WO2025025132A1

WO2025025132A1 - Sidelink synchronization signal block (s-ssb) communication in multiple resource block sets

Info

Publication number: WO2025025132A1
Application number: PCT/CN2023/110488
Authority: WO
Inventors: Siyi Chen; Jing Sun; Xiaoxia Zhang; Chih-Hao Liu; Giovanni Chisci; Changlong Xu; Shaozhen GUO; Luanxia YANG; Hao Xu
Original assignee: Qualcomm Inc
Current assignee: Qualcomm Inc
Priority date: 2023-08-01
Filing date: 2023-08-01
Publication date: 2025-02-06
Anticipated expiration: 2026-02-01

Abstract

Certain aspects of the present disclosure provide techniques for wireless communications by an apparatus. A method includes receiving an indication of a reference number of times to transmit sidelink synchronization signal block (S-SSB) in a sidelink bandwidth part (SL-BWP); and transmitting, in each of a plurality of resource block (RB) sets, a first S-SSB using a first transmit power, wherein the first transmit power is based on the reference number of times to transmit S-SSB.

Description

SIDELINK SYNCHRONIZATION SIGNAL BLOCK (S-SSB) COMMUNICATION IN MULTIPLE RESOURCE BLOCK SETS

INTRODUCTION

Field of the Disclosure

Aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for communication of sidelink synchronization signal blocks.

Description of Related Art

Wireless communications systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, broadcasts, or other similar types of services. These wireless communications systems may employ multiple-access technologies capable of supporting communications with multiple users by sharing available wireless communications system resources with those users

Although wireless communications systems have made great technological advancements over many years, challenges still exist. For example, complex and dynamic environments can still attenuate or block signals between wireless transmitters and wireless receivers. Accordingly, there is a continuous desire to improve the technical performance of wireless communications systems, including, for example: improving speed and data carrying capacity of communications, improving efficiency of the use of shared communications mediums, reducing power used by transmitters and receivers while performing communications, improving reliability of wireless communications, avoiding redundant transmissions and/or receptions and related processing, improving the coverage area of wireless communications, increasing the number and types of devices that can access wireless communications systems, increasing the ability for different types of devices to intercommunicate, increasing the number and type of wireless communications mediums available for use, and the like. Consequently, there exists a need for further improvements in wireless communications systems to overcome the aforementioned technical challenges and others.

SUMMARY

One aspect provides a method for wireless communications by an apparatus. The method includes receiving an indication of a reference number of times to transmit sidelink synchronization signal block (S-SSB) in a sidelink bandwidth part (SL-BWP) ; and transmitting, in each of a plurality of resource block (RB) sets, a first S-SSB using a first transmit power, wherein the first transmit power is based on the reference number of times to transmit S-SSB.

Another aspect provides a method for wireless communications by an apparatus. The method includes receiving physical sidelink broadcast channel (PSBCH) including demodulation reference signal (DMRS) in an anchor RB set of a SL-BWP comprising a plurality of RB sets, the DMRS carrying one or more bits that identify one or more RB sets of the plurality of RB sets as including a first S-SSB; and receiving the first S-SSB in each of the one or more RB sets.

Other aspects provide: one or more apparatuses operable, configured, or otherwise adapted to perform any portion of any method described herein (e.g., such that performance may be by only one apparatus or in a distributed fashion across multiple apparatuses) ; one or more non-transitory, computer-readable media comprising instructions that, when executed by one or more processors of one or more apparatuses, cause the one or more apparatuses to perform any portion of any method described herein (e.g., such that instructions may be included in only one computer-readable medium or in a distributed fashion across multiple computer-readable media, such that instructions may be executed by only one processor or by multiple processors in a distributed fashion, such that each apparatus of the one or more apparatuses may include one processor or multiple processors, and/or such that performance may be by only one apparatus or in a distributed fashion across multiple apparatuses) ; one or more computer program products embodied on one or more computer-readable storage media comprising code for performing any portion of any method described herein (e.g., such that code may be stored in only one computer-readable medium or across computer-readable media in a distributed fashion) ; and/or one or more apparatuses comprising one or more means for performing any portion of any method described herein (e.g., such that performance would be by only one apparatus or by multiple apparatuses in a distributed fashion) . By way of example, an apparatus may comprise a processing system, a device with a processing system, or processing systems cooperating over one or more networks.

The following description and the appended figures set forth certain features for purposes of illustration.

BRIEF DESCRIPTION OF DRAWINGS

The appended figures depict certain features of the various aspects described herein and are not to be considered limiting of the scope of this disclosure.

FIG. 1 depicts an example wireless communications network.

FIG. 2 depicts an example disaggregated base station architecture.

FIG. 3 depicts aspects of an example base station and an example user equipment (UE) .

FIGS. 4A, 4B, 4C, and 4D depict various example aspects of data structures for a wireless communications network.

FIG. 5 illustrates an example of communication of a sidelink synchronization signal block (S-SSB) in each of a plurality of resource block (RB) sets of a sidelink bandwidth part (SL-BWP) .

FIG. 6 illustrates an example of communication of an S-SSB in each of a plurality of RB sets of an SL-BWP.

FIG. 7 illustrates an example of communication of an S-SSB in each of a plurality of RB sets of an SL-BWP.

FIG. 8 illustrates an example of communication of an S-SSB in each of a plurality of RB sets of an SL-BWP.

FIG. 9 depicts a method for wireless communications.

FIG. 10 depicts another method for wireless communications.

FIG. 11 depicts aspects of an example communications device.

FIG. 12 depicts aspects of an example communications device.

DETAILED DESCRIPTION

Aspects of the present disclosure provide apparatuses, methods, processing systems, and computer-readable mediums for sidelink synchronization signal block (S-SSB) communication.

Certain wireless communications devices (e.g., user equipments (UEs) , base stations (BSs) , other network entities, etc. ) may be capable of communicating in unlicensed frequency spectrum (also referred to as shared spectrum) , such as on one or more unlicensed frequency bands (referred to as unlicensed bands or unlicensed channels) . For example, the unlicensed frequency spectrum may be divided into one or more unlicensed bands (also referred to as bandwidth parts (BWPs) ) , such as having a bandwidth of 20 MHz each. In some cases, wireless communications devices may communicate with participation of a base station, such as based on 5G New Radio Unlicensed (NR-U) mode of operation, or directly without participation of a base station, such as based on sidelink on unlicensed band (SL-U) mode of operation. Unlicensed spectrum refers to a part of the electromagnetic spectrum that can be assigned or shared by devices for non-exclusive usage, while licensed spectrum is a part of the electromagnetic spectrum assigned exclusively to mobile network operators.

In unlicensed spectrum, channel access is not guaranteed, meaning access to an unlicensed frequency band is not guaranteed. Thus, to provision for (e.g., sidelink) services over unlicensed spectrum, wireless communications devices are required to contend for channel access in the spectrum, for example, via clear channel assessment (CCA) and/or listen-before-talk (LBT) procedures.

For example, before transmitting on one or more unlicensed bands, the wireless communications device may perform LBT on the one or more unlicensed bands to ensure the one or more unlicensed bands are idle (not in use by another wireless communications device) . Accordingly, each unlicensed band may also be referred to as an LBT band. The LBT procedure helps avoid interference between devices. An LBT can be based on energy detection (ED) or signal detection. For an energy detection-based LBT, the LBT results in a pass (meaning the unlicensed band is idle) when signal energy measured from the channel (e.g., unlicensed band) is below a threshold. Conversely, the LBT results in a failure (meaning the unlicensed band is occupied) when signal energy measured from the channel exceeds the threshold. For a signal detection-based LBT, the LBT results in a pass when a channel reservation signal (e.g., a predetermined preamble signal) is not detected in the channel.

When the LBT results in a pass for an unlicensed band, the wireless communications device is able to transmit on the unlicensed band. In particular, when the LBT results in a pass, the wireless communications device acquires a channel occupancy time (COT) in the unlicensed band. A COT is a duration during which the wireless communications device can transmit in the unlicensed band. In particular, the COT indicates an amount of time, such as a maximum amount of time, a device may occupy a channel (the unlicensed band) for a given transmission burst. For example, the COT may be 4 ms or 10 ms, depending on the region.

In certain aspects, to reserve the COT in the unlicensed band, at least one wireless communications device transmits at least one signal in at least a portion of the unlicensed band. For example, the frequency range of unlicensed band may be divided into a number of subcarriers, each subcarrier corresponding to a portion of the overall frequency range of the unlicensed band. Accordingly, to reserve the COT, at least one wireless communications device transmits at least one signal in one or more subcarriers of the unlicensed band, such as in one or more resource blocks (RBs) , where an RB includes a plurality of consecutive in frequency subcarriers. Consecutive in frequency subcarriers means there are no other subcarriers in between the subcarriers of the RB in frequency.

In certain aspects, for sidelink communication, such as for wireless communications devices operating in an SL-U mode of operation, the unlicensed band that the wireless communications devices communicate in is referred to as a sidelink BWP (SL-BWP) . The SL-BWP may include multiple RB sets, where each RB set includes a plurality of consecutive in frequency RBs. Consecutive in frequency RBs means there are no other RBs in between the RBs of the RB set in frequency. In certain aspects, the multiple RB sets of the SL-BWP are contiguous in frequency. In certain aspects, a device may use only a portion of the RB sets of the multiple RB sets of the SL-BWP for communication (e.g., for transmitting S-SSB and/or PSFCH) , where the portion of the RB sets are non-contiguous in frequency.

When performing sidelink communication, quality of service (QoS) and system performance may be affected by timing misalignments between wireless communications devices. Therefore, to maintain a common synchronization of time and frequency among the wireless communications devices, each of the wireless communications devices may be synchronized either to a synchronization source, such as a base station or global navigation satellite system (GNSS) , or based on a time/frequency reference within a wireless communications device. One or more wireless communications devices may further generate and transmit synchronization information for use by other wireless communications devices in synchronizing the radio frame timing (e.g., radio frame/slot boundaries and frame index) to the transmitting wireless communications device. For example, the synchronization information may include a sidelink synchronization signal (S-SS) . In some examples, the S-SS may be part of an S-SSB, which includes a sidelink primary synchronization signal (S-PSS) , sidelink secondary synchronization signal (S-SSS) , and a physical sidelink broadcast channel (PSBCH) . The S-SSB may further include a downlink modulation reference signal (DMRS) , such as in the PSBCH, or other signals used for synchronization.

In certain aspects, a wireless communications device, such as a UE, may transmit an S-SSB in a plurality of RB sets of a SL-BWP, such as to reserve a COT in each of the plurality of RB sets. In certain aspects, the wireless communications device transmits the same S-SSB in each of the plurality of RB sets, meaning the same information is transmitted as an S-SSB in each of the plurality of RB sets. The transmission of the same S-SSB in each of the plurality of RB sets may be referred to as transmission of S-SSB repetitions in each of the plurality of RB sets, where an S-SSB repetition refers to an instance of the S-SSB, such as transmitted in an RB set.

In certain aspects, multiple wireless communications devices may transmit S-SSBs in an SL-BWP, and a receiving wireless communications device, such as a UE, may measure the DMRS in the PSBCH of S-SSBs to determine which of the multiple wireless communications devices the receiving wireless communications device should select as a synchronization reference device (e.g., SyncRef UE) . A synchronization reference device may be the wireless communications device to which the receiving wireless communications device synchronizes its radio frame timing.

In particular, each S-SSB indicates a sidelink synchronization signal (SLSS) identifier (ID) , which may be indicated by the sequences included in the S-PSS and S-SSS of the S-SSB. The SLSS ID represents an identifier of the wireless communications device that transmitted the S-SSB and conveys a priority of the wireless communications device. The receiving wireless communications device measures the DMRS in the PSBCH of each S-SSB (e.g., measures reference signal received power (RSRP) of the DMRS) transmitted by the multiple wireless communications devices. Accordingly, the receiving wireless communications device measures an RSRP for each S-SSB. Each S-SSB with an RSRP that is above a threshold (e.g., a threshold configured at the wireless communications device using radio resource control (RRC) signaling) is considered a candidate synchronization reference of the receiving wireless communications device. As discussed, each S-SSB is further associated with an SLSS ID, which is associated with a priority. Thus, each S-SSB is associated with a priority.

Where only one S-SSB of the S-SSB (s) of the candidate synchronization reference (s) of the receiving wireless communications device has a highest priority among the candidate synchronization reference (s) , the wireless communications device (e.g., as identified by the SLSS ID) that transmitted the one S-SSB is selected by the receiving wireless communications device to be the synchronization reference device for the receiving wireless communications device.

Where multiple S-SSBs of the S-SSBs of the candidate synchronization references of the receiving wireless communications device have the same and highest priority among the candidate synchronization references, the wireless communications device that transmitted the S-SSB with the highest RSRP among the multiple S-SSBs is selected by the receiving wireless communications device to be the synchronization reference device for the receiving wireless communications device.

Accordingly, the RSRP associated with an S-SSB is important for determining a synchronization reference device for a receiving wireless communications device. The RSRP associated with an S-SSB is impacted by the transmission power with which the S-SSB is transmitted. In particular, when a higher transmission power is used by a wireless communications device to transmit an S-SSB, a receiving wireless communications device will likely receive the S-SSB with a higher power, leading to a higher measured RSRP. Therefore, the power level at which an S-SSB is transmitted is important.

As discussed, in certain aspects, a wireless communications device, such as a UE, may transmit an S-SSB in a plurality of RB sets of a SL-BWP, such as to reserve a COT in each of the plurality of RB sets. Further, a wireless communications device may have certain power constraints for transmission. Therefore, the transmission power used to transmit an S-SSB in each RB set of the plurality of RB sets may be subject to power constraints, but also may be important for selection of a synchronization reference device. Accordingly, there is a technical problem of how to determine a power level with which to transmit S-SSB in a plurality of RB sets of an SL-BWP.

Certain aspects provide a parameter referred to as a reference number of times (K) to transmit S-SSB in an SL-BWP, where the transmit power used to transmit the S- SSB in each RB set of a plurality of RB sets of the SL-BWP is based on K. In certain aspects, the actual number of times a wireless communications device transmits S-SSB is equal to K, such as where the wireless communications device transmits S-SSB in K RB sets. In certain aspects, the actual number of times a wireless communications device transmits S-SSB is greater than K, such as where the wireless communications device transmits S-SSB in more than K RB sets. Using the parameter K to determine a transmit power used to transmit the S-SSB in each RB set of a plurality of RB sets of the SL-BWP provides the technical effect of ensuring the wireless communications device abides by power constraints for transmission, while providing higher transmit power when feasible for S-SSB transmission, which assists in appropriate selection of a synchronization reference device, as discussed herein. This allows increased S-SSB coverage as well.

In certain aspects, where the same S-SSB is transmitted on a plurality of RB sets by a wireless communications device, one of the RB sets may be an anchor RB set of the plurality of RB sets. In certain aspects, the anchor RB set is identified by an information element (e.g., sl-AbsoluteFrequencySSB-r16) , such as in RRC signaling, such as to a receiving wireless communications device. In certain aspects, a receiving wireless communications device is configured to only measure DMRS in PSBCH of the S-SSB communicated in the anchor RB set, and not the other RB sets of the plurality of RB sets, and therefore use the anchor RB set to determine a synchronization reference device. However, in certain aspects, the receiving wireless communications device may combine the S-SSBs received in each of the RB sets of the plurality of RB sets so as to enhance the decoding of the S-SSB. In order to combine the S-SSBs received in each of the RB sets of the plurality of RB sets, the receiving wireless communications device may need information as to which RB sets of the SL-BWP include the S-SSB other than the anchor RB set, as in the receiving wireless communications device may need information on each RB set of the SL-BWP included in the plurality of RB sets used by the wireless communications device to transmit the S-SSB. Accordingly, there is a technical problem of how to identify which RB sets of the SL-BWP include the S-SSB.

Certain aspects provide one or more bits in the DMRS in the PSBCH of the S-SSB communicated in the anchor RB set, where the one or more bits indicate which RB sets of the SL-BWP include the S-SSB. For example, the one or more bits may be scrambled in the DMRS. Providing the one or more bits provides the technical effect of providing the receiving wireless communications device an indication of where repetitions of the S-SSB are communicated, such that the receiving wireless communications device can combine the repetitions of the S-SSB to improve decoding performance.

Introduction to Wireless Communications Networks

The techniques and methods described herein may be used for various wireless communications networks. While aspects may be described herein using terminology commonly associated with 3G, 4G, and/or 5G wireless technologies, aspects of the present disclosure may likewise be applicable to other communications systems and standards not explicitly mentioned herein.

FIG. 1 depicts an example of a wireless communications network 100, in which aspects described herein may be implemented.

Generally, wireless communications network 100 includes various network entities (alternatively, network elements or network nodes) . A network entity is generally a communications device and/or a communications function performed by a communications device (e.g., a user equipment (UE) , a base station (BS) , a component of a BS, a server, etc. ) . As such communications devices are part of wireless communications network 100, and facilitate wireless communications, such communications devices may be referred to as wireless communications devices. For example, various functions of a network as well as various devices associated with and interacting with a network may be considered network entities. Further, wireless communications network 100 includes terrestrial aspects, such as ground-based network entities (e.g., BSs 102) , and non-terrestrial aspects, such as satellite 140 and aircraft 145, which may include network entities on-board (e.g., one or more BSs) capable of communicating with other network elements (e.g., terrestrial BSs) and UEs.

In the depicted example, wireless communications network 100 includes BSs 102, UEs 104, and one or more core networks, such as an Evolved Packet Core (EPC) 160 and 5G Core (5GC) network 190, which interoperate to provide communications services over various communications links, including wired and wireless links.

FIG. 1 depicts various example UEs 104, which may more generally include: a cellular phone, smart phone, session initiation protocol (SIP) phone, laptop, personal digital assistant (PDA) , satellite radio, global positioning system, multimedia device, video device, digital audio player, camera, game console, tablet, smart device, wearable device, vehicle, electric meter, gas pump, large or small kitchen appliance, healthcare device, implant, sensor/actuator, display, internet of things (IoT) devices, always on (AON) devices, edge processing devices, or other similar devices. UEs 104 may also be referred to more generally as a mobile device, a wireless device, a station, a mobile station, a subscriber station, a mobile subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a remote device, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, and others.

BSs 102 wirelessly communicate with (e.g., transmit signals to or receive signals from) UEs 104 via communications links 120. The communications links 120 between BSs 102 and UEs 104 may include uplink (UL) (also referred to as reverse link) transmissions from a UE 104 to a BS 102 and/or downlink (DL) (also referred to as forward link) transmissions from a BS 102 to a UE 104. The communications links 120 may use multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity in various aspects.

BSs 102 may generally include: a NodeB, enhanced NodeB (eNB) , next generation enhanced NodeB (ng-eNB) , next generation NodeB (gNB or gNodeB) , access point, base transceiver station, radio base station, radio transceiver, transceiver function, transmission reception point, and/or others. Each of BSs 102 may provide communications coverage for a respective coverage area 110, which may sometimes be referred to as a cell, and which may overlap in some cases (e.g., small cell 102’ may have a coverage area 110’ that overlaps the coverage area 110 of a macro cell) . A BS may, for example, provide communications coverage for a macro cell (covering relatively large geographic area) , a pico cell (covering relatively smaller geographic area, such as a sports stadium) , a femto cell (relatively smaller geographic area (e.g., a home) ) , and/or other types of cells.

While BSs 102 are depicted in various aspects as unitary communications devices, BSs 102 may be implemented in various configurations. For example, one or more components of a base station may be disaggregated, including a central unit (CU) , one or more distributed units (DUs) , one or more radio units (RUs) , a Near-Real Time (Near-RT) RAN Intelligent Controller (RIC) , or a Non-Real Time (Non-RT) RIC, to name a few examples. In another example, various aspects of a base station may be virtualized. More generally, a base station (e.g., BS 102) may include components that are located at a single physical location or components located at various physical locations. In examples in which a base station includes components that are located at various physical locations, the various components may each perform functions such that, collectively, the various components achieve functionality that is similar to a base station that is located at a single physical location. In some aspects, a base station including components that are located at various physical locations may be referred to as a disaggregated radio access network architecture, such as an Open RAN (O-RAN) or Virtualized RAN (VRAN) architecture. FIG. 2 depicts and describes an example disaggregated base station architecture.

Different BSs 102 within wireless communications network 100 may also be configured to support different radio access technologies, such as 3G, 4G, and/or 5G. For example, BSs 102 configured for 4G LTE (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN) ) may interface with the EPC 160 through first backhaul links 132 (e.g., an S1 interface) . BSs 102 configured for 5G (e.g., 5G NR or Next Generation RAN (NG-RAN) ) may interface with 5GC 190 through second backhaul links 184. BSs 102 may communicate directly or indirectly (e.g., through the EPC 160 or 5GC 190) with each other over third backhaul links 134 (e.g., X2 interface) , which may be wired or wireless.

Wireless communications network 100 may subdivide the electromagnetic spectrum into various classes, bands, channels, or other features. In some aspects, the subdivision is provided based on wavelength and frequency, where frequency may also be referred to as a carrier, a subcarrier, a frequency channel, a tone, or a subband. For example, 3GPP currently defines Frequency Range 1 (FR1) as including 410 MHz –7125 MHz, which is often referred to (interchangeably) as “Sub-6 GHz” . Similarly, 3GPP currently defines Frequency Range 2 (FR2) as including 24, 250 MHz –52, 600 MHz, which is sometimes referred to (interchangeably) as a “millimeter wave” ( “mmW” or “mmWave” ) . A base station configured to communicate using mmWave/near mmWave radio frequency bands (e.g., a mmWave base station such as BS 180) may utilize beamforming (e.g., 182) with a UE (e.g., 104) to improve path loss and range.

The communications links 120 between BSs 102 and, for example, UEs 104, may be through one or more carriers, which may have different bandwidths (e.g., 5, 10, 15, 20, 100, 400, and/or other MHz) , and which may be aggregated in various aspects. Carriers may or may not be adjacent to each other. Allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL than for UL) .

Communications using higher frequency bands may have higher path loss and a shorter range compared to lower frequency communications. Accordingly, certain base stations (e.g., 180 in FIG. 1) may utilize beamforming 182 with a UE 104 to improve path loss and range. For example, BS 180 and the UE 104 may each include a plurality of antennas, such as antenna elements, antenna panels, and/or antenna arrays to facilitate the beamforming. In some cases, BS 180 may transmit a beamformed signal to UE 104 in one or more transmit directions 182’. UE 104 may receive the beamformed signal from the BS 180 in one or more receive directions 182”. UE 104 may also transmit a beamformed signal to the BS 180 in one or more transmit directions 182”. BS 180 may also receive the beamformed signal from UE 104 in one or more receive directions 182’. BS 180 and UE 104 may then perform beam training to determine the best receive and transmit directions for each of BS 180 and UE 104. Notably, the transmit and receive directions for BS 180 may or may not be the same. Similarly, the transmit and receive directions for UE 104 may or may not be the same.

Wireless communications network 100 further includes a Wi-Fi AP 150 in communication with Wi-Fi stations (STAs) 152 via communications links 154 in, for example, a 2.4 GHz and/or 5 GHz unlicensed frequency spectrum.

Certain UEs 104 may communicate with each other using device-to-device (D2D) communications link 158. D2D communications link 158 may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH) , a physical sidelink discovery channel (PSDCH) , a physical sidelink shared channel (PSSCH) , a physical sidelink control channel (PSCCH) , and/or a physical sidelink feedback channel (PSFCH) .

EPC 160 may include various functional components, including: a Mobility Management Entity (MME) 162, other MMEs 164, a Serving Gateway 166, a Multimedia Broadcast Multicast Service (MBMS) Gateway 168, a Broadcast Multicast Service Center (BM-SC) 170, and/or a Packet Data Network (PDN) Gateway 172, such as in the depicted example. MME 162 may be in communication with a Home Subscriber Server (HSS) 174. MME 162 is the control node that processes the signaling between the UEs 104 and the EPC 160. Generally, MME 162 provides bearer and connection management.

Generally, user Internet protocol (IP) packets are transferred through Serving Gateway 166, which itself is connected to PDN Gateway 172. PDN Gateway 172 provides UE IP address allocation as well as other functions. PDN Gateway 172 and the BM-SC 170 are connected to IP Services 176, which may include, for example, the Internet, an intranet, an IP Multimedia Subsystem (IMS) , a Packet Switched (PS) streaming service, and/or other IP services.

BM-SC 170 may provide functions for MBMS user service provisioning and delivery. BM-SC 170 may serve as an entry point for content provider MBMS transmission, may be used to authorize and initiate MBMS Bearer Services within a public land mobile network (PLMN) , and/or may be used to schedule MBMS transmissions. MBMS Gateway 168 may be used to distribute MBMS traffic to the BSs 102 belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service, and/or may be responsible for session management (start/stop) and for collecting eMBMS related charging information.

5GC 190 may include various functional components, including: an Access and Mobility Management Function (AMF) 192, other AMFs 193, a Session Management Function (SMF) 194, and a User Plane Function (UPF) 195. AMF 192 may be in communication with Unified Data Management (UDM) 196.

AMF 192 is a control node that processes signaling between UEs 104 and 5GC 190. AMF 192 provides, for example, quality of service (QoS) flow and session management.

Internet protocol (IP) packets are transferred through UPF 195, which is connected to the IP Services 197, and which provides UE IP address allocation as well as other functions for 5GC 190. IP Services 197 may include, for example, the Internet, an intranet, an IMS, a PS streaming service, and/or other IP services.

In various aspects, a network entity or network node can be implemented as an aggregated base station, as a disaggregated base station, a component of a base station, an integrated access and backhaul (IAB) node, a relay node, a sidelink node, to name a few examples.

FIG. 2 depicts an example disaggregated base station 200 architecture. The disaggregated base station 200 architecture may include one or more central units (CUs) 210 that can communicate directly with a core network 220 via a backhaul link, or indirectly with the core network 220 through one or more disaggregated base station units (such as a Near-Real Time (Near-RT) RAN Intelligent Controller (RIC) 225 via an E2 link, or a Non-Real Time (Non-RT) RIC 215 associated with a Service Management and Orchestration (SMO) Framework 205, or both) . A CU 210 may communicate with one or more distributed units (DUs) 230 via respective midhaul links, such as an F1 interface. The DUs 230 may communicate with one or more radio units (RUs) 240 via respective fronthaul links. The RUs 240 may communicate with respective UEs 104 via one or more radio frequency (RF) access links. In some implementations, the UE 104 may be simultaneously served by multiple RUs 240.

Each of the units, e.g., the CUs 210, the DUs 230, the RUs 240, as well as the Near-RT RICs 225, the Non-RT RICs 215 and the SMO Framework 205, may include one or more interfaces or be coupled to one or more interfaces configured to receive or transmit signals, data, or information (collectively, signals) via a wired or wireless transmission medium. Each of the units, or an associated processor or controller providing instructions to the communications interfaces of the units, can be configured to communicate with one or more of the other units via the transmission medium. For example, the units can include a wired interface configured to receive or transmit signals over a wired transmission medium to one or more of the other units. Additionally or alternatively, the units can include a wireless interface, which may include a receiver, a transmitter or transceiver (such as a radio frequency (RF) transceiver) , configured to receive or transmit signals, or both, over a wireless transmission medium to one or more of the other units.

In some aspects, the CU 210 may host one or more higher layer control functions. Such control functions can include radio resource control (RRC) , packet data convergence protocol (PDCP) , service data adaptation protocol (SDAP) , or the like. Each control function can be implemented with an interface configured to communicate signals with other control functions hosted by the CU 210. The CU 210 may be configured to handle user plane functionality (e.g., Central Unit –User Plane (CU-UP) ) , control plane functionality (e.g., Central Unit –Control Plane (CU-CP) ) , or a combination thereof. In some implementations, the CU 210 can be logically split into one or more CU-UP units and one or more CU-CP units. The CU-UP unit can communicate bidirectionally with the CU-CP unit via an interface, such as the E1 interface when implemented in an O-RAN configuration. The CU 210 can be implemented to communicate with the DU 230, as necessary, for network control and signaling.

The DU 230 may correspond to a logical unit that includes one or more base station functions to control the operation of one or more RUs 240. In some aspects, the DU 230 may host one or more of a radio link control (RLC) layer, a medium access control (MAC) layer, and one or more high physical (PHY) layers (such as modules for forward error correction (FEC) encoding and decoding, scrambling, modulation and demodulation, or the like) depending, at least in part, on a functional split, such as those defined by the 3^rd Generation Partnership Project (3GPP) . In some aspects, the DU 230 may further host one or more low PHY layers. Each layer (or module) can be implemented with an interface configured to communicate signals with other layers (and modules) hosted by the DU 230, or with the control functions hosted by the CU 210.

Lower-layer functionality can be implemented by one or more RUs 240. In some deployments, an RU 240, controlled by a DU 230, may correspond to a logical node that hosts RF processing functions, or low-PHY layer functions (such as performing fast Fourier transform (FFT) , inverse FFT (iFFT) , digital beamforming, physical random access channel (PRACH) extraction and filtering, or the like) , or both, based at least in part on the functional split, such as a lower layer functional split. In such an architecture, the RU (s) 240 can be implemented to handle over the air (OTA) communications with one or more UEs 104. In some implementations, real-time and non-real-time aspects of control and user plane communications with the RU (s) 240 can be controlled by the corresponding DU 230. In some scenarios, this configuration can enable the DU (s) 230 and the CU 210 to be implemented in a cloud-based RAN architecture, such as a vRAN architecture.

The SMO Framework 205 may be configured to support RAN deployment and provisioning of non-virtualized and virtualized network elements. For non-virtualized network elements, the SMO Framework 205 may be configured to support the deployment of dedicated physical resources for RAN coverage requirements which may be managed via an operations and maintenance interface (such as an O1 interface) . For virtualized network elements, the SMO Framework 205 may be configured to interact with a cloud computing platform (such as an open cloud (O-Cloud) 290) to perform network element life cycle management (such as to instantiate virtualized network elements) via a cloud computing platform interface (such as an O2 interface) . Such virtualized network elements can include, but are not limited to, CUs 210, DUs 230, RUs 240 and Near-RT RICs 225. In some implementations, the SMO Framework 205 can communicate with a hardware aspect of a 4G RAN, such as an open eNB (O-eNB) 211, via an O1 interface. Additionally, in some implementations, the SMO Framework 205 can communicate directly with one or more RUs 240 via an O1 interface. The SMO Framework 205 also may include a Non-RT RIC 215 configured to support functionality of the SMO Framework 205.

The Non-RT RIC 215 may be configured to include a logical function that enables non-real-time control and optimization of RAN elements and resources, Artificial Intelligence/Machine Learning (AI/ML) workflows including model training and updates, or policy-based guidance of applications/features in the Near-RT RIC 225. The Non-RT RIC 215 may be coupled to or communicate with (such as via an A1 interface) the Near-RT RIC 225. The Near-RT RIC 225 may be configured to include a logical function that enables near-real-time control and optimization of RAN elements and resources via data collection and actions over an interface (such as via an E2 interface) connecting one or more CUs 210, one or more DUs 230, or both, as well as an O-eNB, with the Near-RT RIC 225.

In some implementations, to generate AI/ML models to be deployed in the Near-RT RIC 225, the Non-RT RIC 215 may receive parameters or external enrichment information from external servers. Such information may be utilized by the Near-RT RIC 225 and may be received at the SMO Framework 205 or the Non-RT RIC 215 from non-network data sources or from network functions. In some examples, the Non-RT RIC 215 or the Near-RT RIC 225 may be configured to tune RAN behavior or performance. For example, the Non-RT RIC 215 may monitor long-term trends and patterns for performance and employ AI/ML models to perform corrective actions through the SMO Framework 205 (such as reconfiguration via O1) or via creation of RAN management policies (such as A1 policies) .

FIG. 3 depicts aspects of an example BS 102 and a UE 104.

Generally, BS 102 includes various processors (e.g., 320, 330, 338, and 340) , antennas 334a-t (collectively 334) , transceivers 332a-t (collectively 332) , which include modulators and demodulators, and other aspects, which enable wireless transmission of data (e.g., data source 312) and wireless reception of data (e.g., data sink 339) . For example, BS 102 may send and receive data between BS 102 and UE 104. BS 102 includes controller/processor 340, which may be configured to implement various functions described herein related to wireless communications.

Generally, UE 104 includes various processors (e.g., 358, 364, 366, and 380) , antennas 352a-r (collectively 352) , transceivers 354a-r (collectively 354) , which include modulators and demodulators, and other aspects, which enable wireless transmission of data (e.g., retrieved from data source 362) and wireless reception of data (e.g., provided to data sink 360) . UE 104 includes controller/processor 380, which may be configured to implement various functions described herein related to wireless communications.

In regards to an example downlink transmission, BS 102 includes a transmit processor 320 that may receive data from a data source 312 and control information from a controller/processor 340. The control information may be for the physical broadcast channel (PBCH) , physical control format indicator channel (PCFICH) , physical hybrid automatic repeat request (HARQ) indicator channel (PHICH) , physical downlink control channel (PDCCH) , group common PDCCH (GC PDCCH) , and/or others. The data may be for the physical downlink shared channel (PDSCH) , in some examples.

Transmit processor 320 may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. Transmit processor 320 may also generate reference symbols, such as for the primary synchronization signal (PSS) , secondary synchronization signal (SSS) , PBCH demodulation reference signal (DMRS) , and channel state information reference signal (CSI-RS) .

Transmit (TX) multiple-input multiple-output (MIMO) processor 330 may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, and/or the reference symbols, if applicable, and may provide output symbol streams to the modulators (MODs) in transceivers 332a-332t. Each modulator in transceivers 332a-332t may process a respective output symbol stream to obtain an output sample stream. Each modulator may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. Downlink signals from the modulators in transceivers 332a-332t may be transmitted via the antennas 334a-334t, respectively.

In order to receive the downlink transmission, UE 104 includes antennas 352a-352r that may receive the downlink signals from the BS 102 and may provide received signals to the demodulators (DEMODs) in transceivers 354a-354r, respectively. Each demodulator in transceivers 354a-354r may condition (e.g., filter, amplify, downconvert, and digitize) a respective received signal to obtain input samples. Each demodulator may further process the input samples to obtain received symbols.

RX MIMO detector 356 may obtain received symbols from all the demodulators in transceivers 354a-354r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. Receive processor 358 may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for the UE 104 to a data sink 360, and provide decoded control information to a controller/processor 380.

In regards to an example uplink transmission, UE 104 further includes a transmit processor 364 that may receive and process data (e.g., for the PUSCH) from a data source 362 and control information (e.g., for the physical uplink control channel (PUCCH) ) from the controller/processor 380. Transmit processor 364 may also generate reference symbols for a reference signal (e.g., for the sounding reference signal (SRS) ) . The symbols from the transmit processor 364 may be precoded by a TX MIMO processor 366 if applicable, further processed by the modulators in transceivers 354a-354r (e.g., for SC-FDM) , and transmitted to BS 102.

At BS 102, the uplink signals from UE 104 may be received by antennas 334a-t, processed by the demodulators in transceivers 332a-332t, detected by a RX MIMO detector 336 if applicable, and further processed by a receive processor 338 to obtain decoded data and control information sent by UE 104. Receive processor 338 may provide the decoded data to a data sink 339 and the decoded control information to the controller/processor 340.

Memories 342 and 382 may store data and program codes for BS 102 and UE 104, respectively.

Scheduler 344 may schedule UEs for data transmission on the downlink and/or uplink.

In various aspects, BS 102 may be described as transmitting and receiving various types of data associated with the methods described herein. In these contexts, “transmitting” may refer to various mechanisms of outputting data, such as outputting data from data source 312, scheduler 344, memory 342, transmit processor 320, controller/processor 340, TX MIMO processor 330, transceivers 332a-t, antenna 334a-t, and/or other aspects described herein. Similarly, “receiving” may refer to various mechanisms of obtaining data, such as obtaining data from antennas 334a-t, transceivers 332a-t, RX MIMO detector 336, controller/processor 340, receive processor 338, scheduler 344, memory 342, and/or other aspects described herein.

In various aspects, UE 104 may likewise be described as transmitting and receiving various types of data associated with the methods described herein. In these contexts, “transmitting” may refer to various mechanisms of outputting data, such as outputting data from data source 362, memory 382, transmit processor 364, controller/processor 380, TX MIMO processor 366, transceivers 354a-t, antenna 352a-t, and/or other aspects described herein. Similarly, “receiving” may refer to various mechanisms of obtaining data, such as obtaining data from antennas 352a-t, transceivers 354a-t, RX MIMO detector 356, controller/processor 380, receive processor 358, memory 382, and/or other aspects described herein.

In some aspects, a processor may be configured to perform various operations, such as those associated with the methods described herein, and transmit (output) to or receive (obtain) data from another interface that is configured to transmit or receive, respectively, the data.

FIGS. 4A, 4B, 4C, and 4D depict aspects of data structures for a wireless communications network, such as wireless communications network 100 of FIG. 1.

In particular, FIG. 4A is a diagram 400 illustrating an example of a first subframe within a 5G (e.g., 5G NR) frame structure, FIG. 4B is a diagram 430 illustrating an example of DL channels within a 5G subframe, FIG. 4C is a diagram 450 illustrating an example of a second subframe within a 5G frame structure, and FIG. 4D is a diagram 480 illustrating an example of UL channels within a 5G subframe.

Wireless communications systems may utilize orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) on the uplink and downlink. Such systems may also support half-duplex operation using time division duplexing (TDD) . OFDM and single-carrier frequency division multiplexing (SC-FDM) partition the system bandwidth (e.g., as depicted in FIGS. 4B and 4D) into multiple orthogonal subcarriers. Each subcarrier may be modulated with data. Modulation symbols may be sent in the frequency domain with OFDM and/or in the time domain with SC-FDM.

A wireless communications frame structure may be frequency division duplex (FDD) , in which, for a particular set of subcarriers, subframes within the set of subcarriers are dedicated for either DL or UL. Wireless communications frame structures may also be time division duplex (TDD) , in which, for a particular set of subcarriers, subframes within the set of subcarriers are dedicated for both DL and UL.

In FIG. 4A and 4C, the wireless communications frame structure is TDD where D is DL, U is UL, and X is flexible for use between DL/UL. UEs may be configured with a slot format through a received slot format indicator (SFI) (dynamically through DL control information (DCI) , or semi-statically/statically through radio resource control (RRC) signaling) . In the depicted examples, a 10 ms frame is divided into 10 equally sized 1 ms subframes. Each subframe may include one or more time slots. In some examples, each slot may include 7 or 14 symbols, depending on the slot format. Subframes may also include mini-slots, which generally have fewer symbols than an entire slot. Other wireless communications technologies may have a different frame structure and/or different channels.

In certain aspects, the number of slots within a subframe is based on a slot configuration and a numerology. For example, for slot configuration 0, different numerologies (μ) 0 to 5 allow for 1, 2, 4, 8, 16, and 32 slots, respectively, per subframe. For slot configuration 1, different numerologies 0 to 2 allow for 2, 4, and 8 slots, respectively, per subframe. Accordingly, for slot configuration 0 and numerology μ, there are 14 symbols/slot and 2μ slots/subframe. The subcarrier spacing and symbol length/duration are a function of the numerology. The subcarrier spacing may be equal to 2^μ×15 kHz, where μ is the numerology 0 to 5. As such, the numerology μ=0 has a subcarrier spacing of 15 kHz and the numerology μ=5 has a subcarrier spacing of 480 kHz. The symbol length/duration is inversely related to the subcarrier spacing. FIGS. 4A, 4B, 4C, and 4D provide an example of slot configuration 0 with 14 symbols per slot and numerology μ=2 with 4 slots per subframe. The slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is approximately 16.67 μs.

As depicted in FIGS. 4A, 4B, 4C, and 4D, a resource grid may be used to represent the frame structure. Each time slot includes a resource block (RB) (also referred to as physical RBs (PRBs) ) that extends, for example, 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs) . The number of bits carried by each RE depends on the modulation scheme.

As illustrated in FIG. 4A, some of the REs carry reference (pilot) signals (RS) for a UE (e.g., UE 104 of FIGS. 1 and 3) . The RS may include demodulation RS (DMRS) and/or channel state information reference signals (CSI-RS) for channel estimation at the UE. The RS may also include beam measurement RS (BRS) , beam refinement RS (BRRS) , and/or phase tracking RS (PT-RS) .

FIG. 4B illustrates an example of various DL channels within a subframe of a frame. The physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs) , each CCE including, for example, nine RE groups (REGs) , each REG including, for example, four consecutive REs in an OFDM symbol.

A primary synchronization signal (PSS) may be within symbol 2 of particular subframes of a frame. The PSS is used by a UE (e.g., 104 of FIGS. 1 and 3) to determine subframe/symbol timing and a physical layer identity.

A secondary synchronization signal (SSS) may be within symbol 4 of particular subframes of a frame. The SSS is used by a UE to determine a physical layer cell identity group number and radio frame timing.

Based on the physical layer identity and the physical layer cell identity group number, the UE can determine a physical cell identifier (PCI) . Based on the PCI, the UE can determine the locations of the aforementioned DMRS. The physical broadcast channel (PBCH) , which carries a master information block (MIB) , may be logically grouped with the PSS and SSS to form a synchronization signal (SS) /PBCH block. The MIB provides a number of RBs in the system bandwidth and a system frame number (SFN) . The physical downlink shared channel (PDSCH) carries user data, broadcast system information not transmitted through the PBCH such as system information blocks (SIBs) , and/or paging messages.

As illustrated in FIG. 4C, some of the REs carry DMRS (indicated as R for one particular configuration, but other DMRS configurations are possible) for channel estimation at the base station. The UE may transmit DMRS for the PUCCH and DMRS for the PUSCH. The PUSCH DMRS may be transmitted, for example, in the first one or two symbols of the PUSCH. The PUCCH DMRS may be transmitted in different configurations depending on whether short or long PUCCHs are transmitted and depending on the particular PUCCH format used. UE 104 may transmit sounding reference signals (SRS) . The SRS may be transmitted, for example, in the last symbol of a subframe. The SRS may have a comb structure, and a UE may transmit SRS on one of the combs. The SRS may be used by a base station for channel quality estimation to enable frequency-dependent scheduling on the UL.

FIG. 4D illustrates an example of various UL channels within a subframe of a frame. The PUCCH may be located as indicated in one configuration. The PUCCH carries uplink control information (UCI) , such as scheduling requests, a channel quality indicator (CQI) , a precoding matrix indicator (PMI) , a rank indicator (RI) , and HARQ ACK/NACK feedback. The PUSCH carries data, and may additionally be used to carry a buffer status report (BSR) , a power headroom report (PHR) , and/or UCI.

Aspects Related to Power Control for Transmission of S-SSB

As discussed, certain aspects provide a parameter K referred to as a reference number of times to transmit S-SSB in an SL-BWP, where the transmit power used to transmit the S-SSB in each RB set of a plurality of RB sets of the SL-BWP is based on K. For example, in certain aspects, a wireless communications device, such as UE 104 of FIGS. 1 and 3, receives signaling (e.g., RRC signaling) from another wireless communications device, such as a network entity, such as BS 102 of FIGS. 1 and 3, or a disaggregated base station as discussed with respect to FIG. 2. The signaling includes an indication of K, the reference number of times to transmit S-SSB in an SL-BWP.

In certain aspects, the wireless communications device uses K to determine (e.g., calculate) a maximum transmit (TX) power for the wireless communications device to use to transmit an S-SSB in a single RB set, also referred to as a maximum transmit power per RB set or P_{S-SSB_MAX_RB_SET}. In certain aspects, P_{S-SSB_MAX_RB_SET} is the same for each RB set of the plurality of RB sets in which the wireless communications device transmits an instance of the S-SSB. For example, the wireless communications device may have a maximum transmit power at which it can transmit (e.g., P_CMAX) , such as 23 dB. In certain aspects, P_CMAX is preconfigured at the wireless communications device, or configured via signaling, such as RRC signaling from the other wireless communications device. In certain aspects, P_{S-SSB_MAX_RB_SET} is calculated according to equation (1) as follows:
P_{S-SSB_MAX_RB_SET} = P_CMAX -10*log (K) dBm (1)

The actual transmit power, P_{S-SSB_RB_SET} used by the wireless communications device to transmit a given instance of an S-SSB in a single RB set may be equal to or less than P_{S-SSB_MAX_RB_SET}. For example, the wireless communications device may use power control (e.g., S-SSB power control) which sets P_{S-SSB_RB_SET} to the minimum of P_S- _{SSB_MAX_RB_SET} and a power control function that is based on one or more S-SSB power control parameters (e.g., downlink path loss, one or more constants, etc. ) . Accordingly, P_{S-SSB_RB_SET} is based on P_{S-SSB_MAX_RB_SET}, which is based on K, and therefore, P_S- _{SSB_RB_SET} is based on K.

In certain aspects, P_{S-SSB_RB_SET} is the same for each RB set of the plurality of RB sets in which the wireless communications device transmits an instance of the S-SSB. In certain aspects, P_{S-SSB_RB_SET} may be different for different RB sets of the plurality of RB sets in which the wireless communications device transmits an instance of the S-SSB, such as if the power control function has a different value for different RB sets (e.g., based on different downlink path loss) .

In certain aspects, as discussed, the wireless communications device may be configured to transmit S-SSB in a plurality of RB sets, where a number of the plurality of RB sets is N. For example, the wireless communications device may have N RB sets over which to reserve or maintain a COT, as discussed. The actual number of RB sets over which the wireless communications device transmits S-SSB may be equal to or less than N, based on K, as discussed further herein.

In certain aspects, when N < K, the wireless communications device is configured to transmit S-SSB in all N RB sets, such that the actual number of RB sets over which the wireless communications device transmits S-SSB is equal to N. In particular, if N < K, then the total transmission power (e.g., (P_CMAX -10*log (K) ) *N or less) for transmitting S-SSB in all N RB sets is less than P_CMAX. Therefore, the wireless communications device can reserve or maintain the COT over all the N RB sets, helping to reduce potential interference from other devices performing LBT, and also advantageously transmit each S-SSB with a transmit power up to P_CMAX -10*log (K) , which helps in synchronization reference device selection, by helping RSRP of the S-SSB, as discussed.

FIG. 5 illustrates an example of communication of an S-SSB 502 in each of a plurality of RB sets of an SL-BWP. As shown in FIG. 5, a wireless communications device is configured to transmit S-SSB 502 in four RB sets 1-4, such that N = 4. In one example, assuming K = 5, N < K, so the wireless communications device transmits S-SSB 502 in each of RB sets 1-4.

In certain aspects, when N ≥ K, and the total transmission/transmit power for transmitting S-SSB in all N RB sets (e.g., using P_{S-SSB_RB_SET}) is less than or equal to P_CMAX (e.g., N*P_{S-SSB_RB_SET} ≤ P_CMAX) , the wireless communications device is configured to transmit S-SSB in all N RB sets, such that the actual number of RB sets over which the wireless communications device transmits S-SSB is equal to N. Therefore, the wireless communications device can reserve or maintain the COT over all the N RB sets, helping to reduce potential interference from other devices performing LBT, and also advantageously transmit each S-SSB with a total transmit power that satisfies the requirement of P_CMAX.

Going back to FIG. 5, assuming K = 3, since N = 4, then N ≥ K. Assuming 4*P_{S-SSB_RB_SET} ≤ P_CMAX, the wireless communications device transmits S-SSB 502 in each of RB sets 1-4.

In certain aspects, when N ≥ K, and the total transmission/transmit power for transmitting S-SSB in all N RB sets (e.g., using P_{S-SSB_RB_SET}) is greater than P_CMAX (e.g., N*P_{S-SSB_RB_SET} > P_CMAX) , the wireless communications device is configured to transmit S-SSB in M RB sets, where M < N, such that the actual number of RB sets M over which the wireless communications device transmits S-SSB is less than N. In certain aspects, M is selected (e.g., by the wireless communications device) , such that the total transmission/transmit power for transmitting S-SSB in M RB sets (e.g., using P_S- _{SSB_RB_SET}) is less than or equal to P_CMAX (e.g., M*P_{S-SSB_RB_SET} ≤ P_CMAX) , such that the wireless communications device satisfies the requirement of P_CMAX. For example, M may be selected as the largest value that satisfies M*P_{S-SSB_RB_SET} ≤ P_CMAX. Therefore, the wireless communications device can reserve or maintain the COT over as many of the N RB sets as possible, helping to reduce potential interference from other devices performing LBT, and also advantageously transmit the S-SSBs with a total transmit power that satisfies the requirement of P_CMAX.

In certain aspects, the wireless communications device selects as one of the M RB sets, the anchor RB set used by a receiving wireless communications device receiving the S-SSB.

In certain aspects, the wireless communications device selects the remaining M-1 RB sets other than the anchor RB set randomly from the N-1 RB sets remaining (e.g., the N RB sets excluding the anchor RB set) . Random selection may reduce processing complexity for determining the M RB sets, or may provide randomized coverage of the S-SSB during the COT, to help reduce interference.

FIG. 6 illustrates an example of communication of an S-SSB 602 in each of a plurality of RB sets of an SL-BWP. As shown in FIG. 6, a wireless communications device is configured to transmit S-SSB 602 in four RB sets 1-4, such that N = 4. In the example, RB set 2 is the anchor RB set. In one example, assuming K = 2 and M = 3, the wireless communications device selects RB set 2, the anchor RB set, as one of the M RB sets. Further, the wireless communications device randomly selects the other two RB sets of the M RB sets as RB set 1 and RB set 4, such that the wireless communications device transmits S-SSB 602 in RB sets 1, 2, and 4.

In certain aspects, the wireless communications device selects the remaining M-1 RB sets other than the anchor RB set such that the M RB sets are consecutive in frequency, meaning there are no other RB sets between the selected M RB sets. For example, the M RB sets may be contiguous in frequency. Transmission of S-SSB in consecutive frequency RB sets may reduce out of band interference in the M RB sets from another device that may transmit in one of the N RB sets not selected.

FIG. 7 illustrates an example of communication of an S-SSB 702 in each of a plurality of RB sets of an SL-BWP. As shown in FIG. 7, a wireless communications device is configured to transmit S-SSB 702 in four RB sets 1-4, such that N = 4. In the example, RB set 2 is the anchor RB set. In one example, assuming K = 2 and M = 3, the wireless communications device selects RB set 2, the anchor RB set, as one of the M RB sets. Further, the wireless communications device selects the other two RB sets of the M RB sets to be consecutive with RB set 2, such as selecting RB set 2 and RB set 4, such that the wireless communications device transmits S-SSB 702 in RB sets 2-4. Though not shown, in this example, the wireless communications device could similarly select RB sets 1-3 instead.

In certain aspects, the wireless communications device selects the remaining M-1 RB sets other than the anchor RB set based on priority values associated with PSSCH transmissions scheduled on the RB sets. For example, the wireless communications device may reserve or maintain the COT on the N RB sets in order to transmit in PSSCH in each of the N RB sets, such as after transmitting S-SSB. The PSSCH transmissions may each have an associated priority value (PV) , such as where a lower value is a higher priority. The wireless communications device may be configured to select the M-1 RB sets as the M-1 RB sets having scheduled PSSCH transmissions of the highest priority among the N RB sets. For example, the wireless communications device may be configured to select the M-1 RB sets with ascending order of corresponding priority values over the subsequent PSSCH. Transmission of S-SSB in RB sets having higher priority PSSCH helps ensure that other devices do not transmit during the COT in the RB sets having higher priority PSSCH, thereby reducing the chance for interference for such higher priority PSSCH as opposed to lower priority PSSCH.

FIG. 8 illustrates an example of communication of an S-SSB 802 in each of a plurality of RB sets of an SL-BWP. As shown in FIG. 8, a wireless communications device is configured to transmit S-SSB 802 in four RB sets 1-4, such that N = 4. In the example, RB set 2 is the anchor RB set. In one example, assuming K = 2 and M = 3, the wireless communications device selects RB set 2, the anchor RB set, as one of the M RB sets. Further, the wireless communications device selects the other two RB sets of the M RB sets as those with the highest priority PSSCH among the remaining N-1 RB sets. Here, RB set 4 has a PSSCH with priority value 1, RB set 3 has a PSSCH with priority value 2, and RB set 1 has a PSSCH with priority value 5. Accordingly, RB sets 3 and 4 are selected, such that the wireless communications device transmits S-SSB 802 in RB sets 2-4.

In certain aspects, a receiving wireless communications device receiving the S-SSBs may only monitor the S-SSB in the anchor RB set within the SL-BWP, as discussed.

Aspects Related to Indicating Transmission Locations of S-SSB

As discussed, a receiving wireless communications device is configured to only measure DMRS in PSBCH of the S-SSB communicated in the anchor RB set, and not the other RB sets of the plurality of RB sets in the SL-BWP, and therefore use the anchor RB set to determine a synchronization reference device. However, in certain aspects, the receiving wireless communications device may combine the S-SSBs received in each of the RB sets of the plurality of RB sets so as to enhance the decoding of the S-SSB. For example, for 1%PSBCH block error rate (BLER) detection probability for low signal to noise ratio (SNR) S-SSBs, S-SSB combining may be used. In order to combine the S-SSBs received in each of the RB sets of the plurality of RB sets, the receiving wireless communications device may need information as to which RB sets of the SL-BWP include the S-SSB other than the anchor RB set, as in the receiving wireless communications device may need information on each RB set of the SL-BWP included in the plurality of RB sets used by the wireless communications device to transmit the S-SSB.

Certain aspects provide one or more bits in the DMRS in the PSBCH of the S-SSB communicated in the anchor RB set, where the one or more bits indicate which RB set (s) of the SL-BWP include the S-SSB. For example, the one or more bits may be carried by the DMRS such as scrambled in the DMRS. The receiving wireless communications device may then combine the S-SSB received in each of the RB sets as indicated by the one or more bits.

In certain aspects, the one or more bits (e.g., corresponding to a resource indicator value) indicate a first RB set in frequency among the plurality of RB sets in the SL-BWP that includes S-SSB, and a number of RB sets that include S-SSB. In particular, S-SSB transmission may be in consecutive RB sets in frequency. Accordingly, the receiving wireless communications device can determine the S-SSB is in the first RB set and in consecutive RB sets from the first RB set up to the number of RB sets indicated.

For example, going back to FIG. 7, the one or more bits may indicate the first RB set as RB set 2, and the number of RB sets as 3, such that the one or more bits indicate that RB sets 2-4 include the S-SSB 702.

In certain aspects, the one or more bits represent a relative bitmap indicating which RB sets include S-SSB starting from the anchor RB set. For example, each bit of the bitmap (e.g., starting from the most significant bit (MSB) or the least significant bit (LSB) ) maps to one of the RB sets other than the anchor RB set. In an example, the first bit (e.g., MSB or LSB) maps to an RB set consecutive with the anchor RB set (e.g., with a higher or lower frequency) . Subsequent bits map to further consecutive RB sets. Further, if the end of the RB sets (e.g., highest frequency or lowest frequency) is reached and there are additional bits, bit mapping wraps around to the other end of the RB sets. Accordingly, a number of the one or more bits is one less than the number of RB sets in the SL-BWP. The RB sets including S-SSB need not be consecutive.

For example, going back to FIG. 6, the anchor RB set may be RB set 2, and the S-SSB 602 is transmitted in RB sets, 1, 2, and 4. Accordingly, the one or more bits may be 011, where the MSB 0 indicates that the consecutive RB set with higher frequency then RB set 2, i.e., RB set 3, does not include S-SSB. The next bit 1, indicates that the consecutive RB set with higher frequency then RB set 3, i.e., RB set 4, does include S-SSB 602. As RB set 4 is the end of the RB sets 1-4, the bit mapping wraps to the other end of the RB sets, i.e., to RB set 1, such that the next bit 1, indicates that RB set 1 does include S-SSB 602.

In certain aspects, the one or more bits represent an absolute bitmap indicating which RB sets include S-SSB in the SL-BWP. For example, each bit of the bitmap (e.g., starting from the most significant bit (MSB) or the least significant bit (LSB) ) maps to one of the RB sets in the SL-BWP. In an example, the first bit (e.g., MSB or LSB) maps to the highest or lowest frequency RB set. Subsequent bits map to further consecutive RB sets. Accordingly, a number of the one or more bits is equal to the number of RB sets in the SL-BWP. The RB sets including S-SSB need not be consecutive.

For example, going back to FIG. 6, the anchor RB set may be RB set 2, and the S-SSB 602 is transmitted in RB sets, 1, 2, and 4. Accordingly, the one or more bits may be 1101, where the MSB 1 indicates that the RB set with the lowest frequency, i.e., RB set 1, does include S-SSB 602. The next bit 1, indicates that the consecutive RB set with higher frequency then RB set 1, i.e., RB set 2, does include S-SSB 602. The next bit 0, indicates that the consecutive RB set with higher frequency then RB set 2, i.e., RB set 3, does not include S-SSB 602. The next bit 1, indicates that the consecutive RB set with higher frequency then RB set 3, i.e., RB set 4, does include S-SSB 602.

Example Operations

FIG. 9 shows a method 900 for wireless communications by an apparatus, such as UE 104 of FIGS. 1 and 3.

Method 900 begins at step 905 with receiving an indication of a reference number of times to transmit S-SSB in a SL-BWP.

Method 900 then proceeds to step 910 with transmitting, in each of a plurality of RB sets, a first S-SSB using a first transmit power, wherein the first transmit power is based on the reference number of times to transmit S-SSB.

In certain aspects, step 905 includes receiving the indication of the reference number of times to transmit S-SSB via RRC signaling.

In certain aspects, the first transmit power being based on the reference number of times to transmit S-SSB comprises: a maximum transmit power per RB set being based on the reference number of times to transmit S-SSB; and the first transmit power being based on the maximum transmit power per RB set and one or more S-SSB power control parameters.

In certain aspects, a number of the plurality of RB sets is based on a number of RB sets over which the apparatus is to maintain a COT.

In certain aspects, the number of the plurality of RB sets is equal to the number of RB sets over which the apparatus is to maintain a COT based on the number of RB sets over which the apparatus is to maintain a COT being less than the reference number of times to transmit S-SSB.

In certain aspects, the number of the plurality of RB sets is equal to the number of RB sets over which the apparatus is to maintain a COT based on: the number of RB sets over which the apparatus is to maintain a COT being greater than or equal to the reference number of times to transmit S-SSB; and a total transmit power for transmitting the first S-SSB in each of the plurality of RB sets using the first transmit power being less than or equal to a maximum total transmit power for the apparatus.

In certain aspects, the number of the plurality of RB sets is less than the number of RB sets over which the apparatus is to maintain a COT based on: the number of RB sets over which the apparatus is to maintain a COT being greater than or equal to the reference number of times to transmit S-SSB; and a total transmit power for transmitting the first S-SSB in each of the plurality of RB sets using the first transmit power being greater than a maximum total transmit power for the apparatus.

In certain aspects, the plurality of RB sets comprises an anchor RB set of the SL-BWP and one or more RB sets randomly selected from the RB sets over which the apparatus is to maintain a COT.

In certain aspects, the plurality of RB sets are consecutive RB sets in frequency of the RB sets over which the apparatus is to maintain a COT, and wherein the plurality of RB sets comprises an anchor RB set of the SL-BWP.

In certain aspects, the plurality of RB sets comprises an anchor RB set of the SL-BWP and one or more RB sets selected from the RB sets over which the apparatus is to maintain a COT based on priority values associated with PSSCH transmissions scheduled on the RB sets over which the apparatus is to maintain a COT.

In certain aspects, method 900, or any aspect related to it, may be performed by an apparatus, such as communications device 1100 of FIG. 11, which includes various components operable, configured, or adapted to perform the method 900. Communications device 1100 is described below in further detail.

Note that FIG. 9 is just one example of a method, and other methods including fewer, additional, or alternative steps are possible consistent with this disclosure.

FIG. 10 shows a method 1000 for wireless communications by an apparatus, such as UE 104 of FIGS. 1 and 3.

Method 1000 begins at step 1005 with receiving PSBCH including DMRS in an anchor RB set of a SL-BWP comprising a plurality of RB sets, the DMRS carrying one or more bits that identify one or more RB sets of the plurality of RB sets as including a first S-SSB.

Method 1000 then proceeds to step 1010 with receiving the first S-SSB in each of the one or more RB sets.

In certain aspects, the one or more bits indicate a first RB set in frequency among the plurality of RB sets to include in the one or more RB sets and a number of the one or more RB sets, wherein the one or more RB sets are consecutive RB sets in frequency of the plurality of RB sets.

In certain aspects, the one or more bits are a resource indicator value.

In certain aspects, a number of the one or more bits is one less than a number of the plurality of RB sets, and wherein each of the one or more bits maps to a different RB set of the plurality of RB sets other than the anchor RB set.

In certain aspects, a number of the one or more bits equals a number of the plurality of RB sets, and wherein each of the one or more bits maps to a different RB set of the plurality of RB sets.

In certain aspects, method 1000 further includes combining the first S-SSB received in each of the one or more RB sets to decode the first S-SSB.

In certain aspects, method 1000, or any aspect related to it, may be performed by an apparatus, such as communications device 1200 of FIG. 12, which includes various components operable, configured, or adapted to perform the method 1000. Communications device 1200 is described below in further detail.

Note that FIG. 10 is just one example of a method, and other methods including fewer, additional, or alternative steps are possible consistent with this disclosure.

Example Communications Devices

FIG. 11 depicts aspects of an example communications device 1100. In some aspects, communications device 1100 is a user equipment, such as UE 104 described above with respect to FIGS. 1 and 3.

The communications device 1100 includes a processing system 1105 coupled to a transceiver 1145 (e.g., a transmitter and/or a receiver) . The transceiver 1145 is configured to transmit and receive signals for the communications device 1100 via an antenna 1150, such as the various signals as described herein. The processing system 1105 may be configured to perform processing functions for the communications device 1100, including processing signals received and/or to be transmitted by the communications device 1100.

The processing system 1105 includes one or more processors 1110. In various aspects, the one or more processors 1110 may be representative of one or more of receive processor 358, transmit processor 364, TX MIMO processor 366, and/or controller/processor 380, as described with respect to FIG. 3. The one or more processors 1110 are coupled to a computer-readable medium/memory 1125 via a bus 1140. In certain aspects, the computer-readable medium/memory 1125 is configured to store instructions (e.g., computer-executable code) that when executed by the one or more processors 1110, enable and cause the one or more processors 1110 to perform the method 900 described with respect to FIG. 9, or any aspect related to it, including any additional steps or sub-steps described in relation to FIG. 9; and the method 1000 described with respect to FIG. 10, or any aspect related to it, including any additional steps or sub-steps described in relation to FIG. 10. Note that reference to a processor performing a function of communications device 1100 may include one or more processors performing that function of communications device 1100, such as in a distributed fashion.

In the depicted example, computer-readable medium/memory 1125 stores code for receiving 1130 and code for transmitting 1135. Processing of the code 1130 and code for transmitting 1135 may enable and cause the communications device 1100 to perform the method 900 described with respect to FIG. 9, or any aspect related to it; and the method 1000 described with respect to FIG. 10, or any aspect related to it.

The one or more processors 1110 include circuitry configured to implement (e.g., execute) the code stored in the computer-readable medium/memory 1125, including circuitry for receiving 1115 and circuitry for transmitting 1120. Processing with circuitry for receiving 1115 and circuitry for transmitting 1120 may enable and cause the communications device 1100 to perform the method 900 described with respect to FIG. 9, or any aspect related to it; and the method 1000 described with respect to FIG. 10, or any aspect related to it.

More generally, means for communicating, transmitting, sending or outputting for transmission may include the transceivers 354, antenna (s) 352, transmit processor 364, TX MIMO processor 366, and/or controller/processor 380 of the UE 104 illustrated in FIG. 3, transceiver 1145 and/or antenna 1150 of the communications device 1100 in FIG. 11, and/or one or more processors 1110 of the communications device 1100 in FIG. 11. Means for communicating, receiving or obtaining may include the transceivers 354, antenna (s) 352, receive processor 358, and/or controller/processor 380 of the UE 104 illustrated in FIG. 3, transceiver 1145 and/or antenna 1150 of the communications device 1100 in FIG. 11, and/or one or more processors 1110 of the communications device 1100 in FIG. 11.

FIG. 12 depicts aspects of an example communications device 1200. In some aspects, communications device 1200 is a user equipment, such as UE 104 described above with respect to FIGS. 1 and 3.

The communications device 1200 includes a processing system 1205 coupled to a transceiver 1245 (e.g., a transmitter and/or a receiver) . The transceiver 1245 is configured to transmit and receive signals for the communications device 1200 via an antenna 1250, such as the various signals as described herein. The processing system 1205 may be configured to perform processing functions for the communications device 1200, including processing signals received and/or to be transmitted by the communications device 1200.

The processing system 1205 includes one or more processors 1210. In various aspects, the one or more processors 1210 may be representative of one or more of receive processor 358, transmit processor 364, TX MIMO processor 366, and/or controller/processor 380, as described with respect to FIG. 3. The one or more processors 1210 are coupled to a computer-readable medium/memory 1225 via a bus 1240. In certain aspects, the computer-readable medium/memory 1225 is configured to store instructions (e.g., computer-executable code) that when executed by the one or more processors 1210, enable and cause the one or more processors 1210 to perform the method 900 described with respect to FIG. 9, or any aspect related to it, including any additional steps or sub-steps described in relation to FIG. 9; and the method 1000 described with respect to FIG. 10, or any aspect related to it, including any additional steps or sub-steps described in relation to FIG. 10. Note that reference to a processor performing a function of communications device 1200 may include one or more processors performing that function of communications device 1200, such as in a distributed fashion.

In the depicted example, computer-readable medium/memory 1225 stores code for receiving 1230 and code for combining 1235. Processing of the code for receiving 1230 and code for combining 1235 may enable and cause the communications device 1200 to perform the method 900 described with respect to FIG. 9, or any aspect related to it; and the method 1000 described with respect to FIG. 10, or any aspect related to it.

The one or more processors 1210 include circuitry configured to implement (e.g., execute) the code stored in the computer-readable medium/memory 1225, including circuitry for receiving 1215 and circuitry for combining 1220. Processing with circuitry for receiving 1215 and circuitry for combining 1220 may enable and cause the communications device 1200 to perform the method 900 described with respect to FIG. 9, or any aspect related to it; and the method 1000 described with respect to FIG. 10, or any aspect related to it.

More generally, means for communicating, transmitting, sending or outputting for transmission may include the transceivers 354, antenna (s) 352, transmit processor 364, TX MIMO processor 366, and/or controller/processor 380 of the UE 104 illustrated in FIG. 3, transceiver 1245 and/or antenna 1250 of the communications device 1200 in FIG. 12, and/or one or more processors 1210 of the communications device 1200 in FIG. 12. Means for communicating, receiving or obtaining may include the transceivers 354, antenna (s) 352, receive processor 358, and/or controller/processor 380 of the UE 104 illustrated in FIG. 3, transceiver 1245 and/or antenna 1250 of the communications device 1200 in FIG. 12, and/or one or more processors 1210 of the communications device 1200 in FIG. 12.

Example Clauses

Implementation examples are described in the following numbered clauses:

Clause 1: A method for wireless communications by an apparatus comprising: receiving an indication of a reference number of times to transmit S-SSB in a SL-BWP; and transmitting, in each of a plurality of RB sets, a first S-SSB using a first transmit power, wherein the first transmit power is based on the reference number of times to transmit S-SSB.

Clause 2: The method of Clause 1, wherein receiving the indication of the reference number of times to transmit S-SSB further comprises receiving the indication of the reference number of times to transmit S-SSB via RRC signaling.

Clause 3: The method of any one of Clauses 1-2, wherein the first transmit power being based on the reference number of times to transmit S-SSB comprises: a maximum transmit power per RB set being based on the reference number of times to transmit S-SSB; and the first transmit power being based on the maximum transmit power per RB set and one or more S-SSB power control parameters.

Clause 4: The method of any one of Clauses 1-3, wherein a number of the plurality of RB sets is based on a number of RB sets over which the apparatus is to maintain a COT.

Clause 5: The method of Clause 4, wherein the number of the plurality of RB sets is equal to the number of RB sets over which the apparatus is to maintain a COT based on the number of RB sets over which the apparatus is to maintain a COT being less than the reference number of times to transmit S-SSB.

Clause 6: The method of Clause 4, wherein the number of the plurality of RB sets is equal to the number of RB sets over which the apparatus is to maintain a COT based on: the number of RB sets over which the apparatus is to maintain a COT being greater than or equal to the reference number of times to transmit S-SSB; and a total transmit power for transmitting the first S-SSB in each of the plurality of RB sets using the first transmit power being less than or equal to a maximum total transmit power for the apparatus.

Clause 7: The method of Clause 4, wherein the number of the plurality of RB sets is less than the number of RB sets over which the apparatus is to maintain a COT based on: the number of RB sets over which the apparatus is to maintain a COT being greater than or equal to the reference number of times to transmit S-SSB; and a total transmit power for transmitting the first S-SSB in each of the plurality of RB sets using the first transmit power being greater than a maximum total transmit power for the apparatus.

Clause 8: The method of Clause 7, wherein the plurality of RB sets comprises an anchor RB set of the SL-BWP and one or more RB sets randomly selected from the RB sets over which the apparatus is to maintain a COT.

Clause 9: The method of Clause 7, wherein the plurality of RB sets are consecutive RB sets in frequency of the RB sets over which the apparatus is to maintain a COT, and wherein the plurality of RB sets comprises an anchor RB set of the SL-BWP.

Clause 10: The method of Clause 7, wherein the plurality of RB sets comprises an anchor RB set of the SL-BWP and one or more RB sets selected from the RB sets over which the apparatus is to maintain a COT based on priority values associated with PSSCH transmissions scheduled on the RB sets over which the apparatus is to maintain a COT.

Clause 11: A method for wireless communications by an apparatus comprising: receiving PSBCH including DMRS in an anchor RB set of a SL-BWP comprising a plurality of RB sets, the DMRS carrying one or more bits that identify one or more RB sets of the plurality of RB sets as including a first S-SSB; and receiving the first S-SSB in each of the one or more RB sets.

Clause 12: The method of Clause 11, wherein the one or more bits indicate a first RB set in frequency among the plurality of RB sets to include in the one or more RB sets and a number of the one or more RB sets, wherein the one or more RB sets are consecutive RB sets in frequency of the plurality of RB sets.

Clause 13: The method of Clause 12, wherein the one or more bits are a resource indicator value.

Clause 14: The method of Clause 11, wherein a number of the one or more bits is one less than a number of the plurality of RB sets, and wherein each of the one or more bits maps to a different RB set of the plurality of RB sets other than the anchor RB set.

Clause 15: The method of Clause 11, wherein a number of the one or more bits equals a number of the plurality of RB sets, and wherein each of the one or more bits maps to a different RB set of the plurality of RB sets.

Clause 16: The method of any one of Clauses 11-15, further comprising: combining the first S-SSB received in each of the one or more RB sets to decode the first S-SSB.

Clause 17: One or more apparatuses, comprising: one or more memories comprising executable instructions; and one or more processors configured to execute the executable instructions and cause the one or more apparatuses to perform a method in accordance with any one of clauses 1-16.

Clause 18: One or more apparatuses, comprising means for performing a method in accordance with any one of clauses 1-16.

Clause 19: One or more non-transitory computer-readable media comprising executable instructions that, when executed by one or more processors of one or more apparatuses, cause the one or more apparatuses to perform a method in accordance with any one of clauses 1-16.

Clause 20: One or more computer program products embodied on one or more computer-readable storage media comprising code for performing a method in accordance with any one of clauses 1-16.

Additional Considerations

The preceding description is provided to enable any person skilled in the art to practice the various aspects described herein. The examples discussed herein are not limiting of the scope, applicability, or aspects set forth in the claims. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. For example, changes may be made in the function and arrangement of elements discussed without departing from the scope of the disclosure. Various examples may omit, substitute, or add various procedures or components as appropriate. For instance, the methods described may be performed in an order different from that described, and various actions may be added, omitted, or combined. Also, features described with respect to some examples may be combined in some other examples. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, the scope of the disclosure is intended to cover such an apparatus or method that is practiced using other structure, functionality, or structure and functionality in addition to, or other than, the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of a claim.

The various illustrative logical blocks, modules and circuits described in connection with the present disclosure may be implemented or performed with a general purpose processor, a digital signal processor (DSP) , an ASIC, a field programmable gate array (FPGA) or other programmable logic device (PLD) , 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 commercially available processor, controller, microcontroller, or state machine. A 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, a system on a chip (SoC) , or any other such configuration.

As used herein, a phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combination with multiples of the same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c) .

As used herein, the term “determining” encompasses a wide variety of actions. For example, “determining” may include calculating, computing, processing, deriving, investigating, looking up (e.g., looking up in a table, a database or another data structure) , ascertaining and the like. Also, “determining” may include receiving (e.g., receiving information) , accessing (e.g., accessing data in a memory) and the like. Also, “determining” may include resolving, selecting, choosing, establishing and the like.

As used herein, “coupled to” and “coupled with” generally encompass direct coupling and indirect coupling (e.g., including intermediary coupled aspects) unless stated otherwise. For example, stating that a processor is coupled to a memory allows for a direct coupling or a coupling via an intermediary aspect, such as a bus.

The methods disclosed herein comprise one or more actions for achieving the methods. The method actions may be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of actions is specified, the order and/or use of specific actions may be modified without departing from the scope of the claims. Further, the various operations of methods described above may be performed by any suitable means capable of performing the corresponding functions. The means may include various hardware and/or software component (s) and/or module (s) , including, but not limited to a circuit, an application specific integrated circuit (ASIC) , or processor.

The following claims are not intended to be limited to the aspects shown herein, but are to be accorded the full scope consistent with the language of the claims. Reference to an element in the singular is not intended to mean only one unless specifically so stated, but rather “one or more. ” For example, reference to an element (e.g., “a processor, ” “a controller, ” “a memory, ” etc. ) , unless otherwise specifically stated, should be understood to refer to one or more elements (e.g., “one or more processors, ” “one or more controllers, ” “one or more memories, ” etc. ) . The terms “set” and “group” are intended to include one or more elements, and may be used interchangeably with “one or more. ” Where reference is made to one or more elements performing functions (e.g., steps of a method) , one element may perform all functions, or more than one element may collectively perform the functions. When more than one element collectively performs the functions, each function need not be performed by each of those elements (e.g., different functions may be performed by different elements) and/or each function need not be performed in whole by only one element (e.g., different elements may perform different sub-functions of a function) . Similarly, where reference is made to one or more elements configured to cause another element (e.g., an apparatus) to perform functions, one element may be configured to cause the other element to perform all functions, or more than one element may collectively be configured to cause the other element to perform the functions. Unless specifically stated otherwise, the term “some” refers to one or more. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims.

Claims

An apparatus configured for wireless communications, comprising: one or more memories comprising processor-executable instructions; and one or more processors configured to execute the processor-executable instructions and cause the apparatus to:

receive an indication of a reference number of times to transmit sidelink synchronization signal block (S-SSB) in a sidelink bandwidth part (SL-BWP) ; and

in each of a plurality of resource block (RB) sets, transmit a first S-SSB using a first transmit power, wherein the first transmit power is based on the reference number of times to transmit S-SSB.
The apparatus of claim 1, wherein, to receive the indication of the reference number of times to transmit S-SSB, the one or more processors are configured to execute the processor-executable instructions and cause the apparatus to:

receive the indication of the reference number of times to transmit S-SSB via radio resource control (RRC) signaling.
The apparatus of claim 1, wherein the first transmit power being based on the reference number of times to transmit S-SSB comprises:

a maximum transmit power per RB set being based on the reference number of times to transmit S-SSB; and

the first transmit power being based on the maximum transmit power per RB set and one or more S-SSB power control parameters.
The apparatus of claim 1, wherein a number of the plurality of RB sets is based on a number of RB sets over which the apparatus is to maintain a channel occupancy time (COT) .
The apparatus of claim 4, wherein the number of the plurality of RB sets is equal to the number of RB sets over which the apparatus is to maintain a COT based on the number of RB sets over which the apparatus is to maintain a COT being less than the reference number of times to transmit S-SSB.
The apparatus of claim 4, wherein the number of the plurality of RB sets is equal to the number of RB sets over which the apparatus is to maintain a COT based on:

the number of RB sets over which the apparatus is to maintain a COT being greater than or equal to the reference number of times to transmit S-SSB; and

a total transmit power for transmitting the first S-SSB in each of the plurality of RB sets using the first transmit power being less than or equal to a maximum total transmit power for the apparatus.
The apparatus of claim 4, wherein the number of the plurality of RB sets is less than the number of RB sets over which the apparatus is to maintain a COT based on:

the number of RB sets over which the apparatus is to maintain a COT being greater than or equal to the reference number of times to transmit S-SSB; and

a total transmit power for transmitting the first S-SSB in each of the plurality of RB sets using the first transmit power being greater than a maximum total transmit power for the apparatus.
The apparatus of claim 7, wherein the plurality of RB sets comprises an anchor RB set of the SL-BWP and one or more RB sets randomly selected from the RB sets over which the apparatus is to maintain a COT.
The apparatus of claim 7, wherein the plurality of RB sets are consecutive RB sets in frequency of the RB sets over which the apparatus is to maintain a COT, and wherein the plurality of RB sets comprises an anchor RB set of the SL-BWP.
The apparatus of claim 7, wherein the plurality of RB sets comprises an anchor RB set of the SL-BWP and one or more RB sets selected from the RB sets over which the apparatus is to maintain a COT based on priority values associated with physical sidelink shared channel (PSSCH) transmissions scheduled on the RB sets over which the apparatus is to maintain a COT.
An apparatus configured for wireless communications, comprising: one or more memories comprising processor-executable instructions; and one or more processors configured to execute the processor-executable instructions and cause the apparatus to:

receive physical sidelink broadcast channel (PSBCH) including demodulation reference signal (DMRS) in an anchor resource block (RB) set of a sidelink bandwidth part (SL-BWP) comprising a plurality of RB sets, the DMRS carrying one or more bits that identify one or more RB sets of the plurality of RB sets as including a first sidelink synchronization signal block (S-SSB) ; and

receive the first S-SSB in each of the one or more RB sets.
The apparatus of claim 11, wherein the one or more bits indicate a first RB set in frequency among the plurality of RB sets to include in the one or more RB sets and a number of the one or more RB sets, wherein the one or more RB sets are consecutive RB sets in frequency of the plurality of RB sets.
The apparatus of claim 12, wherein the one or more bits are a resource indicator value.
The apparatus of claim 11, wherein a number of the one or more bits is one less than a number of the plurality of RB sets, and wherein each of the one or more bits maps to a different RB set of the plurality of RB sets other than the anchor RB set.
The apparatus of claim 11, wherein a number of the one or more bits equals a number of the plurality of RB sets, and wherein each of the one or more bits maps to a different RB set of the plurality of RB sets.
The apparatus of claim 11, wherein the one or more processors are configured to execute the processor-executable instructions and cause the apparatus to:

combine the first S-SSB received in each of the one or more RB sets to decode the first S-SSB.
A method for wireless communications by an apparatus comprising:

receiving an indication of a reference number of times to transmit sidelink synchronization signal block (S-SSB) in a sidelink bandwidth part (SL-BWP) ; and

in each of a plurality of resource block (RB) sets, transmitting a first S-SSB using a first transmit power, wherein the first transmit power is based on the reference number of times to transmit S-SSB.
The method of claim 17, wherein receiving the indication of the reference number of times to transmit S-SSB further comprises:

receiving the indication of the reference number of times to transmit S-SSB via radio resource control (RRC) signaling.
The method of claim 17, wherein the first transmit power being based on the reference number of times to transmit S-SSB comprises:

a maximum transmit power per RB set being based on the reference number of times to transmit S-SSB; and

the first transmit power being based on the maximum transmit power per RB set and one or more S-SSB power control parameters.
The method of claim 17, wherein a number of the plurality of RB sets is based on a number of RB sets over which the apparatus is to maintain a channel occupancy time (COT) .
The method of claim 20, wherein the number of the plurality of RB sets is equal to the number of RB sets over which the apparatus is to maintain a COT based on the number of RB sets over which the apparatus is to maintain a COT being less than the reference number of times to transmit S-SSB.
The method of claim 20, wherein the number of the plurality of RB sets is equal to the number of RB sets over which the apparatus is to maintain a COT based on:

the number of RB sets over which the apparatus is to maintain a COT being greater than or equal to the reference number of times to transmit S-SSB; and

a total transmit power for transmitting the first S-SSB in each of the plurality of RB sets using the first transmit power being less than or equal to a maximum total transmit power for the apparatus.
The method of claim 20, wherein the number of the plurality of RB sets is less than the number of RB sets over which the apparatus is to maintain a COT based on:

the number of RB sets over which the apparatus is to maintain a COT being greater than or equal to the reference number of times to transmit S-SSB; and

a total transmit power for transmitting the first S-SSB in each of the plurality of RB sets using the first transmit power being greater than a maximum total transmit power for the apparatus.
The method of claim 23, wherein the plurality of RB sets comprises an anchor RB set of the SL-BWP and one or more RB sets randomly selected from the RB sets over which the apparatus is to maintain a COT.
The method of claim 23, wherein the plurality of RB sets are consecutive RB sets in frequency of the RB sets over which the apparatus is to maintain a COT, and wherein the plurality of RB sets comprises an anchor RB set of the SL-BWP.
The method of claim 23, wherein the plurality of RB sets comprises an anchor RB set of the SL-BWP and one or more RB sets selected from the RB sets over which the apparatus is to maintain a COT based on priority values associated with physical sidelink shared channel (PSSCH) transmissions scheduled on the RB sets over which the apparatus is to maintain a COT.
A method for wireless communications by an apparatus comprising:

receiving physical sidelink broadcast channel (PSBCH) including demodulation reference signal (DMRS) in an anchor resource block (RB) set of a sidelink bandwidth part (SL-BWP) comprising a plurality of RB sets, the DMRS carrying one or more bits that identify one or more RB sets of the plurality of RB sets as including a first sidelink synchronization signal block (S-SSB) ; and

receiving the first S-SSB in each of the one or more RB sets.
The method of claim 27, wherein the one or more bits indicate a first RB set in frequency among the plurality of RB sets to include in the one or more RB sets and a number of the one or more RB sets, wherein the one or more RB sets are consecutive RB sets in frequency of the plurality of RB sets.
The method of claim 28, wherein the one or more bits are a resource indicator value.
The method of claim 27, wherein a number of the one or more bits is one less than a number of the plurality of RB sets, and wherein each of the one or more bits maps to a different RB set of the plurality of RB sets other than the anchor RB set.