Sidelink unlicensed (SL-u) gap symbols and cyclic prefix extension (CPE) configuration

Abstract

To provide a user equipment (UE) and a method for enabling sidelink (SL) communication.SOLUTION: In a wireless communication network, a method for SL communications by a user equipment (UE) includes sensing an SL channel with clear channel assessment (CCA) to configure an SL unlicensed (SL-U) gap symbol and cyclic prefix extension (CPE) length, generating an SL communication by configuring a gap length based on subcarrier spacing (SCS) and a CPE having a CPE length, and transmitting the SL communication in response to acquiring the SL channel. The method further includes generating each slot with at least one gap symbol at an end portion of slot symbols when utilizing a partial bandwidth (BW) for SL communication or based on a sidelink control information (SCI) configuration.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present disclosure relates to wireless technologies for sidelink (SL) unlicensed (SL-U) configurations and gap symbol and cyclic prefix extension (CPE) configurations. [Background technology]

[0002] As the number of mobile devices in wireless networks and demand for mobile data traffic continue to increase, changes are being made to system requirements and architectures to better address current and anticipated demands. For example, some wireless communication networks (e.g., fifth-generation (5G) or new radio (NR) networks) may be developed to include UE-to-UE (U2U) relay communications or UE-to-network (NW) (U2N) relay communications. In such scenarios, path sidelink (SL) relay enhancements may be implemented. [Brief explanation of the drawings]

[0003] [Figure 1] 1 illustrates an example slot structure for sidelink (SL) communications in accordance with various aspects.

[0004] [Figure 2] 1 illustrates another example slot structure for sidelink (SL) communications in accordance with various aspects.

[0005] [Figure 3] 1 illustrates an example multi-slot structure for sidelink (SL) communications in accordance with various aspects.

[0006] [Figure 4] 1 illustrates another example multi-slot structure for sidelink (SL) communications in accordance with various aspects.

[0007] [Figure 5]1 illustrates example signaling for SL communication in accordance with various aspects.

[0008] [Figure 6] 10 illustrates another example of signaling for SL communication in accordance with various aspects.

[0009] [Figure 7] 10 illustrates another example of signaling for SL communication in accordance with various aspects.

[0010] [Figure 8] 1 illustrates an example process flow for SL communication in accordance with various aspects.

[0011] [Figure 9] FIG. 1 shows an example block diagram illustrating an example of user equipment(s) (UE) communicatively coupled to a network having network components as peer devices usable in connection with various embodiments (aspects) described herein.

[0012] [Figure 10] FIG. 1 illustrates an example simplified block diagram of a user equipment (UE) wireless communication device or other network device / component (e.g., eNB, gNB), in accordance with various aspects. DETAILED DESCRIPTION OF THE INVENTION

[0013] The following detailed description refers to the accompanying drawings. Like reference numerals in different drawings may identify the same or similar features, elements, operations, etc. Additionally, the disclosure is not limited to the following description, as other implementations may be utilized and structural or logical changes may be made without departing from the scope of the disclosure.

[0014] Various aspects are described herein, including user equipment (UE) devices that enable sidelink (SL) communications. The UE devices may be pedestrian UE (P-UE) devices, vehicle-to-everything (V2X) devices, or other UEs that may include vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-pedestrian (V2P) device communications, or other UEs operating in direct SL communications. The UEs may also include, for example, roadside units (RSUs), drones, other vehicular devices, Internet of Things (IoT) devices, or other UE devices. To meet the requirements of vehicular networks, including operation in NR-unlicensed (NR-U) networks, different types of communications are considered for new radio (NR) devices. Use cases may involve different types of communications, including V2V, V2I, V2P, V2N, etc., over SL-unlicensed (SL-U) communications channels.

[0015] Particularly in out-of-coverage scenarios or in unlicensed NR networks in SL-U, when configuring a dedicated SL channel between UEs, the initiating / initiating UE device first senses the SL channel to determine whether it is busy. Upon acquiring the SL channel using a clear channel assessment (CCA) operation, the initiating UE can provide SL control information (SCI) in two phases: a first phase SCI and a second phase SCI, which can be carried on a physical SL control channel (PSCCH) or a physical SL shared channel (PSSCH). The first phase SCI includes information for enabling sensing operations on the acquired SL channel as well as information about resource allocation. The second phase SCI can carry information for identifying and decoding the SL channel and for enabling control for a hybrid automatic repeat request (HARQ) procedure, a trigger for channel state information (CSI) feedback, or related feedback information (e.g., ACK / NACK feedback). The SL shared channel or PSSCH also carries the transport blocks (TB) of data for transmission, and the SCI further contains information for correct reception of the TB to enable the SL data to be received and properly decoded.

[0016] Additional SCI information can be configured by the initiating UE. For example, when channel occupation time (COT) sharing is signaled to enable the receiver UE to share the same COT as the initiating UE for SL transmission, various clear channel assessments (CCA) can be indicated in the SCI so that the receiver UE performs a CCA shorter than full / full CCA (e.g., Category 4 CCA). For example, by performing a shorter CCA, such as single / one-shot CCA, SL communication between paired UE devices can be maintained efficiently without wasting resources. In dynamic channel access where COT sharing is indicated by the SCI or radio resource control (RRC) configuration, the SL UE can perform one of Type 1 (full CCA with random backoff number generation) or Type 2 LBT (shorter CCA than Type 1) before SL transmission by using selected / reserved resources according to the transmission gap and listen-before-talk (LBT) sensing window.

[0017] In one aspect, a UE can sense an SL channel using CCA and, when the SL channel is acquired, generate an SL transmission by configuring a gap length in the SL slot based on the subcarrier spacing (SCS) and a CPE length with a cyclic prefix extension (CPE) length. The gap length and CPE length can be based on one or more conditions or channel types. For example, if the SCS or orthogonal frequency division multiplexing (OFDM) numerology is 60 kHz SCS, the slot gap can be configured with a gap length of up to two gap symbols. This gap length configuration can ensure the completion of CCA types for COT sharing and non-COT sharing, especially with 60 kHz SCS. The gap symbols can be adjacent to each other. Furthermore, this gap length can be configured before a physical PSFCH feedback channel (SL) transmission in a slot or multiple slots, at the end of one or more slots, or both before a PSFCH transmission and at the end of one or more slots, according to various channel and conditions. Additional aspects and details of the present disclosure are further described below with reference to the figures.

[0018] 1 illustrates an example of an SL slot for SL communication 100 in an NR unlicensed network between an initiating UE (e.g., 110-1) and a receiving UE (e.g., 110-2). As referred to herein, SL communication refers to direct communication between two or more UEs without traversing a network node or base station. An SL slot 104 includes several symbols (e.g., 14 symbols, or another number), each including a resource block (RB) spanning the vertical axis of each subchannel 102. Some symbols include a PSCCH 118 and a PSSCH 120, and the PSSCH 120 can occupy up to several physical resource blocks (PRBs) 106 (e.g., up to 10, 12, 15, 20, 25, etc. PRBs). The SL slot 104 includes resources having a PSCCH 118 and a PSSCH 120, an automatic gain control (AGC) symbol 116 as the first symbol, gap symbols 122A and 122B, and a physical SL feedback channel (SL) symbol 124. The SL slot 104 may be configured with more or fewer symbols than shown, which may be transmitted in smaller or larger time blocks in various applications, for example.

[0019] The SL slot 104 includes a first symbol comprising an AGC symbol 116, which may be a second symbol or a copy of another OFDM symbol for automatic gain control purposes such as power level control at the SL UE receiver 110-2. Subsequent symbols include a first stage (stage 1 / stage 1) SCI on the PSCCH 118 having information to enable sensing operations and relating to resource allocation for the PSSCH 120. The SCIs may include a first stage SCI on the PSCCH 118 having various information for sensing and resource mapping, as well as a second stage SCI on the PSSCH 120 that may be multiplexed with the PSCCH 118. The PSFCH 124 may be utilized to transmit HARQ feedback for ACK / NACK information from the receiver UE 110-2 to the transmitter / initiating UE 110-1 on the SL channel for unicast or groupcast communications.

[0020] SL communications for improved road safety, traffic efficiency, infotainment, or other enhancements may occur in any one of the following network coverage scenarios: 1) in-coverage, when the communicating UEs on the SL (e.g., P-UE or Vehicle UE (V-UE)) are located in the coverage of a base station (e.g., new radio gNB); 2) out-of-coverage, when all communicating UEs are outside the coverage of any base station (or gNB); or 3) partial coverage, when at least one of the UEs is in-coverage and communicatively coupled to a base station.

[0021] The SCI is further configured to include an indication (field or parameter) for enabling COT sharing, which may or may not be initiated by a base station (e.g., gNB, etc.). COT sharing may be enabled on the SL-U COT when the initiating UE has acquired an SL channel and can share any remaining resources unused after configuring resources for SL transmission with the receiving UE 110-2. The receiving UE 110-2 then transmits over the SL channel using resources similar to those indicated by the initiating UE 110-1 to perform SL-only communication over the NR unlicensed network.

[0022] In one aspect, UE 110-1 can generate SL communications by sensing the SL channel with CCA and configuring a gap length based on the SCS, and can similarly generate a CPE length based on one or more conditions when acquiring the SL channel. For example, the gap length can comprise up to two gap symbols (or two OFDM symbols) when configuring SL communications using a 60 kHz SCS and only one gap symbol for other SCSs (e.g., 15 kHz or 30 kHz SCSs). Additionally or alternatively, a gap length of gap symbols (or guard symbols) can act as a placeholder in a slot transmission with up to two consecutive gap symbols before a physical PSFCH feedback channel (SL) transmission, at the end of the slot, or both before a PSFCH transmission and at the end of the slot, as shown by gap symbols 122A and 122B in FIG. 1. Before a PSFCH transmission can mean, for example, immediately before PSFCH symbol(s) 124 in slot 104. The gap symbols may be adjacent to each other, adjacent to the PSFCH symbol 124, or may be contiguous after the PSFCH symbol 124, for example, if there is a gap symbol 122B at the end of the slot 104.

[0023] Configuring up to two gap or double gap symbols in a slot with 60 kHz SCS can work as a solution for 60 kHz SCS or other specific configurations where the symbol duration is less than the Type 2A CCA sensing time or the Type 1 CCA deferral duration. Therefore, enabling and configuring up to two gap or OFDM symbols for the guard period or gap can ensure adequate time for CCA completion when COT sharing or non-COT sharing in SL.

[0024] In particular, for example, when utilizing 60 kHz SCS for SL-U, the symbol duration including the cyclic prefix is ​​17.84 microseconds, which is shorter than the 25 microsecond Type 2A CCA duration. In addition, the deferral duration of Type 1 CCA can be 25 microseconds or more (e.g., 34 microseconds) depending on the instruction associated with the channel access priority class (CAPC) p. Therefore, a single gap symbol length may not be sufficient without configuring the gap length to be a maximum of two symbols (gap or OFDM symbols), especially given that Type 1 CCA can be variable length before the slot transmission start time.

[0025] For example, the number of consecutive slot durations (m_p or m p ) may be equal to or set to 1 to indicate 25 microseconds, or equal to or set to 2 to indicate 34 microseconds, which may or may not be associated with CAPC. The deferral duration Td may consist of duration Tf = 16 microseconds immediately followed by m_p consecutive slot durations, each slot duration being Tsl = 9 microseconds, with Tf including an idle slot duration Tsl at the start of Tf. m_p may be equal to 1 if CAPC is 1, or equal to 2 if CAPC is 2, for transmission. Thus, a gap symbol length of two or more symbols can ensure sufficient time for CCA for each scenario. Table 4.2.1-1 of TS 37.213 Release 17 shows CAPC for the UL as an example of CAPC and Mp slot durations, which is incorporated herein by reference below.

[0026] [Table 1]

[0027] In one aspect, a gap length of up to two gap symbols can be configured at the end of a slot for 60 kHz SCS. This can be configured for each slot transmission or in multi-slots for transmissions using a partial bandwidth (BW) of a resource block (RB) set, where the full BW can be, for example, the entire RB set with a 20 MHz component carrier (CC) bandwidth. In single-slot transmissions, configuring a gap length of up to two gap symbols within a slot can allow CCA to be fully or successfully performed immediately before SL transmission when 60 kHz SCS is employed. When COT sharing is active or utilized, the sensing length is approximately 25 microseconds. In the case of non-COT sharing, or in the absence of SL COT sharing communication, a gap can allow successful sensing before SL transmission after terminating Type 1 CCA before the slot start time. Due to the shorter OFDM symbol line with 60 kHz SCS, additional gap symbols can be generated during CCA calculations to accommodate the slot configuration accordingly. However, the 15 and 30 kHz SCSs can reuse legacy configurations in SL. Generally, SL for Frequency Range 1 (FR1) includes SCS support for 15 kHz, 30 kHz, and 60 kHz SCSs, although other frequency ranges and SCSs may also be utilized in various aspects throughout this disclosure.

[0028] In another aspect, a CPE is used in an unlicensed band for both licensed assisted access (LAA) or NR-U and operates to fill a transmission gap after contention operations (e.g., CCA) end and before SL transmission begins. CCA for SL transmission can utilize a 9 microsecond slotted CCA time, for example, coming from Wi-Fi or an unlicensed band, which are asynchronous transmissions. Once CCA ends, the UE can begin transmission. However, 3GPP systems may be synchronous transmissions, and therefore SL transmissions start within a minimum of a symbol boundary, resulting in a small time gap to be filled, which is a function of the cyclic prefix (CP) extension (CPE, or extended cyclic prefix (ECP)) that has some information to withhold transmission for alignment purposes.

[0029] In particular, the CPE may transmit from a CPE start position prior to the SL transmission according to various aspects. In one example, the CPE may be within the symbol or symbol position / length immediately preceding the next AGC symbol. Alternatively or additionally, the CPE may be based on the SCS. For example, the CPE may be within the symbol or symbol position / length immediately preceding the next AGC symbol for a 15 kHz SCS, and within at most or at most two symbols (or symbol positions / lengths) immediately preceding the next AGC symbol for a 30 or 60 kHz SCS.

[0030] 2 illustrates an example of an SL slot for SL communication 200 in an NR unlicensed network between an initiating UE 110-1 and a receiving UE 110-2. Here, the structure / configuration of the SL slot 204 is similar to the SL slot 104 of FIG. 1, but does not include a PSFCH symbol or an ACK / NACK channel, and has only one gap symbol or set of gap symbols 222. A single gap length can be configured at the end of the slot 204. The SL slot 204 includes symbols that each include a resource block spanning the vertical axis of each subchannel 202. The symbols of the slot 204 also include an AGC symbol 216, a PSCCH symbol 218, a PSSCH symbol 220, and a gap symbol 222 having a gap length of up to two gap symbols at the end of the slot 204 of FIG. 2.

[0031] In single-slot transmission, configuring a gap length of up to two gap symbols 222 at the end of the slot can allow CCA to be fully performed immediately before SL transmission using a 60 kHz SCS. When COT sharing is active or utilized, the sensing length is approximately 25 microseconds if Type 2A sensing is utilized. In the case of non-COT sharing, or if there is no SL COT sharing communication, the gap can allow successful sensing before SL transmission after completing Type 1 CCA before the slot start time. COT sharing can be utilized when the initiating UE 110-1 performs Type 1 CCA, and COT resources can be shared with the responding UE 110-2 when the initiating UE does not use all COT resources in accessing the SL channel. The responding UE then only needs to perform one-shot CCA to obtain a shared COT in SL. Therefore, a gap length of up to two gap symbols 222 at the end of the slot can ensure that CCA is fully and properly performed for the 60 kHz SCS.

[0032] Figures 3 and 4 show examples of multi-SL slot transmission for SL-U communication 200. Figure 3 shows slots 302 and 304 as a multi-slot SL communication structure 300 utilizing a partial BW of RB set transmission, and Figure 4 shows slots 402 and 404 of a multi-slot communication structure 400 utilizing the full BW of RB set transmission.

[0033] 3 includes an AGC symbol 316, a PSCCH 318 symbol, a set of PSSCH symbols 320, and a gap symbol or set of gap symbols having a gap length 322. Slot 304 includes an AGC symbol 316', a PSCCH 318', a PSSCH 320', a first gap length having gap symbols 322A, a PSFCH 324', and a second gap length having gap symbols 322B. The gap symbols 322, 322A, and 322B may be up to two gap symbols long for a 60 kHz SCS and may be less than two symbols long (e.g., one symbol) long for other SCSs.

[0034] If multiple slots (e.g., slots 302, 304, or additional slots) comprise SL communication 300, the end of each slot can include a gap length of up to two gap symbols when partial BW transmission of an RB set is utilized. Thus, each slot of SL transmission, regardless of the SCS utilized for 15 kHz SCS, 30 kHz SCS, or 60 kHz SCS, etc., can be configured with at least one gap symbol at the end portion of the slot symbol when utilizing partial BW for multi-slot SL communication.

[0035] Alternatively or additionally, whether each slot in a multi-slot SL transmission configures a gap length at the end of each slot can be based on an instruction from the SCI for dynamic configuration. However, if the SCI does not provide an instruction on whether to configure a gap length (e.g., up to two gap symbols) at the end of each slot in a multi-slot SL transmission, the default configuration for the partial BW of the RB set can be to enable gap symbol(s) at the end of each slot (e.g., slots 302 and 304) of the multi-slot SL transmission. Alternatively, the default configuration for the partial BW can be to configure a gap length (e.g., up to two gap symbols) only at the end of the last slot (e.g., slot 304 with gap symbol 222B).

[0036] These aspects of Figure 3 can be applied to a 60 kHz SCS, as well as to other SCSs (e.g., a 15 kHz SCS, a 30 kHz SCS, or other SCSs) as well as 60 kHz. For example, a 60 kHz SCS can configure the gap length to be a maximum of two symbols, but other SCSs (e.g., a 15 kHz SCS, a 30 kHz SCS, or other SCSs) can also configure the gap length at the end of each slot in a multi-slot SL transmission, either as a default configuration or based on an SCI instruction of whether to dynamically configure each slot with a gap length at the end of the slot. If indicated or configured by an SCI instruction, the SCI can determine the configuration of the gap length at the end of each slot or only at the last slot of a multi-slot SL transmission based on the SCI instruction.

[0037] Additionally or alternatively, other gap configurations can be configured within each slot 302 or 304, respectively. For example, up to two gap symbols for 60 kHz and one gap length for other SCSs can be created before each PSFCH (e.g., PSFCH 324'). While slot 302 in this example does not have a PSFCH, slot 304 is configured with a gap length of, for example, one gap symbol(s) 322A before PSFCH 324'.

[0038] FIG. 4 shows another example of slots 402 and 402 in a multi-slot SL transmission. However, each slot in the multi-slot SL transmission 400 does not have a gap length at the end. Slot 402 includes an AGC symbol 416, a PSCCH 418 symbol, and a set of PSSCH symbols 420 without a gap symbol or set of gap symbols at the end of the symbol. Slot 404 is similar to slot 304 of FIG. 3 and includes an AGC symbol 416′, a PSCCH 418′, a PSSCH 420′, a first gap length 422A with gap symbols, a PSFCH 424′, and a second gap length 422B with gap symbols. Gap symbols 422A and 422B may be up to two gap symbols long, for example, for a 60 kHz SCS, and less than two symbols long (e.g., one symbol) long for other SCSs.

[0039] If multiple slots (e.g., slots 402, 404, or additional slots) include SL communication or multi-slot SL transmission, the default configuration may include a gap length of up to two symbols at the end of only the last slot 404 for all SCSs when the entire BW of the RB set is utilized. This may enable continuous transmission without additional CCA when multi-slot SL communication is configured using the entire BW, entire BW, or complete BW of the RB set. Thus, a UE (e.g., initiating UE 110-1) may generate one slot with at least one gap symbol at the end of the slot symbol when utilizing the entire BW for SL communication. This slot may be, for example, the last slot in a multi-slot SL transmission. Similar to FIG. 3, the gap length of the gap symbol(s) may be configured immediately before the PSFCH 424′ or any other location within the slot (e.g., slot 404) where the PSFCH is generated. When the SCS of a multi-slot SL transmission is a 60 kHz SCS, the gap symbol or gap length can include up to two gap symbols and fewer than two symbols for other SCSs of other SL transmissions. The gap symbol can be, for example, one symbol for a 15 kHz SCS or a 30 kHz SCS, and the gap symbol is primarily for Tx / Rx switching after a PSSCH transmission. However, in the case of unlicensed communication (e.g., SL-U), the gap symbol is also configured to not only perform Tx / Rx switching but also perform CCA within the gap symbol / gap length, and the CCA can have a certain length specified by the 3GPP standard or regulations.

[0040] 5, an example of SL channel transmission(s) 500 that may be used in conjunction with determining a CPE length in accordance with various aspects of the present disclosure is shown. The UE may generate SL communications by configuring a gap length based on the SCS, as well as determine the CPE, including the CPE length, based on one or more conditions when acquiring the SL channel.

[0041] Depending on the COT sharing, the PSSCH symbol 502 may be followed by a 25 microsecond gap 504 associated with the CPE 506 of the PSFCH symbol 508. This may be followed by another 25 microsecond gap 510 of the AGC symbol 514 and the CPE 512. The CPE length of the CPE 506 or 512 may be configured based on a pre-configured CPE length in a resource pool. In one aspect, the CPE length of a CPE (e.g., CPE 506) may be a default CPE length pre-configured by the resource pool according to one or more conditions. For example, when the CPE is used in a shared COT or when COT sharing is performed on an SL channel using at least one of a PSCCH, PSSCH, or PSFCH transmission, the CPE length may be the default CPE length. In other words, one or more of the PSCCH, PSSCH, or PSFCH may utilize a default CPE length based on the SL resource pool when COT sharing is performed. Here, a 25 microsecond gap 504 is configured for COT sharing, with the CPE 506 or 512 referencing the last symbol of the previous slot. Alternatively, for example, if COT sharing is occurring along with a PSCCH transmission, the first symbol 502 may be followed by a similar structure of a 25 microsecond gap 504, providing for the CPE to fill the remainder of the gap for a PSFCH symbol or for CCA.

[0042] Alternatively or additionally, the CPE length may be a default CPE length preconfigured by a resource pool with only PSFCH when the PSFCH transmission is outside the shared COT (or part of the starting COT transmission), which means that the SL transmission of the PSFCH does not have a previous PSSCH transmission or receive any COT sharing information to share the COT, and therefore the UE performs Type 1 CCA before the SL transmission.

[0043] Alternatively or additionally, the CPE length may be a default CPE length preconfigured by the resource pool with at least one of the PSCCH or PSSCH outside the shared COT (a portion of the initiated COT transmission), or when the complete or entire RB set (20 MHz) utilizes a partial BW of the RB set that is not utilized for SL transmission. Therefore, two conditions for utilizing the default CPE length preconfigured by the resource pool for SL may be that the PSCCH / PSSCH transmission involves a partial BW and is outside the shared COT (UE initiated COT). Outside the shared COT may mean that the transmission is in its own initiated COT. A partial BW means that the transmission is a portion or subset of the RB set that includes the 20 MHz CC bandwidth. If the UE is using only a portion of it (e.g., one or two subchannels), this means that the data transmission is frequency division multiplexed (FDMed) with other data transmissions. Depending on these two conditions "partial BW" and "outside shared COT" being met, the combined transmission will use the default CPE length with a fixed gap.

[0044] In another aspect, the CPE may be configured with a default value based on the SCS. For a 15 kHz or 30 kHz SCS, the default CPE length may be, for example, one OFDM symbol minus 25 microseconds. The default CPE length may be RRC configured rather than based on a pre-configured resource pool. For a 60 kHz SCS, a gap length of two OFDM symbols minus 25 microseconds may be used, giving a CPE length of 10.7 microseconds. Thus, the CPE length of CPE 506 or 512 may be a value dependent on the SCS. One gap symbol or two gap symbols may be intended to be a 25 microsecond gap with the remaining time filled with the CPE length.

[0045] 6 shows another example of SL channel transmission(s) 600 that may be used in conjunction with determining the CPE length based on a pre-configured CPE length of a resource pool or RRC signaling, as described above. Here, the start of the transmission is a PSCCH or PSSCH transmission 602, followed by a 25 microsecond gap 604 and an extended CP or CPE 606 for AGC symbols 608. If COT sharing is occurring for a data transmission (e.g., a PSSCH transmission), the CPE 606 fills the last gap symbol of the previous slot, and the CPE length may be RRC specified or according to a pre-configuration of the resource pool.

[0046] As explained above, the CPE length may alternatively be configured based on the SCS. In one aspect, the default CPE length may be one OFDM symbol length minus a 25 microsecond gap in 15 kHz and 30 kHz SCSs. For example, for 15 kHz, one OFDM symbol may be 71.4 microseconds, so 71.4 minus 25 microseconds equals a default CPE length of 46.4 microseconds (us). In a 30 kHz SCS, one OFDM symbol may be 35.7 us, so 35.7 us minus 25 us equals a default CPE length of 10.7 us. In a 60 kHz SCS with two OFDM symbol lengths, the default CPE length may be 35.7 us minus 25 us, which equals 10.7 us.

[0047] 7 shows examples of dynamic signaling 700, 710, and 720 in an SCI with a shared COT to indicate CPE length and CCA type. The configured CPE length and CCA type signaled by the SCI may apply to one or more of the PSCCH / PSSCH / PSFCH that share the COT.

[0048] In some implementations, when a Type 2 CCA is signaled to create a 25 us gap 704, a 16 us gap 714, or a gap less than 16 us 724 between shared COT SL communications, a CP extension or a CPE may be implemented (e.g., upon receiving a signal from UE 110-1, UE 110-2 may implement a CP extension to create a prescribed gap between shared COT SL communications). In some implementations, when a Type 1 CCA is signaled, a CP extension may be used. In such scenarios, the CP extension may not be enabled for partial BW scenarios (e.g., a scenario in which the CG from base station 922 in FIG. 9 involves a partial BW). In contrast, the CP extension may be enabled for full BW scenarios (e.g., a scenario in which the CG from base station 922 involves a full BW).

[0049] In addition to the static configuration described in the previous figures, dynamic updates or changes to the CPE length and CCA type can be configured based on the SCI information transmitted on the PSCCH or PSSCH 702, 712, 722 depending on whether it is in Phase 1 or Phase 2. When COT sharing information, the CPE length and CCA type can be part of the SCI Phase 1 or Phase 2 SCI. When indicated via SCI, the UE can dynamically override the previous RRC configuration with the next RRC configuration indicated in the most recent SCI received. As a result, the CPE length and CCA type can be applied to one or more of the PSCCH / PSSCH / PSFCH, for example, along with all shared channels for a shared COT.

[0050] In one aspect, 2-bit signaling may be configured to signal, for example, a combination of CCA type and CPE. For CCA Type 2A, the CPE is the difference between one OFDM symbol (or two for 60 kHz SCS) long and 25 us. Type 2A CCA is 25 microseconds in duration, and the CPE length is for CCA Type 2A, the CPE 706 is one (or two for 60 kHz SCS) OFDM symbol length minus 25 us. For CCA Type 2B, the CPE 716 is one (or two for 60 kHz SCS) OFDM symbol length minus 16 us in signaling 710. Since the CCA time is 16 microseconds, the CPE 716 is one symbol minus the gap 714. CCA Type 2C is less than 16 microseconds, so there is no longer any need to perform CCA, and it is time for the CPE 716 to fill the remainder of the gap. For CCA Type 2C, the CPE 726 is greater than one (or two for 60 kHz SCS) OFDM symbol length minus 16 microseconds. AGC symbols 708, 718, and 728 may follow each CPE 706, 716, and 726, respectively.

[0051] Therefore, each CPE length may depend on the gap length. If the gap symbol is much longer than another CCA length, the CPE may be utilized to extend the CCA to fill the gap for reservation purposes.

[0052] If the SCI does not include CCA type or CPE length information, a default value or length can be used. In the case of partial BW COT, if multiple UEs are starting COT, dynamic signaling may cause some misalignment with the starting symbol, and therefore dynamic triggering may only be applied to the full BW COT, but not necessarily. SCI signaling may be optional. If present, the SCI may override the previous RRC configuration of the CPE length; otherwise, the UE may use the previous or current RRC configuration.

[0053] Additionally or alternatively, multiple CPEs may be used with full BW transmission for UE-initiated COT (in other words, when the transmission is outside the shared COT). In that case, multiple CPEs may be within one or two symbols. In the case of multiple CPEs, the starting position of the CPE may be randomly selected based on the 9 microsecond sensing slot boundary. For 15 kHz SCS, the CPE may be one symbol, then two OFDM symbols for 30 kHz and 60 kHz. Thus, the starting position may be randomly selected from the sensing slot (9 us) boundary with one (15 kHz SCS) or two OFDM (30 kHz and 60 kHz) symbols.

[0054] 8 shows an example process flow 800 for configuring SL-U gap symbols and CPE length for SL communication. Process flow 800 can begin at 810 with generating the SL communication by sensing the SL channel using CCA and configuring the gap length based on the SCS and the CPE with the CPE length. At 820, the process flow includes transmitting the SL communication in response to acquiring the SL channel.

[0055] In an aspect, process flow 800 may further include generating each slot having at least one gap symbol at the end of the slot symbol when using a partial BW for SL communication or based on the SCI configuration. Additionally or alternatively, when using the entire BW for SL communication, one slot may be generated having at least one gap symbol at the end of the slot symbol. In response to the SCS for SL communication including a 60 kHz SCS, the at least one gap symbol may include up to two symbols, and the gap symbol length for other SCSs (e.g., 15 or 30 kHz SCSs) may be, for example, one symbol.

[0056] 9 is an example network 900 according to one or more implementations described herein. The example network 900 may include UEs 110-1, 110-2, etc. (collectively referred to as “UEs 110” and individually referred to as “UEs 110”), a radio access network (RAN) 920, a core network (CN) 930, an application server 940, and an external network 950.

[0057] The UE 110 can communicate with and establish (communicatively couple to) a connection with the RAN 920, which can include one or more wireless channels 914-1 and 914-2, each of which can comprise a physical communication interface / layer. In some implementations, the UE can be configured with dual connectivity (DC) as multi-radio access technology (multi-RAT) or multi-radio dual connectivity (MR-DC), where multiple receive and transmit (Rx / Tx) capable UEs can use resources provided by different network nodes or base stations 922 (e.g., 922-1 and 922-2), which can be connected via a non-ideal backhaul (e.g., one network node provides NR access and the other network node provides either E-UTRA for LTE or NR access for 5G). In such a scenario, one network node can operate as a master node (MN) and the other can function as a secondary node (SN). The MN and SN can be connected via a network interface, and at least the MN can be connected to the CN 930. Additionally, at least one of the MN or SN can operate using shared spectrum channel access, and functionality designated for the UE 110 can be used for integrated access and backhaul mobile termination (IAB-MT). Similar to the UE 110, the IAB-MT can access the network using either one network node or two different nodes using an enhanced dual connectivity (EN-DC) architecture, a new radio dual connectivity (NR-DC) architecture, or other direct connectivity such as an SL communication channel as the SL interface 912.

[0058] In some implementations, a base station (as described herein) may be an example of a network node 922. As shown, the UE 110 may additionally or alternatively connect to an access point (AP) 916 via an interface 918, which may include an air interface that allows the UE 110 to communicatively couple with the AP. The AP 916 may comprise a wireless local area network (WLAN), a WLAN node, a WLAN termination point, etc. The connection 918 may comprise a local wireless connection, such as a connection conforming to any IEEE 702.11 protocol, and the AP 916 may comprise a Wireless Fidelity (Wi-Fi) router or another AP. The AP 916 may also be connected to another network (e.g., the Internet) without connecting to the RAN 920 or the CN 930.

[0059] The RAN 920 may also include one or more RAN nodes 922-1 and 922-2 (collectively referred to as RAN nodes 922 and individually referred to as RAN node 922) that enable channels 914-1 and 914-2 to be established between the UE 110 and the RAN 920. The RAN nodes 922 may include network access points configured to provide wireless baseband functionality for data or voice connectivity between a user and a network based on one or more of the communication technologies described herein (e.g., 2G, 3G, 4G, 5G, WiFi, etc.). Thus, by way of example, the RAN node may be an E-UTRAN Node B (e.g., an enhanced Node B, eNodeB, eNB, 4G base station, etc.), a next-generation base station (e.g., a 5G base station, an NR base station, a next-generation eNB (gNB), etc.). The RAN node 922 may include a roadside unit (RSU), a transmit / receive point (TRxP or TRP), and one or more other types of ground stations (e.g., terrestrial access points). In some scenarios, the RAN node 922 may be a dedicated physical device, such as a macrocell base station or a low power (LP) base station, to provide a femtocell, picocell, etc., having a smaller coverage area, smaller user capacity, or higher bandwidth compared to a macrocell. As described below, in some implementations, a satellite may operate as a base station (e.g., a RAN node 922) to a UE 110. Thus, references herein to a base station, RAN node 922, etc., may include implementations in which the base station, RAN node 922, etc., is a terrestrial-based network node and implementations in which the base station, RAN node 922, etc., is a non-terrestrial-based network node.

[0060] Some or all of the RAN nodes 922 may be implemented as one or more software entities running on server computers as part of a virtual network, which may be referred to as a centralized RAN (CRAN) or a virtual baseband unit pool (vBBUP). In these implementations, the CRAN or vBBUP may implement RAN function splitting, such as a Radio Resource Control (RRC) and Packet Data Convergence Protocol (PDCP) splitting, where the Radio Resource Control (RRC) and Packet Data Convergence Protocol (PDCP) layers are operated by the CRAN / vBBUP and other Layer 2 (L2) protocol entities may be operated by individual RAN nodes 922; a MAC / PHY layer splitting, where the RRC, PDCP, Radio Link Control (RLC), and Media Access Control (MAC) layers are operated by the CRAN / vBBUP and the Physical (PHY) layer may be operated by individual RAN nodes 922; or a "lower PHY" splitting, where the RRC, PDCP, RLC, MAC, and upper portions of the PHY layer are operated by the CRAN / vBBUP and lower portions of the PHY layer may be operated by individual RAN nodes 922. This virtualized framework may enable freed processor cores of the RAN nodes 922 to run other virtualized applications, for example.

[0061] In some implementations, individual RAN nodes 922 can represent individual gNB distributed units (DUs) connected to a gNB control unit (CU) via an individual F1 interface. In such implementations, the gNB-DUs can include one or more remote radio heads or radio frequency (RF) front end modules (RFEMs), and the gNB-CUs can be operated by a server (not shown) located in the RAN 920 or by a server pool (e.g., a group of servers configured to share resources) in a manner similar to a CRAN / vBBUP. Additionally or alternatively, one or more of the RAN nodes 922 can be next-generation eNBs (i.e., gNBs), which can provide Evolved Universal Terrestrial Radio Access (E-UTRA) user plane and control plane protocol terminations for the UEs 110 and can be connected to a 5G core network (5GC) 930 via a next-generation (NG) interface 924.

[0062] Any of the RAN nodes 922 can terminate air interface protocols and can be the first point of contact for the UE 110. In some implementations, any of the RAN nodes 922 can perform various logical functions for the RAN 920, including radio network controller (RNC) functions such as, but not limited to, radio bearer management, uplink and downlink dynamic radio resource management and data packet scheduling, and mobility management. The UEs 110 can be configured to communicate with each other or any of the RAN nodes 922 using Orthogonal Frequency-Division Multiplexing (OFDM) communication signals over multi-carrier communication channels according to various communication technologies, including, but not limited to, OFDMA communication technologies (e.g., for downlink communication) or Single Carrier Frequency-Division Multiple Access (SC-FDMA) communication technologies (e.g., for uplink and ProSe or SL communication), although the scope of such implementations is not necessarily limited in this respect. An OFDM signal can include multiple orthogonal subcarriers.

[0063] A physical downlink shared channel (PDSCH) may carry user data and higher layer signaling to the UEs 110. A physical downlink control channel (PDCCH) may carry, among other things, information regarding the transport format and resource allocation for the PDSCH channel. The PDCCH may also inform the UEs 110 about the transport format, resource allocation, and hybrid automatic repeat request (HARQ) information for the uplink shared channel. Typically, downlink scheduling (e.g., allocating control and shared channel resource blocks to the UEs 110-2 in a cell) may be performed by any of the RAN nodes 922 based on channel quality information fed back from any of the UEs 110. Downlink resource allocation information may be transmitted on the PDCCH used (e.g., allocated) for each of the UEs 110.

[0064] The PDCCH carries control information using control channel elements (CCEs), and the number of CCEs (e.g., six or other numbers) can be organized into resource element groups (REGs), where a REG is defined as a physical resource block (PRB) within an OFDM symbol. Before being mapped to resource elements, the PDCCH complex-valued symbols may first be organized into quadruplets, for example, and then shuffled using a sub-block interleaver for rate matching. Each PDCCH may be transmitted using one or more of these CCEs, and each CCE may correspond to nine sets of four physical resource elements known as REGs. Four quadrature phase shift keying (QPSK) symbols may be mapped to each REG. The PDCCH can be transmitted using one or more CCEs depending on the size of the DCI and the channel conditions. There may be four or more different PDCCH formats with different numbers of CCEs (e.g., aggregation levels, L=1, 2, 4, 8, or 16).

[0065] The RAN nodes 922 may be configured to communicate with each other via an interface 923. In an implementation where the system is an LTE system, the interface 923 may be an X2 interface. In an LTE network, the X2 and S1 interfaces are defined as interfaces between RAN nodes and between the RAN and the core network. 5G can operate in two modes: non-standalone mode and standalone mode. For non-standalone operation, this specification defines extensions of the S1 and X2 interfaces as X2 / Xn for interfaces between RAN nodes 922 and S1 / NG for interface 924 between the RAN 920 and the CN 930, as in the standalone operation. The interface 924 may be defined between two or more RAN nodes 922 (e.g., two or more eNBs) connecting to an evolved packet core (EPC) or the CN 930, and / or between eNBs connecting to the EPC. In some implementations, the X2 / Xn interface may include an X2 / Xn user plane interface (X2-U / Xn-U) and an X2 control plane interface (X2-C / Xn-C). The X2-U / Xn-U may provide a flow control mechanism for user data packets forwarded over the X2 / Xn interface and may be used to communicate information regarding the delivery of user data between eNBs or gNBs. For example, the X2-U / Xn-U may provide information regarding specific sequence numbers of user data forwarded from a master eNB (MeNB) to a secondary eNB (SeNB), information regarding successful sequence delivery of PDCP packet data units (PDUs) from the SeNB to the UE 110 for user data, information regarding PDCP PDUs that were not delivered to the UE 110, information regarding the current minimum desired buffer size at the SeNB for transmitting user data to the UE, etc.X2-C / Xn-C can provide intra-LTE access mobility functionality (e.g., including context transfer from source eNB to target eNB, user plane transport control, etc.), load management functionality, and inter-cell interference coordination functionality.

[0066] Alternatively or additionally, the RAN 920 may also be connected (e.g., communicatively coupled) to the CN 930 via a Next Generation (NG) interface as interface 924. The NG interface 924 may be divided into two parts: a Next Generation (NG) user plane (NG-U) interface 926, which carries traffic data between the RAN node 922 and a User Plane Function (UPF), and an S1 Control Plane (NG-C) interface 928, which is a signaling interface between the RAN node 922 and an Access and Mobility Management Function (AMF).

[0067] The CN 930 may comprise multiple network elements 932 configured to provide various data and telecommunication services to customers / subscribers (e.g., users of UEs 110) connected to the CN 930 via the RAN 920. In some implementations, the CN 930 may include an Evolved Packet Core (EPC), a 5G CN, and / or one or more additional or alternative types of CN. The components of the CN 930 may be implemented in a single physical node or separate physical nodes, including components for reading and executing instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium).

[0068] As shown, the CN 930, the application server 940, and the external network 950 can be connected to each other via interfaces 934, 936, and 938, which can include IP network interfaces. The application server 940 can include one or more server devices or network elements (e.g., a virtual network function (VNF) that provides applications using IP bearer resources (e.g., a Universal Mobile Telecommunications System Packet Service (UMTS PS) domain, an LTE PS data service, etc.) in conjunction with the CN 930). The application server 940 can also, or alternatively, be configured to support one or more communication services (e.g., voice over IP (VoIP sessions, push-to-talk (PTT) sessions, group communication sessions, social networking services, etc.)) for the UE 110 via the CN 930. Similarly, the external network 950 can include one or more of a variety of networks, including the Internet, thereby providing the mobile communication network and the UE 110 of the network with access to various additional services, information, interconnectivity, and other network functions.

[0069] In one aspect, UEs 110-1 and 110-2 can operate as initiator and receiver UEs, respectively, in SL communication over the SL channel. UE 110-1 can generate the SL communication by, for example, sensing the SL channel using CCA and configuring a gap length based on an SCS and a CPE length. The UE can then transmit the SL communication in response to acquiring the SL channel. The CPE length can be based on the gap length and SCS utilized for the SL communication. The UE can dynamically generate a CCA type for the CPE and CCA with the CPE length based on at least one of the SCI or SCS for the shared COT. UE 110-1 is configured to process, execute, generate, communicate, or cause to be performed any one or more combined further aspects described herein or associated with any of FIGS. 1 through 8.

[0070] 10 , a block diagram of a UE device 110 (e.g., UE 110-1 or 110-2) or other network component / device 1000 (e.g., V-UE / P-UE, IoT, gNB, eNB, base station, or other participating network entity / component) is shown. The device 1000 includes one or more processors 1010 (e.g., one or more baseband processors) with processing circuitry and associated interface(s), transceiver circuitry 1020 (e.g., with RF circuitry that may include transmitter circuitry (e.g., associated with one or more transmit chains) and / or receiver circuitry (e.g., associated with one or more receive chains), which may use common circuit elements, separate circuit elements, or a combination thereof), and memory 1030 (which may include any of a variety of storage media and may store instructions and / or data associated with one or more of the processor(s) 1010 or transceiver circuitry 1020).

[0071] The memory 1030 (as well as other memory components described herein, e.g., memory, data storage, etc.) may include one or more machine-readable medium(s) containing instructions that, when executed by a machine or component described herein, cause the machine or other device to perform operations of a method, apparatus, or system for communicating using multiple communication technologies in accordance with the aspects, embodiments, and examples described herein. It should be understood that the aspects described herein can be implemented by hardware, software, firmware, or any combination thereof. If implemented in software, the functions can be stored on or transmitted over a computer-readable medium (e.g., a memory or other storage device described herein) as one or more instructions or code. Computer-readable media includes both computer storage media and communication media, including any medium that facilitates transfer of a computer program from one place to another. Storage media or computer-readable storage devices may be any available medium that can be accessed by a general-purpose computer or a special-purpose computer. By way of example, and not limitation, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other tangible and / or non-transitory medium that can be used to hold or store desired information or executable instructions. Any connection may also be termed a computer-readable medium.

[0072] The memory 1030 may include executable instructions and may be integrated with or communicatively coupled to the processor or processing circuit 1010. The executable instructions in the memory 1030 may cause the processing circuit 1010 to generate an SL communication by sensing the SL channel with CCA, configuring a gap length based on the CPE with the SCS and CPE length, and transmitting the SL communication in response to acquiring the SL channel. The gap length may be configured with up to two consecutive gap symbols before the PSFCH, at the end of the slot, or before the PSFCH and at the end of the slot. Additionally or alternatively, sensing the SL channel may be performed with a sensing length of 25 microseconds using Type 2A CCA, depending on sharing the SL-U COT with the SL communication. The gap length may include two gap symbols with a 60 kHz SCS. Additionally or alternatively, sensing the SL channel may be performed with Type 1 CCA before transmitting the SL slot as a non-COT shared transmission, with the gap length of the SL slot comprising up to two gap symbols for the 60 kHz SCS. The CPE length may be configured based on a pre-configured CPE length in a resource pool associated with at least one of a physical sidelink control channel (PSCCH), a physical sidelink shared channel (PSSCH), or a PSFCH in a shared COT.

[0073] Device 1000 is configured to process, execute, generate, communicate, or cause to be performed any one or more combined aspects described herein or in connection with any of Figures 1 through 9.

[0074] Although the methods described within this disclosure are illustrated and described herein as a series of acts or events, it is understood that the illustrated order of such acts or events is not to be construed in a limiting sense. For example, some acts may occur in a different order and / or concurrently with other acts or events other than those illustrated and / or described herein. In addition, not all illustrated acts may be required to implement one or more aspects or embodiments of the description herein. Furthermore, one or more of the acts shown herein may be performed in one or more separate acts and / or phases. For ease of explanation, reference may be made to the above figures. However, these methods are not limited to any particular aspects or examples provided within this disclosure and may be applied to any of the systems / devices / components disclosed herein.

[0075] It is well understood that the use of personal information should comply with generally recognized privacy policies and practices that meet or exceed industry or government requirements for maintaining user privacy. In particular, personal information data should be managed and handled in a manner that minimizes the risk of unintended or unauthorized access or use, and the nature of authorized uses should be clearly indicated to users.

[0076] The present disclosure will be described with reference to the accompanying drawings, wherein like reference numerals are used to refer to like elements throughout, and wherein the structures and devices depicted are not necessarily drawn to scale. As used herein, terms such as “component,” “system,” and “interface” are intended to refer to computer-related entities, hardware, (e.g., executing) software, and / or firmware. For example, a component may be a processor (e.g., a microprocessor, controller, or other processing device), a process running on a processor, a controller, an object, an executable file, a program, a storage device, a computer, a tablet PC, and / or user equipment (e.g., a mobile phone) equipped with a processing device. Illustratively, an application running on a server and that server may also be a component. One or more components may reside within a process, and a component may be localized on one computer and / or distributed among two or more computers. This specification may describe a set of elements or other components, where the term “set” may be interpreted as “one or more.”

[0077] Further, these components may execute, e.g., as modules, from various computer-readable storage media having various data structures stored thereon. Components may communicate, for example, via local and / or remote processes, pursuant to signals comprising one or more data packets (e.g., data from a component interacting with another component via signals in a local system, a distributed system, and / or across a network, e.g., the Internet, a local area network, a wide area network, or a similar network with other systems).

[0078] As another example, a component may be a device having particular functionality provided by mechanical parts operated by electrical or electronic circuitry, where the electrical or electronic circuitry may be operated by software or firmware applications executed by one or more processors. The one or more processors may be internal or external to the device and may execute at least a portion of the software or firmware applications. As yet another example, a component may be a device that provides particular functionality through electronic components without mechanical parts, where the electronic components may comprise one or more processors that execute software and / or firmware that at least partially impart the functionality of the electronic components.

[0079] The use of the word "exemplary" is intended to make a concept concrete. The term "or" as used herein is intended to mean an inclusive "or," not an exclusive "or." That is, unless otherwise specified or clear from the context, "X uses A or B" is intended to mean any of all possible permutations. That is, "X uses A," "X uses B," or "X uses both A and B" all satisfy "X uses A or B." Additionally, the articles "a" and "an" as used in this application and the appended claims should generally be interpreted to mean "one or more" unless otherwise specified or clear from the context to refer to the singular form. Furthermore, when "including," "includes," "having," "has," "with," or variations thereof are used in either the detailed description or the claims, these terms are intended to be inclusive, similar to the term "comprising." Furthermore, in situations where one or more numbered items are recited (e.g., "first X," "second X," etc.), in some situations the context may indicate that one or more numbered items are separate or the same, but in general these one or more numbered items may be separate or the same.

[0080] As used herein, the term "circuitry" refers to, can be a part of, or can include an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group), or associated memory (shared, dedicated, or group) operably coupled to a circuit that executes one or more software or firmware programs, a combinatorial logic circuit, or other suitable hardware component that provides the described functionality. In some embodiments, a circuit may be implemented in, or functions associated with, one or more software or firmware modules may be performed by, one or more software or firmware modules. In some embodiments, a circuit may include logic operable at least partially in hardware.

[0081] As used herein, the term "processor" can refer to virtually any computing processing unit or device, including, but not limited to, a single-core processor, a single processor with software multithreading execution capabilities, a multi-core processor, a multi-core processor with software multithreading execution capabilities, a multi-core processor with hardware multithreading technology, a parallel platform, and a parallel platform with distributed shared memory. Furthermore, a processor can refer to an integrated circuit, an application-specific integrated circuit, a digital signal processor, a field programmable gate array, a programmable logic controller, a complex programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions and / or processes described herein. A processor can utilize nanoscale architectures, including, but not limited to, molecular dot and quantum dot-based transistors, switches, and gates, etc., to optimize space usage or improve mobile device performance. A processor can also be implemented as a combination of computing processing units.

[0082] Examples (embodiments) may include subject matter such as a method, means for performing an operation or block of a method, at least one machine-readable medium containing instructions that, when executed by a machine (e.g., a processor with memory, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), etc.), cause the machine to perform the operation of the method or the operation of an apparatus or system to perform simultaneous communications using multiple communication technologies according to the embodiments and examples described herein.

[0083] A first example is a user equipment (UE) comprising a processing circuit including at least one memory, the processing circuit being configured to cause the UE to sense an SL channel using clear channel assessment (CCA), generate a sidelink (SL) communication, and transmit the SL communication by configuring a gap length based on a subcarrier spacing (SCS) and a cyclic prefix extension (CPE) including a CPE length in response to acquiring the SL channel.

[0084] A second example may include the first example, where the gap length includes up to two gap symbols when configuring SL communication using 60 kHz SCS.

[0085] A third example may include the first or second example, where the gap length includes up to two consecutive gap symbols before a physical sidelink feedback channel (PSFCH) transmission, at the end of the slot, or before a PSFCH transmission and at the end of the slot.

[0086] A fourth example may include any one or more of the first through third examples, wherein the processing circuitry is further configured to perform sensing of the SL channel with a sensing length of 25 microseconds in response to sharing the SL unlicensed (SL-U) COT with the SL communication, and the gap length includes up to two gap symbols.

[0087] A fifth example may include any one or more of the first through fourth examples, wherein the processing circuitry is further configured to perform sensing of the SL channel using Type 1 CCA before transmitting the SL slot as a non-COT shared transmission, and wherein the gap length of the SL slot includes up to two gap symbols.

[0088] A sixth example may include any one or more of the first through fifth examples, wherein the processing circuitry is configured to generate each slot having at least one gap symbol at an end of the slot symbol when utilizing a partial bandwidth (BW) for SL communication or based on a sidelink control information (SCI) configuration, and to generate one slot having at least one gap symbol at an end of the slot symbol when utilizing the entire BW for SL communication, and further configured, in response to the SCS of the SL communication including a 60 kHz SCS, to include at least one gap symbol including up to two symbols.

[0089] A seventh example may include any one or more of the first through sixth examples, wherein the CPE length is configured based on a pre-configured CPE length in the resource pool, and wherein the processing circuitry is further configured to generate the CPE including a CPE length using only a PSFCH outside the shared COT, at least one of a PSCCH or a PSSCH outside the shared COT when utilizing a partial BW, or at least one of a physical sidelink control channel (PSCCH), a physical sidelink shared channel (PSSCH), or a PSFCH within the shared COT.

[0090] An eighth example may include any one or more of the first through seventh examples, wherein the CPE length is a default CPE length based on an orthogonal frequency division multiplexing (OFDM) symbol length minus 25 microseconds at 15 kHz SCS or 30 kHz SCS, and based on two OFDM symbol lengths minus 25 microseconds at 60 kHz SCS, for SL communications.

[0091] A ninth example may include any one or more of the first through eighth examples, wherein the processing circuitry is further configured to generate the SL communication by dynamically generating a CPE having a CPE length and a CCA type of the CCA based on the SCI indication for the shared COT.

[0092] A tenth example may include any one or more of the first through ninth examples, wherein the SCI indication includes 2-bit signaling, and wherein the CPE length includes 1 OFDM symbol length minus 25 microseconds for CCA Type 2A, 1 OFDM symbol length minus 16 microseconds for CCA Type 2B, or greater than 1 OFDM symbol length minus 16 microseconds for CCA Type 2C, and depending on whether a 60 kHz SCS is utilized, the CPE length includes 2 OFDM symbol lengths minus microseconds for CCA Type 2A, minus 16 microseconds for CCA Type 2B, or greater than 2 OFDM symbol lengths minus 16 microseconds for CCA Type 2C.

[0093] An eleventh example may include any one or more of the first through tenth examples, wherein the processing circuitry is further configured to generate SL communications with the plurality of CPEs to initiate a COT with full BW transmission by selecting a start position at a sensing slot boundary with one OFDM symbol for a 15 kHz SCS or two OFDM symbols for a 30 kHz SCS or a 60 kHz SCS.

[0094] A twelfth example is a method for a user equipment (UE) that includes generating a sidelink (SL) communication by sensing a sidelink (SL) channel using clear channel assessment (CCA) and configuring a gap length based on the CPE using a subcarrier spacing (SCS) and a cyclic prefix extension (CPE) length, and transmitting the SL communication in response to acquiring the SL channel.

[0095] A thirteenth example may include the twelfth example, and further includes generating each slot having at least one gap symbol at an end of the slot symbol when utilizing a partial bandwidth (BW) for SL communication or based on a sidelink control information (SCI) configuration, and generating one slot having at least one gap symbol at an end of the slot symbol when utilizing the entire BW for SL communication, wherein the at least one gap symbol includes up to two symbols in response to the SCS of the SL communication including a 60 kHz SCS.

[0096] A fourteenth example may include any one or more of the twelfth to thirteenth examples, and further including configuring the gap length with up to two consecutive gap symbols before the physical sidelink feedback channel (PSFCH), at the end of the slot, or before the PSFCH of the slot and at the end of the slot.

[0097] A fifteenth example may include any one or more of the twelfth to fourteenth examples, and further includes, in response to sharing of SL unlicensed (SL-U) COT with SL communications, performing SL channel sensing with a Type 2A CCA with a sensing length of 25 microseconds, where the gap length includes two gap symbols, or performing SL channel sensing using Type 1 CCA before transmitting the SL slot as an unlicensed COT shared transmission, where the gap length of the SL slot includes up to two gap symbols.

[0098] A sixteenth example may include any one or more of the twelfth to fifteenth examples, and further include configuring the CPE length based on a pre-configured CPE length in a resource pool associated with at least one of a physical sidelink control channel (PSCCH), a physical sidelink shared channel (PSSCH), or a PSFCH in the shared COT.

[0099] A seventeenth example may include any one or more of the twelfth to sixteenth examples, and further include generating the CPE length using only a PSFCH in the starting COT, or using at least one of a PSCCH or a PSSCH outside the shared COT when utilizing a partial BW, or using at least one of a physical sidelink control channel (PSCCH), a physical sidelink shared channel (PSSCH), or a PSFCH in the shared COT.

[0100] An eighteenth example is a baseband processor configured to sense a sidelink (SL) channel using clear channel assessment (CCA), generate an SL communication by configuring a gap length based on a subcarrier spacing (SCS) and a CPE having a cyclic prefix extension (CPE) length, and transmit the SL communication in response to acquiring the SL channel.

[0101] A nineteenth example may include the eighteenth example, wherein the CPE length is based on a gap length and a subcarrier spacing (SCS) utilized for SL communication.

[0102] A twentieth example may include any one or more of the eighteenth to nineteenth examples, and is further configured to generate the SL communication by dynamically generating a CPE having a CPE length and a CCA type of the CCA based on at least one of the SCI or SCS for the shared COT.

[0103] Furthermore, various aspects or features described herein may be implemented as a method, apparatus, or article of manufacture using standard programming and / or engineering techniques. The term "article of manufacture," as used herein, is intended to encompass a computer program accessible from any computer-readable device, carrier, or medium. For example, computer-readable media may include, but are not limited to, magnetic storage devices (e.g., hard disks, floppy disks, magnetic strips, etc.), optical disks (e.g., compact disks (CDs), digital versatile disks (DVDs), etc.), smart cards, and flash memory devices (e.g., EPROMs, cards, sticks, key drives, etc.). Furthermore, various storage media described herein may represent one or more devices and / or other machine-readable media for storing information. The term "machine-readable medium" may include, but is not limited to, wireless channels and various other media capable of storing, containing, and / or carrying instruction(s) and / or data. Furthermore, a computer program product may include a computer-readable medium having one or more instructions or code operable to cause a computer to perform the functions described herein.

[0104] Communication media includes computer-readable instructions, data structures, program modules, or other structured or unstructured data in a data signal such as a modulated data signal, e.g., carrier wave or other transport mechanism, and includes any information delivery or transport medium. A "modulated data signal" or signals refers to a signal that has one or more characteristics set or changed in such a manner as to encode information in one or more signals. By way of example, and not limitation, communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared and other wireless media.

[0105] An exemplary storage medium may be coupled to the processor such that the processor can read information from, and write information to, the storage medium. Alternatively, the storage medium may be integral to the processor. Further, in some aspects, the processor and the storage medium may reside in an ASIC. In addition, the ASIC may reside in a user terminal. Alternatively, the processor and the storage medium may reside as discrete components in a user terminal. Additionally, in some aspects, the processes and / or operations of a method or algorithm may reside as one or any combination of codes and / or instructions on a machine-readable medium and / or computer-readable medium, which may be incorporated into a computer program product.

[0106] In this regard, while the disclosed subject matter has been described in connection with various embodiments and corresponding drawings, it should be understood that, where applicable, other similar embodiments can be used to perform the same, similar, alternative, or substitute functions of the disclosed subject matter, or modifications and additions can be made without departing from the described embodiments. Accordingly, the disclosed subject matter should not be limited to any single aspect described herein, but rather should be construed according to the breadth and scope of the following appended claims.

[0107] In particular, with regard to the various functions performed by the above-described components (assemblies, devices, circuits, systems, etc.), the terms used to describe such components (including references to "means") are intended to correspond to any component or structure that performs the specified function of the described component (e.g., that is functionally equivalent), even if it is not structurally equivalent to the disclosed structure that performs that function in the exemplary implementations of the present disclosure shown herein. Furthermore, while a particular feature may be disclosed with respect to only one of several implementations, such feature can be combined with one or more other features of other implementations, as may be desirable or advantageous for any given or particular application.

Claims

1. A user equipment (UE), a radio frequency (RF) circuit; a processing circuit including a memory, the processing circuit executing instructions stored in the memory to cause the UE to: Gaining access to a sidelink (SL) channel based on clear channel assessment (CCA); For SL communications, configuring a cyclic prefix extension (CPE) or gap length in response to gaining access to the SL channel based on a subcarrier spacing (SCS); and a processing circuit configured to cause the SL communication to be transmitted via the RF circuitry based on at least one of the CPE length or the gap length.

2. The UE of claim 1 , wherein the gap length includes a maximum of two gap symbols when configuring the SL communication using a 60 kHz SCS.

3. 2. The UE of claim 1, wherein the gap length comprises up to two consecutive gap symbols before a Physical Sidelink Feedback Channel (PSFCH) transmission, at the end of a slot, or before the PSFCH transmission and at the end of the slot.

4. The processing circuitry may further include:

2. The UE of claim 1, configured to perform sensing of the SL channel with a sensing length of 25 microseconds in response to sharing a SL-unlicensed (SL-U) channel occupation time (COT) with the SL communication, the gap length including up to two gap symbols.

5. The processing circuitry may further include:

2. The UE of claim 1, configured to perform sensing of the SL channel using Type 1 CCA before transmitting the SL slot as a non-COT shared transmission, and a gap length of the SL slot includes up to two gap symbols.

6. The processing circuitry may further include: generating each slot having at least one gap symbol at an end of a slot symbol when utilizing a partial bandwidth (BW) for the SL communication or based on a sidelink control information (SCI) configuration; 2. The UE of claim 1, wherein when an entire BW is utilized for the SL communication, the UE is configured to generate one slot having at least one gap symbol at the end of a slot symbol, and wherein the at least one gap symbol includes a maximum of two symbols in response to the SCS of the SL communication including a 60 kHz SCS.

7. 2. The UE of claim 1, wherein the CPE length is configured based on a preconfigured CPE length in a resource pool, and the processing circuitry is further configured to generate, for the UE, a CPE including the CPE length using only a PSFCH outside a shared COT, at least one of a physical sidelink control channel (PSCCH) or a physical sidelink shared channel (PSSCH) outside the shared COT when utilizing a partial BW, or at least one of a PSCCH, a PSSCH, or a PSFCH within the shared COT.

8. 2. The UE of claim 1, wherein the CPE length is a default CPE length based on an Orthogonal Frequency Division Multiplexing (OFDM) symbol length minus 25 microseconds for 15 kHz SCS or 30 kHz SCS, and based on two OFDM symbol lengths minus 25 microseconds for 60 kHz SCS, for the SL communication.

9. The processing circuitry may further include:

2. The UE of claim 1, configured to generate the SL communication by dynamically generating a CPE having the CPE length and a CCA type of a CCA based on an SCI indication for a shared COT.

10. 10. The UE of claim 9, wherein the SCI indication comprises 2-bit signaling, and wherein, depending on whether a 15 kHz SCS or a 30 kHz SCS is employed, the CPE length comprises one OFDM symbol length minus 25 microseconds for CCA Type 2A, the CPE length comprises the one OFDM symbol length minus 16 microseconds for CCA Type 2B, or the CPE length is greater than one OFDM symbol length minus 16 microseconds for CCA Type 2C; and, depending on whether a 60 kHz SCS is employed, the CPE length comprises two OFDM symbol lengths minus 25 microseconds for CCA Type 2A, two OFDM symbols minus 16 microseconds for CCA Type 2B, or greater than two OFDM symbol lengths minus 16 microseconds for CCA Type 2C.

11. The processing circuitry may further include:

10. The UE of claim 1, configured to generate the SL communication with multiple CPEs to initiate COT with full BW transmission by selecting a start position at a sensing slot boundary with one OFDM symbol for a 15 kHz SCS or two OFDM symbols for a 30 kHz SCS or a 60 kHz SCS.

12. 1. A method for a user equipment (UE), comprising: generating, via a processing circuit, a sidelink (SL) communication by gaining access to the SL channel using clear channel assessment (CCA) and configuring a cyclic prefix extension (CPE) length or gap length based on a subcarrier spacing (SCS); transmitting, via radio frequency (RF) circuitry, the SL communication in response to gaining access to the SL channel based on at least one of the CPE length or the gap length; A method comprising:

13. generating each slot having at least one gap symbol at the end of the slot symbol when utilizing a partial bandwidth (BW) for the SL communication or based on a sidelink control information (SCI) configuration; generating a slot having at least one gap symbol at an end of the slot symbol when the entire BW is utilized for the SL communication; In response to the SCS of the SL communication including a 60 kHz SCS, the at least one gap symbol includes a maximum of two symbols. The method of claim 12.

14. configuring the gap length using up to two consecutive gap symbols before a Physical Sidelink Feedback Channel (PSFCH), at the end of a slot, or before the PSFCH of the slot and at the end of the slot; The method of claim 12 further comprising:

15. performing sensing of the SL channel with a Type 2A CCA with a sensing length of 25 microseconds in response to sharing a SL Unlicensed (SL-U) Channel Occupancy Time (COT) with the SL communication, the gap length comprising two gap symbols; or Before transmitting an SL slot as a non-COT shared transmission, sensing the SL channel is performed using Type 1 CCA, and the gap length of the SL slot includes at most two gap symbols; The method of claim 12 further comprising:

16. configuring the CPE length based on a pre-configured CPE length in a resource pool associated with at least one of a Physical Sidelink Control Channel (PSCCH), a Physical Sidelink Shared Channel (PSSCH), or a PSFCH in a shared COT; The method of claim 12 further comprising:

17. generating the CPE length using only a PSFCH in a starting COT, or using at least one of a PSCCH or a PSSCH outside a shared COT when utilizing a partial BW, or using at least one of a PSCCH, a PSSCH, or a PSFCH in the shared COT; The method of claim 12 further comprising:

18. 1. A baseband processor that, when executing instructions stored in a memory, Generating a sidelink (SL) communication by accessing a sidelink (SL) channel based on a clear channel assessment (CCA), and configuring a cyclic prefix extension (CPE) length or gap length of a CPE based on a subcarrier spacing (SCS), thereby generating the SL communication; and in response to acquiring the SL channel, providing the SL communication to an interface with radio frequency (RF) circuitry for transmission by the RF circuitry.

19. 20. The baseband processor of claim 18, wherein the CPE length is based on a gap length and an SCS utilized for the SL communication.

20. The operation is generating the SL communication by dynamically generating the CPE having the CPE length and a CCA type of CCA based on at least one of an SCI or an SCS for a shared channel occupancy time (COT); The baseband processor of claim 18 further comprising:

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