Method and user equipment for sidelink communication

Abstract

This invention discloses a user equipment and method for sidelink (SL) communication. The method performed by the user equipment (UE) includes: determining whether the UE is operating in local mode or interleaved mode for SL communication; and in response to determining that the UE is operating in interleaved mode, decoding a first-stage SL control information (SCI) of an entity SL control channel (PSCCH) based on an interleaved mapping scheme, decoding a second-stage SCI of the PSSCH based on the decoded first-stage SCI, and decoding the PSSCH based on the decoded first-stage SCI and second-stage SCI.

Description

Technical Field

[0001] The present invention generally relates to sidelink (SL) communication on an unlicensed band. More specifically, the present invention relates to improving SL communication on an unlicensed band by utilizing a frequency interleaving design. Prior Art

[0002] Starting from Release 16, with limited or no transmission via an infrastructure node (e.g., a next-generation Node B), the 3rd Generation Partnership Project (3GPP) has standardized SL communication, which allows user equipments (UEs) to communicate directly with each other.

[0003] Up to Release 17, the 3GPP SL specifications have focused on vehicle-to-vehicle (V2V) on the public safety and intelligent transport system (ITS) bands. However, with the development of interactive services such as interactive games and data sharing between various terminals such as mobile phones, virtual reality (VR) / augmented reality (AR) devices, and robots, many of these interactive services are local in nature and benefit from the integration of cellular communication and SL communication.

[0004] FIG. 1 shows an example of a control path and a data path of a network controlled interactive service (NCIS). More specifically, Configuration A in FIG. 1 shows a control path and a data path using the same frequency, and Configuration B in FIG. 1 shows a control path and a data path using different frequencies.

[0005] Referring to FIG. 1, the data path and the control path can be deployed on a cellular link (Uu link) or on an SL (PC5 link). Most of the control plane is transmitted via the network, while most of the data and some control information are transmitted on the SL.

[0006] The unlicensed bands in the 5 / 6 GHz band and 60 GHz band can provide a large amount of additional bandwidth and flexibility to SL data transmission. Therefore, it is expected that in Release 18, 3GPP will standardize SL communication in the unlicensed band. However, in order to provide proximity services (ProSe) in the unlicensed band, various regulatory requirements need to be met.

[0007] For transmissions in the unlicensed band, regulatory requirements mandate that the UE occupies a substantial fraction of the channel in the frequency domain to meet the power spectral density (PSD) and occupied channel bandwidth (OCB) constraints.

[0008] More specifically, operations in the unlicensed spectrum are subject to power limits in all regions and bands in terms of equivalent isotropically radiated power (EIRP) and PSD to constrain the resulting radio access technology (RAT) and intra-RAT interference levels. For example, according to the rules of the European Telecommunications Standards Institute (ETSI), in the 5 GHz band, the maximum average EIRP and PSD with transmission power control for the 5.15 GHz to 5.35 GHz range are limited to 23 dBm and 10 dBm / MHz, respectively, and the maximum average EIRP and PSD with transmission power control for the 5.47 GHz to 5.725 GHz range are limited to 30 dBm and 17 dBm / MHz, respectively.

[0009] In addition, the OCB is defined as the bandwidth containing 99% of the signal power, and in some regions, it should be greater than a percentage of the nominal channel bandwidth (NCB) (i.e., the listen-before-talk (LBT) channel width). This situation forces unlicensed technologies to use a major portion of the channel bandwidth when accessing the channel. According to ETSI, for the 5 GHz band, the OCB should be between 70% and 100% of the NCB.

[0010] Due to the regulations on EIRP, PSD, and OCB described above, the new radio unlicensed (NR-U) supports a frequency interleaved structure in the physical uplink control channel (PUCCH) / physical uplink shared channel (PUSCH), such that the associated resource blocks (RBs) are extended within the subbands available for transmission.

[0011] Interleaved Uplink Design for Unlicensed Access in NR

[0012] In Release 15, PUSCH resources in the frequency domain can have two types of resource mapping, Type 0 and Type 1. For Type 0, the resource allocation information is included in downlink control information (DCI) 0_0 or DCI 0_1, which indicates the bitmap of RB groups (RBGs). An RBG is a set of consecutive virtual RBs defined by the RBG size in the pusch configuration and the size of the bandwidth part (BWP). For Type 1, in DCI 0_0 or DCI 0_1, the resource indication value (RIV) corresponding to the starting virtual RB RB start and the length L RBs of the continuously allocated RBs is signaled to the UE.

[0013] In NR-U, the PUSCH resources in the frequency domain support an interleaved structure, and the associated resource allocation information can be signaled together with a set of interleaving indicators. If the subcarrier spacing (SCS) = 15 kHz, a set of interleaving indicators represented by a 6-bit RIV value is signaled, and if SCS = 30 kHz, a set of interleaving indicators indicated by a 5-bit bitmap is signaled. The interleaving indicator information can be signaled in DCI 0_1 for scheduling PUSCH, DCI 0_1 of type 2 for activating configuration grants, radio resource control (RRC) configuration of type 1 for configuration grants, and DCI 0_0 scrambled by a temporary cell-radio network temporary identifier (TC-RNTI). When considering different numbers of total interleaves, different signals in SCS = 15 kHz and SCS = 30 kHz are used to solve the additional burden of resource allocation signaling, that is, 5 interleaves for SCS = 30 kHz and 10 interleaves for SCS = 15 kHz. Specifically, for SCS = 15 kHz, consecutive interleaving indicators signaled by the RIV allow PUSCH resource allocation. To improve resource allocation flexibility, for RIV ≥ 55, some non-consecutive interleaving indicators m0 + l can be assigned based on the RIV value and the associated interpretation in Table 1 below, where m0 represents the interleaving indicator and l represents the resource block indicator.

[0014] [Table] [1, , ] m0 0 0 {0, 5} 1 0 {0, 1, 5, 6} 2 1 {0, 5} 3 1 {0, 1, 2, 3, 5, 6, 7, 8} 4 2 {0, 5} 5 2 {0, 1, 2, 5, 6, 7} 6 3 {0, 5} 7 4 {0, 5}

[0015] Therefore, when SCS = 15 kHz, a 6-bit RIV instead of a 10-bit bitmap is included in the DCI. For SCS = 30 kHz, there is no restriction on the assigned interleaving index and a 5-bit bitmap is used.

[0016] Interleaving structure

[0017] In addition to the frequency-domain resource mapping in Release 15 for PUSCH and PUCCH, NR-U supports a frequency-domain interleaving structure for mapping to extend RBs within the assigned BWP, where PUCCH resources are restricted within an RB set (e.g., a 20 MHz LBT sub-band) and PUSCH resources can be allocated across multiple RB sets. The configuration of the interleaving structure is consistent between the PUCCH configuration and the PUSCH configuration, i.e., if the PUCCH frequency domain is configured with an interleaving structure, then the PUSCH is also configured with an interleaving structure.

[0018] For SCS = 15 kHz and SCS = 30 kHz, the total number of available interleavings M is 10 and 5, respectively.

[0019] Figure 2 shows an example of the interleaving 0 resources when SCS = 15 kHz.

[0020] Referring to Figure 2, each interleaving is associated with an interleaving index m and contains common RBs (CRBs) with indices {RBstart,m, RBstart,m + M, RBstart,m + 2M,...}, where RBstart,m = m and CRB0 is the reference point. When the PUCCH or PUSCH is configured with an interleaving index in the active BWP, only the RBs within the assigned BWP are allocated.

[0021] SL frame structure

[0022] In NR SL, consider a self - contained approach, whereby each time slot contains control information, data, and in some cases, feedback.

[0023] The control information is carried in SL control information (SCI), and the SL control information is transmitted in two phases. The first - phase SCI is carried on the physical SL control channel (PSCCH) and contains information for sensing operations and information on the resource allocation of the second - phase SCI. The second - phase SCI is transmitted in the physical SL shared channel (PSSCH) resources and is associated with the PSSCH demodulation reference signal (DMRS).

[0024] Figure 3 shows an example where the multiplexing between the PSCCH and the PSSCH is performed in time and frequency within a time slot.

[0025] Referring to Figure 3, the first symbol in the time slot is a replica of the second symbol, which is designed for automatic gain control (AGC) training. The first - stage SCI and 2 or 3 orthogonal frequency - division multiplexing (OFDM) symbols with SCI format 1 - A are carried in the PSCCH. The number of PSCCH symbols is explicitly (pre -)configured for each transmission / reception (Tx / Rx) resource pool using timeResourcePSCCH. The lowest resource block (RB) of the PSCCH is the same as the lowest RB of the corresponding PSSCH. In the frequency domain, the number of RBs in the PSCCH is pre - configured and is not greater than the size of one sub - channel. In this case, if the UE is using multiple consecutive sub - channels for SL transmission within a time slot, the PSCCH will only be present in the first sub - channel.

[0026] The SL-shared channel (SCH) transport channel for transport blocks (TBs) carrying data above the SL and the Phase 2 SCI are carried above the PSSCH. The Phase 2 SCI starts only after the first DMRS symbol in the PSSCH, such that the Phase 2 SCI can have a good channel estimate due to its proximity to the DMRS symbol. Thus, the Phase 2 SCI can occur after some data has been transmitted. The resources for transmitting the PSCCH / PSSCH can be scheduled or configured by the gNB (next-generation Node B) (i.e., Mode 1), or determined via a sensing procedure autonomously initiated by the transmitting UE (i.e., Mode 2).

[0027] The feedback (if it exists) is carried above the physical SL feedback channel (PSFCH). The PSFCH can be used to transmit feedback information from the Rx UE to the Tx UE and can be used for unicast and multicast option 2 / 1. In the case of unicast and multicast option 2, the PSFCH is used to transmit acknowledgement / negative acknowledgement (ACK / NACK), while for the case of multicast option 1, the PSFCH carries only NACK. For SL feedback, a sequence-based PSFCH format (PSFCH format 0) with one symbol (excluding the AGC training period) is supported.

[0028] In PSFCH format 0, the ACK / NACK bits are transmitted via two Zadoff-Chu (ZC) sequences of length 12 (with the same root but different cyclic shifts), whereby the presence of one sequence indicates ACK and the presence of the other sequence indicates NACK (i.e., these sequences are used in a mutually exclusive manner).

[0029] Mapped to PSFCH resources

[0030] In NR SL, three types of PSFCH-based transmissions are considered based on the following broadcast types: Unicast transmission, where the Rx UE provides ACK / NACK to the Tx UE after a request (i.e., when hybrid automatic repeat request (HARQ) is enabled by the Tx UE in the corresponding SCI); Multicast transmission option 2, where each of the expected Rx UEs within the group provides ACK / NACK to the Tx UE after a request (i.e., when HARQ is enabled for the Tx UE in the corresponding SCI); and Multicast option 1, where each of the expected Rx UEs within the group provides a NACK only when it cannot receive and when it is within the area covered by the Tx UE as indicated by the SCI. Here, all UEs use the same PSFCH sequence to provide the NACK.

[0031] For each PSCCH / PSSCH transmission, a set of corresponding PSFCH resources is identified based on the mapping rule. The set contains multiple RBs and is in a specific time slot corresponding to the PSCCH / PSSCH transmission. Within each RB, there are 12 subcarriers, which allow the transmission of up to 12 orthogonal ZC sequences. To provide feedback, each UE uses two sequences (i.e., one sequence for transmitting ACK and another sequence for transmitting NACK) based on the Tx UE entity identifier.

[0032] It can be scheduled by the SCI format to indicate to the UE in one or more subchannels from several subchannels to receive the PSSCH to transmit a PSFCH with HARQ-ACK information in response to the PSSCH reception. The UE can provide HARQ-ACK information containing ACK or NACK or only NACK.

[0033] The UE can provide the number of time slots in the resource pool for the period of the PSFCH transmission timing resource by sl-PSFCH-Period-r16. If the number is zero, the PSFCH transmission from the UE in the resource pool is disabled.

[0034] The UE expects a time slot ) with a PSFCH transmission timing resource, if , where k is the time slot of T'max time slots, Mod is the mathematical operation that returns the remainder when one number is divided by another number, is the number of time slots belonging to the resource pool within 10240 milliseconds and is provided by sl-PSFCH-Period-r16.

[0035] The UE can be indicated by the higher layer not to transmit a PSFCH in response to the PSSCH reception.

[0036] If the UE receives a PSSCH in a resource pool and the HARQ feedback enable / disable indicator field in the associated SCI format 2-A or SCI format 2-B has a value of 1, the UE provides HARQ-ACK information in the PSFCH transmission in the resource pool. The UE transmits the PSFCH in the first time slot, which contains the PSFCH resource and is at least a number of time slots in the resource pool (provided by sl-MinTimeGapPSFCH-r16) after the last time slot in which the PSSCH was received.

[0037] sl-PSFCH-RB-Set-r16 provides the UE with a set of physical RBs (PRBs) in the resource pool for PSFCH transmission in the PRBs of the resource pool. For the number of subchannels (provided by sl-NumSubchannel) and the number of PSSCH time slots associated with the PSFCH time slot (which is less than or equal to ), the UE will allocate the PRBs from the PRB allocation to time slot i among the PSSCH time slots associated with the PSFCH time slot and subchannel j, where , , and the allocation starts in ascending order of i and continues in ascending order of j. The UE expects to be a multiple of.

[0038] The UE determines the number of PSFCH resources available for multiplexing HARQ-ACK information in the PSFCH transmission to be , where is the number of cyclic shift pairs for the resource pool, and is based on a higher layer indication: and the PRB is associated with the starting subchannel of the corresponding PSSCH; and and the PRB is associated with one or more subchannels from the corresponding PSSCH subchannels.

[0039] The PSFCH resources are first determined according to the ones from Index the PRB indicators of the PRB in ascending order, and then index the cyclic shift pair indicators of the cyclic shift pairs in ascending order.

[0040] If the UE detects an SCI format 2-A with a broadcast indicator field value of "01", then the UE responds to the PSSCH reception to determine that the indicator of the PSFCH resource for PSFCH transmission is , where is the physical layer source ID provided by the SCI format 2-A or toc that schedules the PSSCH reception, and as indicated by the higher layer, is the identity of the UE that receives the PSSCH; otherwise, is zero.

[0041] The UE obtains the cyclic shift pair indicator corresponding to the PSFCH resource indicator and the interleaving indicator value m0 used to calculate the cyclic shift α from Table 2 below.

[0042] [Table] [2] [, , ] Cyclic shift pair indicator 0 Cyclic shift pair indicator 1 Cyclic shift pair indicator 2 Cyclic shift pair indicator 3 Cyclic shift pair indicator 4 Cyclic shift pair indicator 5 1 0 - - - - - 2 0 3 - - - - 3 0 2 4 - - - 6 0 1 2 3 4 5

[0043] If the UE detects an SCI format 2-A with a broadcast indicator field value of "01" or "10", as in Table 2, or if the UE detects an SCI format 2-B or SCI format 2-A with a broadcast indicator field value of "11", as in Table 3 or Table 4 below, then the UE determines the interleaving index value m0 used to calculate the cyclic shift α. The UE applies one of the cyclic shifts from the cyclic shift pair to the sequence used for PSFCH transmission.

[0044] [Table] [3] [, , ] HARQ-ACK value 0 (NACK) 1 (ACK) Sequence cyclic shift 0 6

[0045] [, , ] [Table] [4] [, , ] HARQ-ACK value 0 (NACK) 1 (ACK) Sequence cyclic shift 0 N / A

[0046] As shown above, when the HARQ-ACK information contains ACK or NACK, or when the HARQ-ACK information contains only NACK, Table 3 and Table 4 can be used to map the HARQ-ACK information bit values to the cyclic shifts of the cyclic shift pairs of the sequences used for PSFCH transmission, respectively.

[0047] NR Sidelink Mode 2 Resource Allocation Procedure

[0048] The Release 16 SL Mode 2 resource allocation procedure [TS 38.214] provides: 8.1.4 UE procedure for determining a subset of resources to be reported to the higher layer in the selection of resources for PSSCH in sidelink resource allocation mode 2.

[0049] In resource allocation mode 2, the higher layer may request the UE to determine a subset of resources, from which the higher layer will select the resources for PSSCH / PSCCH transmission. To trigger this procedure, in slot n, the higher layer provides the following parameters for this PSSCH / PSCCH transmission: - Resource pool from which to report resources; - L1 priority, ; - Remaining packet delay budget; - Number of subchannels available for PSSCH / PSCCH transmission in the slot, ; - Optionally, resource reservation interval , in ms. - If the higher layer requests the UE to determine a subset of resources (the higher layer will select the resources for PSSCH / PSCCH transmission from the subset of resources as part of a re-evaluation or pre-procedure), the higher layer provides the set of resources that can be subject to re-evaluation and the set of resources that can be subject to pre- . - Until the UE implements the determination of the subset of resources as requested by the higher layer before or after slot to where is and the slot with the smallest slot index and is equal to , where is defined in the slot in Table 8.1.4-2, where is the SCS configuration of the SL BWP.

[0050] The following higher layer parameters affect this procedure: - sl-SelectionWindowList: For a given value , the internal parameter is set to the corresponding value from the higher layer parameter sl-SelectionWindowList. - sl-ThresPSSCH-RSRP-List: This higher layer parameter provides the reference signal received power (RSRP) threshold for each combination , where is the value of the priority field in the received SCI format 1-A and is the priority of the transmission of the UE selected resource; for a given invocation of this procedure, . - sl-RS-ForSensing selects whether the UE uses PSSCH-RSRP measurement or PSCCH-RSRP measurement, as defined in clause 8.4.2.1. - sl-ResourceReservePeriodList-r16 - sl-SensingWindow: The internal parameter is defined as the number of slots corresponding to sl-SensingWindowms. - sl-TxPercentageList: For a given , the internal parameter is defined as the sl-TxPercentageList converted from percentage and ratio ( ). - sl-PreemptionEnable: If sl-PreemptionEnable-r16 is provided and if it is not equal to 'enabled', then the internal parameter is set to the higher layer that provides the parameter sl-PreemptionEnable.

[0051] If provided , then the resource reservation interval is converted from units of ms to units of logical time slots, resulting in . Notation: Refers to the set of time slots that can belong to the sidelink resource pool and is defined in Clause 8.

[0052] Use the following steps: 1) The candidate single time slot resource for transmission is defined as the set of contiguous subchannels in time slot with subchannel x + j, where . The UE shall assume that any set of contiguous subchannels in the corresponding resource pool contained within the time interval corresponds to a candidate single time slot resource, where - The selection of is performed by the UE at most under where is defined in the time slots in Table 8.1.4-2, where is the SCS configuration of the SL BWP; - If is shorter than the remaining packet delay budget (in the time slot), then depends on the UE implementation subject to the remaining packet budget (in the time slot); otherwise is set to the remaining packet delay budget (in the time slot). The total number of candidate single time slot resources is represented by

[0053] . 2) The sensing window is defined by time slot ), where is defined above and ​in the time slots defined in Table 8.1.4-1, where is the SCS configuration of the SL BWP. The UE shall monitor the time slots within the sensing window that can belong to the sidelink resource pool other than the time slots in which its own transmission occurs. The UE shall perform the actions in the following steps based on the decoded PSCCH and the measured RSRP in these time slots. 3) Internal parameter is set to the corresponding value of the RSRP threshold indicated by the i-th field in sl-ThresPSSCH-RSRP-List-r16, where . 4) Set is initialized to the set of all candidate single time slot resources. 5) If the UE meets all of the following conditions, it shall exclude any candidate single time slot resource from the set : - The UE has not monitored the time slot in step 2 . - For any periodic value allowed by the higher layer parameter sl-ResourceReservePeriodList-r16 and for the time slots with the "resource reservation period" field set to that periodic value the hypothetical SCI format 1-A received and indicating all sub-channels of the resource pool in this time slot will meet the condition c in step 6. 6) If the UE meets all of the following conditions, it shall exclude any candidate single time slot resource from the set : - a) The UE is in the time slot ​Receive SCI format 1-A, and the "Resource Retention Period" field (if present) and the "Priority" field in the received SCI format 1-A are respectively based on the item 16.4 indication value in [6, TS 38.213] and ; b) The RSRP measurement performed on the received SCI format 1-A according to item 8.4.2.1 is higher than c) In the time slot The SCI format received or if and only if the "Resource Retention Period" field exists in the received SCI format 1-A, then assume that the same SCI format received in the time slot Determine the resource block set and the time slots overlapping with for q = 1, 2,..., Q and j = 0, 1,... according to item 8.1.5 Here, if and , where , if the time slot n belongs to the set , then is the converted into a logical time slot unit according to item 8.1.7 , otherwise the time slot is the first time slot after the time slot n belonging to the set . Set the selection window size T2 converted into units of ms. 7) If the number of remaining candidate single time slot resources in the set is less than , then for each priority value , Increase by 3 dB, and the program continues with step 4.

[0054] The UE shall report the set .

[0055] If the resources from the set ​ Not a member of, the UE shall report the resource re - evaluation report to the higher layer.

[0056] If the resource from the set is not a member caused by the exclusion in step 6 above, then compare with the RSRP measurement result of the received SCI format 1 - A with the associated priority and meet one of the following conditions. Then the UE shall report the resource pre - report to the higher layer. - sl - PreemptionEnable is provided and equal to 'Enabled' and - sl - PreemptionEnable is provided and not equal to 'Enabled', and - sl - PreemptionEnable is provided and not equal to 'Enabled', and and

[0057] Table 8.1.4 - 1: Depending on the sub - carrier spacing [Time slot] 0 1 1 1 2 2 3 4

[0058] Table 8.1.4 - 2: Depending on the sub - carrier spacing [Time slot] 0 3 1 5 2 9 3 17

[0059] As described above, for transmissions in the unlicensed band, the rules require that the UE occupy a substantial fraction of the channels in the frequency domain such that the PSD and OCB constraints are met. However, the current design of SL transmissions relies on the use of local transmissions in the frequency. Therefore, a new mapping from physical channels to physical RBs for SL unlicensed communication is needed. SUMMARY

[0060] To solve this problem, according to an embodiment of the present disclosure, an interleaved design is provided that allows the use of existing SL procedures with minimal modifications. That is, a method and apparatus are provided for performing SL communication on an unlicensed band using a frequency interleaved design to meet the OCB requirements and allow a higher total transmission power without exceeding a certain PSD limit. Although the mapping to physical RBs (PRBs) is different, the existing procedures can still be reused. Specifically, no changes are applied to the SCI format, and the version 16 / version 17 mapping rules of the PSFCH are maintained.

[0061] In an embodiment, a UE is provided, the UE comprising: a transceiver; and a processor configured to determine whether the UE is operating in a local mode or an interleaved mode for SL communication; and in response to determining that the UE is operating in the interleaved mode, decode a first-stage SCI of a physical SL control channel (PSCCH) based on an interleaved mapping scheme, decode a second-stage SCI of a physical SL shared channel (PSSCH) based on the decoded first-stage SCI, and decode the PSSCH based on the decoded first-stage SCI and the decoded second-stage SCI.

[0062] In an embodiment, a method performed by a UE comprises: determining whether the UE is operating in a local mode or an interleaved mode for SL communication; and in response to determining that the UE is operating in the interleaved mode, decode a first-stage SL control information (SCI) of a physical SL control channel (PSCCH) based on an interleaved mapping scheme, decode a second-stage SCI of a physical SL shared channel (PSSCH) based on the decoded first-stage SCI, and decode the PSSCH based on the decoded first-stage SCI and the decoded second-stage SCI. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] In the following sections, aspects of the subject matter disclosed herein will be described with reference to exemplary embodiments shown in the drawings, in which: FIG. 1 shows an example of the control path and data path of NCIS. FIG. 2 shows an example of interleaved 0 resources when SCS = 15 kHz. FIG. 3 shows an example in which the multiplexing between the PSCCH and the PSSCH is performed in terms of time and frequency within a time slot. FIG. 4 shows an example of the frequency interleaved to the PSSCH that may occur in a shared radio band or an unlicensed band according to an embodiment. FIG. 5 is a flowchart showing a UE operation for determining a subchannel / interleaving size according to an embodiment. FIG. 6 shows a PSSCH / PSCCH multiplexing option 1 according to an embodiment. FIG. 7 shows a PSSCH / PSCCH multiplexing option 2 according to an embodiment. FIG. 8 shows a PSSCH / PSCCH multiplexing option 3 according to an embodiment. FIG. 9 shows a PSSCH / PSCCH multiplexing option 4 according to an embodiment. FIG. 10 is a flowchart showing a procedure of a UE receiving a PSSCH according to an embodiment. FIG. 11 shows SL communication using a frequency interleaved waveform with one or more additional frequency interleavings that can be assigned for PSSCH communication according to an embodiment. FIG. 12 shows another SL communication scheme using a frequency interleaved waveform according to an embodiment. FIG. 13 shows an example of a PSFCH structure and an associated mapping according to an embodiment. FIG. 14 is a flowchart showing a method of transmitting a PSFCH according to an embodiment. FIG. 15 is a block diagram of an electronic device in a network environment according to an embodiment. Embodiments

[0064] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. However, those skilled in the art will understand that the disclosed aspects may be practiced without these specific details. In other instances, well-known methods, procedures, components, and circuits have not been described in detail so as not to obscure the subject matter disclosed herein.

[0065] In this specification, a reference to "an embodiment" or "an example embodiment" means that the particular features, structures, or characteristics described in connection with the embodiment may be included in at least one embodiment disclosed herein. Thus, the appearances of the phrases "in an embodiment," "in embodiments," "according to an embodiment" (or other phrases with similar meanings) at various places throughout this specification are not necessarily all referring to the same embodiment. Additionally, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In this regard, as used herein, the word "exemplary" means "serving as an example, instance, or illustration." Any embodiment described herein as "exemplary" should not be construed as being preferred or advantageous over other embodiments. Further, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Also, depending on the context of the discussion herein, singular terms may include the corresponding plural forms, and plural terms may include the corresponding singular forms. Similarly, hyphenated terms (e.g., "two-dimensional," "pre-determined," "pixel-specific," etc.) may be used interchangeably with their corresponding non-hyphenated versions (e.g., "two dimensional," "predetermined," "pixel specific," etc.), and capitalized terms (e.g., "Counter Clock," "Row Select," "PIXOUT," etc.) may be used interchangeably with their corresponding non-capitalized versions (e.g., "counter clock," "row select," "pixout," etc.). Such interchangeable use should not be regarded as inconsistent with each other.

[0066] Also, depending on the context of the discussion herein, singular terms may include the corresponding plural forms, and plural terms may include the corresponding singular forms. It should be further noted that the various diagrams (including component diagrams) illustrated and discussed herein are for illustrative purposes only and are not drawn to scale. For example, for clarity, the dimensions of some of the elements may be enlarged relative to other elements. Additionally, where considered appropriate, reference numerals have been repeated in the figures to indicate corresponding and / or similar elements.

[0067] The terms used herein are for the purpose of describing some exemplary embodiments only and are not intended to limit the claimed subject matter. As used herein, unless the context clearly indicates otherwise, the singular forms "a" and "the" are also intended to include the plural forms. It should be further understood that the term "comprising", when used in this specification, specifies the presence of the stated features, integers, steps, operations, elements and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0068] It should be understood that when an element or layer is referred to as being "on", "connected to" or "coupled to" another element or layer, the element or layer can be directly on, directly connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on", "directly connected to" or "directly coupled to" another element or layer, there are no intervening elements or layers. The same reference numerals throughout the text refer to the same elements. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0069] The terms "first", "second", etc. as used herein are labels for the nouns that precede them and do not imply any type of ordering (e.g., spatial, temporal, logical, etc.), unless so explicitly defined. In addition, the same reference numerals may be used in two or more figures to refer to parts, components, blocks, circuits, units or modules having the same or similar functionality. However, this usage is for simplicity of illustration and ease of discussion only; it does not imply that the construction or architectural details of such components or units are the same in all embodiments, or that such commonly referred to parts / modules are the only way to implement some of the exemplary embodiments disclosed herein.

[0070] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this subject matter belongs. It should be further understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0071] As used herein, the term "module" refers to any combination of software, firmware, and / or hardware configured to provide the functionality described herein in connection with the module. For example, software can be embodied as a software package, code, and / or instruction set or instructions, and the term "hardware" as used in any implementation described herein can include, alone or in any combination, for example, an assembly, a wired circuit system, a programmable circuit system, a state machine circuit system, and / or firmware storing instructions executed by the programmable circuit system. A module can be embodied, jointly or individually, as a circuit system forming part of a larger system, such as, but not limited to, an integrated circuit (IC), a system on a chip (SoC), an assembly, and the like.

[0072] To meet the above PSD and OCB adjustment requirements, the present disclosure constructs on the NR-U framework by defining an interleaving structure when mapping the SL channel to a resource block.

[0073] FIG. 4 shows an example of the frequency interleaved to the PSSCH that can occur on a shared radio band or an unlicensed band according to an embodiment.

[0074] Referring to FIG. 4, the available RBs are divided into K clusters (C(0) to C(K-1)). Each of these clusters contains M RBs.

[0075] To perform interleaving, the PSSCH should be spread in frequency. To achieve this, M interleaves (i.e., I(0), I(1),..., I(M-1)) are defined, where each interleave occupies one RB from each cluster. For example, the first interleave (i.e., I(0)) will occupy the first RB (i.e., RB0) in each of the K clusters. Thus, the first interleave will occupy the RBs (0, M, 2M,..., (K-1)*M) and the interleave i will occupy the RBs i, (i+M,..., i+(K-1)*M). In general, an interleave can be defined by an offset value (between 0 and M-1) indicating the first RB used in the frequency.

[0076] Alternatively, the interleaving can be defined on another resource granularity, rather than on a single RB (e.g., a group of RBs or a fraction of an RB (e.g., ½ RB)).

[0077] Conceptually, to map frequency interleaved lines to the current SL design, an interleaving can be defined as equivalent to a subchannel, but without contiguous resources, where resources are distributed in frequency. Thus, an interleaving can be regarded as a "virtual subchannel".

[0078] Alternatively, more than one frequency interleaving can be (pre-)defined as a "virtual subchannel", depending on the size of the "virtual subchannel". The mapping between the interleaving and the subchannel can be pre-configured or configured for the RRC of each resource pool.

[0079] The interleaving can be (pre-)configured by RRC signaling. According to an embodiment of the present disclosure, no new signaling is required. The RRC configuration structure for the resource pool (i.e., SL_ResourcePool) can be reused "as is". However, the actual mapping of PRBs will change in the sense of assuming contiguous PRBs when operating in the licensed spectrum and interleaved PRBs when operating in the unlicensed spectrum.

[0080] In addition, once the bandwidth and subchannel size are known, the interleaving (e.g., the number of clusters and the cluster size) can be automatically obtained by the UE. For example, when the bandwidth is 100 PRBs and the subchannel size is 10 PRBs (i.e., 10 subchannels occupy the bandwidth), the UE can automatically infer when operating in the unlicensed band that it will have an interleaved structure, thereby defining 100 / 10 clusters, each with 10 PRBs. Subsequently, when mapping its subchannels via the transmission of actual RBs, the same method can be followed to identify 10 interleavings and thus follow the interleaving mapping role. In other words, when the UE operates in the licensed spectrum, the UE interprets the sl-SubchannelSize (i.e., the parameter providing the subchannel size in the PRBs) as indicating the size of the subchannel in contiguous RBs, while when the UE operates in the unlicensed spectrum, the UE interprets this parameter as belonging to the PRBs interleaved with a given comb factor.

[0081] FIG. 5 is a flowchart showing UE operation for determining subchannel / interleaving size according to an embodiment. More specifically, FIG. 5 shows a method of selecting interleaved or contiguous operation based on the use of licensed / unlicensed spectrum.

[0082] Referring to FIG. 5, in step 501, the UE determines whether it is operating in the licensed spectrum or the unlicensed spectrum.

[0083] In response to the determination in step 501 to operate in the unlicensed spectrum, in step 503, the UE uses the parameter sl-SubchannelSize of the Sl-ResourcePool as an indicator of the number of interleaves and calculates the comb factor based on the total number of available RBs.

[0084] However, in response to the determination in step 501 to operate in the licensed spectrum, in step 505, the UE uses the parameter sl-SubchannelSize (an indicator of the size of the subchannel) of the SL-ResourcePool.

[0085] Although FIG. 5 above has described making a determination using the licensed / unlicensed spectrum, this is only an example. Alternatively, the present disclosure may rely on other parameters, or may be based on all new RRC parameters.

[0086] In addition, determining whether the UE operates in the licensed or unlicensed spectrum may be pre-configured. For example, the unlicensed band may be pre-configured in the UE, and based on its carrier frequency, the UE can identify whether it operates in the licensed or unlicensed band.

[0087] In some cases, the PSSCH may occupy one or more interleaves. The interleave allocation can be performed in a manner similar to subchannel allocation, but where the interleave is the atomic block for resource allocation. That is, the interleave structure is configured separately (i.e., the number of interleaves and the number of RBs in each interleave) from the subchannel size. Subsequently, the subchannel size can be mapped to one or more interleaves depending on its size. For example, if the subchannel size is 20 PRBs and the interleave has 10 PRBs, then each subchannel will be mapped to 2 interleaves.

[0088] Each frequency interleave may contain K PRBs, which are evenly spaced within the band, where K is a positive integer and i can vary between 0 and M-1. Therefore, the PRBs in a particular frequency interleave are spaced apart from each other by at least one other PRB. For example, as described above with reference to FIG. 4, the frequency interleave may contain RBs from clusters C(0) to C(K-1), where each interleave occupies one RB in each cluster. However, the values of K and M may vary based on several factors, such as bandwidth, SCS, and / or PSD limitations of the band. In addition, the number of clusters or the value of K may depend on the amount of frequency distribution required to maintain a certain bandwidth occupancy.

[0089] In this document, two PSSCH transmission modes are described; localized PSSCH transmission and interleaved PSSCH transmission.

[0090] In localized PSSCH transmission, a contiguous RB structure is used and the transmission is based on Release 17 mapping. In interleaved PSSCH transmission, interleaving is used for PSSCH transmission as will be described below.

[0091] PSCCH structure and multiplexed PSSCH

[0092] In Release 16, as described above, the PSCCH is located on a subset of the PRBs used for PSSCH (i.e., depending on the configuration) and in the case where the UE transmission occupies multiple subchannels, it is located in the first subchannel. However, this structure cannot be precisely reused for interleaved PSSCH, and thus a new PSCCH structure and new rules for linking the PSCCH to its associated PSSCH are needed. Different options for the multiplexing pattern between the PSCCH and the PSSCH can be configured by the gNB (next-generation Node B), or can be preconfigured for each SL resource pool.

[0093] Option 1: The PSCCH is located in one or more of the lowest interleaved PRBs. The PSCCH occupies a subset of the PRBs as its associated PSSCH. This depends on the number of frequency interleaves per PSCCH subchannel and the number of interleaves per PSSCH subchannel and the number of interleaves used by the UE for transmission. The PSCCH can occupy some or all of the symbols in which transmission is possible (possibly excluding some, such as guard symbols, AGC symbols, PSFCH symbols, etc.).

[0094] FIG. 6 shows PSSCH / PSCCH multiplexing option 1 according to an embodiment.

[0095] Referring to FIG. 6, it can be seen that this option is similar to the current SL design, except that the PRBs are interleaved and non-contiguous.

[0096] Option 2: Both the highest and lowest interleaved PRBs are used for transmitting the PSCCH. Option 2 is provided to ensure frequency diversity gain because the PRBs will be highly separated in frequency. In Option 2, a new parameter can be provided to indicate how the PSCCH PRBs are split between the highest and lowest PRBs, and the highest and lowest PRBs can be configured according to each resource pool. For example, configuring the PSCCH size in terms of PRBs and configuring the new parameter to 5 will indicate the use of 5 lowest and 5 highest interleaved PRBs. The remaining interleaved PRBs are available for PSSCH transmission.

[0097] FIG. 7 shows the PSSCH / PSCCH multiplexing option 2 according to an embodiment.

[0098] Referring to FIG. 7, the PSCCH has a size of 2 PRBs, and the lowest PRB and the highest PRB are used for the PSCCH.

[0099] Option 3: The PSCCH is located in all (or a part) of the frequency interleaving, but only a part of the available symbols is used. The unused symbols can remain empty or be used for PSSCH transmission. Alternatively, the unused symbols can be used to transmit an independent PSCCH (e.g., for other UEs).

[0100] FIG. 8 shows the PSSCH / PSCCH multiplexing option 3 according to an embodiment.

[0101] Referring to FIG. 8, the BS can configure the first time period of the PSCCH and the second time period of the PSSCH. The first time period can be adjacent to the second time period to reduce the LBT delay. For example, a single LBT can be performed before the first time period and the second time period for transmitting the PSCCH and the PSSCH.

[0102] In some cases, the second time period of the PSSCH can include more symbols than the first time period of the PSCCH.

[0103] In some cases, the first time period can include about 1 - 2 OFDM symbols of the PSCCH, and the second time period can include 10 - 11 symbols of the PSSCH.

[0104] In some cases, the length of the first time period of the PSCCH can be predetermined.

[0105] The first UE can transmit the SCI in the PSCCH to the second UE during the first time period, and the second UE can perform blind decoding in the time period to receive the SCI. Although the PSSCH and the PSCCH communicate during different time periods, for each PSSCH communication, the PS can include an interleaved waveform.

[0106] Option 3 is similar to the option of the current SL structure when the UE uses only one subchannel for transmission and the size of the PSCCH subchannel is set to be equal to the size of the PSSCH subchannel. In this case, the PSCCH occupies the 2nd or 3rd OFDM symbol or the 2nd, 3rd, and 4th OFDM symbols in each time slot.

[0107] Option 4: The PSCCH is located on all RBs where the PSSCH is transmitted and is located on all available symbols. Multiplexing is performed within the PRB. For example, the subcarrier with the lowest index is reserved for the PSCCH.

[0108] Figure 9 shows the PSSCH / PSCCH multiplexing option 4 according to an embodiment.

[0109] The different options of the multiplexing pattern between the PSCCH and the PSSCH as described above can be configured by the gNB for each resource pool or for each SL UE, or can be pre-configured for each SL resource pool.

[0110] Second-stage SCI mapping and structure with PSSCH

[0111] As described above, in SL, the control SCI is sent in two stages. The first-stage SCI is sent in the PSCCH, and the second-stage SCI is sent with the data in the PSSCH. The second-stage SCI can be mapped to the resource elements in the first OFDM symbol that appears after the first DMRS symbol. In this case, depending on its size, the second-stage SCI can be multiplexed with the payload in the PSSCH either in time or frequency. For example, the second-stage SCI fills the subcarriers in the first OFDM symbol in ascending order after the DMRS, and after all the subcarriers in the first OFDM symbol are filled, the subcarriers in the subsequent OFDM symbols are used. This mapping strategy can also be considered here, except that the PRBs where the second-stage SCI is transmitted are interleaved and non-contiguous in the frequency domain.

[0112] PSSCH resource allocation indication

[0113] As described above, two PSSCH mappings are possible; version 16 / 17 mapping to local sub-channels or interleaved mapping.

[0114] These two mappings can be signaled in the same way. That is, for the same number of interleaves as there are sub-channels present, the interleaves can be assigned in the same way as the sub-channels. For example, by treating the frequency resource allocation field of the SCI as an indication of the interleaving indicator, the existing SCI format for the first phase (or at least for frequency resource allocation) can be maintained, and the frequency resource allocation field can be interpreted in the same way as for sub-channel allocation but for interleaving. Similarly, the indication for the second phase SCI can be similar to the indication for the local situation. Thus, the existing SCI format 1 can also be used as is for signaling the interleaved PSSCH.

[0115] Blind decoding of the PSCCH can be performed in the same way for the interleaved mode and the local mode. For the local mode, the UE attempts to decode the PSCCH at a specific position linked to the sub-channel. For the interleaved mode, the same procedure can be applied such that the UE attempts to decode the PSCCH at a specific position linked to the interleaving.

[0116] FIG. 10 is a flowchart showing a procedure for a UE to receive a PSSCH according to an embodiment.

[0117] Referring to FIG. 10, in step 1001, the UE determines whether the system is operating with a localized PSSCH or an interleaved PSSCH, that is, operating in the local mode or the interleaved mode. This can be done in several ways. For example, the determination can be based on the system deployment. That is, if the system is in an unlicensed spectrum, the system operates in the interleaved mode. However, if the system is in a licensed spectrum or a spectrum dedicated to vehicle-to-everything (V2X) communication (e.g., the ITS band), the system operates in the local mode.

[0118] There can also be some (pre)-configurations regarding whether to use the localized or interleaved PSCCH (e.g., signaled by RRC). A field sl-Distributed can be added to the SL-ResourcePool IE to indicate whether the UE operates with an interleaved or a localized PSCCH. This allows some resource pools to use the interleaved mapping while others use the localized mapping.

[0119] Once the determination has been made, the UE attempts to blindly decode the PSCCH in step 1003 or step 1005.

[0120] If it is determined to use the local mode, then in step 1005, the UE uses the legacy mapping to view the PSCCH by means of the Release 17 PSCCH to PSSCH mapping rule. However, if it is determined that the UE is in the interleaved mode, then in step 1003, as described above, the UE uses one of mapping options 1 to 4. For both step 1003 and step 1005, the blind detection complexity is the same.

[0121] When performing blind decoding in step 1003 or step 1005, the UE attempts to decode the first-stage SCI. The same SCI format (e.g., SCI format 1A) can be used for both local mapping and interleaved mapping. However, the main difference is the way to interpret the frequency resource allocation field therein. If the mode is localized, the frequency resource allocation field indicates sub-channels, but if the mode is interleaved, the frequency resource allocation field indicates interleaving.

[0122] If the first-stage SCI is not successfully obtained in step 1007 or step 1009, then the UE moves to the next time slot in step 1011.

[0123] After successfully obtaining the first-stage SCI in step 1007 or step 1009, the UE decodes the second-stage SCI in step 1013 or step 1015. The format of the second-stage SCI is the same as that of Release 16 / Release 17. However, as described above, where the second-stage SCI resources are located is different based on the type of mapping (i.e., contiguous in a sub-channel or interleaved in a sub-channel).

[0124] After obtaining both the first-stage and second-stage SCI, the UE attempts to decode the PSSCH in step 1017 or step 1019. Based on the resource allocation field, the PSSCH position is known to the UE. Based on the second-stage SCI, the additional information (e.g., HARQ process ID, destination ID, etc.) for decoding the PSSCH is known.

[0125] Based on the foregoing, the UE can perform sensing in the same way for both the local mode and the interleaved mode. Thus, after the local / interleaved determination, the UE decodes the first-stage SCI and then knows which resources are occupied in terms of interleaving or sub-channels.

[0126] FIG. 11 shows SL communication using a frequency interleaved waveform with one or more additional frequency interleaves for assignable PSSCH communication according to an embodiment. Specifically, FIG. 11 shows that the UE is allocated more than one interleaving for its PSSCH.

[0127] For simplicity purposes, FIG. 11 shows only one additional frequency hopping assignment for PSSCH communication, although this scheme can be applied to assign any suitable number of additional frequency hopping assignments to PSSCH communication (e.g., 2, 3, 4, or more).

[0128] Referring to FIG. 11, similar to FIG. 7, the BS can configure the highest frequency RB(0) and the lowest frequency RB(9) of the frequency hopping of PSCCH, and can configure the remaining RBs in the frequency hopping of PSSCH. The first UE can, for example, assign additional frequency hopping to PSSCH based on the transmission data size.

[0129] While the example of FIG. 11 shows an additional frequency hopping adjacent or contiguous to the frequency hopping, the first UE can assign any other frequency hopping in the frequency band to PSSCH communication. For example, when the frequency band contains M numbers of frequency hoppings from l(0) to l(M - 1), the first UE can assign the frequency hopping m as an additional frequency domain resource for PSSCH communication, where m can be between 1 and M - 1. In some cases, the first UE can include the transmission of PSCCH to indicate to the second UE that the PSSCH communication is further transmitted in the additional frequency hopping l(1), as indicated by the dashed arrow in FIG. 11. The first UE can transmit the SCI in the highest frequency RB(0) and can repeat the transmission of the SCI to the lowest frequency RB(9) of the frequency hopping l(0). Thus, in addition to RB(1) to RB(8) of the frequency hopping l(0), the second UE can also decode the SCI from the PSCCH communication and receive the PSSCH communication from the frequency hopping l(1). The SCI can indicate the resource allocation information for the additional frequency hopping assigned for PSSCH communication using a bitmap or RIV (e.g., RIV in the legacy NR SL SCI).

[0130] In some embodiments, the SL communication can be performed on a wide frequency band (e.g., a BW of about 100 megahertz). The wide frequency band can be divided into multiple sub-bands, for example, each having a BW of 20 megahertz. To facilitate the SL communication, the PSCCH communication can communicate in the frequency hopping within a certain sub-band in the frequency band, and the first UE can assign additional frequency hopping in different sub-bands. The first UE can further indicate in the SCI which sub-band of the additional frequency hopping is among the multiple sub-bands.

[0131] FIG. 12 shows another SL communication scheme using a frequency hopping waveform according to an embodiment.

[0132] In FIG. 12, PSSCH and PSCCH are frequency multiplexed onto the same frequency interleaving l(0), and an additional frequency interleaving l(1) is assigned to PSCCH. This scheme can further assign additional time resources (e.g., a set of time slots) for PSSCH communication.

[0133] For simplicity purposes, FIG. 12 shows only one additional time slot assigned for PSSCH communication, but the scheme can be applied to assign any suitable number of time slots for PSSCH communication (e.g., about 2, 3, 4 or more).

[0134] Different from the current SL design of PSCCH in each subchannel, the scheme in FIG. 12 provides better utilization of resources because more resource elements are available for data transmission. However, this can come at the cost of lower sensing reliability because fewer PSCCHs are sent in the Release 16 system.

[0135] PSFCH Resource Allocation

[0136] Similar to other channels, PSFCH should also be distributed in frequency so as to substantially occupy the entire broadband. In Release 16, PSFCH is frequency localized. Therefore, a new PSFCH resource mapping is needed. Here, two schemes are provided: a first scheme that depends on interleaving at the RB level, and a second scheme that depends on interleaving at the subcarrier level.

[0137] RB Interleaving Scheme

[0138] Here, the interleaving is defined in frequency. For PSFCH transmission, all PRBs of the defined frequency interleaving (e.g., the same frequency interleaving defined for PSSCH) are available for transmitting NACK or ACK in repetitions that span the entire RB set. For example, each interleaving for PSFCH transmission consists of 4 RBs, and similar to PUCCH Release 16 NR-U, each of the 4 RBs is used to transmit the same ACK or NACK.

[0139] FIG. 13 shows an example of a PSFCH structure and associated mapping according to an embodiment.

[0140] Referring to FIG. 13, there are 16 PRBs and 4 interleaves, and the PSFCH is transmitted every other time slot. Therefore, 8 interleaved PSSCHs can be transmitted before the occurrence of the PSFCH. Thus, 8 PSFCH resources in time and frequency are defined. However, it should be noted that more PSFCH resources are available because code division multiplexing (CDM) can be applied to the upper part of each RB.

[0141] As shown in FIG. 13, each interleave occupies 2 PRBs, and the PSFCH is repeated on two RBs of a PSFCH.

[0142] However, repeating the same PSFCH signal across all resource blocks can result in increased cubic metric, thus requiring a greater back-off in the power amplifier. To mitigate this, phase rotation (corresponding to cyclic shift in the time domain) can cycle through several different possibilities among different numbers of values of RBs within the defined interleaves. This phase rotation can be configured for each resource pool and can be applied by all UEs, similar to the concept of frequency hopping in the Uu link. Therefore, this method should not affect the mapping rule of the PSFCH.

[0143] To support the frequency-interleaved PSFCH design, the existing specification of PSFCH resource mapping can be changed from RB-based mapping to frequency-interleaved mapping. More specifically, the UE is provided with a set of (pre-defined) frequency-interleaved sl-PSFCH-Interlace-Set-r18 for PSFCH transmission in the interleaved resource pool. For the number of sub-channels of the resource pool (provided by sl-NumSubchannel) and the number of PSSCH time slots associated with the PSFCH time slot (which is less than or equal to ), the UE will interleave from interleave and allocate to the time slots among the PSSCH time slots associated with the PSFCH time slot and the sub-channel , where , and the allocation starts in the increasing order of , , , , and is allocated to start with and ends with continues in ascending order. The UE expects to be a multiple of.

[0144] The UE determines that the number of PSFCH interleaves available for multiplexing HARQ-ACK information in PSFCH transmission is , where is the number of cyclic shift pairs for the resource pool and is based on a higher layer indication: and the interleaving is associated with the starting subchannel of the corresponding PSSCH; or and the interleaving is associated with one or more subchannels from the subchannels of the corresponding PSSCH.

[0145] The PSFCH resources are indexed first according to the ascending order of the interleaving indicators from the interleaving and then according to the ascending order of the cyclic shift pair indicators from the cyclic shift pairs.

[0146] If the UE detects an SCI format 2-A with a broadcast indicator field value of "01", the UE determines that the indicator of the PSFCH interleaving for PSFCH transmission in response to PSSCH reception is , where is the physical layer source ID provided by the SCI format 2-A or SCI format 2-B for scheduling PSSCH reception, and as indicated by the higher layer, is the identity of the UE receiving the PSSCH; otherwise, is zero.

[0147] Although the PSFCH mapping is different in the above procedure, the same procedure defined in Release 16 for PSSCH to PSFCH mapping can be reused.

[0148] Subcarrier interleaving scheme

[0149] As described above, the RB interleaving scheme is generally suitable when the PSFCH is used for low payloads (e.g., ACK / NACK feedback). However, a possible drawback of this type of method is that the PSFCH capacity may be reduced compared to when the PSSCH is transmitted on local subchannels, due to the repeated transmission of the ACK / NACK sequences to achieve interleaving. To mitigate this possible drawback, subcarrier level interleaving can be performed, as described below.

[0150] Subcarrier level interleaving can be performed by using a comb structure at the subcarrier level (or subcarrier group). For example, the current PSFCH design occupies 1 PRB, which is equivalent to 12 resources at the subcarrier level. To maintain the same format and the same payload as in Release 16, the following operations are performed: ● Determine the number of PRBs N in the carrier. ● Determine the comb factor as N. Thus, the number of PSFCH interleavings is the same as the number of PRBs in the legacy system. Therefore, the number of PSFCH resources is the same as the interleaving case for the local subchannel case. Therefore, there is no loss of capacity on the PSFCH.

[0151] Interleaving at the subcarrier level can be performed in several ways. One method is to use interleaved frequency division multiple access (IFDMA) modulation with a repetition factor k. Another method is to use OFDM, but transmit only on a limited number of subcarriers by following a comb structure similar to that used by the channel state information reference signal (CSI-RS). This is sometimes referred to as interleaved OFDM.

[0152] Given that there are the same number of PSFCH resources for interleaving the PSFCH as in the legacy PSFCH, the mapping rules from PSSCH to PSFCH can be the same for both the interleaving and local subchannel cases, which is an advantage of this scheme. Additionally, in the case of multicast option 2, the same multicast group size can be supported. Finally, for the side information transmitted on the PSFCH in the Release 17 scheme, if the subcarrier interleaving method is used, there will be the same capacity to support the side information.

[0153] As another improvement, adjacent interleaving can be avoided whenever possible in order to limit inter-carrier interference (ICI). This can be done by indexing adjacent interleaving in a non-adjacent manner. For example, if the MPSSCH interleaving is defined, the PSFCH interleaving l can start at the subcarrier index l*N / M. Conceptually, this is the same as a local sub-channel, where N / M is equal to the channel size. For a local RB, the PSFCH is set on RB0, N / M, 2N / M. For interleaving, basically the same rules can be applied.

[0154] Figure 14 is a flowchart showing a method of transmitting a PSFCH according to an embodiment.

[0155] Referring to Figure 14, in step 1401, the UE receives the PSSCH.

[0156] In step 1403, the UE determines whether feedback will be transmitted on the PSFCH. If there is no feedback, then in step 1405 the UE moves to the next time slot.

[0157] However, if there is feedback in step 1403, then the UE determines the PSFCH resource index in step 1407. The determination for the local mode and the interleaving mode is the same.

[0158] In step 1409, the UE determines whether to use the local mode or the interleaving mode. When the UE uses the local mode, the version 17 procedure is used to transmit the PSFCH regarding the determined index in step 1411. However, when the UE uses the interleaving mode, an interleaved PSFCH mapping (for example, any of the RB or subcarrier interleaving methods described above) is used in step 1413. The choice between the two interleaving methods can be made based on the RRC configuration.

[0159] Figure 15 is a block diagram of an electronic device in a network environment 1500 according to an embodiment. For example, the electronic device 1501 can be a UE for executing the above procedures and solutions.

[0160] Referring to FIG. 15, the electronic device 1501 in the network environment 1500 can communicate with the electronic device 1502 via the first network 1598 (e.g., a short-range wireless communication network), or communicate with the electronic device 1504 or the server 1508 via the second network 1599 (e.g., a long-range wireless communication network). The electronic device 1501 can communicate with the electronic device 1504 via the server 1508. The electronic device 1501 may include a processor 1520, a memory 1530, an input device 1540, a sound output device 1555, a display device 1560, an audio module 1570, a sensor module 1576, an interface 1577, a tactile module 1579, a camera module 1580, a power management module 1588, a battery 1589, a communication module 1590, a subscriber identification module (SIM) card 1596, or an antenna module 1597. In one embodiment, at least one of the components (e.g., the display device 1560 or the camera module 1580) may be omitted from the electronic device 1501, or one or more other components may be added to the electronic device 1501. Some of the components may be implemented as a single integrated circuit (IC). For example, the sensor module 1576 (e.g., a fingerprint sensor, an iris sensor, or an illuminance sensor) may be embedded in the display device 1560 (e.g., a display).

[0161] The processor 1520 may execute software (e.g., the program 1540) to control at least one other component (e.g., a hardware or software component) of the electronic device 1501 coupled to the processor 1520, and may perform various data processing or calculations.

[0162] As at least part of data processing or computing, the processor 1520 may load commands or data received from another component (e.g., the sensor module 1546 or the communication module 1590) in the volatile memory 1532, process the commands or data stored in the volatile memory 1532, and store the resulting data in the non-volatile memory 1534. The processor 1520 may include a main processor 1521 (e.g., a central processing unit (CPU) or an application processor (AP)) and an auxiliary processor 1523 (e.g., a graphics processing unit (GPU), an image signal processor (ISP), a sensor hub processor, or a communication processor (CP)), and the auxiliary processor 1523 may operate independently of the main processor 1521 or in combination with the main processor 1521. Additionally or alternatively, the auxiliary processor 1523 may be used to consume less power than the main processor 1521 or perform specific functions. The auxiliary processor 1523 may be implemented as separate from the main processor 1521 or as part of the main processor 1521.

[0163] The auxiliary processor 1523 may control at least some of the functions or states related to at least one of the components (e.g., the display device 1560, the sensor module 1576, or the communication module 1590) among the components of the electronic device 1501 instead of the main processor 1521 when the main processor 1521 is in a non-active (e.g., sleep) state or together with the main processor 1521 when the main processor 1521 is in an active state (e.g., executing an application). The auxiliary processor 1523 (e.g., an image signal processor or a communication processor) may be implemented as part of another component (e.g., the camera module 1580 or the communication module 1590) that is functionally related to the auxiliary processor 1523.

[0164] The memory 1530 may store various data used by at least one of the components of the electronic device 1501 (e.g., the processor 1520 or the sensor module 1576). The various data may include, for example, software (e.g., the program 1540) and input data or output data for commands related thereto. The memory 1530 may include the volatile memory 1532 or the non-volatile memory 1534.

[0165] The program 1540 can be stored as software in the memory 1530 and can include, for example, an operating system (OS) 1542, middleware 1544, or an application 1546.

[0166] The input device 1550 can receive commands or data from the outside of the electronic device 1501 (e.g., a user) to be used by another component of the electronic device 1501 (e.g., the processor 1520). The input device 1550 can include, for example, a microphone, a mouse, or a keyboard.

[0167] The sound output device 1555 can output a sound signal to the outside of the electronic device 1501. The sound output device 1555 can include, for example, a speaker or a receiver. The speaker can be used for general purposes, such as playing multimedia or recording, and the receiver can be used for receiving incoming calls. The receiver can be implemented as separate from the speaker or as part of the speaker.

[0168] The display device 1560 can visually provide information to the outside of the electronic device 1501 (e.g., a user). The display device 1560 can include, for example, a display, a holographic device, or a projector, and control circuitry for controlling the corresponding one of the display, the holographic device, and the projector. The display device 1560 can include touch control circuitry or sensor circuitry (e.g., a pressure sensor) suitable for detecting a touch, and the sensor circuitry is suitable for measuring the intensity of the force caused by the touch.

[0169] The audio module 1570 can convert sound into an electrical signal and vice versa. The audio module 1570 can obtain sound via the input device 1550, or output sound via the sound output device 1555 directly (e.g., wired) or wirelessly coupled to the electronic device 1501 or a headset of an external electronic device 1502.

[0170] The sensor module 1576 can detect the operating state of the electronic device 1501 (e.g., power or temperature) or the environmental state outside the electronic device 1501 (e.g., the state of a user), and then generate an electrical signal or data value corresponding to the detected state. The sensor module 1576 can include, for example, a gesture sensor, a gyro sensor, an atmospheric pressure sensor, a magnetic sensor, an acceleration sensor, a grip sensor, a proximity sensor, a color sensor, an infrared (IR) sensor, a biometric sensor, a temperature sensor, a humidity sensor, or an illuminance sensor.

[0171] Interface 1577 may support one or more specified protocols for an electronic device 1501 that is to be used for direct (e.g., wired) or wireless coupling to an external electronic device 1502. Interface 1577 may include, for example, a high-definition multimedia interface (HDMI), a universal serial bus (USB) interface, a secure digital (SD) card interface, or an audio interface.

[0172] Connector 1578 may include a connector through which the electronic device 1501 may be physically connected to the external electronic device 1502. Connector 1578 may include, for example, an HDMI connector, a USB connector, an SD card connector, or an audio connector (e.g., a headset connector).

[0173] The tactile module 1579 may convert an electrical signal into a mechanical stimulus (e.g., vibration or movement) or an electrical stimulus, which may be recognized by the user via touch or kinesthesia. The tactile module 1579 may include, for example, a motor, a piezoelectric element, or an electrical stimulator.

[0174] The camera module 1580 may capture still images or moving images. The camera module 1580 may include one or more lenses, an image sensor, an image signal processor, or a flash. The power management module 1588 may manage the power supplied to the electronic device 1501. The power management module 1588 may be implemented as at least part of, for example, a power management integrated circuit (PMIC).

[0175] The battery 1589 may supply power to at least one component of the electronic device 1501. The battery 1589 may include, for example, a non-rechargeable primary battery, a rechargeable secondary battery, or a fuel cell.

[0176] The communication module 1590 can support establishing a direct (e.g., wired) communication channel or a wireless communication channel between the electronic device 1501 and an external electronic device (e.g., the electronic device 1502, the electronic device 1504, or the server 1508), and communicate via the established communication channel. The communication module 1590 can include one or more communication processors that can operate independently of the processor 1520 (e.g., the AP), and support direct (e.g., wired) communication or wireless communication. The communication module 1590 can include a wireless communication module 1592 (e.g., a cellular communication module, a short-range wireless communication module, or a global navigation satellite system (GNSS) communication module) or a wired communication module 1594 (e.g., a local area network (LAN) communication module or a power line communication (PLC) module). A corresponding one of these communication modules can communicate with the external electronic device via the first network 1598 (e.g., a short-range communication network, such as BluetoothTM, wireless-fidelity (Wi-Fi) Direct, or the Infrared Data Association (IrDA) standard) or the second network 1599 (e.g., a long-range communication network, such as a cellular network, the Internet, or a computer network (e.g., a LAN or a wide area network (WAN))). These various types of communication modules can be implemented as a single component (e.g., a single IC), or can be implemented as multiple components (e.g., multiple ICs) separated from each other. The wireless communication module 1592 can use the user information (e.g., the international mobile subscriber identity (IMSI)) stored in the user identity module 1596 to identify and authenticate the electronic device 1501 in a communication network (such as the first network 1598 or the second network 1599).

[0177] The antenna module 1597 can transmit signals or power to the outside of the electronic device 1501 (e.g., an external electronic device) or receive signals or power from the outside of the electronic device 1501. The antenna module 1597 can include one or more antennas, and can select at least one antenna suitable for the communication scheme used in the communication network, such as the first network 1598 or the second network 1599, from them, for example, by the communication module 1590 (e.g., the wireless communication module 1592). Signals or power can then be transmitted or received between the communication module 1590 and the external electronic device via the selected at least one antenna.

[0178] Commands or data can be transmitted or received between the electronic device 1501 and the external electronic device 1504 via the server 1508 coupled to the second network 1599. Each of the electronic device 1502 and the electronic device 1504 can be a device of the same type or a different type as the electronic device 1501. All or some of the operations to be performed at the electronic device 1501 can be performed at one or more of the external electronic device 1502, the external electronic device 1504, or the external electronic device 1508. For example, if the electronic device 1501 should perform a function or service automatically or in response to a request from a user or another device, then instead of or in addition to the electronic device 1501 performing the function or service, the electronic device 1501 can request one or more external electronic devices to perform at least part of the function or service. The one or more external electronic devices receiving the request can perform at least part of the requested function or service or additional functions or additional services related to the request and transmit the results of the performance to the electronic device 1501. The electronic device 1501 can provide the results as at least part of a reply to the request with or without further processing the results. For this purpose, technologies such as cloud computing, distributed computing, or client-server computing can be used.

[0179] Embodiments of the subject matter and the operations described in this specification can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware (including the structures disclosed in this specification and their structural equivalents), or in combinations of one or more of them. Embodiments of the subject matter described in this specification can be implemented as one or more computer programs, i.e., one or more modules of computer program instructions encoded on a computer storage medium for execution by, or to control the operation of, data processing apparatus. Alternatively or additionally, the program instructions can be encoded on an artificially generated propagated signal (e.g., a machine-generated electrical, optical, or electromagnetic signal) that is generated to encode information for transmission to a suitable receiver device for execution by the data processing apparatus. The computer storage medium can be or be included in a computer-readable storage device, a computer-readable storage substrate, a random or serial access memory array or device, or a combination of them. Further, when the computer storage medium is not a propagated signal, the computer storage medium can be a source or destination of computer program instructions encoded in an artificially generated propagated signal. The computer storage medium can also be one or more individual physical components or media (e.g., multiple CDs, disks, or other storage devices) or be included in one or more individual physical components or media. Additionally, the operations described in this specification can be implemented as operations performed by a data processing apparatus on data stored on one or more computer-readable storage devices or received from other sources.

[0180] Although this specification may contain many specific implementation details, the implementation details should not be construed as limiting the scope of any claimed subject matter, but rather as descriptions of features specific to particular embodiments. Certain features described in the context of individual embodiments in this specification may also be implemented in combination in a single embodiment. Conversely, the various features described in the context of a single embodiment may also be implemented separately in multiple embodiments or in any suitable sub-combination. Additionally, although the features may be described above as acting in certain combinations and even initially claimed as such, one or more features from the claimed combination may in some cases be deleted from the combination, and the claimed combination may be directed to a sub-combination or a variant of a sub-combination.

[0181] Similarly, although the operations are depicted in the drawings in a particular order, this should not be construed as requiring that the operations be performed in the particular order shown or in a sequential order, or that all of the illustrated operations be performed to achieve a desirable result. In some cases, multitasking and parallel processing may be advantageous. Additionally, the separation of the various system components in the embodiments described above should not be construed as requiring such separation in all embodiments, and it should be understood that the described program components and systems may generally be integrated together in a single software product or packaged into multiple software products.

[0182] Accordingly, specific embodiments of the subject matter have been described herein. Other embodiments are within the scope of the following claims. In some cases, the acts recited in the claims may be performed in a different order and still achieve a desirable result. Additionally, the processes depicted in the accompanying drawings do not necessarily require the particular order shown or a sequential order to achieve a desirable result. In certain implementations, multitasking and parallel processing may be advantageous.

[0183] As those skilled in the art will recognize, the novel concepts described herein can be modified and varied across a wide range of applications. Accordingly, the scope of the claimed subject matter should not be limited to any of the specific illustrative teachings discussed above, but is actually defined by the following claims.

[0184] 501, 503, 505, 1001, 1003, 1005, 1007, 1009, 1011, 1013, 1015, 1017, 1019, 1401, 1403, 1405, 1407, 1409, 1411, 1413: Steps 1500: Network environment 1501: Electronic device 1502, 1504: External electronic devices 1508: Server / External Electronic Device 1520: Processor 1521: Main Processor 1523: Auxiliary Processor 1530: Memory 1532: Volatile Memory 1534: Non-Volatile Memory 1540: Program 1542: Operating System 1544: Middleware 1546: Application Program 1550: Input Device 1555: Voice Output Device 1560: Display Device 1570: Audio Module 1576: Sensor Module 1577: Interface 1578: Connector 1579: Haptic Module 1580: Camera Module 1588: Power Management Module 1589: Battery 1590: Communication Module 1592: Wireless Communication Module 1594: Wired Communication Module 1596: User Identity Module 1597: Antenna Module 1598: First Network 1599: Second Network

Claims

1. A user equipment, comprising: transceiver; and a processor coupled to the transceiver, wherein the processor is configured to: determine whether the user equipment is operating in local mode or interleaved mode for sidelink (SL) communication, and in response to determining that the user equipment is operating in interleaved mode, decode the first stage SL control information (SCI) of the physical SL control channel (PSCCH) based on an interleaved mapping scheme, decode the second stage SCI of the physical SL shared channel (PSSCH) based on the decoded first stage SCI, and decode the PSSCH based on the decoded first stage SCI and the decoded second stage SCI, wherein the first stage SCI is the same for the local mode and the interleaved mode.

2. The user equipment as claimed in claim 1, wherein the plurality of resource blocks of the PSSCH are divided into K clusters, each of the K clusters comprising M resource blocks, and wherein M interleavings are defined, each of the M interleavings occupying one resource block from each of the K clusters.

3. The user equipment as claimed in claim 2, wherein the interleaving mapping scheme maps the PSCCH to the lowest resource block of one or more of the M interleavings.

4. The user equipment as claimed in claim 2, wherein the interleaving mapping scheme maps the PSCCH to the lowest and highest resource blocks of one or more of the M interleavings.

5. The user equipment as claimed in claim 2, wherein the interleaved mapping scheme maps the PSCCH in each of the M interleaved resource blocks, occupying only a portion of the symbols therein.

6. The user equipment as claimed in claim 2, wherein the interleaving mapping scheme maps the PSCCH onto all resource blocks of one or more of the M interleavings by multiplexing the PSCCH and the PSSCH within the plurality of resource blocks, wherein the PSSCH is mapped onto the M interleavings.

7. The user equipment as claimed in claim 1, wherein the interleaving mapping scheme is radio resource control (RRC) configured via a base station.

8. The user equipment as claimed in claim 1, wherein whether the user equipment operates in the local mode or the interleaved mode is controlled by radio resource control (RRC) configured by the base station.

9. The user equipment as claimed in claim 1, wherein the first-stage SCI indicates an interleaving index in the interleaving mode, and wherein the first-stage SCI indicates a sub-channel index in the local mode.

10. The user equipment as claimed in claim 1, wherein the processor is further configured to: receive at least one additional frequency interleaving assignment for PSSCH communication from the user transmitting equipment, and further decode the PSSCH based on the at least one additional frequency interleaving assignment.

11. A method performed by a user device, the method comprising: The system determines whether the user equipment is operating in local mode or interleaved mode for sidelink (SL) communication, and in response to determining that the user equipment is operating in interleaved mode, decodes the first stage SL control information (SCI) of the physical SL control channel (PSCCH) based on an interleaved mapping scheme, decodes the second stage SCI of the physical SL shared channel (PSSCH) based on the decoded first stage SCI, and decodes the PSSCH based on the decoded first stage SCI and the decoded second stage SCI, wherein the first stage SCI is the same for both local mode and interleaved mode.

12. The method of claim 11, wherein the plurality of resource blocks of the PSSCH are divided into K clusters, each of the K clusters comprising M resource blocks, and wherein M interleavings are defined, each of the M interleavings occupying one resource block from each of the K clusters.

13. The method of claim 12, wherein the interleaving mapping scheme maps the PSCCH to the lowest resource block of one or more of the M interleavings.

14. The method of claim 12, wherein the interleaving mapping scheme maps the PSCCH to the lowest and highest resource blocks of one or more of the M interleavings.

15. The method as described in claim 12, wherein the interleaved mapping scheme maps the PSCCH in each of the M interleaved resource blocks, occupying only a portion of the symbols therein.

16. The method of claim 12, wherein the interleaving mapping scheme maps the PSCCH onto all resource blocks of one or more of the M interleavings by multiplexing the PSCCH and the PSSCH within the plurality of resource blocks, wherein the PSSCH is mapped onto the M interleavings.

17. The method of claim 11 further includes receiving an instruction for the interleaving mapping scheme from the base station via Radio Resource Control (RRC).

18. The method of claim 11, wherein whether the user equipment operates in the local mode or the interleaved mode is controlled by radio resource control (RRC) configured by the base station.

19. The method of claim 11, wherein the first stage SCI indicates an interleaving index in the interleaving mode, and wherein the second stage SCI indicates a sub-channel index in the local mode.

20. The method as described in claim 11, further comprising: The user transmitting device receives at least one additional frequency interleaving assignment for PSSCH communication; And further decode the PSSCH based on the at least one additional frequency interleaving assignment.

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