WO2024109168A1

WO2024109168A1 - Methods and apparatuses for transmissions over sidelink in unlicensed spectra

Info

Publication number: WO2024109168A1
Application number: PCT/CN2023/112002
Authority: WO
Inventors: Xin Guo; Haipeng Lei; Zhennian SUN; Xiaodong Yu
Original assignee: Lenovo Beijing Ltd
Current assignee: Lenovo Beijing Ltd
Priority date: 2023-08-09
Filing date: 2023-08-09
Publication date: 2024-05-30
Anticipated expiration: 2026-02-09
Also published as: WO2024109168A9

Abstract

Various aspects of the present disclosure relate to methods and apparatuses for transmissions over sidelink (SL) in unlicensed spectra. According to an embodiment of the present disclosure, a user equipment (UE) can include: at least one memory; and at least one processor coupled with the at least one memory and configured to cause the UE to: select an SL synchronization signal block (S-SSB) occasion in a slot, wherein a first slot structure for the S-SSB occasion is based on a second slot structure for an additional transmission over SL in the slot, and wherein the S-SSB occasion is on a first channel and the additional transmission over SL is on a second channel; and transmit S-SSB on the selected S-SSB occasion in the case that the first channel is available for transmitting the S-SSB.

Description

METHODS AND APPARATUSES FOR TRANSMISSIONS OVER SIDELINK IN UNLICENSED SPECTRA

TECHNICAL FIELD

The present disclosure relates to wireless communications, and more specifically to methods and apparatuses for transmissions over sidelink (SL) in unlicensed spectra.

BACKGROUND

A wireless communications system may include one or multiple network communication devices, such as base stations (BSs) , which may support wireless communications for one or multiple user communication devices, which may be otherwise known as user equipment (UE) , or other suitable terminology. The wireless communications system may support wireless communications with one or multiple user communication devices by utilizing resources of the wireless communication system (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers, or the like) . Additionally, the wireless communications system may support wireless communications across various radio access technologies including third generation (3G) radio access technology, fourth generation (4G) radio access technology, fifth generation (5G) radio access technology, among other suitable radio access technologies beyond 5G (e.g., sixth generation (6G) ) .

SUMMARY

An article "a" before an element is unrestricted and understood to refer to "at least one" of those elements or "one or more" of those elements. The terms "a, " "at least one, " "one or more, " and "at least one of one or more" may be interchangeable. As used herein, including in the claims, "or" as used in a list of items (e.g., a list of items prefaced by a phrase such as "at least one of" or "one or more of" or "one or both of" ) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) . Also, as used herein, the phrases "based on" and "according to" shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as "based on condition A" may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase "based on" shall be construed in the same manner as the phrase "based at least in part on. " Further, as used herein, including in the claims, a "set" may include one or more elements.

Some implementations of the methods and apparatuses described herein may include a UE for wireless communication. The UE may include: at least one memory; and at least one processor coupled with the at least one memory and configured to cause the UE to: select an SL synchronization signal block (S-SSB) occasion in a slot, wherein a first slot structure for the S-SSB occasion is based on a second slot structure for an additional transmission over SL in the slot, and wherein the S-SSB occasion is on a first channel and the additional transmission over SL is on a second channel; and transmit S-SSB on the selected S-SSB occasion in the case that the first channel is available for transmitting the S-SSB.

In some implementations of the UE described herein, the second slot structure includes only one candidate starting symbol for an SL transmission in the slot, and the first slot structure includes an automatic gain control (AGC) symbol which is aligned with the candidate starting symbol.

In some implementations of the UE described herein, the AGC symbol is a duplication of a next physical sidelink broadcast channel (PSBCH) symbol within the S-SSB occasion, in the case that the candidate starting symbol is one of a first symbol, a second symbol, a third symbol, a fourth symbol, a fifth symbol, a sixth symbol, or a seventh symbol in the slot.

In some implementations of the UE described herein, the second slot structure includes a first candidate starting symbol and a second candidate starting symbol with up to two AGC symbols for an SL transmission in the slot, and the first slot structure includes a first AGC symbol which is aligned with the first candidate starting symbol and a second AGC symbol which is aligned with the second candidate starting symbol.

In some implementations of the UE described herein, the first candidate starting symbol is the first symbol in the slot, and the second candidate starting symbol is one of a sixth symbol, a seventh symbol, or an eighth symbol in the slot.

In some implementations of the UE described herein, the second slot structure includes a first candidate starting symbol and a second candidate starting symbol with only one AGC symbol for an SL transmission in the slot, and the first slot structure includes an AGC symbol which is aligned with the first candidate starting symbol.

In some implementations of the UE described herein, the second slot structure includes a first AGC symbol for an SL transmission in the slot and a second AGC symbol for a physical sidelink feedback channel (PSFCH) transmission in the slot, and the first slot structure includes a third AGC symbol which is aligned with the first AGC symbol and a fourth AGC symbol which is aligned with the second AGC symbol.

In some implementations of the UE described herein, the second slot structure further includes a first gap symbol between the SL transmission and the PSFCH transmission in the slot, and the first slot structure further includes a second gap symbol or a fifth AGC symbol which is aligned with the first gap symbol.

In some implementations of the UE described herein, the first slot structure is configured or pre-configured to the UE, is defined, or is pre-defined.

Some implementations of the methods and apparatuses described herein may include a processor for wireless communication. The processor may include: at least one controller coupled with at least one memory and configured to cause the processor to: select an S-SSB occasion in a slot, wherein a first slot structure for the S-SSB occasion is based on a second slot structure for an additional transmission over SL in the slot, and wherein the S-SSB occasion is on a first channel and the additional transmission over SL is on a second channel; and transmit S-SSB on the selected S-SSB occasion in the case that the first channel is available for transmitting the S-SSB.

Some implementations of the methods and apparatuses described herein may include a UE for wireless communication. The UE may include: at least one memory; and at least one processor coupled with the at least one memory and configured to cause the UE to: monitor one or more AGC symbols within an S-SSB occasion in a slot, wherein a first slot structure for the S-SSB occasion is based on a second slot structure for an additional transmission over SL in the slot, and wherein the S-SSB occasion is on a first channel and the additional transmission over SL is on a second channel; and tune AGC based on the monitored one or more AGC symbols.

In some implementations of the UE described herein, the second slot structure includes only one candidate starting symbol for an SL transmission in the slot, and the first slot structure includes an AGC symbol which is aligned with the candidate starting symbol.

In some implementations of the UE described herein, the AGC symbol is a duplication of a next PSBCH symbol within the S-SSB occasion, in the case that the candidate starting symbol is one of a first symbol, a second symbol, a third symbol, a fourth symbol, a fifth symbol, a sixth symbol, or a seventh symbol in the slot.

In some implementations of the UE described herein, the second slot structure includes a first AGC symbol for an SL transmission in the slot and a second AGC symbol for a PSFCH transmission in the slot, and the first slot structure includes a third AGC symbol which is aligned with the first AGC symbol and a fourth AGC symbol which is aligned with the second AGC symbol.

In some implementations of the UE described herein, the monitored one or more AGC symbols include at least the AGC symbol in the first slot structure.

In some implementations of the UE described herein, the monitored one or more AGC symbols include at least the first AGC symbol and the second AGC symbol.

In some implementations of the UE described herein, the monitored one or more AGC symbols include at least the third AGC symbol and the fourth AGC symbol.

Some implementations of the methods and apparatuses described herein may include a processor for wireless communication. The processor may include: at least one controller coupled with at least one memory and configured to cause the processor to: monitor one or more AGC symbols within an S-SSB occasion in a slot, wherein a first slot structure for the S-SSB occasion is based on a second slot structure for an additional transmission over SL in the slot, and wherein the S-SSB occasion is on a first channel and the additional transmission over SL is on a second channel; and tune AGC based on the monitored one or more AGC symbols.

Some implementations of the methods and apparatuses described herein may include a UE for wireless communication. The UE may include: at least one memory; and at least one processor coupled with the at least one memory and configured to cause the UE to: monitor an S-SSB occasion in a slot, wherein a first slot structure for the S-SSB occasion is based on a second slot structure for an SL transmission in the slot, wherein the second slot structure includes a first candidate starting symbol and a second candidate starting symbol for the SL transmission, and wherein the S-SSB occasion is on a first channel and the SL transmission is on a second channel; and perform the SL transmission from the second candidate starting symbol in the slot in response to at least not detecting S-SSB transmission within the slot and the second channel being available for performing the SL transmission.

Some implementations of the methods and apparatuses described herein may include a processor for wireless communication. The processor may include: at least one controller coupled with at least one memory and configured to cause the processor to: monitor an S-SSB occasion in a slot, wherein a first slot structure for the S-SSB occasion is based on a second slot structure for an SL transmission in the slot, wherein the second slot structure includes a first candidate starting symbol and a second candidate starting symbol for the SL transmission, and wherein the S-SSB occasion is on a first channel and the SL transmission is on a second channel; and perform the SL transmission from the second candidate starting symbol in the slot in response to at least not detecting S-SSB transmission within the slot and the second channel being available for performing the SL transmission.

Some implementations of the methods and apparatuses described herein may include a BS for wireless communication. The BS may include: at least one memory; and at least one processor coupled with the at least one memory and configured to cause the BS to: transmit, to a UE, a first slot structure for an S-SSB occasion in a slot, wherein the first slot structure is based on a second slot structure for an additional transmission over SL in the slot, and wherein the S-SSB occasion is on a first channel and the additional transmission over SL is on a second channel.

In some implementations of the BS described herein, the at least one processor is configured to cause the BS to transmit the first slot structure via at least one of: a master information block (MIB) message, a system information block (SIB) message, a radio resource control (RRC) signaling, a medium access control (MAC) control element (CE) , or downlink control information (DCI) .

Some implementations of the methods and apparatuses described herein may include a method performed by a UE. The method may include: selecting an S-SSB occasion in a slot, wherein a first slot structure for the S-SSB occasion is based on a second slot structure for an additional transmission over SL in the slot, and wherein the S-SSB occasion is on a first channel and the additional transmission over SL is on a second channel; and transmitting SSB on the selected S-SSB occasion in the case that the first channel is available for transmitting the S-SSB.

Some implementations of the methods and apparatuses described herein may include a method performed by a UE. The method may include: monitoring one or more AGC symbols within an S-SSB occasion in a slot, wherein a first slot structure for the S-SSB occasion is based on a second slot structure for an additional transmission over SL in the slot, and wherein the S- SSB occasion is on a first channel and the additional transmission over SL is on a second channel; and tuning AGC based on the monitored one or more AGC symbols.

Some implementations of the methods and apparatuses described herein may include a method performed by a UE. The method may include: monitoring an S-SSB occasion in a slot, wherein a first slot structure for the S-SSB occasion is based on a second slot structure for an SL transmission in the slot, wherein the second slot structure includes a first candidate starting symbol and a second candidate starting symbol for the SL transmission, and wherein the S-SSB occasion is on a first channel and the SL transmission is on a second channel; and performing the SL transmission from the second candidate starting symbol in the slot in response to at least not detecting S-SSB transmission within the slot and the second channel being available for performing the SL transmission.

Some implementations of the methods and apparatuses described herein may include a method performed by a BS. The method may include: transmitting, to a UE, a first slot structure for an S-SSB occasion in a slot, wherein the first slot structure is based on a second slot structure for an additional transmission over SL in the slot, and wherein the S-SSB occasion is on a first channel and the additional transmission over SL is on a second channel.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to describe the manner in which advantages and features of the application can be obtained, a description of the application is rendered by reference to specific embodiments thereof, which are illustrated in the appended drawings. These drawings depict only example embodiments of the application and are not therefore to be considered limiting of its scope.

Figure 1 illustrates an example of a wireless communications system in accordance with aspects of the present disclosure.

Figure 2A illustrates an exemplary S-SSB slot in accordance with aspects of the present disclosure.

Figure 2B illustrates an exemplary distribution of S-SSB occasions in the time domain in accordance with aspects of the present disclosure.

Figure 2C illustrates another exemplary distribution of S-SSB occasions in the time domain in accordance with aspects of the present disclosure.

Figures 3A, 3B, 4, 5A and 5B illustrate exemplary slot structures for S-SSB occasions and SL transmissions in accordance with aspects of the present disclosure.

Figures 6A and 6B illustrate exemplary slot structures for S-SSB occasions, SL transmissions, and PSFCH transmissions in accordance with aspects of the present disclosure.

Figure 7 illustrates a flowchart of an exemplary method performed by a UE in accordance with aspects of the present disclosure.

Figure 8 illustrates a flowchart of another exemplary method performed by a UE in accordance with aspects of the present disclosure.

Figure 9 illustrates a flowchart of yet another exemplary method performed by a UE in accordance with aspects of the present disclosure.

Figure 10 illustrates an example of a UE in accordance with aspects of the present disclosure.

Figure 11 illustrates an example of a processor in accordance with aspects of the present disclosure.

Figure 12 illustrates an example of a BS in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

The detailed description of the appended drawings is intended as a description of preferred embodiments of the present application and is not intended to represent the only form in which the present application may be practiced. It should be understood that the same or equivalent functions may be accomplished by different embodiments that are intended to be encompassed within the spirit and scope of the present application.

While operations are depicted in the drawings in a particular order, persons skilled in the art will readily recognize that such operations need not be performed in the particular order as shown or in a sequential order, or that all illustrated operations need be performed, to achieve desirable results; sometimes one or more operations can be skipped. Further, the drawings can schematically depict one or more example processes in the form of a flow diagram. However, other operations that are not depicted can be incorporated in the example processes that are schematically illustrated. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the illustrated operations. In certain circumstances, multitasking and parallel processing can be advantageous.

Reference will now be made in detail to some embodiments of the present application, examples of which are illustrated in the accompanying drawings. To facilitate understanding, embodiments are provided under specific network architecture and new service scenarios, such as 3rd generation partnership project (3GPP) long-term evolution (LTE) and LTE advanced, 3GPP 5G new radio (NR) , 5G-Advanced, 6G, and so on. It is contemplated that along with developments of network architectures and new service scenarios, all embodiments in the present application are also applicable to similar technical problems; and moreover, the terminologies recited in the present application may change, which should not affect the principle of the present application.

Aspects of the present disclosure are described in the context of a wireless communications system.

Figure 1 illustrates an example of a wireless communications system 100 in accordance with aspects of the present disclosure. The wireless communications system 100 may include one or more network equipments (NEs) (e.g., BSs) 102, one or more UEs 104, and a core network (CN) 106. The wireless communications system 100 may support various radio access technologies. In some implementations, the wireless communications system 100 may be a 4G network, such as an LTE network or an LTE-Advanced (LTE-A) network. In some other implementations, the wireless communications system 100 may be a NR network, such as a 5G network, a 5G-Advanced (5G-A) network, or a 5G ultrawideband (5G-UWB) network. In other implementations, the wireless communications system 100 may be a combination of a 4G network and a 5G network, or other suitable radio access technology including Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20. The wireless communications system 100 may support radio access technologies beyond 5G, for example, 6G. Additionally, the wireless communications system 100 may support technologies, such as time division multiple access (TDMA) , frequency division multiple access (FDMA) , or code division multiple access (CDMA) , etc.

The one or more NEs 102 may be dispersed throughout a geographic region to form the wireless communications system 100. One or more of the NEs 102 described herein may be or include or may be referred to as a network node, a base station, a network element, a network function, a network entity, a radio access network (RAN) , a NodeB, an eNodeB (eNB) , a next-generation NodeB (gNB) , or other suitable terminology. An NE 102 and a UE 104 may communicate via a communication link, which may be a wireless or wired connection. For example, an NE 102 and a UE 104 may perform wireless communication (e.g., receive signaling, transmit signaling) over a Uu interface.

An NE 102 may provide a geographic coverage area for which the NE 102 may support services for one or more UEs 104 within the geographic coverage area. For example, an NE 102 and a UE 104 may support wireless communication of signals related to services (e.g., voice, video, packet data, messaging, broadcast, etc. ) according to one or multiple radio access technologies. In some implementations, an NE 102 may be moveable, for example, a satellite associated with a non-terrestrial network (NTN) . In some implementations, different geographic coverage areas associated with the same or different radio access technologies may overlap, but the different geographic coverage areas may be associated with different NEs 102.

The one or more UEs 104 may be dispersed throughout a geographic region of the wireless communications system 100. A UE 104 may include or may be referred to as a remote unit, a mobile device, a wireless device, a remote device, a subscriber device, a transmitter device, a receiver device, or some other suitable terminology. In some implementations, the UE 104 may be referred to as a unit, a station, a terminal, or a client, among other examples. Additionally, or alternatively, the UE 104 may be referred to as an Internet-of-Things (IoT) device, an Internet-of-Everything (IoE) device, or machine-type communication (MTC) device, among other examples.

A UE 104 may be able to support wireless communication directly with other UEs 104 over a communication link. For example, a UE 104 may support wireless communication directly with another UE 104 over a device-to-device (D2D) communication link. In some implementations, such as vehicle-to-vehicle (V2V) deployments, vehicle-to-everything (V2X) deployments, or cellular-V2X deployments, the communication link may be referred to as a sidelink. For example, a UE 104 may support wireless communication directly with another UE 104 over a PC5 interface.

An NE 102 may support communications with the CN 106, or with another NE 102, or both. For example, an NE 102 may interface with other NE 102 or the CN 106 through one or more backhaul links (e.g., S1, N2, N2, or network interface) . In some implementations, the NEs 102 may communicate with each other directly. In some other implementations, the NEs 102 may communicate with each other indirectly (e.g., via the CN 106. In some implementations, one or more NEs 102 may include subcomponents, such as an access network entity, which may be an example of an access node controller (ANC) . An ANC may communicate with the one or more UEs 104 through one or more other access network transmission entities, which may be referred to as radio heads, smart radio heads, or transmission-reception points (TRPs) .

The CN 106 may support user authentication, access authorization, tracking, connectivity, and other access, routing, or mobility functions. The CN 106 may be an evolved packet core (EPC) , or a 5G core (5GC) , which may include a control plane entity that manages access and mobility (e.g., a mobility management entity (MME) , an access and mobility management function (AMF) ) and a user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW) , a Packet Data Network (PDN) gateway (P-GW) , or a user plane function (UPF) ) . In some implementations, the control plane entity may manage non-access stratum (NAS) functions, such as mobility, authentication, and bearer management (e.g., data bearers, signal bearers, etc. ) for the one or more UEs 104 served by the one or more NEs 102 associated with the CN 106.

The CN 106 may communicate with a packet data network over one or more backhaul links (e.g., via an S1, N2, N2, or another network interface) . The packet data network may include an application server. In some implementations, one or more UEs 104 may communicate with the application server. A UE 104 may establish a session (e.g., a protocol data unit (PDU) session, or the like) with the CN 106 via an NE 102. The CN 106 may route traffic (e.g., control information, data, and the like) between the UE 104 and the application server using the established session (e.g., the established PDU session) . The PDU session may be an example of a logical connection between the UE 104 and the CN 106 (e.g., one or more network functions of the CN 106) .

In the wireless communications system 100, the NEs 102 and the UEs 104 may use resources of the wireless communications system 100 (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers) ) to perform various operations (e.g., wireless communications) . In some implementations, the NEs 102 and the UEs 104 may support different resource structures. For example, the NEs 102 and the UEs 104 may support different frame structures. In some implementations, such as in 4G, the NEs 102 and the UEs 104 may support a single frame structure. In some other implementations, such as in 5G and among other suitable radio access technologies, the NEs 102 and the UEs 104 may support various frame structures (e.g., multiple frame structures) . The NEs 102 and the UEs 104 may support various frame structures based on one or more numerologies.

One or more numerologies may be supported in the wireless communications system 100, and a numerology may include a subcarrier spacing and a cyclic prefix. A first numerology (e.g., μ=0) may be associated with a first subcarrier spacing (e.g., 15 kHz) and a normal cyclic prefix. In some implementations, the first numerology (e.g., μ=0) associated with the first subcarrier spacing (e.g., 15 kHz) may utilize one slot per subframe. A second numerology (e.g., μ=1) may be associated with a second subcarrier spacing (e.g., 30 kHz) and a normal cyclic prefix. A third numerology (e.g., μ=2) may be associated with a third subcarrier spacing (e.g., 60 kHz) and a normal cyclic prefix or an extended cyclic prefix. A fourth numerology (e.g., μ=3) may be associated with a fourth subcarrier spacing (e.g., 120 kHz) and a normal cyclic prefix. A fifth numerology (e.g., μ=4) may be associated with a fifth subcarrier spacing (e.g., 240 kHz) and a normal cyclic prefix.

A time interval of a resource (e.g., a communication resource) may be organized according to frames (also referred to as radio frames) . Each frame may have a duration, for example, a 10 millisecond (ms) duration. In some implementations, each frame may include multiple subframes. For example, each frame may include 10 subframes, and each subframe may have a duration, for example, a 1 ms duration. In some implementations, each frame may have the same duration. In some implementations, each subframe of a frame may have the same duration.

Additionally or alternatively, a time interval of a resource (e.g., a communication resource) may be organized according to slots. For example, a subframe may include a number (e.g., quantity) of slots. The number of slots in each subframe may also depend on the one or more numerologies supported in the wireless communications system 100. For instance, the first, second, third, fourth, and fifth numerologies (e.g., μ=0, μ=1, μ=2, μ=3, μ=4) associated with respective subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 240 kHz may utilize a single slot per subframe, two slots per subframe, four slots per subframe, eight slots per subframe, and 16 slots per subframe, respectively. Each slot may include a number (e.g., quantity) of symbols (e.g., orthogonal frequency division multiplexing (OFDM) symbols) . In some implementations, the number (e.g., quantity) of slots for a subframe may depend on a numerology. For a normal cyclic prefix, a slot may include 14 symbols. For an extended cyclic prefix (e.g., applicable for 60 kHz subcarrier spacing) , a slot may include 12 symbols. The relationship between the number of symbols per slot, the number of slots per subframe, and the number of slots per frame for a normal cyclic prefix and an extended cyclic prefix may depend on a numerology. It should be understood that reference to a first numerology (e.g., μ=0) associated with a first subcarrier spacing (e.g., 15 kHz) may be used interchangeably between subframes and slots.

In the wireless communications system 100, an electromagnetic (EM) spectrum may be split, based on frequency or wavelength, into various classes, frequency bands, frequency channels, etc. By way of example, the wireless communications system 100 may support one or multiple operating frequency bands, such as frequency range designations FR1 (410 MHz –7.125 GHz) , FR2 (24.25 GHz –52.6 GHz) , FR3 (7.125 GHz –24.25 GHz) , FR4 (52.6 GHz –114.25 GHz) , FR4a or FR4-1 (52.6 GHz –71 GHz) , and FR5 (114.25 GHz –300 GHz) . In some implementations, the NEs 102 and the UEs 104 may perform wireless communications over one or more of the operating frequency bands. In some implementations, FR1 may be used by the NEs 102 and the UEs 104, among other equipment or devices for cellular communications traffic (e.g., control information, data) . In some implementations, FR2 may be used by the NEs 102 and the UEs 104, among other equipment or devices for short-range, high data rate capabilities.

FR1 may be associated with one or multiple numerologies (e.g., at least three numerologies) . For example, FR1 may be associated with a first numerology (e.g., μ=0) , which includes 15 kHz subcarrier spacing; a second numerology (e.g., μ=1) , which includes 30 kHz subcarrier spacing; and a third numerology (e.g., μ=2) , which includes 60 kHz subcarrier spacing. FR2 may be associated with one or multiple numerologies (e.g., at least 2 numerologies) . For example, FR2 may be associated with a third numerology (e.g., μ=2) , which includes 60 kHz subcarrier spacing; and a fourth numerology (e.g., μ=3) , which includes 120 kHz subcarrier spacing.

In NR, accommodating multiple uncoordinated UEs in an unlicensed spectrum requires channel access procedures defined for NR. Following a successful channel access procedure performed by a communicating node, the channel can be used by the communicating node during a period until the end of the period. Such a period may be referred to as a COT. During a COT, one or more transmissions may be exchanged between the communicating nodes, wherein a transmission may be a downlink (DL) transmission or an uplink (UL) transmission.

Dynamic channel access procedures are usually used by a BS or a UE to access a channel in an unlicensed spectrum. Dynamic channel access procedures may be based on listen-before-talk (LBT) , where a transmitter listens to potential transmission activity on a channel prior to transmitting and applies a random back-off time in some cases. Two main types of dynamic channel access procedures may be defined in NR. One is Type-1 dynamic channel access procedure, which is also referred to as LBT type 1 or LBT cat4. The other is Type-2 dynamic channel access procedure, which is also referred to as LBT type 2.

Type-1 dynamic channel access procedure may be used to initiate data transmission at the beginning of a COT. The initiator for the Type-1 dynamic channel access procedure may be either a BS or a UE. The Type-1 dynamic channel access procedure may be summarized as follows.

First, the initiator listens and waits until a channel (e.g., a frequency channel) is available during at least one period referred to as a defer duration. The defer duration may consist of 16 μs and a number (e.g., "m_p" in the following Table 1 or Table 2, which will be illustrated below) of 9 μs slots. As shown in Table 1 and Table 2, a value of "m_p" depends on a value of CAPC (represented as "p" ) . Accordingly, the defer duration depends on the value of CAPC as shown in the following Table 1 or Table 2. A channel is declared to be available if the received energy during at least 4 μs of each 9 μs slot is below a threshold.

Once the channel has been declared available during the defer duration, the transmitter starts a random back-off procedure during which it will wait a random period of time.

The UE starts the random back-off procedure by initializing a back-off timer with a random number within a contention window (CW) . The random number is drawn from a uniform distribution [0, CW] and represents that the channel must be available for a timer duration (e.g., denoted by the random number multiplying 9 μs) before transmission can take place. The value of "CW" may be selected from "allowed CW_p sizes" (the minimum value is represented as CW_min, p , and the maximum value is represented as CW_max, p ) in the following Table 1 or Table 2, which depends on a value of CAPC.

The back-off timer is decreased by one for each sensing slot duration (e.g., 9 μs) the channel is sensed to be idle; whenever the channel is sensed to be busy, the back-off timer is put on hold until the channel has been idle for a defer duration.

Once the back-off timer has expired (e.g., the back-off timer is decreased to be 0) , the random back-off procedure is completed, and the transmitter has acquired the channel and can use it for transmission up to a maximum channel occupancy time (MCOT) (e.g., T_mcot, p in the following Table 1 or T_ulmcot, p in the following Table 2, which depends on a value of CAPC) .

The following Table 1 and Table 2 illustrate exemplary CAPC for DL and CAPC for UL, respectively, and corresponding values of m_p , CW_min, p , CW_max, p , T_mcot, p , T_ulmcot, p , and allowed CW_p sizes. Table 1 is the same as Table 4.1.1-1 in TS 37.213 and Table 2 is the same as Table 4.2.1-1 in TS 37.213. When a BS intends to initiate a channel occupancy for DL transmission, it may determine a CAPC value before performing a Type-1 channel access procedure, and then determine the corresponding values (e.g., m_p , CW_min, p , CW_max, p , T_mcot, p , and allowed CW_p sizes) used in the Type-1 channel access procedure according to Table 1. When a UE intends to initiate a channel occupancy for UL transmission, it may determine a CAPC value before performing a Type-1 channel access procedure, and then determine the corresponding values (e.g., m_p, CW_min, p, CW_max, p, T_ulmcot, p, and allowed CW_psizes) used in the Type-1 channel access procedure according to Table 2.

Table 1: Channel Access Priority Class for DL

Table 2: Channel Access Priority Class for UL

The size of the contention window may be adjusted based on HARQ reports received from the transmitter during a reference interval, which covers the beginning of the COT. For each received HARQ report, the contention window is (approximately) doubled up to the limit CW_max, p if a negative HARQ report (e.g., non-acknowledgement (NACK) ) is received. For a positive HARQ report (e.g., acknowledgement (ACK) ) , the contention window is reset to its minimum value, i.e., CW=CW_min, p.

Type-2 dynamic channel access procedure may be used for COT sharing and transmission of discovery bursts. Depending on a duration of a gap (also referred to as "COT sharing gap" ) in the COT, Type-2 dynamic channel access procedure may be further classified into the following three procedures, wherein which procedure to be used may be determined depending on the duration of the gap between two transmission bursts.

● Type 2A dynamic channel access procedure (also referred to as LBT cat2 or LBT type 2A) : which is used when the gap is 25 μs or more for transmission of the discovery bursts.

● Type 2B dynamic channel access procedure (also referred to as LBT type 2B) : which is used when the gap is 16 μs.

● Type 2C dynamic channel access procedure (also referred to as LBT type 2C) : which is used when the gap is 16 μs or less after the preceding transmission burst.

For Type 2C dynamic channel access procedure, no idle sensing is required between the transmission bursts. In such scenario, the duration of a transmission burst is limited to at most 584 μs. Such a short transmission burst may carry small amount of user data, uplink control information (UCI) such as HARQ status reports and channel state information (CSI) reports.

Type 2A dynamic channel access procedure and Type 2B dynamic channel access procedure may be similar to Type-1 dynamic channel access procedure but without the random back-off. That is, in Type 2A dynamic channel access procedure and Type 2B dynamic channel access procedure, if a channel is detected to be idle in the gap, it is declared to be available; if it is detected to be busy, the COT sharing has failed and the transmission cannot occur using COT sharing in this COT. If the COT sharing gap is 16 μs, Type 2B dynamic channel access procedure may be used and the channel must be detected to be idle in the 16 μs gap prior to the next transmission burst. If the COT sharing gap is 25 μs or longer, Type 2A dynamic channel access procedure may be used and the channel must be detected to be idle during at least 25 μs immediately preceding the next transmission burst.

The above embodiments provide several dynamic channel access procedures in an unlicensed spectrum for NR. These dynamic channel access procedures may also apply for sidelink transmissions in an unlicensed spectrum.

Sidelink synchronization information is carried in an S-SSB that consists of PSBCH, sidelink primary synchronization signal (S-PSS) and sidelink secondary synchronization signal (S-SSS) . Figure 2A illustrates an exemplary S-SSB slot according to some embodiments of the present disclosure. In the example of Figure 2A, a normal cyclic prefix (CP) is used.

Referring to Figure 2A, an S-SSB occupies one slot in the time domain and occupies 11 resource blocks (RBs) in the frequency domain. Each RB spans 12 subcarriers, thus the S-SSB bandwidth is 132 (11 × 12) subcarriers. In the example of Figure 2A, the S-SSB slot may include 14 OFDM symbols in total, e.g., symbol #0 to symbol #13. The S-PSS is transmitted repeatedly on the second and third symbols in the S-SSB slot, e.g., symbol #1 and symbol #2. The S-SSS is transmitted repeatedly on the fourth and fifth symbols in the S-SSB slot, e.g., symbol #3 and symbol #4. The S-PSS and the S-SSS occupy 127 subcarriers in the frequency domain, which are from the third subcarrier relative to the start of the S-SSB bandwidth up to the 129th subcarrier.

The S-PSS and the S-SSS are jointly referred to as the sidelink synchronization signal (SLSS) . The SLSS is used for time and frequency synchronization. By detecting the SLSS sent by a synchronization reference UE (also referred to as a SyncRef UE) , a UE is able to synchronize to the SyncRef UE and estimate the beginning of the frame and carrier frequency offsets.

The S-PSS may be generated from the maximum length sequences (m-sequences) that use the same design (i.e., generator polynomials, initial values and cyclic shifts, etc. ) which is used for generating the m-sequences in the primary synchronization signal (PSS) in the 3GPP documents. In NR Uu, there are three candidate sequences for PSS. However, only two candidate sequences are used for S-PSS.

The S-SSS may be generated from the Gold sequences that use the same design (i.e., generator polynomials, initial values and cyclic shifts, etc. ) which is utilized for generating the Gold sequences for the secondary synchronization signal (SSS) in the 3GPP documents. This results in 336 candidate sequences for S-SSS like for the SSS in NR Uu.

For the transmission of SLSS within an S-SSB, a SyncRef UE may select an S-PSS and an S-SSS out of the candidate sequences based on an SLSS identifier (ID) . The SLSS ID represents an identifier of the SyncRef UE and conveys a priority of the SyncRef UE as in LTE vehicle-to-everything (V2X) . Each SLSS ID corresponds to a unique combination of an S-PSS and an S-SSS out of the 2 S-PSS candidate sequences and the 336 S-SSS candidate sequences.

The main purpose of the PSBCH is to provide system-wide information and synchronization information that is required by a UE for establishing a sidelink connection. In the example of Figure 2A, the PSBCH is transmitted on the first symbol (e.g., symbol #0) and the eight symbols (e.g., symbol #5 to symbol #12) after the S-SSS in the S-SSB slot. In the case that an extended CP is used, the PSBCH is transmitted on the first symbol and the six symbols after the S-SSS in the S-SSB slot. The PSBCH occupies 132 subcarriers in the frequency domain. The PSBCH in the first symbol of the S-SSB slot is used for AGC. The last symbol, e.g., symbol #13, in the S-SSB slot is used as a guard symbol (also referred to as a gap symbol) .

The structure of S-SSB slot in Figure 2A is only for illustrative purpose. It is contemplated that along with developments of network architectures and new service scenarios, the S-SSB may have other structures (for example, the S-SSB may include 4 OFDM symbols or 6 OFDM symbols in the time domain) , which should not affect the principle of the present application.

Figure 2B illustrates an exemplary distribution of S-SSB occasions in the time domain according to some embodiments of the present disclosure.

Figure 2B illustrates an S-SSB period as an example. Resource pool is also illustrated in the figure. A resource pool may define the overall time and frequency domain resources that can be used for SL transmission within a carrier. The SL transmission in the embodiments of the present application may refer to at least one of physical sidelink control channel (PSCCH) transmission or physical sidelink shared channel (PSSCH) transmission. In the time domain, the resource pool consists of a set of slots repeated over a resource pool period. Although the set of slots within the resource pool are logically organized in a consecutive way, actually the slots within the resource pool may be discretely distributed in the time domain.

As shown in Figure 2B, in the S-SSB period, N S-SSB occasions are included, which are labeled by S-SSB occasion #0, S-SSB occasion #1, S-SSB occasion #2, …, S-SSB occasion #N-1, respectively.

A length of the S-SSB period is marked as "S-SSB Period" in Figure 2B. There is a time offset between the starting of the S-SSB period and the first S-SSB occasion within the S-SSB period, which is marked as "T_Offset" in Figure 2B. There is a time interval between two adjacent S-SSB occasions (e.g., between the ending point of the former S-SSB occasion and the starting point of the latter S-SSB occasion) , which is marked as "T_Interval" in Figure 2B.

In 3GPP Release 16 (Rel-16) or Release 17 (Rel-17) , the S-SSB period may include 160ms, as specified in NR V2X. However, along with developments of network architectures and new service scenarios, the S-SSB period may have other values, which should not affect the principle of the disclosure. In the examples of Figure 2B, the distribution of S-SSB occasion (s) may be denoted by at least one of the following parameters: S-SSB period, T_Offset, T_Interval, or N as stated above.

Figure 2C illustrates an exemplary distribution of S-SSB occasions in the time domain, which are organized in a grouping manner, according to some embodiments of the present disclosure.

Figure 2C illustrates an S-SSB period as an example. A length of the S-SSB period is marked as "S-SSB Period" in Figure 2C. The S-SSB period includes N1 S-SSB groups, which are S-SSB group #0, S-SSB group #1, …, and S-SSB group #N1-1. Each S-SSB group includes N2 consecutive S-SSB occasions, which are S-SSB occasion #0, S-SSB occasion #1, …, and S-SSB occasion #N2-1.

There is a time offset between the starting of the S-SSB period and a starting of the first S-SSB group within the S-SSB period, which is marked as "T_OffsetGroup" in Figure 2C. There is a time interval between two adjacent S-SSB groups (e.g., between the ending point of the former S-SSB group and the starting point of the latter S-SSB group) , which is marked as "T_{IntervalGroup}" in Figure 2C. Accordingly, the distribution of S-SSB occasions in the example of Figure 2C may be defined by at least one of the following parameters: the parameter "S-SSB Period, " the parameter "T_OffsetGroup, " the parameter "T_{IntervalGroup}, " the parameter "N1, " or the parameter "N2. "

According to some embodiments of the present application, for unlicensed spectra, a frequency range (e.g., a bandwidth part (BWP) , a carrier, a resource pool, etc. ) may be divided into multiple channels upon which a channel access procedure is defined. Each channel may be referred to as an RB set. Operating on the carrier may require guard bands between RB sets. In some embodiments, the size of the guard bands may be chosen such that no filtering is needed to ensure that transmission on one RB set does not cause significant interference to a neighboring RB set not available for transmission.

For example, the concept of "RB set" is specified in Release 16 5G NR in unlicensed spectrum (NR-U) , which defines the exact available RBs without RBs in either inter-cell guard band or intra-cell guard band. The guard band and RB set are configured by RRC signaling in unit of common resource block (CRB) . In detail, when a UE is configured with intraCellGuardBand for a carrier, the UE is provided with N_RB-set-1 intra-cell guard bands on the carrier, each defined by a start CRB and an end CRB, i.e., andrespectively. The intra-cell guard bands separate N_RB-set RB sets, each defined by a start CRB and an end CRB, i.e., andrespectively. The UE determines and the remaining end and start CRBs as andWhen the UE is not configured with intraCellGuardBand, the UE determines intra-cell guard band and corresponding RB set according to the default intra-cell guard band pattern from TS38.101 corresponding to μ and carrier sizeThe specific definitions of the variables or parameters as mentioned above can be found in 3GPP standard documents.

As an example, a carrier wider than 20MHz may be divided into multiple 20MHz channels upon which a channel access procedure is defined. Each 20MHz channel may be referred to as one RB set.

The following Table 3 shows the number of RBs (e.g., N_RB) included in different bandwidths for different SCSs for FR1 (e.g., 450 MHz–7125 MHz) .

Table 3: Max transmission bandwidth configuration N_RB for FR1

Referring to Table 3, taking 20MHz bandwidth as an example, for 15kHz SCS, the 20MHz bandwidth includes 106 RBs (e.g., an RB set may include 106 RBs) ; for 30kHz SCS, the 20MHz bandwidth includes 51 RBs.

When a frequency range includes multiple channels (i.e., RB sets) , if the distribution of S-SSB occasions is configured per channel, there may be a case where an S-SSB occasion and an additional transmissions over SL from different channels are located within the same slot. Herein, the S-SSB transmission and the additional transmission over SL may be collectively referred to as transmissions over SL. The additional transmission over SL may include an SL transmission, or an SL transmission and a PSFCH transmission. An SL transmission may include at least one of a PSCCH transmission or a PSSCH transmission.

According to some embodiments of the present disclosure, two candidate starting symbols may be supported in a slot for an SL transmission over an unlicensed spectrum. In the present application, the two candidate starting symbols may be referred to as a first candidate starting symbol (or 1^st starting symbol) and a second candidate starting symbol (or 2^nd starting symbol) , respectively. In some examples, the location of the 1^st starting symbol may be (pre-) configured from symbols {#0, #1, #2, #3, #4, #5, #6} per BWP, and by default, the 1^st starting symbol is symbol #0. In some examples, the location of the 2^nd starting symbol may be (pre-) configured from symbols {#3, #4, #5, #6, #7} per BWP. The (pre-) configuration of the 2^nd starting symbol needs to meet the following requirements: within a slot, the 2^nd starting symbol is later than the 1^st starting symbol, and the number of symbols used for SL transmission from the 2^nd starting symbol is not smaller than 6. The flexible slot structure, where SL transmissions are not constrained to the slot boundaries, is beneficial as it can reduce the delay from a successful channel access procedure to an SL transmission.

In unlicensed spectra, an SL transmission can be started only after a successful channel access procedure by a UE. In the case that two candidate starting symbols are supported in a slot for an SL transmission, the starting symbol of the SL transmission may be the 1^st starting symbol or the 2^nd starting symbol. For example, when a channel is determined to be available before the 1^st starting symbol based on a successful channel access procedure, the UE may transmit the SL transmission from the 1^st starting symbol. When the UE fails to access a channel from the 1^st starting symbol, the UE may transmit the SL transmission from the 2^nd starting symbol after a successful channel access procedure before the 2^nd starting symbol.

In the case that an S-SSB occasion and additional transmissions over SL from different channels are located within the same slot, the SL transmission (i.e., PSSCH transmission and/or PSCCH transmission) or PSFCH transmission which does not start from the starting boundary (i.e., the first symbol) of the slot would cause an AGC issue to an S-SSB transmission (e.g., with the slot structure as shown in Figure 2A) starting from the starting boundary of the slot, resulting in an incorrect reception of the S-SSB.

For example, it is assumed that a first UE transmitting an SL transmission which starts from the second candidate starting symbol within a slot locates close to a second UE receiving an S-SSB transmission which starts from the starting boundary of the slot. The AGC of the second UE is trained based on the AGC symbol (i.e., the first symbol) in the slot. Then, the AGC setting of the second UE may be not appropriate from the second half (e.g., from the second candidate starting symbol) of the slot, due to the transmission from the first UE.

Embodiments of the present disclosure provide solutions for transmissions over SL in unlicensed spectra, which can resolve the AGC issue caused by multiple starting symbols for SL transmission or PSFCH transmission when an S-SSB occasion and at least one of SL transmission or PSFCH transmission from different channels are within the same slot. Specifically, embodiments of the present disclosure provide slot structures for S-SSB and UE behaviors for performing transmission of S-SSB, PSSCH and/or PSCCH, and PSFCH. More details will be described in the following text in combination with the appended drawings.

Solutions of the present disclosure may be divided into Embodiment 1 and Embodiment 2 based on which transmission (s) (e.g., SL transmission, or SL transmission and PSFCH transmission) are frequency division multiplexed (FDMed) with S-SSB within the same slot.

Embodiment 1

In Embodiment 1, at least one SL transmission (e.g., at least one of PSCCH transmission or PSSCH transmission) and an S-SSB occasion from different channels may be within the same slot. The principle of solutions in Embodiment 1 is to configure or define a first slot structure (especially AGC symbol (s) ) for an S-SSB occasion based on a second slot structure for an SL transmission in the slot. The UE behaviors for S-SSB transmission may be based on the first slot structure. The UE behaviors for SL transmission may be based on the second slot structure. Embodiment 1 may be divided into Embodiment 1-1, Embodiment 1-2, and Embodiment 1-3.

Embodiment 1-1

In Embodiment 1-1, only one candidate starting symbol is permitted (e.g., configured or pre-configured) for an SL transmission within the same slot for an S-SSB occasion. The solutions provided in Embodiment 1-1 may reduce the impact (e.g., AGC issue) from the SL transmission starting from the 2^nd starting symbol to the S-SSB transmission.

For example, an S-SSB occasion on a first channel and an SL transmission on a second channel which is different from the first channel may be within a same slot. In some cases, the first channel may be an anchor channel (i.e., anchor RB set) , and the second channel may be a non-anchor channel (i.e., non-anchor RB set) . As an example, the anchor channel may refer to a channel where S-SSB indicated by sl-AbsoluteFrequencySSB-r16 as specified in 3GPP standard documents locates. As another example, the anchor channel may be defined as a channel on which default S-SSB occasions locate. Accordingly, non-anchor channel (s) may refer to the channel (s) other than the anchor channel.

In such example, the second slot structure for the SL transmission may include only one candidate starting symbol (which is also the AGC symbol) for the SL transmission in the slot. In some implementations, the candidate starting symbol may be one of a first symbol, a second symbol, a third symbol, a fourth symbol, a fifth symbol, a sixth symbol, or a seventh symbol in the slot (e.g., configured or pre-configured from symbols {#0, #1, #2, #3, #4, #5, #6} ) .

The first slot structure for the S-SSB occasion may be based on the second slot structure for the SL transmission. For example, to solve the AGC issue, the first slot structure may include an AGC symbol which is aligned with the candidate starting symbol (i.e., the AGC symbol) for the SL transmission. The AGC symbol in the first slot structure for the S-SSB occasion may be a duplication of a next PSBCH symbol within the S-SSB occasion.

As an example, when the candidate starting symbol for the SL transmission is the first symbol (e.g., symbol #0) in the slot, the AGC symbol for the S-SSB occasion is also the first symbol in the slot, and then the first slot structure for the S-SSB occasion may be the same as that in Figure 2A. As another example, when the candidate starting symbol for the SL transmission is symbol #x in the slot, wherein x is from {1, 2, 3, 4, 5, 6} , in addition to symbol #0 as shown in Figure 2A, the first slot structure for the S-SSB occasion may also include symbol #x as an additional AGC symbol. In such example, except for the two AGC symbols (i.e., symbol #0 and symbol #x) and the gap symbol in the S-SSB occasion, S-PSS, S-SSS, and PSBCH may be sequentially carried (or arranged) in the remaining symbols in the S-SSB occasion, and each AGC symbol is a duplication (e.g., a copy) of its next or closest PSBCH symbol (not an AGC symbol) .

Figures 3A and 3B illustrate exemplary slot structures for S-SSB occasions and SL transmissions in accordance with Embodiment 1-1.

Figure 3A illustrates three RB sets (i.e., channels) , e.g., RB set #j, RB set #j+1, and RB set #j+2, and three slots (e.g., slot #i, slot #i+1, and slot #i+2) as an example. The RB set #j is an anchor RB set. For simplicity, Figure 3A illustrates three adjacent RB sets. It is contemplated that the RB sets may be not adjacent. An S-SSB occasion may be on RB set #j, and two SL transmissions may be on RB set #j+1 and RB set #j+2, respectively. The S-SSB occasion and the two SL transmissions are in the same slot, i.e., slot #i+1.

In the example shown in Figure 3A, the second slot structure for an SL transmission in slot #i+1 includes only one candidate starting symbol, which is symbol #0. Thus, the first slot structure for the S-SSB occasion includes symbol #0 as an AGC symbol, which is a duplication (e.g., a copy) of a next PSBCH symbol (i.e., symbol #5) .

Figure 3B also illustrates three RB sets (i.e., channels) , e.g., RB set #j, RB set #j+1, and RB set #j+2, and three slots (e.g., slot #i, slot #i+1, and slot #i+2) as an example. The RB set #j is an anchor RB set. For simplicity, Figure 3B illustrates three adjacent RB sets. It is contemplated that the RB sets may be not adjacent. An S-SSB occasion may be on RB set #j, and two SL transmissions may be on RB set #j+1 and RB set #j+2, respectively. The S-SSB occasion and the two SL transmissions are in the same slot, slot #i+1.

In the example shown in Figure 3B, the second slot structure for an SL transmission in slot #i+1 includes only one candidate starting symbol, which is symbol #2. Then, in addition to symbol #0 as an AGC symbol, the first slot structure for the S-SSB occasion also includes symbol #2 as another AGC symbol.

Except for symbol #0, symbol #2, and symbol #13 (which is a gap symbol) , S-PSS, S-SSS, and PSBCH are sequentially carried in the remaining symbols in the S-SSB occasion. For example, symbols #1 and #3 may include (or carry) S-PSS, symbols #4 and #5 may include S-SSS, and symbols #6 through #12 may include PSBCH. Symbol #0 is a duplication (e.g., a copy) of a next PSBCH symbol (i.e., symbol #6) , and symbol #2 is a duplication (e.g., a copy) of a next PSBCH symbol (i.e., symbol #6) .

In Embodiment 1-1, if a UE is a transmitting UE which intends to perform an SL transmission on the second channel in the slot, the UE may perform a channel access procedure (e.g., Type-1 dynamic channel access procedure or Type-2 dynamic channel access procedure as described above) on the second channel before the candidate starting symbol of the slot, and perform the SL transmission in the case that the second channel is available (e.g., based on a successful channel access procedure) for performing the SL transmission.

If a UE is a transmitting UE which intends to transmit an S-SSB on the first channel in the slot, the UE may perform a channel access procedure (e.g., Type-1 dynamic channel access procedure or Type-2 dynamic channel access procedure as described above) before the slot, and transmit the S-SSB in the case that the first channel is available (e.g., based on a successful channel access procedure) for transmitting the S-SSB.

If a UE is a receiving UE which intends to receive an SL transmission on the second channel in the slot, the UE may monitor the AGC symbol (i.e., the candidate starting symbol) for the SL transmission in the slot. In some cases, the UE may tune AGC based on the monitored AGC symbol.

If a UE is a receiving UE which intends to receive an S-SSB transmission on the first channel in the slot, the UE may monitor the AGC symbol (s) as described above in the S-SSB occasion. For example, the UE may monitor symbol #0 when the candidate starting symbol for the SL transmission is symbol #0, and may monitor symbol #0 and symbol #x when the candidate starting symbol for the SL transmission is symbol #x. In some cases, the UE may tune AGC based on the monitored AGC symbol (s) .

Embodiment 1-2

In Embodiment 1-2, two candidate starting symbols with up to two AGC symbols are configured or pre-configured for an SL transmission within the same slot for an S-SSB occasion. The solutions provided in Embodiment 1-2 may reduce the impact (e.g., AGC issue) from the SL transmission to the S-SSB transmission.

For example, an S-SSB occasion on a first channel and an SL transmission on a second channel which is different from the first channel may be within a same slot. In some cases, the first channel may be an anchor channel (i.e., anchor RB set) , and the second channel may be a non-anchor channel (i.e., non-anchor RB set) .

In such example, the second slot structure for the SL transmission may include a first candidate starting symbol and a second candidate starting symbol with up to two AGC symbols for an SL transmission in the slot. That is, a transmission starting with the first candidate starting symbol may have two AGC symbols in the slot, which are aligned with the first and second candidate starting symbols, respectively; while a transmission starting with the second candidate starting symbol may have only one AGC symbol (i.e., the second candidate starting symbol) in the slot. In some implementations, the first candidate starting symbol may be one of a first symbol, a second symbol, a third symbol, a fourth symbol, a fifth symbol, a sixth symbol, or a seventh symbol in the slot (e.g., configured or pre-configured from symbols {#0, #1, #2, #3, #4, #5, #6} ) , and the second candidate starting symbol may be one of a fourth symbol, a fifth symbol, a sixth symbol, a seventh symbol, or an eighth symbol in the slot (e.g., configured or pre-configured from symbols {#3, #4, #5, #6, #7} ) .

The first slot structure for the S-SSB occasion may be based on the second slot structure for the SL transmission. For example, to solve the AGC issue, the first slot structure may include a first AGC symbol which is aligned with the first candidate starting symbol and a second AGC symbol which is aligned with the second candidate starting symbol.

As an example, the first candidate starting symbol may be the first symbol (e.g., symbol #0) in the slot, and the second candidate starting symbol may be one of a sixth symbol, a seventh symbol, or an eighth symbol (e.g., symbol #5, symbol #6, or symbol #7) in the slot. In such example, the first slot structure for the S-SSB occasion may include two AGC symbols which are aligned with the first and second candidate starting symbols, respectively. Except for the two AGC symbols and the gap symbol in the S-SSB occasion, S-PSS, S-SSS, and PSBCH may be sequentially carried in the remaining symbols in the S-SSB occasion, and each AGC symbol is a duplication (e.g., a copy) of its next PSBCH symbol (not an AGC symbol) .

As another example, the first candidate starting symbol may be configured or pre-configured from symbols {#1, #2, #3, #4, #5, #6} in the slot, and the second candidate starting symbol may be configured or pre-configured from symbols {#3, #4, #5, #6, #7} in the slot. In such example, the first slot structure for the S-SSB occasion may include three AGC symbols, i.e., symbol #0, a first AGC symbol aligned with the first candidate starting symbol, and a second AGC symbol aligned with the second candidate starting symbol. Except for the three AGC symbols and the gap symbol in the S-SSB occasion, S-PSS, S-SSS, and PSBCH may be sequentially carried in the remaining symbols in the S-SSB occasion, and each AGC symbol is a duplication (e.g., a copy) of its next PSBCH symbol (not an AGC symbol) .

Figure 4 illustrates exemplary slot structures for an S-SSB occasion and SL transmissions in accordance with Embodiment 1-2.

Figure 4 illustrates three RB sets (i.e., channels) , e.g., RB set #j, RB set #j+1, and RB set #j+2, and three slots (e.g., slot #i, slot #i+1, and slot #i+2) as an example. The RB set #j is an anchor RB set. For simplicity, Figure 4 illustrates three adjacent RB sets. It is contemplated that the RB sets may be not adjacent. An S-SSB occasion may be on RB set #j, and two SL transmissions may be on RB set #j+1 and RB set #j+2, respectively. The S-SSB occasion and the two SL transmissions are in the same slot, i.e., slot #i+1.

In the example shown in Figure 4, the second slot structure for an SL transmission in slot #i+1 includes a first candidate starting symbol (e.g., symbol #0) and a second candidate starting symbol (e.g., symbol #5) . In RB set #j+2, the SL transmission may start from the first candidate starting symbol based on a successful channel access procedure before the first candidate starting symbol. In RB set #j+1, the SL transmission may start from the second candidate starting symbol in response to that a channel access procedure before the first candidate starting symbol fails but a channel access procedure before the second candidate starting symbol is successful.

Accordingly, the first slot structure for the S-SSB occasion includes symbol #0 and symbol #5 as two AGC symbols. Except for symbol #0, symbol #5, and symbol #13 (which is a gap symbol) , S-PSS, S-SSS, and PSBCH are sequentially carried in the remaining symbols in the S-SSB occasion. For example, symbols #1 and #2 may include S-PSS, symbols #3 and #4 may include S-SSS, and symbols #6 through #12 may include PSBCH. Symbol #0 is a duplication (e.g., a copy) of a next PSBCH symbol (i.e., symbol #6) , and symbol #5 is a duplication (e.g., a copy) of a next PSBCH symbol (i.e., symbol #6) .

In Embodiment 1-2, if a UE is a transmitting UE which intends to perform an SL transmission on the second channel in the slot, the UE may perform a channel access procedure (e.g., Type-1 dynamic channel access procedure or Type-2 dynamic channel access procedure as described above) on the second channel. If the second channel is available before the first candidate starting symbol (e.g., based on a successful channel access procedure) , the UE may perform the SL transmission from the first candidate starting symbol. Otherwise, the UE may continue the channel access procedure or start another channel access procedure, and in the case that the second channel is available before the second candidate starting symbol (e.g., based on a successful channel access procedure) , the UE may perform the SL transmission from the second candidate starting symbol.

If a UE is a receiving UE which intends to receive an SL transmission on the second channel in the slot, the UE may monitor the two AGC symbols (i.e., the first candidate starting symbol and the second candidate starting symbol) for the SL transmission in the slot. In some cases, the UE may tune AGC based on the monitored two AGC symbols.

If a UE is a receiving UE which intends to receive an S-SSB transmission on the first channel in the slot, the UE may monitor the two (e.g., when the first candidate starting symbol for the SL transmission is symbol #0) or three (e.g., when the first candidate starting symbol for the SL transmission is not symbol #0) AGC symbols as described above in the S-SSB occasion. In some cases, the UE may tune AGC based on the monitored two or three AGC symbols.

Embodiment 1-3

In Embodiment 1-3, two candidate starting symbols with only one AGC symbol are configured or pre-configured for an SL transmission within the same slot for an S-SSB occasion. The solutions provided in Embodiment 1-3 may reduce the impact (e.g., AGC issue) from the SL transmission to the S-SSB transmission.

For example, an S-SSB occasion on a first channel and an SL transmission on a second channel which is different from the first channel may be within a same slot. In some cases, the first channel may be an anchor channel (i.e., anchor RB set) , and the second channel may be a non-anchor channel (i.e., non-anchor RB set)

In such example, the second slot structure for the SL transmission may include a first candidate starting symbol and a second candidate starting symbol with only one AGC symbol for an SL transmission in the slot. That is, for an SL transmission starting from the first candidate starting symbol, the first candidate starting symbol is used as the AGC symbol; and for an SL transmission starting from the second candidate starting symbol, the second candidate starting symbol is used as the AGC symbol. In some implementations, the first candidate starting symbol may be one of a first symbol, a second symbol, a third symbol, a fourth symbol, a fifth symbol, a sixth symbol, or a seventh symbol in the slot (e.g., configured or pre-configured from symbols {#0, #1, #2, #3, #4, #5, #6} ) , and the second candidate starting symbol may be one of a fourth symbol, a fifth symbol, a sixth symbol, a seventh symbol, or an eighth symbol in the slot (e.g., configured or pre-configured from symbols {#3, #4, #5, #6, #7} ) .

The first slot structure for the S-SSB occasion may be based on the second slot structure for the SL transmission. For example, to solve the AGC issue, the first slot structure may include an AGC symbol which is aligned with the first candidate starting symbol for the SL transmission. The location of the AGC symbol and the first slot structure for the S-SSB occasion may be determined according to the same methods as those described in Embodiment 1-1. Thus, details are omitted here for simplicity.

In Embodiment 1-3, if a UE is a transmitting UE which intends to perform an SL transmission on the second channel in the slot, the UE may perform a channel access procedure (e.g., Type-1 dynamic channel access procedure or Type-2 dynamic channel access procedure as described above) on the second channel. In the case that the second channel is available before the first candidate starting symbol (e.g., based on a successful channel access procedure) , the UE may perform the SL transmission from the first candidate starting symbol.

If the second channel is not available before the first candidate starting symbol, to protect the S-SSB receiver, the UE may monitor the S-SSB occasion on the first channel in the slot. In response to at least not detecting S-SSB transmission within the slot and the second channel being available (e.g., based on a successful channel access procedure before the second candidate starting symbol) for performing the SL transmission, the UE may perform the SL transmission from the second candidate starting symbol in the slot. For example, the UE may perform the SL transmission from the second candidate starting symbol in the slot in response to not detecting S-SSB transmission within the slot, not detecting an SL transmission starting from the first candidate starting symbol within the slot (as specified in 3GPP) , and the second channel being available.

Figures 5A and 5B illustrate exemplary slot structures for S-SSB occasions and SL transmissions in accordance with Embodiment 1-3.

Figure 5A illustrates three RB sets (i.e., channels) , e.g., RB set #j, RB set #j+1, and RB set #j+2, and three slots (e.g., slot #i, slot #i+1, and slot #i+2) as an example. The RB set #j is an anchor RB set. For simplicity, Figure 5A illustrates three adjacent RB sets. It is contemplated that the RB sets may be not adjacent. An S-SSB occasion may be on RB set #j in slot #i+1.

In the example shown in Figure 5A, the second slot structure for an SL transmission in slot #i+1 includes a first candidate starting symbol (e.g., symbol #0) and a second candidate starting symbol (e.g., symbol #5) .

Accordingly, the first slot structure for the S-SSB occasion includes symbol #0 as an AGC symbol. Except for symbol #0 and symbol #13 (which is a gap symbol) , S-PSS, S-SSS, and PSBCH are sequentially carried in the remaining symbols in the S-SSB occasion. For example, symbols #1 and #2 may include S-PSS, symbols #3 and #4 may include S-SSS, and symbols #5 through #12 may include PSBCH. Symbol #0 is a duplication (e.g., a copy) of a next PSBCH symbol (i.e., symbol #5) .

On RB set #j+2, an SL transmission may start from the first candidate starting symbol in slot #i+1 based on a successful channel access procedure before the first candidate starting symbol.

In the example shown in Figure 5A, on RB set #j+1, a UE may determine that the channel is not available before the first candidate starting symbol in slot #i+1, and thus it may not perform the SL transmission from the first candidate starting symbol in slot #i+1. The UE may monitor the S-SSB occasion on RB set #j in slot #i+1. In the example as shown, the UE detects the S-SSB transmission within slot #i+1 and an SL transmission starting from the first candidate starting symbol within slot #i+1, and thus it also does not transmit the SL transmission from the second candidate starting symbol in slot #i+1.

In Figure 5B, the second slot structure for an SL transmission in slot #i+1 and the first slot structure for an S-SSB occasion in slot #i+1 are the same as those in Figure 5A. However, there is no SL transmission on RB set #j+2 in slot #i+1, and there is no S-SSB transmission on RB set #j in slot #i+1. On RB set #j+1, a UE may determine that the channel is not available before the first candidate starting symbol in slot #i+1, and thus it may not perform the SL transmission from the first candidate starting symbol in slot #i+1. The UE may monitor the S-SSB occasion on RB set #j in slot #i+1. Different from the case shown in Figure 5A, no S-SSB transmission is detected within slot #i+1. In addition, no SL transmission starting from the first candidate starting symbol is detected within slot #i+1. Thus, the UE may perform the SL transmission from the second candidate starting symbol in slot #i+1 in response to the channel being available for performing the SL transmission (e.g., based on a successful channel access procedure before the second candidate starting symbol in slot #i+1) .

The examples of Figures 5A and 5B illustrate that the first candidate starting symbol for an SL transmission is symbol #0, and thus the first slot structure for the S-SSB occasion includes only one AGC symbol aligned with symbol #0. In some other examples, the first candidate starting symbol for an SL transmission may be not symbol #0. In such examples, the first slot structure for the S-SSB occasion may include two AGC symbols, i.e., symbol #0 and an AGC symbol aligned with the first candidate starting symbol.

In Embodiment 1-3, if a UE is a transmitting UE which intends to transmit S-SSB on the first channel in the slot, the UE may perform a channel access procedure (e.g., Type-1 dynamic channel access procedure or Type-2 dynamic channel access procedure as described above) before the slot, and transmit the S-SSB in the case that the first channel is available (e.g., based on a successful channel access procedure) for transmitting the S-SSB.

If a UE is a receiving UE which intends to receive an SL transmission on the second channel in the slot, the UE may monitor the first candidate starting symbol and the second candidate starting symbol in the slot. Either the first candidate starting symbol or the second candidate starting symbol may be an AGC symbol. In some cases, the UE may tune AGC based on the monitored AGC symbol.

If a UE is a receiving UE which intends to receive an S-SSB transmission on the first channel in the slot, the UE may monitor the one (e.g., when the first candidate starting symbol for the SL transmission is symbol #0) or two (e.g., when the first candidate starting symbol for the SL transmission is not symbol #0) AGC symbols as described above in the S-SSB occasion. In some cases, the UE may tune AGC based on the monitored one or two AGC symbols.

Embodiment 2

In Embodiment 2, at least one additional transmission over SL and an S-SSB occasion from different channels may be within the same slot. The additional transmission over SL in Embodiment 2 may include both an SL transmission (e.g., at least one of PSCCH transmission or PSSCH transmission) and a PSFCH transmission.

The principle of solutions in Embodiment 2 is to configure or define a first slot structure (especially AGC symbol (s) ) for an S-SSB occasion based on a second slot structure for an additional transmission over SL in the slot. The UE behaviors for S-SSB transmission may be based on the first slot structure. The UE behaviors for the additional transmission over SL may be based on the second slot structure. The solutions provided by Embodiment 2 may reduce the impact (e.g., AGC issue) from the SL transmission and the PSFCH transmission to the S-SSB transmission.

For example, an S-SSB occasion on a first channel and an additional transmission over SL including an SL transmission and a PSFCH transmission on a second channel which is different from the first channel may be within a same slot. In some cases, the first channel may be an anchor channel (i.e., anchor RB set) , and the second channel may be a non-anchor channel (i.e., non-anchor RB set) .

In such example, the second slot structure for the additional transmission over SL may include a first AGC symbol (i.e., a candidate starting symbol) for the SL transmission in the slot and a second AGC symbol (i.e., a starting symbol) for the PSFCH transmission in the slot. In some implementations, the first AGC symbol may be one of a first symbol, a second symbol, a third symbol, a fourth symbol, a fifth symbol, a sixth symbol, or a seventh symbol in the slot (e.g., configured or pre-configured from symbols {#0, #1, #2, #3, #4, #5, #6} ) , and the second AGC symbol for the PSFCH transmission may be configured or pre-configured as specified in 3GPP standard documents, e.g., symbol #11 in the slot.

The first slot structure for the S-SSB occasion may be based on the second slot structure for the additional transmission over SL. For example, to solve the AGC issue, the first slot structure may include a third AGC symbol which is aligned with the first AGC symbol in the second slot structure, and a fourth AGC symbol which is aligned with the second AGC symbol in the second slot structure.

In some cases, the second slot structure for the additional transmission over SL may include a first gap symbol between the SL transmission and the PSFCH transmission in the slot. In such cases, the first slot structure for the S-SSB occasion may include a second gap symbol or a fifth AGC symbol which is aligned with the first gap symbol.

Figures 6A and 6B illustrate exemplary slot structures for S-SSB occasions, SL transmissions, and PSFCH transmissions in accordance with Embodiment 2.

Figure 6A illustrates three RB sets (i.e., channels) , e.g., RB set #j, RB set #j+1, and RB set #j+2, and three slots (e.g., slot #i, slot #i+1, and slot #i+2) as an example. The RB set #j is an anchor RB set. For simplicity, Figure 6A illustrates three adjacent RB sets. It is contemplated that the RB sets may be not adjacent. An S-SSB occasion may be on RB set #j, and two additional transmissions over SL may be on RB set #j+1 and RB set #j+2, respectively, wherein each additional transmission over SL may include an SL transmission and an PSFCH transmission. The S-SSB occasion and the two additional transmissions over SL are in the same slot, i.e., slot #i+1.

In the example shown in Figure 6A, the second slot structure for the additional transmission over SL includes a first AGC symbol (e.g., symbol #0) for an SL transmission, a second AGC symbol (e.g., symbol #11) for a PSFCH transmission, and a gap symbol (i.e., symbol #10) between the SL transmission and the PSFCH transmission.

Accordingly, the first slot structure for the S-SSB occasion includes symbol #0 and symbol #11 as two AGC symbols, and also includes symbol #10 as a gap symbol. Except for symbol #0, symbol #10, symbol #11, and symbol #13 (which is a gap symbol) , S-PSS, S-SSS, and PSBCH are sequentially carried in the remaining symbols in the S-SSB occasion. For example, symbols #1 and #2 may include S-PSS, symbols #3 and #4 may include S-SSS, and symbols #5 through #9 and symbol #12 may include PSBCH. Symbol #0 is a duplication (e.g., a copy) of a next PSBCH symbol (i.e., symbol #5) , and symbol #11 is a duplication (e.g., a copy) of a next PBSCH symbol (i.e., symbol #12) .

In the example of Figure 6A, the first AGC symbol for the SL transmission is symbol #0, and thus the first slot structure for the S-SSB occasion includes two AGC symbols. In some other examples, the first AGC symbol for the SL transmission may be not symbol #0. In such examples, the first slot structure for the S-SSB occasion may include three AGC symbols, i.e., symbol #0, a third AGC symbol which is aligned with the first AGC symbol for the SL transmission, and a fourth AGC symbol which is aligned with the second AGC symbol for the PSFCH transmission.

In Figure 6B, the second slot structure for the additional transmission over SL in slot #i+1 is the same as that in Figure 6A. The difference from Figure 6A lies in that: in Figure 6B, the first slot structure for the S-SSB occasion further includes a fifth AGC symbol (i.e., symbol #10) which is aligned with the gap symbol (i.e., symbol #10) between the SL transmission and the PSFCH transmission. That is, the first slot structure for the S-SSB occasion in Figure 6B includes three AGC symbols, i.e., symbol #0, symbol #10, and symbol #11. Symbol #0 is a duplication (e.g., a copy) of a next PSBCH symbol (i.e., symbol #5) , symbol #10 is a duplication (e.g., a copy) of a next PSBCH symbol (i.e., symbol #12) , and symbol #11 is a duplication (e.g., a copy) of a next PSBCH symbol (i.e., symbol #12) .

In the example of Figure 6B, the first AGC symbol for the SL transmission is symbol #0, and thus the first slot structure for the S-SSB occasion includes three AGC symbols. In some other examples, the first AGC symbol for the SL transmission may be not symbol #0. In such examples, the first slot structure for the S-SSB occasion may include fourth AGC symbols, i.e., symbol #0, a third AGC symbol which is aligned with the first AGC symbol for the SL transmission, a fourth AGC symbol which is aligned with the second AGC symbol for the PSFCH transmission, and a fifth AGC symbol which is aligned with the gap symbol between the SL transmission and the PSFCH transmission.

In Embodiment 2, if a UE is a transmitting UE which intends to perform an SL transmission on the second channel in the slot, the UE may perform a channel access procedure (e.g., Type-1 dynamic channel access procedure or Type-2 dynamic channel access procedure as described above) on the second channel before its candidate starting symbol (i.e., the first AGC symbol) , and perform the SL transmission in the case that the second channel is available (e.g., based on a successful channel access procedure) for performing the SL transmission.

If a UE is a transmitting UE which intends to perform a PSFCH transmission on the second channel in the slot, the UE may perform a channel access procedure (e.g., Type-1 dynamic channel access procedure or Type-2 dynamic channel access procedure as described above) on the second channel before its starting symbol (i.e., the second AGC symbol) , and perform the PSFCH transmission in the case that the second channel is available (e.g., based on a successful channel access procedure) for performing the PSFCH transmission.

If a UE is a transmitting UE which intends to transmit S-SSB on the first channel in the slot, the UE may perform a channel access procedure (e.g., Type-1 dynamic channel access procedure or Type-2 dynamic channel access procedure as described above) before the slot, and transmit the S-SSB in the case that the first channel is available (e.g., based on a successful channel access procedure) for transmitting the S-SSB.

If a UE is a receiving UE which intends to receive an SL transmission and/or a PSFCH on the second channel in the slot, the UE may monitor the first AGC symbol and/or the second AGC symbol in the slot. In some cases, the UE may tune AGC based on the monitored AGC symbol (s) .

If a UE is a receiving UE which intends to receive an S-SSB transmission on the first channel in the slot, the UE may monitor the two, three, or fourth AGC symbols as described above in the S-SSB occasion. In some cases, the UE may tune AGC based on the monitored two, three, or fourth AGC symbols.

Figure 7 illustrates a flowchart of an exemplary method in accordance with aspects of the present disclosure. The operations of the method illustrated in Figure 7 may be performed by a UE which intends to transmit S-SSB (e.g., UE 104 in Figure 1) as described herein or other apparatus with the like functions. In some implementations, the UE may execute a set of instructions to control functional elements of the UE to perform the described operations or functions.

As shown in Figure 7, in step 702, the UE may select an S-SSB occasion in a slot. The first slot structure for the S-SSB occasion is based on a second slot structure for an additional transmission over SL in the slot, wherein the S-SSB occasion is on a first channel and the additional transmission over SL is on a second channel.

In some embodiments, the UE may obtain the first slot structure based on configuration (i.e., the first slot structure is configured for the UE) . The first slot structure being configured for the UE refers to that: the first slot structure may be transmitted by e.g. a BS (e.g., NE 102 as shown in Figure 1) to the UE via at least one of: a SIB message, a MIB message, an RRC signaling, a MAC CE, or DCI, such that the UE may receive the first slot structure from the BS.

In some embodiments, the UE may obtain the first slot structure based on pre-configuration, definition, or pre-definition (i.e., the first slot structure is pre-configured, defined, or pre-defined for the UE) . The first slot structure being pre-configured, defined, or pre-defined for the UE refers to that: the first slot structure may be hard-wired into the UE or stored on a subscriber identity module (SIM) or universal subscriber identity module (USIM) card for the UE, such that the UE may obtain the first slot structure within the UE.

In step 704, the UE may transmit S-SSB on the selected S-SSB occasion in the case that the first channel is available for transmitting the S-SSB.

In some embodiments, the additional transmission over SL in the slot may be an SL transmission. The second slot structure for the additional transmission over SL may include only one candidate starting symbol for the SL transmission in the slot, and the first slot structure for the S-SSB occasion may include an AGC symbol which is aligned with the candidate starting symbol. Non-limiting examples for the first slot structure and the second slot structure in such embodiments may refer to Embodiment 1-1.

In an example, in the case that the candidate starting symbol is one of a first symbol, a second symbol, a third symbol, a fourth symbol, a fifth symbol, a sixth symbol, or a seventh symbol in the slot, the AGC symbol is a duplication of a next PSBCH symbol within the S-SSB occasion,

In some embodiments, the additional transmission over SL in the slot may be an SL transmission. The second slot structure for the additional transmission over SL may include a first candidate starting symbol and a second candidate starting symbol with up to two AGC symbols for the SL transmission in the slot, and the first slot structure for the S-SSB occasion may include a first AGC symbol which is aligned with the first candidate starting symbol and a second AGC symbol which is aligned with the second candidate starting symbol. Non-limiting examples for the first slot structure and the second slot structure in such embodiments may refer to Embodiment 1-2.

In an example, the first candidate starting symbol is the first symbol in the slot, and the second candidate starting symbol is one of a sixth symbol, a seventh symbol, or an eighth symbol in the slot.

In some embodiments, the additional transmission over SL in the slot may be an SL transmission. The second slot structure for the additional transmission over SL may include a first candidate starting symbol and a second candidate starting symbol with only one AGC symbol for the SL transmission in the slot, and the first slot structure for the S-SSB occasion may include an AGC symbol which is aligned with the first candidate starting symbol. Non- limiting examples for the first slot structure and the second slot structure in such embodiments may refer to Embodiment 1-3.

In some embodiments, the additional transmission over SL in the slot may include an SL transmission and a PSFCH transmission. The second slot structure for the additional transmission over SL may include a first AGC symbol for the SL transmission in the slot and a second AGC symbol for the PSFCH transmission in the slot, and the first slot structure for the S-SSB occasion may include a third AGC symbol which is aligned with the first AGC symbol and a fourth AGC symbol which is aligned with the second AGC symbol. Non-limiting examples for the first slot structure and the second slot structure in such embodiments may refer to Embodiment 2.

In an example, the second slot structure for the additional transmission over SL may further include a first gap symbol between the SL transmission and the PSFCH transmission in the slot, and the first slot structure for the S-SSB occasion may further include a second gap symbol or a fifth AGC symbol which is aligned with the first gap symbol.

Figure 8 illustrates a flowchart of an exemplary method in accordance with aspects of the present disclosure. The operations of the method illustrated in Figure 8 may be performed by a UE which intends to receive S-SSB (e.g., UE 104 in Figure 1) as described herein or other apparatus with the like functions. In some implementations, the UE may execute a set of instructions to control functional elements of the UE to perform the described operations or functions.

As shown in Figure 8, in step 802, the UE may monitor one or more AGC symbols within an S-SSB occasion in a slot. The first slot structure for the S-SSB occasion is based on a second slot structure for an additional transmission over SL in the slot, wherein the S-SSB occasion is on a first channel and the additional transmission over SL is on a second channel.

In some embodiments, the UE may obtain the first slot structure based on configuration (i.e., the first slot structure is configured for the UE) . In some embodiments, the UE may obtain the first slot structure based on pre-configuration, definition, or pre-definition (i.e., the first slot structure is pre-configured, defined, or pre-defined for the UE) .

In step 804, the UE may tune AGC based on the monitored one or more AGC symbols.

In some embodiments, the additional transmission over SL in the slot may be an SL transmission. The second slot structure for the additional transmission over SL may include only one candidate starting symbol for the SL transmission in the slot, and the first slot structure for the S-SSB occasion may include an AGC symbol which is aligned with the candidate starting symbol. In such embodiments, the monitored one or more AGC symbols may include at least the AGC symbol in the first slot structure. Non-limiting examples for the first slot structure and the second slot structure in such embodiments may refer to Embodiment 1-1.

In some embodiments, the additional transmission over SL in the slot may be an SL transmission. The second slot structure for the additional transmission over SL may include a first candidate starting symbol and a second candidate starting symbol with up to two AGC symbols for the SL transmission in the slot, and the first slot structure for the S-SSB occasion may include a first AGC symbol which is aligned with the first candidate starting symbol and a second AGC symbol which is aligned with the second candidate starting symbol. In such embodiments, the monitored one or more AGC symbols may include at least the first AGC symbol and the second AGC symbol. Non-limiting examples for the first slot structure and the second slot structure in such embodiments may refer to Embodiment 1-2.

In some embodiments, the additional transmission over SL in the slot may be an SL transmission. The second slot structure for the additional transmission over SL may include a first candidate starting symbol and a second candidate starting symbol with only one AGC symbol for the SL transmission in the slot, and the first slot structure for the S-SSB occasion may include an AGC symbol which is aligned with the first candidate starting symbol. In such embodiments, the monitored one or more AGC symbols may include at least the AGC symbol in the first slot structure. Non-limiting examples for the first slot structure and the second slot structure in such embodiments may refer to Embodiment 1-3.

In some embodiments, the additional transmission over SL in the slot may include an SL transmission and a PSFCH transmission. The second slot structure for the additional transmission over SL may include a first AGC symbol for the SL transmission in the slot and a second AGC symbol for the PSFCH transmission in the slot, and the first slot structure for the S-SSB occasion may include a third AGC symbol which is aligned with the first AGC symbol and a fourth AGC symbol which is aligned with the second AGC symbol. In such embodiments, the monitored one or more AGC symbols may include at least the third AGC symbol and the fourth AGC symbol. Non-limiting examples for the first slot structure and the second slot structure in such embodiments may refer to Embodiment 2.

Figure 9 illustrates a flowchart of an exemplary method in accordance with aspects of the present disclosure. The operations of the method illustrated in Figure 9 may be performed by a UE which intends to transmit an SL transmission (e.g., UE 104 in Figure 1) as described herein or other apparatus with the like functions. In some implementations, the UE may execute a set of instructions to control functional elements of the UE to perform the described operations or functions.

As shown in Figure 9, in step 902, the UE may monitor an S-SSB occasion in a slot. A first slot structure for the S-SSB occasion is based on a second slot structure for an SL transmission in the slot, wherein the S-SSB occasion is on a first channel and the SL transmission is on a second channel. All the definitions regarding the first slot structure and the second slot structures provided in Embodiment 1-3 may apply here. For example, the second slot structure may include a first candidate starting symbol and a second candidate starting symbol for the SL transmission.

In step 904, in response to at least not detecting S-SSB transmission within the slot and the second channel being available for performing the SL transmission, the UE may perform the SL transmission from the second candidate starting symbol in the slot. Non-limiting examples of the specific operation for the UE may refer to the operation of the UE described in Embodiment 1-3.

According to some embodiments of the present application, a BS (e.g., NE 102 as shown in Figure 1) may transmit, to one or more UEs (e.g., UE 104 as shown in Figure 1) , a first slot structure for an S-SSB occasion in a slot. The first slot structure is based on a second slot structure for an additional transmission over SL in the slot, wherein the S-SSB occasion is on a first channel and the additional transmission over SL is on a second channel. Non-limiting examples for the first slot structure and the second slot structure may refer to Embodiments 1 and 2.

In an embodiment, the BS may transmit the first slot structure to one or more UEs via at least one of: a MIB message, a SIB message, an RRC signaling, a MAC CE, or DCI.

Figure 10 illustrates an example of a UE 1000 in accordance with aspects of the present disclosure. The UE 1000 may include at least one processor 1002 and at least one memory 1004. Additionally, the UE 1000 may also include one or more of at least one controller 1006 or at least one transceiver 1008. The processor 1002, the memory 1004, the controller 1006, or the transceiver 1008, or various combinations thereof or various components thereof may be examples of means for performing various aspects of the present disclosure as described herein. These components may be coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces.

The processor 1002, the memory 1004, the controller 1006, or the transceiver 1008, or various combinations or components thereof may be implemented in hardware (e.g., circuitry) . The hardware may include a processor, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , or other programmable logic device, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure.

The processor 1002 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, an ASIC, an FPGA, or any combination thereof) . In some implementations, the processor 1002 may be configured to operate the memory 1004. In some other implementations, the memory 1004 may be integrated into the processor 1002. The processor 1002 may be configured to execute computer-readable instructions stored in the memory 1004 to cause the UE 1000 to perform various functions of the present disclosure.

The memory 1004 may include volatile or non-volatile memory. The memory 1004 may store computer-readable, computer-executable code including instructions when executed by the processor 1002 cause the UE 1000 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as the memory 1004 or another type of memory. Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer.

In some implementations, the processor 1002 and the memory 1004 coupled with the processor 1002 may be configured to cause the UE 1000 to perform one or more of the functions described herein (e.g., executing, by the processor 1002, instructions stored in the memory 1004) . For example, the processor 1002 may support wireless communication at the UE 1000 in accordance with examples as disclosed herein. The UE 1000 may be configured to support a means for performing the operations of the methods described in the embodiments of the present disclosure.

As an example, the processor 1002 may be configured to cause the UE 1000 to: select an S-SSB occasion in a slot, wherein a first slot structure for the S-SSB occasion is based on a second slot structure for an additional transmission over SL in the slot, and wherein the S-SSB occasion is on a first channel and the additional transmission over SL is on a second channel; and transmit S-SSB on the selected S-SSB occasion in the case that the first channel is available for transmitting the S-SSB.

As another example, the processor 1002 may be configured to cause the UE 1000 to: monitor one or more AGC symbols within an S-SSB occasion in a slot, wherein a first slot structure for the S-SSB occasion is based on a second slot structure for an additional transmission over SL in the slot, and wherein the S-SSB occasion is on a first channel and the additional transmission over SL is on a second channel; and tune AGC based on the monitored one or more AGC symbols.

As yet another example, the processor 1002 may be configured to cause the UE 1000 to:monitor an S-SSB occasion in a slot, wherein a first slot structure for the S-SSB occasion is based on a second slot structure for an SL transmission in the slot, wherein the second slot structure includes a first candidate starting symbol and a second candidate starting symbol for the SL transmission, and wherein the S-SSB occasion is on a first channel and the SL transmission is on a second channel; and perform the SL transmission from the second candidate starting symbol in the slot in response to at least not detecting S-SSB transmission within the slot and the second channel being available for performing the SL transmission.

The controller 1006 may manage input and output signals for the UE 1000. The controller 1006 may also manage peripherals not integrated into the UE 1000. In some implementations, the controller 1006 may utilize an operating system such as or other operating systems. In some implementations, the controller 1006 may be implemented as part of the processor 1002.

In some implementations, the UE 1000 may include at least one transceiver 1008. In some other implementations, the UE 1000 may have more than one transceiver 1008. The transceiver 1008 may represent a wireless transceiver. The transceiver 1008 may include one or more receiver chains 1010, one or more transmitter chains 1012, or a combination thereof.

A receiver chain 1010 may be configured to receive signals (e.g., control information, data, packets) over a wireless medium. For example, the receiver chain 1010 may include one or more antennas for receive the signal over the air or wireless medium. The receiver chain 1010 may include at least one amplifier (e.g., a low-noise amplifier (LNA) ) configured to amplify the received signal. The receiver chain 1010 may include at least one demodulator configured to demodulate the receive signal and obtain the transmitted data by reversing the modulation technique applied during transmission of the signal. The receiver chain 1010 may include at least one decoder for decoding the demodulated signal to receive the transmitted data.

A transmitter chain 1012 may be configured to generate and transmit signals (e.g., control information, data, packets) . The transmitter chain 1012 may include at least one modulator for modulating data onto a carrier signal, preparing the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques such as amplitude modulation (AM) , frequency modulation (FM) , or digital modulation schemes like phase-shift keying (PSK) or quadrature amplitude modulation (QAM) . The transmitter chain 1012 may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over the wireless medium. The transmitter chain 1012 may also include one or more antennas for transmitting the amplified signal into the air or wireless medium.

Figure 11 illustrates an example of a processor 1100 in accordance with aspects of the present disclosure. The processor 1100 may be an example of a processor configured to perform various operations in accordance with examples as described herein. The processor 1100 may include a controller 1102 configured to perform various operations in accordance with examples as described herein. The processor 1100 may optionally include at least one memory 1104, which may be, for example, a layer 1 (L1) , layer 2 (L2) , or layer 3 (L3) cache. Additionally, or alternatively, the processor 1100 may optionally include one or more arithmetic-logic units (ALUs) 1106. One or more of these components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses) .

The processor 1100 may be a processor chipset and include a protocol stack (e.g., a software stack) executed by the processor chipset to perform various operations (e.g., receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) in accordance with examples as described herein. The processor chipset may include one or more cores, one or more caches (e.g., memory local to or included in the processor chipset (e.g., the processor 1100) or other memory (e.g., random access memory (RAM) , read-only memory (ROM) , dynamic RAM (DRAM) , synchronous dynamic RAM (SDRAM) , static RAM (SRAM) , ferroelectric RAM (FeRAM) , magnetic RAM (MRAM) , resistive RAM (RRAM) , flash memory, phase change memory (PCM) , and others) .

The controller 1102 may be configured to manage and coordinate various operations (e.g., signaling, receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) of the processor 1100 to cause the processor 1100 to support various operations in accordance with examples as described herein. For example, the controller 1102 may operate as a control unit of the processor 1100, generating control signals that manage the operation of various components of the processor 1100. These control signals include enabling or disabling functional units, selecting data paths, initiating memory access, and coordinating timing of operations.

The controller 1102 may be configured to fetch (e.g., obtain, retrieve, receive) instructions from the memory 1104 and determine subsequent instruction (s) to be executed to cause the processor 1100 to support various operations in accordance with examples as described herein. The controller 1102 may be configured to track memory address of instructions associated with the memory 1104. The controller 1102 may be configured to decode instructions to determine the operation to be performed and the operands involved. For example, the controller 1102 may be configured to interpret the instruction and determine control signals to be output to other components of the processor 1100 to cause the processor 1100 to support various operations in accordance with examples as described herein. Additionally, or alternatively, the controller 1102 may be configured to manage flow of data within the processor 1100. The controller 1102 may be configured to control transfer of data between registers, ALUs, and other functional units of the processor 1100.

The memory 1104 may include one or more caches (e.g., memory local to or included in the processor 1100 or other memory, such RAM, ROM, DRAM, SDRAM, SRAM, MRAM, flash memory, etc. ) . In some implementations, the memory 1104 may reside within or on a processor chipset (e.g., local to the processor 1100) . In some other implementations, the memory 1104 may reside external to the processor chipset (e.g., remote to the processor 1100) .

The memory 1104 may store computer-readable, computer-executable code including instructions that, when executed by the processor 1100, cause the processor 1100 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. The controller 1102 and/or the processor 1100 may be configured to execute computer-readable instructions stored in the memory 1104 to cause the processor 1100 to perform various functions. For example, the processor 1100 and/or the controller 1102 may be coupled with or to the memory 1104, the processor 1100, the controller 1102, and the memory 1104 may be configured to perform various functions described herein. In some examples, the processor 1100 may include multiple processors and the memory 1104 may include multiple memories. One or more of the multiple processors may be coupled with one or more of the multiple memories, which may, individually or collectively, be configured to perform various functions herein.

The one or more ALUs 1106 may be configured to support various operations in accordance with examples as described herein. In some implementations, the one or more ALUs 1106 may reside within or on a processor chipset (e.g., the processor 1100) . In some other implementations, the one or more ALUs 1106 may reside external to the processor chipset (e.g., the processor 1100) . One or more ALUs 1106 may perform one or more computations such as addition, subtraction, multiplication, and division on data. For example, one or more ALUs 1106 may receive input operands and an operation code, which determines an operation to be executed. One or more ALUs 1106 be configured with a variety of logical and arithmetic circuits, including adders, subtractors, shifters, and logic gates, to process and manipulate the data according to the operation. Additionally, or alternatively, the one or more ALUs 1106 may support logical operations such as AND, OR, exclusive-OR (XOR) , not-OR (NOR) , and not-AND (NAND) , enabling the one or more ALUs 1106 to handle conditional operations, comparisons, and bitwise operations.

The processor 1100 may support wireless communication in accordance with examples as disclosed herein. The processor 1100 may be configured to or operable to support a means for performing the operations of the methods described in the embodiments of the present disclosure.

As an example, the controller 1102 may be configured to cause the processor 1100 to: select an S-SSB occasion in a slot, wherein a first slot structure for the S-SSB occasion is based on a second slot structure for an additional transmission over SL in the slot, and wherein the S-SSB occasion is on a first channel and the additional transmission over SL is on a second channel; and transmit S-SSB on the selected S-SSB occasion in the case that the first channel is available for transmitting the S-SSB.

As another example, the controller 1102 may be configured to cause the processor 1100 to: monitor one or more AGC symbols within an S-SSB occasion in a slot, wherein a first slot structure for the S-SSB occasion is based on a second slot structure for an additional transmission over SL in the slot, and wherein the S-SSB occasion is on a first channel and the additional transmission over SL is on a second channel; and tune AGC based on the monitored one or more AGC symbols.

As yet another example, the controller 1102 may be configured to cause the processor 1100 to: monitor an S-SSB occasion in a slot, wherein a first slot structure for the S-SSB occasion is based on a second slot structure for an SL transmission in the slot, wherein the second slot structure includes a first candidate starting symbol and a second candidate starting symbol for the SL transmission, and wherein the S-SSB occasion is on a first channel and the SL transmission is on a second channel; and perform the SL transmission from the second candidate starting symbol in the slot in response to at least not detecting S-SSB transmission within the slot and the second channel being available for performing the SL transmission.

Figure 12 illustrates an example of a BS 1200 in accordance with aspects of the present disclosure. The BS 1200 may include at least one processor 1202 and at least one memory 1204. Additionally, the BS 1200 may also include one or more of at least one controller 1206 or at least one transceiver 1208. The processor 1202, the memory 1204, the controller 1206, or the transceiver 1208, or various combinations thereof or various components thereof may be examples of means for performing various aspects of the present disclosure as described herein. These components may be coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces.

The processor 1202, the memory 1204, the controller 1206, or the transceiver 1208, or various combinations or components thereof may be implemented in hardware (e.g., circuitry) . The hardware may include a processor, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , or other programmable logic device, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure. As an example, the processor 1202 may be configured to cause the BS 1200 to: transmit, to a UE, a first slot structure for an S-SSB occasion in a slot, wherein the first slot structure is based on a second slot structure for an additional transmission over SL in the slot, and wherein the S-SSB occasion is on a first channel and the additional transmission over SL is on a second channel.

The processor 1202 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, an ASIC, an FPGA, or any combination thereof) . In some implementations, the processor 1202 may be configured to operate the memory 1204. In some other implementations, the memory 1204 may be integrated into the processor 1202. The processor 1202 may be configured to execute computer-readable instructions stored in the memory 1204 to cause the BS 1200 to perform various functions of the present disclosure.

The memory 1204 may include volatile or non-volatile memory. The memory 1204 may store computer-readable, computer-executable code including instructions when executed by the processor 1202 cause the BS 1200 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as the memory 1204 or another type of memory. Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer.

In some implementations, the processor 1202 and the memory 1204 coupled with the processor 1202 may be configured to cause the BS 1200 to perform one or more of the functions described herein (e.g., executing, by the processor 1202, instructions stored in the memory 1204) . For example, the processor 1202 may support wireless communication at the BS 1200 in accordance with examples as disclosed herein. The BS 1200 may be configured to support a means for performing the operations of the methods described in the embodiments of the present disclosure.

The controller 1206 may manage input and output signals for the BS 1200. The controller 1206 may also manage peripherals not integrated into the BS 1200. In some implementations, the controller 1206 may utilize an operating system such as or other operating systems. In some implementations, the controller 1206 may be implemented as part of the processor 1202.

In some implementations, the BS 1200 may include at least one transceiver 1208. In some other implementations, the BS 1200 may have more than one transceiver 1208. The transceiver 1208 may represent a wireless transceiver. The transceiver 1208 may include one or more receiver chains 1210, one or more transmitter chains 1212, or a combination thereof.

A receiver chain 1210 may be configured to receive signals (e.g., control information, data, packets) over a wireless medium. For example, the receiver chain 1210 may include one or more antennas for receive the signal over the air or wireless medium. The receiver chain 1210 may include at least one amplifier (e.g., a low-noise amplifier (LNA) ) configured to amplify the received signal. The receiver chain 1210 may include at least one demodulator configured to demodulate the receive signal and obtain the transmitted data by reversing the modulation technique applied during transmission of the signal. The receiver chain 1210 may include at least one decoder for decoding the demodulated signal to receive the transmitted data.

A transmitter chain 1212 may be configured to generate and transmit signals (e.g., control information, data, packets) . The transmitter chain 1212 may include at least one modulator for modulating data onto a carrier signal, preparing the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques such as amplitude modulation (AM) , frequency modulation (FM) , or digital modulation schemes like phase-shift keying (PSK) or quadrature amplitude modulation (QAM) . The transmitter chain 1212 may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over the wireless medium. The transmitter chain 1212 may also include one or more antennas for transmitting the amplified signal into the air or wireless medium.

The description herein is provided to enable a person having ordinary skill in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to a person having ordinary skill in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

Claims

A user equipment (UE) for wireless communication, comprising:

at least one memory; and

at least one processor coupled with the at least one memory and configured to cause the UE to:

select a sidelink (SL) synchronization signal block (S-SSB) occasion in a slot, wherein a first slot structure for the S-SSB occasion is based on a second slot structure for an additional transmission over SL in the slot, and wherein the S-SSB occasion is on a first channel and the additional transmission over SL is on a second channel; and

transmit S-SSB on the selected S-SSB occasion in the case that the first channel is available for transmitting the S-SSB.
The UE of Claim 1, wherein the second slot structure includes only one candidate starting symbol for an SL transmission in the slot, and the first slot structure includes an automatic gain control (AGC) symbol which is aligned with the candidate starting symbol.
The UE of Claim 2, wherein the AGC symbol is a duplication of a next physical sidelink broadcast channel (PSBCH) symbol within the S-SSB occasion, in the case that the candidate starting symbol is one of a first symbol, a second symbol, a third symbol, a fourth symbol, a fifth symbol, a sixth symbol, or a seventh symbol in the slot.
The UE of Claim 1, wherein the second slot structure includes a first candidate starting symbol and a second candidate starting symbol with up to two AGC symbols for an SL transmission in the slot, and the first slot structure includes a first AGC symbol which is aligned with the first candidate starting symbol and a second AGC symbol which is aligned with the second candidate starting symbol.
The UE of Claim 4, wherein the first candidate starting symbol is the first symbol in the slot, and the second candidate starting symbol is one of a sixth symbol, a seventh symbol, or an eighth symbol in the slot.
The UE of Claim 1, wherein the second slot structure includes a first candidate starting symbol and a second candidate starting symbol with only one AGC symbol for an SL transmission in the slot, and the first slot structure includes an AGC symbol which is aligned with the first candidate starting symbol.
The UE of Claim 1, wherein the second slot structure includes a first AGC symbol for an SL transmission in the slot and a second AGC symbol for a physical sidelink feedback channel (PSFCH) transmission in the slot, and the first slot structure includes a third AGC symbol which is aligned with the first AGC symbol and a fourth AGC symbol which is aligned with the second AGC symbol.
The UE of Claim 7, wherein the second slot structure further includes a first gap symbol between the SL transmission and the PSFCH transmission in the slot, and the first slot structure further includes a second gap symbol or a fifth AGC symbol which is aligned with the first gap symbol.
The UE of Claim 1, wherein the first slot structure is configured or pre-configured to the UE, is defined, or is pre-defined.
A user equipment (UE) for wireless communication, comprising:

at least one memory; and

at least one processor coupled with the at least one memory and configured to cause the UE to:

monitor one or more automatic gain control (AGC) symbols within a sidelink (SL) synchronization signal block (S-SSB) occasion in a slot, wherein a first slot structure for the S-SSB occasion is based on a second slot structure for an additional transmission over SL in the slot, and wherein the S-SSB occasion is on a first channel and the additional transmission over SL is on a second channel; and

tune AGC based on the monitored one or more AGC symbols.
The UE of Claim 10, wherein the second slot structure includes only one candidate starting symbol for an SL transmission in the slot, and the first slot structure includes an AGC symbol which is aligned with the candidate starting symbol.
The UE of Claim 11, wherein the AGC symbol is a duplication of a next physical sidelink broadcast channel (PSBCH) symbol within the S-SSB occasion, in the case that the candidate starting symbol is one of a first symbol, a second symbol, a third symbol, a fourth symbol, a fifth symbol, a sixth symbol, or a seventh symbol in the slot.
The UE of Claim 10, wherein the second slot structure includes a first candidate starting symbol and a second candidate starting symbol with up to two AGC symbols for an SL transmission in the slot, and the first slot structure includes a first AGC symbol which is aligned with the first candidate starting symbol and a second AGC symbol which is aligned with the second candidate starting symbol.
The UE of Claim 13, wherein the first candidate starting symbol is the first symbol in the slot, and the second candidate starting symbol is one of a sixth symbol, a seventh symbol, or an eighth symbol in the slot.
The UE of Claim 10, wherein the second slot structure includes a first candidate starting symbol and a second candidate starting symbol with only one AGC symbol for an SL transmission in the slot, and the first slot structure includes an AGC symbol which is aligned with the first candidate starting symbol.
The UE of Claim 10, wherein the second slot structure includes a first AGC symbol for an SL transmission in the slot and a second AGC symbol for a physical sidelink feedback channel (PSFCH) transmission in the slot, and the first slot structure includes a third AGC symbol which is aligned with the first AGC symbol and a fourth AGC symbol which is aligned with the second AGC symbol.
The UE of Claim 16, wherein the second slot structure further includes a first gap symbol between the SL transmission and the PSFCH transmission in the slot, and the first slot structure further includes a second gap symbol or a fifth AGC symbol which is aligned with the first gap symbol.
A user equipment (UE) for wireless communication, comprising:

at least one memory; and

at least one processor coupled with the at least one memory and configured to cause the UE to:

monitor a sidelink (SL) synchronization signal block (S-SSB) occasion in a slot, wherein a first slot structure for the S-SSB occasion is based on a second slot structure for an SL transmission in the slot, wherein the second slot structure includes a first candidate starting symbol and a second candidate starting symbol for the SL transmission, and wherein the S-SSB occasion is on a first channel and the SL transmission is on a second channel; and

perform the SL transmission from the second candidate starting symbol in the slot in response to at least not detecting S-SSB transmission within the slot and the second channel being available for performing the SL transmission.
A base station (BS) for wireless communication, comprising:

at least one memory; and

at least one processor coupled with the at least one memory and configured to cause the BS to:

transmit, to a user equipment (UE) , a first slot structure for a sidelink (SL) synchronization signal block (S-SSB) occasion in a slot, wherein the first slot structure is based on a second slot structure for an additional transmission over SL in the slot, and wherein the S-SSB occasion is on a first channel and the additional transmission over SL is on a second channel.
The BS of Claim 19, wherein the at least one processor is configured to cause the BS to transmit the first slot structure via at least one of: a master information block (MIB) message, a system information block (SIB) message, a radio resource control (RRC) signaling, a medium access control (MAC) control element (CE) , or downlink control information (DCI) .