Sidelink sync block transmission in shared spectrum

Abstract

Methods, systems, and devices for wireless communications are described. In general, the described techniques provide for efficiently identifying resources for transmitting one or more sidelink synchronization signal blocks (S-SSBs) in a shared spectrum or efficiently beam sweeping multiple S-SSBs in a shared spectrum. In one aspect, a user equipment (UE) may transmit an S-SSB in a sidelink bandwidth part (BWP) in a shared spectrum such that a lower edge of the S-SSB is aligned with or offset from a lower edge of the sidelink BWP. In another aspect, the UE may beam sweep the S-SSBs in one or more S-SSB bursts in an S-SSB period to increase the chance that another UE can receive the S-SSB. In yet another aspect, resources allocated for S-SSB transmissions may facilitate flexible S-SSB transmissions while minimizing gaps to prevent other UEs from erroneously determining that a sidelink BWP in a shared spectrum is clear for transmission.

Description

Technical Field

[0001] The following relates generally to wireless communications, and more particularly to sidelink synchronization signal block (S-SSB) transmissions in a shared spectrum.

[0002] introduction

[0003] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, broadcast, etc. These systems may be able to support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of such multiple access systems include fourth generation (4G) systems (such as long term evolution (LTE) systems, advanced LTE (LTE-A) systems, or LTE-A Pro systems), and fifth generation (5G) systems, which may be referred to as new radio (NR) systems. These systems may employ various technologies, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM).

[0004] A wireless multiple access communication system may include several base stations or network access nodes, each of which simultaneously supports communication for multiple communication devices, which may be further referred to as user equipment (UE). Some wireless communication systems may support sidelink communications between UEs on a shared spectrum. In such a system, a UE may have to contend for access to a shared spectrum to transmit a sidelink signal to another UE. For example, a UE may perform a listen-before-talk (LBT) procedure to gain access to a sidelink BWP to transmit a sidelink synchronization signal block (S-SSB) on the sidelink BWP. Improved techniques for supporting S-SSB transmissions in a shared spectrum may be required.

[0005] Overview

[0006] The present disclosure relates to methods, systems, devices, and apparatuses that support transmission of sidelink synchronization signal blocks (S-SSBs) in a shared spectrum. In general, the described techniques provide for efficiently identifying resources for transmitting one or more S-SSBs in a shared spectrum or efficiently beam sweeping multiple S-SSBs in a shared spectrum. In one aspect, a user equipment (UE) may transmit an S-SSB in a sidelink bandwidth part (BWP) in a shared spectrum so that the lower edge of the S-SSB is aligned with or offset from the lower edge of the sidelink BWP. On the other hand, the UE may beam sweep the S-SSBs in one or more S-SSB bursts in an S-SSB period to increase the chance that another UE can receive the S-SSB. On yet another aspect, resources allocated for S-SSB transmissions may facilitate flexible S-SSB transmissions while minimizing gaps to prevent other UEs from erroneously determining that the sidelink BWP in the shared spectrum is clear for transmission.

[0007] A method of wireless communication at a UE is described. The method may include: performing a listen-before-talk procedure to obtain access to a sidelink bandwidth portion of a shared spectrum for sidelink communication; identifying a sidelink synchronization signal block to be transmitted in the sidelink bandwidth portion; and transmitting the sidelink synchronization signal block in the sidelink bandwidth portion such that a first starting resource block of the sidelink synchronization signal block is offset from a second starting resource block of the sidelink bandwidth portion.

[0008] An apparatus for wireless communication at a UE is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to: perform a listen-before-talk procedure to obtain access to a sidelink bandwidth portion for sidelink communication in a shared spectrum; identify a sidelink synchronization signal block to be transmitted in the sidelink bandwidth portion; and transmit the sidelink synchronization signal block in the sidelink bandwidth portion such that a first starting resource block of the sidelink synchronization signal block is offset from a second starting resource block of the sidelink bandwidth portion.

[0009] Another apparatus for wireless communication at a UE is described. The apparatus may include means for performing a listen-before-talk procedure to obtain access to a sidelink bandwidth portion of a shared spectrum for sidelink communications; identifying a sidelink synchronization signal block to be transmitted in the sidelink bandwidth portion; and transmitting the sidelink synchronization signal block in the sidelink bandwidth portion such that a first starting resource block of the sidelink synchronization signal block is offset from a second starting resource block of the sidelink bandwidth portion.

[0010] A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to: perform a listen-before-talk procedure to obtain access to a sidelink bandwidth portion for sidelink communication in a shared spectrum; identify a sidelink synchronization signal block to be transmitted in the sidelink bandwidth portion; and transmit the sidelink synchronization signal block in the sidelink bandwidth portion such that a first starting resource block of the sidelink synchronization signal block is offset from a second starting resource block of the sidelink bandwidth portion.

[0011] Some examples of the methods, apparatuses (devices), and non-transient computer-readable media described herein may further include operations, features, devices, or instructions for the following actions: transmitting an indication of an offset between a first starting resource block of the side link synchronization signal block and a second starting resource block of the side link bandwidth portion in a master information block. In some examples of the methods, apparatuses (devices), and non-transient computer-readable media described herein, the side link synchronization signal block shares the same synchronization grid as the downlink synchronization signal block in the shared spectrum. In some examples of the methods, apparatuses (devices), and non-transient computer-readable media described herein, the second starting resource block of the side link bandwidth portion includes an index of zero.

[0012] A method for wireless communication at a UE is described. The method may include: identifying a sidelink bandwidth portion of a shared spectrum that includes a sidelink synchronization signal block; receiving a master information block indicating an offset between a first starting resource block of the sidelink synchronization signal block and a second starting resource block of the sidelink bandwidth portion; and decoding the sidelink synchronization signal block in the sidelink bandwidth portion based on receiving the master information block indicating the offset.

[0013] An apparatus for wireless communication at a UE is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to: identify a sidelink bandwidth portion of a shared spectrum that includes a sidelink synchronization signal block; receive a master information block indicating an offset between a first starting resource block of the sidelink synchronization signal block and a second starting resource block of the sidelink bandwidth portion; and decode the sidelink synchronization signal block in the sidelink bandwidth portion based on receiving the master information block indicating the offset.

[0014] Another apparatus for wireless communication at a UE is described. The apparatus may include means for: identifying a sidelink bandwidth portion of a shared spectrum that includes a sidelink synchronization signal block; receiving a master information block indicating an offset between a first starting resource block of the sidelink synchronization signal block and a second starting resource block of the sidelink bandwidth portion; and decoding the sidelink synchronization signal block in the sidelink bandwidth portion based on receiving the master information block indicating the offset.

[0015] A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to: identify a sidelink bandwidth portion of a shared spectrum that includes a sidelink synchronization signal block; receive a master information block indicating an offset between a first starting resource block of the sidelink synchronization signal block and a second starting resource block of the sidelink bandwidth portion; and decode the sidelink synchronization signal block in the sidelink bandwidth portion based on receiving the master information block indicating the offset.

[0016] In some examples of the methods, apparatuses (devices), and non-transient computer-readable media described herein, the sidelink synchronization signal block shares the same synchronization grid as the downlink synchronization signal block in the shared spectrum. In some examples of the methods, apparatuses (devices), and non-transient computer-readable media described herein, the index of the second starting resource block of the sidelink bandwidth portion can be zero.

[0017] A method of wireless communication at a UE is described. The method may include: performing a listen-before-talk procedure to obtain access to a sidelink bandwidth portion of a shared spectrum for sidelink communication; identifying a sidelink synchronization signal block to be transmitted in the sidelink bandwidth portion; and transmitting the sidelink synchronization signal block in the sidelink bandwidth portion such that the sidelink synchronization signal block shares a same starting resource block with the sidelink bandwidth portion.

[0018] An apparatus for wireless communication at a UE is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to: perform a listen-before-talk procedure to obtain access to a sidelink bandwidth portion for sidelink communication in a shared spectrum; identify a sidelink synchronization signal block to be transmitted in the sidelink bandwidth portion; and transmit the sidelink synchronization signal block in the sidelink bandwidth portion so that the sidelink synchronization signal block shares a same starting resource block with the sidelink bandwidth portion.

[0019] Another apparatus for wireless communication at a UE is described. The apparatus may include means for performing a listen-before-talk procedure to obtain access to a sidelink bandwidth portion of a shared spectrum for sidelink communication; identifying a sidelink synchronization signal block to be transmitted in the sidelink bandwidth portion; and transmitting the sidelink synchronization signal block in the sidelink bandwidth portion such that the sidelink synchronization signal block shares a same starting resource block with the sidelink bandwidth portion.

[0020] A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to: perform a listen-before-talk procedure to obtain access to a sidelink bandwidth portion for sidelink communication in a shared spectrum; identify a sidelink synchronization signal block to be transmitted in the sidelink bandwidth portion; and transmit the sidelink synchronization signal block in the sidelink bandwidth portion such that the sidelink synchronization signal block shares a same starting resource block with the sidelink bandwidth portion.

[0021] In some examples of the methods, apparatuses (devices), and non-transient computer-readable media described herein, the first synchronization grid of the sidelink synchronization signal block may be different from the second synchronization grid of the downlink synchronization signal block in the shared spectrum. In some examples of the methods, apparatuses (devices), and non-transient computer-readable media described herein, the index of the same starting resource block of the sidelink synchronization signal block and the sidelink bandwidth portion may be zero.

[0022] A method for wireless communication at a UE is described. The method may include: performing a listen-before-talk procedure to obtain access to a sidelink bandwidth portion in a shared spectrum for a sidelink synchronization signal block period; identifying a sidelink synchronization signal block burst to be transmitted in the sidelink synchronization signal block period, the sidelink synchronization signal block burst comprising two or more sidelink synchronization signal blocks; and transmitting each of the two or more sidelink synchronization signal blocks of the sidelink synchronization signal block burst using a different beam, wherein the two or more sidelink synchronization signal blocks in the sidelink synchronization signal block burst are transmitted in contiguous time resources.

[0023] An apparatus for wireless communication at a UE is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to: perform a listen-before-talk procedure to obtain access to a sidelink bandwidth portion in a shared spectrum for a sidelink synchronization signal block period; identify a sidelink synchronization signal block burst to be transmitted in the sidelink synchronization signal block period, the sidelink synchronization signal block burst comprising two or more sidelink synchronization signal blocks; and transmit each of the two or more sidelink synchronization signal blocks of the sidelink synchronization signal block burst using a different beam, wherein the two or more sidelink synchronization signal blocks in the sidelink synchronization signal block burst are transmitted in contiguous time resources.

[0024] Another apparatus for wireless communication at a UE is described. The apparatus may include means for performing a listen-before-talk procedure to obtain access to a sidelink bandwidth portion in a shared spectrum for a sidelink synchronization signal block period; identifying a sidelink synchronization signal block burst to be transmitted in the sidelink synchronization signal block period, the sidelink synchronization signal block burst including two or more sidelink synchronization signal blocks; and transmitting each of the two or more sidelink synchronization signal blocks of the sidelink synchronization signal block burst using a different beam, wherein the two or more sidelink synchronization signal blocks in the sidelink synchronization signal block burst are transmitted in contiguous time resources.

[0025] A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to perform the following operations: perform a listen-before-talk procedure to obtain access to a sidelink bandwidth portion in a shared spectrum for a sidelink synchronization signal block period; identify a sidelink synchronization signal block burst to be transmitted in the sidelink synchronization signal block period, the sidelink synchronization signal block burst including two or more sidelink synchronization signal blocks; and transmit each of the two or more sidelink synchronization signal blocks of the sidelink synchronization signal block burst using a different beam, wherein the two or more sidelink synchronization signal blocks in the sidelink synchronization signal block burst are transmitted in contiguous time resources.

[0026] Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, devices, or instructions for the following actions: identifying a beam for transmitting a side link synchronization signal block in the two or more side link synchronization signal blocks; and encoding at least a portion of a demodulation reference signal scrambling sequence included with the side link synchronization signal block based on a beam index of the identified beam. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, decoding at least a portion of the demodulation reference signal may include operations, features, devices, or instructions for the following: setting an initialization seed for encoding according to a beam index of the identified beam. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the number of the two or more side link synchronization signal blocks corresponds to a subcarrier spacing of the side link bandwidth portion.

[0027] A method of wireless communication at a UE is described. The method may include: identifying a sidelink synchronization signal block period having a sidelink synchronization signal block burst including two or more sidelink synchronization signal blocks, each sidelink synchronization signal block being transmitted using a different beam; and receiving the sidelink synchronization signal block burst including the two or more sidelink synchronization signal blocks in a contiguous time resource.

[0028] An apparatus for wireless communication at a UE is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to: identify a sidelink synchronization signal block period having a sidelink synchronization signal block burst including two or more sidelink synchronization signal blocks (each sidelink synchronization signal block is transmitted using a different beam); and receive a sidelink synchronization signal block burst including two or more sidelink synchronization signal blocks in a contiguous time resource.

[0029] Another apparatus for wireless communication at a UE is described. The apparatus may include means for: identifying a sidelink synchronization signal block period having a sidelink synchronization signal block burst including two or more sidelink synchronization signal blocks, each sidelink synchronization signal block being transmitted using a different beam; and receiving a sidelink synchronization signal block burst including two or more sidelink synchronization signal blocks in a contiguous time resource.

[0030] A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to: identify a sidelink synchronization signal block period having a sidelink synchronization signal block burst including two or more sidelink synchronization signal blocks, each of which is transmitted using a different beam; and receive a sidelink synchronization signal block burst including two or more sidelink synchronization signal blocks in a contiguous time resource.

[0031] Some examples of the methods, apparatus (devices) and non-transitory computer-readable media described herein may further include operations, features, apparatus or instructions for: receiving a demodulation reference signal scrambling sequence together with a side link synchronization signal block in the two or more side link synchronization signal blocks; and blindly decoding at least a portion of the demodulation reference signal scrambling sequence to identify a beam index of a beam used to transmit the side link synchronization signal block.

[0032] A method for wireless communication at a UE is described. The method may include: performing a listen-before-talk procedure to obtain access to a sidelink bandwidth portion in a shared spectrum for a sidelink synchronization signal block period; identifying a set of sidelink synchronization signal block bursts to be transmitted in the sidelink synchronization signal block period, each sidelink synchronization signal block burst including two or more sidelink synchronization signal blocks; and transmitting each of the two or more sidelink synchronization signal blocks in each sidelink synchronization signal block burst in the sidelink synchronization signal block period using a different beam.

[0033] An apparatus for wireless communication at a UE is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to: perform a listen-before-talk procedure to obtain access to a sidelink bandwidth portion in a shared spectrum for a sidelink synchronization signal block period; identify a set of sidelink synchronization signal block bursts to be transmitted in the sidelink synchronization signal block period, each sidelink synchronization signal block burst including two or more sidelink synchronization signal blocks; and transmit each of the two or more sidelink synchronization signal blocks in each sidelink synchronization signal block burst in the sidelink synchronization signal block period using a different beam.

[0034] Another apparatus for wireless communication at a UE is described. The apparatus may include means for performing a listen-before-talk procedure to obtain access to a sidelink bandwidth portion in a shared spectrum for a sidelink synchronization signal block period; identifying a set of sidelink synchronization signal block bursts to be transmitted in the sidelink synchronization signal block period, each sidelink synchronization signal block burst including two or more sidelink synchronization signal blocks; and transmitting each of the two or more sidelink synchronization signal blocks in each sidelink synchronization signal block burst in the sidelink synchronization signal block period using a different beam.

[0035] A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to perform the following operations: perform a listen-before-talk procedure to obtain access to a sidelink bandwidth portion in a shared spectrum for a sidelink synchronization signal block period; identify a set of sidelink synchronization signal block bursts to be transmitted in the sidelink synchronization signal block period, each sidelink synchronization signal block burst including two or more sidelink synchronization signal blocks; and transmit each of the two or more sidelink synchronization signal blocks in each sidelink synchronization signal block burst using a different beam in the sidelink synchronization signal block period.

[0036] Some examples of the methods, apparatus (devices), and non-transitory computer-readable media described herein may further include the following operations, features, apparatuses, or instructions: selecting a side link time interval for each side link synchronization signal block burst in the side link synchronization signal block burst set so that the side link synchronization signal block burst set can be non-overlapping in the side link synchronization signal block period, wherein the side link time interval corresponds to the time interval between each of two or more side link synchronization signal blocks in each side link synchronization signal block burst.

[0037] Some examples of the methods, apparatuses (devices) and non-transitory computer-readable media described herein may further include operations, features, devices or instructions for the following actions: identifying a beam for transmitting a side link synchronization signal block in a side link synchronization signal block burst in the side link synchronization signal block burst set; and encoding at least a portion of a demodulation reference signal scrambling sequence included with the side link synchronization signal block based on a beam index of the identified beam. In some examples of the methods, apparatuses (devices) and non-transitory computer-readable media described herein, decoding at least a portion of the demodulation reference signal may include operations, features, devices or instructions for the following: setting an initialization seed for encoding according to a beam index of the identified beam. In some examples of the methods, apparatuses (devices) and non-transitory computer-readable media described herein, the number of two or more side link synchronization signal blocks in each side link synchronization signal block burst corresponds to a subcarrier spacing of the side link bandwidth portion.

[0038] A method for wireless communication at a UE is described. The method may include: identifying a sidelink synchronization signal block period having a set of sidelink synchronization signal block bursts, each sidelink synchronization signal block burst including two or more sidelink synchronization signal blocks, and each of the two or more sidelink synchronization signal blocks is transmitted using a different beam; and receiving the set of sidelink synchronization signal block bursts in the sidelink synchronization signal block period.

[0039] An apparatus for wireless communication at a UE is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to: identify a sidelink synchronization signal block period having a set of sidelink synchronization signal block bursts, each sidelink synchronization signal block burst including two or more sidelink synchronization signal blocks, and each of the two or more sidelink synchronization signal blocks is transmitted using a different beam; and receive the sidelink synchronization signal block burst set in the sidelink synchronization signal block period.

[0040] Another apparatus for wireless communication at a UE is described. The apparatus may include means for: identifying a sidelink synchronization signal block period having a set of sidelink synchronization signal block bursts, each sidelink synchronization signal block burst including two or more sidelink synchronization signal blocks, and each of the two or more sidelink synchronization signal blocks is transmitted using a different beam; and receiving the set of sidelink synchronization signal block bursts in the sidelink synchronization signal block period.

[0041] A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor for the following operations: identifying a sidelink synchronization signal block period having a set of sidelink synchronization signal block bursts, each sidelink synchronization signal block burst including two or more sidelink synchronization signal blocks, and each of the two or more sidelink synchronization signal blocks is transmitted using a different beam; and receiving the sidelink synchronization signal block burst set in the sidelink synchronization signal block period.

[0042] Some examples of the methods, apparatus (devices) and non-transitory computer-readable media described herein may further include operations, features, apparatus or instructions for the following actions: receiving a demodulation reference signal scrambling sequence together with a side link synchronization signal block in a side link synchronization signal block burst in a side link synchronization signal block burst set; and blindly decoding at least a portion of the demodulation reference signal scrambling sequence to identify a beam index for transmitting the side link synchronization signal block.

[0043] A method of wireless communication at a UE is described. The method may include: identifying a discovery reference signal (DRS) window in a shared spectrum that includes a set of starting positions for transmitting one or more sidelink synchronization signal blocks; performing a listen-before-talk procedure to obtain access to the discovery reference signal window in the shared spectrum; and after obtaining access to the discovery reference signal window in the shared spectrum, transmitting the one or more sidelink synchronization signal blocks at a first starting position in the set of starting positions.

[0044] An apparatus for wireless communication at a UE is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to: identify a discovery reference signal (DRS) window in a shared spectrum that includes a set of starting positions for transmitting one or more side link synchronization signal blocks; perform a listen-before-talk procedure to obtain access to the discovery reference signal window in the shared spectrum; and after obtaining access to the discovery reference signal window in the shared spectrum, transmit the one or more side link synchronization signal blocks at a first starting position in the set of starting positions.

[0045] Another apparatus for wireless communication at a UE is described. The apparatus may include means for: identifying a discovery reference signal (DRS) window in a shared spectrum that includes a set of starting positions for transmitting one or more sidelink synchronization signal blocks; performing a listen-before-talk procedure to obtain access to the discovery reference signal window in the shared spectrum; and after obtaining access to the discovery reference signal window in the shared spectrum, transmitting the one or more sidelink synchronization signal blocks at a first starting position in the set of starting positions.

[0046] A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to: identify a discovery reference signal (DRS) window in a shared spectrum that includes a set of starting positions for transmitting one or more side link synchronization signal blocks; perform a listen-before-talk procedure to obtain access to the discovery reference signal window in the shared spectrum; and after obtaining access to the discovery reference signal window in the shared spectrum, transmit the one or more side link synchronization signal blocks at a first starting position in the set of starting positions.

[0047] In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, transmitting the one or more sidelink synchronization signal blocks may include operations, features, means, or instructions for the following actions: transmitting a sidelink synchronization signal block in the one or more sidelink synchronization signal blocks and an indication of a time slot including the synchronization signal block in a physical sidelink broadcast channel. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, transmitting the one or more sidelink synchronization signal blocks may include operations, features, means, or instructions for the following actions: transmitting a sidelink synchronization signal block in the one or more sidelink synchronization signal blocks and a demodulation reference signal scrambling sequence indicating a beam index of a beam used to transmit the synchronization signal block in a physical sidelink broadcast channel.

[0048] A method for wireless communication at a UE is described. The method may include: identifying a discovery reference signal (DRS) window in a shared spectrum in which to receive one or more sidelink synchronization signal blocks; determining that the discovery reference signal window includes a set of starting positions for receiving the one or more sidelink synchronization signal blocks; and monitoring the set of starting positions for finding the one or more sidelink synchronization signal blocks in the discovery reference signal window.

[0049] An apparatus for wireless communication at a UE is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to: identify a discovery reference signal (DRS) window in a shared spectrum in which one or more side link synchronization signal blocks are to be received; determine that the discovery reference signal window includes a set of starting positions for receiving one or more side link synchronization signal blocks; and monitor the set of starting positions to find one or more side link synchronization signal blocks in the discovery reference signal window.

[0050] Another apparatus for wireless communication at a UE is described. The apparatus may include means for: identifying a discovery reference signal (DRS) window in a shared spectrum in which to receive one or more sidelink synchronization signal blocks; determining that the discovery reference signal window includes a set of starting positions for receiving the one or more sidelink synchronization signal blocks; and monitoring the set of starting positions for finding the one or more sidelink synchronization signal blocks in the discovery reference signal window.

[0051] A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to: identify a discovery reference signal (DRS) window in a shared spectrum in which to receive one or more side link synchronization signal blocks; determine that the discovery reference signal window includes a set of starting positions for receiving the one or more side link synchronization signal blocks; and monitor the set of starting positions to find the one or more side link synchronization signal blocks in the discovery reference signal window.

[0052] Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for the following actions: receiving a sidelink synchronization signal block in the one or more sidelink synchronization signal blocks and an indication of a time slot including the synchronization signal block in a physical sidelink broadcast channel. Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for the following actions: receiving a sidelink synchronization signal block in the one or more sidelink synchronization signal blocks and a demodulation reference signal scrambling sequence indicating a beam index of a beam used to transmit the synchronization signal block in a physical sidelink broadcast channel.

[0053] A method for wireless communication at a UE is described. The method may include: identifying a first sidelink synchronization signal block to be transmitted in a first time slot and a second sidelink synchronization signal block to be transmitted in a second time slot in a sidelink bandwidth portion of a shared spectrum; generating a physical broadcast channel (PBCH) repetition or cyclic prefix extension to fill a gap between the first sidelink synchronization signal block and the second sidelink synchronization signal block; and transmitting the first sidelink synchronization signal block in the first time slot and transmitting the second sidelink synchronization signal block in the second time slot together with a physical broadcast channel repetition or cyclic prefix extension between the first sidelink synchronization signal block and the second sidelink synchronization signal block.

[0054] A device for wireless communication at a UE is described. The device may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the device to: identify a first side link synchronization signal block to be transmitted in a first time slot and a second side link synchronization signal block to be transmitted in a second time slot in a side link bandwidth portion of a shared spectrum; generate a physical broadcast channel (PBCH) repetition or cyclic prefix extension to fill a gap between the first side link synchronization signal block and the second side link synchronization signal block; and transmit the first side link synchronization signal block in the first time slot and transmit the second side link synchronization signal block in the second time slot together with a physical broadcast channel repetition or cyclic prefix extension between the first side link synchronization signal block and the second side link synchronization signal block.

[0055] Another apparatus for wireless communication at a UE is described. The apparatus may include means for: identifying a first sidelink synchronization signal block to be transmitted in a first time slot and a second sidelink synchronization signal block to be transmitted in a second time slot in a sidelink bandwidth portion of a shared spectrum; generating a physical broadcast channel (PBCH) repetition or cyclic prefix extension to fill a gap between the first sidelink synchronization signal block and the second sidelink synchronization signal block; and transmitting the first sidelink synchronization signal block in the first time slot and transmitting the second sidelink synchronization signal block in the second time slot together with a physical broadcast channel repetition or cyclic prefix extension between the first sidelink synchronization signal block and the second sidelink synchronization signal block.

[0056] A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to: identify a first side link synchronization signal block to be transmitted in a first time slot and a second side link synchronization signal block to be transmitted in a second time slot in a side link bandwidth portion of a shared spectrum; generate a physical broadcast channel (PBCH) repetition or cyclic prefix extension to fill a gap between the first side link synchronization signal block and the second side link synchronization signal block; and transmit the first side link synchronization signal block in the first time slot and transmit the second side link synchronization signal block in the second time slot together with a physical broadcast channel repetition or cyclic prefix extension between the first side link synchronization signal block and the second side link synchronization signal block.

[0057] In some examples of methods, apparatuses (devices), and non-transitory computer-readable media described herein, generating a physical broadcast channel repetition to fill the gap may include operations, features, means, or instructions for: generating a physical broadcast channel repetition by repeating the physical broadcast channel in the last symbol of the first side link synchronization signal block. In some examples of methods, apparatuses (devices), and non-transitory computer-readable media described herein, generating a cyclic prefix extension to fill the gap may include operations, features, means, or instructions for: generating a cyclic prefix extension based on the physical broadcast channel in the first symbol of the second side link synchronization signal block.

[0058] A method for wireless communication at a first UE is described. The method may include: performing a listen-before-talk procedure to obtain access to a sidelink bandwidth portion in a shared spectrum for a sidelink synchronization signal block period; transmitting one or more sidelink synchronization signal blocks using one or more beams in the sidelink synchronization signal block period, each of the one or more sidelink synchronization signal blocks being transmitted using a different beam; and receiving from a second UE an indication of a preferred beam of the one or more beams for transmitting sidelink data to the second UE based on transmitting the one or more sidelink synchronization signal blocks.

[0059] An apparatus for wireless communication at a first UE is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to: perform a listen-before-talk procedure to obtain access to a sidelink bandwidth portion in a shared spectrum for a sidelink synchronization signal block period; transmit one or more sidelink synchronization signal blocks using one or more beams in the sidelink synchronization signal block period, each of the one or more sidelink synchronization signal blocks being transmitted using a different beam; and receive from a second UE an indication of a preferred beam of the one or more beams for transmitting sidelink data to the second UE based on transmitting the one or more sidelink synchronization signal blocks.

[0060] Another apparatus for wireless communication at a first UE is described. The apparatus may include means for performing a listen-before-talk procedure to obtain access to a sidelink bandwidth portion in a shared spectrum for a sidelink synchronization signal block period; transmitting one or more sidelink synchronization signal blocks using one or more beams in the sidelink synchronization signal block period, each of the one or more sidelink synchronization signal blocks being transmitted using a different beam; and receiving, from a second UE, an indication of a preferred beam of the one or more beams for transmitting sidelink data to the second UE based on transmitting the one or more sidelink synchronization signal blocks.

[0061] A non-transitory computer-readable medium storing code for wireless communication at a first UE is described. The code may include instructions executable by a processor to perform the following operations: perform a listen-before-talk procedure to obtain access to a sidelink bandwidth portion in a shared spectrum for a sidelink synchronization signal block period; transmit one or more sidelink synchronization signal blocks using one or more beams in the sidelink synchronization signal block period, each of the one or more sidelink synchronization signal blocks being transmitted using a different beam; and receive from a second UE an indication of a preferred beam of the one or more beams for transmitting sidelink data to the second UE based on transmitting the one or more sidelink synchronization signal blocks.

[0062] Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include the following operations, features, devices, or instructions: using the preferred beam to transmit sidelink data to a second UE. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, receiving an indication of a preferred beam may include operations, features, devices, or instructions for the following actions: receiving signaling on a physical sidelink feedback channel (PFSCH) resource or a physical random access channel (PRACH) resource corresponding to a sidelink synchronization signal block transmitted using a preferred beam. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, an indication of a preferred beam may be received in a physical sidelink shared channel (PSSCH).

[0063] A method of wireless communication at a first UE is described. The method may include: receiving one or more sidelink synchronization signal blocks transmitted using one or more beams from a second UE in a sidelink synchronization signal block period, each of the one or more sidelink synchronization signal blocks being transmitted using a different beam; selecting a preferred beam of the one or more beams for the second UE to use to transmit sidelink data to the first UE; and transmitting an indication of the preferred beam to the second UE based on the selection.

[0064] An apparatus for wireless communication at a first UE is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions are executable by the processor to cause the apparatus to: receive one or more sidelink synchronization signal blocks transmitted using one or more beams from a second UE in a sidelink synchronization signal block period, each of the one or more sidelink synchronization signal blocks being transmitted using a different beam; select a preferred beam from the one or more beams for the second UE to use to transmit sidelink data to the first UE; and transmit an indication of the preferred beam to the second UE based on the selection.

[0065] Another apparatus for wireless communication at a first UE is described. The apparatus may include means for: receiving one or more sidelink synchronization signal blocks transmitted using one or more beams from a second UE in a sidelink synchronization signal block period, each of the one or more sidelink synchronization signal blocks being transmitted using a different beam; selecting a preferred beam of the one or more beams for the second UE to use to transmit sidelink data to the first UE; and transmitting an indication of the preferred beam to the second UE based on the selection.

[0066] A non-transitory computer-readable medium storing code for wireless communication at a first UE is described. The code may include instructions executable by a processor to: receive one or more sidelink synchronization signal blocks transmitted using one or more beams from a second UE in a sidelink synchronization signal block period, each of the one or more sidelink synchronization signal blocks being transmitted using a different beam; select a preferred beam of the one or more beams for the second UE to use to transmit sidelink data to the first UE; and transmit an indication of the preferred beam to the second UE based on the selection.

[0067] Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include the following operations, features, devices, or instructions: using the preferred beam to receive sidelink data from the second UE. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, transmitting an indication of the preferred beam may include operations, features, devices, or instructions for the following actions: transmitting signaling on a physical sidelink feedback channel (PFSCH) resource or a physical random access channel (PRACH) resource corresponding to a sidelink synchronization signal block transmitted by the second UE using the preferred beam. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the indication of the preferred beam may be received in a physical sidelink shared channel (PSSCH).

[0068] A method for wireless communication at a first UE is described. The method may include: performing a listen-before-talk procedure to obtain access to a sidelink bandwidth portion in a shared spectrum for a sidelink synchronization signal block period; determining whether a first number or a second number of sidelink synchronization signal blocks are to be transmitted in the sidelink synchronization signal block period, the first number being greater than the second number; and transmitting the first number or the second number of sidelink synchronization signal blocks in the sidelink synchronization signal block period based on the determination.

[0069] An apparatus for wireless communication at a first UE is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to: perform a listen-before-talk procedure to obtain access to a sidelink bandwidth portion in a shared spectrum for a sidelink synchronization signal block period; determine whether a first number or a second number of sidelink synchronization signal blocks are to be transmitted in the sidelink synchronization signal block period, the first number being greater than the second number; and transmit the first number or the second number of sidelink synchronization signal blocks in the sidelink synchronization signal block period based on the determination.

[0070] Another apparatus for wireless communication at a first UE is described. The apparatus may include means for performing a listen-before-talk procedure to obtain access to a sidelink bandwidth portion in a shared spectrum for a sidelink synchronization signal block period; determining whether a first number or a second number of sidelink synchronization signal blocks are to be transmitted in the sidelink synchronization signal block period, the first number being greater than the second number; and transmitting the first number or the second number of sidelink synchronization signal blocks in the sidelink synchronization signal block period based on the determination.

[0071] A non-transitory computer-readable medium storing code for wireless communication at a first UE is described. The code may include instructions executable by a processor to perform the following operations: perform a listen-before-talk procedure to obtain access to a sidelink bandwidth portion in a shared spectrum for a sidelink synchronization signal block period; determine whether to transmit a first number or a second number of sidelink synchronization signal blocks in the sidelink synchronization signal block period, the first number being greater than the second number; and transmit the first number or the second number of sidelink synchronization signal blocks in the sidelink synchronization signal block period based on the determination.

[0072] Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for the following actions: receiving an indication from a second UE that a first number of sidelink synchronization signal blocks are to be transmitted in a sidelink synchronization signal block period. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, transmitting the first number or the second number of sidelink synchronization signal blocks may include operations, features, means, or instructions for the following actions: transmitting the first number of sidelink synchronization signal blocks using one or more beams as part of a beam improvement procedure based on receiving the indication, each of the first number of sidelink synchronization signal blocks being transmitted using a different beam.

[0073] In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, transmitting the first number or the second number of sidelink synchronization signal blocks may include operations, features, means, or instructions for the following actions: transmitting the first number of sidelink synchronization signal blocks after a preconfigured time period after receiving an indication that the first number of sidelink synchronization signal blocks are to be transmitted. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the indication that the first number of sidelink synchronization signal blocks are to be transmitted may be received in a physical random access channel (PRACH), sidelink control information, or a media access control (MAC) control element (MAC-CE).

[0074] In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, determining whether to transmit a first number or a second number of sidelink synchronization signal blocks may include operations, features, devices, or instructions for the following actions: determining to transmit a second number of sidelink synchronization signal blocks based on a failure to receive an indication that a first number of sidelink synchronization signal blocks are to be transmitted in a sidelink synchronization signal block period. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, transmitting a first number or a second number of sidelink synchronization signal blocks may include operations, features, devices, or instructions for the following actions: transmitting a second number of sidelink synchronization signal blocks using a first beam set; and transmitting a first number of sidelink synchronization signal blocks using a second beam set associated with a beam improvement procedure for one or more beams in the first beam set.

[0075] A method for wireless communication at a first UE is described. The method may include: determining whether to receive a first number or a second number of sidelink synchronization signal blocks from a second UE in a sidelink synchronization signal block period, the first number being greater than the second number; identifying a sidelink synchronization signal block period having the first number or the second number of sidelink synchronization signal blocks; and receiving the first number or the second number of sidelink synchronization signal blocks in the sidelink synchronization signal block period based on the determination.

[0076] An apparatus for wireless communication at a first UE is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to: determine whether to receive a first number or a second number of sidelink synchronization signal blocks from a second UE in a sidelink synchronization signal block period, the first number being greater than the second number; identify a sidelink synchronization signal block period having the first number or the second number of sidelink synchronization signal blocks; and receive the first number or the second number of sidelink synchronization signal blocks in the sidelink synchronization signal block period based on the determination.

[0077] Another apparatus for wireless communication at a first UE is described. The apparatus may include means for determining whether a first number or a second number of sidelink synchronization signal blocks are to be received from a second UE in a sidelink synchronization signal block period, the first number being greater than the second number; identifying a sidelink synchronization signal block period having the first number or the second number of sidelink synchronization signal blocks; and receiving the first number or the second number of sidelink synchronization signal blocks in the sidelink synchronization signal block period based on the determination.

[0078] A non-transitory computer-readable medium storing code for wireless communication at a first UE is described. The code may include instructions executable by a processor to: determine whether to receive a first number or a second number of sidelink synchronization signal blocks from a second UE in a sidelink synchronization signal block period, the first number being greater than the second number; identify a sidelink synchronization signal block period having the first number or the second number of sidelink synchronization signal blocks; and receive the first number or the second number of sidelink synchronization signal blocks in the sidelink synchronization signal block period based on the determination.

[0079] Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for the following actions: transmitting to the second UE an indication that the second UE is to transmit a first number of sidelink synchronization signal blocks in a sidelink synchronization signal block period. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, receiving the first number or the second number of sidelink synchronization signal blocks may include operations, features, means, or instructions for the following actions: based on transmitting the indication, receiving a first number of sidelink synchronization signal blocks transmitted using one or more beams as part of a beam improvement procedure, each of the first number of sidelink synchronization signal blocks being transmitted using a different beam.

[0080] In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, receiving the first number or the second number of sidelink synchronization signal blocks may include operations, features, means, or instructions for the following actions: receiving the first number of sidelink synchronization signal blocks after a preconfigured time period after transmitting an indication to the second UE that the first number of sidelink synchronization signal blocks are to be transmitted. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the indication that the first number of sidelink synchronization signal blocks are to be transmitted may be transmitted in a physical random access channel (PRACH), sidelink control information, or a media access control (MAC) control element (MAC-CE).

[0081] In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, receiving a first number or a second number of sidelink synchronization signal blocks may include operations, features, means, or instructions for the following actions: receiving a second number of sidelink synchronization signal blocks based on a failure to transmit an indication that the second UE is to transmit a first number of sidelink synchronization signal blocks in a sidelink synchronization signal block period. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, receiving a first number or a second number of sidelink synchronization signal blocks may include operations, features, means, or instructions for the following actions: receiving a second number of sidelink synchronization signal blocks transmitted using a first beam set; and receiving a first number of sidelink synchronization signal blocks transmitted using a second beam set associated with a beam improvement procedure for one or more beams in the first beam set. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] Figure 1

[0013] Illustrated are aspects of a wireless communication system supporting sidelink synchronization signal block (S-SSB) transmission in a shared spectrum in accordance with aspects of the present disclosure.

[0084] Figure 2

[0013] Various aspects of a wireless communication system supporting S-SSB transmissions in a shared spectrum in accordance with various aspects of the present disclosure are illustrated.

[0085] Figure 3 Various aspects of the location of synchronization signal block (SSB) transmissions in accordance with various aspects of the present disclosure are illustrated.

[0086] Figure 4 Various aspects of the location of SSB transmissions in accordance with various aspects of the present disclosure are illustrated.

[0087] Figure 5 Various aspects of SSB transmission in beam sweeping according to various aspects of the present disclosure are illustrated.

[0088] Figure 6 Various aspects of SSB transmission in beam sweeping according to various aspects of the present disclosure are illustrated.

[0089] Figure 7 Various aspects of SSB transmission in a DRS window according to various aspects of the present disclosure are illustrated.

[0090] Figure 8 Various aspects of SSB transmission across multiple time slots are illustrated in accordance with various aspects of the present disclosure.

[0091] Fig. 9 Various aspects of on-demand S-SSB sweeping according to various aspects of the present disclosure are explained.

[0092] Fig.10Various aspects of on-demand S-SSB sweeping including multiple S-SSB burst transmissions in a single S-SSB period are illustrated in accordance with various aspects of the present disclosure.

[0093] Fig.11 and 12 A block diagram of a device supporting S-SSB transmission in a shared spectrum according to aspects of the present disclosure is shown.

[0094] Fig.13 A block diagram of a communication manager supporting S-SSB transmissions in a shared spectrum is shown in accordance with aspects of the present disclosure.

[0095] Fig.14 A diagram of a system including devices supporting S-SSB transmissions in a shared spectrum is shown in accordance with aspects of the present disclosure.

[0096] Figures 15 to 28 A flow chart illustrating a method of supporting S-SSB transmissions in a shared spectrum according to aspects of the present disclosure is shown.

[0097] Detailed Description

[0098] Some wireless communication systems may support sidelink communications between user equipment (UE) in a shared spectrum. In such a system, the UE may perform a listen-before-talk (LBT) procedure to obtain access to a sidelink bandwidth part (BWP) for sidelink transmission. For example, the UE may obtain access to the sidelink BWP to transmit a sidelink synchronization signal block (S-SSB). The S-SSB may allow other UEs to discover the UE and establish a sidelink connection with the UE for subsequent sidelink communications. However, in some cases, because the UE may contend for access to resources in the shared spectrum for transmitting the S-SSB, it may be challenging for other UEs to identify the resources on which the S-SSB is transmitted. In addition, because the sidelink resources in the shared spectrum may be limited, and many UEs may be competing for access to the limited sidelink resources, unnecessary overhead and other inefficiencies may be harmful to the sidelink communications in the shared spectrum.

[0099] As described herein, a UE may support efficient techniques for facilitating S-SSB transmission in a shared spectrum. Specifically, the UE may efficiently identify resources for transmitting one or more S-SSBs in a shared spectrum or efficiently beam sweep multiple S-SSBs in a shared spectrum. In one aspect, the UE may transmit an S-SSB in a sidelink BWP in a shared spectrum so that the lower edge of the S-SSB is aligned with or offset from the lower edge of the sidelink BWP. On the other hand, the UE may beam sweep the S-SSBs in one or more S-SSB bursts in an S-SSB period to increase the chance that another UE may receive the S-SSB. On yet another aspect, resources allocated for S-SSB transmission may facilitate flexible S-SSB transmission while minimizing gaps to prevent other UEs from erroneously determining that the sidelink BWP in the shared spectrum is unobstructed for transmission. By using these techniques, the UE may avoid unnecessary overhead when transmitting an S-SSB while allowing the receiving UE to identify the S-SSB transmitted by the UE.

[0100] The various aspects of the present disclosure introduced above are described below in the context of a wireless communication system. Examples of processes and signaling exchanges supporting S-SSB transmission in a shared spectrum are subsequently described. Various aspects of the present disclosure are further illustrated and described by and with reference to apparatus diagrams, system diagrams, and flow charts related to S-SSB transmission in a shared spectrum.

[0101] Figure 1 An example of a wireless communication system 100 supporting S-SSB transmission in a shared spectrum according to various aspects of the present disclosure is illustrated. The wireless communication system 100 may include one or more base stations 105, one or more UEs 115, and a core network 130. In some examples, the wireless communication system 100 may be a long term evolution (LTE) network, an advanced LTE (LTE-A) network, an LTE-A Pro network, or a new radio (NR) network. In some examples, the wireless communication system 100 may support enhanced broadband communications, ultra-reliable (e.g., mission-critical) communications, low latency communications, communications with low-cost and low-complexity devices, or any combination thereof.

[0102] The base stations 105 may be dispersed throughout a geographic area to form the wireless communication system 100, and may be different forms of devices or devices with different capabilities. The base stations 105 and the UEs 115 may communicate wirelessly via one or more communication links 125. Each base station 105 may provide a coverage area 110 over which the UEs 115 and the base stations 105 may establish one or more communication links 125. The coverage area 110 may be an example of a geographic area over which the base stations 105 and the UEs 115 may support communication of signals according to one or more radio access technologies.

[0103] The UEs 115 may be dispersed throughout the coverage area 110 of the wireless communication system 100, and each UE 115 may be stationary or mobile, or stationary and mobile at different times. The UEs 115 may be different forms of devices or devices with different capabilities. Figure 1 Some example UEs 115 are illustrated in FIG. 1. The UEs 115 described herein may be capable of communicating with various types of devices, such as other UEs 115, base stations 105, or network equipment (e.g., core network nodes, relay devices, integrated access and backhaul (IAB) nodes, or other network equipment), such as Figure 1 as shown in .

[0104] Each base station 105 may communicate with the core network 130, or communicate with each other, or both. For example, the base station 105 may interface with the core network 130 via one or more backhaul links 120 (e.g., via S1, N2, N3 or other interfaces). The base stations 105 may communicate with each other directly (e.g., directly between the base stations 105), or indirectly (e.g., via the core network 130), or directly and indirectly on the backhaul link 120 (e.g., via X2, Xn or other interfaces). In some aspects, the backhaul link 120 may be or include one or more wireless links.

[0105] One or more of the base stations 105 described herein may include or may be referred to by a person of ordinary skill in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a B node, an evolved B node (eNB), a next generation B node or a gigabit B node (any of which may be referred to as a gNB), a home B node, a home evolved B node, or other suitable terminology.

[0106] UE 115 may include or may be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable term, where a "device" may also be referred to as a unit, a station, a terminal, or a client, etc. UE 115 may also include or may be referred to as a personal electronic device, such as a cellular phone, a personal digital assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some aspects, UE 115 may include or be referred to as a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a machine type communication (MTC) device, etc., which may be implemented in various objects such as appliances or vehicles, meters, etc.

[0107] The UE 115 described herein may be able to communicate with various types of devices, such as other UEs 115, which may sometimes act as relays, as well as base stations 105 and network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, relay base stations, etc. Figure 1 as shown in .

[0108] The UE 115 and the base station 105 may communicate wirelessly with each other via one or more communication links 125 on one or more carriers. The term "carrier" may refer to a set of radio frequency spectrum resources having a defined physical layer structure for supporting the communication link 125. For example, a carrier for the communication link 125 may include a portion of a radio frequency spectrum band (e.g., a bandwidth portion (BWP)) that operates according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information), control signaling for coordinating carrier operations, user data, or other signaling. The wireless communication system 100 may support communication with the UE 115 using carrier aggregation or multi-carrier operation. The UE 115 may be configured to have multiple downlink component carriers and one or more uplink component carriers according to a carrier aggregation configuration. Carrier aggregation may be used in conjunction with both frequency division duplex (FDD) and time division duplex (TDD) component carriers.

[0109] In some aspects (e.g., in a carrier aggregation configuration), a carrier may also have acquisition signaling or control signaling that coordinates the operation of other carriers. A carrier may be associated with a frequency channel (e.g., an Evolved Universal Mobile Telecommunications System Terrestrial Radio Access (E-UTRA) Absolute Radio Frequency Channel Number (EARFCN)) and may be located according to a channel grid for discovery by a UE 115. A carrier may operate in a standalone mode in which initial acquisition and connection may be made by a UE 115 via the carrier, or a carrier may operate in a non-standalone mode in which a connection is anchored using a different carrier (e.g., a different carrier of the same or different radio access technology).

[0110] The communication link 125 shown in the wireless communication system 100 may include an uplink transmission from the UE 115 to the base station 105 (e.g., in a physical uplink shared channel (PUSCH) or a physical uplink control channel (PUCCH)) or a downlink transmission from the base station 105 to the UE 115 (e.g., in a physical downlink shared channel (PDSCH) or a physical downlink control channel (PDCCH)). A carrier may carry downlink or uplink communications (e.g., in FDD mode) or may be configured to carry both downlink and uplink communications (e.g., in TDD mode).

[0111] A carrier may be associated with a particular bandwidth of a radio frequency spectrum, and in some aspects, the carrier bandwidth may be referred to as a "system bandwidth" of the carrier or wireless communication system 100. For example, the carrier bandwidth may be one of several determined bandwidths (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 megahertz (MHz)) of a carrier of a particular radio access technology. Devices (e.g., base stations 105, UEs 115, or both) of the wireless communication system 100 may have a hardware configuration that supports communications on a particular carrier bandwidth, or may be configurable to support communications on one of a set of carrier bandwidths. In some aspects, the wireless communication system 100 may include a base station 105 or UE 115 that supports simultaneous communications via carriers associated with multiple carrier bandwidths. In some aspects, each served UE 115 may be configured to operate on a portion (e.g., subband, BWP) or all of a carrier bandwidth.

[0112] The signal waveform transmitted on the carrier may include multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques, such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)). In a system using MCM technology, a resource element may include a code element period (e.g., the duration of a modulation code element) and a subcarrier, where the code element period and the subcarrier spacing are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the code rate of the modulation scheme, or both). Thus, the more resource elements received by UE 115 and the higher the order of the modulation scheme, the higher the data rate of UE 115 can be. Wireless communication resources may refer to a combination of radio frequency spectrum resources, time resources, and spatial resources (e.g., spatial layers or beams), and the use of multiple spatial layers can further improve the data rate or data integrity of communication with UE 115.

[0113] One or more parameter designs for a carrier may be supported, where the parameter designs may include subcarrier spacing (Δf) and cyclic prefixes. A carrier may be divided into one or more BWPs with the same or different parameter designs. In some aspects, a UE 115 may be configured with multiple BWPs. In some aspects, a single BWP for a carrier may be active at a given time, and communications for a UE 115 may be limited to the one or more active BWPs.

[0114] The time interval of the base station 105 or the UE 115 can be expressed as a multiple of a basic time unit, and the basic time unit can be, for example, a sampling period T s =1 / (Δf max ·Nf) seconds, where Δf maxNf may represent the maximum supported subcarrier spacing, and Nf may represent the maximum supported discrete Fourier transform (DFT) size. Time intervals of communication resources may be organized according to radio frames, each having a specified duration (e.g., 10 milliseconds (ms)). Each radio frame may be identified by a system frame number (SFN) (e.g., ranging from 0 to 1023).

[0115] Each frame may include a plurality of consecutively numbered subframes or time slots, and each subframe or time slot may have the same duration. In some aspects, a frame may be divided into subframes (e.g., in the time domain), and each subframe may be further divided into a number of time slots. Alternatively, each frame may include a variable number of time slots, and the number of time slots may depend on the subcarrier spacing. Each time slot may include a number of code element periods (e.g., depending on the length of the cyclic prefix added before each code element period). In some wireless communication systems 100, the time slot may be further divided into a plurality of mini-time slots containing one or more code elements. Excluding the cyclic prefix, each code element period may include one or more (e.g., Nf) sampling periods. The duration of the code element period may depend on the subcarrier spacing or the operating frequency band.

[0116] A subframe, slot, mini-slot, or symbol may be the smallest scheduling unit (e.g., in the time domain) of the wireless communication system 100 and may be referred to as a transmission time interval (TTI). In some aspects, the TTI duration (e.g., the number of symbol periods in a TTI) may be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communication system 100 may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs)).

[0117] Physical channels may be multiplexed on a carrier according to various techniques. Physical control channels and physical data channels may be multiplexed on a downlink carrier, for example, using one or more of a time division multiplexing (TDM) technique, a frequency division multiplexing (FDM) technique, or a hybrid TDM-FDM technique. A control region (e.g., a control resource set (CORESET)) for a physical control channel may be defined by a number of symbol periods and may extend across a system bandwidth or a subset of a system bandwidth of a carrier. One or more control regions (e.g., CORESETs) may be configured for a set of UEs 115. For example, one or more of the UEs 115 may monitor or search a control region for control information according to one or more search space sets, and each search space set may include one or more control channel candidates in one or more aggregation levels arranged in a cascaded manner. An aggregation level for a control channel candidate may refer to the number of control channel resources (e.g., control channel elements (CCEs)) associated with coded information for a control information format having a given payload size. The search space sets may include a common search space set configured for transmitting control information to multiple UEs 115 and a UE-specific search space set for transmitting control information to a specific UE 115 .

[0118] In some aspects, the base stations 105 can be mobile and thus provide communication coverage for mobile geographic coverage areas 110. In some aspects, different geographic coverage areas 110 associated with different technologies can overlap, but the different geographic coverage areas 110 can be supported by the same base station 105. In other aspects, overlapping geographic coverage areas 110 associated with different technologies can be supported by different base stations 105. The wireless communication system 100 can include, for example, a heterogeneous network in which different types of base stations 105 provide coverage for various geographic coverage areas 110 using the same or different radio access technologies.

[0119] The wireless communication system 100 may be configured to support ultra-reliable communication or low latency communication or various combinations thereof. For example, the wireless communication system 100 may be configured to support ultra-reliable low latency communication (URLLC) or mission-critical communication. UE 115 may be designed to support ultra-reliable, low latency or critical functions (e.g., mission-critical functions). Ultra-reliable communication may include private communication or group communication, and may be supported by one or more mission-critical services (such as mission-critical push-to-talk (MCPTT), mission-critical video (MCVideo), or mission-critical data (MCData). Support for mission-critical functions may include prioritization of services, and mission-critical services may be used for public safety or general commercial applications. The terms ultra-reliable, low latency, critical mission, and ultra-reliable low latency may be used interchangeably herein.

[0120] In some aspects, UE 115 may also be able to communicate directly with other UE 115 on a device-to-device (D2D) communication link 135 (e.g., using a peer-to-peer (P2P) or D2D protocol). One or more UE 115 utilizing D2D communication may be within a geographic coverage area 110 of a base station 105. Other UE 115 in such a group may be outside the geographic coverage area 110 of a base station 105, or may not be able to receive transmissions from a base station 105 for other reasons. In some aspects, a group of UEs 115 communicating via D2D communication may utilize a one-to-many (1:M) system, wherein each UE 115 transmits to each other UE 115 in the group. In some aspects, a base station 105 facilitates the scheduling of resources for D2D communication. In other cases, D2D communication is performed between UEs 115 without involving a base station 105.

[0121] The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 may be an evolved packet core (EPC) or a 5G core (5GC), and the EPC or 5GC may include at least one control plane entity (e.g., a mobility management entity (MME), an access and mobility management function (AMF)) for managing access and mobility, and at least one user plane entity (e.g., a serving gateway (S-GW), a packet data network (PDN) gateway (P-GW), or a user plane function (UPF)) for routing packets or interconnecting to an external network. The control plane entity may manage non-access stratum (NAS) functions, such as mobility, authentication, and bearer management of UE 115 served by a base station 105 associated with the core network 130. User IP packets may be delivered via a user plane entity, which may provide IP address allocation and other functions. The user plane entity may be connected to a network operator IP service 150. Operator IP services 150 may include access to the Internet, an intranet, an IP Multimedia Subsystem (IMS), or packet-switched streaming services.

[0122] Some network devices (such as base stations 105) may include subcomponents, such as access network entities 140, which may be examples of access node controllers (ANCs). Each access network entity 140 may communicate with each UE 115 through one or more other access network transport entities 145, which may be referred to as radio heads, smart radio heads, or transmission / reception points (TRPs). Each access network transport entity 145 may include one or more antenna panels. In some configurations, the various functions of each access network entity 140 or base station 105 may be distributed across various network devices (e.g., radio heads and ANCs) or merged into a single network device (e.g., base station 105).

[0123] The wireless communication system 100 may operate using one or more frequency bands, typically in the range of 300 megahertz (MHz) to 300 gigahertz (GHz). In general, the 300 MHz to 3 GHz region is referred to as the ultra-high frequency (UHF) region or decimeter band because the wavelengths range from about 1 decimeter to 1 meter long. UHF waves may be blocked or redirected by buildings and environmental features, but these waves may penetrate various structures sufficiently for macro cells to provide service to UEs 115 located indoors. Transmissions using UHF waves may be associated with smaller antennas and shorter ranges (e.g., less than 100 kilometers) than transmissions using smaller frequencies and longer waves in the high frequency (HF) or very high frequency (VHF) portions of the spectrum below 300 MHz.

[0124] The wireless communication system 100 may also operate in a super high frequency (SHF) zone using a frequency band from 3 GHz to 30 GHz (also known as a centimeter band) or in an extremely high frequency (EHF) zone of a spectrum (e.g., from 30 GHz to 300 GHz) (also known as a millimeter band). In some aspects, the wireless communication system 100 may support millimeter wave (mmW) communications between UE 115 and base station 105, and the EHF antenna of the corresponding device may be smaller and more closely spaced than the UHF antenna. In some aspects, this may facilitate the use of antenna arrays within the device. However, the propagation of EHF transmissions may be subject to even greater atmospheric attenuation and a shorter range than SHF or UHF transmissions. The technology disclosed herein may be adopted across transmissions using one or more different frequency zones, and the use of frequency bands specified across these frequency zones may differ by country or regulatory agency.

[0125] In some cases, the wireless communication system 100 may utilize both non-shared (e.g., licensed) and shared (e.g., unlicensed) radio frequency spectrum bands. According to some aspects, the wireless communication system 100 may employ license assisted access (LAA), LTE unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed band (NR-U) (such as a 5GHz ISM band). When operating in an unlicensed radio frequency spectrum band, a wireless device (such as a base station 105 and a UE 115) may employ an LBT procedure to ensure that a frequency channel (e.g., an LBT subchannel or band accessible via an LBT procedure) is clear before transmitting data. In some cases, operations in an unlicensed band may be based on a carrier aggregation configuration (e.g., LAA) in coordination with component carriers operating in a licensed band. Operations in an unlicensed spectrum may include downlink transmissions, uplink transmissions, sidelink transmissions, peer-to-peer transmissions, or a combination of these. Duplexing in an unlicensed spectrum may be based on frequency division duplexing (FDD), time division duplexing (TDD), or a combination of the two.

[0126] In some implementations, there may be different categories of LBT procedures, including Category 1 LBT (i.e., no LBT), Category 2 LBT (i.e., LBT without a backoff period including one-time channel sensing for a fixed period), Category 3 LBT (i.e., LBT with a random (or other) backoff period and a fixed-size contention window), and Category 4 LBT (i.e., LBT with a random (or other) backoff period and a variable-size contention window). In some cases, the Category 2 LBT procedure may be referred to as a one-time LBT procedure, in which the UE 115 may perform channel sensing for a defined duration (e.g., 25 μs). In addition, the Category 4 LBT procedure may be referred to as a fairness-based LBT procedure for performing channel sensing with backoff, in which the backoff may be used to prevent the UE 115 from accessing the channel immediately after detecting that the channel is clear.

[0127] The base station 105 or UE 115 may be equipped with multiple antennas, which can be used to employ technologies such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. The antennas of the base station 105 or UE 115 may be located in one or more antenna arrays or antenna panels that can support MIMO operations or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly (such as an antenna tower). In some aspects, the antennas or antenna arrays associated with the base station 105 may be located at different geographical locations. The base station 105 may have an antenna array having antenna ports of several rows and columns that the base station 105 can use to support beamforming for communications with the UE 115. Similarly, the UE 115 may have one or more antenna arrays that can support various MIMO or beamforming operations. Additionally or alternatively, the antenna panel may support radio frequency beamforming for signals transmitted via the antenna ports.

[0128] The base station 105 or UE 115 can use MIMO communication to utilize multipath signal propagation and improve spectral efficiency by transmitting or receiving multiple signals via different spatial layers. Such technology may be referred to as spatial multiplexing. For example, the transmitting device may transmit multiple signals via different antennas or different antenna combinations. Similarly, the receiving device may receive multiple signals via different antennas or different antenna combinations. Each of the multiple signals may be referred to as a separate spatial stream and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams (e.g., different codewords). Different spatial layers may be associated with different antenna ports for channel measurement and reporting. MIMO technology includes single-user MIMO (SU-MIMO), in which multiple spatial layers are transmitted to the same receiving device; and multi-user MIMO (MU-MIMO), in which multiple spatial layers are transmitted to multiple devices.

[0129] Beamforming (which may also be referred to as spatial filtering, directional transmission, or directional reception) is a signal processing technique that may be used at a transmitting device or a receiving device (e.g., a base station 105, a UE 115) to shape or steer an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by combining signals communicated via antenna elements of an antenna array so that some signals propagating at a particular orientation relative to the antenna array experience constructive interference, while other signals experience destructive interference. Adjustments to signals communicated via antenna elements may include the transmitting device or the receiving device applying an amplitude offset, a phase offset, or both to signals carried via antenna elements associated with the device. Adjustments associated with each antenna element may be defined by a set of beamforming weights associated with a particular orientation (e.g., relative to the antenna array of the transmitting device or the receiving device, or relative to some other orientation).

[0130] The base station 105 or the UE 115 may use beam sweeping techniques as part of a beamforming operation. For example, the base station 105 may use multiple antennas or antenna arrays (e.g., antenna panels) to perform beamforming operations for directional communication with the UE 115. Some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted multiple times by the base station 105 in different directions. For example, the base station 105 may transmit signals according to different sets of beamforming weights associated with different transmission directions. Transmissions in different beam directions may be used (e.g., by a transmitting device (such as the base station 105) or a receiving device (such as the UE 115)) to identify a beam direction used by the base station 105 for later transmission or reception.

[0131] Some signals, such as data signals associated with a particular recipient device, may be transmitted by base station 105 in a single beam direction, e.g., a direction associated with a recipient device, such as UE 115. In some aspects, a beam direction associated with transmissions along a single beam direction may be determined based on signals transmitted in one or more beam directions. For example, UE 115 may receive one or more signals transmitted by base station 105 in different directions and may report to base station 105 an indication of the signal received by UE 115 with the highest signal quality or other acceptable signal quality.

[0132] In some aspects, transmission by a device (e.g., by a base station 105 or a UE 115) may be performed using multiple beam directions, and the device may use a combination of digital precoding or radio frequency beamforming to generate a combined beam for transmission (e.g., from the base station 105 to the UE 115). The UE 115 may report feedback indicating precoding weights for one or more beam directions, and the feedback may correspond to a configured number of beams across the system bandwidth or one or more subbands. The base station 105 may transmit reference signals (e.g., cell-specific reference signals (CRS), channel state information reference signals (CSI-RS)) that may be precoded or unprecoded. The UE 115 may provide feedback for beam selection, which may be a precoding matrix indicator (PMI) or codebook-based feedback (e.g., a multi-panel type codebook, a linear combination type codebook, a port selection type codebook). Although these techniques are described with reference to signals transmitted by base station 105 in one or more directions, UE 115 may use similar techniques to transmit signals multiple times in different directions (e.g., to identify a beam direction for subsequent transmission or reception by UE 115) or to transmit signals in a single direction (e.g., to transmit data to a receiving device).

[0133] A receiving device (e.g., UE 115) may try multiple reception configurations (e.g., directional listening) when receiving various signals (such as synchronization signals, reference signals, beam selection signals, or other control signals) from a base station 105. For example, the receiving device may try multiple reception directions by receiving via different antenna subarrays, processing received signals according to different antenna subarrays, receiving according to different receive beamforming weight sets (e.g., different directional listening weight sets) applied to signals received at multiple antenna elements of an antenna array, or processing received signals according to different receive beamforming weight sets applied to signals received at multiple antenna elements of an antenna array, any of which may be referred to as "listening" according to different reception configurations or reception directions. In some aspects, a receiving device may use a single reception configuration to receive along a single beam direction (e.g., when receiving a data signal). The single reception configuration may be aligned on a beam direction determined based on listening according to different reception configuration directions (e.g., a beam direction determined to have the highest signal strength, the highest signal-to-noise ratio (SNR), or other acceptable signal quality based on listening according to multiple beam directions).

[0134] The wireless communication system 100 may be a packet-based network that operates according to a layered protocol stack. In the user plane, the communication of the bearer or packet data convergence protocol (PDCP) layer may be IP-based. The radio link control (RLC) layer may perform packet segmentation and reassembly to communicate on a logical channel. The media access control (MAC) layer may perform priority handling and multiplex logical channels into transport channels. The MAC layer may also use error detection techniques, error correction techniques, or both to support retransmission of the MAC layer to improve link efficiency. In the control plane, the radio resource control (RRC) protocol layer may provide the establishment, configuration, and maintenance of an RRC connection that supports radio bearers of user plane data between UE 115 and base station 105 or core network 130. In the physical layer, transport channels may be mapped to physical channels.

[0135] A UE 115 in the wireless communication system 100 may be able to communicate directly with other UEs 115 on a sidelink connection (e.g., using a peer-to-peer (P2P) or device-to-device (D2D) protocol). Such communication may be referred to as D2D communication or sidelink communication. One or more UEs in a group of UEs 115 utilizing sidelink communication may be within a geographic coverage area 110 of a base station 105. In some cases, other UEs 115 in the group may be outside the geographic coverage area 110 of the base station 105, or may not be able to receive transmissions from the base station 105 for other reasons. In such a case, a UE 115 within the geographic coverage 110 of the base station 105 may relay communications between the base station 105 and a UE 115 outside the geographic area 110 of the base station 105. UEs 115 communicating via sidelink communication may utilize a one-to-many (1:M) system, in which each UE 115 transmits to each other UE 115 in the group.

[0136] In some cases, a UE 115 in a wireless communication system 100 may support sidelink communications in a shared spectrum. In such a system, a UE 115 may perform an LBT procedure to obtain access to a sidelink BWP for sidelink transmission. For example, a UE 115 may obtain access to a sidelink BWP to transmit an S-SSB in a physical sidelink broadcast channel (PSBCH). An S-SSB may allow other UEs 115 to discover the UE 115 and establish a sidelink connection with the UE 115 for subsequent sidelink communications. An S-SSB may be 11 resource blocks wide, and a UE 115 may transmit an S-SSB using the same parameter design as the sidelink BWP in which the S-SSB is transmitted. In some cases, an S-SSB may not meet the occupied channel bandwidth (OCB) requirement of a channel (e.g., at 5 GHz). In such a situation, UE 115 may transmit S-SSB in a discovery reference signal (DRS) window (e.g., NR-U DRS window) together with the remaining minimum system information (RMSI), channel state information reference signal (CSI-RS), etc. in the PDSCH. That is, RMSI, CSI-RS, etc. may be frequency-division multiplexed with the S-SSB to meet the OCB requirements of the channel. Additionally or alternatively, the S-SSB may be repeated in the frequency domain (e.g., to meet the OCB requirements). Table 1 below shows the contents of the PBSCH.

[0137] Table 1: PBSCH content and associated bit numbers

[0138] PBSCH content Number of bits Direct Frame Number (DFN) 10 Indications for TDD configuration

[12] Time slot index 7 Overlay indicator 1 Reserved bits 2 Cyclic Redundancy Check (CRC) 24 Total Bits 56

[0139] As described above, a UE 115 in a wireless communication system 100 may transmit an S-SSB in a shared spectrum. However, in some cases, because the UE 115 may contend for access to resources in the shared spectrum for transmitting the S-SSB, it may be challenging for other UEs to identify the resources on which the S-SSB is transmitted. In addition, because the sidelink resources in the shared spectrum may be limited, and many UEs 115 may be competing for access to the limited sidelink resources, unnecessary overhead and other inefficiencies may be harmful to sidelink communications in the shared spectrum. In such a situation, selecting a position for the S-SSB in the sidelink BWP in the shared spectrum may facilitate other UEs 115 to receive the S-SSB. That is, it may be beneficial to define the position of the S-SSB in the sidelink BWP in the NR-U channel according to the described characteristics. In addition, it may be beneficial to efficiently configure the DRS window for S-SSB transmission in the shared spectrum (for example, this is because in NR-U, the UE 115 may perform channel access before the S-SSB transmission). The wireless communication system 100 may support efficient techniques for facilitating S-SSB transmissions in a shared spectrum.

[0140] Figure 2 Various aspects of a wireless communication system 200 supporting S-SSB transmission in a shared spectrum according to various aspects of the present disclosure are illustrated. The wireless communication system 200 includes a base station 105-a, which may be a reference Figure 1 The wireless communication system 200 also includes UE 115-a and UE 115-b, which may be referenced Figure 1 An example of a UE 115 is described. A base station 105-a may provide communication coverage for a geographic coverage area 110-a, which may be a reference Figure 1 An example of a geographic area 110 is described. Base station 105-a can communicate with UE 115-a and UE 115-b on resources of carrier 205, and UE 115-a can communicate with UE 115-b on resources of carrier 210. Communications between UE 115-a and UE 115-b may be referred to as sidelink communications. In some cases, base station 105-a may schedule resources for communications between UE 115-a and UE 115-b (e.g., in resource allocation mode 1). In other cases, UE 115-a or UE 115-b may identify resources for communicating with each other without the involvement of base station 105-a (e.g., in resource allocation mode 2).

[0141] The wireless communication system 200 may implement aspects of the wireless communication system 100. For example, the wireless communication system 200 may support efficient techniques for facilitating S-SSB transmissions in a shared spectrum. Using the techniques described herein, the UE 115-a may efficiently identify resources for transmitting one or more S-SSBs in a shared spectrum or efficiently beam sweep multiple S-SSBs in a shared spectrum. The UE 115-b may then receive one or more S-SSBs. In one aspect, the UE 115-a may transmit the S-SSB in a sidelink BWP in the shared spectrum so that the lower edge of the S-SSB is aligned with or offset from the lower edge of the sidelink BWP. On the other hand, the UE 115-a may beam sweep the S-SSBs in one or more S-SSB bursts in an S-SSB period to increase the chance that the UE 115-b may receive the S-SSB. On the other hand, the resources allocated for S-SSB transmission can facilitate flexible S-SSB transmission while minimizing gaps to prevent other UEs 115 from erroneously determining that the sidelink BWP in the shared spectrum is clear for transmission.

[0142] Figure 3 Illustrated are aspects of the location 300 of SSB transmissions in accordance with aspects of the present disclosure. The base station 105 may identify a BWP 305 in a shared spectrum and may transmit an SSB 315-a and an SSB 315-b in the BWP 305. The UE 115 may identify a sidelink BWP 310 in the shared spectrum and the UE 115 may transmit an S-SSB 320 in the sidelink BWP 310. The BWP 305 and the sidelink BWP 310 may span the same set of frequency resources. The SSB 315-a and the SSB 315-b may span 20 resource blocks and may be aligned with the lower edge of the BWP 305 (i.e., in NR-U, a 20RB SSB may be located at the lower edge of a 20MHz channel). The center frequency for NR SSB reception may be at the 0th subcarrier in the 10th resource block. Figure 3305. In the embodiment of the present invention, the S-SSB 320 may span 11 resource blocks and may be offset from the lower edge of the BWP 305. That is, the UE 115 may transmit the S-SSB 320 in the sidelink BWP 310 such that the first starting resource block of the S-SSB 320 is offset from the second starting resource block of the sidelink BWP 310. The first starting resource block of the S-SSB 320 may refer to the resource block with the lowest index used to transmit the S-SSB 320 (e.g., the 0th resource block of the S-SSB 320), and the second starting resource block of the sidelink BWP 310 may refer to the resource block with the lowest index in the sidelink BWP 310 (e.g., the 0th resource block of the sidelink BWP 310). The center frequency for S-SSB reception may be at the 66th subcarrier within the 11 resource blocks S-SSB 320.

[0143] A UE 115 transmitting the S-SSB 320 may indicate (e.g., to a UE 115 receiving the S-SSB 320) an offset 325 between a starting resource block of the S-SSB 320 and a starting resource block of the sidelink BWP 310. In some cases, the S-SSB may not support RMSI, and the UE 115 may transmit an indication of the offset 325 in a master information block (MIB) transmitted with the S-SSB 320. The S-SSB 320 may share a synchronization raster with the SSB 315-a and the SSB 315-b. That is, the S-SSB 320 in the sidelink BWP 310 (i.e., the S-SSB on the 20 MHz channel edge) and the SSBs 315-a and 315-b (e.g., the NR-U SSBs) in the BWP 305 may have the same synchronization grid (e.g., the center frequencies of the S-SSB 320 and the SSBs 315-a and 315-b may be aligned). There may be no confusion between the SSB 315 and the S-SSB 320 because the UE 115 may transmit the S-SSB 320 using a primary synchronization signal (PSS) sequence that is different from the PSS sequence used by the base station to transmit the SSB 315.

[0144] In some aspects, the UE 115 may use reserved bits in the MIB (e.g., two reserved MIB fields) to transmit an indication of the offset 325. In other aspects, the UE 115 may use other bits in the MIB to transmit an indication of the offset 325 (e.g., other bits in the MIB may be reinterpreted as an indication of the offset 325). That is, the existing fields in the MIB may be reinterpreted to indicate the offset 325. In yet other aspects, the UE 115 may use some code points for TDD configuration (e.g., because these code points may be unused) to transmit an indication of the offset 325. NR-U may use three or four bits to indicate the resource block offset between the control resource set (coreset) and the SSB. In addition, NR may allocate four bits to indicate the subcarrier offset between the SSB and the common resource block (CRB). Thus, two MIB bits may be sufficient to indicate the offset 325. In some aspects, the sidelink BWP 310 may have a subcarrier level offset from the BWP 305 (e.g., NR-U BWP) because the sidelink MIB may have limited code points. Because NR may use four bits to indicate the subcarrier offset between the SSB and the CRB, the limited code points may be sufficient to indicate the subcarrier level offset between the sidelink BWP 310 and the BWP 305 (e.g., when NR-U uplink and downlink communications (NR-U UU) are time-division multiplexed with sidelink communications (PC-5)).

[0145] Figure 4 An example of a location 400 of an SSB transmission in accordance with aspects of the present disclosure is illustrated. A UE 115 may identify a sidelink BWP 405 in a shared spectrum, and the UE 115 may transmit an S-SSB 410 in the sidelink BWP 405. The S-SSB 410 may span 11 resource blocks and may be aligned with a lower edge of the sidelink BWP 405. That is, the UE 115 may transmit the S-SSB 410 in the sidelink BWP 405 such that the S-SSB 410 and the sidelink BWP 405 share the same starting resource block. The same starting resource block of the S-SSB 410 and the sidelink BWP 405 may refer to a resource block with a lowest index for transmitting the S-SSB 410, which may be the same as a resource block with a lowest index in the sidelink BWP 405 (e.g., the 0th resource block of the sidelink BWP 405 may be aligned with the 0th resource block for transmitting the S-SSB 410). Thus, UE 115 may select a synchronization raster for S-SSB 410 so that S-SSB 410 is aligned with the lower edge of the 20 MHz channel. That is, the first synchronization raster for S-SSB 410 may be different from the second synchronization raster for downlink SSBs in the shared spectrum.

[0146] If Figure 4 4. If the S-SSB 410 illustrated in FIG. 1 is aligned with the lower edge of the sidelink BWP 405, the S-SSB 410 may overlap with a physical sidelink control channel (PSCCH) (e.g., if the PSCCH is transmitted in an interleaved manner on both edges of the sidelink BWP 405). For example, the UE 115 may transmit the PSCCH in an interleaved manner on the sidelink BWP 405 (e.g., across a 20 MHz bandwidth). Thus, Figure 4 As described in , the S-SSB transmission at the edge of the sidelink BWP 405 may overlap with the PSCCH. Figure 3 If the SSB is transmitted with an offset from the lower edge of the sidelink BWP as described in , the S-SSB transmission may not overlap with the PSCCH. For example, an offset between the S-SSB and the lower edge of the sidelink BWP may be defined to prevent the S-SSB from overlapping with the PSCCH. In some cases, the sidelink BWP 405 may be aligned with the NR-U BWP.

[0147] Reference Figure 3 and Figure 4 The various aspects described may allow the UE 115 to identify a suitable location for S-SSB transmission in a sidelink BWP in a shared spectrum. In some cases, it may also be beneficial to provide a technique for efficiently beam sweeping S-SSBs in a shared spectrum. In some wireless communication systems, the number of S-SSBs within an S-SSB period may be defined. The S-SSB period may correspond to a time period allocated to the UE 115 for transmitting S-SSBs in a shared spectrum. For a subcarrier spacing of 15kHz in FR1 (e.g., a low frequency band, such as a sub-6GHz band), the UE 115 may transmit one S-SSB in a single time slot. For a subcarrier spacing of 30kHz in FR1, the UE 115 may transmit one S-SSB in a single time slot or two S-SSBs in the corresponding time slot. For a subcarrier spacing of 60kHz in FR1, the UE 115 may transmit one S-SSB in a single time slot or two or four S-SSBs in the corresponding time slot. For a subcarrier spacing of 30 kHz in FR2 (e.g., a high frequency band such as an mmW band), the UE 115 may transmit one S-SSB in a single time slot or two, four, eight, 16, or 32 S-SSBs in the corresponding time slot. For a subcarrier spacing of 60 kHz in FR2, the UE 115 may transmit one S-SSB in a single time slot or two, four, eight, 16, 32, or 64 S-SSBs in the corresponding time slot.

[0148] Thus, S-SSB beam sweeping may have a limited number of beams (e.g., for subcarrier spacing greater than or equal to 30 kHz in FR1). In some cases, to maximize the gain of performing beam sweeping, it may be appropriate to add more S-SSB time slots (e.g., time slots including SSBs) mapped to different beams. In some aspects, the maximum number of S-SSBs (K) within an S-SSB period may be increased (e.g., in FR1). For example, for a subcarrier spacing of 15 kHz in FR1, the maximum number of S-SSBs within an S-SSB period may be increased to two (e.g., {1, 2}), for a subcarrier spacing of 30 kHz in FR1, the maximum number of S-SSBs within an S-SSB period may be increased to four (e.g., {1, 2, 4}), or for a subcarrier spacing of 60 kHz, the maximum number of S-SSBs within an S-SSB period may be increased to eight (e.g., {1, 2, 4, 8}). In addition, UE 115 can be configured to transmit S-SSBs in contiguous time slots (e.g., with a sidelink time interval of zero). Because each S-SSB can occupy one time slot, an S-SSB burst can occupy up to 2 ms. An S-SSB burst can correspond to a group of S-SSBs (e.g., an S-SSB instance), each S-SSB being transmitted using a different beam.

[0149] Figure 5 Illustrate aspects of SSB transmission 500 in beam sweeping according to aspects of the present disclosure. Figure 5, UE 115 may perform an LBT procedure to obtain access to the opposite side link BWP for an S-SSB period 505 (e.g., 160 ms). UE 115 may then identify an S-SSB burst 510 to be transmitted in the S-SSB period 505. The S-SSB burst 510 may include two or more S-SSBs 515, including S-SSB 515-a, S-SSB 515-b, S-SSB 515-c, and S-SSB 515-d. UE 115 may then transmit each of the two or more S-SSBs 515 of the S-SSB burst 510 using a different beam in the S-SSB period 505. That is, the beam sweep of the S-SSB 515 may correspond to transmitting each S-SSB 515 in the S-SSB burst 510 using a different beam. Additionally, the S-SSBs 515 in the S-SSB burst 510 may be transmitted in contiguous time resources. That is, the UE 115 may transmit the S-SSBs 515 in the S-SSB burst 510 with a sidelink time interval of zero such that there are no gaps in the S-SSB burst 510. By avoiding gaps in the S-SSB burst 510, the UE 115 may prevent other UEs from gaining access to the sidelink channel for transmission when the UE 115 is using the sidelink channel.

[0150] In some cases, in addition to transmitting an S-SSB burst having multiple S-SSBs in an S-SSB period, it may be beneficial for UE 115 to transmit more S-SSBs in an S-SSB period to increase the likelihood that other UEs will be able to discover UE 115. Figure 6 Various aspects of SSB transmission 600 in beam sweeping according to various aspects of the present disclosure are illustrated. As illustrated, a UE 115 can transmit multiple S-SSB bursts 610 in an S-SSB period 605. For example, a wireless communication system can allow multiple contiguous S-SSB time slots (e.g., S-SSB instances) in each S-SSB burst to be swept beam, and multiple S-SSB bursts in each S-SSB period. Each S-SSB time slot in an S-SSB burst can be transmitted with a different beam (e.g., different from the beam used to transmit other S-SSB time slots in the S-SSB burst). In addition, each S-SSB burst can include the same or different beam sweeps (e.g., a first S-SSB burst having S-SSBs transmitted with a first set of beams and a second S-SSB burst having S-SSBs transmitted with a second set of beams). In some aspects, for a subcarrier spacing of 30 kHz, there can be four S-SSB slots within one S-SSB burst (e.g., which sweeps across up to four beams), and there can be up to two S-SSB bursts within an S-SSB period (e.g., 160 ms).

[0151] exist Figure 6 , UE 115 may perform an LBT procedure to obtain access to a sidelink BWP in a shared spectrum for an S-SSB period 605. UE 115 may then identify a plurality of S-SSB bursts 610 (e.g., S-SSB burst 610-a and S-SSB burst 610-b) to transmit in S-SSB period 605. Each S-SSB burst may include two or more S-SSBs 615. For example, S-SSB burst 610-a may include S-SSB 615-a, S-SSB 615-b, S-SSB 615-c, and S-SSB 615-d, and S-SSB burst 610-b may include S-SSB 615-e, S-SSB 615-f, S-SSB 615-g, and S-SSB 615-h. The UE 115 may then use a different beam in the S-SSB period 610 to transmit each of the two or more S-SSBs 615 in each S-SSB burst 610. That is, the beam used to transmit the S-SSB 615 in each S-SSB burst 610 may be the same or different. The UE 115 may also select a sidelink time interval for each of the multiple S-SSB bursts 610 such that the multiple S-SSB bursts 610 are non-overlapping in the S-SSB period. That is, the time interval between two S-SSBs 615 may be selected such that the S-SSB bursts 610 are non-overlapping.

[0152] In some cases, base station 105 may configure UE 115 to transmit a specific number of S-SSB bursts in an S-SSB period. For example, base station 105 may transmit an indication of the number (e.g., quantity) of S-SSB bursts that UE 115 is to transmit in an S-SSB period. Figure 5 In, base station 105 may transmit an indication to UE 115 that it is to transmit an S-SSB burst in the S-SSB period, and in Figure 6 In the example embodiment, the base station 105 may transmit an indication to the UE 115 that two S-SSB bursts are to be transmitted in the S-SSB period. In other cases, the UE 115 may be preconfigured with a certain number of S-SSB bursts to transmit in the S-SSB period (e.g., installed in the profile of the UE 115). In addition, when the UE 115 transmits an S-SSB in a time slot, the UE 115 may transmit the MIB along with the S-SSB. The UE 115 may also transmit an indication of a time slot index in the MIB, and the time slot index may indicate a beam index of a beam used to transmit the S-SSB (e.g., after the receiving UE 115 decodes the payload of the MIB). That is, if the receiving UE 115 is able to identify the S-SSB pattern, the time slot index may be remapped to an S-SSB beam index.

[0153] Additionally or alternatively, the UE 115 may transmit a demodulation reference signal (DMRS) in conjunction with (e.g., together with) the S-SSB, and the UE 115 may indicate a beam index of a beam used to transmit the S-SSB in a DMRS scrambling sequence (e.g., in a case where the UE 115 cannot identify an S-SSB pattern, such as for initial access). That is, the UE 115 may identify a beam used to transmit an S-SSB in an S-SSB burst, and the UE 115 may encode at least a portion (e.g., two or three bits) of a DMRS scrambling sequence included with the S-SSB based on the beam index of the identified beam. For example, the UE 115 may set an initialization seed for encoding according to the beam index of the identified beam. The receiving UE 115 may receive the S-SSB and the DMRS scrambling sequence together with the S-SSB, and the receiving UE 115 may blindly decode at least a portion of the DMRS scrambling sequence to identify the beam index of the beam used to transmit the S-SSB. For example, the receiving UE 115 may perform blind decoding based on four or eight blind decoding hypotheses to determine the S-SSB beam index.

[0154] Figure 7 Various aspects of SSB transmission 700 in a DRS window according to various aspects of the present disclosure are explained. As described above, before transmitting an S-SSB in a shared spectrum, the UE 115 may perform an LBT procedure to obtain access to a peer link BWP to transmit the S-SSB. However, in some cases, some attempts to obtain access to the peer link BWP (e.g., some LBT procedures) may fail. In order to allow multiple opportunities or attempts in a successful LBT procedure, it may be beneficial for the UE 115 to be configured with multiple starting positions (e.g., S-SSB sweeps) for transmitting the S-SSB. As described herein, the DRS window 705 may be configured with multiple starting positions at which the UE 115 may start transmitting an S-SSB (e.g., start an S-SSB burst). That is, the DRS window 705 may be defined to allow multiple starting positions for up to K adjacent S-SSB transmissions. In some cases (e.g., in NR-U), the DRS window 705 may span 5 ms and may include contiguous SSB transmissions for up to a certain number of S-SSBs (e.g., X S-SSBs, where X=1, 2, 4, or 8).

[0155] The DRS window 705 may be allocated to the UE 115 to transmit a plurality of S-SSBs 715, including S-SSB 715-a, S-SSB 715-b, S-SSB 715-c, and SSB 715-d. The UE 115 may identify a DRS window 705 including a plurality of starting positions for transmitting the S-SSB 715, and the UE 115 may perform an LBT procedure to gain access to the DRS window 705 in the shared spectrum. The UE 115 may then transmit the S-SSB 715 at a first starting position in the plurality of starting positions after gaining access to the DRS window 705. The first starting position may correspond in time to a starting position that is closest in time to the time at which the UE 115 gains access to the DRS window 705. Figure 7 , UE 115 may perform a first LBT procedure before starting position 720-a, but the LBT procedure may fail. Therefore, UE 115 may avoid transmitting sweep burst 710 at starting position 720-a. UE 115 may then perform a second LBT procedure before starting position 720-b, and the second LBT procedure may be successful (i.e., the channel may be clear). Therefore, UE 115 may transmit sweep burst 710 starting at starting position 720-b.

[0156] In some aspects, the maximum number of S-SSBs in an S-SSB burst may be represented by K, and the number of time slots in the DRS window may be represented by Y. In such aspects, for a subcarrier spacing of 15 kHz, if K is equal to 1, and Y is equal to 2, then there may be two starting positions (e.g., LBT starting positions) in the DRS window. For a subcarrier spacing of 30 kHz, if K is equal to 2, and Y is equal to 4, then there may be three starting positions in the DRS window. For a subcarrier spacing of 60 kHz, if K is equal to 4, and Y is equal to 8, then there may be four starting positions in the DRS window. In the aspects described above, the DRS window 705 may span 4 time slots, such as Figure 7 In some cases, when UE 115 transmits a physical sidelink broadcast channel (PSBCH) (e.g., including an S-SSB) in a time slot in a DRS window, UE 115 may transmit a time slot number in the PBSCH, which indicates the time slot number including the PBSCH. In such a case, UE 115 may also transmit a DMRS scrambling sequence indicating a beam index of a beam used to transmit the S-SSB together with the S-SSB.

[0157] Figure 8Various aspects of SSB transmission 800 across multiple time slots according to various aspects of the present disclosure are illustrated. In various aspects described above, UE 115 may transmit multiple S-SSBs (e.g., in S-SSB bursts) across multiple time slots. However, in some cases, the last symbol at the end of the time slot that includes the S-SSB may be empty. Therefore, even when UE 115 is configured to transmit multiple S-SSBs back-to-back (e.g., in adjacent time slots), there may be a gap of one symbol at the end of the time slot. In such a situation, other devices (e.g., UE 115, Wi-Fi devices) may determine that the channel used to transmit the S-SSB is clear during the gap, and these other devices may transmit signals that may interfere with the S-SSB during the gap. As described herein, UE 115 may fill the gaps between S-SSBs to prevent other devices from accessing the channel between S-SSBs transmitted in the shared spectrum.

[0158] In the first aspect 800-a, the UE 115 may identify a first S-SSB to be transmitted in a first time slot 805-a and a second S-SSB to be transmitted in a second time slot 805-b. The UE 115 may then generate a PBCH repetition 810 to fill the gap between the first S-SSB and the second S-SSB, and the UE 115 may transmit the first S-SSB in the first time slot 805-a and the second S-SSB in the second time slot 805-b along with the PBCH repetition 810 between the first S-SSB and the second S-SSB. That is, the UE 115 may fill the gap in the middle of the S-SSB burst with the PBCH repetition. In some cases, if the UE 115 is not scheduled to transmit in the shared spectrum after the last S-SSB in the last time slot (e.g., the S-SSB in the second time slot 805-b), the UE 115 may avoid filling the last symbol of the last time slot. That is, the UE 115 may fill the 13th symbol of one or more time slots with PBCH repetitions, except for the 13th symbol of the time slot that includes the last S-SSB in the S-SSB sweep burst. In a first aspect, the UE 115 may prevent other devices (or nodes) from jumping in during the gap of one symbol between the first time slot 805-a and the second time slot 805-b. In addition, the PBCH repetition 810 may be a repetition of the PBCH in a previous symbol (e.g., symbol 12 of the first time slot 805-a).

[0159] In the second aspect 800-b, the UE 115 may identify a first S-SSB to be transmitted in a first time slot 805-c and a second S-SSB to be transmitted in a second time slot 805-d. The UE 115 may then generate a cyclic prefix (CP) extension 815 to fill the gap between the first S-SSB and the second S-SSB, and the UE 115 may transmit the first S-SSB in the first time slot 805-c and the second S-SSB in the second time slot 805-d together with the CP extension 815 between the first S-SSB and the second S-SSB. That is, the UE 115 may fill the gap in the middle of the S-SSB burst with the CP extension. In some cases, if the UE 115 is not scheduled to transmit in the shared spectrum after the last S-SSB in the last time slot (e.g., the S-SSB in the second time slot 805-c), the UE 115 may avoid filling the last symbol of the time slot. That is, the UE 115 may fill the 13th symbol of one or more time slots with a CP extension, except for the 13th symbol of the time slot that includes the last S-SSB in the S-SSB sweep burst. In a second aspect, the UE 115 may prevent other devices (or nodes) from jumping in during the gap of one symbol between the first time slot 805-c and the second time slot 805-d. In some cases, the CP extension 815 may be from the first PBCH symbol in the next time slot (e.g., symbol 1 of the second time slot 805-d). Additionally or alternatively, the CP extension 815 may be a suffix extension (e.g., of the last symbol of the S-SSB).

[0160] In various aspects described herein, UE 115 may execute LBT procedures to gain access to a side link channel in a shared spectrum to transmit S-SSB. For FR1, the S-SSB sweep burst may be less than or equal to 1 or 2 ms within a 160 ms period. Therefore, a category 2 procedure for accessing a shared spectrum for S-SSB transmission may be preferred, but may not be used when the side link node supports asynchronous operation. In contrast, a category 4 procedure for accessing a shared spectrum for S-SSB transmission may be supported. Therefore, in some cases, UE 115 may execute a category 2 procedure with the highest priority to access a side link channel for S-SSB transmission. In other cases, UE 115 may execute a category 4 procedure with the highest priority to access a side link channel for S-SSB transmission.

[0161] In some cases, the sidelink may have a certain received signal received power (RSRP) criterion for enabling the UE 115 to become a synchronization node for transmitting the S-SSB. For example, a UE that does not identify a synchronization reference signal (e.g., NR-USSB) that satisfies an RSRP threshold may be allowed to transmit an S-SSB, while a UE that identifies at least one synchronization reference signal that satisfies an RSRP threshold may be prohibited from transmitting an S-SSB. In addition, as mentioned above, a beam sweeping procedure for S-SSB transmission may be introduced to improve the link quality between UEs 115 (e.g., particularly in FR2). In NR-uu (e.g., uplink and downlink communications), the beam sweeping procedure may rely on SSB repetition and beam sweeping, and the receiving UE 115 may use the corresponding physical random access channel (PRACH) resource to select the transmit beam of the transmitting UE 115. In sidelink communications, it may be beneficial to associate each S-SSB beam with a corresponding physical sidelink feedback channel (PSFCH) or PRACH resource. That is, the PRACH may be used in sidelink communications (e.g., on a PC5 interface). Because the PSFCH or PRACH resource may correspond to an S-SSB beam, the receiving UE 115 may select the PSFCH or PRACH resource to indicate a preferred transmit beam (e.g., a beam for a UE 115 transmitting an S-SSB to use for transmissions to the receiving UE 115). Additionally or alternatively, the receiving UE 115 may use a physical sidelink shared channel (PSSCH) to indicate a preferred beam.

[0162] In some aspects, the UE 115 may perform an LBT procedure to gain access to a sidelink BWP in a shared spectrum for an S-SSB period, and the UE 115 may transmit one or more S-SSBs using one or more beams in the S-SSB period, wherein each S-SSB is transmitted using a different beam. The UE 115 may then receive an indication of a preferred beam from another UE 115 of the one or more beams for transmitting sidelink data to the other UE 115. The UE 115 may then transmit the sidelink data to the other UE 115 on the preferred beam. In one aspect, the UE 115 may receive signaling on a PSFCH resource corresponding to (e.g., mapped to) an S-SSB, and the UE 115 may determine that the beam used to transmit the S-SSB is the preferred beam. On the other hand, UE 115 can receive signaling on a PRACH resource corresponding to an S-SSB (e.g., mapped to an S-SSB), and UE 115 can determine that the beam used to transmit the S-SSB is the preferred beam. On the other hand, UE 115 can receive an indication of the preferred beam in a PSSCH.

[0163] By transmitting S-SSBs using beam sweeping, a UE 115 may be able to identify a suitable beam for communicating with another UE 115 on a sidelink connection. However, in some cases, S-SSB sweeping that always uses all possible beams or a large number of beams in the corresponding S-SSB slot may result in large overhead and may cause interference to other links. As described herein, the UE 115 may support a mechanism for turning S-SSB beam sweeping on and off (e.g., with long S-SSB bursts). To further limit overhead, in some aspects, the periodicity of the S-SSB transmissions may be long. In such aspects, a beam management procedure based on a channel state information reference signal (CSI-RS) may be introduced to allow the UE 115 to perform beam recovery (e.g., based on the S-SSB) in the time between periodic S-SSB transmissions.

[0164] Fig. 9 Various aspects of on-demand S-SSB sweeping 900 according to various aspects of the present disclosure are illustrated. If a UE 115 is triggered by another UE 115 (e.g., if indicated by layer one or layer two signaling), the UE 115 may sweep all S-SSB beams or a certain number of S-SSB beams. In some cases, there may be two numbers (e.g., X and Y) of beams or S-SSBs within one S-SSB period. The smaller number (e.g., X) may be a default value for S-SSB burst transmission, while the larger number (e.g., Y) may be the number of beams to be used for S-SSB transmission when the UE 115 is triggered. Therefore, if on-demand S-SSB sweeping is not triggered, the transmitting UE 115 may transmit X S-SSBs in each S-SSB period to reduce overhead. Alternatively, the receiving UE 115 may trigger a beam management procedure at the transmitting UE 115, and the transmitting UE 115 may transmit Y S-SSBs in the upcoming S-SSB period. The S-SSB beam sweeping triggered on demand may have a different set of beams than the beams used in the default S-SSB burst. For example, the UE 115 may employ one or more wide beams to transmit the default S-SSB burst, and the UE 115 may employ narrower beams to perform the triggered S-SSB beam sweeping for beam perfection (e.g., of one or more of the wide beams).

[0165] exist Fig. 9, UE 115 may perform an LBT procedure to obtain access to a sidelink BWP in a shared spectrum for an S-SSB period 905. UE 115 may then determine whether to transmit a first number of S-SSBs or a second number of S-SSBs in the S-SSB period 905, wherein the first number is greater than the second number. Because UE 115 may not receive a trigger for transmitting the first number of S-SSBs in the S-SSB period 905, UE 115 may transmit the second number of S-SSBs in the S-SSB period 905. Specifically, UE 115 may transmit a single S-SSB 915-a in the S-SSB period 905. UE 115 may then receive a trigger 910 for transmitting the first number of S-SSBs in the next S-SSB period (not shown). As a result, UE 115 may transmit a sweep burst 920 in the next S-SSB period. Specifically, UE 115 may transmit S-SSB 915-b, S-SSB 915-c, S-SSB 915-d, and S-SSB 915-e in swept burst 920 using one or more beams (e.g., as part of a beam refinement procedure). UE 115 may transmit each of S-SSB 915 in swept burst 920 using a different beam.

[0166] In some cases, UE 115 may transmit both the first number of S-SSBs and the second number of S-SSBs in the same S-SSB period. In such a case, UE 115 may be able to support the upcoming S-SSB burst sweep to perform beam perfection in the middle of a long S-SSB period. Fig.10 Illustrated are aspects of an on-demand S-SSB sweep 1000 including multiple S-SSB burst transmissions in a single S-SSB period 1005 in accordance with aspects of the present disclosure. Fig.10 1005. UE 115 may also perform an LBT procedure to obtain access to a sidelink BWP in the shared spectrum for S-SSB period 1005. UE 115 may then determine whether to transmit a first number of S-SSBs or a second number of S-SSBs in S-SSB period 1005, where the first number is greater than the second number. Because UE 115 may not receive a trigger for transmitting the first number of S-SSBs before the start of S-SSB period 905, UE 115 may transmit the second number of S-SSBs in S-SSB period 1005. Specifically, UE 115 may transmit a single S-SSB 1015-a in S-SSB period 1005.

[0167] The UE 115 may then receive a trigger 1010 for transmitting a first number of S-SSBs in the S-SSB period 1005. As a result, the UE 115 may transmit a swept burst 1020 in the S-SSB period 1005. Specifically, the UE 115 may transmit the S-SSB 1015-b and the S-SSB 1015-c in the swept burst 1020 using one or more beams (e.g., as part of a beam refinement procedure). The UE 115 may transmit each of the S-SSBs 1015 in the swept burst 1020 using a different beam. The UE 115 may transmit the on-demand S-SSB swept burst 1020 at a predefined or preconfigured amount of time (e.g., Z time slots) after receiving the trigger. However, in some aspects, transmitting the S-SSB sweep burst 1020 in the S-SSB period 1005 may cause dynamic interference to other UE pairs because the other UE pairs may not identify the dynamic S-SSB transmission (e.g., because the other UE pairs may not be able to determine a predefined or preconfigured amount of time between the trigger 1010 and the S-SSB sweep burst 1020).

[0168] In reference Fig. 9 and Fig.10 In both aspects described, UE 115 may receive a trigger for performing on-demand S-SSB beam sweeping. UE 115 may receive the trigger in layer one or layer two signaling from another UE 115 or base station 105. Layer one signaling may be a reserved PRACH resource that may trigger on-demand S-SSB sweeping or side link control information (SCI) on the reverse link (e.g., phase two SCI) that may trigger on-demand S-SSB sweeping (e.g., SCI in PSSCH). Layer two signaling may be a MAC-CE in the reverse link that may trigger on-demand S-SSB sweeping. After the on-demand S-SSB transmission, if no trigger is received, the transmitting UE 115 may transmit a default number of S-SSBs in an S-SSB period (e.g., the next S-SSB period).

[0169] Fig.11 A block diagram 1100 of a device 1105 supporting S-SSB transmissions in a shared spectrum according to aspects of the present disclosure is shown. The device 1105 may be an example of aspects of a UE 115 as described herein. The device 1105 may include a receiver 1110, a communication manager 1115, and a transmitter 1120. The device 1105 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0170] The receiver 1110 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to S-SSB transmissions in a shared spectrum, etc.). The information may be passed to other components of the device 1105. The receiver 1110 may be a reference Fig.14 Examples of various aspects of the described transceiver 1420. The receiver 1110 may utilize a single antenna or a collection of antennas.

[0171] The communication manager 1115 can: perform a listen-before-talk procedure to obtain access to a side link bandwidth portion in a shared spectrum for side link communication; identify a side link synchronization signal block to be transmitted in the side link bandwidth portion; and transmit the side link synchronization signal block in the side link bandwidth portion so that a first starting resource block of the side link synchronization signal block is offset from a second starting resource block of the side link bandwidth portion.

[0172] The communication manager 1115 can also: identify a side link bandwidth portion in the shared spectrum that includes a side link synchronization signal block; receive a master information block indicating an offset between a first starting resource block of the side link synchronization signal block and a second starting resource block of the side link bandwidth portion; and decode the side link synchronization signal block in the side link bandwidth portion based on the received master information block indicating the offset.

[0173] The communication manager 1115 can also: perform a listen-before-talk procedure to obtain access to a side link bandwidth portion in a shared spectrum for side link communications; identify a side link synchronization signal block to be transmitted in the side link bandwidth portion; and transmit the side link synchronization signal block in the side link bandwidth portion so that the side link synchronization signal block shares the same starting resource block as the side link bandwidth portion.

[0174] The communication manager 1115 can also: perform a listen-before-talk procedure to obtain access to a side link bandwidth portion in a shared spectrum for a side link synchronization signal block period; identify a side link synchronization signal block burst to be transmitted in the side link synchronization signal block period, the side link synchronization signal block burst comprising two or more side link synchronization signal blocks; and transmit each of the two or more side link synchronization signal blocks in the side link synchronization signal block burst using a different beam, wherein the two or more side link synchronization signal blocks in the side link synchronization signal block burst are transmitted in adjacent time resources.

[0175] The communication manager 1115 can also: identify a side link synchronization signal block period having a side link synchronization signal block burst including two or more side link synchronization signal blocks (each side link synchronization signal block is transmitted using a different beam); and receive a side link synchronization signal block burst including two or more side link synchronization signal blocks in adjacent time resources.

[0176] The communication manager 1115 may also: perform a listen-before-talk procedure to obtain access to a side link bandwidth portion in a shared spectrum for a side link synchronization signal block period; identify a set of side link synchronization signal block bursts to be transmitted in the side link synchronization signal block period, each side link synchronization signal block burst comprising two or more side link synchronization signal blocks; and transmit each of the two or more side link synchronization signal blocks in each side link synchronization signal block burst in the side link synchronization signal block period using a different beam.

[0177] The communication manager 1115 can also: identify a side link synchronization signal block period having a set of side link synchronization signal block bursts, each side link synchronization signal block burst including two or more side link synchronization signal blocks, and each of the two or more side link synchronization signal blocks is transmitted using a different beam; and receive the side link synchronization signal block burst set in the side link synchronization signal block period.

[0178] The communication manager 1115 can also: identify a DRS window in a shared spectrum that includes a set of starting positions for transmitting one or more side link synchronization signal blocks; perform a listen-before-talk procedure to gain access to a discovery reference signal window in the shared spectrum; and after gaining access to the discovery reference signal window in the shared spectrum, transmit one or more side link synchronization signal blocks at a first starting position in the set of starting positions.

[0179] The communication manager 1115 can also: identify a DRS window in the shared spectrum in which one or more side link synchronization signal blocks are to be received; determine that a reference signal window includes a set of starting positions for receiving one or more side link synchronization signal blocks; and monitor the set of starting positions to find one or more side link synchronization signal blocks in the reference signal window.

[0180] The communication manager 1115 can also: identify a first side link synchronization signal block to be transmitted in a first time slot and a second side link synchronization signal block to be transmitted in a second time slot in the side link bandwidth portion of the shared spectrum; generate a PBCH repetition or a cyclic prefix extension to fill a gap between the first side link synchronization signal block and the second side link synchronization signal block; and transmit the first side link synchronization signal block in the first time slot and the second side link synchronization signal block in the second time slot together with a physical broadcast channel repetition or cyclic prefix extension between the first side link synchronization signal block and the second side link synchronization signal block.

[0181] The communication manager 1115 may also: perform a listen-before-talk procedure to obtain access to a sidelink bandwidth portion in a shared spectrum for a sidelink synchronization signal block period; transmit one or more sidelink synchronization signal blocks using one or more beams in the sidelink synchronization signal block period, each of the one or more sidelink synchronization signal blocks being transmitted using a different beam; and receive, from a second UE based on transmitting the one or more sidelink synchronization signal blocks, an indication of a preferred beam of the one or more beams for transmitting sidelink data to the second UE.

[0182] The communication manager 1115 can also: receive one or more side link synchronization signal blocks transmitted using one or more beams from a second UE in a side link synchronization signal block period, each of the one or more side link synchronization signal blocks being transmitted using a different beam; select a preferred beam among the one or more beams for the second UE to use to transmit side link data to the first UE; and transmit an indication of the preferred beam to the second UE based on the selection.

[0183] The communication manager 1115 can also: execute a listen-before-talk procedure to obtain access to the side link bandwidth portion in the shared spectrum for a side link synchronization signal block period; determine whether to transmit a first number or a second number of side link synchronization signal blocks in the side link synchronization signal block period, the first number being greater than the second number; and transmit the first number or the second number of side link synchronization signal blocks in the side link synchronization signal block period based on the determination.

[0184] The communication manager 1115 may also: determine whether to receive a first number or a second number of sidelink synchronization signal blocks from the second UE in a sidelink synchronization signal block period, the first number being greater than the second number; identify a sidelink synchronization signal block period having the first number or the second number of sidelink synchronization signal blocks; and receive the first number or the second number of sidelink synchronization signal blocks in the sidelink synchronization signal block period based on the determination. The communication manager 1115 may be an example of aspects of the communication manager 1410 described herein.

[0185] The communication manager 1115 or its subcomponents may be implemented in hardware, in code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communication manager 1115 or its subcomponents may be performed by a general purpose processor, a DSP, an application specific integrated circuit (ASIC), an FPGA or other programmable logic device designed to perform the functions described in the present disclosure, discrete gate or transistor logic, discrete hardware components, or any combination thereof.

[0186] The communication manager 1115 or its subcomponents may be physically located at various locations, including being distributed such that portions of functionality are implemented by one or more physical components at different physical locations. In some examples, according to various aspects of the present disclosure, the communication manager 1115 or its subcomponents may be separate and distinct components. In some examples, according to various aspects of the present disclosure, the communication manager 1115 or its subcomponents may be combined with one or more other hardware components, including but not limited to input / output (I / O) components, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof.

[0187] The transmitter 1120 may transmit signals generated by other components of the device 1105. In some examples, the transmitter 1120 may be co-located with the receiver 1110 in a transceiver module. For example, the transmitter 1120 may be a reference Fig.14 Examples of aspects of the described transceiver 1420. The transmitter 1120 may utilize a single antenna or a collection of antennas.

[0188] Fig.12 A block diagram 1200 of a device 1205 supporting S-SSB transmissions in a shared spectrum according to aspects of the present disclosure is shown. The device 1205 may be an example of aspects of the device 1105 or UE 115 as described herein. The device 1205 may include a receiver 1210, a communication manager 1215, and a transmitter 1255. The device 1205 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0189] Receiver 1210 may receive information, such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to S-SSB transmissions in a shared spectrum, etc.). The information may be passed to other components of device 1205. Receiver 1210 may be a reference Fig.14 Examples of aspects of the described transceiver 1420. The receiver 1210 may utilize a single antenna or a collection of antennas.

[0190] The communication manager 1215 may be an example of aspects of the communication manager 1115 as described herein. The communication manager 1215 may include an LBT manager 1220, an S-SSB manager 1225, a MIB manager 1230, a decoder 1235, an S-SSB burst manager 1240, a DRS window manager 1245, and a beam manager 1250. The communication manager 1215 may be an example of aspects of the communication manager 1410 described herein.

[0191] The LBT manager 1220 may perform a listen-before-talk procedure to gain access to a sidelink bandwidth portion in a shared spectrum for sidelink communications. The S-SSB manager 1225 may identify a sidelink synchronization signal block to be transmitted in the sidelink bandwidth portion and transmit the sidelink synchronization signal block in the sidelink bandwidth portion such that a first starting resource block of the sidelink synchronization signal block is offset from a second starting resource block of the sidelink bandwidth portion.

[0192] The S-SSB manager 1225 may identify a sidelink bandwidth portion of the shared spectrum that includes a sidelink synchronization signal block. The MIB manager 1230 may receive a master information block indicating an offset between a first starting resource block of the sidelink synchronization signal block and a second starting resource block of the sidelink bandwidth portion. The decoder 1235 may decode the sidelink synchronization signal block in the sidelink bandwidth portion based on receiving the master information block indicating the offset.

[0193] The LBT manager 1220 may perform a listen-before-talk procedure to gain access to a sidelink bandwidth portion in a shared spectrum for sidelink communications. The S-SSB manager 1225 may identify a sidelink synchronization signal block to be transmitted in the sidelink bandwidth portion and transmit the sidelink synchronization signal block in the sidelink bandwidth portion such that the sidelink synchronization signal block shares the same starting resource block as the sidelink bandwidth portion.

[0194] The LBT manager 1220 may perform a listen-before-talk procedure to obtain access to a sidelink bandwidth portion in a shared spectrum for a sidelink synchronization signal block period. The S-SSB burst manager 1240 may identify a sidelink synchronization signal block burst to be transmitted in a sidelink synchronization signal block period, the sidelink synchronization signal block burst comprising two or more sidelink synchronization signal blocks. The S-SSB manager 1225 may transmit each of two or more sidelink synchronization signal blocks of a sidelink synchronization signal block burst using a different beam, wherein the two or more sidelink synchronization signal blocks in the sidelink synchronization signal block burst are transmitted in contiguous time resources.

[0195] The S-SSB manager 1225 may identify a sidelink synchronization signal block period having a sidelink synchronization signal block burst including two or more sidelink synchronization signal blocks, each of which is transmitted using a different beam. The S-SSB burst manager 1240 may receive a sidelink synchronization signal block burst including two or more sidelink synchronization signal blocks in a contiguous time resource.

[0196] The LBT manager 1220 may perform a listen-before-talk procedure to obtain access to the sidelink bandwidth portion in the shared spectrum for a sidelink synchronization signal block period. The S-SSB burst manager 1240 may identify a set of sidelink synchronization signal block bursts to be transmitted in a sidelink synchronization signal block period, each sidelink synchronization signal block burst including two or more sidelink synchronization signal blocks. The S-SSB manager 1225 may transmit each of the two or more sidelink synchronization signal blocks in each sidelink synchronization signal block burst using a different beam in the sidelink synchronization signal block period.

[0197] The S-SSB manager 1225 may identify a sidelink synchronization signal block period having a set of sidelink synchronization signal block bursts, each sidelink synchronization signal block burst including two or more sidelink synchronization signal blocks, and each of the two or more sidelink synchronization signal blocks is transmitted using a different beam. The S-SSB burst manager 1240 may receive the set of sidelink synchronization signal block bursts in the sidelink synchronization signal block period.

[0198] The DRS window manager 1245 may identify a discovery reference signal (DRS) window in the shared spectrum that includes a set of starting positions for transmitting one or more side link synchronization signal blocks. The LBT manager 1220 may perform a listen-before-talk procedure to obtain access to the discovery reference signal window in the shared spectrum. The S-SSB manager 1225 may transmit one or more side link synchronization signal blocks at a first starting position in the set of starting positions after obtaining access to the discovery reference signal window in the shared spectrum.

[0199] The DRS window manager 1245 may identify a discovery reference signal (DRS) window in the shared spectrum in which to receive one or more side link synchronization signal blocks, and determine that the discovery reference signal window includes a set of starting positions for receiving the one or more side link synchronization signal blocks. The S-SSB manager 1225 may monitor the set of starting positions to find one or more side link synchronization signal blocks in the discovery reference signal window.

[0200] The S-SSB manager 1225 can: identify a first side link synchronization signal block to be transmitted in a first time slot and a second side link synchronization signal block to be transmitted in a second time slot in the side link bandwidth portion of the shared spectrum; generate a PBCH repetition or a cyclic prefix extension to fill a gap between the first side link synchronization signal block and the second side link synchronization signal block; and transmit the first side link synchronization signal block in the first time slot and the second side link synchronization signal block in the second time slot together with a physical broadcast channel repetition or a cyclic prefix extension between the first side link synchronization signal block and the second side link synchronization signal block.

[0201] The LBT manager 1220 may perform a listen-before-talk procedure to obtain access to the sidelink bandwidth portion in the shared spectrum for a sidelink synchronization signal block period. The S-SSB manager 1225 may transmit one or more sidelink synchronization signal blocks using one or more beams in the sidelink synchronization signal block period, each of the one or more sidelink synchronization signal blocks being transmitted using a different beam. The beam manager 1250 may receive, from the second UE based on transmitting the one or more sidelink synchronization signal blocks, an indication of a preferred beam of the one or more beams for transmitting sidelink data to the second UE.

[0202] The S-SSB manager 1225 may receive one or more sidelink synchronization signal blocks transmitted using one or more beams from the second UE in a sidelink synchronization signal block period, each of the one or more sidelink synchronization signal blocks being transmitted using a different beam. The beam manager 1250 may select a preferred beam from the one or more beams for the second UE to use to transmit sidelink data to the first UE, and transmit an indication of the preferred beam to the second UE based on the selection.

[0203] The LBT manager 1220 may perform a listen-before-talk procedure to obtain access to the sidelink bandwidth portion in the shared spectrum for a sidelink synchronization signal block period. The S-SSB manager 1225 may: determine whether a first number or a second number of sidelink synchronization signal blocks are to be transmitted in a sidelink synchronization signal block period, the first number being greater than the second number; and transmit the first number or the second number of sidelink synchronization signal blocks in the sidelink synchronization signal block period based on the determination.

[0204] The S-SSB manager 1225 may: determine whether a first number or a second number of sidelink synchronization signal blocks are to be received from a second UE in a sidelink synchronization signal block period, the first number being greater than the second number; identify a sidelink synchronization signal block period having the first number or the second number of sidelink synchronization signal blocks; and receive the first number or the second number of sidelink synchronization signal blocks in the sidelink synchronization signal block period based on the determination.

[0205] The transmitter 1255 may transmit signals generated by other components of the device 1205. In some examples, the transmitter 1255 may be co-located with the receiver 1210 in a transceiver module. Fig.14 Examples of various aspects of the described transceiver 1420. The transmitter 1255 may utilize a single antenna or a collection of antennas.

[0206] Fig.13A block diagram 1300 of a communication manager 1305 supporting S-SSB transmission in a shared spectrum in accordance with aspects of the present disclosure is shown. The communication manager 1305 may be an example of aspects of the communication manager 1115, the communication manager 1215, or the communication manager 1410 described herein. The communication manager 1305 may include an LBT manager 1310, an S-SSB manager 1315, a MIB manager 1320, a decoder 1325, an S-SSB burst manager 1330, a beam manager 1335, an encoder 1340, a DMRS manager 1345, a DRS window manager 1350, a PBCH manager 1355, a CP extension manager 1360, and a sidelink data manager 1365. Each of these modules may communicate directly or indirectly with each other (e.g., via one or more buses).

[0207] The LBT manager 1310 may perform a listen-before-talk procedure to obtain access to a sidelink bandwidth portion in a shared spectrum for sidelink communications. In some examples, the LBT manager 1310 may perform a listen-before-talk procedure to obtain access to a sidelink bandwidth portion in a shared spectrum for sidelink communications. In some examples, the LBT manager 1310 may perform a listen-before-talk procedure to obtain access to a sidelink bandwidth portion in a shared spectrum for a sidelink synchronization signal block period. In some examples, the LBT manager 1310 may perform a listen-before-talk procedure to obtain access to a sidelink bandwidth portion in a shared spectrum for a sidelink synchronization signal block period. In some examples, the LBT manager 1310 may perform a listen-before-talk procedure to obtain access to a discovery reference signal window in a shared spectrum. In some examples, the LBT manager 1310 may perform a listen-before-talk procedure to obtain access to a sidelink bandwidth portion in a shared spectrum for a sidelink synchronization signal block period. In some examples, the LBT manager 1310 may perform a listen-before-talk procedure to gain access to a sidelink bandwidth portion in a shared spectrum for a sidelink synchronization signal block period.

[0208] The S-SSB manager 1315 may identify a side link synchronization signal block to be transmitted in a side link bandwidth portion. In some examples, the S-SSB manager 1315 may transmit a side link synchronization signal block in a side link bandwidth portion so that a first starting resource block of the side link synchronization signal block is offset from a second starting resource block of the side link bandwidth portion. In some examples, the S-SSB manager 1315 may identify a side link bandwidth portion in a shared spectrum that includes a side link synchronization signal block. In some examples, the S-SSB manager 1315 may identify a side link synchronization signal block to be transmitted in a side link bandwidth portion. In some examples, the S-SSB manager 1315 may transmit a side link synchronization signal block in a side link bandwidth portion so that the side link synchronization signal block shares the same starting resource block with the side link bandwidth portion. In some examples, the S-SSB manager 1315 may transmit each of two or more side link synchronization signal blocks of a side link synchronization signal block burst using different beams, wherein two or more side link synchronization signal blocks in the side link synchronization signal block burst are transmitted in contiguous time resources.

[0209] In some examples, the S-SSB manager 1315 may identify a sidelink synchronization signal block period having a sidelink synchronization signal block burst including two or more sidelink synchronization signal blocks, each of which is transmitted using a different beam. In some examples, the S-SSB manager 1315 may use a different beam to transmit each of the two or more sidelink synchronization signal blocks in each sidelink synchronization signal block burst in the sidelink synchronization signal block period. In some examples, the S-SSB manager 1315 may identify a sidelink synchronization signal block period having a set of sidelink synchronization signal block bursts, each of which includes two or more sidelink synchronization signal blocks, and each of the two or more sidelink synchronization signal blocks is transmitted using a different beam. In some examples, the S-SSB manager 1315 may transmit one or more sidelink synchronization signal blocks at the first starting position in the starting position set after obtaining access to the discovery reference signal window in the shared spectrum.

[0210] In some examples, the S-SSB manager 1315 may monitor the starting position set to find one or more side link synchronization signal blocks in the discovery reference signal window. In some examples, the S-SSB manager 1315 may identify a first side link synchronization signal block to be transmitted in a first time slot and a second side link synchronization signal block to be transmitted in a second time slot in the side link bandwidth portion of the shared spectrum. In some examples, the S-SSB manager 1315 may generate a PBCH repetition or a cyclic prefix extension to fill the gap between the first side link synchronization signal block and the second side link synchronization signal block. In some examples, the S-SSB manager 1315 may transmit the first side link synchronization signal block in the first time slot and the second side link synchronization signal block in the second time slot together with a physical broadcast channel repetition or a cyclic prefix extension between the first side link synchronization signal block and the second side link synchronization signal block.

[0211] In some examples, the S-SSB manager 1315 may transmit one or more sidelink synchronization signal blocks using one or more beams in a sidelink synchronization signal block period, each of the one or more sidelink synchronization signal blocks being transmitted using a different beam. In some examples, the S-SSB manager 1315 may receive one or more sidelink synchronization signal blocks transmitted using one or more beams from a second UE in a sidelink synchronization signal block period, each of the one or more sidelink synchronization signal blocks being transmitted using a different beam. In some examples, the S-SSB manager 1315 may determine whether a first number or a second number of sidelink synchronization signal blocks is to be transmitted in a sidelink synchronization signal block period, the first number being greater than the second number. In some examples, the S-SSB manager 1315 may transmit the first number or the second number of sidelink synchronization signal blocks in a sidelink synchronization signal block period based on the determination.

[0212] In some examples, the S-SSB manager 1315 may determine whether to receive a first number or a second number of sidelink synchronization signal blocks from a second UE in a sidelink synchronization signal block period, the first number being greater than the second number. In some examples, the S-SSB manager 1315 may identify a sidelink synchronization signal block period having a first number or a second number of sidelink synchronization signal blocks. In some examples, the S-SSB manager 1315 may receive a first number or a second number of sidelink synchronization signal blocks in a sidelink synchronization signal block period based on the determination. In some examples, the S-SSB manager 1315 may transmit a sidelink synchronization signal block in the one or more sidelink synchronization signal blocks and an indication of a time slot including the synchronization signal block in a physical sidelink broadcast channel. In some examples, the S-SSB manager 1315 may transmit a sidelink synchronization signal block in the one or more sidelink synchronization signal blocks and a demodulation reference signal scrambling sequence indicating a beam index of a beam used to transmit the synchronization signal block in a physical sidelink broadcast channel.

[0213] In some examples, the S-SSB manager 1315 may receive a sidelink synchronization signal block in the one or more sidelink synchronization signal blocks and an indication of a time slot including the synchronization signal block in a physical sidelink broadcast channel. In some examples, the S-SSB manager 1315 may receive a sidelink synchronization signal block in the one or more sidelink synchronization signal blocks and a demodulation reference signal scrambling sequence indicating a beam index of a beam used to transmit the synchronization signal block in a physical sidelink broadcast channel. In some examples, the S-SSB manager 1315 may receive an indication from a second UE that a first number of sidelink synchronization signal blocks are to be transmitted in a sidelink synchronization signal block period. In some examples, the S-SSB manager 1315 may transmit a first number of sidelink synchronization signal blocks using one or more beams as part of a beam improvement procedure based on receiving the indication, each of the first number of sidelink synchronization signal blocks being transmitted using a different beam.

[0214] In some examples, the S-SSB manager 1315 may transmit the first number of side link synchronization signal blocks after a preconfigured time period after receiving an indication that the first number of side link synchronization signal blocks are to be transmitted. In some examples, the S-SSB manager 1315 may determine that a second number of side link synchronization signal blocks are to be transmitted based on a failure to receive an indication that the first number of side link synchronization signal blocks are to be transmitted in a side link synchronization signal block period. In some examples, the S-SSB manager 1315 may use a first beam set to transmit the second number of side link synchronization signal blocks. In some examples, the S-SSB manager 1315 may use a second beam set associated with a beam improvement procedure for one or more beams in the first beam set to transmit the first number of side link synchronization signal blocks. In some examples, the S-SSB manager 1315 may transmit to a second UE an indication that the second UE is to transmit a first number of side link synchronization signal blocks in a side link synchronization signal block period.

[0215] In some examples, the S-SSB manager 1315 may receive a first number of sidelink synchronization signal blocks transmitted using one or more beams as part of a beam improvement procedure based on transmitting the indication, each of the first number of sidelink synchronization signal blocks being transmitted using a different beam. In some examples, the S-SSB manager 1315 may receive the first number of sidelink synchronization signal blocks after a preconfigured time period after transmitting an indication that the first number of sidelink synchronization signal blocks are to be transmitted to the second UE. In some examples, the S-SSB manager 1315 may receive a second number of sidelink synchronization signal blocks based on failing to transmit an indication that the second UE is to transmit the first number of sidelink synchronization signal blocks in a sidelink synchronization signal block period. In some examples, the S-SSB manager 1315 may receive a second number of sidelink synchronization signal blocks transmitted using the first set of beams.

[0216] In some examples, the S-SSB manager 1315 may receive a first number of sidelink synchronization signal blocks transmitted using a second beam set associated with a beam perfection procedure for one or more beams in the first beam set. In some cases, the sidelink synchronization signal block shares the same synchronization grid as a downlink synchronization signal block in a shared spectrum. In some cases, the second starting resource block of the sidelink bandwidth portion includes an index of zero. In some cases, the sidelink synchronization signal block shares the same synchronization grid as a downlink synchronization signal block in a shared spectrum. In some cases, the index of the second starting resource block of the sidelink bandwidth portion is zero.

[0217] In some cases, the first synchronization grid of the sidelink synchronization signal block is different from the second synchronization grid of the downlink synchronization signal block in the shared spectrum. In some cases, the index of the same starting resource block of the sidelink synchronization signal block and the sidelink bandwidth part is zero. In some cases, the number of two or more sidelink synchronization signal blocks corresponds to the subcarrier spacing of the sidelink bandwidth part. In some cases, the number of two or more sidelink synchronization signal blocks in each sidelink synchronization signal block burst corresponds to the subcarrier spacing of the sidelink bandwidth part. In some cases, the indication of transmitting the first number of sidelink synchronization signal blocks is received in PRACH, sidelink control information or MAC-CE. In some cases, the indication of transmitting the first number of sidelink synchronization signal blocks is transmitted in PRACH, sidelink control information or MAC-CE.

[0218] The MIB manager 1320 may receive a master information block indicating an offset between a first starting resource block of a side link synchronization signal block and a second starting resource block of a side link bandwidth portion. In some examples, the MIB manager 1320 may transmit an indication of an offset between a first starting resource block of a side link synchronization signal block and a second starting resource block of a side link bandwidth portion in a master information block. The decoder 1325 may decode the side link synchronization signal block in the side link bandwidth portion based on receiving a master information block indicating the offset. In some examples, the decoder 1325 may blindly decode at least a portion of a demodulation reference signal scrambling sequence to identify a beam index of a beam used to transmit a side link synchronization signal block. In some examples, the decoder 1325 may blindly decode at least a portion of a demodulation reference signal scrambling sequence to identify a beam index of a beam used to transmit a side link synchronization signal block.

[0219] The S-SSB burst manager 1330 may identify a side link synchronization signal block burst to be transmitted in a side link synchronization signal block period, the side link synchronization signal block burst including two or more side link synchronization signal blocks. In some examples, the S-SSB burst manager 1330 may receive a side link synchronization signal block burst including two or more side link synchronization signal blocks in a contiguous time resource. In some examples, the S-SSB burst manager 1330 may identify a set of side link synchronization signal block bursts to be transmitted in a side link synchronization signal block period, each side link synchronization signal block burst including two or more side link synchronization signal blocks. In some examples, the S-SSB burst manager 1330 may receive the set of side link synchronization signal block bursts in a side link synchronization signal block period.

[0220] In some examples, the S-SSB burst manager 1330 may select a sidelink time interval for each sidelink synchronization signal block burst in the sidelink synchronization signal block burst set so that the sidelink synchronization signal block burst set is non-overlapping in a sidelink synchronization signal block period, wherein the sidelink time interval corresponds to a time interval between each of two or more sidelink synchronization signal blocks in each sidelink synchronization signal block burst. The beam manager 1335 may receive an indication of a preferred beam in the one or more beams for transmitting sidelink data to the second UE based on transmitting the one or more sidelink synchronization signal blocks. In some examples, the beam manager 1335 may select a preferred beam in the one or more beams for the second UE to use to transmit sidelink data to the first UE.

[0221] In some examples, the beam manager 1335 may transmit an indication of the preferred beam to the second UE based on the selection. In some examples, the beam manager 1335 may identify a beam for transmitting a sidelink synchronization signal block in two or more sidelink synchronization signal blocks. In some examples, the beam manager 1335 may identify a beam for transmitting a sidelink synchronization signal block in a sidelink synchronization signal block burst in the sidelink synchronization signal block burst set. In some examples, the beam manager 1335 may receive signaling on a PFSCH resource or a PRACH resource corresponding to a sidelink synchronization signal block transmitted using a preferred beam. In some examples, the beam manager 1335 may transmit signaling on a PFSCH resource or a PRACH resource corresponding to a sidelink synchronization signal block transmitted by the second UE using a preferred beam. In some cases, the indication of the preferred beam is received in a PSSCH. In some cases, the indication of the preferred beam is received in a PSSCH.

[0222] The DRS window manager 1350 may identify a DRS window in a shared spectrum that includes a set of starting positions for transmitting one or more side link synchronization signal blocks. In some examples, the DRS window manager 1350 may identify a DRS window in a shared spectrum in which one or more side link synchronization signal blocks are to be received. In some examples, it is determined that the discovery reference signal window includes a set of starting positions for receiving one or more side link synchronization signal blocks. The encoder 1340 may encode at least a portion of a demodulation reference signal scrambling sequence included with the side link synchronization signal block based on the beam index of the identified beam. In some examples, the encoder 1340 may set an initialization seed for encoding based on the beam index of the identified beam. In some examples, the encoder 1340 may encode at least a portion of a demodulation reference signal scrambling sequence included with the side link synchronization signal block based on the beam index of the identified beam. In some examples, the encoder 1340 may set an initialization seed for encoding based on the beam index of the identified beam.

[0223] The DMRS manager 1345 may receive a demodulation reference signal scrambling sequence together with a side link synchronization signal block in the two or more side link synchronization signal blocks. In some examples, the DMRS manager 1345 may receive a demodulation reference signal scrambling sequence together with a side link synchronization signal block in a side link synchronization signal block burst in the side link synchronization signal block burst set. The PBCH manager 1355 may generate a physical broadcast channel repetition by repeating the physical broadcast channel in the last codeword of the first side link synchronization signal block. The CP extension manager 1360 may generate a cyclic prefix extension based on the physical broadcast channel in the first codeword of the second side link synchronization signal block. The side link data manager 1365 may use a preferred beam to transmit side link data to the second UE. In some examples, the side link data manager 1365 may use a preferred beam to receive side link data from the second UE.

[0224] Fig.14 A diagram of a system 1400 including a device 1405 supporting S-SSB transmissions in a shared spectrum according to various aspects of the present disclosure is shown. The device 1405 may be an example of a device 1105, a device 1205, or a UE 115 as described herein or include components of these devices. The device 1405 may include components for two-way voice and data communications, including components for transmitting and receiving communications, including a communication manager 1410, an I / O controller 1415, a transceiver 1420, an antenna 1425, a memory 1430, and a processor 1440. These components may be in electronic communication via one or more buses (e.g., a bus 1445).

[0225] The communication manager 1410 can: perform a listen-before-talk procedure to obtain access to a side link bandwidth portion in a shared spectrum for side link communication; identify a side link synchronization signal block to be transmitted in the side link bandwidth portion; and transmit the side link synchronization signal block in the side link bandwidth portion so that a first starting resource block of the side link synchronization signal block is offset from a second starting resource block of the side link bandwidth portion.

[0226] The communication manager 1410 can also: identify a side link bandwidth portion in a shared spectrum that includes a side link synchronization signal block; receive a master information block indicating an offset between a first starting resource block of the side link synchronization signal block and a second starting resource block of the side link bandwidth portion; and decode the side link synchronization signal block in the side link bandwidth portion based on the received master information block indicating the offset.

[0227] The communication manager 1410 may also: perform a listen-before-talk procedure to gain access to a side link bandwidth portion in a shared spectrum for side link communications; identify a side link synchronization signal block to be transmitted in the side link bandwidth portion; and transmit the side link synchronization signal block in the side link bandwidth portion so that the side link synchronization signal block shares the same starting resource block as the side link bandwidth portion.

[0228] The communication manager 1410 may also: perform a listen-before-talk procedure to obtain access to a side link bandwidth portion in a shared spectrum for a side link synchronization signal block period; identify a side link synchronization signal block burst to be transmitted in the side link synchronization signal block period, the side link synchronization signal block burst comprising two or more side link synchronization signal blocks; and transmit each of the two or more side link synchronization signal blocks in the side link synchronization signal block burst using a different beam, wherein the two or more side link synchronization signal blocks in the side link synchronization signal block burst are transmitted in adjacent time resources.

[0229] The communication manager 1410 can also: identify a side link synchronization signal block period having a side link synchronization signal block burst including two or more side link synchronization signal blocks (each side link synchronization signal block is transmitted using a different beam); and receive a side link synchronization signal block burst including two or more side link synchronization signal blocks in adjacent time resources.

[0230] The communication manager 1410 may also: perform a listen-before-talk procedure to obtain access to a side link bandwidth portion in a shared spectrum for a side link synchronization signal block period; identify a set of side link synchronization signal block bursts to be transmitted in the side link synchronization signal block period, each side link synchronization signal block burst comprising two or more side link synchronization signal blocks; and transmit each of the two or more side link synchronization signal blocks in each side link synchronization signal block burst in the side link synchronization signal block period using a different beam.

[0231] The communication manager 1410 can also: identify a side link synchronization signal block period having a set of side link synchronization signal block bursts, each side link synchronization signal block burst including two or more side link synchronization signal blocks, and each of the two or more side link synchronization signal blocks is transmitted using a different beam; and receive the side link synchronization signal block burst set in the side link synchronization signal block period.

[0232] The communication manager 1410 can also: identify a DRS window in a shared spectrum that includes a set of starting positions for transmitting one or more side link synchronization signal blocks; perform a listen-before-talk procedure to gain access to a discovery reference signal window in the shared spectrum; and after gaining access to the discovery reference signal window in the shared spectrum, transmit one or more side link synchronization signal blocks at a first starting position in the set of starting positions.

[0233] The communication manager 1410 can also: identify a DRS window in a shared spectrum in which one or more side link synchronization signal blocks are to be received; determine that a reference signal window includes a set of starting positions for receiving one or more side link synchronization signal blocks; and monitor the set of starting positions to find one or more side link synchronization signal blocks in the reference signal window.

[0234] The communication manager 1410 can also: identify a first side link synchronization signal block to be transmitted in a first time slot and a second side link synchronization signal block to be transmitted in a second time slot in the side link bandwidth portion of the shared spectrum; generate a PBCH repetition or a cyclic prefix extension to fill a gap between the first side link synchronization signal block and the second side link synchronization signal block; and transmit the first side link synchronization signal block in the first time slot and the second side link synchronization signal block in the second time slot together with a physical broadcast channel repetition or cyclic prefix extension between the first side link synchronization signal block and the second side link synchronization signal block.

[0235] The communication manager 1410 may also: perform a listen-before-talk procedure to obtain access to a sidelink bandwidth portion in a shared spectrum for a sidelink synchronization signal block period; transmit one or more sidelink synchronization signal blocks using one or more beams in the sidelink synchronization signal block period, each of the one or more sidelink synchronization signal blocks being transmitted using a different beam; and receive, from a second UE based on transmitting the one or more sidelink synchronization signal blocks, an indication of a preferred beam of the one or more beams for transmitting sidelink data to the second UE.

[0236] The communication manager 1410 may also: receive one or more side link synchronization signal blocks transmitted using one or more beams from a second UE in a side link synchronization signal block period, each of the one or more side link synchronization signal blocks being transmitted using a different beam; select a preferred beam among the one or more beams for the second UE to use to transmit side link data to the first UE; and transmit an indication of the preferred beam to the second UE based on the selection.

[0237] The communication manager 1410 may also: execute a listen-before-talk procedure to obtain access to a side link bandwidth portion in a shared spectrum for a side link synchronization signal block period; determine whether a first number or a second number of side link synchronization signal blocks are to be transmitted in the side link synchronization signal block period, the first number being greater than the second number; and transmit the first number or the second number of side link synchronization signal blocks in the side link synchronization signal block period based on the determination.

[0238] The communication manager 1410 may also: determine whether to receive a first number or a second number of side link synchronization signal blocks from a second UE in a side link synchronization signal block period, the first number being greater than the second number; identify a side link synchronization signal block period having the first number or the second number of side link synchronization signal blocks; and receive the first number or the second number of side link synchronization signal blocks in the side link synchronization signal block period based on the determination.

[0239] I / O controller 1415 can manage input and output signals for device 1405. I / O controller 1415 can also manage peripheral devices that are not integrated into device 1405. In some cases, I / O controller 1415 can represent a physical connection or port to an external peripheral device. In some cases, I / O controller 1415 can utilize an operating system, such as or another known operating system. In other cases, I / O controller 1415 may represent or interact with a modem, keyboard, mouse, touch screen, or similar device. In some cases, I / O controller 1415 may be implemented as part of a processor. In some cases, a user may interact with device 1405 via I / O controller 1415 or via hardware components controlled by I / O controller 1415.

[0240] The transceiver 1420 may communicate bidirectionally via one or more antennas, wired or wireless links, as described above. For example, the transceiver 1420 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. The transceiver 1420 may also include a modem to modulate packets and provide the modulated packets to an antenna for transmission, and demodulate packets received from an antenna.

[0241] In some cases, a wireless device may include a single antenna 1425. However, in some cases, the device may have more than one antenna 1425, which may be capable of transmitting or receiving multiple wireless transmissions concurrently.

[0242] Memory 1430 may include RAM and ROM. Memory 1430 may store computer-readable, computer-executable code 1435 including instructions that, when executed, cause the processor to perform the various functions described herein. In some cases, memory 1430 may include, among other things, a BIOS that may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0243] Processor 1440 may include an intelligent hardware device (e.g., a general purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, processor 1440 may be configured to operate a memory array using a memory controller. In other cases, the memory controller may be integrated into processor 1440. Processor 1440 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 1430) to cause device 1405 to perform various functions (e.g., functions or tasks to support S-SSB transmission in a shared spectrum).

[0244] The code 1435 may include instructions for implementing various aspects of the present disclosure, including instructions for supporting wireless communications. The code 1435 may be stored in a non-transitory computer-readable medium, such as a system memory or other type of memory. In some cases, the code 1435 may not be directly executed by the processor 1440, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

[0245] Fig.15 1 is a flow chart illustrating a method 1500 for supporting S-SSB transmission in a shared spectrum according to aspects of the present disclosure. The operations of the method 1500 may be implemented by a UE 115 or components thereof as described herein. For example, the operations of the method 1500 may be implemented by a UE 115 or components thereof as described herein. Figures 11 to 14 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0246] At 1505, the UE may perform a listen-before-talk procedure to obtain access to a sidelink bandwidth portion of a shared spectrum for sidelink communications. The operations of 1505 may be performed according to the methods described herein. In some examples, aspects of the operations of 1505 may be performed as described with reference to Figures 11 to 14 The described LBT manager is used to perform

[0247] At 1510, the UE may identify a sidelink synchronization signal block to be transmitted in the sidelink bandwidth portion. The operations of 1510 may be performed according to the methods described herein. In some examples, aspects of the operations of 1510 may be performed as described with reference to Figures 11 to 14 The S-SSB manager described herein is used to perform the above operations.

[0248] At 1515, the UE may transmit the sidelink synchronization signal block in the sidelink bandwidth portion such that a first starting resource block of the sidelink synchronization signal block is offset from a second starting resource block of the sidelink bandwidth portion. The operations of 1515 may be performed according to the methods described herein. In some examples, aspects of the operations of 1515 may be performed as described with reference to Figures 11 to 14 The S-SSB manager described herein is used to perform the above operations.

[0249] Fig.16 1 is a flow chart illustrating a method 1600 for supporting S-SSB transmission in a shared spectrum according to aspects of the present disclosure. The operations of the method 1600 may be implemented by a UE 115 or components thereof as described herein. For example, the operations of the method 1600 may be implemented by a UE 115 or components thereof as described herein. Figures 11 to 14 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0250] At 1605, the UE may identify a sidelink bandwidth portion of the shared spectrum that includes a sidelink synchronization signal block. The operations of 1605 may be performed according to the methods described herein. In some examples, aspects of the operations of 1605 may be performed as described with reference to Figures 11 to 14The S-SSB manager described herein is used to perform the above operations.

[0251] At 1610, the UE may receive a master information block indicating an offset between a first starting resource block of a sidelink synchronization signal block and a second starting resource block of a sidelink bandwidth portion. The operations of 1610 may be performed according to the methods described herein. In some examples, aspects of the operations of 1610 may be performed as described with reference to Figures 11 to 14 The MIB manager described here is used to perform the

[0252] At 1615, the UE may decode the sidelink synchronization signal block in the sidelink bandwidth portion based on receiving the master information block indicating the offset. The operations of 1615 may be performed according to the methods described herein. In some examples, aspects of the operations of 1615 may be performed as described with reference to Figures 11 to 14 The decoder described is implemented.

[0253] Fig.17 1 is a flow chart illustrating a method 1700 for supporting S-SSB transmission in a shared spectrum according to aspects of the present disclosure. The operations of the method 1700 may be implemented by a UE 115 or components thereof as described herein. For example, the operations of the method 1700 may be implemented by a UE 115 or components thereof as described herein. Figures 11 to 14 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0254] At 1705, the UE may perform a listen-before-talk procedure to obtain access to a portion of the sidelink bandwidth in the shared spectrum for sidelink communications. The operations of 1705 may be performed according to the methods described herein. In some examples, aspects of the operations of 1705 may be performed as described with reference to Figures 11 to 14 The described LBT manager is used to perform

[0255] At 1710, the UE may identify a sidelink synchronization signal block to be transmitted in the sidelink bandwidth portion. The operations of 1710 may be performed according to the methods described herein. In some examples, aspects of the operations of 1710 may be performed as described with reference to Figures 11 to 14 The S-SSB manager described herein is used to perform the above operations.

[0256] At 1715, the UE may transmit a sidelink synchronization signal block in the sidelink bandwidth portion such that the sidelink synchronization signal block shares the same starting resource block as the sidelink bandwidth portion. The operations of 1715 may be performed according to the methods described herein. In some examples, aspects of the operations of 1715 may be performed as described with reference to Figures 11 to 14 The S-SSB manager described herein is used to perform the above operations.

[0257] Fig.18 A flow chart illustrating a method 1800 for supporting S-SSB transmission in a shared spectrum according to aspects of the present disclosure is shown. The operations of the method 1800 may be implemented by a UE 115 or components thereof as described herein. For example, the operations of the method 1800 may be implemented by a UE 115 or components thereof as described herein. Figures 11 to 14 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0258] At 1805, the UE may perform a listen-before-talk procedure to obtain access to the sidelink bandwidth portion in the shared spectrum for a sidelink synchronization signal block period. The operations of 1805 may be performed according to the methods described herein. In some examples, aspects of the operations of 1805 may be performed as described with reference to Figures 11 to 14 The described LBT manager is used to perform

[0259] At 1810, the UE may identify a sidelink synchronization signal block burst to be transmitted in a sidelink synchronization signal block period, the sidelink synchronization signal block burst comprising two or more sidelink synchronization signal blocks. The operations of 1810 may be performed according to the methods described herein. In some examples, aspects of the operations of 1810 may be performed as described with reference to Figures 11 to 14 The described S-SSB burst manager is implemented.

[0260] At 1815, the UE may transmit each of two or more sidelink synchronization signal blocks of a sidelink synchronization signal block burst using a different beam, wherein the two or more sidelink synchronization signal blocks in the sidelink synchronization signal block burst are transmitted in contiguous time resources. The operations of 1815 may be performed according to the methods described herein. In some examples, aspects of the operations of 1815 may be performed as described with reference to Figures 11 to 14 The S-SSB manager described herein is used to perform the above operations.

[0261] Fig.19 A flow chart illustrating a method 1900 for supporting S-SSB transmission in a shared spectrum according to aspects of the present disclosure is shown. The operations of the method 1900 may be implemented by a UE 115 or components thereof as described herein. For example, the operations of the method 1900 may be implemented by a UE 115 or components thereof as described herein. Figures 11 to 14 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0262] At 1905, the UE may identify a sidelink synchronization signal block period having a sidelink synchronization signal block burst including two or more sidelink synchronization signal blocks, each of which is transmitted using a different beam. The operations of 1905 may be performed according to the methods described herein. In some examples, aspects of the operations of 1905 may be performed as described with reference to Figures 11 to 14 The S-SSB manager described herein is used to perform the above operations.

[0263] At 1910, the UE may receive a sidelink synchronization signal block burst including two or more sidelink synchronization signal blocks in a contiguous time resource. The operations of 1910 may be performed according to the methods described herein. In some examples, aspects of the operations of 1910 may be performed as described with reference to Figures 11 to 14 The described S-SSB burst manager is implemented.

[0264] Fig. 20 1 is a flow chart illustrating a method 2000 for supporting S-SSB transmission in a shared spectrum according to aspects of the present disclosure. The operations of the method 2000 may be implemented by a UE 115 or components thereof as described herein. For example, the operations of the method 2000 may be implemented by a UE 115 or components thereof as described herein. Figures 11 to 14 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0265] At 2005, the UE may perform a listen-before-talk procedure to obtain access to the sidelink bandwidth portion in the shared spectrum for a sidelink synchronization signal block period. The operations of 2005 may be performed according to the methods described herein. In some examples, aspects of the operations of 2005 may be performed as described with reference to Figures 11 to 14 The described LBT manager is used to perform

[0266] At 2010, the UE may identify a set of sidelink synchronization signal block bursts to be transmitted in a sidelink synchronization signal block period, each sidelink synchronization signal block burst including two or more sidelink synchronization signal blocks. The operations of 2010 may be performed according to the methods described herein. In some examples, aspects of the operations of 2010 may be performed as described with reference to Figures 11 to 14 The described S-SSB burst manager is implemented.

[0267] At 2015, the UE may use different beams to transmit each of the two or more sidelink synchronization signal blocks in each sidelink synchronization signal block burst in the sidelink synchronization signal block period. The operations of 2015 may be performed according to the methods described herein. In some examples, various aspects of the operations of 2015 may be performed as described with reference to Figures 11 to 14The S-SSB manager described herein is used to perform the above operations.

[0268] Fig.21 1 is a flow chart illustrating a method 2100 for supporting S-SSB transmission in a shared spectrum according to aspects of the present disclosure. The operations of the method 2100 may be implemented by a UE 115 or components thereof as described herein. For example, the operations of the method 2100 may be implemented by a UE 115 or components thereof as described herein. Figures 11 to 14 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0269] At 2105, the UE may identify a sidelink synchronization signal block period having a set of sidelink synchronization signal block bursts, each sidelink synchronization signal block burst including two or more sidelink synchronization signal blocks, and each of the two or more sidelink synchronization signal blocks is transmitted using a different beam. The operations of 2105 may be performed according to the methods described herein. In some examples, aspects of the operations of 2105 may be performed as described with reference to Figures 11 to 14 The S-SSB manager described herein is used to perform the above operations.

[0270] At 2110, the UE may receive the sidelink synchronization signal block burst set in the sidelink synchronization signal block period. The operations of 2110 may be performed according to the methods described herein. In some examples, various aspects of the operations of 2110 may be performed as described with reference to Figures 11 to 14 The described S-SSB burst manager is implemented.

[0271] Fig. 22 1 is a flow chart illustrating a method 2200 for supporting S-SSB transmission in a shared spectrum according to aspects of the present disclosure. The operations of the method 2200 may be implemented by a UE 115 or components thereof as described herein. For example, the operations of the method 2200 may be implemented by a UE 115 or components thereof as described herein. Figures 11 to 14 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0272] At 2205, the UE may identify a discovery reference signal (DRS) window in the shared spectrum that includes a set of starting positions for transmitting one or more sidelink synchronization signal blocks. The operations of 2205 may be performed according to the methods described herein. In some examples, aspects of the operations of 2205 may be performed as described with reference to Figures 11 to 14 The DRS window manager described here is used to implement this.

[0273] At 2210, the UE may perform a listen-before-talk procedure to gain access to a discovery reference signal window in a shared spectrum. The operations of 2210 may be performed according to the methods described herein. In some examples, aspects of the operations of 2210 may be performed as described with reference to Figures 11 to 14 Description of the LBT manager to perform.

[0274] At 2215, the UE may transmit one or more sidelink synchronization signal blocks at a first starting position in the set of starting positions after obtaining access to the discovery reference signal window in the shared spectrum. The operations of 2215 may be performed according to the methods described herein. In some examples, aspects of the operations of 2215 may be performed as described with reference to Figures 11 to 14 The S-SSB manager described herein is used to perform the above operations.

[0275] Fig.23 1 is a flow chart illustrating a method 2300 for supporting S-SSB transmission in a shared spectrum according to aspects of the present disclosure. The operations of the method 2300 may be implemented by a UE 115 or components thereof as described herein. For example, the operations of the method 2300 may be implemented by a UE 115 or components thereof as described herein. Figures 11 to 14 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0276] At 2305, the UE may identify a discovery reference signal (DRS) window in the shared spectrum in which to receive one or more sidelink synchronization signal blocks. The operations of 2305 may be performed according to the methods described herein. In some examples, aspects of the operations of 2305 may be performed as described with reference to Figures 11 to 14 The DRS window manager described here is used to implement this.

[0277] At 2310, the UE may determine that the discovery reference signal window includes a set of starting positions for receiving one or more side link synchronization signal blocks. The operations of 2310 may be performed according to the methods described herein. In some examples, aspects of the operations of 2310 may be performed as described with reference to Figures 11 to 14 The DRS window manager described here is used to implement this.

[0278] At 2315, the UE may monitor the starting position set to find one or more side link synchronization signal blocks in the discovery reference signal window. The operations of 2315 may be performed according to the methods described herein. In some examples, aspects of the operations of 2315 may be performed as described with reference to Figures 11 to 14 The S-SSB manager described herein is used to perform the above operations.

[0279] Fig.24A flow chart illustrating a method 2400 for supporting S-SSB transmission in a shared spectrum according to aspects of the present disclosure is shown. The operations of the method 2400 may be implemented by a UE 115 or components thereof as described herein. For example, the operations of the method 2400 may be implemented by a UE 115 or components thereof as described herein. Figures 11 to 14 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0280] At 2405, the UE may identify a first sidelink synchronization signal block to be transmitted in a first time slot and a second sidelink synchronization signal block to be transmitted in a second time slot in a sidelink bandwidth portion of a shared spectrum. The operations of 2405 may be performed according to the methods described herein. In some examples, aspects of the operations of 2405 may be performed as described with reference to Figures 11 to 14 The S-SSB manager described herein is used to perform the above operations.

[0281] At 2410, the UE may generate a physical broadcast channel (PBCH) repetition or a cyclic prefix extension to fill a gap between a first side link synchronization signal block and a second side link synchronization signal block. The operations of 2410 may be performed according to the methods described herein. In some examples, aspects of the operations of 2410 may be performed as described with reference to Figures 11 to 14 The S-SSB manager described herein is used to perform the above operations.

[0282] At 2415, the UE may transmit a first side link synchronization signal block in a first time slot and a second side link synchronization signal block in a second time slot along with a physical broadcast channel repetition or cyclic prefix extension between the first side link synchronization signal block and the second side link synchronization signal block. The operations of 2415 may be performed according to the methods described herein. In some examples, aspects of the operations of 2415 may be performed as described with reference to Figures 11 to 14 The S-SSB manager described herein is used to perform the above operations.

[0283] Fig.25 A flow chart illustrating a method 2500 for supporting S-SSB transmission in a shared spectrum according to aspects of the present disclosure is shown. The operations of the method 2500 may be implemented by a UE 115 or components thereof as described herein. For example, the operations of the method 2500 may be implemented by a UE 115 or components thereof as described herein. Figures 11 to 14 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0284] At 2505, the UE may perform a listen-before-talk procedure to obtain access to the sidelink bandwidth portion in the shared spectrum for a sidelink synchronization signal block period. The operations of 2505 may be performed according to the methods described herein. In some examples, aspects of the operations of 2505 may be performed as described with reference to Figures 11 to 14 The described LBT manager is used to perform

[0285] At 2510, the UE may transmit one or more sidelink synchronization signal blocks using one or more beams in a sidelink synchronization signal block period, each of the one or more sidelink synchronization signal blocks being transmitted using a different beam. The operations of 2510 may be performed according to the methods described herein. In some examples, aspects of the operations of 2510 may be performed as described with reference to Figures 11 to 14 The S-SSB manager described herein is used to perform the above operations.

[0286] At 2515, the UE may receive, from a second UE, an indication of a preferred beam of the one or more beams for transmitting sidelink data to the second UE based on transmitting the one or more sidelink synchronization signal blocks. The operations of 2515 may be performed according to the methods described herein. In some examples, aspects of the operations of 2515 may be performed as described with reference to Figures 11 to 14 The beam manager described is implemented.

[0287] Fig.26 A flow chart illustrating a method 2600 for supporting S-SSB transmission in a shared spectrum according to aspects of the present disclosure is shown. The operations of the method 2600 may be implemented by a UE 115 or components thereof as described herein. For example, the operations of the method 2600 may be implemented by a UE 115 or components thereof as described herein. Figures 11 to 14 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0288] At 2605, the UE may receive one or more sidelink synchronization signal blocks transmitted using one or more beams from a second UE in a sidelink synchronization signal block period, each of the one or more sidelink synchronization signal blocks being transmitted using a different beam. The operations of 2605 may be performed according to the methods described herein. In some examples, aspects of the operations of 2605 may be performed as described with reference to Figures 11 to 14 The S-SSB manager described herein is used to perform the above operations.

[0289] At 2610, the UE may select a preferred beam from the one or more beams for the second UE to use to transmit sidelink data to the first UE. The operations of 2610 may be performed according to the methods described herein. In some examples, aspects of the operations of 2610 may be as described with reference to Figures 11 to 14 The beam manager described is implemented.

[0290] At 2615, the UE may transmit an indication of the preferred beam to the second UE based on the selection. The operations of 2615 may be performed according to the methods described herein. In some examples, aspects of the operations of 2615 may be as described with reference to Figures 11 to 14 The beam manager described is implemented.

[0291] Fig. 27 2700 for supporting S-SSB transmission in a shared spectrum according to aspects of the present disclosure. The operations of the method 2700 may be implemented by a UE 115 or components thereof as described herein. For example, the operations of the method 2700 may be implemented by a UE 115 or components thereof as described herein. Figures 11 to 14 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0292] At 2705, the UE may perform a listen-before-talk procedure to obtain access to the sidelink bandwidth portion in the shared spectrum for a sidelink synchronization signal block period. The operations of 2705 may be performed according to the methods described herein. In some examples, aspects of the operations of 2705 may be performed as described with reference to Figures 11 to 14 The described LBT manager is used to perform

[0293] At 2710, the UE may determine whether to transmit a first number or a second number of sidelink synchronization signal blocks in a sidelink synchronization signal block period, the first number being greater than the second number. The operations of 2710 may be performed according to the methods described herein. In some examples, aspects of the operations of 2710 may be performed as described with reference to Figures 11 to 14 The S-SSB manager described herein is used to perform the above operations.

[0294] At 2715, the UE may transmit a first number or a second number of sidelink synchronization signal blocks in a sidelink synchronization signal block period based on the determination. The operations of 2715 may be performed according to the methods described herein. In some examples, aspects of the operations of 2715 may be as described with reference to Figures 11 to 14 The S-SSB manager described herein is used to perform the above operations.

[0295] Fig.28 A flow chart illustrating a method 2800 for supporting S-SSB transmission in a shared spectrum according to aspects of the present disclosure is shown. The operations of the method 2800 may be implemented by a UE 115 or components thereof as described herein. For example, the operations of the method 2800 may be implemented by a UE 115 or components thereof as described herein. Figures 11 to 14In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0296] At 2805, the UE may determine whether to receive a first number or a second number of sidelink synchronization signal blocks from a second UE in a sidelink synchronization signal block period, the first number being greater than the second number. The operations of 2805 may be performed according to the methods described herein. In some examples, aspects of the operations of 2805 may be performed as described with reference to Figures 11 to 14 The S-SSB manager described herein is used to perform the above operations.

[0297] At 2810, the UE may identify a sidelink synchronization signal block period having a first number or a second number of sidelink synchronization signal blocks. The operations of 2810 may be performed according to the methods described herein. In some examples, aspects of the operations of 2810 may be performed as described with reference to Figures 11 to 14 The S-SSB manager described herein is used to perform the above operations.

[0298] At 2815, the UE may receive a first number or a second number of sidelink synchronization signal blocks in a sidelink synchronization signal block period based on the determination. The operations of 2815 may be performed according to the methods described herein. In some examples, aspects of the operations of 2815 may be as described with reference to Figures 11 to 14 The S-SSB manager described herein is used to perform the above operations.

[0299] It should be noted that the methods described herein describe possible implementations, and that the various operations and steps may be rearranged or otherwise modified and other implementations are possible. Furthermore, aspects from two or more methods may be combined.

[0300] Although aspects of LTE, LTE-A, LTE-A Pro, or NR systems may be described for example purposes, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in much of the description, the techniques described herein may also be applicable to networks other than LTE, LTE-A, LTE-A Pro, or NR networks. For example, the described techniques may be applied to various other wireless communication systems, such as Ultra Mobile Broadband (UMB), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, and other systems and radio technologies not explicitly mentioned herein.

[0301] The information and signals described herein may be represented using any of a variety of different techniques and technologies. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout this description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0302] The various illustrative blocks and components described in conjunction with the disclosure herein may be implemented or performed with a general purpose processor, a DSP, an ASIC, a CPU, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0303] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted by a computer-readable medium as one or more instructions or codes. Other examples and implementations fall within the scope of the present disclosure and the appended claims. For example, due to the nature of software, the functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or any combination thereof. Features that implement the functions may also be physically located in various locations, including being distributed so that parts of the functions are implemented at different physical locations.

[0304] Computer readable medium includes both non-transient computer storage medium and communication medium, and it includes any medium that facilitates computer program to transfer from one place to another place.Non-transient storage medium can be any available medium that can be accessed by general or special-purpose computer.As an example and not limitation, non-transient computer readable medium can include random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), flash memory, compact disk (CD) ROM or other optical disk storage, disk storage or other magnetic storage device, or can be used to carry or store instruction or data structure form of desired program code means and can be accessed by general or special-purpose computer or general or special-purpose processor any other non-transient medium.Similarly, any connection is also properly referred to as computer readable medium.For example, if software is transmitted from website, server or other remote source using coaxial cable, optical fiber cable, twisted pair, digital subscriber line (DSL) or wireless technology such as infrared, radio and microwave, then the coaxial cable, optical fiber cable, twisted pair, DSL or wireless technology such as infrared, radio and microwave are just included in the definition of computer readable medium. Disk and disc as used herein include CDs, laser discs, optical discs, digital versatile discs (DVDs), floppy disks, and Blu-ray discs, where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

[0305] As used herein (including in the claims), "or" used in a list of items (e.g., a list of items with a phrase such as "at least one of" or "one or more of") indicates an inclusive list, so that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Similarly, as used herein, the phrase "based on" should not be interpreted as referring to a closed set of conditions. For example, an example step described as "based on condition A" may be based on both condition A and condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "based at least in part on."

[0306] In the accompanying drawings, similar components or features may have the same reference number. In addition, various components of the same type may be distinguished by following the reference number with a dash and a second reference number that distinguishes between similar components. If only the first reference number is used in the specification, the description may apply to any of the similar components having the same first reference number regardless of the second reference number, or other subsequent reference numbers.

[0307] The descriptions set forth herein in conjunction with the accompanying drawings describe example configurations and do not represent all examples that can be implemented or fall within the scope of the claims. The term "example" as used herein means "used as an example, instance, or illustration" and does not mean "better than" or "better than other examples." This detailed description includes specific details to provide an understanding of the described techniques. However, these techniques may be practiced without these specific details. In some instances, known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described examples.

[0308] The description herein is provided to enable one of ordinary skill in the art to make or use the present disclosure. Various modifications to the present disclosure will be apparent to one of ordinary skill in the art, and the universal principles defined herein may be applied to other variations without departing from the scope of the present disclosure. Thus, the present disclosure is not limited to the examples and designs described herein, but should be granted the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for wireless communication at a user equipment (UE), comprising: performing a listen-before-talk procedure to obtain access to a sidelink bandwidth portion in a shared spectrum for a sidelink synchronization signal block period; identifying a sidelink synchronization signal block burst to be transmitted in the sidelink synchronization signal block period, the sidelink synchronization signal block burst comprising two or more sidelink synchronization signal blocks; as well as Each of the two or more sidelink synchronization signal blocks of the sidelink synchronization signal block burst is transmitted using a different beam, wherein the two or more sidelink synchronization signal blocks in the sidelink synchronization signal block burst are transmitted in contiguous time resources.

2. The method of claim 1, further comprising: identifying a beam for transmitting a sidelink synchronization signal block of the two or more sidelink synchronization signal blocks; as well as At least a portion of a demodulation reference signal scrambling sequence included with the sidelink synchronization signal block is encoded based at least in part on a beam index of the identified beam.

3. The method of claim 2, wherein: Encoding the at least a portion of the demodulation reference signal comprises: An initialization seed for the encoding is set according to a beam index of the identified beam.

4. The method of claim 1, wherein: The number of the two or more sidelink synchronization signal blocks corresponds to the subcarrier spacing of the sidelink bandwidth portion.

5. The method of claim 1, wherein: Implementation of the listen-before-talk protocol includes: A class two listen-before-talk procedure is performed to obtain access to the sidelink bandwidth portion in the shared spectrum for the sidelink synchronization signal block period.

6. The method of claim 1, wherein: Implementation of the listen-before-talk protocol includes: A category four listen-before-talk procedure is performed to obtain access to the sidelink bandwidth portion in the shared spectrum for the sidelink synchronization signal block period.

7. The method of claim 1, wherein: Implementation of the listen-before-talk protocol includes: A class two or class four listen-before-talk procedure using a highest available priority associated therewith is performed to gain access to the sidelink bandwidth portion in the shared spectrum for the sidelink synchronization signal block period.

8. A method for wireless communication at a user equipment (UE), comprising: performing a listen-before-talk procedure to obtain access to a sidelink bandwidth portion in a shared spectrum for a sidelink synchronization signal block period; identifying a plurality of sidelink synchronization signal block bursts to be transmitted in the sidelink synchronization signal block period, each sidelink synchronization signal block burst comprising two or more sidelink synchronization signal blocks; as well as Each of the two or more sidelink synchronization signal blocks in each sidelink synchronization signal block burst is transmitted using a different beam in the sidelink synchronization signal block period.

9. The method of claim 8, further comprising: A side link time interval for each of the multiple side link synchronization signal block bursts is selected so that the multiple side link synchronization signal block bursts are non-overlapping in the side link synchronization signal block period, wherein the side link time interval corresponds to a time interval between each of two or more side link synchronization signal blocks in each side link synchronization signal block burst.

10. The method of claim 8, further comprising: identifying a beam for transmitting a sidelink synchronization signal block in a sidelink synchronization signal block burst in the plurality of sidelink synchronization signal block bursts; as well as At least a portion of a demodulation reference signal scrambling sequence included with the sidelink synchronization signal block is encoded based at least in part on a beam index of the identified beam.

11. The method of claim 10, wherein: Encoding the at least a portion of the demodulation reference signal comprises: An initialization seed for the encoding is set according to a beam index of the identified beam.

12. The method of claim 8, wherein: The number of two or more sidelink synchronization signal blocks in each sidelink synchronization signal block burst corresponds to the subcarrier spacing of the sidelink bandwidth portion.

13. The method of claim 8, wherein: Implementation of the listen-before-talk protocol includes: A class two listen-before-talk procedure is performed to obtain access to the sidelink bandwidth portion in the shared spectrum for the sidelink synchronization signal block period.

14. The method of claim 8, wherein: Implementation of the listen-before-talk protocol includes: A category four listen-before-talk procedure is performed to obtain access to the sidelink bandwidth portion in the shared spectrum for the sidelink synchronization signal block period.

15. The method of claim 8, wherein: Implementation of the listen-before-talk protocol includes: A class two or class four listen-before-talk procedure using a highest available priority associated therewith is performed to gain access to the sidelink bandwidth portion in the shared spectrum for the sidelink synchronization signal block period.

16. An apparatus for wireless communication at a user equipment (UE), comprising: processor, and a memory coupled to the processor, wherein the memory includes instructions executable by the processor to cause the apparatus to: performing a listen-before-talk procedure to obtain access to a sidelink bandwidth portion in a shared spectrum for a sidelink synchronization signal block period; identifying a sidelink synchronization signal block burst to be transmitted in the sidelink synchronization signal block period, the sidelink synchronization signal block burst comprising two or more sidelink synchronization signal blocks; as well as Each of the two or more sidelink synchronization signal blocks of the sidelink synchronization signal block burst is transmitted using a different beam, wherein the two or more sidelink synchronization signal blocks in the sidelink synchronization signal block burst are transmitted in contiguous time resources.

17. The device of claim 16, wherein: The instructions are further executable by the processor to cause the device to: identifying a beam for transmitting a sidelink synchronization signal block of the two or more sidelink synchronization signal blocks; and At least a portion of a demodulation reference signal scrambling sequence included with the sidelink synchronization signal block is encoded based at least in part on a beam index of the identified beam.

18. The device of claim 17, wherein: The instructions for encoding the at least a portion of the demodulation reference signal are executable by the processor to cause the apparatus to: An initialization seed for the encoding is set according to a beam index of the identified beam.

19. The device of claim 16, wherein: The number of the two or more sidelink synchronization signal blocks corresponds to the subcarrier spacing of the sidelink bandwidth portion.

20. The device of claim 16, wherein: The instructions for executing the listen-before-talk procedure are executable by the processor to cause the apparatus to: A class two listen-before-talk procedure is performed to obtain access to the sidelink bandwidth portion in the shared spectrum for the sidelink synchronization signal block period.

21. The apparatus of claim 16, wherein: The instructions for executing the listen-before-talk procedure are executable by the processor to cause the apparatus to: A category four listen-before-talk procedure is performed to obtain access to the sidelink bandwidth portion in the shared spectrum for the sidelink synchronization signal block period.

22. The apparatus of claim 16, wherein: The instructions for executing the listen-before-talk procedure are executable by the processor to cause the apparatus to: A class two or class four listen-before-talk procedure using a highest available priority associated therewith is performed to gain access to the sidelink bandwidth portion in the shared spectrum for the sidelink synchronization signal block period.

23. An apparatus for wireless communication at a user equipment (UE), comprising: processor, and a memory coupled to the processor, wherein the memory includes instructions executable by the processor to cause the apparatus to: performing a listen-before-talk procedure to obtain access to a sidelink bandwidth portion in a shared spectrum for a sidelink synchronization signal block period; identifying a plurality of sidelink synchronization signal block bursts to be transmitted in the sidelink synchronization signal block period, each sidelink synchronization signal block burst comprising two or more sidelink synchronization signal blocks; as well as Each of the two or more sidelink synchronization signal blocks in each sidelink synchronization signal block burst is transmitted using a different beam in the sidelink synchronization signal block period.

24. The device of claim 23, wherein: The instructions are further executable by the processor to cause the device to: A side link time interval for each of the multiple side link synchronization signal block bursts is selected so that the multiple side link synchronization signal block bursts are non-overlapping in the side link synchronization signal block period, wherein the side link time interval corresponds to a time interval between each of two or more side link synchronization signal blocks in each side link synchronization signal block burst.

25. The apparatus of claim 23, wherein: The instructions are further executable by the processor to cause the device to: identifying a beam for transmitting a sidelink synchronization signal block in a sidelink synchronization signal block burst in the plurality of sidelink synchronization signal block bursts; and At least a portion of a demodulation reference signal scrambling sequence included with the sidelink synchronization signal block is encoded based at least in part on a beam index of the identified beam.

26. The device of claim 25, wherein: The instructions for encoding the at least a portion of the demodulation reference signal are executable by the processor to cause the apparatus to: An initialization seed for the encoding is set according to a beam index of the identified beam.

27. The apparatus of claim 23, wherein: The number of two or more sidelink synchronization signal blocks in each sidelink synchronization signal block burst corresponds to the subcarrier spacing of the sidelink bandwidth portion.

28. The apparatus of claim 23, wherein: The instructions for executing the listen-before-talk procedure are executable by the processor to cause the apparatus to: A class two listen-before-talk procedure is performed to obtain access to the sidelink bandwidth portion in the shared spectrum for the sidelink synchronization signal block period.

29. The apparatus of claim 23, wherein: The instructions for executing the listen-before-talk procedure are executable by the processor to cause the apparatus to: A category four listen-before-talk procedure is performed to obtain access to the sidelink bandwidth portion in the shared spectrum for the sidelink synchronization signal block period.

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