TRANSPORT BLOCK SIZE DETERMINATION FOR SIDELINK COMMUNICATIONS

Methods, systems, and devices for wireless communications are described. A communication device, which may be otherwise known as user equipment (UE) may support direct communications with other communications devices (e.g., direct communications between multiple UEs). Direct communications may include, but are not limited to, device-to-device (D2D) communications, vehicle-based communications, which may also be referred to as vehicle-to-everything (V2X) communications, vehicle-to-vehicle (V2V) communications, and the like. In an example of V2X communications, V2V communications, and the like, a UE may identify sidelink information for sidelink communications, encode the sidelink information for the sidelink communications based on a transport block size (TBS), determine the TBS for the sidelink information based on an overhead size of a second physical sidelink channel for communicating the sidelink information, and transmit the sidelink information on a physical sidelink channel.

INTRODUCTION

The following relates to wireless communications, and more specifically to direct communications between communications devices in wireless communications systems.

A wireless multiple-access communications system may include one or more base stations or one or more network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE). Some wireless communications systems may support direct communications between communications devices (e.g., direct communications between multiple UEs). Examples of direct communications may include device-to-device (D2D) communications, vehicle-based communications, which may also be referred to as vehicle-to-everything (V2X) communications, vehicle-to-vehicle (V2V) communications, and the like. As demand for communication efficiency increases, it may be desirable for some wireless communications systems to improve direct communication operations, for example, improve reliability or latency of direct communications, among other examples.

SUMMARY

A method for wireless communication is described. The method may include encoding sidelink information for sidelink communications based on a transport block size (TBS), and transmitting the encoded sidelink information on a physical sidelink channel, the TBS based on an overhead of a second physical sidelink channel for communicating the sidelink information.

An apparatus for wireless communication is described. The apparatus may include a processor, memory coupled to the processor, the processor and memory configured to encode sidelink information for sidelink communications based on a TBS, and transmit the encoded sidelink information on a physical sidelink channel, the TBS based on an overhead of a second physical sidelink channel for communicating the sidelink information.

Another apparatus for wireless communication is described. The apparatus may include means for encoding sidelink information for sidelink communications based on a TBS, and transmitting the encoded sidelink information on a physical sidelink channel, the TBS based on an overhead of a second physical sidelink channel for communicating the sidelink information.

A non-transitory computer-readable medium storing code for wireless communication is described. The code may include instructions executable by a processor to encode sidelink information for sidelink communications based on a TBS, and transmit the encoded sidelink information on a physical sidelink channel, the TBS based on an overhead of a second physical sidelink channel for communicating the sidelink information.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining an estimate number of REs associated with a physical resource block for sidelink communications and where the TBS may be based on the estimate number of REs associated with the physical resource block.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a number of allocated physical resource blocks for the sidelink communications, determining a number of REs associated with the allocated physical resource blocks for the sidelink communications based on the number of allocated physical resource blocks or the estimate number of REs associated with the physical resource block, or both, and where the TBS may be based on the number of REs associated with the allocated physical resource blocks for the sidelink communications.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting signaling including an indication of a number of symbols to use for the TBS determination and where the TBS may be based on the signaling.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a number of allocated symbols associated with the physical sidelink channel, the physical sidelink channel including a physical sidelink control channel, subtracting the number of symbols to use for the TBS determination from the number of allocated symbols associated with the physical sidelink channel, and where determining the estimate number of REs associated with the physical resource block may be based on the subtracting.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining the estimate number of REs associated with the physical resource block may be based on the number of symbols to use for the TBS determination.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a number of REs for a first sidelink control information, subtracting the number of REs for the first sidelink control information from the number of REs associated with the allocated physical resource blocks, and where the TBS may be based on the subtracting.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the sidelink information on the physical sidelink channel may include operations, features, means, or instructions for transmitting the first sidelink control information on a physical sidelink control channel based on the TBS.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining that a first physical sidelink channel and the second physical sidelink channel may be frequency division multiplexed, the first physical sidelink channel includes a physical sidelink shared channel and the second physical sidelink channel includes a physical sidelink control channel and where the TBS may be based on that the first physical sidelink channel and the second physical sidelink channel may be frequency division multiplexed.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining that the physical sidelink shared channel occupies the number of REs associated with the allocated physical resource blocks and adjusting an overhead of the physical sidelink control channel based at least in part on a value of the number of REs occupied by the physical sidelink shared channel, where the overhead of the physical sidelink control channel may be per slot.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining that a first physical sidelink channel and the second physical sidelink channel may be time division multiplexed, the first physical sidelink channel includes a physical sidelink shared channel and the second physical sidelink channel includes a physical sidelink control channel and where the TBS may be based on determining that the first physical sidelink channel and the second physical sidelink channel may be time division multiplexed.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining an overhead of the physical sidelink control channel per physical resource block based on determining that the first physical sidelink channel and the second physical sidelink channel may be time division multiplexed and where the TBS may be based on the overhead of the physical sidelink control channel being per physical resource block.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a number of symbols associated with the physical sidelink control channel or the physical sidelink shared channel, or both, determining a number of symbols exclusively including the physical sidelink control channel, excluding the number of symbols exclusively including the physical sidelink control channel from the estimate number of REs associated with the physical resource block or the number of REs associated with the allocated physical resource blocks, or both, and where the TBS may be based on the excluding.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the TBS may be based on the overhead of the physical sidelink control channel being per slot.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a number of REs for a second sidelink control information, subtracting the number of REs for the second sidelink control information from the estimate number of REs associated with the physical resource block or the number of REs associated with the allocated physical resource blocks, or both, and where the TBS may be based on the subtracting.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a control overhead associated with the second sidelink control information based on a target code rate associated with a modulation coding scheme and where the TBS may be based on the control overhead associated with the second sidelink control information.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a control overhead associated with the second sidelink control information, ignoring the control overhead associated with the second sidelink control information, and where the TBS may be based on ignoring the control overhead associated with the second sidelink control information.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying a modulation coding scheme for the sidelink communications, identifying a target code rate based on the modulation coding scheme for the sidelink communications, and where determining the number of REs for the second sidelink control information may be based on the target code rate.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the sidelink information on the physical sidelink channel may include operations, features, means, or instructions for transmitting the second sidelink control information on a physical sidelink shared channel based on the TBS.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting signaling including an indication of an overhead value and where determining the estimate number of REs associated with the physical resource block may be based on the signaled overhead value.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting signaling including an indication of an offset overhead value relative to a demodulation reference signal pattern and where determining the estimate number of REs associated with the physical resource block may be based on the signaled offset overhead value.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for adjusting the number of REs associated with the allocated physical resource blocks for the sidelink communications to a number of REs associated with the allocated physical resource blocks for non-sidelink communications.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a channel state information reference signal overhead, refraining from using the channel state information reference signal overhead from determining the estimate number of REs associated with the physical resource block or determining the number of REs associated with the allocated physical resource blocks, or both, and where the TBS may be based on the ignoring.

A method for wireless communication is described. The method may include decoding sidelink information for sidelink communications based on a TBS, and receiving the decoded sidelink information on a physical sidelink channel, the TBS based on an overhead of a second physical sidelink channel for communicating the sidelink information.

An apparatus for wireless communication is described. The apparatus may include a processor, memory coupled with the processor, the processor and memory configured to decode sidelink information for sidelink communications based on a TBS, and receive the decoded sidelink information on a physical sidelink channel, the TBS based on an overhead of a second physical sidelink channel for communicating the sidelink information.

Another apparatus for wireless communication is described. The apparatus may include means for decoding sidelink information for sidelink communications based on a TBS, and receiving the decoded sidelink information on a physical sidelink channel, the TBS based on an overhead of a second physical sidelink channel for communicating the sidelink information.

A non-transitory computer-readable medium storing code for wireless communication is described. The code may include instructions executable by a processor to decode sidelink information for sidelink communications based on a TBS, and receive the decoded sidelink information on a physical sidelink channel, the TBS based on an overhead of a second physical sidelink channel for communicating the sidelink information.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining an estimate number of REs associated with a physical resource block for sidelink communications and where the TBS may be based on the estimate number of REs associated with the physical resource block.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a number of allocated physical resource blocks for the sidelink communications, determining a number of REs associated with the allocated physical resource blocks for the sidelink communications based on the number of allocated physical resource blocks or the estimate number of REs associated with the physical resource block, or both, and where the TBS may be based on the number of REs associated with the allocated physical resource blocks for the sidelink communications.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a number of REs for a first sidelink control information, subtracting the number of REs for the first sidelink control information from the number of REs associated with the allocated physical resource blocks, and where the TBS may be based on the subtracting.

A method of wireless communication is described. The method may include identifying sidelink control information (SCI) for sidelink communications, determining a TBS for the SCI, and transmitting the SCI on a physical sidelink channel based on the TBS.

An apparatus for wireless communication is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to identify SCI for sidelink communications, determine a TBS for the SCI, and transmit the SCI on a physical sidelink channel based on the TBS.

Another apparatus for wireless communication is described. The apparatus may include means for identifying SCI for sidelink communications, determining a TBS for the SCI, and transmitting the SCI on a physical sidelink channel based on the TBS.

A non-transitory computer-readable medium storing code for wireless communication is described. The code may include instructions executable by a processor to identify SCI for sidelink communications, determine a TBS for the SCI, and transmit the SCI on a physical sidelink channel based on the TBS.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining an estimate number of REs associated with a physical resource block (PRB) for the sidelink communications, where determining the TBS may be based on the estimate number of REs associated with the PRB.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a number of allocated PRBs for the sidelink communications, determining a number of REs associated with the PRB for the sidelink communications based on the number of allocated PRBs or the estimate number of REs associated with the PRB, or both, where determining the TBS may be based on the number of REs associated with the PRB for the sidelink communications.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a number of REs for a first SCI, subtracting the number of REs for the first SCI from the estimate number of REs associated with the PRB or the number of REs associated with the PRB, or both, where determining the TBS may be based on the subtracting.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining control overhead associated with the first SCI, refraining from using the control overhead in the estimate number of REs associated with the PRB or the number of REs associated with the PRB, or both, where determining the TBS may be based on the refraining.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the SCI on the physical sidelink channel may include operations, features, means, or instructions for transmitting the first SCI on a physical sidelink control channel (PSCCH) based on the TBS.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining that a first physical sidelink channel and a second physical sidelink channel may be frequency division multiplexed, the first physical sidelink channel includes a physical sidelink shared channel (PSSCH) and the second physical sidelink channel includes a PSCCH, where determining the TBS may be based on that the first physical sidelink channel and the second physical sidelink channel may be frequency division multiplexed.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining that PSSCH occupies the number of REs associated with the PRB, and scaling an overhead of the PSCCH by a value of the REs occupied by the PSSCH.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining the TBS may be based on the overhead of the PSCCH per slot.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining that a first physical sidelink channel and a second physical sidelink channel may be time division multiplexed, the first physical sidelink channel includes a PSSCH and the second physical sidelink channel includes a PSCCH, where determining the TBS may be based on that the first physical sidelink channel and the second physical sidelink channel may be time division multiplexed.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining an overhead of the PSCCH per PRB based on that the first sidelink channel and the second physical sidelink channel may be time division multiplexed, where determining the TBS may be based on the overhead of the PSCCH per PRB.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a number of symbols associated with the PSCCH or the PSSCH, or both, determining a number of symbols exclusively including the PSCCH, excluding the number of symbols exclusively including the PSCCH from the estimate number of REs associated with the PRB or the number of REs associated with the PRB, or both, where determining the TBS may be based on the excluding.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining the TBS may be based on an overhead of the PSCCH per slot.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a number of REs for a second SCI, subtracting the number of REs for the second SCI from the estimate number of REs associated with the PRB or the number of REs associated with the PRB, or both, where determining the TBS may be based on the subtracting.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a control overhead associated with the second SCI based on a target code rate associated with a modulation coding scheme, where determining the TBS may be based on the control overhead associated with the second SCI.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for ignoring the control overhead associated with the second SCI, where determining the TBS may be based on ignoring the control overhead associated with the second SCI.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying a modulation coding scheme for the second SCI, identifying a target code rate based on the modulation coding scheme for second SCI, where determining the number of REs for the second SCI may be based on the target code rate.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the SCI on the physical sidelink channel may include operations, features, means, or instructions for transmitting the second SCI on a PSSCH based on the TBS.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting signaling including an indication of an overhead value, where determining the estimate number of REs associated with the PRB may be based on the signaled overhead value.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting signaling including an indication of an offset overhead value relative to a demodulation reference signal pattern, where determining the estimate number of REs associated with the PRB may be based on the signaled offset overhead value.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting signaling including an indication of a number of symbols to use for the TBS determination, where determining the TBS may be based on the signaling.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a number of allocated symbols associated with the physical sidelink channel, the physical sidelink channel including a PSCCH, subtracting the number of symbols to use for the TBS determination from the number of allocated symbols associated with the physical sidelink channel, where determining the estimate number of REs associated with the PRB may be based on the subtracting.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining the estimate number of REs associated with the PRB may be based on the number of symbols to use for the TBS determination.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for adjusting the number of REs associated with the PRB for the sidelink communications to a number of REs associated with the PRB for non-sidelink communications.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a channel state information reference signal overhead, refraining from using the channel state information reference signal overhead from determining the estimate number of REs associated with the PRB or determining the number of REs associated with the PRB, or both, where determining the TBS may be based on the ignoring.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a number of subcarriers associated with the PRB, where determining the estimate number of REs associated with the PRB may be based on the number of subcarriers associated with the PRB.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a number of allocated symbols associated with a physical sidelink channel, where determining the estimate number of REs associated with the PRB may be based on one or more of the number of subcarriers associated with the PRB and the number of allocated symbols associated with the physical sidelink channel.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a demodulation reference signal overhead associated with the PRB, where determining the estimate number of REs associated with the PRB may be based on the reference signal overhead associated with the PRB.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining control overhead associated with the PRB, where determining the estimate number of REs associated with the PRB may be based on the control overhead associated with the PRB.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining an overhead of the physical sidelink channel based on a period of the physical sidelink channel, where determining the TBS may be based on the overhead of the physical sidelink channel.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the physical sidelink channel includes a physical sidelink feedback channel.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for scaling the overhead of the physical sidelink channel based on the period of the physical sidelink channel, where determining the TBS may be based on the scaling.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining an average of the overhead of the physical sidelink channel over the period of the physical sidelink channel, where determining the TBS may be based on the average of the overhead of the physical sidelink channel over the period of the physical sidelink channel.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for applying the overhead of the physical sidelink channel as a value per PRB, where determining the TBS may be based on the applying.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the overhead of the physical sidelink channel corresponds to a number of available symbols of a second physical sidelink channel, the second physical sidelink channel including a PSSCH.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the physical sidelink channel includes a PSSCH.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the physical sidelink channel includes a PSCCH.

A method of wireless communication is described. The method may include identifying SCI for sidelink communications, determining a TBS for the SCI, and receiving the SCI on a physical sidelink channel based on the TBS.

An apparatus for wireless communication is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to identify SCI for sidelink communications, determine a TBS for the SCI, and receive the SCI on a physical sidelink channel based on the TBS.

Another apparatus for wireless communication is described. The apparatus may include means for identifying SCI for sidelink communications, determining a TBS for the SCI, and receiving the SCI on a physical sidelink channel based on the TBS.

A non-transitory computer-readable medium storing code for wireless communication is described. The code may include instructions executable by a processor to identify SCI for sidelink communications, determine a TBS for the SCI, and receive the SCI on a physical sidelink channel based on the TBS.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining an estimate number of REs associated with a physical resource block (PRB) for the sidelink communications, where determining the TBS may be based on the estimate number of REs associated with the PRB.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a number of allocated PRBs for the sidelink communications, determining a number of REs associated with the PRB for the sidelink communications based on the number of allocated PRBs or the estimate number of REs associated with the PRB, or both, where determining the TBS may be based on the number of REs associated with the PRB for the sidelink communications.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a number of REs for a first SCI, subtracting the number of REs for the first SCI from the estimate number of REs associated with the PRB or the number of REs associated with the PRB, or both, where determining the TBS may be based on the subtracting.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining control overhead associated with the first SCI, refraining from using the control overhead in the estimate number of REs associated with the PRB or the number of REs associated with the PRB, or both, where determining the TBS may be based on the refraining.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the SCI on the physical sidelink channel may include operations, features, means, or instructions for receiving the first SCI on a PSCCH based on the TBS.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining that a first physical sidelink channel and a second physical sidelink channel may be frequency division multiplexed, the first physical sidelink channel includes a PSSCH and the second physical sidelink channel includes a PSCCH, where determining the TBS may be based on that the first physical sidelink channel and the second physical sidelink channel may be frequency division multiplexed.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining that PSSCH occupies the number of REs associated with the PRB, and scaling an overhead of the PSCCH by a value of the REs occupied by the PSSCH.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining the TBS may be based on the overhead of the PSCCH per slot.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining that a first physical sidelink channel and a second physical sidelink channel may be time division multiplexed, the first physical sidelink channel includes a PSSCH and the second physical sidelink channel includes a PSCCH, where determining the TBS may be based on that the first physical sidelink channel and the second physical sidelink channel may be time division multiplexed.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining an overhead of the PSCCH per PRB based on that the first sidelink channel and the second physical sidelink channel may be time division multiplexed, where determining the TBS may be based on the overhead of the PSCCH per PRB.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a number of symbols associated with the PSCCH or the PSSCH, or both, determining a number of symbols exclusively including the PSCCH, excluding the number of symbols exclusively including the PSCCH from the estimate number of REs associated with the PRB or the number of REs associated with the PRB, or both, where determining the TBS may be based on the excluding.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining the TBS may be based on an overhead of the PSCCH per slot.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a number of REs for a second SCI, subtracting the number of REs for the second SCI from the estimate number of REs associated with the PRB or the number of REs associated with the PRB, or both, where determining the TBS may be based on the subtracting.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a control overhead associated with the second SCI based on a target code rate associated with a modulation coding scheme, where determining the TBS may be based on the control overhead associated with the second SCI.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for ignoring the control overhead associated with the second SCI, where determining the TBS may be based on ignoring the control overhead associated with the second SCI.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying a modulation coding scheme for the second SCI, identifying a target code rate based on the modulation coding scheme for second SCI, where determining the number of REs for the second SCI may be based on the target code rate.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the SCI on the physical sidelink channel may include operations, features, means, or instructions for receiving the second SCI on a PSSCH based on the TBS.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving signaling including an indication of an overhead value, where determining the estimate number of REs associated with the PRB may be based on the signaled overhead value.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving signaling including an indication of an offset overhead value relative to a demodulation reference signal pattern, where determining the estimate number of REs associated with the PRB may be based on the signaled offset overhead value.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving signaling including an indication of a number of symbols to use for the TBS determination, where determining the TBS may be based on the signaling.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a number of allocated symbols associated with the physical sidelink channel, the physical sidelink channel including a PSCCH, subtracting the number of symbols to use for the TBS determination from the number of allocated symbols associated with the physical sidelink channel, where determining the estimate number of REs associated with the PRB may be based on the subtracting.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining the estimate number of REs associated with the PRB may be based on the number of symbols to use for the TBS determination.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for adjusting the number of REs associated with the PRB for the sidelink communications to a number of REs associated with the PRB for non-sidelink communications.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a channel state information reference signal overhead, refraining from using the channel state information reference signal overhead from determining the estimate number of REs associated with the PRB or determining the number of REs associated with the PRB, or both, where determining the TBS may be based on the ignoring.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a number of subcarriers associated with the PRB, where determining the estimate number of REs associated with the PRB may be based on the number of subcarriers associated with the PRB.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a number of allocated symbols associated with a physical sidelink channel, where determining the estimate number of REs associated with the PRB may be based on one or more of the number of subcarriers associated with the PRB and the number of allocated symbols associated with the physical sidelink channel.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a demodulation reference signal overhead associated with the PRB, where determining the estimate number of REs associated with the PRB may be based on the reference signal overhead associated with the PRB.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining control overhead associated with the PRB, where determining the estimate number of REs associated with the PRB may be based on the control overhead associated with the PRB.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining an overhead of the physical sidelink channel based on a period of the physical sidelink channel, where determining the TBS may be based on the overhead of the physical sidelink channel.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the physical sidelink channel includes a physical sidelink feedback channel.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for scaling the overhead of the physical sidelink channel based on the period of the physical sidelink channel, where determining the TBS may be based on the scaling.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining an average of the overhead of the physical sidelink channel over the period of the physical sidelink channel, where determining the TBS may be based on the average of the overhead of the physical sidelink channel over the period of the physical sidelink channel.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for applying the overhead of the physical sidelink channel as a value per PRB, where determining the TBS may be based on the applying.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the overhead of the physical sidelink channel corresponds to a number of available symbols of a second physical sidelink channel, the second physical sidelink channel including a PSSCH.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the physical sidelink channel includes a PSSCH.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the physical sidelink channel includes a PSCCH.

A method of wireless communication is described. The method may include allocating resources for sidelink communications on a physical sidelink channel, transmitting, based on the allocating, signaling including an indication of the resources for the sidelink communications, and receiving SCI on the physical sidelink channel based on the signaling, where TBS for the SCI is determined based on the indication of the resources for the sidelink communications.

An apparatus for wireless communication is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to allocate resources for sidelink communications on a physical sidelink channel, transmit, based on the allocating, signaling including an indication of the resources for the sidelink communications, and receive SCI on the physical sidelink channel based on the signaling, where TBS for the SCI is determined based on the indication of the resources for the sidelink communications.

Another apparatus for wireless communication is described. The apparatus may include means for allocating resources for sidelink communications on a physical sidelink channel, transmitting, based on the allocating, signaling including an indication of the resources for the sidelink communications, and receiving SCI on the physical sidelink channel based on the signaling, where TBS for the SCI is determined based on the indication of the resources for the sidelink communications.

A non-transitory computer-readable medium storing code for wireless communication is described. The code may include instructions executable by a processor to allocate resources for sidelink communications on a physical sidelink channel, transmit, based on the allocating, signaling including an indication of the resources for the sidelink communications, and receive SCI on the physical sidelink channel based on the signaling, where TBS for the SCI is determined based on the indication of the resources for the sidelink communications.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the signaling may include operations, features, means, or instructions for transmitting signaling including an indication of an overhead value, where an estimate number of REs associated with a PRB for the sidelink communications may be based on the signaled overhead value.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the signaling may include operations, features, means, or instructions for transmitting signaling including an indication of a number of symbols to use for the TBS determination, where the TBS may be based on the number of symbols to use for the TBS determination.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the physical sidelink channel includes a PSSCH.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the physical sidelink channel includes a PSCCH.

DETAILED DESCRIPTION

Wireless communications systems may include multiple communication devices such as UEs and base stations, which may provide wireless communication services to the UEs. For example, such base stations may be next-generation NodeBs or giga-NodeBs (either of which may be referred to as a gNB) that may support multiple radio access technologies including 4G systems, such as LTE systems, as well as 5G systems, which may be referred to as NR systems. Some wireless communications systems may also provide direct communications between multiple UEs. Examples of direct communications may include, but are not limited to, D2D communications, vehicle-based communications, which may also be referred to as V2X communications systems, V2V communications systems, etc. In an example of a V2X communication system or a V2V communication system, a vehicle may communicate SCI and sidelink data to indicate to other vehicles information relevant to the other vehicles. For example, a UE may indicate to other UEs in the V2X or V2V system, resources in time and frequency that are occupied by the UE. In some cases, UEs (e.g., vehicles) in these communication systems may less effectively communicate the SCI or the sidelink data, or both due to a change in time and frequency resources of the communication systems among other factors.

As demand for communication efficiency increases, in some wireless communications systems, it may be desirable to provide satisfactory direct communications, and as a result, support high reliability or low latency direct communications, among other examples. The described techniques may be used to configure UEs to determine TBS for SCI and sidelink data in wireless communication systems that support direct communications, such as in V2X communications systems, V2V communications systems, etc. For example, various aspects of the described techniques relate to configuring UEs to determine a TBS for direct communications, such as sidelink communications and such systems may benefit from improved techniques for TBS determination for sidelink communications which may provide for flexible TB S determination under a number of conditions or in a number of situations as described herein. For example, a vehicle in a V2X communication system may determine a TBS to transmit an SCI message (e.g., an SCI-1, an SCI-2) over a PSCCH or a PSSCH, or both to other vehicles under a number of conditions or in a number of situations where the TBS may be the same for an initial transmission and a re-transmission of a same transport block.

For example, various aspects of the described techniques relate to configuring one or more UEs to determine a TBS for sidelink communications when a demodulation reference signal (DMRS) pattern is dynamically-indicated. In some other examples, various aspects of the described techniques relate to configuring one or more UEs to determine a TBS for sidelink communications depending on a presence or an absence of a physical sidelink feedback channel (PSFCH). In other examples, various aspects of the described techniques relate to configuring one or more UEs to determine a TBS for sidelink communications depending on a second stage control (SCI-2) (e.g., based on a modulation and coding scheme (MCS) and a scaling factor). In some other examples, various aspects of the described techniques relate to configuring one or more UEs to determine a TBS for sidelink communications depending on CSI-RS. In other words, various aspects of the described techniques may account for changing conditions in which a UE may transmit sidelink information and flexible determination of TBS may enhance reliability under such conditions.

In some examples, the TBS for sidelink communications may be determined based on an overhead of a physical sidelink channel. For example, the TBS may be determined based on an overhead (e.g., resource elements dedicated to control, signaling, or synchronization tasks, among other examples, at the physical layer) associated with a physical sidelink control channel (PSCCH) or a physical sidelink shared channel (PSSCH). For example, the TBS may be determined based on an overhead of the PSCCH on a per-PRB basis or, as another example on a per-slot basis, among other examples.

Particular aspects of the subject matter described in this disclosure may be implemented to realize one or more of the following potential advantages, among others. The techniques employed by UEs may provide benefits and enhancements to the operation of the UEs. For example, operations performed by the UEs may provide improvements to sidelink operations. In some examples, configuring the UEs to support TBS determination for sidelink communications may support improvements to power consumption, spectral efficiency, higher data rates and, in some examples, may promote enhanced efficiency for sidelink communication operations, among other benefits.

Aspects of the disclosure are initially described in the context of wireless communications systems. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to TBS determination for sidelink communications.

The base stations105may communicate with the core network130, or with one another, or both. For example, the base stations105may interface with the core network130through one or more backhaul links120(e.g., via an S1, N2, N3, or other interface). The base stations105may communicate with one another over the backhaul links120(e.g., via an X2, Xn, or other interface) either directly (e.g., directly between base stations105), or indirectly (e.g., via core network130), or both. In some examples, the backhaul links120may be or include one or more wireless links. A UE115may communicate with the core network130through a communication link155. One or more of the base stations105described herein may include or may be referred to by a person having ordinary skill in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB), a next-generation NodeB or a giga-NodeB (either of which may be referred to as a gNB), a Home NodeB, a Home eNodeB, or other suitable terminology.

Signal waveforms transmitted over a carrier may be made up of multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)). In a system employing MCM techniques, a RE may consist of one symbol period (e.g., a duration of one modulation symbol) and one subcarrier, e.g., with a PRB, where the symbol period and subcarrier spacing are inversely related and the PRB may include or consist of a plurality of REs. The number of bits carried by each RE may depend on the modulation scheme (e.g., the order of the modulation scheme, the coding rate of the modulation scheme, or both). Thus, the more REs that a UE115receives and the higher the order of the modulation scheme, the higher the data rate may be for the UE115. A wireless communications resource may refer to a combination of a radio frequency spectrum resource, a time resource, and a spatial resource (e.g., spatial layers or beams), and the use of multiple spatial layers may further increase the data rate or data integrity for communications with a UE115.

One or more numerologies for a carrier may be supported, where a numerology may include a subcarrier spacing (Δf) and a cyclic prefix. A carrier may be divided into one or more BWPs having the same or different numerologies. In some examples, a UE115may be configured with multiple BWPs. In some examples, a single BWP for a carrier may be active at a given time and communications for the UE115may be restricted to one or more active BWPs. The time intervals for the base stations105or the UEs115may be expressed in multiples of a basic time unit which may, for example, refer to a sampling period of Ts=1/(Δfmax·Nf) seconds, where Δfmaxmay represent the maximum supported subcarrier spacing, and Δffmay represent the maximum supported discrete Fourier transform (DFT) size. Time intervals of a communications resource 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).

Each frame may include multiple consecutively numbered subframes or slots, and each subframe or 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 slots. Alternatively, each frame may include a variable number of slots, and the number of slots may depend on subcarrier spacing. Each slot may include a number of symbol periods (e.g., depending on the length of the cyclic prefix prepended to each symbol period). In some wireless communications systems100, a slot may further be divided into multiple mini-slots containing one or more symbols. Excluding the cyclic prefix, each symbol period may contain one or more (e.g., Nf) sampling periods. The duration of a symbol period may depend on the subcarrier spacing or frequency band of operation. A subframe, a slot, a mini-slot, or a symbol may be the smallest scheduling unit (e.g., in the time domain) of the wireless communications system100and 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 communications system100may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs)).

A macro cell covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by the UEs115with service subscriptions with the network provider supporting the macro cell. A small cell may be associated with a lower-powered base station105, as compared with a macro cell, and a small cell may operate in the same or different (e.g., licensed, unlicensed) frequency bands as macro cells. Small cells may provide unrestricted access to the UEs115with service subscriptions with the network provider or may provide restricted access to the UEs115having an association with the small cell (e.g., the UEs115in a closed subscriber group (CSG), the UEs115associated with users in a home or office). A base station105may support one or multiple cells and may also support communications over the one or more cells using one or multiple component carriers. In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., MTC, narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB)) that may provide access for different types of devices.

In some systems, the D2D communication link135may be an example of a communication channel, such as a sidelink communication channel, between vehicles (e.g., UEs115). In some examples, vehicles may communicate using vehicle-to-everything (V2X) communications, vehicle-to-vehicle (V2V) communications, or some combination of these. A vehicle may signal information related to traffic conditions, signal scheduling, weather, safety, emergencies, or any other information relevant to a V2X system. A UE115may identify SCI for sidelink communications, determine a TBS for the SCI, and transmit the SCI on a physical sidelink channel based on the TBS. One or more of these operations may be performed by a UE communications manager101, which may be an example of a UE communications manager515,615,705, or810as described with reference toFIGS. 5 through 8. In some examples, vehicles in a V2X system may communicate with roadside infrastructure, such as roadside units, or with the network via one or more network nodes (e.g., base stations105) using vehicle-to-network (V2N) communications, or with both.

FIG. 2illustrates an example of a wireless communications system200that supports sidelink communications in accordance with one or more aspects of the present disclosure. In some examples, the wireless communications system200may implement aspects of the wireless communications system100. For example, the wireless communications system200may include multiple UEs, such as a UE115-aand a UE115-b, which may be examples of the corresponding devices described with reference toFIG. 1. In some examples, the wireless communications system200may support multiple radio access technologies including 4G systems such as LTE systems, LTE-A systems, or LTE-A Pro systems, and 5G systems which may be referred to as NR systems. The wireless communications system200may support improvements to power consumption, spectral efficiency, higher data rates and, in some examples, may promote enhanced efficiency for high reliability and low latency direct communications operations, among other benefits.

The wireless communications system200may, in some examples, support direct communications between multiple UEs, such as the UE115-aand the UE115-b. For example, the UE115-amay be able to communicate directly with the UE115-b(e.g., other UEs) over a D2D communication link205(e.g., using a P2P or D2D protocol). In some examples, the D2D communication link205may be an example of a communication channel, such as a sidelink communication channel, between vehicles (e.g., UEs115). The sidelink communication channel may correspond to a PC5 interface between the UE115-aand the UE115-b. The PC5 interface may facilitate direct communications between at least two UEs without involving a network infrastructure (e.g., a base station (e.g., an eNB, a next-generation NodeB or giga-NodeB (either of which may be referred to as a gNB), and the like). The PC5 interface may also be a one-to-many communication interface (i.e., may be specified for group communications).

In some examples, multiple vehicles (e.g., the UE115-a, the UE115-b) may communicate using V2X communications, V2V communications, or some combination of these. A vehicle may signal information related to traffic conditions, signal scheduling, weather, safety, emergencies, or any other information relevant to a V2X communication system. For example, the UE115-amay signal SCI and sidelink data relevant to a V2X communication system to the UE115-busing one or more physical sidelink channels. Examples of physical sidelink channels may include a PSCCH and a PSSCH. In some examples, vehicles in a V2X communication system may communicate with roadside infrastructure, such as roadside units, or with a network via one or more network nodes (e.g., base stations105) using vehicle-to-network (V2N) communications, or with both. An example of a physical layer structure for direct communications, such as sidelink communications is described with reference toFIG. 3.

FIG. 3illustrates an example of a block diagram300that supports sidelink communications in accordance with one or more aspects of the present disclosure. The block diagram300may implement aspects of the wireless communications system100and200described with reference toFIGS. 1 and 2, respectively. For example, the block diagram300may be based on a configuration by a UE115, and implemented by the UE115. In the example illustrated inFIG. 3, the block diagram300may be applicable to implementations or instances when the UE115is configured with direct communication operations, such as sidelink communication operations in V2X and V2V communication systems. For example, the block diagram300may include a PSCCH305and a PSSCH310, which may correspond to time resources (for example, a symbol, a minislot, a slot, a subframe, a frame), as well as frequency resources (for example, subcarriers, carriers). In some examples, the PSCCH305may correspond to a number of symbols in a time domain, for example, such as two or three symbols. Similarly, the PSSCH310may correspond to a number of symbols in a time domain.

The PSCCH305may be associated with the PSSCH310. In some examples, the PSCCH305and the PSSCH310may be frequency division multiplexed and transmitted (and/or received) in a same time resource (e.g., a slot). In some other examples, the PSCCH305and the PSSCH310may be time division multiplexed and transmitted (and/or received) in a same frequency resource (e.g., a subchannel). With reference toFIG. 2, in the example of direct communications, vehicles may communicate using V2X communications, V2V communications, or some combination of these according to time and frequency resources of a resource pool (also referred to as a sidelink resource pool). The resource pool may be divided over one or more of time resources or frequency resources for direct communications between the UE115-aand the UE115-b, for example, such as sidelink communications. The time resources of the resource pool may be divided into slots, and the frequency resources of the resource pool may be divided into subchannels.

In the example illustrated inFIG. 3, the PSCCH305may span a single subchannel315, while the PSSCH310may span multiple subchannels315. A subchannel315may occupy a number of physical resource blocks (PRBs). For example, a subchannel315may occupy10PRBs,15PRBs,20PRBs,25PRBs,50PRBs,75PRBs, or100PRBs. The PSCCH305may also occupy a number of PRBs. For example, the PSCCH305may occupy10PRBs,12PRBs,15PRBs,20PRBs, or25PRBs. When the PSCCH305and a subchannel315occupy a same number of PRBs, and the PSCCH305spans a single subchannel315, the PSCCH305and the PSSCH310may be time division multiplexed.

Returning toFIG. 2, in some examples, a vehicle (e.g., the UE115-a) in a V2X communication system may communicate sidelink information such as SCI, which may carry information that other vehicles (e.g., the UE115-b) may use in order to receive sidelink data (e.g., information related to traffic conditions, signal scheduling, weather, safety, emergencies, or any other information relevant to a V2X communication system) from the vehicle. For example, the vehicle (e.g., the UE115-a) in the V2X communication system may transmit (or receive) an SCI message on a PSCCH, and the SCI message may include information about resource allocation of a PSSCH, which carries sidelink data. In some examples, transmission of the SCI may include multiple stages. For example, a vehicle (e.g., the UE115-a) in a V2X communication system may transmit (or receive) a first SCI (SCI-1) on a PSCCH and a second SCI (SCI-2) on a PSSCH to another vehicle (e.g., the UE115-b). In some examples, a vehicle (e.g., the UE115-a) in a V2X communication system may map contiguous RBs of the SCI-2 in a frequency domain before mapping contiguous RBs of the SCI-2 in a time domain. The PSSCH may be mapped to one or two layers (e.g., higher layers, physical layers, V2X layers). When the PSCCH is mapped to two layers, symbols of the SCI-2 may be repeated across both layers.

A vehicle (e.g., the UE115-a) in a V2X communication system may communicate SCI to other vehicles (e.g., the UE115-b) according to a DMRS pattern. In some examples, a DMRS pattern may span two, three, or four symbols. In other words, there may be two, three, or four-symbol DMRS patterns. A vehicle (e.g., the UE115-a) may signal the DMRS pattern in the SCI to other vehicles (e.g., the UE115-b). The other vehicles (e.g., the UE115-b) may use DMRSs of the DMRS pattern as a reference for channel estimation and demodulation of the PSSCH. In some examples, vehicles in a V2X communication system may support (re)transmission of sidelink data to increase the likelihood that the sidelink data is received successfully. HARQ feedback may be one technique for increasing the likelihood that the sidelink data is received correctly over the D2D communication link205. HARQ may include a combination of error detection (e.g., using a CRC), FEC, and (re)transmission (e.g., ARQ). In some examples, vehicles in a V2X communication system may provide HARQ feedback via a physical feedback channel. For example, the physical feedback channel may be a PSFCH. An example of a physical layer structure for direct communications, such as sidelink communications is described with reference toFIG. 4.

FIG. 4illustrates an example of a block diagram400that supports sidelink communications in accordance with one or more aspects of the present disclosure. The block diagram400may implement aspects of the wireless communications system100and200described with reference toFIGS. 1 and 2, respectively. For example, the block diagram400may be based on a configuration by a UE115, and implemented by the UE115. In the example illustrated inFIG. 4, the block diagram400may be applicable to implementations or instances when the UE115is configured with direct communication operations, such as sidelink communication operations in V2X and V2V communication systems. For example, the block diagram400may include a PSCCH405and a PSSCH410, which may correspond to time resources (for example, a symbol, a minislot, a slot, a subframe, a frame), as well as frequency resources (for example, subcarriers, carriers). In the example illustrated inFIG. 4, the PSCCH405may span a single subchannel415, while the PSSCH410may span multiple subchannels415. A subchannel415may occupy a number of PRBs.

Similarly, in the example illustrated inFIG. 4, a PSFCH420may correspond to time resources (for example, a symbol, a minislot, a slot, a subframe, a frame), as well as frequency resources (for example, subcarriers, carriers). In some examples, the PSFCH420may span one, two, or four symbols. For example, the PSFCH420may span two symbols. A slot with a PSFCH may have fewer symbols (e.g., three fewer symbols) for PSSCH than a slot without the PSFCH. In other words, a PSSCH may occupy less symbols of a slot when a PSFCH occupies at least one symbol of the slot. In some examples, a gap symbol425may, in some examples, separate the PSSCH410and the PSFCH420.

Returning toFIG. 2, in some examples, a vehicle (e.g., the UE115-a) in a V2X communication system may communicate channel state information (CSI) reports over the D2D communication link205. In some examples, the vehicle (e.g., the UE115-a) in the V2X communication system may trigger a CSI report in an SCI message. Another vehicle (e.g., the UE115-b) in the V2X communication system may transmit CSI reference signals (CSI-RS) exclusively when the transmitter vehicle (e.g., the UE115-a) triggers the CSI report via the SCI message. In some examples, the other vehicle (e.g., the UE115-b) may transmit the CSI-RS in a unicast sidelink transmission over the D2D communication link205. Time and frequency resources associated with the CSI-RS may correspond to a PSSCH bandwidth.

As demand for communication efficiency increases, some wireless communications systems, may fail to provide satisfactory direct communications, and as a result, may be unable to support high reliability or low latency direct communications, among other examples. Various aspects of the described techniques relate to configuring one or more of the UE115-aand the UE115-bto support high reliability or low latency direct communications in the wireless communications system200. The described techniques may be used to configure one or more of the UE115-aand the UE115-bto determine a TBS215of a transport block210(e.g., transport block210-a, transport block210-b) for direct communications, such as sidelink communications. In some examples, the TBS may include a number of bits for transmitting data over the D2D communication link205. For example, a vehicle (e.g., the UE115-a) in a V2X communication system may determine a TBS215to transmit (or receive) an SCI message over a PSCCH via the D2D communication link205to other vehicles (e.g., the UE115-b). A TBS215may be the same for an initial transmission and a re-transmission of a same transport block.

In some examples, various aspects of the described techniques relate to configuring one or more of the UE115-aand the UE115-bto determine a TBS215for sidelink communications when a DMRS pattern is dynamically-indicated. In some other examples, various aspects of the described techniques relate to configuring one or more of the UE115-aand the UE115-bto determine a TBS215for sidelink communications depending on a presence or an absence of a PSFCH. In other examples, various aspects of the described techniques relate to configuring one or more of the UE115-aand the UE115-bto determine a TBS215for sidelink communications depending on a second stage control (SCI-2) (e.g., based on a modulation and coding scheme (MCS) and a scaling factor). In some other examples, various aspects of the described techniques relate to configuring one or more of the UE115-aand the UE115-bto determine a TBS for sidelink communications depending on CSI-RS.

In some cases, to determine a TBS, the UE115-amay determine an estimate number of REs N′REwithin a PRB. For example, the UE115-amay determine an estimate number of REs N′REwithin a PRB according to Equation (1).

NSCRBis a number of subcarriers within the PRB, Nsymbshis a number of allocated symbols for a physical channel (e.g., a physical shared data channel (PSDCH)), NDMRSPRBis a number of REs for DMRS per PRB, and NohPRBan overhead associated with the PRB. In some examples, the NohPRBmay configurable to zero REs, 6 REs, 12 REs, or 18 REs. In some cases, to determine a TBS, the UE115-amay determine a number of REs NREwithin a slot according to Equation (2).

The UE115-amay determine a number of allocated PRBs (nPRB) (e.g., a total number of PRBs allocated to the UE for sidelink communications where the PRBs are allocated by a another device in the wireless communications system) for the UE115-a, and the UE115-amay use the determined value for NEfrom Equation (1) to determine the number of REs NREwithin a slot. As a result, the UE115-amay use the determined number of REs NREto determine the TBS.

In some examples, the UE115-amay identify SCI for sidelink communications, as described herein. For example, the UE115-amay identify SCI for sidelink communications with the UE115-b. Prior to transmitting (or receiving) the SCI on a physical sidelink channel, the UE115-amay determine a TBS for the SCI. The UE115-amay determine an estimate number of REs (N′RE) associated with a PRB for the sidelink communications. In some examples, the UE115-amay determine an estimate number of REs (N′RE) associated with the PRB for the sidelink communications, for example, according to Equation (1). The UE115-amay also determine a number of allocated PRBs (nPRB) for the sidelink communications, and determine a number of REs (NRE) associated with the PRB (e.g., a number of REs within the slot) for the sidelink communications based on the number of allocated PRBs (nPRB), for example, according to Equation (2).

According to various aspects of the described techniques, the UE115-amay determine a number of REs for a first SCI (e.g., first stage SCI-1 overhead), and subtract the number of REs for the first SCI from the estimate number of REs (N′RE) associated with the PRB or the number of REs (NRE) associated with the PRB, or both. In some examples, the UE115-amay determine control overhead associated with the first SCI, and refrain from using the control overhead in the estimate number of REs (N′RE) associated with the PRB or the number of REs (NRE) associated with the PRB, or both. As such, first stage control overhead may not be considered for TBS calculation.

In some examples, the UE115-amay determine that a first physical sidelink channel (e.g., a PSCCH) and a second physical sidelink channel (e.g., a PSSCH) are frequency division multiplexed. The UE115-amay determine that PSSCH occupies the number of REs associated with the PRB, and adjust an overhead of the PSCCH based on a value of the REs occupied by the PSSCH. In other words, a PSCCH overhead per PRB may be scaled by a fraction of REs in a symbol occupied by the PSCCH. The PSCCH overhead may be considered per slot.

In some other examples, the UE115-amay determine that a first physical sidelink channel (e.g., a PSCCH) and a second physical sidelink channel (e.g., a PSSCH) are time division multiplexed. The UE115-amay determine an overhead of the PSCCH per PRB based on that the first sidelink channel and the second physical sidelink channel being time division multiplexed. Thus, the PSCCH overhead may be considered per PRB. Alternatively, the PSCCH overhead may be considered per slot. The UE115-amay determine a number of symbols associated with the PSCCH (NPSCCHsymb) or the PSSCH, or both, and determine a number of symbols exclusively including the PSCCH. The UE115-amay exclude the number of symbols exclusively including the PSCCH from the estimate number of REs (NE) associated with the PRB or the number of REs (NRE) associated with the PRB, or both. In other words, the number of PSSCH symbols excludes those containing PSCCH only. For example, the UE115-amay determine an estimate number of REs (NE) associated with the PRB according to Equation (3).

According to various aspects of the described techniques, the UE115-amay determine a number of REs for a second SCI (e.g., second stage SCI-2 overhead), and subtract the number of REs for the second SCI from the estimate number of REs (N′RE) associated with the PRB or the number of REs (NRE) associated with the PRB, or both. The UE115-amay determine a control overhead associated with the second SCI based on a target code rate associated with an MCS. Thus, SCI-2 overhead may be calculated using the target code rate from the MCS (instead of actual TBS). The UE115-amay ignore the control overhead associated with the second SCI. In other words, the overhead associated with the second SCI (e.g., SCI-2 overhead) is not considered for TBS calculations. In some examples, the UE115-amay identify an MCS for the second SCI, and identify a target code rate based on the MCS for the second SCI. The UE115-amay determine a number of REs for the second stage control (e.g., SCI-2) using the target code rate from the MCS (instead of actual TBS).

In some examples, according to various aspects of the described techniques, the UE115-amay receive signaling including an indication of an overhead value (Z), which the UE115-amay use to determine TBS for sidelink communications. In some examples, the overhead value (Z) may be an overall overhead value, and the UE115-amay determine an estimate number of REs (N′RE) associated with the PRB according to Equation (4).

Alternatively, the overhead value (Z) may be an offset overhead value relative to a DMRS pattern. In some examples, the overhead value (Z) may be an overall overhead value, and the UE115-amay determine an estimate number of REs (N′RE) associated with the PRB according to Equation (5).

According to various aspects of the described techniques, the UE115-amay receive signaling including an indication of a number of symbols (Y) to use for the TBS determination. In some examples, the number of symbols (Y) may be an offset to the number of symbols relative to the number of symbols available for PSSCH. The UE115-amay, for example, determine an estimate number of REs (NE) associated with the PRB according to Equation (6).

Alternatively, the number of symbols (Y) may be a total number of symbols to use for TBS determination. The UE115-amay thus determine an estimate number of REs (N′RE) associated with the PRB according to Equation (7).

In some examples, one or more of the overhead value (Z) and the number of symbols (Y) may be signaled using a single field in a message (e.g., jointly encoded or index into a set of values).

According to various aspects of the described techniques, the UE115-amay determine an overhead of a PSFCH based on a period of the PSFCH. The UE115-amay scale the overhead of the PSFCH based on the period of the PSFCH. As such, an overhead of the PSFCH may be scaled by a value dependent on the PSFCH period. Alternatively, the UE115-amay determine an average of the overhead of the PSFCH over the period of the PSFCH. Thus, an overhead of the PSFCH may be taken as an average over a PSFCH period. The UE115-amay apply the overhead of the PSFCH as a value per PRB. Alternatively, the UE115-amay apply the overhead of the PSFCH as a change in a number of available PSSCH symbols.

In some examples, according to various aspects of the described techniques, the UE115-amay adjust the number of REs (NRE) associated with the PRB for the sidelink communications to a number of REs associated with the PRB for non-sidelink communications (Uu). For example, the UE115-amay round the number of REs (NRE) associated with the PRB for the sidelink communications to a nearest number of REs associated with the PRB for non-sidelink communications (Uu). Alternatively, the UE115-amay round the number of REs (NRE) associated with the PRB for the sidelink communications to a floor value or a ceiling value associated with a number of REs associated with the PRB for non-sidelink communications (Uu).

In some examples, according to various aspects of the described techniques, the UE115-amay also determine a CSI-RS overhead and refrain from using the CSI-RS overhead from determining the estimate number of REs (N′RE) associated with the PRB or determining the number of REs (NRE) associated with the PRB, or both. In other words, CSI-RS overhead is not accounted for in TBS determination for sidelink communications. Upon determining a TBS for the SCI based on one or more of the above various aspects, the UE115-amay transmit (or receive) the SCI on the physical sidelink channel (e.g., PSCCH, PSSCH) to the UE115-b.

The operations performed by the UEs115, for example, may provide improvements to direction communication operations related to sidelink communication in the wireless communications system200. Further, the operations performed by the UEs115may provide benefits and enhancements to the operation of the UEs115. For example, by supporting TBS determination operations for sidelink communications, the UEs115may preserve power, while simultaneously supporting higher reliability and lower latency sidelink communications, resulting in enhanced power efficiency and network throughput in the wireless communications system200.

FIG. 5shows a block diagram500of a device505that supports sidelink communications in accordance with one or more aspects of the present disclosure. The device505may be an example of aspects of a device as described herein. The device505may include a receiver510, a UE communications manager515, and a transmitter520. The device505may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

The receiver510may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to TBS determination for sidelink communications, etc.). Information may be passed on to other components of the device505. The receiver510may be an example of aspects of the transceiver820described with reference toFIG. 8. The receiver510may utilize a single antenna or a set of antennas.

The UE communications manager515may identify sidelink information for sidelink communications, determine a TBS for the sidelink information based on an overhead of a second physical sidelink channel for communicating the sidelink information, encode the sidelink information for the sidelink communications based on the TBS, and transmit the encoded sidelink information on a physical sidelink channel. The UE communications manager515may also identify sidelink information for sidelink communications, determine a TB S for the sidelink information based on an overhead of a second physical sidelink channel for communicating the sidelink information, decode the sidelink information for the sidelink communications based on the TBS, and receive the decoded sidelink information on a physical sidelink channel. The UE communications manager515may be an example of aspects of the UE communications manager810described herein.

The UE communications manager515may as described herein be implemented to realize one or more potential advantages. One implementation may allow the device505to save power and increase battery life by communicating with a base station105(as shown inFIG. 1) more efficiently. For example, the device505may reduce a number of retransmissions associated with sidelink communications when resources for TBS determination change in a wireless communications system, such as a V2X system. In addition, the device505may experience reduced complexity, better throughput through efficient TBS determination for sidelink communications. Another implementation may promote higher reliability and lower latency communications at the device505due to TBS determination flexibility of the device505, as a result of supporting TBS determination for sidelink communications.

The UE communications manager515may be an example of means for performing various aspects of TBS determination for sidelink communications as described herein. The UE communications manager515, or its sub-components, may be implemented in hardware (e.g., in communications management circuitry). The circuitry may comprise of processor, digital signal processor (DSP), an application-specific integrated circuit (ASIC), an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure.

In another implementation, the UE communications manager515, or its sub-components, may be implemented in code (e.g., as communications management software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the UE communications manager515, or its sub-components may be executed by a general-purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device.

In some examples, the UE communications manager515may be configured to perform various operations (e.g., receiving, determining, transmitting, subtracting, ignoring, identifying, scaling, excluding, adjusting, refraining from, applying, allocating) using or otherwise in cooperation with the receiver510, the transmitter520, or both.

FIG. 6shows a block diagram600of a device605that supports sidelink communications in accordance with one or more aspects of the present disclosure. The device605may be an example of aspects of a device505or a UE115as described herein. The device605may include a receiver610, a UE communications manager615, and a transmitter645. The device605may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

The UE communications manager615may be an example of aspects of the UE communications manager515as described herein. The UE communications manager615may include a control component620, a transport block component625, a sidelink component630, a resource component635, and a signaling component640. The UE communications manager615may be an example of aspects of the UE communications manager810described herein.

The control component620may identify sidelink information for sidelink communications. The transport block component625may determine a TBS for the sidelink information based on an overhead of a second physical sidelink channel for communicating the sidelink information. The control component620may encode the sidelink information for the sidelink communications based on the TBS. The sidelink component630may transmit the encoded sidelink information on a physical sidelink channel. The resource component635may allocate resources for sidelink communications on a physical sidelink channel. The signaling component640may transmit, based on the allocating, signaling including an indication of the resources for the sidelink communications. The sidelink component630may receive SCI on the physical sidelink channel based on the signaling, where TBS for the SCI is determined based on the indication of the resources for the sidelink communications. The control component620may identify sidelink information for sidelink communications. The transport block component625may determine a TBS for the sidelink information based on an overhead of a second physical sidelink channel for communicating the sidelink information. The control component620may decode the sidelink information for the sidelink communications based on the TBS. The sidelink component630may receive the decoded sidelink information on a physical sidelink channel.

The transmitter645may transmit signals generated by other components of the device605. In some examples, the transmitter645may be collocated with a receiver610in a transceiver component. For example, the transmitter645may be an example of aspects of the transceiver820described with reference toFIG. 8. The transmitter645may utilize a single antenna or a set of antennas.

FIG. 7shows a block diagram700of a UE communications manager705that supports sidelink communications in accordance with one or more aspects of the present disclosure. The UE communications manager705may be an example of aspects of a UE communications manager515, a UE communications manager615, or a UE communications manager810described herein. The UE communications manager705may include a control component710, a transport block component715, a sidelink component720, a multiplexing component725, a scale component730, a resource component735, and a signaling component740. Each of these components may communicate, directly or indirectly, with one another (e.g., via one or more buses).

The control component710may identify sidelink information for sidelink communications. The control component710may encode (or decode) the sidelink information for the sidelink communications based on a TBS. In some examples, the control component710may determine control overhead associated with a first SCI. In some examples, the control component710may refrain from using the control overhead in an estimate number of REs associated with a PRB or a number of REs associated with the allocated PRBs, or both, where determining the TBS may be based on the refraining. In some examples, the control component710may determine an overhead of the PSCCH per PRB based on determining that a first physical sidelink channel and a second physical sidelink channel are time division multiplexed, where determining the TBS may be based on the overhead of the PSCCH being per PRB.

In some examples, the control component710may determine a control overhead associated with a second SCI based on a target code rate associated with an MCS, where determining the TBS may be based on the control overhead associated with the second SCI. In some examples, the control component710may ignore the control overhead associated with the second SCI, where determining the TBS may be based on ignoring the control overhead associated with the second SCI. In some examples, the control component710may identify an MCS for the sidelink communications. In some examples, the control component710may identify a target code rate based on the MCS for the sidelink communications, where determining the number of REs for the second SCI may be based on the target code rate.

In some examples, the control component710may determine a CSI-RS overhead. In some examples, the control component710may refrain from using the CSI-RS overhead for determining the estimate number of REs associated with the PRB or determining the number of REs associated with the allocated PRBs, or both, where determining the TBS may be based on the ignoring. In some examples, the control component710may determine a number of subcarriers associated with the PRB, where determining the estimate number of REs associated with the PRB may be based on the number of subcarriers associated with the PRB. In some examples, the control component710may determine a number of allocated symbols associated with a physical sidelink channel, where determining the estimate number of REs associated with the PRB may be based on one or more of the number of subcarriers associated with the PRB and the number of allocated symbols associated with the physical sidelink channel.

In some examples, the control component710may determine a DMRS overhead associated with the PRB, where determining the estimate number of REs associated with the PRB may be based on the DMRS signal overhead associated with the PRB. In some examples, the control component710may determine control overhead associated with the PRB, where determining the estimate number of REs associated with the PRB may be based on the control overhead associated with the PRB. In some examples, the control component710may determine an overhead of the physical sidelink channel based on a period of the physical sidelink channel, where determining the TBS is based on the overhead of the physical sidelink channel.

In some examples, the control component710may scale the overhead of the physical sidelink channel based on the period of the physical sidelink channel, where determining the TBS is based on the scaling. In some examples, the control component710may determine an average of the overhead of the physical sidelink channel over the period of the physical sidelink channel, where determining the TBS is based on the average of the overhead of the physical sidelink channel over the period of the physical sidelink channel. In some examples, the control component710may apply the overhead of the physical sidelink channel as a value per PRB, where determining the TBS is based on the applying. In some cases, the physical sidelink channel includes a PSFCH. In some cases, the overhead of the physical sidelink channel corresponds to a number of available symbols of a second physical sidelink channel, the second physical sidelink channel including a PSSCH.

The transport block component715may determine the TB S for the sidelink information based on an overhead of a second physical sidelink channel for communicating the sidelink information. In some examples, the transport block component715may determine an estimate number of REs associated with a PRB for the sidelink communications, where determining the TBS is based on the estimate number of REs associated with the PRB. In some examples, the transport block component715may determine a number of allocated PRBs for the sidelink communications. In some examples, the transport block component715may determine a number of REs associated with the allocated PRBs for the sidelink communications based on the number of allocated PRBs or the estimate number of REs associated with the PRB, or both, where determining the TBS is based on the number of REs associated with the allocated PRBs for the sidelink communications.

In some examples, the transport block component715may determine a number of REs for a first SCI. In some examples, the transport block component715may subtract the number of REs for the first SCI from the number of REs associated with the PRB, where determining the TBS may be based on the subtracting. In some examples, the transport block component715may determine the TBS is based on the overhead of the PSCCH per slot. In some examples, the transport block component715may determine the TBS is based on an overhead of the PSCCH per slot. In some examples, the transport block component715may adjust the number of REs associated with the allocated PRBs for the sidelink communications to a number of REs associated with the allocated PRBs for non-sidelink communications.

The sidelink component720may transmit (or receive) the encoded (or decoded) sidelink information on the physical sidelink channel. In some examples, the sidelink component720may receive sidelink information on the physical sidelink channel based on the signaling, where the TBS for the sidelink information is determined based on the indication of the resources for the sidelink communications. In some examples, the sidelink component720may transmit (or receive) the first SCI on a PSCCH based on the TBS. In some examples, the sidelink component720may transmit (or receive) the second SCI on a PSSCH based on the TBS. In some cases, the physical sidelink channel includes a PSSCH. In some cases, the physical sidelink channel includes a PSCCH.

The resource component735may allocate resources for sidelink communications on a physical sidelink channel. In some examples, the resource component735may determine a number of symbols associated with the PSCCH or the PSSCH, or both. In some examples, the resource component735may determine a number of symbols exclusively including the PSCCH. In some examples, the resource component735may exclude the number of symbols exclusively including the PSCCH from the estimate number of REs associated with the PRB or the number of REs associated with the allocated PRBs, or both, where determining the TBS is based on the excluding.

In some examples, the resource component735may determine a number of REs for a second SCI. In some examples, the resource component735may subtract the number of REs for the second SCI from the estimate number of REs associated with the PRB or the number of REs associated with the allocated PRBs, or both, where determining the TBS is based on the subtracting.

The signaling component740may transmit, based on the allocating, signaling including an indication of the resources for the sidelink communications. In some examples, the signaling component740may receive signaling including an indication of an overhead value, where determining the estimate number of REs associated with the PRB is based on the signaled overhead value. In some examples, the signaling component740may receive signaling including an indication of an offset overhead value relative to a demodulation reference signal pattern, where determining the estimate number of REs associated with the PRB is based on the signaled offset overhead value. In some examples, the signaling component740may receive signaling including an indication of a number of symbols to use for the TBS determination, where determining the TBS is based on the signaling.

In some examples, the signaling component740may determine a number of allocated symbols associated with the physical sidelink channel, the physical sidelink channel including a PSCCH. In some examples, the signaling component740may subtract the number of symbols to use for the TBS determination from the number of allocated symbols associated with the physical sidelink channel, where determining the estimate number of REs associated with the PRB is based on the subtracting. In some examples, the signaling component740may determine the estimate number of REs associated with the PRB is based on the number of symbols to use for the TBS determination.

In some examples, the signaling component740may transmit signaling including an indication of an overhead value, where an estimate number of REs associated with a PRB for the sidelink communications is based on the signaled overhead value. In some examples, the signaling component740may transmit signaling including an indication of a number of symbols to use for the TBS determination, where the TBS is based on the number of symbols to use for the TBS determination.

The multiplexing component725may determine that a first physical sidelink channel and a second physical sidelink channel are frequency division multiplexed, the first physical sidelink channel includes a PSSCH and the second physical sidelink channel includes a PSCCH, where determining the TBS is based on that the first physical sidelink channel and the second physical sidelink channel are frequency division multiplexed. In some examples, determining that a first physical sidelink channel and a second physical sidelink channel are time division multiplexed, the first physical sidelink channel includes a PSSCH and the second physical sidelink channel includes a PSCCH, where determining the TBS is based on determining that the first physical sidelink channel and the second physical sidelink channel are time division multiplexed. The scale component730may determine that the PSSCH occupies the number of REs associated with the allocated PRBs. In some examples, the scale component730may adjust an overhead of the PSCCH based at least in part on a value of the number of REs occupied by the PSSCH, where the overhead of the PSCCH is per slot.

The UE communications manager810may identify sidelink information for sidelink communications, determine a TBS for the sidelink information based on an overhead of a second physical sidelink channel for communicating the sidelink information, encode the sidelink information for the sidelink communications based on the TBS, and transmit the encoded sidelink information on the physical sidelink channel. The UE communications manager810may identify sidelink information for sidelink communications, determine a TBS for the sidelink information based on an overhead of a second physical sidelink channel for communicating the sidelink information, decode the sidelink information for the sidelink communications based on the TBS, and receive the decoded sidelink information on the physical sidelink channel.

The memory830may include random-access memory (RAM) and read-only memory (ROM). The memory830may store computer-readable, computer-executable code835including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory830may contain, among other things, a basic I/O system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices.

The base station communications manager915may allocate resources for sidelink communications on a physical sidelink channel, transmit, based on the allocating, signaling including an indication of the resources for the sidelink communications, and receive SCI on the physical sidelink channel based on the signaling, where TBS for the SCI is determined based on the indication of the resources for the sidelink communications. The base station communications manager915may be an example of aspects of the base station communications manager1210described herein.

The base station communications manager915may be an example of means for performing various aspects of TBS determination for sidelink communications. The base station communications manager915, or its sub-components, may be implemented in hardware (e.g., in communications management circuitry). The circuitry may comprise of processor, DSP, an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure.

In another implementation, the base station communications manager915, or its sub-components, may be implemented in code (e.g., as communications management software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the base station communications manager915, or its sub-components may be executed by a general-purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device.

In some examples, the base station communications manager915may be configured to perform various operations (e.g., receiving, determining, transmitting, allocating, etc.) using or otherwise in cooperation with the receiver910, the transmitter920, or both.

FIG. 10shows a block diagram1000of a device1005that supports transport sidelink communications in accordance with one or more aspects of the present disclosure. The device1005may be an example of aspects of a device905, or a base station105as described herein. The device1005may include a receiver1010, a base station communications manager1015, and a transmitter1035. The device1005may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

The base station communications manager1015may be an example of aspects of the base station communications manager915as described herein. The base station communications manager1015may include a resource component1020, a signaling component1025, and a sidelink component1030. The base station communications manager1015may be an example of aspects of the base station communications manager915described herein.

The resource component1020may allocate resources for sidelink communications on a physical sidelink channel. The signaling component1025may transmit, based on the allocating, signaling including an indication of the resources for the sidelink communications. The sidelink component1030may receive SCI on the physical sidelink channel based on the signaling, where TBS for the SCI is determined based on the indication of the resources for the sidelink communications.

The transmitter1035may transmit signals generated by other components of the device1005. In some examples, the transmitter1035may be collocated with a receiver1010in a transceiver module. For example, the transmitter1035may be an example of aspects of the transceiver1220described with reference toFIG. 12. The transmitter1035may utilize a single antenna or a set of antennas.

FIG. 11shows a block diagram1100of a base station communications manager1105that supports sidelink communications in accordance with one or more aspects of the present disclosure. The base station communications manager1105may be an example of aspects of a base station communications manager915, a base station communications manager1015, or a base station communications manager1210described herein. The base station communications manager1105may include a resource component1110, a signaling component1115, and a sidelink component1120. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses).

The resource component1110may allocate resources for sidelink communications on a physical sidelink channel. The signaling component1115may transmit, based on the allocating, signaling including an indication of the resources for the sidelink communications. In some examples, the signaling component1115may transmit signaling including an indication of an overhead value, where an estimate number of REs associated with a PRB for the sidelink communications is based on the signaled overhead value. In some examples, the signaling component1115may transmit signaling including an indication of a number of symbols to use for the TBS determination, where the TBS is based on the number of symbols to use for the TBS determination. The sidelink component1120may receive SCI on the physical sidelink channel based on the signaling, where TBS for the SCI is determined based on the indication of the resources for the sidelink communications. In some cases, the physical sidelink channel includes a PSSCH. In some cases, the physical sidelink channel includes a PSCCH.

FIG. 12shows a diagram of a system1200including a device1205that supports sidelink communications in accordance with one or more aspects of the present disclosure. The device1205may be an example of or include the components of device905, device1005, or a base station105as described herein. The device1205may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a base station communications manager1210, a network communications manager1215, a transceiver1220, an antenna1225, memory1230, a processor1240, and an inter-station communications manager1245. These components may be in electronic communication via one or more buses (e.g., bus1250).

The base station communications manager1210may allocate resources for sidelink communications on a physical sidelink channel, transmit, based on the allocating, signaling including an indication of the resources for the sidelink communications, and receive SCI on the physical sidelink channel based on the signaling, where TBS for the SCI is determined based on the indication of the resources for the sidelink communications.

The transceiver1220may communicate bi-directionally, via one or more antennas, wired, or wireless links as described herein. For example, the transceiver1220may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver1220may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas. In some cases, the device1205may include a single antenna1225. However, in some cases, the device may have more than one antenna1225, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

The memory1230may include RAM, ROM, or a combination thereof. The memory1230may store computer-readable code1235including instructions that, when executed by a processor (e.g., the processor1240) cause the device to perform various functions described herein. In some cases, the memory1230may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices.

FIG. 13shows a flowchart illustrating a method1300that supports sidelink communications in accordance with one or more aspects of the present disclosure. The operations of method1300may be implemented by a device or its components as described herein. For example, the operations of method1300may be performed by a UE communications manager as described with reference toFIGS. 5 through 8. In some examples, a device may execute a set of instructions to control the functional elements of the device to perform the functions described herein. Additionally or alternatively, a device may perform aspects of the functions described herein using special-purpose hardware.

At1305, the device may identify sidelink information for sidelink communications. The operations of1305may be performed according to the methods described herein. In some examples, aspects of the operations of1305may be performed by a control component as described with reference toFIGS. 5 through 8.

At1310, the device may determine a TBS for the sidelink information based on an overhead of a second physical sidelink channel for communicating the sidelink information. The operations of1310may be performed according to the methods described herein. In some examples, aspects of the operations of1310may be performed by a transport block component as described with reference toFIGS. 5 through 8.

At1315, the device may encode the sidelink information for the sidelink communications based on the TBS. The operations of1315may be performed according to the methods described herein. In some examples, aspects of the operations of1315may be performed by a control component as described with reference toFIGS. 5 through 8.

At1320, the device may transmit the encoded sidelink information on a physical sidelink channel. The operations of1320may be performed according to the methods described herein. In some examples, aspects of the operations of1320may be performed by a sidelink component as described with reference toFIGS. 5 through 8.

FIG. 14shows a flowchart illustrating a method1400that supports sidelink communications in accordance with one or more aspects of the present disclosure. The operations of method1400may be implemented by a device or its components as described herein. For example, the operations of method1400may be performed by a UE communications manager as described with reference toFIGS. 5 through 8. In some examples, a device may execute a set of instructions to control the functional elements of the device to perform the functions described herein. Additionally or alternatively, a device may perform aspects of the functions described herein using special-purpose hardware.

At1405, the device may identify sidelink information for sidelink communications. The operations of1405may be performed according to the methods described herein. In some examples, aspects of the operations of1405may be performed by a control component as described with reference toFIGS. 5 through 8.

At1410, the device may determine an estimate number of REs associated with a PRB for the sidelink communications. The operations of1410may be performed according to the methods described herein. In some examples, aspects of the operations of1410may be performed by a transport block component as described with reference toFIGS. 5 through 8.

At1415, the device may determine a TBS for the SCI based on the estimate number of REs associated with the PRB. The operations of1415may be performed according to the methods described herein. In some examples, aspects of the operations of1415may be performed by a transport block component as described with reference toFIGS. 5 through 8.

At1420, the device may encode the sidelink information for the sidelink communications based on the TBS. The operations of1420may be performed according to the methods described herein. In some examples, aspects of the operations of1420may be performed by a control component as described with reference toFIGS. 5 through 8.

At1425, the device may transmit the encoded sidelink information on a physical sidelink channel. The operations of1425may be performed according to the methods described herein. In some examples, aspects of the operations of1425may be performed by a sidelink component as described with reference toFIGS. 5 through 8.

FIG. 15shows a flowchart illustrating a method1500that supports sidelink communications in accordance with one or more aspects of the present disclosure. The operations of method1500may be implemented by a device or its components as described herein. For example, the operations of method1500may be performed by a UE communications manager as described with reference toFIGS. 5 through 8. In some examples, a device may execute a set of instructions to control the functional elements of the device to perform the functions described herein. Additionally or alternatively, a device may perform aspects of the functions described herein using special-purpose hardware.

At1505, the device may identify sidelink information for sidelink communications. The operations of1505may be performed according to the methods described herein. In some examples, aspects of the operations of1505may be performed by a control component as described with reference toFIGS. 5 through 8.

At1510, the device may determine a number of allocated PRBs for the sidelink communications. The operations of1510may be performed according to the methods described herein. In some examples, aspects of the operations of1510may be performed by a transport block component as described with reference toFIGS. 5 through 8.

At1515, the device may determine a number of REs associated with the allocated PRBs for the sidelink communications based on the number of allocated PRBs or an estimate number of REs associated with the PRB, or both. The operations of1515may be performed according to the methods described herein. In some examples, aspects of the operations of1515may be performed by a transport block component as described with reference toFIGS. 5 through 8.

At1520, the device may determine a TBS based on the number of REs associated with the allocated PRBs for the sidelink communications. The operations of1520may be performed according to the methods described herein. In some examples, aspects of the operations of1520may be performed by a transport block component as described with reference toFIGS. 5 through 8.

At1525, the device may encode the sidelink information for the sidelink communications based on the TBS. The operations of1525may be performed according to the methods described herein. In some examples, aspects of the operations of1525may be performed by a control component as described with reference toFIGS. 5 through 8.

At1530, the device may transmit the encoded sidelink information on a physical sidelink channel. The operations of1530may be performed according to the methods described herein. In some examples, aspects of the operations of1530may be performed by a sidelink component as described with reference toFIGS. 5 through 8.

FIG. 16shows a flowchart illustrating a method1600that supports sidelink communications in accordance with one or more aspects of the present disclosure. The operations of method1600may be implemented by a device or its components as described herein. For example, the operations of method1600may be performed by a UE communications manager as described with reference toFIGS. 5 through 8. In some examples, a device may execute a set of instructions to control the functional elements of the device to perform the functions described herein. Additionally or alternatively, a device may perform aspects of the functions described herein using special-purpose hardware.

At1605, the device may identify sidelink information for sidelink communications. The operations of1605may be performed according to the methods described herein. In some examples, aspects of the operations of1605may be performed by a control component as described with reference toFIGS. 5 through 8.

At1610, the device may determine a number of REs for a first SCI. The operations of1615may be performed according to the methods described herein. In some examples, aspects of the operations of1615may be performed by a transport block component as described with reference toFIGS. 5 through 8.

At1615, the device may subtract the number of REs for the first SCI from a number of REs associated with allocated PRBs. The operations of1620may be performed according to the methods described herein. In some examples, aspects of the operations of1620may be performed by a transport block component as described with reference toFIGS. 5 through 8.

At1620, the device may determine a TBS based on the subtracting. The operations of1625may be performed according to the methods described herein. In some examples, aspects of the operations of1625may be performed by a transport block component as described with reference toFIGS. 5 through 8.

At1625, the device may transmit the first SCI on a PSCCH based on the TBS. The operations of1630may be performed according to the methods described herein. In some examples, aspects of the operations of1630may be performed by a sidelink component as described with reference toFIGS. 5 through 8.

FIG. 17shows a flowchart illustrating a method1700that supports sidelink communications in accordance with one or more aspects of the present disclosure. The operations of method1700may be implemented by a device or its components as described herein. For example, the operations of method1700may be performed by a UE communications manager as described with reference toFIGS. 5 through 8. In some examples, a device may execute a set of instructions to control the functional elements of the device to perform the functions described herein. Additionally or alternatively, a device may perform aspects of the functions described herein using special-purpose hardware.

At1705, the device may identify sidelink information for sidelink communications. The operations of1705may be performed according to the methods described herein. In some examples, aspects of the operations of1705may be performed by a control component as described with reference toFIGS. 5 through 8.

At1710, the device may determine a number of REs for a second SCI. The operations of1710may be performed according to the methods described herein. In some examples, aspects of the operations of1710may be performed by a transport block component as described with reference toFIGS. 5 through 8.

At1715, the device may subtract the number of REs for the second SCI from an estimate number of REs associated with the PRB or a number of REs associated with allocated PRBs, or both. The operations of1715may be performed according to the methods described herein. In some examples, aspects of the operations of1715may be performed by a transport block component as described with reference toFIGS. 5 through 8.

At1720, the device may determine a TBS based on the subtracting. The operations of1720may be performed according to the methods described herein. In some examples, aspects of the operations of1720may be performed by a transport block component as described with reference toFIGS. 5 through 8.

At1725, the device may transmit the second SCI on a PSCCH based on the TBS. The operations of1725may be performed according to the methods described herein. In some examples, aspects of the operations of1725may be performed by a sidelink component as described with reference toFIGS. 5 through 8.

FIG. 18shows a flowchart illustrating a method1800that supports sidelink communications in accordance with one or more aspects of the present disclosure. The operations of method1800may be implemented by a device or its components as described herein. For example, the operations of method1800may be performed by a UE communications manager as described with reference toFIGS. 5 through 8. In some examples, a device may execute a set of instructions to control the functional elements of the device to perform the functions described herein. Additionally or alternatively, a device may perform aspects of the functions described herein using special-purpose hardware.

At1805, the device may identify sidelink information for sidelink communications. The operations of1805may be performed according to the methods described herein. In some examples, aspects of the operations of1805may be performed by a control component as described with reference toFIGS. 5 through 8.

At1810, the device may determine a TBS for the sidelink information based on an overhead of a second physical sidelink channel for communicating the sidelink information. The operations of1810may be performed according to the methods described herein. In some examples, aspects of the operations of1810may be performed by a transport block component as described with reference toFIGS. 5 through 8.

At1815, the device may decode the sidelink information for the sidelink communications based on the TBS. The operations of1815may be performed according to the methods described herein. In some examples, aspects of the operations of1815may be performed by a control component as described with reference toFIGS. 5 through 8.

At1820, the device may receive the decoded sidelink information on a physical sidelink channel. The operations of1820may be performed according to the methods described herein. In some examples, aspects of the operations of1820may be performed by a sidelink component as described with reference toFIGS. 5 through 8.

FIG. 19shows a flowchart illustrating a method1900that supports sidelink communications in accordance with one or more aspects of the present disclosure. The operations of method1900may be implemented by a device (e.g., a base station) or its components as described herein. For example, the operations of method1900may be performed by a base station communications manager as described with reference toFIGS. 9 through 12. In some examples, a device may execute a set of instructions to control the functional elements of the device to perform the functions described herein. Additionally or alternatively, a device may perform aspects of the functions described herein using special-purpose hardware.

At1905, the device may allocate resources for sidelink communications on a physical sidelink channel. The operations of1905may be performed according to the methods described herein. In some examples, aspects of the operations of1905may be performed by a resource component as described with reference toFIGS. 9 through 12.

At1910, the device may transmit, based on the allocating, signaling including an indication of the resources for the sidelink communications. The operations of1910may be performed according to the methods described herein. In some examples, aspects of the operations of1910may be performed by a signaling component as described with reference toFIGS. 9 through 12.

At1915, the device may receive SCI on the physical sidelink channel based on the signaling, where TBS for the SCI is determined based on the indication of the resources for the sidelink communications. The operations of1915may be performed according to the methods described herein. In some examples, aspects of the operations of1915may be performed by a sidelink component as described with reference toFIGS. 9 through 12.

Aspect 1: A method for wireless communication, comprising: encoding sidelink information for sidelink communications based on a TBS, and transmitting the encoded sidelink information on a physical sidelink channel, the transport block size based at least in part on an overhead of a second physical sidelink channel for communicating the sidelink information.

Aspect 2: The method of aspect 1, further comprising: determining an estimate number of resource elements associated with a physical resource block for sidelink communications, wherein the transport block size is based at least in part on the estimate number of resource elements associated with the physical resource block.

Aspect 3: The method of aspect 2, further comprising: determining a number of allocated physical resource blocks for the sidelink communications; and determining a number of resource elements associated with the allocated physical resource blocks for the sidelink communications based at least in part on the number of allocated physical resource blocks or the estimate number of resource elements associated with the physical resource block, or both, wherein the transport block size is based at least in part on the number of resource elements associated with the allocated physical resource blocks for the sidelink communications.

Aspect 4: The method of aspect 3, further comprising: transmitting signaling comprising an indication of a number of symbols to use for the transport block size determination, wherein the transport block size is based at least in part on the signaling.

Aspect 5: The method of aspect 4, further comprising: determining a number of allocated symbols associated with the physical sidelink channel, the physical sidelink channel comprising a physical sidelink control channel; and subtracting the number of symbols to use for the transport block size determination from the number of allocated symbols associated with the physical sidelink channel, wherein determining the estimate number of resource elements associated with the physical resource block is based at least in part on the subtracting.

Aspect 6: The method of any of aspects 4 through 5, wherein determining the estimate number of resource elements associated with the physical resource block is based at least in part on the number of symbols to use for the transport block size determination.

Aspect 7: The method of any of aspects 3 through 6, further comprising: determining a number of resource elements for a first sidelink control information; and subtracting the number of resource elements for the first sidelink control information from the number of resource elements associated with the allocated physical resource blocks, wherein the transport block size is based at least in part on the subtracting.

Aspect 8: The method of aspect 7, wherein transmitting the sidelink information on the physical sidelink channel comprises: transmitting the first sidelink control information on a physical sidelink control channel based at least in part on the transport block size.

Aspect 9: The method of any of aspects 7 through 8, further comprising: determining that a first physical sidelink channel and the second physical sidelink channel are frequency division multiplexed, the first physical sidelink channel comprises a physical sidelink shared channel and the second physical sidelink channel comprises a physical sidelink control channel, wherein the transport block size is based at least in part on that the first physical sidelink channel and the second physical sidelink channel are frequency division multiplexed.

Aspect 10: The method of aspect 9, further comprising: determining that the physical sidelink shared channel occupies the number of resource elements associated with the allocated physical resource blocks; and adjusting an overhead of the physical sidelink control channel based at least in part on a value of the number of resource elements occupied by the physical sidelink shared channel, wherein the overhead of the physical sidelink control channel is per slot.

Aspect 11: The method of any of aspects 7 through 10, further comprising: determining that a first physical sidelink channel and the second physical sidelink channel are time division multiplexed, the first physical sidelink channel comprises a physical sidelink shared channel and the second physical sidelink channel comprises a physical sidelink control channel, wherein the transport block size is based at least in part on determining that the first physical sidelink channel and the second physical sidelink channel are time division multiplexed.

Aspect 12: The method of aspect 11, further comprising: determining an overhead of the physical sidelink control channel per physical resource block based at least in part on determining that the first physical sidelink channel and the second physical sidelink channel are time division multiplexed, wherein the transport block size is based at least in part on the overhead of the physical sidelink control channel being per physical resource block.

Aspect 13: The method of any of aspects 11 through 12, further comprising: determining a number of symbols associated with the physical sidelink control channel or the physical sidelink shared channel, or both; determining a number of symbols exclusively including the physical sidelink control channel; and excluding the number of symbols exclusively including the physical sidelink control channel from the estimate number of resource elements associated with the physical resource block or the number of resource elements associated with the allocated physical resource blocks, or both, wherein the transport block size is based at least in part on the excluding.

Aspect 14: The method of any of aspects 11 through 13, wherein the transport block size is based at least in part on the overhead of the physical sidelink control channel being per slot.

Aspect 15: The method of any of aspects 3 through 14, further comprising: determining a number of resource elements for a second sidelink control information; and subtracting the number of resource elements for the second sidelink control information from the estimate number of resource elements associated with the physical resource block or the number of resource elements associated with the allocated physical resource blocks, or both, wherein the transport block size is based at least in part on the subtracting.

Aspect 16: The method of aspect 15, further comprising: determining a control overhead associated with the second sidelink control information based at least in part on a target code rate associated with a modulation coding scheme, wherein the transport block size is based at least in part on the control overhead associated with the second sidelink control information.

Aspect 17: The method of any of aspects 15 through 16, further comprising: determining a control overhead associated with the second sidelink control information; and ignoring the control overhead associated with the second sidelink control information, wherein the transport block size is based at least in part on ignoring the control overhead associated with the second sidelink control information.

Aspect 18: The method of any of aspects 15 through 17, further comprising: identifying a modulation coding scheme for the sidelink communications; and identifying a target code rate based at least in part on the modulation coding scheme for the sidelink communications, wherein determining the number of resource elements for the second sidelink control information is based at least in part on the target code rate.

Aspect 19: The method of any of aspects 15 through 18, wherein transmitting the sidelink information on the physical sidelink channel comprises: transmitting the second sidelink control information on a physical sidelink shared channel based at least in part on the transport block size.

Aspect 20: The method of any of aspects 3 through 19, further comprising: transmitting signaling comprising an indication of an overhead value, wherein determining the estimate number of resource elements associated with the physical resource block is based at least in part on the signaled overhead value.

Aspect 21: The method of any of aspects 3 through 20, further comprising: transmitting signaling comprising an indication of an offset overhead value relative to a demodulation reference signal pattern, wherein determining the estimate number of resource elements associated with the physical resource block is based at least in part on the signaled offset overhead value.

Aspect 22: The method of any of aspects 3 through 21, further comprising: adjusting the number of resource elements associated with the allocated physical resource blocks for the sidelink communications to a number of resource elements associated with the allocated physical resource blocks for non-sidelink communications.

Aspect 23: The method of any of aspects 3 through 22, further comprising: determining a channel state information reference signal overhead; and refraining from using the channel state information reference signal overhead from determining the estimate number of resource elements associated with the physical resource block or determining the number of resource elements associated with the allocated physical resource blocks, or both, wherein the transport block size is based at least in part on the ignoring.

Aspect 24: A method for wireless communication, comprising: decoding sidelink information for sidelink communications based on a TBS, and receiving the decoded sidelink information on a physical sidelink channel, the transport block size based at least in part on an overhead of a second physical sidelink channel for communicating the sidelink information.

Aspect 25: The method of aspect 24, further comprising: determining an estimate number of resource elements associated with a physical resource block for sidelink communications, wherein the transport block size is based at least in part on the estimate number of resource elements associated with the physical resource block.

Aspect 26: The method of aspect 25, further comprising: determining a number of allocated physical resource blocks for the sidelink communications; and determining a number of resource elements associated with the allocated physical resource blocks for the sidelink communications based at least in part on the number of allocated physical resource blocks or the estimate number of resource elements associated with the physical resource block, or both, wherein the transport block size is based at least in part on the number of resource elements associated with the allocated physical resource blocks for the sidelink communications.

Aspect 27: The method of aspect 26, further comprising: determining a number of resource elements for a first sidelink control information; and subtracting the number of resource elements for the first sidelink control information from the number of resource elements associated with the allocated physical resource blocks, wherein the transport block size is based at least in part on the subtracting.

Aspect 28: A method for wireless communication, comprising: identifying sidelink control information for sidelink communications; determining a transport block size for the sidelink control information; and transmitting the sidelink control information on a physical sidelink channel based at least in part on the transport block size.

Aspect 29: The method of aspect 28, further comprising: determining an estimate number of resource elements associated with a physical resource block for the sidelink communications, wherein determining the transport block size is based at least in part on the estimate number of resource elements associated with the physical resource block.

Aspect 30: The method of aspect 29, further comprising: determining a number of allocated physical resource blocks for the sidelink communications; and determining a number of resource elements associated with the physical resource block for the sidelink communications based at least in part on the number of allocated physical resource blocks or the estimate number of resource elements associated with the physical resource block, or both, wherein determining the transport block size is based at least in part on the number of resource elements associated with the physical resource block for the sidelink communications.

Aspect 31: The method of aspect 30, further comprising: determining a number of resource elements for a first sidelink control information; and subtracting the number of resource elements for the first sidelink control information from the estimate number of resource elements associated with the physical resource block or the number of resource elements associated with the physical resource block, or both, wherein determining the transport block size is based at least in part on the subtracting.

Aspect 32: The method of aspect 31, further comprising: determining control overhead associated with the first sidelink control information; and refraining from using the control overhead in the estimate number of resource elements associated with the physical resource block or the number of resource elements associated with the physical resource block, or both, wherein determining the transport block size is based at least in part on the refraining.

Aspect 33: The method of any of aspects 31 through 32, wherein transmitting the sidelink control information on the physical sidelink channel comprises: transmitting the first sidelink control information on a physical sidelink control channel based at least in part on the transport block size.

Aspect 34: The method of any of aspects 31 through 33, further comprising: determining that a first physical sidelink channel and a second physical sidelink channel are frequency division multiplexed, the first physical sidelink channel comprises a physical sidelink shared channel and the second physical sidelink channel comprises a physical sidelink control channel, wherein determining the transport block size is based at least in part on that the first physical sidelink channel and the second physical sidelink channel are frequency division multiplexed.

Aspect 35: The method of aspect 34, further comprising: determining that physical sidelink shared channel occupies the number of resource elements associated with the physical resource block; and scaling an overhead of the physical sidelink control channel by a value of the resource elements occupied by the physical sidelink shared channel.

Aspect 36: The method of any of aspects 31 through 35, wherein determining the transport block size is based at least in part on the overhead of the physical sidelink control channel per slot.

Aspect 37: The method of any of aspects 31 through 36, further comprising: determining that a first physical sidelink channel and a second physical sidelink channel are time division multiplexed, the first physical sidelink channel comprises a physical sidelink shared channel and the second physical sidelink channel comprises a physical sidelink control channel, wherein determining the transport block size is based at least in part on that the first physical sidelink channel and the second physical sidelink channel are time division multiplexed.

Aspect 38: The method of aspect 37, further comprising: determining an overhead of the physical sidelink control channel per physical resource block based at least in part on that the first sidelink channel and the second physical sidelink channel are time division multiplexed, wherein determining the transport block size is based at least in part on the overhead of the physical sidelink control channel per physical resource block.

Aspect 39: The method of any of aspects 37 through 38, further comprising: determining a number of symbols associated with the physical sidelink control channel or the physical sidelink shared channel, or both; determining a number of symbols exclusively including the physical sidelink control channel; and excluding the number of symbols exclusively including the physical sidelink control channel from the estimate number of resource elements associated with the physical resource block or the number of resource elements associated with the physical resource block, or both, wherein determining the transport block size is based at least in part on the excluding.

Aspect 40: The method of any of aspects 37 through 39, wherein determining the transport block size is based at least in part on an overhead of the physical sidelink control channel per slot.

Aspect 41: The method of any of aspects 30 through 40, further comprising: determining a number of resource elements for a second sidelink control information; and subtracting the number of resource elements for the second sidelink control information from the estimate number of resource elements associated with the physical resource block or the number of resource elements associated with the physical resource block, or both, wherein determining the transport block size is based at least in part on the subtracting.

Aspect 42: The method of aspect 41, further comprising: determining a control overhead associated with the second sidelink control information based at least in part on a target code rate associated with a modulation coding scheme, wherein determining the transport block size is based at least in part on the control overhead associated with the second sidelink control information.

Aspect 43: The method of any of aspects 41 through 42, further comprising: ignoring the control overhead associated with the second sidelink control information, wherein determining the transport block size is based at least in part on ignoring the control overhead associated with the second sidelink control information.

Aspect 44: The method of any of aspects 41 through 43, further comprising: identifying a modulation coding scheme for the second sidelink control information; and identifying a target code rate based at least in part on the modulation coding scheme for second sidelink control information, wherein determining the number of resource elements for the second sidelink control information is based at least in part on the target code rate.

Aspect 45: The method of any of aspects 41 through 44, wherein transmitting the sidelink control information on the physical sidelink channel comprises: transmitting the second sidelink control information on a physical sidelink shared channel based at least in part on the transport block size.

Aspect 46: The method of any of aspects 30 through 45, further comprising: transmitting signaling comprising an indication of an overhead value, wherein determining the estimate number of resource elements associated with the physical resource block is based at least in part on the signaled overhead value.

Aspect 47: The method of any of aspects 30 through 46, further comprising: transmitting signaling comprising an indication of an offset overhead value relative to a demodulation reference signal pattern, wherein determining the estimate number of resource elements associated with the physical resource block is based at least in part on the signaled offset overhead value.

Aspect 48: The method of any of aspects 30 through 47, further comprising: transmitting signaling comprising an indication of a number of symbols to use for the transport block size determination, wherein determining the transport block size is based at least in part on the signaling.

Aspect 49: The method of aspect 48, further comprising: determining a number of allocated symbols associated with the physical sidelink channel, the physical sidelink channel comprising a physical sidelink control channel; and subtracting the number of symbols to use for the transport block size determination from the number of allocated symbols associated with the physical sidelink channel, wherein determining the estimate number of resource elements associated with the physical resource block is based at least in part on the subtracting.

Aspect 50: The method of any of aspects 48 through 49, wherein determining the estimate number of resource elements associated with the physical resource block is based at least in part on the number of symbols to use for the transport block size determination.

Aspect 51: The method of any of aspects 30 through 50, further comprising: adjusting the number of resource elements associated with the physical resource block for the sidelink communications to a number of resource elements associated with the physical resource block for non-sidelink communications.

Aspect 52: The method of any of aspects 30 through 51, further comprising: determining a channel state information reference signal overhead; and refraining from using the channel state information reference signal overhead from determining the estimate number of resource elements associated with the physical resource block or determining the number of resource elements associated with the physical resource block, or both, wherein determining the transport block size is based at least in part on the ignoring.

Aspect 53: The method of any of aspects 29 through 52, further comprising: determining a number of subcarriers associated with the physical resource block, wherein determining the estimate number of resource elements associated with the physical resource block is based at least in part on the number of subcarriers associated with the physical resource block.

Aspect 54: The method of any of aspects 29 through 53, further comprising: determining a number of allocated symbols associated with a physical sidelink channel, wherein determining the estimate number of resource elements associated with the physical resource block is based at least in part on one or more of the number of subcarriers associated with the physical resource block and the number of allocated symbols associated with the physical sidelink channel.

Aspect 55: The method of any of aspects 29 through 54, further comprising: determining a demodulation reference signal overhead associated with the physical resource block, wherein determining the estimate number of resource elements associated with the physical resource block is based at least in part on the demodulation reference signal overhead associated with the physical resource block.

Aspect 56: The method of any of aspects 29 through 55, further comprising: determining control overhead associated with the physical resource block, wherein determining the estimate number of resource elements associated with the physical resource block is based at least in part on the control overhead associated with the physical resource block.

Aspect 57: The method of any of aspects 28 through 56, further comprising: determining an overhead of the physical sidelink channel based at least in part on a period of the physical sidelink channel, wherein determining the transport block size is based at least in part on the overhead of the physical sidelink channel.

Aspect 58: The method of aspect 57, wherein the physical sidelink channel comprises a physical sidelink feedback channel.

Aspect 59: The method of any of aspects 57 through 58, further comprising: scaling the overhead of the physical sidelink channel based at least in part on the period of the physical sidelink channel, wherein determining the transport block size is based at least in part on the scaling.

Aspect 60: The method of any of aspects 57 through 59, further comprising: determining an average of the overhead of the physical sidelink channel over the period of the physical sidelink channel, wherein determining the transport block size is based at least in part on the average of the overhead of the physical sidelink channel over the period of the physical sidelink channel.

Aspect 61: The method of any of aspects 57 through 60, further comprising: applying the overhead of the physical sidelink channel as a value per physical resource block, wherein determining the transport block size is based at least in part on the applying.

Aspect 62: The method of any of aspects 57 through 61, wherein the overhead of the physical sidelink channel corresponds to a number of available symbols of a second physical sidelink channel, the second physical sidelink channel comprising a physical sidelink shared channel.

Aspect 63: The method of any of aspects 28 through 62, wherein the physical sidelink channel comprises a physical sidelink shared channel.

Aspect 64: The method of any of aspects 28 through 63, wherein the physical sidelink channel comprises a physical sidelink control channel.

Aspect 65: A method for wireless communication, comprising: identifying sidelink control information for sidelink communications; determining a transport block size for the sidelink control information; and receiving the sidelink control information on a physical sidelink channel based at least in part on the transport block size.

Aspect 66: The method of aspect 65, further comprising: determining an estimate number of resource elements associated with a physical resource block for the sidelink communications, wherein determining the transport block size is based at least in part on the estimate number of resource elements associated with the physical resource block.

Aspect 67: The method of aspect 66, further comprising: determining a number of allocated physical resource blocks for the sidelink communications; and determining a number of resource elements associated with the physical resource block for the sidelink communications based at least in part on the number of allocated physical resource blocks or the estimate number of resource elements associated with the physical resource block, or both, wherein determining the transport block size is based at least in part on the number of resource elements associated with the physical resource block for the sidelink communications.

Aspect 68: The method of aspect 67, further comprising: determining a number of resource elements for a first sidelink control information; and subtracting the number of resource elements for the first sidelink control information from the estimate number of resource elements associated with the physical resource block or the number of resource elements associated with the physical resource block, or both, wherein determining the transport block size is based at least in part on the subtracting.

Aspect 69: The method of aspect 68, further comprising: determining control overhead associated with the first sidelink control information; and refraining from using the control overhead in the estimate number of resource elements associated with the physical resource block or the number of resource elements associated with the physical resource block, or both, wherein determining the transport block size is based at least in part on the refraining.

Aspect 70: The method of any of aspects 68 through 69, wherein receiving the sidelink control information on the physical sidelink channel comprises: receiving the first sidelink control information on a physical sidelink control channel based at least in part on the transport block size.

Aspect 71: The method of any of aspects 68 through 70, further comprising: determining that a first physical sidelink channel and a second physical sidelink channel are frequency division multiplexed, the first physical sidelink channel comprises a physical sidelink shared channel and the second physical sidelink channel comprises a physical sidelink control channel, wherein determining the transport block size is based at least in part on that the first physical sidelink channel and the second physical sidelink channel are frequency division multiplexed.

Aspect 72: The method of any of aspects 68 through 71, further comprising: determining that physical sidelink shared channel occupies the number of resource elements associated with the physical resource block; and scaling an overhead of the physical sidelink control channel by a value of the resource elements occupied by the physical sidelink shared channel.

Aspect 73: The method of any of aspects 68 through 72, wherein determining the transport block size is based at least in part on the overhead of the physical sidelink control channel per slot.

Aspect 74: The method of any of aspects 68 through 73, further comprising: determining that a first physical sidelink channel and a second physical sidelink channel are time division multiplexed, the first physical sidelink channel comprises a physical sidelink shared channel and the second physical sidelink channel comprises a physical sidelink control channel, wherein determining the transport block size is based at least in part on that the first physical sidelink channel and the second physical sidelink channel are time division multiplexed.

Aspect 75: The method of aspect 74, further comprising: determining an overhead of the physical sidelink control channel per physical resource block based at least in part on that the first sidelink channel and the second physical sidelink channel are time division multiplexed, wherein determining the transport block size is based at least in part on the overhead of the physical sidelink control channel per physical resource block.

Aspect 76: The method of any of aspects 74 through 75, further comprising: determining a number of symbols associated with the physical sidelink control channel or the physical sidelink shared channel, or both; determining a number of symbols exclusively including the physical sidelink control channel; and excluding the number of symbols exclusively including the physical sidelink control channel from the estimate number of resource elements associated with the physical resource block or the number of resource elements associated with the physical resource block, or both, wherein determining the transport block size is based at least in part on the excluding.

Aspect 77: The method of any of aspects 74 through 76, wherein determining the transport block size is based at least in part on an overhead of the physical sidelink control channel per slot.

Aspect 78: The method of any of aspects 67 through 77, further comprising: determining a number of resource elements for a second sidelink control information; and subtracting the number of resource elements for the second sidelink control information from the estimate number of resource elements associated with the physical resource block or the number of resource elements associated with the physical resource block, or both, wherein determining the transport block size is based at least in part on the subtracting.

Aspect 79: The method of aspect 78, further comprising: determining a control overhead associated with the second sidelink control information based at least in part on a target code rate associated with a modulation coding scheme, wherein determining the transport block size is based at least in part on the control overhead associated with the second sidelink control information.

Aspect 80: The method of any of aspects 78 through 79, further comprising: ignoring the control overhead associated with the second sidelink control information, wherein determining the transport block size is based at least in part on ignoring the control overhead associated with the second sidelink control information.

Aspect 81: The method of any of aspects 78 through 80, further comprising: identifying a modulation coding scheme for the second sidelink control information; and identifying a target code rate based at least in part on the modulation coding scheme for second sidelink control information, wherein determining the number of resource elements for the second sidelink control information is based at least in part on the target code rate.

Aspect 82: The method of any of aspects 78 through 81, wherein receiving the sidelink control information on the physical sidelink channel comprises: receiving the second sidelink control information on a physical sidelink shared channel based at least in part on the transport block size.

Aspect 83: The method of any of aspects 67 through 82, further comprising: receiving signaling comprising an indication of an overhead value, wherein determining the estimate number of resource elements associated with the physical resource block is based at least in part on the signaled overhead value.

Aspect 84: The method of any of aspects 67 through 83, further comprising: receiving signaling comprising an indication of an offset overhead value relative to a demodulation reference signal pattern, wherein determining the estimate number of resource elements associated with the physical resource block is based at least in part on the signaled offset overhead value.

Aspect 85: The method of any of aspects 67 through 84, further comprising: receiving signaling comprising an indication of a number of symbols to use for the transport block size determination, wherein determining the transport block size is based at least in part on the signaling.

Aspect 86: The method of aspect 85, further comprising: determining a number of allocated symbols associated with the physical sidelink channel, the physical sidelink channel comprising a physical sidelink control channel; and subtracting the number of symbols to use for the transport block size determination from the number of allocated symbols associated with the physical sidelink channel, wherein determining the estimate number of resource elements associated with the physical resource block is based at least in part on the subtracting.

Aspect 87: The method of any of aspects 85 through 86, wherein determining the estimate number of resource elements associated with the physical resource block is based at least in part on the number of symbols to use for the transport block size determination.

Aspect 88: The method of any of aspects 67 through 87, further comprising: adjusting the number of resource elements associated with the physical resource block for the sidelink communications to a number of resource elements associated with the physical resource block for non-sidelink communications.

Aspect 89: The method of any of aspects 67 through 88, further comprising: determining a channel state information reference signal overhead; and refraining from using the channel state information reference signal overhead from determining the estimate number of resource elements associated with the physical resource block or determining the number of resource elements associated with the physical resource block, or both, wherein determining the transport block size is based at least in part on the ignoring.

Aspect 90: The method of any of aspects 66 through 89, further comprising: determining a number of subcarriers associated with the physical resource block, wherein determining the estimate number of resource elements associated with the physical resource block is based at least in part on the number of subcarriers associated with the physical resource block.

Aspect 91: The method of any of aspects 66 through 90, further comprising: determining a number of allocated symbols associated with a physical sidelink channel, wherein determining the estimate number of resource elements associated with the physical resource block is based at least in part on one or more of the number of subcarriers associated with the physical resource block and the number of allocated symbols associated with the physical sidelink channel.

Aspect 92: The method of any of aspects 66 through 91, further comprising: determining a demodulation reference signal overhead associated with the physical resource block, wherein determining the estimate number of resource elements associated with the physical resource block is based at least in part on the demodulation reference signal overhead associated with the physical resource block.

Aspect 93: The method of any of aspects 66 through 92, further comprising: determining control overhead associated with the physical resource block, wherein determining the estimate number of resource elements associated with the physical resource block is based at least in part on the control overhead associated with the physical resource block.

Aspect 94: The method of any of aspects 65 through 93, further comprising: determining an overhead of the physical sidelink channel based at least in part on a period of the physical sidelink channel, wherein determining the transport block size is based at least in part on the overhead of the physical sidelink channel.

Aspect 95: The method of aspect 94, wherein the physical sidelink channel comprises a physical sidelink feedback channel.

Aspect 96: The method of any of aspects 94 through 95, further comprising: scaling the overhead of the physical sidelink channel based at least in part on the period of the physical sidelink channel, wherein determining the transport block size is based at least in part on the scaling.

Aspect 97: The method of any of aspects 94 through 96, further comprising: determining an average of the overhead of the physical sidelink channel over the period of the physical sidelink channel, wherein determining the transport block size is based at least in part on the average of the overhead of the physical sidelink channel over the period of the physical sidelink channel.

Aspect 98: The method of any of aspects 94 through 97, further comprising: applying the overhead of the physical sidelink channel as a value per physical resource block, wherein determining the transport block size is based at least in part on the applying.

Aspect 99: The method of any of aspects 94 through 98, wherein the overhead of the physical sidelink channel corresponds to a number of available symbols of a second physical sidelink channel, the second physical sidelink channel comprising a physical sidelink shared channel.

Aspect 100: The method of any of aspects 65 through 99, wherein the physical sidelink channel comprises a physical sidelink shared channel.

Aspect 101: The method of any of aspects 65 through 100, wherein the physical sidelink channel comprises a physical sidelink control channel.

Aspect 102: A method for wireless communication, comprising: allocating resources for sidelink communications on a physical sidelink channel; transmitting, based at least in part on the allocating, signaling comprising an indication of the resources for the sidelink communications; and receiving sidelink control information on the physical sidelink channel based at least in part on the signaling, wherein transport block size for the sidelink control information is determined based at least in part on the indication of the resources for the sidelink communications.

Aspect 103: The method of aspect 102, wherein transmitting the signaling comprises: transmitting signaling comprising an indication of an overhead value, wherein an estimate number of resource elements associated with a physical resource block for the sidelink communications is based at least in part on the signaled overhead value.

Aspect 104: The method of any of aspects 102 through 103, wherein transmitting the signaling comprises: transmitting signaling comprising an indication of a number of symbols to use for the transport block size determination, wherein the transport block size is based at least in part on the number of symbols to use for the transport block size determination.

Aspect 105: The method of any of aspects 102 through 104, wherein the physical sidelink channel comprises a physical sidelink shared channel.

Aspect 106: The method of any of aspects 102 through 105, wherein the physical sidelink channel comprises a physical sidelink control channel.

Aspect 107: An apparatus for wireless communication, comprising a processor; and memory coupled with the processor, the processor and memory configured to perform a method of any of aspects 1 through 23.

Aspect 108: An apparatus for wireless communication, comprising at least one means for performing a method of any of aspects 1 through 23.

Aspect 110: An apparatus for wireless communication, comprising a processor; and memory coupled with the processor, the processor and memory configured to perform a method of any of aspects 24 through 27.

Aspect 111: An apparatus for wireless communication, comprising at least one means for performing a method of any of aspects 24 through 27.

Aspect 113: An apparatus for wireless communication, comprising a processor; and memory coupled with the processor, the processor and memory configured to perform a method of any of aspects 28 through 64.

Aspect 114: An apparatus for wireless communication, comprising at least one means for performing a method of any of aspects 28 through 64.

Aspect 116: An apparatus for wireless communication, comprising a processor; and memory coupled with the processor, the processor and memory configured to perform a method of any of aspects 65 through 101.

Aspect 117: An apparatus for wireless communication, comprising at least one means for performing a method of any of aspects 65 through 101.

Aspect 119: An apparatus for wireless communication, comprising a processor; and memory coupled with the processor, the processor and memory configured to perform a method of any of aspects 102 through 106.

Aspect 120: An apparatus for wireless communication, comprising at least one means for performing a method of any of aspects 102 through 106.

Aspect 121: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform a method of any of aspects 102 through 106.