stage control message from the first UE in a sidelink shared channel. In some examples, the estimated RE overhead is defined per PRB or per channel.

[0156] Figure 8 FIG. shows a diagram of a system 800 including a device 805 that supports TBS determination for two-stage control in accordance with 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 communications, 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).

[0157] In some implementations, the communication manager 810 may generate a control message, determine the estimated RE overhead associated with the control message, encode the control message according to a TBS based on the estimated RE overhead, and transmit the encoded control message. Additionally or alternatively, the communication manager 810 may receive an encoded control message, determine the estimated RE overhead associated with the encoded control message, and decode the encoded control message according to a TBS based on the estimated RE overhead.

[0158] In some other implementations, the communication manager 810 may encode a data message according to a TBS based on the estimated RE overhead associated with a control message, where the estimated RE overhead is different from the actual RE overhead for the control message, and transmit the encoded data message to a second UE. Additionally or alternatively, the communication manager 810 may receive an encoded data message from a first UE and decode the encoded data message according to a TBS based on the estimated RE overhead associated with the control message, where the estimated RE overhead is different from the actual RE overhead for the control message.

[0159] The I / O controller 815 may manage the 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, keyboard, mouse, touch screen, or similar device. 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 a hardware component controlled by the I / O controller 815.

[0160] The transceiver 820 may perform two-way communication via one or more antennas, wired or wireless links, as described herein. For example, the transceiver 820 may represent a wireless transceiver and may perform two-way communication with another wireless transceiver. The transceiver 820 may 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.

[0161] In some cases, the wireless device may include a single antenna 825. However, in some cases, the device may have more than one antenna 825, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

[0162] The memory 830 may include a random access memory (RAM) and a read-only memory (ROM). The memory 830 may store computer-readable, computer-executable code 835 including instructions that, when executed, cause the processor to perform the various functions described herein. In some cases, the memory 830 may in particular include a basic input / output system (BIOS) that may control basic hardware or software operations, such as interactions with peripheral components or devices.

[0163] The processor 840 may include intelligent hardware devices (e.g., a general-purpose processor, a DSP, a central processing unit (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 may be configured to operate a memory array using a memory controller. In other cases, the memory controller may be integrated into the processor 840. The processor 840 may 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., support the functions or tasks for TBS determination for two-stage control).

[0164] The code 835 may include instructions for implementing aspects of the present disclosure, including instructions for supporting wireless communication. The code 835 may 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 may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

[0165] Figure 9 A flowchart of a method 900 for supporting TBS determination for two-stage control in accordance with aspects of the present disclosure is shown. The operations of method 900 may be implemented by a UE 115 or its components as described herein. For example, the operations of method 900 may be performed by a communication manager as described with reference to Figures 5 to 8 In some examples, the UE may execute an instruction set to control functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the functions described herein.

[0166] At 905, the UE may encode a data message according to a TBS based on an estimated RE overhead associated with a control message, where the estimated RE overhead is different from the actual RE overhead for the control message. 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 encoding manager as described with reference to Figures 5 to 8 as described.

[0167] At 910, the UE may transmit an encoded data message to a second UE. 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 two-stage control manager as described with reference to Figures 5 to 8 as described.

[0168] Figure 10 FIG. 1000 is a flow diagram of a method 1000 that supports TBS determination for two-stage control in accordance with aspects of the present disclosure. The operations of method 1000 may be implemented by a UE 115 or components thereof 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 as described. In some examples, the UE may execute an instruction set to control functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the functions described herein.

[0169] At 1005, the UE may encode a data message according to a TBS based on an estimated RE overhead associated with a control message, where the estimated RE overhead is different from the actual RE overhead for the control message. 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 encoding manager as described with reference to Figures 5 to 8 as described.

[0170] At 1010, the UE may determine a second RE overhead based on one or both of the actual RE overhead for the control message or an overhead value indicated in the control message. 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 an overhead manager as described with reference to Figures 5 to 8 as described.

[0171] At 1015, the UE may determine a second TBS based on the second RE overhead. The operation of 1015 may be performed according to the methods described herein. In some examples, aspects of the operation of 1015 may be performed by a TBS manager as described with reference to Figures 5 to 8 as described.

[0172] At 1020, the UE may transmit the encoded data message to the second UE. The operation of 1020 may be performed according to the methods described herein. In some examples, aspects of the operation of 1020 may be performed by a two-stage control manager as described with reference to Figures 5 to 8 as described.

[0173] Figure 11FIG. 1100 is a flow diagram of a method for supporting TBS determination for two-stage control in accordance with aspects of the present disclosure. Operations of method 1100 may be implemented by a UE 115 or components thereof as described herein. For example, 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 a set of instructions to control functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use special purpose hardware to perform aspects of the functions described herein.

[0174] At 1105, the UE may encode a data message according to a TBS based on an estimated RE overhead associated with a second-stage control message, where the estimated RE overhead is different from an actual RE overhead for the second-stage control message. The operation of 1105 may be performed according to methods described herein. In some examples, aspects of the operation of 1105 may be performed by an encoding manager as described with reference to Figures 5 to 8 as described.

[0175] At 1110, the UE may transmit a first-stage control message in a sidelink control channel to a second UE, where the first-stage control information indicates the estimated resource element overhead. The operation of 1110 may be performed according to methods described herein. In some examples, aspects of the operation of 1110 may be performed by a two-stage control manager as described with reference to Figures 5 to 8 as described (e.g., using a transmitter or transceiver).

[0176] At 1115, the UE may transmit a second-stage control message in a sidelink shared channel to the second UE. The operation of 1115 may be performed according to methods described herein. In some examples, aspects of the operation of 1115 may be performed by a two-stage control manager as described with reference to Figures 5 to 8 as described (e.g., using a transmitter or transceiver).

[0177] At 1120, the UE may transmit the encoded data message to the second UE. The operation of 1120 may be performed according to methods described herein. In some examples, aspects of the operation of 1120 may be performed by a two-stage control manager as described with reference to Figures 5 to 8 as described (e.g., using a transmitter or transceiver).

[0178] Figure 12 FIG. 1200 is a flow diagram of a method for supporting TBS determination for two-stage control in accordance with aspects of the present disclosure. Operations of method 1200 may be implemented by a UE 115 or components thereof as described herein. For example, operations of method 1200 may be performed by a communication manager as described with reference to Figures 5 to 8Performed by the described communication manager. In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the functions described herein.

[0179] At 1205, the UE may receive an encoded data message from a first UE. The operation of 1205 may be performed according to the methods described herein. In some examples, aspects of the operation of 1205 may be performed by a two-stage control manager as described with reference to Figures 5 to 8 The described two-stage control manager.

[0180] At 1210, the UE may decode the encoded data message according to a TBS based on the estimated RE overhead, where the estimated RE overhead is different from the actual resource element overhead for the control message. The operation of 1210 may be performed according to the methods described herein. In some examples, aspects of the operation of 1210 may be performed by a decoding manager as described with reference to Figures 5 to 8 The described decoding manager.

[0181] Figure 13 A flowchart of a method 1300 supporting TBS determination for two-stage control in accordance with aspects of the present disclosure is shown. The operations of method 1300 may be implemented by a UE 115 or its components as described herein. For example, the operations of method 1300 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 the functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the functions described herein.

[0182] At 1305, the UE may receive an encoded data message from a first UE. The operation of 1305 may be performed according to the methods described herein. In some examples, aspects of the operation of 1305 may be performed by a two-stage control manager as described with reference to Figures 5 to 8 The described two-stage control manager.

[0183] At 1310, the UE may decode the encoded data message according to a TBS based on the estimated RE overhead, where the estimated RE overhead is different from the actual resource element overhead for the control message. The operation of 1310 may be performed according to the methods described herein. In some examples, aspects of the operation of 1310 may be performed by a decoding manager as described with reference to Figures 5 to 8 The described decoding manager.

[0184] At 1315, the UE may determine a second RE overhead based on one or both of the actual RE overhead for the control message or the overhead value indicated in the control message. The operation of 1315 may be performed according to the methods described herein. In some examples, aspects of the operation of 1315 may be performed by an overhead manager as described with reference to Figures 5 to 8 described.

[0185] At 1320, the UE may determine a second TBS based on the second RE overhead. The operation of 1320 may be performed according to the methods described herein. In some examples, aspects of the operation of 1320 may be performed by a TBS manager as described with reference to Figures 5 to 8 described.

[0186] Figure 14 A flowchart of a method 1400 for supporting TBS determination for two-stage control in accordance with aspects of the present disclosure is shown. The operations of method 1400 may be implemented by a UE 115 or components thereof as described herein. For example, the operations of method 1400 may be performed by a communication manager as described with reference to Figures 5 to 8 described. In some examples, the UE may execute an instruction set to control functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the functions described herein.

[0187] At 1405, the UE may receive a first-stage control message from a first UE in a sidelink control channel, where the first-stage control information indicates an estimated resource element overhead. The operation of 1405 may be performed according to the methods described herein. In some examples, aspects of the operation of 1405 may be performed by a two-stage control manager as described with reference to Figures 5 to 8 described (e.g., using a receiver or transceiver).

[0188] At 1410, the UE may receive a second-stage control message from the first UE in a sidelink shared channel. The operation of 1410 may be performed according to the methods described herein. In some examples, aspects of the operation of 1410 may be performed by a two-stage control manager as described with reference to Figures 5 to 8 described (e.g., using a receiver or transceiver).

[0189] At 1415, the UE may receive an encoded data message from the first UE in a sidelink shared channel. The operation of 1415 may be performed according to the methods described herein. In some examples, aspects of the operation of 1415 may be performed by a two-stage control manager as described with reference to Figures 5 to 8 described (e.g., using a receiver or transceiver).

[0190] At 1420, the UE may decode the encoded data message according to the TBS based on the estimated RE overhead associated with the second-phase control message, where the estimated RE overhead is different from the actual RE overhead for the second-phase control message. The operation of 1420 may be performed according to the methods described herein. In some examples, aspects of the operation of 1420 may be performed by a two-phase control manager as described with reference to Figures 5 to 8 (e.g., using a receiver or transceiver).

[0191] The following examples are given by way of illustration. Aspects of the following examples may be combined with aspects shown or discussed elsewhere in the figures or herein.

[0192] An overview of aspects of the present disclosure is provided below:

[0193] Aspect 1: A method for wireless communication at a first UE, including: encoding a data message according to a TBS based at least in part on an estimated RE overhead associated with a control message, where the estimated RE overhead is different from the actual RE overhead for the control message; and transmitting the encoded data message to a second UE.

[0194] Aspect 2: The method of aspect 1, where the control message and the encoded data message are transmitted in a sidelink shared channel.

[0195] Aspect 3: The method of any one of aspects 1 or 2, where the control message schedules the transmission of the encoded data message.

[0196] Aspect 4: The method of any one of aspects 1 to 3, where the estimated RE overhead is defined per PRB or per channel.

[0197] Aspect 5: The method of any one of aspects 1 to 4, where the TBS includes a first TBS, and the method further includes: determining a second RE overhead based at least in part on one or both of the actual RE overhead for the control message or an overhead value indicated in control information; and determining a second TBS based at least in part on the second RE overhead.

[0198] Aspect 6: The method of aspect 5, where determining the second TBS further includes: determining the number of available REs for the sidelink shared channel; and subtracting the second RE overhead from the number of available REs to obtain an updated number of available REs for the sidelink shared channel, where the second TBS is determined based at least in part on the updated number of available REs.

[0199] Aspect 7: The method of any one of aspects 1 to 6, where the estimated RE overhead includes a preconfigured value.

[0200] Aspect 8: The method of any one of Aspects 1 to 6, wherein the control message includes a second-phase control message, and the method further includes: transmitting a first-phase control message to a second UE in a sidelink control channel, wherein the first-phase control information indicates the estimated RE overhead; and transmitting a second-phase control message to the second UE in a sidelink shared channel.

[0201] Aspect 9: The method of any one of Aspects 1 to 8, wherein encoding the data message further includes: determining the number of modulation symbols for the control message at least partially based on the TBS, wherein the data message is encoded according to the number of modulation symbols.

[0202] Aspect 10: A method for wireless communication at a second UE, including: receiving an encoded data message from a first UE; and decoding the encoded data message according to a TBS that is at least partially based on the estimated RE overhead associated with the control message, wherein the estimated RE overhead is different from the actual RE overhead for the control message.

[0203] Aspect 11: The method of Aspect 10, wherein the control message and the encoded data message are received in a sidelink shared channel.

[0204] Aspect 12: The method of any one of Aspects 10 to 11, wherein the encoded data message is decoded at least partially based on information decoded from the control message.

[0205] Aspect 13: The method of any one of Aspects 10 to 12, wherein the estimated RE overhead is defined per physical resource block or per channel.

[0206] Aspect 14: The method of any one of Aspects 10 to 13, wherein the TBS includes a first TBS, and the method further includes: determining a second RE overhead at least partially based on one or both of the actual RE overhead for the control message or the overhead value indicated in the control message; and determining a second TBS at least partially based on the second RE overhead.

[0207] Aspect 15: The method of Aspect 14, wherein determining the second TBS further includes: determining the number of available REs for the sidelink shared channel; and subtracting the second RE overhead from the number of available REs to obtain an updated number of available REs for the sidelink shared channel, wherein the second TBS is determined at least partially based on the updated number of available REs.

[0208] Aspect 16: The method of any one of Aspects 10 to 15, wherein the estimated RE overhead includes a preconfigured value.

[0209] Aspect 17: The method as in any one of Aspects 10 to 15, wherein the control message includes a second-phase control message, and the method further includes: receiving, in a sidelink control channel, a first-phase control message from a first UE, wherein the first-phase control information indicates the estimated RE overhead; and receiving, in a sidelink shared channel, a second-phase control message from the first UE.

[0210] Aspect 18: The method as in any one of Aspects 10 to 17, wherein decoding the encoded data message further includes: determining, at least in part based on the TBS, the number of modulation symbols for the control message, wherein the encoded data message is decoded according to the number of modulation symbols.

[0211] Aspect 19: A system or apparatus for wireless communication at a first UE, including one or more processors; a memory coupled to the one or more processors; and instructions stored in the memory and executable by the one or more processors to cause the system or apparatus to implement the method as in any one of Aspects 1 to 9.

[0212] Aspect 20: A system or device for wireless communication at a first UE, including at least one means for implementing the method as in any one of Aspects 1 to 9 or a device for implementing the method as in any one of Aspects 1 to 9.

[0213] Aspect 21: A non-transitory computer-readable medium storing code for wireless communication at a first UE, the code including instructions executable by one or more processors to cause the one or more processors to implement the method as in any one of Aspects 1 to 9.

[0214] Aspect 22: A system or apparatus for wireless communication at a second UE, including one or more processors; a memory coupled to the one or more processors; and instructions stored in the memory and executable by the one or more processors to cause the system or apparatus to implement the method as in any one of Aspects 10 to 18.

[0215] Aspect 23: A system or device for wireless communication at a second UE, including at least one means for implementing the method as in any one of Aspects 10 to 18 or a device for implementing the method as in any one of Aspects 1 to 18.

[0216] Aspect 24: A non-transitory computer-readable medium storing code for wireless communication at a second UE, the code including instructions executable by one or more processors to cause the one or more processors to implement the method as in any one of Aspects 10 to 18.

[0217] Aspects of these examples can be combined with aspects or embodiments disclosed in other implementations. Further, it should be noted that the methods described herein describe possible implementations, and the operations and steps can be rearranged or otherwise modified and other implementations are possible. In addition, aspects from two or more methods can be combined.

[0218] Although aspects of LTE, LTE-A, LTE-A Pro, or NR systems may be described for example purposes and the LTE, LTE-A, LTE-A Pro, or NR terms may be used in most of the description, the techniques described herein can also be applied to networks other than LTE, LTE-A, LTE-A Pro, or NR networks. For example, the described techniques can 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.

[0219] The information and signals described herein can 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 can be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or optical particles, or any combination thereof.

[0220] The various illustrative blocks and components described in connection with the disclosure herein can be implemented or performed with a general-purpose processor, DSP, ASIC, CPU, 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 can be a microprocessor, but in the alternative, the processor can be any processor, controller, microcontroller, or state machine. The processor can 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).

[0221] 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 executed by a processor, hardware, firmware, hardwiring, or any combination thereof. 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.

[0222] 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 purpose or special purpose computer. By way of example, and not limitation, non-transitory computer-readable media can 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 means in the form of instructions or data structures and that can be accessed by a general purpose or special purpose computer, or a general purpose or special purpose processor. Likewise, 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, digital subscriber line (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, the terms “disk” and “disc” include CD, laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Blu-ray disc, where disks usually 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.

[0223] As used herein (including in the claims), the term “or” in a list of items (e.g., a list of items accompanied by phrases 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 referring to a closed set of conditions. For example, an example step described as “based on condition A” can 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 construed in the same manner as the phrase “at least partially based on”.

[0224] 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 numeral 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.

[0225] The description set forth herein in connection with the drawings describes exemplary configurations and does not represent all examples that may be implemented or fall within the scope of the claims. The term "exemplary" 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.

[0226] 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 those 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 first user equipment (UE), comprising: Transmitting a first stage control message to a second UE via a sidelink control channel; Encoding a data message according to a transport block size that is at least partially based on an estimated resource element overhead associated with a second stage control message, wherein the estimated resource element overhead is different from an actual resource element overhead for the second stage control message, and wherein the estimated resource element overhead is calculated at least partially based on a number of information bits for the second stage control message, a number of error correction bits for the second stage control message, and a predetermined value associated with the second stage control message; and Transmitting the encoded data message and the second stage control message to the second UE via a sidelink shared channel.

2. The method of claim 1, wherein the second stage control message schedules transmission of the encoded data message.

3. The method of claim 1, wherein the estimated resource element overhead is defined per physical resource block or per channel.

4. The method of claim 1, wherein the transport block size includes a first transport block size, and the method further comprises: Determining a second resource element overhead based at least partially on one or both of the actual resource element overhead for the second stage control message or an overhead value indicated in the second stage control message; and Determining a second transport block size based at least partially on the second resource element overhead.

5. The method of claim 4, wherein determining the second transport block size further comprises: Determining a number of available resource elements for the sidelink shared channel; And Subtracting the second resource element overhead from the number of available resource elements to obtain an updated number of the available resource elements for the sidelink shared channel, wherein the second transport block size is determined at least partially based on the updated number of available resource elements.

6. The method of claim 1, wherein the first stage control information indicates the estimated resource element overhead.

7. The method of claim 1, wherein encoding the data message further comprises: Determining a number of modulation symbols for the second stage control message based at least partially on the transport block size, wherein the data message is encoded according to the number of modulation symbols.

8. A method for wireless communication at a second user equipment (UE), comprising: Receiving a first stage control message from a first UE via a sidelink control channel; Receiving an encoded data message and a second stage control message from the first UE via a sidelink shared channel; And Decode the encoded data message according to a transport block size that is at least partially based on an estimated resource element overhead associated with the second-phase control message, wherein the estimated resource element overhead is different from an actual resource element overhead for the second-phase control message, and wherein the estimated resource element overhead is calculated at least partially based on a number of information bits for the second-phase control message, a number of error correction bits for the second-phase control message, and a predetermined value associated with the second-phase control message.

9. The method of claim 8, wherein the encoded data message is decoded at least partially based on information decoded from the second-phase control message.

10. The method of claim 8, wherein the estimated resource element overhead is defined per physical resource block or per channel.

11. The method of claim 8, wherein the transport block size includes a first transport block size, and the method further includes: Determining a second resource element overhead at least partially based on one or both of an actual resource element overhead for the second-phase control message or an overhead value indicated in the second-phase control message; and Determining a second transport block size at least partially based on the second resource element overhead.

12. The method of claim 11, wherein determining the second transport block size further includes: Determining a number of available resource elements for the sidelink shared channel; And Subtracting the second resource element overhead from the number of available resource elements to obtain an updated number of available resource elements for the sidelink shared channel, wherein the second transport block size is determined at least partially based on the updated number of available resource elements.

13. The method of claim 8, wherein the first-phase control information indicates the estimated resource element overhead.

14. The method of claim 8, wherein decoding the encoded data message further includes: Determining a number of modulation symbols for the second-phase control message at least partially based on the transport block size, wherein the encoded data message is decoded according to the number of modulation symbols.

15. A first user equipment (UE) comprising: One or more memories storing processor-executable code; And One or more processors coupled to the one or more memories and configured to execute the code to cause the first UE to: Transmit a first-phase control message to a second UE via a sidelink control channel; Encode a data message according to a transport block size that is at least partially based on an estimated resource element overhead associated with a second-phase control message, where the estimated resource element overhead is different from an actual resource element overhead for the second-phase control message, and where the estimated resource element overhead is calculated based at least in part on a number of information bits for the second-phase control message, a number of error correction bits for the second-phase control message, and a predetermined value associated with the second-phase control message; and Transmit the encoded data message and the second-phase control message to the second UE via a sidelink shared channel.

16. The first UE according to claim 15, wherein the second-phase control message schedules transmission of the encoded data message.

17. The first UE according to claim 15, wherein the estimated resource element overhead is defined per physical resource block or per channel.

18. The first UE according to claim 15, wherein the first-phase control information indicates the estimated resource element overhead.

19. A second user equipment (UE) comprising: One or more memories that store processor-executable code; And One or more processors coupled to the one or more memories and configured to execute the code to cause the second UE to: Receive a first-phase control message from a first UE via a sidelink control channel; Receive an encoded data message and a second-phase control message from the first UE via a sidelink shared channel; And Decode the encoded data message according to a transport block size that is at least partially based on an estimated resource element overhead associated with the second-phase control message, where the estimated resource element overhead is different from an actual resource element overhead for the second-phase control message, and where the estimated resource element overhead is calculated based at least in part on a number of information bits for the second-phase control message, a number of error correction bits for the second-phase control message, and a predetermined value associated with the second-phase control message.

20. The second UE according to claim 19, wherein the encoded data message is decoded at least in part based on information decoded from the second-phase control message.

21. The second UE according to claim 19, wherein the estimated resource element overhead is defined per physical resource block or per channel.

22. The second UE according to claim 19, wherein the first-phase control information indicates the estimated resource element overhead.

Images