METHOD AND APPARATUS FOR COVERAGE EXTENSION OF SIDELINK SYNCHRONIZATION SIGNAL BLOCK - Patent application

Abstract

Systems and methods for coverage extension for sidelink (SL) synchronization signal blocks (SSBs) (S-SSBs) between a transmitting (Tx) user equipment (UE) and a receiving (Rx) UE are disclosed herein. S-SSB frequency domain extension may use S-SSBs using an increased number of physical radio bearers (PRBs) and / or frequency hopping for S-SSBs. S-SSB time domain extension may change the S-SSB periodicity, the number of S-SSBs per period, use a clear channel assessment (CCA) (or listen-before-talk (LBT)) procedure, and / or transmit only a portion of the set of S-SSBs configured for the S-SSB periodicity. Multi-beam S-SSB extension may index the S-SSBs in the configured set and transmit those S-SSBs using a beam corresponding to the index. S-SSB extension using frequency domain masking and / or time domain masking may apply different masks to one or more S-SSBs.

Description

[Technical field]

[0001] The present application relates generally to wireless communication systems, including wireless communication systems that implement sidelink (SL) communications. [Background technology]

[0002] Wireless mobile communication technologies use various standards and protocols to transmit data between base stations and wireless communication devices. Wireless communication system standards and protocols can include, for example, 3rd Generation Partnership Project (3GPP) long term evolution (LTE) (e.g., 4G), 3GPP new radio (NR) (e.g., 5G), and the IEEE 802.11 standard for wireless local area networks (WLANs), commonly known to industry groups as Wi-Fi.

[0003] As contemplated by 3GPP, different wireless communication system standards and protocols may use various Radio Access Networks (RANs) for communication between base stations of the RAN (which may also be commonly referred to as RAN nodes, network nodes, or simply nodes) and wireless communication devices known as user equipment (UE). 3GPP RANs may include, for example, Global System for Mobile Communications (GSM), Enhanced Data Rates for GSM Evolution (EDGE) RAN (GERAN), Universal Terrestrial Radio Access Network (UTRAN), Evolved Universal Terrestrial Radio Access Network (E-UTRAN), and / or Next Generation Radio Access Network (NG-RAN).

[0004] Each RAN may perform communications between base stations and UEs using one or more radio access technologies (RATs). For example, a GERAN may implement a GSM and / or EDGE RAT, a UTRAN may implement a universal mobile telecommunication system (UMTS) RAT or other 3GPP RAT, an E-UTRAN may implement an LTE RAT (sometimes referred to simply as LTE), and an NG-RAN may implement an NR RAT (sometimes referred to herein as a 5G RAT, a 5G NR RAT, or simply NR). In certain deployments, an E-UTRAN may also implement an NR RAT. In certain deployments, an NG-RAN may also implement an LTE RAT.

[0005] A base station used by a RAN may correspond to that RAN. An example of an E-UTRAN base station is an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Node B (also commonly referred to as an evolved Node B, enhanced Node B, eNode B, or eNB). An example of an NG-RAN base station is a Next Generation Node B (sometimes referred to as a Node B or gNB).

[0006] The RAN provides communication services with external entities via a connection to a Core Network (CN), for example, the E-UTRAN may utilize the Evolved Packet Core (EPC) and the NG-RAN may utilize the 5G Core Network (5GC).

[0007] The 5G NR frequency band can be divided into two or more different frequency ranges. For example, Frequency Range 1 (FR1) may include frequency bands operating in sub-6 GHz frequencies, some of which may be used by previous standards and potentially may be extended to cover new frequency bands providing 410 MHz to 7125 MHz. Frequency Range 2 (FR2) may include frequency bands from 24.25 GHz to 52.6 GHz. Note that in some systems, FR2 may also include frequency bands from 52.6 GHz to 71 GHz (or more). The millimeter wave (mmWave) range bands of FR2 may have a smaller range than the bands of FR1, but the available bandwidth is potentially wider. Those skilled in the art will appreciate that these frequency ranges provided as examples may vary from time to time or from region to region.

[0008] To easily identify the discussion of any particular element or act, the most significant digit(s) of a reference number refers to the figure number in which that element is first introduced. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 shows a diagram illustrating a timeline of S-SSB transmission by a TxUE according to one embodiment.

[0010] [Diagram 2] 4 illustrates a frequency hopping pattern used for S-SSB transmission according to one embodiment of the present invention.

[0011] [Diagram 3] 1 illustrates the use of repeated S-SSB in the frequency domain according to one embodiment.

[0012] [Figure 4] 1 illustrates a UE method for SL communication according to one embodiment.

[0013] [Diagram 5] 1 illustrates a UE method for SL communication according to one embodiment.

[0014] [Figure 6] 1 illustrates a method for S-SSB time domain extension according to one embodiment.

[0015] [Figure 7] 1 illustrates a method for S-SSB time domain extension according to one embodiment.

[0016] [Figure 8] 1 illustrates a method for S-SSB time domain extension according to one embodiment.

[0017] [Figure 9] FIG. 1 shows a diagram illustrating a timeline of S-SSB transmission by a TxUE when using CCA / LBT according to one embodiment.

[0018] [Figure 10] 1 illustrates a method for S-SSB time domain extension according to one embodiment.

[0019] [Figure 11] 1 illustrates a method for S-SSB time domain extension according to one embodiment.

[0020] [Figure 12] A diagram showing transmission of S-SSB by TxUE in a beamforming manner according to one embodiment is shown.

[0021] [Figure 13] 1 illustrates a UE method for SL communication according to one embodiment.

[0022] [Figure 14] 1 shows a diagram corresponding to a first option and a second option for performing frequency domain masking according to one embodiment;

[0023] [Figure 15]1 shows a diagram corresponding to time domain masking according to one embodiment.

[0024] [Figure 16] 1 illustrates a UE method for SL communication according to one embodiment.

[0025] [Figure 17] 1 illustrates an example of a wireless communication system architecture according to embodiments disclosed herein.

[0026] [Figure 18] 1 illustrates a system for performing signaling between a first wireless device and a second wireless device according to an embodiment disclosed herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Various embodiments are described with respect to a UE. However, reference to a UE is provided for illustrative purposes only. The illustrative embodiments may be used with any electronic component that is capable of establishing a connection to a network and configured with hardware, software, and / or firmware for exchanging information and data with the network. Thus, a UE as described herein is used to represent any suitable electronic component.

[0028] In the embodiments herein, sidelink (SL) communication between two or more UEs is discussed. SL communication as described herein contemplates communication between two or more UEs without the use of an intermediate RAN device such as a base station. For example, SL communication as described herein includes cases where signaling generated by a first UE is received (directly) at a second UE and used by the second UE.

[0029] FIG. 1 illustrates a diagram 100 showing a timeline 102 of SL Synchronization Signal Block (SSB) (S-SSB) transmission by a transmitting (Tx) UE, according to one embodiment. As used herein, the term "Tx UE" may refer to a first UE that transmits one or more S-SSBs to an Rx UE. Correspondingly, as used herein, the term "receiving (Rx) UE" may refer to a second UE that receives one (or more) of these one or more S-SSBs. Tx UEs and Rx UEs that communicate in this manner using one or more S-SSBs may be understood to be "peer UEs" as described herein.

[0030] The S-SSB may be transmitted from the TxUE to the RxUE to enable the RxUE to synchronize itself with the timing used by the TxUE. Since the TxUE is assumed to have synchronized itself to some synchronization source (e.g., a base station, a Global Navigation Satellite System (GNSS), or another UE, as described in more detail herein), the RxUE is thus enabled to be synchronized across a system of UEs that use the same ultimate synchronization source at the TxUE.

[0031] Thus, it will be understood that the TxUE of any TxUE-RxUE pair under discussion may, at least in some embodiments, itself be an RxUE that receives S-SSBs from its own TxUE in the configurations described. Correspondingly, it will be understood that the RxUE of any TxUE-RxUE pair under discussion may, at least in some embodiments, itself be an RxUE that transmits S-SSBs to its own RxUE in the configurations described.

[0032] The TxUE may transmit multiple S-SSBs using the SL communication method during the S-SSB periodicity 116. In some embodiments, the S-SSB periodicity 116 may be 160 milliseconds (ms), as shown in FIG.

[0033] Although the diagram 100 of FIG. 8 corresponds to a timeline 102 in which the TxUE transmits four such S-SSBs (first S-SSB 104, second S-SSB 106, third S-SSB 108, and fourth S-SSB 110) during the S-SSB periodicity 116, it should be understood that the TxUE may transmit another number of S-SSBs (other than four) in other embodiments (as described below).

[0034] The first S-SSB of an S-SSB periodicity may be positioned using a configurable offset relative to the system frame boundary that corresponds to the start of the S-SSB periodicity. For example, FIG. 1 shows that the first S-SSB 104 uses a configurable offset 112 from the start of the S-SSB periodicity 116. Each subsequent S-SSB within that same SSB periodicity may be spaced apart by a configurable interval (which may or may not be the same value as the configurable offset). For example, FIG. 1 shows that the second S-SSB 106, the third S-SSB 108, and the fourth S-SSB 110 within the S-SSB periodicity 116 are each spaced apart by a configurable interval 114 from their preceding S-SSB.

[0035] The total number of S-SSBs that may occur during a single S-SSB periodicity may be configurable at the TxUE. The option for such a configured number of S-SSBs may be understood according to the subcarrier spacing (SCS) and / or frequency range (e.g., FR1, FR2) currently used for SL communication using S-SSB. For example, in FR1, when a 15 kilohertz (kHz) SCS is used, the number of S-SSB transmissions during a single S-SSB periodicity may be configured to be 1, when a 30 kHz SCS is used, the number of S-SSB transmissions during a single S-SSB periodicity may be configured to be 1 or 2, and when a 60 kHz SCS is used, the number of S-SSB transmissions during a single S-SSB periodicity may be configured to be 1, 2, or 4. Furthermore, in FR2, if a 60 kHz SCS is used, the number of S-SSB transmissions during a single S-SSB periodicity can be configured to be 1, 2, 4, 8, 16, or 32, and if a 120 kHz SCS is used, the number of S-SSB transmissions during a single S-SSB periodicity can be configured to be 1, 2, 4, 8, 16, 32, or 64.

[0036] As used herein, a "set of configured S-SSBs" (sometimes referred to as a "configured S-SSB set" or the like) may refer to S-SSBs configured to correspond to one S-SSB periodicity, as previously described. Thus, for example, it will be understood that the set of configured S-SSBs under discussion represents 64 S-SSBs if the TxUE is configured for 64 S-SSBs at each S-SSB periodicity.

[0037] As shown in the extension of the first S-SSB 104 shown in Figure 1, the S-SSB may potentially have a time domain 118 of 13 symbols. An example is shown in Figure 1, where the first S-SSB 104 is shown using 13 symbols (symbols 0 through 12). The "GAP" shown at symbol 13 of the first S-SSB 104 may correspond to an intentional non-use of symbol 13 for SL by the TxUE according to the SL slot arrangement being used. The illustrated case may correspond to the use of a normal cyclic prefix (CP) for S-SSB transmissions.

[0038] In other cases, the S-SSB may instead have a time domain of 11 symbols, which case may correspond to the use of an extended CP for S-SSB transmission.

[0039] Further, as illustrated in FIG. 1, an S-SSB may have a frequency region 120 of 11 physical resource blocks (PRBs).

[0040] The S-SSB may include a Physical Sidelink Broadcast Channel (PSBCH) that is used to communicate some data (e.g., SL Master Information Block (MIB) (SL-MIB) data) between the TxUE transmitting the S-SSB and the RxUE receiving the S-SSB. The expanded view of the first S-SSB 104 in Figure 1 shows that the first S-SSB 104 includes a PSBCH in slots 0 and 5 through 12.

[0041] The S-SSB may further include a Sidelink Primary Synchronization Signal (S-PSS) and a Sidelink Secondary Synchronization Signal (S-SSS). The expanded view of the first S-SSB 104 in Figure 1 shows that the first S-SSB 104 includes an S-PSS in slots 1 and 2, and an S-SSS in slots 3 and 4.

[0042] The S-PSS and S-SSS of the S-SSB may be used together to represent a Sidelink Synchronization Identity (SSID) of the S-SSB. In some wireless communication systems, it may be possible for an S-SSB to correspond to one of 672 different SSIDs (indexed from 0 to 671). The S-PSS may indicate which half of the 672 SSIDs includes the S-SSB's SSID (e.g., a value of 0 indicates that the S-SSB has SSIDs with indexes ranging from 0 to 335, a value of 1 indicates that the S-SSB has SSIDs with indexes ranging from 336 to 671). And, the S-SSS may include a subindex (between 0 and 335) that indicates the particular SSID of the half identified by the S-PSS that is the SSID of the S-SSB.

[0043] The SSID may be used to indicate synchronization information for the TxUE transmitting the S-SSB to the receiving RxUE. An SSID index of 0 may indicate to the RxUE that the S-SSB is from a TxUE that is synchronized to a GNSS (e.g., Global Positioning System (GPS), Global Navigation Satellite System (GLONASS)) via direct signaling with the GNSS. An SSID index in the range of 1 to 335 may indicate to the RxUE that the S-SSB is from a TxUE that derived its synchronization via direct synchronization with a base station, or from another UE that derives its synchronization via direct synchronization with a base station. An SSID index of 336 or 337 may indicate to the RxUE that the TxUE is indirectly synchronized to a GNSS (e.g., via another UE that is synchronized to the GNSS). An SSID index in the range of 336 to 671 may indicate to the RxUE that the TxUE is out of coverage and has derived its synchronization from another UE that is also out of coverage.

[0044] In some circumstances, it may be beneficial to extend the S-SSB use design as described in relation to FIG.

[0045] For example, for SL communications between handheld UEs, if long distances (e.g., 2 kilometers (km) or more) need to be covered in frequency bands below 1 gigahertz (GHz), the maximum coupling loss requirement may approach or exceed 160 decibels (dB). Such requirements may not be met when using the S-SSB scheme of FIG. 1.

[0046] Furthermore, in some cases, it may be desirable for SL communications to be carried out within a frequency spectrum that is not licensed by a relevant jurisdiction, but is open by that jurisdiction for use by many different wireless devices according to a pre-arranged set of rules. In such cases, the rules governing the use of this spectrum may require Clear Channel Assessment (CCA) / Listen Before Talk (LBT) to be performed by wireless devices (e.g., UEs) transmitting within this spectrum. The requirement to use CCA / LBT may interfere with the implicit assumption of the S-SSB use design of FIG. 1 for SSB transmissions with known periodicity. Furthermore, the rules for unlicensed spectrum may include spectral density restrictions that may preclude the use of the S-SSB use design of FIG. 1.

[0047] Therefore, for these and other reasons, various modifications and extensions to the design and / or use of S-SSB (as compared to that described in connection with FIG. 1) are contemplated herein to extend the use of S-SSB to situations where the usage model described in connection with FIG. 1 is insufficient or otherwise less desirable.

[0048] Embodiments for S-SSB Frequency Domain Extension

[0049] It is contemplated that one or more embodiments for S-SSB frequency domain extensions as discussed herein may be combined with other embodiments for S-SSB extensions described herein.

[0050] 2 illustrates a frequency hopping pattern 200 used for S-SSB transmissions, according to one embodiment. As illustrated, the S-SSBs 202 being transmitted by the TxUE may be arranged according to a frequency hopping pattern, such that one of the S-SSBs 202 (e.g., within the same S-SSB periodicity) is sent using a different PRB set (e.g., unlike timeline 102 of FIG. 1, each of the first S-SSB 104, second S-SSB 106, third S-SSB 108, and fourth S-SSB 110 is sent using the same set of PRBs).

[0051] This frequency hopping behavior may enable the TxUE to transmit S-SSB signaling in licensed and unlicensed bands. For example, the frequency hopping behavior applied to S-SSB 202 may cause the entire frequency range 204 used by S-SSB 202 to meet minimum frequency occupancy requirements imposed by regulations regarding the use of frequency bands in the unlicensed spectrum.

[0052] Furthermore, the frequency hopping behavior may enable the use of additional SSIDs between the TxUE and the RxUE (e.g., beyond 672 as described above in connection with FIG. 1). For example, a first frequency hopping pattern (e.g., as shown in FIG. 1) may be associated with a first set of SSIDs (e.g., 672, or some other number), and a second frequency hopping pattern (e.g., other than that shown in FIG. 1) may be associated with a second set of different SSIDs (e.g., 672, or some other number). Thus, the TxUE may communicate to the RxUE the grouping of SSIDs associated with the transmitted S-SSB according to the frequency hopping pattern used, where the particular SSID (within that grouping) of one or more of the S-SSBs may be determined, for example, by using the S-PSS and S-SSS of each of the S-SSBs in a manner similar to that described in connection with FIG. 1.

[0053] The frequency hopping behavior may also be used as a mechanism for distinguishing between pairs of SL UEs and UEs. For example, a first pair of UEs (e.g., using the same SL resource pool) may use a first frequency hopping pattern (e.g., frequency hopping pattern 200) for S-SSB transmissions, and a second pair of UEs may use a second frequency hopping pattern (e.g., a frequency hopping pattern other than frequency hopping pattern 200) for S-SSB transmissions. In this way, the first and second pairs of UEs may experience reduced interference when the same frequency range 204 (or overlapping frequency ranges) are used for their respective S-SSB transmission behaviors.

[0054] The frequency hopping behavior may also allow each individual S-SSB to be sent at a higher power (as opposed to the case in FIG. 1 ) without violating maximum power spectral density (PSD) usage requirements, as the higher power used for each S-SSB is improved over the extended frequency range 204 (e.g., as opposed to the case in FIG. 1 , where each S-SSB is transmitted using the same 11 PRBs).

[0055] In some embodiments, S-SSB frequency domain usage extension may be performed by increasing the number of PRBs that may be occupied by an individual S-SSB (e.g., compared to the case of FIG. 1 where an S-SSB occupies 11 PRBs). This may be done by increasing the sequence length (e.g., m sequence length) of the S-SSS and / or S-PSS of the S-SSB (e.g., to a larger prime number). In some embodiments, a sequence length of 257 may be used such that an individual S-SSB uses 24 PRBs. In some embodiments, a sequence length of 383 may be used such that an individual S-SSB uses 36 PRBs. In some embodiments, a sequence length of 509 may be used such that an individual S-SSB uses 48 PRBs. In some embodiments, a sequence length of 773 may be used such that an individual S-SSB uses 72 PRBs. In some embodiments, a sequence length of 1033 may be used such that an individual S-SSB uses 96 PRBs. Other possible sequence length / PRB size arrangements are contemplated.

[0056] This S-SSB frequency occupancy extension may enable the use of S-SSB signaling in unlicensed bands by the TxUE, for example, the S-SSB frequency occupancy extension behavior applied to S-SSB may make the entire frequency range used by S-SSB meet the minimum frequency occupancy requirements imposed by the regulations regarding the use of frequency bands in unlicensed spectrum.

[0057] This S-SSB frequency occupancy extension may also allow each individual S-SSB to be sent at higher power (as opposed to the case in FIG. 1 ) without violating the maximum PSD usage requirement, since the higher power used for each S-SSB is ameliorated by the extended frequency range used by each S-SSB (e.g., as opposed to the case in FIG. 1 , where each S-SSB is transmitted using 11 PRBs).

[0058] 3 illustrates the use of a repeated S-SSB 302 in the frequency domain, according to an embodiment. As illustrated, an S-SSB (e.g., configured as described in connection with FIG. 1) may be repeated in the frequency domain.

[0059] This S-SSB repetition may enable the TxUE to use S-SSB signaling in unlicensed bands, for example, the S-SSB repetition may make the entire frequency range used by the repeated S-SSB 302 meet minimum frequency occupancy requirements imposed by regulations regarding the use of frequency bands in unlicensed spectrum.

[0060] 4 illustrates a method 400 for a UE for SL communication according to one embodiment. The method 400 includes selecting 402 a first S-SSB frequency hopping pattern.

[0061] The method 400 further includes transmitting 404 the first plurality of S-SSBs to the first peer UE according to the first S-SSB frequency hopping pattern.

[0062] In some embodiments of the method 400, the SSID used by the first plurality of S-SSBs corresponds to a first frequency hopping pattern.

[0063] In some embodiments, the method 400 further includes selecting a second S-SSB frequency hopping pattern and transmitting the second plurality of S-SSBs to the second peer UE according to the second frequency hopping pattern. In some of these embodiments, a first synchronization signal identifier (SSID) used by the first plurality of S-SSBs corresponds to the first frequency hopping pattern and a second SSID used by the second plurality of S-SSBs corresponds to the second frequency hopping pattern.

[0064] In some embodiments of method 400, the SL communication uses a subcarrier spacing of greater than or equal to 15 kilohertz (kHz) and less than or equal to 60 kHz, and the SL communication includes transmitting 64 or more configured S-SSBs within one period of the S-SSB periodicity.

[0065] In some embodiments of method 400, the SL communication uses a subcarrier spacing of greater than or equal to 15 kilohertz (kHz) and less than or equal to 120 kHz, and the SL communication includes transmitting 128 or more configured S-SSBs within one period of the S-SSB periodicity.

[0066] In some embodiments, the method 400 further includes performing a CCA on the carrier to be used by the UE for the S-SSB transmission and performing the S-SSB transmission after completion of the CCA. In some of these embodiments, the method 1600 further includes including an indication of an amount of transmission delay imposed on the S-SSB transmission due to the CCA relative to a configured transmit timing for the S-SSB transmission.

[0067] In some embodiments, the method 400 further includes identifying to the peer UE one or more configured S-SSBs of the set of configured S-SSBs. In some of these embodiments, the one or more configured S-SSBs are identified to the peer UE using a bitmap, where each bit of the bitmap corresponds to one of the set of configured S-SSBs. In some of these embodiments, the one or more configured S-SSBs are identified to the peer UE using a first bitmap and a second bitmap, where the first bitmap identifies segments of the set of configured S-SSBs that include one or more of the configured S-SSBs, and the second bitmap identifies one or more of the configured S-SSBs within each segment.

[0068] 5 illustrates a method 500 for a UE for SL communication according to one embodiment. The method 500 includes transmitting 502 a plurality of S-SSBs in a frequency region greater than 11 PRBs.

[0069] In some embodiments of the method 500, each of the plurality of S-SSBs includes more than 11 PRBs.

[0070] In some embodiments of the method 500, the multiple S-SSBs include repeated S-SSBs in the frequency domain.

[0071] In some embodiments of method 500, the SL communication uses subcarrier spacing of greater than or equal to 15 kHz and less than or equal to 60 kHz, and the SL communication includes transmitting 64 or more configured S-SSBs within one period of the S-SSB periodicity.

[0072] In some embodiments of method 500, the SL communication uses subcarrier spacing of greater than or equal to 15 kHz and less than or equal to 120 kHz, and the SL communication includes transmitting 128 or more configured S-SSBs within one period of the S-SSB periodicity.

[0073] In some embodiments, the method 500 further includes performing a CCA on the carrier to be used by the UE for the S-SSB transmission and performing the S-SSB transmission after completion of the CCA. In some of these embodiments, the method 1600 further includes including an indication of an amount of transmission delay imposed on the S-SSB transmission due to the CCA relative to a configured transmit timing for the S-SSB transmission.

[0074] In some embodiments, the method 500 further includes identifying to the peer UE one or more configured S-SSBs of the set of configured S-SSBs. In some of these embodiments, the one or more configured S-SSBs are identified to the peer UE using a bitmap, where each bit of the bitmap corresponds to one of the set of configured S-SSBs. In some of these embodiments, the one or more configured S-SSBs are identified to the peer UE using a first bitmap and a second bitmap, where the first bitmap identifies segments of the set of configured S-SSBs that include one or more of the configured S-SSBs, and the second bitmap identifies one or more of the configured S-SSBs within each segment.

[0075] Embodiments contemplated herein include an apparatus comprising means for performing one or more elements of method 400 or method 500. The apparatus may be, for example, an apparatus of a UE (such as one of the first wireless device 1802 or the second wireless device 1818 that is a UE as described herein).

[0076] Embodiments contemplated herein include one or more non-transitory computer-readable media containing instructions that, when executed by one or more processors of the electronic device, cause the electronic device to perform one or more elements of the methods 400 or 500. The non-transitory computer-readable medium may be, for example, a memory of a UE (such as memory 1806 or memory 1822 of one of the first wireless device 1802 or second wireless device 1818, which are UEs as described herein).

[0077] Embodiments contemplated herein include an apparatus comprising logic, modules, or circuitry for performing one or more elements of method 400 or method 500. The apparatus may be, for example, an apparatus of a UE (such as one of the first wireless device 1802 or the second wireless device 1818 that is a UE as described herein).

[0078] Embodiments contemplated herein include an apparatus comprising one or more processors and one or more computer-readable media containing instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more elements of method 400 or method 500. The apparatus may be, for example, an apparatus of a UE (such as one of the first wireless device 1802 or the second wireless device 1818 that is a UE as described herein).

[0079] Embodiments contemplated herein include signals described or associated with one or more elements of method 400 or method 500.

[0080] Embodiments contemplated herein include a computer program or computer program product including instructions, the execution of which by a processor causes the processor to perform one or more elements of method 400 or 500. The processor may be a processor of a UE (such as processor 1804 or processor 1820 of one of the first wireless device 1802 or second wireless device 1818 that is a UE, as described herein). The instructions may be located, for example, in a processor and / or memory of the UE (such as memory 1806 or memory 1822 of one of the first wireless device 1802 or second wireless device 1818 that is a UE, as described herein).

[0081] Embodiments for S-SSB Time Domain Extension

[0082] It is contemplated that one or more embodiments for S-SSB time domain extensions as discussed herein may be combined with other embodiments for S-SSB extensions described herein.

[0083] In some cases of S-SSB time domain extension, the S-SSB periodicity used may be relatively small (e.g., compared to the 160 ms case shown in connection with FIG. 1). For example, the S-SSB periodicity used may be one of 5 ms, 10 ms, 20 ms, 40 ms, 80 ms, or some other value less than 160 ms. This value may be configured (e.g., at the TxUE by the base station) using the "SL-SyncConfig" information element (IE).

[0084] A relative reduction in S-SSB periodicity causes the corresponding configured set of S-SSBs to be transmitted relatively frequently. Thus, the RxUE has additional opportunities to receive one or more S-SSBs of the S-SSB configured set used during these (smaller) periodicities, as opposed to the case of a relatively long S-SSB periodicity. This may allow the RxUE, for example, to synchronize to the TxUE more quickly than would otherwise be the case, and / or to verify and / or correct synchronization with the TxUE more frequently (improving overall synchronization accuracy).

[0085] 6 illustrates a method 600 for S-SSB time domain extension according to one embodiment. The method 600 includes transmitting 602 a plurality of S-SSBs according to an S-SSB periodicity of less than 160 ms.

[0086] In some embodiments of the method 600, the S-SSB periodicity used may be one of 5 ms, 10 ms, 20 ms, 40 ms, 80 ms, or some other value less than 160 ms.

[0087] In some embodiments of the method 600, the S-SSB periodicity may be configured using an additional information element in the "SL-SyncConfig" IE.

[0088] In some cases of S-SSB time domain extensions, regardless of the frequency range (e.g., FR1, FR2, etc.) and / or SCS used, a TxUE may be configured to transmit up to 64, 128 or 256 (or some other number, e.g., greater than 256) configured S-SSBs during a single S-SSB periodicity.

[0089] Using a relatively large number of S-SSBs in the set of configured S-SSBs in this manner may be useful when beamforming is applied to the S-SSBs (e.g., such as in the embodiments discussed herein). For example, when beamforming is used on the S-SSBs, a relatively large number of S-SSBs in the set of configured S-SSBs may allow narrower beams to be used by the TxUE while still having a desired coverage density for the entire spatial channel, thereby improving the performance of a subsequent beamformed transmission by the TxUE using one of these (relatively narrow) beams (e.g., as determined using a beam sweep using S-SSB beamforming).

[0090] 7 illustrates a method 700 for S-SSB time domain extension, according to one embodiment. The method 700 includes transmitting 702 64 or more S-SSBs within one cycle of the S-SSB periodicity. For example, the SL communication between the TxUE and the RxUE may use an SCS between 15 kHz and 60 kHz, inclusive, and the TxUE may transmit 64 or more configured S-SSBs within one cycle of the S-SSB periodicity.

[0091] 8 illustrates a method 800 for S-SSB time domain extension, according to one embodiment. The method 800 includes transmitting 128 or more S-SSBs within one cycle of the S-SSB periodicity 802. For example, the SL communication between the TxUE and the RxUE uses an SCS between 15 kHz and 120 kHz, inclusive, and the TxUE can transmit 128 or more configured S-SSBs within one cycle of the S-SSB periodicity.

[0092] In some cases of S-SSB time domain extensions, when using an unlicensed spectrum, the actual S-SSB transmission may be delayed (compared to the time of the otherwise expected S-SSB transmission) due to the use of CCA / LBT procedures required by the regulations to be used in the unlicensed spectrum prior to transmission.

[0093] 9 shows a diagram 900 illustrating a timeline 902 of S-SSB transmission by a TxUE when using CCA / LBT, according to one embodiment. The TxUE is configured to transmit a pair of S-SSBs, a first S-SSB 904 and a second S-SSB 906. A configurable offset 908 may be applied relative to a system frame boundary corresponding to the S-SSB periodicity 912, as described in connection with FIG. 1. Additionally, the first S-SSB 904 and the second S-SSB 906 may be separated by a configurable interval 910, as previously described.

[0094] However, unlike in Fig. 1, the TxUE is shown to perform CCA / LBT on the carriers it intends to use in the CCA / LBT window 914 before transmitting the first S-SSB 904 and the second S-SSB 906. This may comply with regulations for using frequency ranges in unlicensed spectrum, which by regulation require a check on the current usage of the carrier / channel to be used before transmission. As can be seen, the use of the CCA / LBT window 914 may delay the transmission of the first S-SSB 904 and the second S-SSB 906 compared to not using the CCA / LBT window 914 (e.g., as shown in Fig. 1).

[0095] The size of the CCA / LBT window 914 may vary between instances according to the timeline 902, since the CCA / LBT process is completed when the carrier / channel is determined to be clear by the CCA / LBT process, which may vary due to variable use of the channel by other wireless devices. Thus, the expected transmit position for transmitting the first S-SSB (e.g., the first S-SSB 904) relative to the start of the associated period of the S-SSB periodicity 912 may not be known in advance at either the TxUE or the RxUE. Thus, once the CCA / LBT process is completed, before transmitting the S-SSB, the TxUE may code within the MIB of the PSBCH of one or more of the S-SSBs (e.g., for the first S-SSB 904 and / or the second S-SSB 906) the amount of delay imposed on the S-SSB by the use of the CCA / LBT window 914. Thus, when the TxUE receives an S-SSB with this information, the TxUE is able to accordingly take into account the delay imposed on the received S-SSB by the CCA / LBT window 914 when using the received S-SSB to synchronize with the TxUE.

[0096] 10 illustrates a method 1000 for S-SSB time domain extension according to one embodiment. The method 1000 includes performing 1002 CCA or LBT on a carrier to be used by a UE for S-SSB transmission.

[0097] The method 1000 further includes performing 1004 an S-SSB transmission after completion of the CCA or LBT.

[0098] In some embodiments, the method 1000 further includes including, in the S-SSB transmission, an indication of an amount of transmission delay imposed on the S-SSB transmission due to CCA or LBT relative to a configured transmit timing for the S-SSB transmission.

[0099] In some cases of S-SSB time domain extension, only some of the S-SSBs of the configured S-SSB set may actually be sent (e.g., in each of one or more periods of the associated S-SSB periodicity). This may be done to match a time division duplex (TDD) configuration or a duplex direction configuration used between the TxUE and the RxUE. This may also operate to reduce the processing load of the RxUE for hypothesis verification. Transmitting less than the fully configured set of S-SSBs during the S-SSB periodicity may also operate to account for any effective reduction in the available period during the S-SSB periodicity for transmission of S-SSBs due to the use of CCA / LBT windows, as described herein.

[0100] The pattern of the actually transmitted S-SSBs for the set of configured S-SSBs may be configured between the TxUE and the RxUE, or in other words, the TxUE may inform the RxUE of the actually transmitted S-SSBs for the set of configured S-SSBs.

[0101] In the first case, a complete bitmap may be used to represent the actually transmitted S-SSBs of the configured set of S-SSBs. For example, if the configured set of S-SSBs has 64 S-SSBs, a 64-bit bitmap may be used. In some cases, a "1" in the i-th location in the bitmap represents that the i-th S-SSB of the configured set is transmitted, and a "0" in the i-th location in the bitmap represents that the i-th S-SSB of the configured set is not transmitted.

[0102] In the second case, two bitmaps can be used to represent the actually transmitted S-SSBs of the configured set of S-SSBs. For example, if the configured set of S-SSBs has 64 S-SSBs, a bitmap of dimension N and a bitmap of dimension M can be used, where N is the number of S-SSBs that are actually transmitted. *M=64. In such a case, the total number of S-SSBs (e.g., 64) may be divided into M segments, with each segment having N S-SSBs. Then, a "1" in the i-th bit of bitmap M represents that the i-th segment of the M segments has one or more S-SSBs to be actually transmitted. Furthermore, a "1" in the i-th bit of bitmap N represents that the i-th individual S-SSB in each segment previously indicated in bitmap M is to be transmitted.

[0103] As will be appreciated with reference to the above description, the second case can ultimately use fewer total bits (N+M bits) as opposed to the first case (which uses a full 1:1 bitmap for the complete set of configured S-SSBs). For example, take again the case of a configured set of S-SSBs that includes 64 S-SSBs. In the first case, a 64-bit bitmap can be used to represent all 64 S-SSBs on a 1:1 basis. The second case can instead use N=8 and M=8 (8 * 8=64), so bitmaps N and M together may require only 8+8=16 bits.

[0104] In either case, once generated, the bitmap can be signaled from the TxUE to the RxUE. This can occur after the TxUE and RxUE have an initial communication path (over the SL and / or over the RAN in case of pre-configuration or configuration of the SL transmission manner by the base station). Thus, the bitmap can be sent in RRC messages, system information messages, medium access control elements (MAC CE), uplink signaling, downlink control information (DCI), and / or sidelink control information (SCI) in various cases.

[0105] 11 illustrates a method 1100 for S-SSB time domain extension according to one embodiment. The method 1100 includes selecting 1102 one or more configured S-SSBs for transmission to a peer UE corresponding to a set of configured S-SSBs.

[0106] The method 1100 further includes identifying 1104 one or more configured S-SSBs for the peer UE.

[0107] The method 1100 further includes transmitting 1106 the one or more configured S-SSBs to the peer UE.

[0108] In some embodiments of the method 1100, the one or more configured S-SSBs are identified to the peer UE using a bitmap, with each bit in the bitmap corresponding to one of the set of configured S-SSBs.

[0109] In some embodiments of method 1100, the first bitmap identifies segments of the set of configured S-SSBs that include one or more of the configured S-SSBs, and the second bitmap identifies one or more of the configured S-SSBs within each segment.

[0110] Embodiments contemplated herein include an apparatus comprising means for performing one or more elements of method 600, method 700, method 800, method 1000, or method 1100. The apparatus may be, for example, an apparatus of a UE (such as one of the first wireless device 1802 or the second wireless device 1818 that is a UE as described herein).

[0111] Embodiments contemplated herein include one or more non-transitory computer-readable media containing instructions that, upon execution by one or more processors of the electronic device, cause the electronic device to perform one or more elements of method 600, method 700, method 800, method 1000, or method 1100. The non-transitory computer-readable medium may be, for example, a memory of a UE (such as memory 1806 or memory 1822 of one of the first wireless device 1802 or second wireless device 1818 that are UEs as described herein).

[0112] Embodiments contemplated herein include an apparatus comprising logic, modules, or circuitry for performing one or more elements of method 600, method 700, method 800, method 1000, or method 1100. The apparatus may be, for example, an apparatus of a UE (such as one of the first wireless device 1802 or the second wireless device 1818 that is a UE as described herein).

[0113] Embodiments contemplated herein include an apparatus comprising one or more processors and one or more computer-readable media containing instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more elements of method 600, method 700, method 800, method 1000, or method 1100. The apparatus may be, for example, an apparatus of a UE (such as one of the first wireless device 1802 or the second wireless device 1818 that is a UE as described herein).

[0114] Embodiments contemplated herein include signals described in or associated with one or more elements of method 600 , method 700 , method 800 , method 1000 , or method 1100 .

[0115] Embodiments contemplated herein include a computer program or computer program product including instructions, where execution of the program by a processor causes the processor to perform one or more elements of method 600, method 700, method 800, method 1000, or method 1100. The processor may be a processor of a UE (such as processor 1804 or processor 1820 of one of the first wireless device 1802 or second wireless device 1818 that is a UE, as described herein). The instructions may be located, for example, in a processor and / or memory of the UE (such as memory 1806 or memory 1822 of one of the first wireless device 1802 or second wireless device 1818 that is a UE, as described herein). Multi-beam S-SSB extension embodiment

[0116] It is contemplated that one or more of the embodiments for multibeam S-SSB extensions described herein can be combined with other embodiments for S-SSB extensions described herein.

[0117] FIG. 12 shows a diagram 1200 illustrating transmission of S-SSBs in a beamforming manner by a TxUE, according to one embodiment. The network (e.g., via a base station) may dynamically signal, configure, or pre-configure the TxUE with an index corresponding to a set of configured S-SSBs. In the example of FIG. 12, a first S-SSB 1202 is assigned index 0, a second S-SSB 1204 is assigned index 1, a third S-SSB 1206 is assigned index 2, and a fourth S-SSB 1208 is assigned index 3.

[0118] The TxUE may understand different indices for the S-SSBs to correspond to the different beamformings that the S-SSBs should be sent in. For example, a first S-SSB 1202 is sent using a first beamforming 1210 (corresponding to index 0), a second S-SSB 1204 is sent using a second beamforming 1212 (corresponding to index 1), a third S-SSB 1206 is sent using a third beamforming 1214 (corresponding to index 2), and a fourth S-SSB 1208 is sent using a fourth beamforming 1216 (corresponding to index 3).

[0119] Although not illustrated here, it is contemplated that different S-SSBs within a set of configured S-SSBs may be assigned the same index (and therefore may use the same beamforming).

[0120] The S-SSB may indicate the assigned index to the RxUE. In the first case, the S-SSB may implicitly indicate its index to the RxUE based on the transmission timing of the S-SSB. This type of indication may be used if the RxUE receives all of the S-SSBs in the configured set.

[0121] In the second case, the S-SSB may indicate its index within its PSBCH payload (eg, within the MIB of its PSBCH payload).

[0122] In the third case, the S-SSB may indicate a first portion of its index using its PSFCH payload. For example, the most significant bits (MSBs) or least significant bits (LSBs) of a value representing its index may be included in its PSFCH payload. The S-SSB may further indicate a second portion of its index using PSBCH payload scrambling, cyclic redundancy check (CRC) scrambling, and / or PSBCH demodulation reference signal (DMRS) generation (e.g., if the particular nature of the PSBCH payload scrambling, the particular nature of the CRC scrambling, and / or the location of the PSBCH DMRS used by the S-SSB indicates the remaining bits of the value representing its index).

[0123] In the fourth case, a new symbol and / or sequence is used by the S-SSB to indicate its index.

[0124] When transmitting an S-SSB using a multi-beam extension method (e.g., as described herein), the TxUE can ensure that within the S-SSB, all symbols / channels (e.g., S-PSS, S-SSS, and PSBCH) are transmitted with the same Doppler spread, Doppler shift, average delay, delay spread, and, if applicable, spatial Rx parameters, ensuring that the components of each individual S-SSB are consistent with each other on the transmission channel.

[0125] Furthermore, within a single period of S-SSB periodicity, the TxUE may ensure that all transmitted S-SSBs are transmitted with the same amount of power, ensuring that the Reference Signal Received Power (RSRP) and / or Signal to Interference and Noise Ratio (SINR) of S-SSBs measured at the TxUE with the same S-SSB periodicity can be usefully compared at the TxUE.

[0126] Additionally, the TxUE may ensure that the S-SSB corresponding to the same index (e.g., over multiple periods of the S-SSB periodicity) is transmitted with the same Doppler spread, Doppler shift, average delay, delay spread, spatial Rx parameters (if applicable), and / or transmit power, so that, for example, changes over time to the measured RSRP / SINR of the S-SSB received on the beam corresponding to that index can be usefully analyzed by the TxUE.

[0127] It should be noted that by operating within these constraints as described (with respect to Doppler spread, the same Doppler shift, average delay, delay spread, spatial Rx parameters (if applicable), and / or transmit power levels as described), the S-SSB may be used by the Rx UE as one or more of a reference signal for quasi-co-location (QCL) purposes (e.g., including QCL-Type A, QCL-Type B, QCL-Type C, and / or QCL-Type D), a reference signal for path loss estimation purposes, a reference signal for radio link monitoring (RLM) purposes, a reference signal for beam failure detection (BFD) purposes, and / or a reference signal for candidate beam detection (CBD) purposes.

[0128] It should be noted that in other embodiments using the multi-beam S-SSB extensions described herein, it is contemplated that the base station may take the place of the TxUE as described (and may use SL signaling rather than Uu signaling as explained).

[0129] 13 illustrates a method 1300 of a UE for SL communication according to one embodiment. The method 1300 includes receiving 1302, from a second UE, one or more indices corresponding to a configured set of SL synchronization signal blocks (S-SSBs); and

[0130] The method 1300 further includes receiving 1304 one or more S-SSBs from the second UE, each indicating a corresponding index of the one or more indexes in accordance with a correspondence of the S-SSB to the set of configured S-SSBs, where the one or more S-SSBs are transmitted by the second UE in accordance with beamforming corresponding to their corresponding indexes.

[0131] In some embodiments of the method 1300, the S-SSBs implicitly indicate their corresponding index based on their transmission timing.

[0132] In some embodiments of the method 1300, the S-SSBs indicate their corresponding index in the PSBCH payload.

[0133] In some embodiments of method 1300, the S-SSBs indicate a first portion of their corresponding index in the PSBCH payload and the S-SSBs indicate a second portion of their corresponding index using one of PSBCH scrambling, CRC scrambling, and the location of the PSBCH DMRS in the S-SSB.

[0134] In some embodiments of the method 1300, the S-SSBs indicate their corresponding indexes using sequences found in the S-SSBs.

[0135] In some embodiments of method 1300, each of the S-SSBs transmits each of its symbols according to one or more of the same Doppler spread, the same Doppler shift, the same average delay, the same delay spread, and the same spatial Rx parameters.

[0136] In some embodiments of the method 1300, each of the S-SSBs is transmitted at the same power.

[0137] In some embodiments of method 1300, an S-SSB of an S-SSB that indicates the same corresponding index as an S-SSB prior to the S-SSB is transmitted according to one or more of the same Doppler spread used to transmit the previous S-SSB, the same Doppler shift used to transmit the previous S-SSB, the same average delay used to transmit the previous S-SSB, the same delay spread used to transmit the previous S-SSB, the same spatial Rx parameters used to transmit the previous S-SSB, and the same power used to transmit the previous S-SSB.

[0138] In some embodiments of method 1300, one or more of the S-SSBs are configured to be used for one or more of a reference signal for quasi-collocation, a reference signal for path loss estimation, a reference signal for RLM, a reference signal for BFD, and a reference signal for CBD.

[0139] In some embodiments of method 1300, the SL communication uses subcarrier spacing of greater than or equal to 15 kHz and less than or equal to 60 kHz, and the SL communication includes transmitting 64 or more configured S-SSBs within one period of the S-SSB periodicity.

[0140] In some embodiments of method 1300, the SL communication uses subcarrier spacing of greater than or equal to 15 kHz and less than or equal to 120 kHz, and the SL communication includes transmitting 128 or more configured S-SSBs within one period of the S-SSB periodicity.

[0141] In some embodiments, the method 1300 further includes performing a CCA on the carrier to be used by the UE for the S-SSB transmission and performing the S-SSB transmission after completion of the CCA. In some of these embodiments, the method 1600 further includes including an indication of an amount of transmission delay imposed on the S-SSB transmission due to the CCA relative to a configured transmit timing for the S-SSB transmission.

[0142] In some embodiments, the method 1300 further includes identifying to the peer UE one or more configured S-SSBs of the set of configured S-SSBs. In some of these embodiments, the one or more configured S-SSBs are identified to the peer UE using a bitmap, where each bit of the bitmap corresponds to one of the set of configured S-SSBs. In some of these embodiments, the one or more configured S-SSBs are identified to the peer UE using a first bitmap and a second bitmap, where the first bitmap identifies segments of the set of configured S-SSBs that include one or more of the configured S-SSBs, and the second bitmap identifies one or more of the configured S-SSBs within each segment.

[0143] Embodiments contemplated herein include an apparatus comprising means for performing one or more elements of the method 1300. The apparatus may be, for example, a device of a UE (such as one of the first wireless device 1802 or the second wireless device 1818 that is a UE as described herein).

[0144] Embodiments contemplated herein include one or more non-transitory computer-readable media containing instructions that, when executed by one or more processors of the electronic device, cause the electronic device to perform one or more elements of the method 1300. The non-transitory computer-readable medium may be, for example, a memory of a UE (such as memory 1806 or memory 1822 of one of the first wireless device 1802 or second wireless device 1818 that are UEs as described herein).

[0145] Embodiments contemplated herein include an apparatus comprising logic, modules, or circuitry to perform one or more elements of the method 1300. The apparatus may be, for example, an apparatus of a UE (such as one of the first wireless device 1802 or the second wireless device 1818 that is a UE as described herein).

[0146] Embodiments contemplated herein include an apparatus comprising one or more processors and one or more computer-readable media containing instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more elements of the method 1300. The apparatus may be, for example, an apparatus of a UE (such as one of the first wireless device 1802 or the second wireless device 1818 that is a UE as described herein).

[0147] Embodiments contemplated herein include signals described in or associated with one or more elements of method 1300.

[0148] Embodiments contemplated herein include a computer program or computer program product including instructions, the execution of which by a processor causes the processor to perform one or more elements of the method 1300. The processor may be a processor of a UE (such as the processor 1804 or processor 1820 of one of the first wireless device 1802 or the second wireless device 1818 that is a UE, as described herein). The instructions may be located, for example, in a processor and / or memory of the UE (such as the memory 1806 or memory 1822 of one of the first wireless device 1802 or the second wireless device 1818 that is a UE, as described herein). Embodiments of S-SSB extensions using frequency domain masking and / or time domain masking

[0149] It is contemplated that one or more of the embodiments for S-SSB extensions using frequency domain masking and / or time domain masking described herein may be combined with other embodiments for S-SSB extensions described herein.

[0150] Frequency domain masking may be used to allow the transmitted S-SSB to achieve higher frequency estimation accuracy and to allow the transmitted S-SSB to achieve higher coverage when there are maximum transmit spectral density adjustment requirements applicable to some or all of the bandwidth used for S-SSB transmission.

[0151] In a first option for performing frequency domain masking, blocks of S-SSB entries in the frequency domain (e.g., entries of the transmitted sequence of S-SSB) are used to transmit the S-SSB. Each block of entries includes all the entries of the transmitted sequence of S-SSB, and each block of entries is masked by a different mask of the masking sequence. Thus, the number of blocks of entries may be equal to the number of masks of the masking sequence.

[0152] In a second option for performing frequency domain masking, one or more blocks of entries of the S-SSB in the frequency domain are used, where each block of entries includes a repetition of one entry of the transmitted sequence of the S-SSB. Each such repetition of an entry in a block is masked by a different element of the masking sequence. Thus, the number of one or more blocks of entries may be equal to the number of entries in the transmitted sequence of the S-SSB.

[0153] 14 illustrates a diagram 1400 corresponding to a first option 1402 and a second option 1404 for performing frequency domain masking, according to one embodiment. The diagram 1400 corresponds to the case where the S-SSB 1406 is configured to use 127 entries (denoted 0 through 126) and the masking sequence 1408 includes four masks (e.g., in the form of cover codes and / or phase shift values) used to mask each entry of the S-SSB 1406, denoted m0, m1, m2, and m4. It should be noted that the use of 127 entries for the transmitted sequence of the S-SSB 1406 and the four masks of the masking sequence 1408 is provided by way of example and not limitation. In other embodiments, the S-SSB may use fewer or more than 127 entries in the transmitted sequence and / or the masking sequence used may include fewer or more than four masks.

[0154] According to either the first option 1402 or the second option 1404, each entry of the transmitted sequence of S-SSB 1406 may be transmitted a total of four times in the frequency domain, with each transmission of the same entry using a different mask of the masking sequence 1408, as described in more detail below.

[0155] In the first option 1402, four repeat entry blocks in the frequency domain are used: a first repeat entry block 1410, a second repeat entry block 1412, a third repeat entry block 1414, and a fourth repeat entry block 1416. Each repeat block of entries 1410, 1412, 1414, and 1416 contains all the entries of a transmitted sequence of S-SSBs (e.g., each repeat block of S-SSBs 1410, 1412, 1414, and 1416 contains all such entries of S-SSB 1406). Finally, each repeat block of entries 1410, 1412, 1414, and 1416 is masked by a different element of the masking sequence 1408 (e.g., the entries in the first repeat block 1410 are each masked by m0, the entries in the second repeat block 1412 are each masked by m1, the entries in the third repeat entry block 1414 are each masked by m2, and the entries in the fourth repeat entry block 1416 are each masked by m3).

[0156] In the second option 1404, 127 entry blocks in the frequency domain are used (e.g., from the first entry block 1418 to the 127th entry block 1420, with intermediate blocks represented by ellipses in the second option 1404). Each block of entries contains a repetition of one entry of the transmitted sequence of S-SSB 1406. Furthermore, each entry repetition of that entry (within the block) is masked by a different element of the masking sequence 1408.

[0157] A time-domain repetition for the S-SSBs of the set of configured S-SSBs may be used. The masking sequence used for such S-SSB repetition may include one or more masks. Then, one or more S-SSBs (up to and including all) of the set of configured S-SSBs are (respectively) repeated over time, with each repetition of the S-SSB being masked by a different mask of the masking sequence.

[0158] In some cases, each mask can have unit energy (e.g., −1 or +1). In some cases, each mask can be complex-valued with unit energy.

[0159] In some cases, each mask (e.g., of multiple masks in a masking sequence) is a positive unit energy value. This may correspond to cases where simple repetition of S-SSB may be desired without changing the physics of the associated transmission as between repetitions.

[0160] In other cases, the mask sequence may be selected to have good autocorrelation to enable more accurate timing acquisition by the RxUE using S-SSB time domain repetition.

[0161] When using time domain repetition, the content of each S-SSB repetition (for the same S-SSB of the configured set) is the same, and further, each such S-SSB repetition is transmitted with the same Doppler spread, the same Doppler shift, the same average gain, the same average delay, the same delay spread, the same spatial Rx parameters (if applicable), and / or the same transmit power.

[0162] Figure 15 shows a diagram 1500 corresponding to time-domain masking, according to one embodiment. The example of Figure 15 assumes a masking sequence 1502 having four masks (denoted m0, m1, m2, and m3), although other embodiments may use fewer or more masks.

[0163] Diagram 1500 further includes an S-SSB 1504, which may correspond to one of a set of configured S-SSBs 1504 to be transmitted. As shown, the actual transmission uses four repetitions of the S-SSB 1504 over time (a first S-SSB repetition 1506, a second S-SSB repetition 1508, a third S-SSB repetition 1510, and a fourth S-SSB repetition 1512). Each such repetition is masked using one of four masked values ​​from masking sequence 1502 (wherein the first S-SSB repetition 1506 is masked with m0, the second S-SSB repetition 1508 is masked with m1, the third S-SSB repetition 1510 is masked with m2, and the fourth S-SSB repetition 1512 is masked with m3).

[0164] Although not shown, it should be noted that another S-SSB corresponding to another S-SSB of the configured S-SSB set (other than S-SSB 1504) may also be later repeated four times using each of the four masks of masking sequence 1502.

[0165] 16 illustrates a method 1600 for a UE for SL communication according to one embodiment. The method 1600 includes transmitting 1602 one or more S-SSBs corresponding to a configured set of S-SSBs using one of a frequency domain masking procedure and a time domain masking procedure.

[0166] In some embodiments of method 1600, the one or more S-SSBs include a first S-SSB transmitted using a frequency domain masking procedure, the first S-SSB including a block of entries of a transmitted sequence of S-SSBs in the frequency domain, each block of transmitted sequence entries including all entries for the transmitted sequence of S-SSBs, and each block of entries being masked by a different element of a masking sequence.

[0167] In some embodiments of the method 1600, the one or more S-SSBs include a first S-SSB transmitted using a frequency domain masking procedure, the first S-SSB including a block of entries of a transmitted sequence of S-SSBs in the frequency domain, each block of entries including repetitions of one entry of the transmitted sequence of S-SSBs, each repetition being masked by a different element of a masking sequence.

[0168] In some embodiments of the method 1600, one or more S-SSBs are transmitted using a time-domain masking procedure, where the one or more S-SSBs include repetitions of the S-SSB corresponding to one of a set of configured S-SSBs in the time domain, each repetition being masked by a different element of a masking sequence. In some of these embodiments, each element of the masking sequence corresponds to a value having unit energy. In some of these embodiments, the elements of the masking sequence are identical. In some of these embodiments, the elements of the masking sequence are configured to have good autocorrelation. In some of these embodiments, each of the repetitions of the S-SSB is sent according to one or more of the same Doppler spread, the same Doppler shift, the same average delay, the same delay spread, and the same spatial Rx parameters.

[0169] In some embodiments of method 1600, the SL communication uses subcarrier spacing of greater than or equal to 15 kHz and less than or equal to 60 kHz, and the SL communication includes transmitting 64 or more configured S-SSBs within one period of the S-SSB periodicity.

[0170] In some embodiments of the method 1600, the SL communication uses a subcarrier spacing of greater than or equal to 15 kHz and less than or equal to 120 kHz, and the SL communication includes transmitting 128 or more configured S-SSBs within one period of the S-SSB periodicity.

[0171] In some embodiments, the method 1600 further includes performing a CCA on the carrier to be used by the UE for the S-SSB transmission and performing the S-SSB transmission after completion of the CCA. In some of these embodiments, the method 1600 further includes including an indication of an amount of transmission delay imposed on the S-SSB transmission due to the CCA relative to a configured transmit timing for the S-SSB transmission.

[0172] In some embodiments, the method 1600 further includes identifying to the peer UE one or more configured S-SSBs of the set of configured S-SSBs. In some of these embodiments, the one or more configured S-SSBs are identified to the peer UE using a bitmap, where each bit of the bitmap corresponds to one of the set of configured S-SSBs. In some of these embodiments, the one or more configured S-SSBs are identified to the peer UE using a first bitmap and a second bitmap, where the first bitmap identifies segments of the set of configured S-SSBs that include one or more of the configured S-SSBs, and the second bitmap identifies one or more of the configured S-SSBs within each segment.

[0173] Embodiments contemplated herein include an apparatus comprising means for performing one or more elements of the method 1600. The apparatus may be, for example, an apparatus of a UE (such as one of the first wireless device 1802 or the second wireless device 1818 that is a UE as described herein).

[0174] Embodiments contemplated herein include one or more non-transitory computer-readable media containing instructions that, when executed by one or more processors of the electronic device, cause the electronic device to perform one or more elements of the method 1600. The non-transitory computer-readable medium may be, for example, a memory of a UE (such as memory 1806 or memory 1822 of one of the first wireless device 1802 or second wireless device 1818, which are UEs as described herein).

[0175] Embodiments contemplated herein include an apparatus comprising logic, modules, or circuitry to perform one or more elements of the method 1600. The apparatus may be, for example, an apparatus of a UE (such as one of the first wireless device 1802 or the second wireless device 1818 that is a UE as described herein).

[0176] Embodiments contemplated herein include an apparatus comprising one or more processors and one or more computer-readable media containing instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more elements of the method 1600. The apparatus may be, for example, an apparatus of a UE (such as one of the first wireless device 1802 or the second wireless device 1818 that is a UE as described herein).

[0177] Embodiments contemplated herein include signals described in or associated with one or more elements of method 1600.

[0178] Embodiments contemplated herein include a computer program or computer program product including instructions, the execution of which by a processor causes the processor to perform one or more elements of the method 1600. The processor may be a processor of a UE (such as the processor 1804 or processor 1820 of one of the first wireless device 1802 or the second wireless device 1818 that is a UE, as described herein). The instructions may be located, for example, in a processor and / or memory of the UE (such as the memory 1806 or memory 1822 of one of the first wireless device 1802 or the second wireless device 1818 that is a UE, as described herein). Exemplary embodiments

[0179] 17 illustrates an example architecture of a wireless communication system 1700 according to an embodiment disclosed herein. The following description is provided for an example wireless communication system 1700 operating in conjunction with an LTE system standard and / or a 5G or NR system standard, as provided by the 3GPP technical specifications.

[0180] 17, the wireless communication system 1700 includes a UE 1702 and a UE 1704 (although any number of UEs may be used). In this example, the UE 1702 and the UE 1704 are shown as smartphones (e.g., handheld touchscreen mobile computing devices capable of connecting to one or more cellular networks), but may comprise any mobile or non-mobile computing devices configured for wireless communication.

[0181] The UE 1702 and the UE 1704 may be configured to be communicatively coupled to the RAN 1706. In an embodiment, the RAN 1706 may be an NG-RAN, an E-UTRAN, etc. The UE 1702 and the UE 1704 utilize connections (or channels) with the RAN 1706 (shown as connection 1708 and connection 1710, respectively), each of which comprises a physical communication interface. The RAN 1706 may include one or more base stations, such as base station 1712 and base station 1714, that facilitate the connections 1708 and 1710.

[0182] In this example, connection 1708 and connection 1710 are air interfaces for enabling such communication coupling and may correspond to a RAT used by RAN 1706, such as, for example, LTE and / or NR.

[0183] In some embodiments, the UE 1702 and the UE 1704 may also directly exchange communication data via the sidelink interface 1716. The UE 1704 is configured to access an access point (shown as AP 1718) via a connection 1720 as shown. As an example, the connection 1720 may include a local wireless connection, such as a connection conforming to any IEEE 802.11 protocol, and the AP 1718 may include a Wi-Fi router. In this example, the AP 1718 may be connected to other networks (e.g., the Internet) without passing through the CN 1724.

[0184] In an embodiment, the UEs 1702 and 1704 may be configured to communicate with each other or with the base stations 1712 and / or 1714 using Orthogonal Frequency Division Multiplexing (OFDM) communication signals over multi-carrier communication channels according to various communication technologies, such as, but not limited to, an Orthogonal Frequency Division Multiple Access (OFDMA) communication technology (e.g., for downlink communications) or a Single Carrier Frequency Division Multiple Access (SC-FDMA) communication technology (e.g., for uplink and ProSe or sidelink communications), and the scope of the embodiments is not limited in this respect. An OFDM signal may include multiple orthogonal subcarriers.

[0185] In some embodiments, all or a portion of the base station 1712 or the base station 1714 may be implemented as one or more software entities executing on a server computer as part of a virtual network. In addition, or in other embodiments, the base station 1712 or the base station 1714 may be configured to communicate with each other via the interface 1722. In an embodiment where the wireless communication system 1700 is an LTE system (e.g., where the CN 1724 is an EPC), the interface 1722 may be an X2 interface. The X2 interface may be defined between two or more base stations (e.g., two or more eNBs, etc.) that connect to the EPC and / or between two eNBs that connect to the EPC. In an embodiment where the wireless communication system 1700 is an NR system (e.g., where the CN 1724 is a 5GC), the interface 1722 may be an Xn interface. The Xn interface may be defined between two or more base stations (e.g., two or more gNBs, etc.) that connect to 5GC, between the base station 1712 (e.g., a gNB) and an eNB that connect to 5GC, and / or between two eNBs (e.g., the CN 1724) that connect to 5GC.

[0186] The RAN 1706 is shown communicatively coupled to the CN 1724. The CN 1724 may comprise one or more network elements 1726 configured to provide various data and telecommunication services to customers / subscribers (e.g., users of the UEs 1702 and 1704) connected to the CN 1724 via the RAN 1706. The components of the CN 1724 may be implemented in one physical device or separate physical devices, including components for reading and executing instructions from a machine-readable medium or computer-readable medium (e.g., a non-transitory machine-readable storage medium).

[0187] In an embodiment, the CN 1724 may be an EPC, and the RAN 1706 may be connected to the CN 1724 via an S1 interface 1728. In an embodiment, the S1 interface 1728 may be split into two parts: an S1 user plane (S1-U) interface that carries traffic data between the base station 1712 or base station 1714 and a serving gateway (S-GW), and an S1-MME interface that is a signaling interface between the base station 1712 or base station 1714 and a mobility management entity (MME).

[0188] In an embodiment, the CN 1724 may be a 5GC, and the RAN 1706 may be connected to the CN 1724 via an NG interface 1728. In an embodiment, the NG interface 1728 may be divided into two parts: an NG-User Plane (NG-U) interface, which carries traffic data between the base station 1712 or 1714 and a User Plane Function (UPF), and an S1-Control Plane (NG-C) interface, which is a signaling interface between the base station 1712 or 1714 and an Access and Mobility Management Function (AMF).

[0189] In general, the application server 1730 may be an element that provides applications that use Internet Protocol (IP) bearer resources (e.g., packet-switched data services) with the CN 1724. The application server 1730 may also be configured to support one or more communication services (e.g., VoIP sessions, group communication sessions, etc.) for the UEs 1702 and 1704 via the CN 1724. The application server 1730 may communicate with the CN 1724 via an IP communication interface 1732.

[0190] 18 illustrates a system 1800 for performing signaling 1834 between a first wireless device 1802 and a second wireless device 1818 according to an embodiment disclosed herein. The system 1800 may be part of a wireless communication system as described herein. The first wireless device 1802 may be, for example, a UE of the wireless communication system. The second wireless device 1818 may be, for example, a UE of the wireless communication system. It is also contemplated that in some cases, either the first wireless device 1802 or the second wireless device 1818 may be a base station of the wireless communication system (e.g., using the SL signaling method described herein).

[0191] The first wireless device 1802 may include one or more processors 1804. The processor 1804 may execute instructions such that various operations of the first wireless device 1802 are performed as described herein. The processor 1804 may include, for example, one or more baseband processors implemented using a central processing unit (CPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a controller, a field programmable gate array (FPGA) device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein.

[0192] The wireless device 1802 may include a memory 1806. The memory 1806 may be a non-transitory computer-readable storage medium that stores instructions 1808 (which may include, for example, instructions being executed by the processor 1804). The instructions 1808 may also be referred to as program code or computer programs. The memory 1806 may also store data used by the processor 1804 and results calculated by the processor 1804.

[0193] The first wireless device 1802 may include one or more transceivers 1810, which may include radio frequency (RF) transmitter and / or receiver circuitry that uses an antenna 1812 of the first wireless device 1802 to facilitate signaling (e.g., signaling 1834) between the first wireless device 1802 and other devices (e.g., a second wireless device 1818) in accordance with a corresponding RAT.

[0194] The first wireless device 1802 may include one or more antennas 1812 (e.g., one, two, four, or more). For embodiments with multiple antennas 1812, the first wireless device 1802 may exploit the spatial diversity of such multiple antennas 1812 to transmit and / or receive multiple different data streams over the same time and frequency resources. This behavior may be referred to, for example, as multiple-input multiple-output (MIMO) behavior (referring to the multiple antennas used at each of the transmitting and receiving devices that enable this aspect). MIMO transmission by the first wireless device 1802 may be achieved according to precoding (or digital beamforming) applied at the first wireless device 1802 that multiplexes the data streams across the antennas 1812 according to known or assumed channel characteristics such that each data stream is received at a desired location in the spatial domain (e.g., the location of the receiver associated with that data stream) with an appropriate signal strength relative to the other streams. Some embodiments may use Single-User MIMO (SU-MIMO) methods (wherein all data streams are directed to a single receiver) and / or Multi-User MIMO (MU-MIMO) methods (wherein individual data streams may be directed to individual (different) receivers in different locations in the spatial domain).

[0195] In a particular embodiment having multiple antennas, the first wireless device 1802 may implement an analog beamforming technique whereby the phases of the signals sent by the antennas 1812 are adjusted relatively so that the (joint) transmissions of the antennas 1812 may be directed (this may be referred to as beam steering).

[0196] The wireless device 1802 may include one or more interfaces 1814. The interfaces 1814 may be used to provide input to or output from the wireless device 1802. For example, a first wireless device 1802 that is a UE may include an interface 1814 such as a microphone, speaker, touch screen, buttons, etc. to enable input and / or output to the UE by a user of the UE. Other interfaces of such a UE may consist of transmitters, receivers, and other circuitry (e.g., other than the transceiver 1810 / antenna 1812 already described) to enable communication between the UE and other devices and may operate according to known protocols (e.g., Wi-Fi, Bluetooth, etc.).

[0197] The first wireless device 1802 may include a sidelink module 1816. The sidelink module 1816 may be implemented via hardware, software, or a combination thereof. For example, the sidelink module 1816 may be implemented as a processor, circuitry, and / or instructions 1808 stored in the memory 1806 and executed by the processor 1804. In some examples, the sidelink module 1816 may be integrated within the processor 1804 and / or transceiver 1810. For example, the sidelink module 1816 may be implemented by a combination of software components (e.g., executed by a DSP or general-purpose processor) and hardware components (e.g., logic gates and circuits) within the processor 1804 or transceiver 1810.

[0198] The sidelink module 1816 may be used in various aspects of the disclosure, such as the aspects of FIGS. 1-16. For example, the sidelink module 1816 may be configured to perform procedures for S-SSB frequency domain extension, S-SSB time domain extension, multibeam S-SSB extension, S-SSB extension with frequency domain masking, and / or S-SSB extension with time domain masking, as described herein. The sidelink module 1816 may be configured to perform the functions of one of the TxUE and / or RxUE, as described herein.

[0199] The second wireless device 1818 may include one or more processors 1820. The processor 1820 may execute instructions such that various operations of the second wireless device 1818 are performed, as described herein. The processor 1820 may include, for example, one or more baseband processors implemented using a CPU, a DSP, an ASIC, a controller, an FPGA device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein.

[0200] The second wireless device 1818 may include a memory 1822. The memory 1822 may be a non-transitory computer-readable storage medium that stores instructions 1824 (which may include, for example, instructions being executed by the processor 1820). The instructions 1824 may also be referred to as program code or computer programs. The memory 1822 may also store data used by the processor 1820 and results calculated by the processor 1820.

[0201] The second wireless device 1818 may include one or more transceivers 1826 that may include RF transmitter and / or receiver circuitry that uses an antenna 1828 of the second wireless device 1818 to facilitate signaling (e.g., signaling 1834) between the second wireless device 1818 and other devices (e.g., the first wireless device 1802) in accordance with a corresponding RAT.

[0202] The second wireless device 1818 may include one or more antennas 1828 (e.g., one, two, four, or more). In embodiments having multiple antennas 1828, the second wireless device 1818 may perform MIMO, digital beamforming, analog beamforming, beamsteering, etc., as previously described.

[0203] The second wireless device 1818 may include one or more interfaces 1830. The interfaces 1830 may be used to provide input to or output from the second wireless device 1818. For example, the second wireless device 1818, being a UE, may include interfaces 1830 such as a microphone, speaker, touch screen, buttons, etc., to enable input and / or output to the UE by a user of the UE. Other interfaces of such a UE may consist of transmitters, receivers, and other circuitry (e.g., other than the transceiver 1826 / antenna 1828 already described) to enable communication between the UE and other devices and may operate according to known protocols (e.g., Wi-Fi, Bluetooth, etc.).

[0204] The second wireless device 1818 may include a sidelink module 1832. The sidelink module 1832 may be implemented via hardware, software, or a combination thereof. For example, the sidelink module 1832 may be implemented as a processor, circuitry, and / or instructions 1824 stored in the memory 1822 and executed by the processor 1820. In some examples, the sidelink module 1832 may be integrated within the processor 1820 and / or transceiver 1826. For example, the sidelink module 1832 may be implemented by a combination of software components (e.g., executed by a DSP or general-purpose processor) and hardware components (e.g., logic gates and circuits) within the processor 1820 or transceiver 1826.

[0205] The sidelink module 1832 may be used in various aspects of the disclosure, e.g., the aspects of FIG. 1-16. For example, the sidelink module 1832 may be configured to perform procedures for S-SSB frequency domain extension, S-SSB time domain extension, multibeam S-SSB extension, S-SSB extension with frequency domain masking, and / or S-SSB extension with time domain masking, as described herein. The sidelink module 1832 may be configured to perform functions of one of the TxUE and / or RxUE (e.g., the opposite of the functions currently performed by the sidelink module 1816), as described herein.

[0206] For one or more embodiments, at least one of the components depicted in one or more of the preceding figures may be configured to perform one or more operations, techniques, processes, and / or methods as described herein. For example, a baseband processor as described above in connection with one or more of the figures herein may be configured to operate according to one or more of the examples described herein. As another example, circuitry associated with a UE, a base station, a network element, etc. as described above in connection with one or more of the preceding figures may be configured to operate according to one or more of the examples described herein.

[0207] Any of the above embodiments can be combined with any other embodiment (or combination of embodiments) unless otherwise stated. The foregoing description of one or more implementations provides illustration and description, but is not intended to be exhaustive or to limit the scope of the embodiments to the precise forms disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of various embodiments.

[0208] The embodiments and implementations of the systems and methods described herein may include various operations that may be embodied in machine-executable instructions executed by a computer system. The computer system may include one or more general-purpose or special-purpose computers (or other electronic devices). The computer system may include hardware components that contain specific logic for performing the operations, or may include a combination of hardware, software, and / or firmware.

[0209] It should be appreciated that the systems described herein include descriptions of specific embodiments. These embodiments may be combined into a single system, partially combined into other systems, split into multiple systems, or otherwise split or combined. In addition, it is contemplated that parameters, attributes, aspects, etc. of one embodiment may be used in another embodiment. It is appreciated that parameters, attributes, aspects, etc. are described in one or more embodiments for clarity only, and that parameters, attributes, aspects, etc. may be combined or substituted with parameters, attributes, etc. of another embodiment, unless specifically disclaimed herein.

[0210] It is well understood that use of personal information should comply with privacy policies and practices generally recognized as meeting or exceeding industry or governmental requirements for maintaining user privacy. In particular, personal information data should be managed and handled in a manner that minimizes the risk of unintended or unauthorized access or use, and the nature of authorized uses should be clearly indicated to users.

[0211] Although the foregoing has been described in some detail for clarity, it will be apparent that certain changes and modifications can be made without departing from the principles thereof. It should be noted that there are many alternative ways of implementing both the processes and the apparatus described herein. Thus, the present embodiments should be considered as illustrative and not restrictive, and the description should not be limited to the details given herein, but may be modified within the scope of the appended claims and their equivalents.

Claims

1. 1. A method for a user equipment (UE) for sidelink (SL) communication, comprising: selecting a first SL synchronization signal block (S-SSB) frequency hopping pattern; transmitting a first plurality of S-SSBs to a first peer UE according to the first S-SSB frequency hopping pattern.

2. 2. The method of claim 1, wherein a synchronization signal identifier (SSID) used by the first plurality of S-SSBs corresponds to the first frequency hopping pattern.

3. selecting a second S-SSB frequency hopping pattern; transmitting a second plurality of S-SSBs to a second peer UE according to the second frequency hopping pattern; The method of claim 1 further comprising:

4. a first synchronization signal identifier (SSID) used by the first plurality of S-SSBs corresponds to the first frequency hopping pattern; 4. The method of claim 3, wherein a second SSID used by the second plurality of S-SSBs corresponds to the second frequency hopping pattern.

5. A method for a user equipment (UE) for sidelink (SL) communication, the method comprising transmitting a plurality of SL synchronization signal blocks (S-SSBs) in a frequency domain larger than eleven physical resource blocks (PRBs).

6. 6. The method of claim 5, wherein each of the plurality of S-SSBs includes more than 11 PRBs.

7. The method of claim 5 , wherein the plurality of S-SSBs comprises a repeated S-SSB in the frequency domain.

8. A method for a first user equipment (UE) for sidelink (SL) communication, comprising: receiving, from a second UE, one or more indices corresponding to a configured set of SL synchronization signal blocks (S-SSBs); receiving one or more S-SSBs from the second UE, each of the one or more S-SSBs indicating a corresponding index of the one or more indexes; Including, A method of a first user equipment (UE), wherein each of the one or more S-SSBs is transmitted by the second UE according to beamforming corresponding to the corresponding index.

9. The method of claim 8, wherein each of the one or more S-SSBs implicitly indicates the corresponding index based on a transmission timing.

10. 9. The method of claim 8, wherein each of the one or more S-SSBs indicates the corresponding index in a Physical Sidelink Broadcast Channel (PSBCH) payload.

11. each of the one or more S-SSBs indicating a first portion of the corresponding index in a Physical Sidelink Broadcast Channel (PSBCH) payload; 10. The method of claim 8, wherein each of the one or more S-SSBs indicates the second portion of the corresponding index using one of a Physical Sidelink Broadcast Channel (PSBCH) scrambling, a Cyclic Redundancy Check (CRC) scrambling, and a location of a PSBCH demodulation reference signal (DMRS) within the one or more S-SSBs.

12. 9. The method of claim 8, wherein each of the one or more S-SSBs indicates the corresponding index using a sequence found in the one or more S-SSBs.

13. 9. The method of claim 8, wherein each of the one or more S-SSBs transmits each of its symbols according to one or more of the same Doppler spread, the same Doppler shift, the same average delay, the same delay spread, and the same spatial receive (Rx) parameters.

14. The method of claim 8, wherein each of the one or more S-SSBs is transmitted at the same power.

15. 9. The method of claim 8, wherein a current S-SSB of the one or more S-SSBs indicating the same corresponding index as a previous S-SSB of the one or more S-SSBs is transmitted according to one or more of the following: a same Doppler spread used to transmit the previous S-SSB, a same Doppler shift used to transmit the previous S-SSB, a same average delay used to transmit the previous S-SSB, a same delay spread used to transmit the previous S-SSB, a same spatial receive (Rx) parameter used to transmit the previous S-SSB, and a same power used to transmit the previous S-SSB.

16. 9. The method of claim 8, wherein at least one of the one or more S-SSBs is configured to be used for one or more of a first reference signal for quasi-co-location, a second reference signal for path loss estimation, a third reference signal for radio link monitoring (RLM), a fourth reference signal for beam failure detection (BFD), and a fifth reference signal for candidate beam detection (CBD).

17. A user equipment (UE) method for sidelink (SL) communication, comprising transmitting one or more SL synchronization signal blocks (S-SSBs) corresponding to a set of configured S-SSBs using one of a frequency domain masking procedure and a time domain masking procedure.

18. the one or more S-SSBs include a first S-SSB transmitted using the frequency domain masking procedure; the first S-SSB comprises a block of entries of a transmitted sequence of the S-SSB in the frequency domain; each block of transmitted sequence entries containing all entries for the transmitted sequence of the S-SSB; 20. The method of claim 17, wherein each block of entries is masked by a different element of the masking sequence.

19. the one or more S-SSBs include a first S-SSB transmitted using the frequency domain masking procedure; the first S-SSB comprises a block of entries of a transmitted sequence of the S-SSB in the frequency domain; 18. The method of claim 17, wherein each block of entries comprises a repetition of one entry of the transmitted sequence of the S-SSB, each repetition being masked by a different element of a masking sequence.

20. 18. The method of claim 17, wherein the one or more S-SSBs are transmitted using the time-domain masking procedure, the one or more S-SSBs including repetitions of an S-SSB corresponding to one of the configured set of S-SSBs in the time domain, each repetition being masked by a different element of a masking sequence.

21. The method of claim 20 , wherein each element of the masking sequence corresponds to a value having unit energy.

22. The method of claim 20 , wherein the elements of the masking sequences are identical.

23. The method of claim 20 , wherein the elements of the masking sequence are constructed to have good autocorrelation.

24. 21. The method of claim 20, wherein each of the repetitions of the S-SSB is sent according to one or more of the same Doppler spread, same Doppler shift, same average delay, same delay spread, same spatial receive (Rx) parameters, and same transmit power.

25. The method of any one of claims 1, 5, 8, or 17, wherein the SL communication is performed according to an S-SSB periodicity of less than 160 ms.

26. The method of claim 25, wherein the S-SSB periodicity is configured in an SL-SyncConfig information element.

27. 18. The method of claim 1, 5, 8, or 17, wherein the SL communication uses a subcarrier spacing that is greater than or equal to 15 kilohertz (kHz) and less than or equal to 60 kHz, and the SL communication includes transmitting 64 or more configured S-SSBs within one period of S-SSB periodicity.

28. 18. The method of claim 1, claim 5, claim 8, or claim 17, wherein the SL communication uses a subcarrier spacing of 15 kilohertz (kHz) or more and 120 kHz or less, and the SL communication includes transmitting 128 or more configured S-SSBs within one period of S-SSB periodicity.

29. performing a clear channel assessment (CCA) for a carrier to be used by the UE for S-SSB transmission; and performing the S-SSB transmission after completion of the CCA.

30. 30. The method of claim 29, further comprising including, in the S-SSB transmission, an indication of an amount of transmission delay imposed on the S-SSB transmission by the CCA relative to a configured transmit timing for the S-SSB transmission.

31. The method of claim 1 , further comprising: identifying, for the peer UE, one or more configured S-SSBs of a set of configured S-SSBs.

32. 32. The method of claim 31 , wherein the one or more configured S-SSBs are identified to the peer UE using a bitmap, each bit of the bitmap corresponding to one of the set of configured S-SSBs.

33. the one or more configured S-SSBs are identified to the peer UE using a first bitmap and a second bitmap; the first bitmap identifies a segment of the set of configured S-SSBs that includes one or more of the configured S-SSBs; 32. The method of claim 31, wherein the second bitmap identifies the one or more of the configured S-SSBs in each segment.

34. 6. The method of claim 5, further comprising identifying, to the peer UE, one or more configured S-SSBs of a set of configured S-SSBs.

35. 35. The method of claim 34, wherein the one or more configured S-SSBs are identified to the peer UE using a bitmap, each bit of the bitmap corresponding to one of the set of configured S-SSBs.

36. the one or more configured S-SSBs are identified to the peer UE using a first bitmap and a second bitmap; the first bitmap identifies a segment of the set of configured S-SSBs that includes one or more of the configured S-SSBs; 35. The method of claim 34, wherein the second bitmap identifies the one or more of the configured S-SSBs in each segment.

37. A method according to any one of claims 8 and 17, comprising identifying to a peer UE one or more configured S-SSBs of the set of configured S-SSBs.

38. 38. The method of claim 37, wherein the one or more configured S-SSBs are identified to the peer UE using a bitmap, each bit of the bitmap corresponding to one of the set of configured S-SSBs.

39. the one or more configured S-SSBs are identified to the peer UE using a first bitmap and a second bitmap; the first bitmap identifies a segment of the set of configured S-SSBs that includes one or more of the configured S-SSBs; 38. The method of claim 37, wherein the second bitmap identifies the one or more of the configured S-SSBs in each segment.

40. Apparatus comprising means for carrying out the method according to any one of claims 1 to 39.

41. A computer readable medium comprising instructions which, when executed by one or more processors of an electronic device, cause the electronic device to perform the method of any one of claims 1 to 39.

42. An apparatus comprising logic, modules or circuitry for carrying out a method according to any one of claims 1 to 39.

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