User equipment and resource allocation method therefor

Abstract

A user equipment and a resource allocation method therefor are provided, the method comprising: performing monitoring over slots of a resource pool; excluding one or more sidelink resources from a set of candidate resources in the resource pool; and selecting one or more sidelink resources from the remaining set of candidate resources in the resource pool or from a resource selection window using a timing-based selection, thereby reducing the risk that pre-selected resources are taken over or reserved by other user equipments and / or improving the flexibility of sidelink control information (SCI) signaling to provide early indication / reservation of future sidelink resources, and subsequently improving overall system performance.

Description

[Technical field]

[0001] The present disclosure relates to the field of communication systems, and more particularly to a user equipment and a resource allocation method thereof that can provide good communication performance and high reliability. [Background technology]

[0002] In the development of new sidelink (SL) transmission systems based on the latest 5th generation-new radio (5G-NR) mobile technologies for direct vehicle-to-everything (V2X) wireless communication between user equipment (UE), one of the challenging tasks in the design is to support UEs to operate almost fully autonomously with minimal (pre-)configuration and possibly without any assistance from the mobile network. That is, SL UEs operating in this autonomous mode (known as Mode 2) should be able to detect and decode each other's SL UE's messages and independently select resources to transmit their own messages to other SL UEs with the required performance in terms of reliability and delay. However, when multiple UEs perform SL communication simultaneously and share the same radio carrier and Mode 2 resource pool, it is difficult to avoid transmission (Tx) collisions between UEs and maintain the required target performance. Furthermore, due to the autonomous nature of UE selection of SL resources in Mode 2, another UE may indicate / reserve or pre-empt one or more resources already pre-selected or announced by the original Tx-UE, forcing the original UE to find and reselect alternative resources. If this behavior occurs frequently in SL communication, the system may become unstable and unreliable, and packets of information messages may be unexpectedly lost and not received by other UEs.

[0003] Therefore, there is a need for a user equipment and a resource allocation method thereof that can provide good communication performance and high reliability. Summary of the Invention

[0004] The objective of the present disclosure is to propose a user equipment and a resource allocation method therefor, which improves the flexibility of the sidelink control information (SCI) signaling, reducing the risk that pre-selected resources are taken over or reserved by other user equipments and / or providing fast indication / reservation of future sidelink resources, and subsequently improving the overall system performance.

[0005] In a first aspect of the disclosure, a user equipment for resource allocation includes a memory, a transceiver, and a processor coupled to the memory and the transceiver, where the processor is configured to perform monitoring over slots of a resource pool, exclude one or more sidelink resources from a set of candidate resources in the resource pool, and select one or more sidelink resources using a timing based selection from a remaining set of candidate resources in the resource pool or a resource selection window.

[0006] In a second aspect of the disclosure, a method for resource allocation for a user equipment includes performing monitoring over slots of a resource pool, excluding one or more sidelink resources from a set of candidate resources in the resource pool, and selecting one or more sidelink resources from the remaining set of candidate resources in the resource pool or from a resource selection window using a timing based selection.

[0007] In a third aspect of the present disclosure, a non-transitory machine-readable storage medium has stored thereon instructions that, when executed by a computer, cause the computer to perform the method set forth above.

[0008] In a fourth aspect of the present disclosure, a terminal device includes a processor and a memory configured to store a computer program, the processor configured to execute the computer program stored in the memory to perform the method.

[0009] In a fifth aspect of the present disclosure, a base station includes a processor and a memory configured to store a computer program, the processor configured to execute the computer program stored in the memory to perform the above method.

[0010] In a sixth aspect of the present disclosure, the chip includes a processor configured to call and execute a computer program stored in a memory to cause an apparatus in which the chip is mounted to perform the above method.

[0011] In a seventh aspect of the present disclosure, a computer-readable storage medium having a computer program stored thereon causes a computer to execute the above method.

[0012] In an eighth aspect of the present disclosure, a computer program product comprises a computer program for causing a computer to carry out the above method.

[0013] In a ninth aspect of the present disclosure, a computer program causes a computer to carry out the above method.

[0014] In order to more clearly describe the embodiments of the present disclosure or the prior art, the following drawings described in the embodiments are briefly introduced. It is obvious that the drawings are only some embodiments of the present disclosure, and those skilled in the art can obtain other drawings based on these drawings without paying the premise. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a block diagram of a user equipment (UE) for resource allocation in a communication network system according to an embodiment of the present disclosure.

[0016] [Diagram 2] 1 is a flowchart illustrating a resource allocation method for a user equipment according to an embodiment of the present disclosure.

[0017] [Diagram 3] FIG. 2 illustrates an example of a time portion-based resource (re)selection scheme according to an embodiment of the present disclosure.

[0018] [Figure 4] FIG. 1 illustrates an example of a chain-based resource (re)selection scheme during resource re-evaluation according to an embodiment of the present disclosure.

[0019] [Diagram 5] FIG. 1 illustrates an example of a chain-based resource (re)selection scheme during resource pre-fetching according to an embodiment of the present disclosure.

[0020] [Figure 6] FIG. 1 is a block diagram of a wireless communication system according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] The embodiments of the present disclosure will be described in detail with reference to the following attached drawings, together with technical matters, structural features, objectives and effects achieved. Specifically, the terms in the embodiments of the present disclosure are merely for describing the objectives of specific embodiments, and are not intended to limit the present disclosure.

[0022] In some embodiments of the present disclosure, by enhancing the current resource selection mechanism, in order to save the processing power and complexity of the user equipment (UE), it is necessary and beneficial to avoid triggering the resource reselection process as much as possible and to avoid frequently changing the indicated resource when another UE tries to adopt the resource selection of the UE based on this indication (e.g., unicast and groupcast scenarios).Furthermore, in order to guarantee and improve the performance of SL communication and minimize the risk of transmission (Tx) collision between UEs, it is beneficial and essential to avoid other UEs from selecting the same resource by reserving the selected resource in advance or as early as possible.

[0023] The timing-based resource selection scheme according to some embodiments of the present disclosure aims to adapt the resource selection strategy of the Tx-UE to the assigned transmission profile (e.g., priority, packet delay budget (PDB)), reduce congestion on SL resources, minimize Tx collisions, and reduce the resource reselection probability. Other advantages of employing a timing-based resource selection method for initial transmission and / or retransmission of a transport block (TB) in New Radio (NR) sidelink communication include at least one of the following: 1. Minimizing the risk of pre-selected resources being taken over or reserved by other user equipments. 2. Improving the flexibility of sidelink control information (SCI) signaling to provide early indication / reservation of future resources, which in turn improves the overall system performance.

[0024] As shown in FIG. 1, in some embodiments, user equipment (UE) 10 and 20 for resource allocation in a communication network system 30 according to an embodiment of the present disclosure are provided. The communication network system 30 includes UE 10 and UE 20. UE 10 may include a memory 12, a transceiver 13, and a processor 11 coupled to the memory 12 and the transceiver 13. UE 20 may include a memory 22, a transceiver 23, and a processor 21 coupled to the memory 22 and the transceiver 23. The processor 11 or 21 may be configured to implement the proposed functions, procedures and / or methods described herein. A layer of a radio interface protocol may be implemented in the processor 11 or 21. The memory 12 or 22 is operably coupled to the processor 11 or 21 and stores various information for operating the processor 11 or 21. The transceiver 13 or 23 is operably coupled to the processor 11 or 21 and transmits and / or receives radio signals.

[0025] The processor 11 or 21 may include an application-specific integrated circuit (ASIC), other chipset, logic circuit, and / or data processing device. The memory 12 or 22 may include a read-only memory (ROM), a random access memory (RAM), a flash memory, a memory card, a storage medium, and / or other storage device. The transceiver 13 or 23 may include a baseband circuit for processing radio frequency signals. When an embodiment is implemented in software, the techniques described herein may be implemented with modules (e.g., procedures, functions, etc.) that perform the functions described herein. The modules may be stored in the memory 12 or 22 and executed by the processor 11 or 21. The memory 12 or 22 may be implemented within the processor 11 or 21 or external to the processor 11 or 21, provided that the memory 12 or 22 can be communicatively coupled to the processor 11 or 21 via various means known in the art.

[0026] The communication between the UEs relates to vehicle-to-vehicle (V2V), vehicle-to-pedestrian (V2P), and vehicle-to-infrastructure / network (V2I / N) communications, including sidelink technologies developed in 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) and New Radio (NR) Release 16 and later. The UEs communicate directly with each other over a sidelink interface, such as a PC5 interface. Some embodiments of the present disclosure relate to sidelink communication technologies in 3GPP NR Release 16 and later.

[0027] In some embodiments, the processor 11 is configured to perform monitoring over slots of a resource pool, exclude one or more sidelink resources from a set of candidate resources in the resource pool, and select one or more sidelink resources using a timing based selection from the remaining set of candidate resources in the resource pool or from the resource selection window, thereby reducing the risk that pre-selected resources are taken over or reserved by other user equipments and / or improving the flexibility of sidelink control information (SCI) signaling to provide early indication / reservation of future sidelink resources, and subsequently improving the overall system performance.

[0028] In some embodiments, the resource pool is configured by the network or pre-configured. In some embodiments, the resource pool includes a selection / mode 2 resource pool for sidelink transmissions. In some embodiments, monitoring the slots of the resource pool is performed by decoding the physical sidelink control channel (PSCCH) and measuring the reference signal received power (RSRP) during a sensing window of the resource pool. In some embodiments, excluding one or more sidelink resources from the candidate resource set is based on one or more information regarding L1 priority, time and frequency resource allocation, and reservation periodicity from the sidelink control information (SCI), and the RSRP threshold.

[0029] In some embodiments, the selection of one or more sidelink resources using a timing based selection from the remaining candidate resource set or resource selection window is based on at least one of a time portion based selection scheme that prioritizes or highly ranks one or more time portions in the remaining candidate resource set or resource selection window for selection and a chain based selection scheme that identifies one or more slot regions for selection within a time constraint of a maximum time gap from the previous and / or next sidelink resource.

[0030] In some embodiments, in a time portion based selection scheme, one or more sidelink resources are randomly selected from one or more time portions in the remaining candidate resource set or resource selection window. In some embodiments, in a time portion based selection scheme, one or more time portions in the remaining candidate resource set or resource selection window are

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[0031] In some embodiments, in a time-portion based selection scheme, an initial time portion of the remaining candidate resource set or resource selection window is used for resource selection, the initial time portion being the first X% of the time (where X is predefined or configured by the network or preconfigured) of the remaining candidate resource set or resource selection window, or the first Z slots (where Z is predefined or configured by the network or preconfigured) in the remaining candidate resource set or resource selection window, or the first Y sidelink resources (where Y is predefined or configured by the network or preconfigured) from the remaining candidate resource set or resource selection window, or the first 10 sidelink resources (where Y is predefined or configured by the network or preconfigured) of the remaining candidate resource set or resource selection window. 2、min -T1) (where T 2、min is an RRC configuration parameter that sets the minimum resource selection time window for the associated TB with the preference value. In some embodiments, X may be equal to 5, 10 or 20. In some embodiments, Z may be equal to 1, 2, 5 or 10. In some embodiments, Y may be equal to 1, 2, 3, 5 or 10.

[0032] In some embodiments, in the chain-based selection scheme, one or more sidelink resources are randomly selected from one or more slot regions. In some embodiments, in the chain-based selection scheme, one or more slot regions in the remaining candidate resource set or resource selection window are identified based on at least one of: defining a lower time limit of a slot region by a time gap before the time slot of the next sidelink resource and defining an upper time limit of a slot region by a time gap after the time slot of the previous sidelink resource; defining lower and upper time limits of a slot region by time gaps before and after the time slot of the next sidelink resource, respectively; and defining an upper time limit of a slot region by a time gap after the time slot of the previous resource. In some embodiments, the maximum of all time gaps is less than or equal to 32 slots. In some embodiments, if there are no available / candidate sidelink resources between the lower and upper time limits, the processor reselects alternative sidelink resources including the previous and / or next resource. In some embodiments, the reselected alternative sidelink resources satisfy the 32 slot time restriction between any two consecutive sidelink resources.

[0033] 2 illustrates a resource allocation method 200 for a UE according to an embodiment of the present disclosure. In some embodiments, the method 200 includes block 202 performing monitoring over slots of a resource pool, block 204 excluding one or more sidelink resources from a set of candidate resources in the resource pool, and block 206 selecting one or more sidelink resources from the remaining set of candidate resources or resource selection window in the resource pool using a timing based selection, thereby reducing the risk that pre-selected resources are taken over or reserved by other UEs and / or improving the flexibility of sidelink control information (SCI) signaling to provide early indication / reservation of future sidelink resources, which in turn improves the overall system performance.

[0034] In some embodiments, the resource pool is configured by the network or pre-configured. In some embodiments, the resource pool includes a selection / mode 2 resource pool for sidelink transmissions. In some embodiments, monitoring the slots of the resource pool is performed by decoding the Physical Sidelink Control Channel (PSCCH) and measuring the Reference Signal Received Power (RSRP) during a sensing window of the resource pool. In some embodiments, excluding one or more sidelink resources from the candidate resource set is based on one or more information regarding L1 priority, time and frequency resource allocation, and reservation periodicity from the Sidelink Control Information (SCI), and an RSRP threshold.

[0035] In some embodiments, the selection of one or more sidelink resources using a timing based selection from the remaining candidate resource set or resource selection window is based on at least one of a time portion based selection scheme that prioritizes or highly ranks one or more time portions in the remaining candidate resource set or resource selection window for selection and a chain based selection scheme that identifies one or more slot regions for selection within a time constraint of a maximum time gap from the previous and / or next sidelink resource.

[0036] In some embodiments, in a time portion based selection scheme, one or more sidelink resources are randomly selected from one or more time portions in the remaining candidate resource set or resource selection window. In some embodiments, in a time portion based selection scheme, one or more time portions in the remaining candidate resource set or resource selection window are

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[0037] In some embodiments, in a time portion based selection scheme, an initial time portion of the remaining candidate resource set or resource selection window is used for resource selection, the initial time portion being the first X% of the time in the remaining candidate resource set or resource selection window (where X is predefined or configured by the network or preconfigured), or the first Z slots in the remaining candidate resource set or resource selection window (where Z is predefined or configured by the network or preconfigured), the first Y sidelink resources from the remaining candidate resource set or resource selection window (where Y is predefined or configured by the network or preconfigured), or the first 10 ... T is predefined or configured by the network or preconfigured). 2、min -T1) (where T 2、min is an RRC configuration parameter that sets the minimum resource selection time window for the associated TB with the preference value. In some embodiments, X may be equal to 5, 10 or 20. In some embodiments, Z may be equal to 1, 2, 5 or 10. In some embodiments, Y may be equal to 1, 2, 3, 5 or 10.

[0038] In some embodiments, in the chain-based selection scheme, one or more sidelink resources are randomly selected from one or more slot regions. In some embodiments, in the chain-based selection scheme, one or more slot regions in the remaining candidate resource set or resource selection window are identified based on at least one of: defining a lower time limit of a slot region by a time gap before the time slot of the next sidelink resource and defining an upper time limit of a slot region by a time gap after the time slot of the previous sidelink resource, or defining a lower time limit and an upper time limit of a slot region by a time gap before and after the time slot of the next sidelink resource, respectively, or defining an upper time limit of a slot region by a time gap after the time slot of the previous resource. In some embodiments, the maximum of all time gaps is less than or equal to 32 slots. In some embodiments, if there is no available / candidate sidelink resource between the lower time limit and the upper time limit, the processor reselects alternative sidelink resources including the previous resource and / or the next resource. In some embodiments, the reselected alternative sidelink resources satisfy the 32 slot time restriction between any two consecutive sidelink resources.

[0039] 3 is a diagram illustrating an example of a time portion based resource (re)selection scheme according to an embodiment of the present disclosure. As shown in FIG. 3, in some embodiments, the UE determines a set of slots representing a Resource Selection Window (RSW) 301 between n+T1 302 and n+T2 303 for the (pre-)configured sidelink selection / mode 2 resource pool after the resource allocation procedure is triggered at time n 304, and determines a candidate resource set S for the RSW that includes all applicable sidelink (SL) resources with suitable subchannel sizes for transmitting the Physical Sidelink Shared Channel (PSSCH) and the PSCCH. A All applicable SL resources are set up / initialized in the candidate resource set S 307, which includes all the shaded boxes 305 and the transparent boxes 306. AThe UE then classifies all SL resources (transparent boxes) that are indicated / reserved by SCIs received during the sensing window and whose associated measured RSRP levels are higher than the corresponding RSRP thresholds into a candidate resource set S A 307. These reserved resources / transparent boxes are shown as 306. The shaded box 305 then shows the remaining candidate resources (here in the set S′ A (denoted as

[0040] Currently, the existing resource selection procedures defined by 3GPP for LTE sidelink mode 4 and NR sidelink mode 2 operation mainly focus on the set S' A This scheme consists of randomly selecting one or more SL resources from the remaining candidate resources in the RSW. However, as mentioned above, the result of this random selection may be a set of SL resources that are concentrated only in a small time portion / area of ​​the RSW (e.g., the middle or last part of the RSW) and cause these parts of the resource pool to be more congested than other parts. Furthermore, this random selection scheme has a high risk that the selected, further reserved resources will be indicated or announced or pre-empted by another UE if the time gap between the resource selection and the actual transmission is wide. Furthermore, if the randomly selected resources are not within a signaling time limit (e.g., 32 slots) from the previous and / or next already pre-selected resources, the randomly selected resources cannot be signaled together in the same SCI or previous SCIs, so future resources cannot be pre-reserved to minimize Tx collisions. To mitigate these issues, the following resource selection scheme is proposed.

[0041] Please note that the two resource selection schemes proposed below are not competing alternatives and may be applied separately or in combination with each other depending on the resource (re)selection scenario. The suitable scenarios or user cases for each scheme are detailed in the respective sections.

[0042] First aspect (time portion based resource (re)selection):

[0043] For a time fraction based resource (re)selection scheme, one or more time fractions in the remaining candidate resource set or RSW can be identified based on any of the following methods: Advantages: Using a time fraction based scheme spreads resource utilization, reduces resource congestion, and minimizes transmission collisions. Furthermore, it reduces the possibility that the preselected resource will be taken over or preempted by another UE.

[0044] In some embodiments, the proposed first resource (re)selection scheme is a time portion based method, which selects either the duration of the RSW (T2-T1) or the remaining candidate resource set (S' A ) is configured into one or more time portions, and / or the Tx-UE may use RSW(T2-T1) or the remaining candidate resource set (S' A ) and select SL resources from the specific time portions for transmission. Selecting resources from a period belonging to a specific time portion (e.g., first / middle / last portion) reduces the possibility of Tx collisions due to resource congestion, meets the short packet delay budget of the TB, and / or minimizes the risk of the pre-selected resources being taken over or reserved by another UE.

[0045] In some embodiments, the duration of the RSW or the remaining candidate resource set (S′ A ) into one or more time portions, the period is divided based on at least one of the following:

[0046] 1.

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[0049] RSW or the remaining candidate resource set S' AIn addition to the above mentioned usage scenarios of splitting the UE 1 into the first, middle and last time portions to align with SCI signaling, this time portion based resource selection also serves the following uses: For example, the first time portion 308 serves to select resources for the initial transmission of TB to reduce the possibility that the selected resources are preempted or reserved by another UE and to reserve retransmission resources early; the middle time portion 309 serves to select both blind based retransmission resources and HARQ feedback based retransmission resources; and both the middle time portion 309 and the last time portion 310 serve to select retransmission resources to reduce resource congestion and minimize the possibility of Tx collision.

[0050] In some cases, the Tx-UE may select the RSW 301 or the remaining candidate resource set (S′ A ) may be identified as more important / critical or suitable / relevant for (re)selecting SL resources. For example, a high priority TB is often associated with a short delay requirement (i.e., a small PDB). To meet the stringent delay requirement and high transmission reliability guarantee for the high priority TB (e.g., to allow sufficient resources / opportunities for retransmission), the Tx-UE identifies the first time portion after resource selection is triggered and selects one or more SL resources from the first time portion for the initial transmission and retransmission (if necessary) of the TB. On the other hand, if the packet delay requirement of the TB is not so stringent or is relatively relaxed, the Tx-UE may try to (re)select resources from a time portion with less resource congestion. Usually, the early time portions are often more congested than other time portions, since TBs with small PDBs need to be transmitted as soon as possible. Thus, for example, if the measured channel busy ratio (CBR) or channel occupancy ratio (CR) of a time portion is less than a certain M%, where M may be 60, 50 or less, the Tx-UE may select RSW or the remaining candidate resource set S′.A Alternatively, the Tx-UE may avoid (re)selecting resources from time portions where the CBR or CR is higher than M%.

[0051] In some embodiments, after a resource (re)selection is triggered, in order to perform at least the initial transmission of TB as soon as possible, the RSW or the remaining candidate resource set (S′ A The first time portion in may be defined or (pre-)configured in at least one of the following ways (see diagram 300 in FIG. 3):

[0052] 1. RSW (Set S A ) or the remaining candidate resource set (S' A ) 311 for the first X% of time (where X may be 5, 10, 20). Alternatively, this may be the number of slots (e.g., RSW or remaining candidate resource set S' A (where Z may be 1, 2, 5 or 10).

[0053] 2. RSW (Set S A ) or the remaining candidate resource set (S' A ) 311 the first Y resources (for example, Y can be 1, 2, 3, 5 or 10).

[0054] 3. Window (T 2、min -T1)312 (where (n+T 2、min )313 in T 2、min is an RRC (pre)configured parameter that sets the minimum resource selection time window for the associated TB with priority value p).

[0055] If there are two or more candidate resources in the first time portion, the Tx-UE randomly selects one or more resources for the initial transmission and / or retransmission of the TB. For example, the RSW 301 or the remaining candidate resource set (S′ A) is identified / configured as the time portion during which the Tx-UE can select the first transmission resource (for either the initial transmission or a retransmission of the TB), and if there are multiple candidate resources available in the first slots 314 and 315, the Tx-UE randomly selects one of these two / available resources.

[0056] Second aspect (Chain-based resource (re)selection and reservation):

[0057] In case of a chain-based resource (re)selection scheme, one or more slot regions in the remaining candidate resource set or RSW are identified based on one of the following methods: Advantages: For the purpose of fast / chain-based reservation to reduce Tx collisions in SL communication, using a chain-based scheme ensures that a newly selected SL resource can signal / reserve the next selected resource on the same SCI and / or that a newly selected SL resource can signal / reserve by a previously selected resource on the same SCI.

[0058] In addition to the above time portion based scheme used by SL transmitting UEs to (re)select resources for initial and / or retransmission of TB, in some embodiments, another resource (re)selection scheme that the Tx-UE can further adopt is a chain based method that ensures that the newly selected resource can be indicated by at least one previous SCI and / or that the next preselected or already announced / signaled resource can be indicated by the newly (re)selected resource. To achieve this early / chain based reservation, the resource selection or substitution can comply with the criteria that the newly selected resource is in a slot from the RSW and within a maximum time gap from the previous and / or next already preselected or announced / signaled resource. That is, the time gap can be less than or equal to 32 slots, because 32 slots is the maximum time length currently supported by the time resource allocation parameters of SCI formats 0-1. This chain based resource (re)selection scheme is therefore ideally suited for the reselection or reevaluation of SL resources that have been preempted or announced / signaled by another UE before the actual SL transmission.

[0059] As part of the resource allocation mechanism for sidelink mode 2 currently defined in 3GPP, the Tx-UE shall perform a re-evaluation of SL resources that were previously selected but not yet announced / signaled by the Tx-UE (these resources are also commonly known as pre-selected resources) and shall allocate the SL resources if this resource becomes unavailable due to announcement / reservation of any of the pre-selected resources from another UE (e.g., from the remaining candidate resource set S' A However, reselection of a preselected resource (finding an alternative resource) may be delayed by the RSW or the remaining candidate resource set (S' A), this process does not guarantee that the newly selected resource can be signaled / reserved by the previous SCI or that the newly selected resource can signal / reserve the next pre-selected resource on the same SCI.

[0060] FIG. 4 illustrates an example of a chain-based resource (re)selection scheme during resource re-evaluation according to an embodiment of the present disclosure. Referring to diagram 400 of FIG. 4, a diagram illustrating an example of a proposed chain-based resource (re)selection scheme is shown for a resource reselection scenario during re-evaluation of pre-selected SL resources. As shown in FIG. 4, in some embodiments, SL resources R1 401, R2 402 and R3 403 are resources that have already been pre-selected by the Tx-UE but have not yet been announced / signaled to other UEs. Before transmitting PSCCH / PSSCH using pre-selected SL resource R1 401 and announcing / signaling SL resources R2 and R3 for the first time via SCI format 0-1 of SL resource R1, the Tx-UE detects an SCI transmission at 404 reserving or partially reserving the same SL resource R2 402 from another UE. Based on the detection of the reserved SCI at 404, the Tx-UE triggers a resource re-evaluation process at slot n 405 for all pre-selected SL resources R1, R2 and R3 before the planned SL PSCCH / PSSCH transmission on SL resource R1 401 to determine whether those resources are still included in the remaining candidate resource set (S' A ) due to a reservation from another UE. A ), and Tx-UE needs to perform a new SL resource reselection to replace SL resource R2 402. For the proposed chain-based resource reselection scheme, the remaining candidate resource set (S' A ), the Tx-UE first determines a suitable time region in which it can perform reselection of the SL resource R2.

[0061] In some embodiments, a time upper bound 407 in the time domain (R1+32 slots) may be established to ensure that the new / alternative SL resource for R2 is within at least 32 slots of the previous preselected resource such that the newly reselected SL resource R2 can still be reserved / signaled by the PSCCH transmitted on SL resource R1 401. Similarly, a time lower bound 406 in the time domain (R3-32 slots) may be established to ensure that the new / alternative resource for R2 is within at least 32 slots of the next preselected resource such that the PSCCH transmitted from the newly reselected SL resource R2 can still reserve / signal the next preselected SL resource R3 403. Thus, reselection of SL resource R2 402 may be performed within an overlap time region 408 between the time lower bound 406 and the time upper bound 407. If the time gap / distance separation between SL resources R1 401 and R3 403 is less than or equal to 32 slots (slots may be physical or logical slots), the reselection / alternate resource for SL resource R2 402 may be in any of the unused slots in the resource chain. Otherwise, the reselection / alternate SL resource for R2 402 may be limited within a lower time limit 406 and an upper time limit 407, as described above and shown in FIG. 400. If there is no available / candidate resource within the time limit 408, the Tx-UE reselects another pre-selected SL resource (R1 or R3) along with R2 402 such that the newly selected alternative resource still meets the 32 slot time limit of the chain selection / reservation. For example, reselect both SL resources R1 and R2 such that the new SL resource R2 is within 32 slots of SL resource R3 and the new SL resource R1 is within 32 slots of the new SL resource R2.

[0062] FIG. 5 illustrates an example of a chain-based resource (re)selection scheme during resource pre-emption according to an embodiment of the present disclosure. Referring to diagram 500 of FIG. 5, a diagram illustrating an example of the proposed chain-based resource (re)selection scheme is shown for a resource reselection scenario with SL resource pre-emption. As shown in FIG. 5, in some embodiments, SL resources R1 501, R2 502 and R3 503 are SL resources selected by Tx-UE for PSCCH / PSSCH transmission. During PSCCH transmission on SL resource R1 501, SL resources R2 502 and R3 503 are announced / signaled with the same SCI format 0-1 for future reservation. After PSCCH transmission on SL resource R1 501, Tx-UE detects 504 an SCI with a higher L1 priority than the transmitted SL resource R1 itself and pre-empts / reserves (fully or partially) the same SL resource R2 502 from another UE. Based on detection of the preempted SCI at 504, the Tx-UE triggers a resource reselection procedure at slot n 505 prior to the planned PSCCH / PSSCH transmission on SL resource R2 502 to reselect a new / alternative resource for the preempted SL resource R2 502.

[0063] In some embodiments, for the proposed chain-based resource reselection scheme, the remaining candidate resource set (S′ A), the Tx-UE first determines a suitable time region where reselection of SL resource R2 can be performed. Since the timing of the resource reselection trigger at time n 505 is after the PSCCH / PSSCH transmission slot of SL resource R1 (i.e., R1 is an already used SL resource in the past), the slot timing of the new SL resource R2 does not need to be within 32 slots from SL resource R1 501 due to chain reservation. However, for the proposed chain-based resource reselection scheme, the newly reselected SL resource R2 may still be within 32 slots from the already announced / signaled SL resource R3 503 to ensure that the new / alternative resource of SL resource R2 can signal / reserve or be signaled / reserved by SL resource R3 503. To achieve this, a time domain for reselection of R2 508 may be established by the Tx-UE with a lower time bound (R3-32 slots) at 506 and an upper time bound (R3+32 slots) at 507. If there are no remaining candidate resources available within the time bound 508, the Tx-UE reselects the other already announced / signaled SL resource R3 503 together with R2 502 such that the newly selected alternative resource still meets the 32 slot time limit of chain selection / reservation. For example, both SL resources R2 and R3 are reselected and the new SL resource R2 and the new SL resource R3 are within 32 slots of each other.

[0064] In summary, in some embodiments, in the present disclosure of an inventive method of radio resource (re)selection intended for use in new radio sidelink (NR-SL) communications, a transmitting user equipment (Tx-UE) selects one or more SL resources to transmit a SL transport block (TB) according to a transmission time portion in a resource selection window (RSW) and / or based on time limits associated with adjacent resources. By spreading the resource selection over time, prioritizing certain time portions in the RSW for resource selection, and / or following timing selection restrictions, the proposed inventive method minimizes the risk of transmission (Tx) collisions and the risk of pre-selected resources being reserved or pre-empted by another UE, while improving overall system performance due to the use of indication / pre-reservation of future SL resources in sidelink control information (SCI) signaling.

[0065] In some embodiments, for the proposed resource (re)selection scheme, the Tx-UE first receives a network configuration or gets a pre-configured signaling including information of the SL "selected" (known as Mode 2) transmission resource pool, and performs SL resource sensing / monitoring of slots belonging to the (pre-)configured resource pool within a sensing window, the resource sensing / monitoring operation includes decoding the Physical Sidelink Control Channel (PSCCH) to obtain one or more time and frequency resource allocations for current and future intended / reserved resources, resource reservation periods (P rsvp_RX ), and the priority (prio) from the received SCI format 0-1 (first-stage SCI) RX ) and measuring the RSRP level (based on PSCCH-RSRP or PSSCH-RSRP) of SCI formats 0-1 received in these slots.

[0066] Commercial interests of some embodiments are as follows: 1. Provides more reliable and faster NR sidelink radio transmission performance by reducing resource congestion and transmission collisions. 2. Reduces the risk of resource reselection and terminal processing power consumption by fast selection and chain reservation. 3. Provides superior communication performance. 4. Provides high reliability. 5. Some embodiments of the present disclosure are used by 5G-NR chipset vendors, V2X communication system development vendors, automobile manufacturers including cars, trains, trucks, buses, bicycles, moto-bikes, helmets, etc., drones (unmanned aerial vehicles), smartphone manufacturers, communication devices for public safety applications, and AR / VR device manufacturers for games, meetings / seminars, and education applications. Some embodiments of the present disclosure are a combination of "technology / process" that can be adopted in 3GPP specifications to create an end product.

[0067] FIG. 6 is a block diagram of an exemplary wireless communication system 700 according to an embodiment of the present disclosure. The embodiments described herein may be implemented in a system using any suitably configured hardware and / or software. FIG. 6 illustrates system 700 including at least radio frequency (RF) circuitry 710, baseband circuitry 720, application circuitry 730, memory / storage 740, display 750, camera 760, sensor 770, and input / output (I / O) interface 780 coupled together as shown.

[0068] The application circuitry 730 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processors may include any combination of general-purpose processors and special-purpose processors, such as graphics processors and application processors. The processors may be coupled to memory / storage and configured to execute instructions stored in the memory / storage to enable various applications and / or operating systems to run on the system.

[0069] The baseband circuitry 720 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor may include a baseband processor. The baseband circuitry may process various radio control functions that enable communication with one or more wireless networks via RF circuitry. The radio control functions may include, but are not limited to, signal modulation, encoding, decoding, and radio frequency shifting. In some embodiments, the baseband circuitry may provide communication in accordance with one or more wireless technologies. For example, in some embodiments, the baseband circuitry may support communication with an evolved universal terrestrial radio access network (EUTRAN) and / or other wireless metropolitan area networks (WMANs), wireless local area networks (WLANs), wireless personal area networks (WPANs). In embodiments in which the baseband circuitry is configured to support wireless communication of one or more wireless protocols, it may be referred to as a multimode baseband circuit.

[0070] In various embodiments, the baseband circuitry 720 may include circuitry that operates on signals that are not strictly considered to be at baseband frequencies. For example, in some embodiments, the baseband circuitry may include circuitry that operates on signals having intermediate frequencies between baseband frequencies and radio frequencies.

[0071] The RF circuitry 710 may enable communication with a wireless network using modulated electromagnetic radiation over a non-solid medium. In various embodiments, the RF circuitry may include switches, filters, amplifiers, etc. to facilitate communication with the wireless network.

[0072] In various embodiments, RF circuitry 710 may include circuitry that operates on signals that are not strictly considered to be at radio frequencies. For example, in some embodiments, RF circuitry may include circuitry that operates on signals having intermediate frequencies between baseband frequencies and radio frequencies.

[0073] In various embodiments, the transmit side circuitry, control circuitry, or receive side circuitry described above for a user equipment, eNB, or gNB may be embodied in all or part of one or more of RF circuitry, baseband circuitry, and / or application circuitry. As used herein, "circuitry" refers to, is a part of, or includes application specific integrated circuits (ASICs), electronic circuits, processors (shared, dedicated, or group), and / or memories (shared, dedicated, or group) that execute one or more software or firmware programs, combinatorial logic circuits, and / or other suitable hardware components that provide the functionality described above. In some embodiments, electronic circuitry may be implemented in one or more software or firmware modules, or functionality associated with a circuitry may be implemented by one or more software or firmware modules.

[0074] In some embodiments, some or all of the baseband circuitry, application circuitry and / or memory / storage components may be implemented together on a system on a chip (SoC).

[0075] Memory / storage 740 may be used, for example, to load and store data and / or instructions for the system. The memory / storage of one embodiment may include any combination of suitable volatile memory, such as dynamic random access memory (DRAM), and / or non-volatile memory, such as flash memory.

[0076] In various embodiments, I / O interface 780 may include one or more user interfaces designed to enable user interaction with the system and / or peripheral component interfaces designed to enable peripheral component interaction with the system. User interfaces may include, but are not limited to, a physical keyboard or keypad, a touchpad, a speaker, a microphone, etc. Peripheral component interfaces may include, but are not limited to, a non-volatile memory port, a Universal Serial Bus (USB) port, an audio jack, and a power interface.

[0077] In various embodiments, the sensors 770 may include one or more sensing devices that determine environmental conditions and / or location information for the system. In some embodiments, the sensors may include, but are not limited to, gyro sensors, accelerometers, proximity sensors, ambient light sensors, and a positioning unit. The positioning unit may also be part of or interact with baseband and / or RF circuitry that communicates with components of a positioning network, such as Global Positioning System (GPS) satellites.

[0078] In various embodiments, the display 750 may include displays such as liquid crystal displays and touch screen displays. In various embodiments, the system 700 may be a mobile computing device, such as, but not limited to, a laptop computing device, a tablet computing device, a netbook, an ultrabook, a smartphone, AR / VR glasses, etc. In various embodiments, the system may have more or fewer components and / or a different architecture. Where appropriate, the methods described herein may be implemented as a computer program. The computer program may be stored on a storage medium, such as a non-transitory recording medium.

[0079] Those skilled in the art can understand that each of the units, algorithms and steps described and disclosed in the embodiments of the present disclosure can be realized using electronic hardware or a combination of computer software and electronic hardware. Whether a function is performed by hardware or software depends on the application conditions and design requirements of the technical solution.

[0080] Those skilled in the art can use different methods to realize the functions for each specific application, but such realization should not exceed the scope of the present disclosure. Those skilled in the art can understand that the operation processes of the above-mentioned systems, devices and units are basically the same, so that reference can be made to the operation processes of the systems, devices and units in the above-mentioned embodiments. For convenience and simplicity of explanation, these operation processes will not be described in detail.

[0081] It is understood that the disclosed system, device, and method in the embodiments of the present disclosure can be realized in other ways. The above-mentioned embodiments are only examples. The division of units is only based on logical functions, but other divisions exist in the realization. A plurality of units or parts may be combined or integrated into other systems. Some features may be omitted or skipped. Meanwhile, the shown or discussed mutual couplings, direct couplings, or communication couplings may operate indirectly or communicatively through some ports, devices, or units in an electrical, mechanical, or other form.

[0082] The units described as separate components may or may not be physically separated. The display unit may or may not be a physical unit, i.e., it may be in one place or distributed across multiple network units. Some or all of the units may be used according to the purpose of the embodiment. Furthermore, each functional unit in each embodiment may be integrated into one processing unit, may be physically independent, or two or more units may be integrated into one processing unit.

[0083] When the software functional unit is realized as a product and used and sold, it can be stored in a computer-readable storage medium. Based on this understanding, the technical proposal proposed in the present disclosure can be essentially or partially realized in the form of a software product. Alternatively, some of the technical proposals useful in the prior art can be realized in the form of a software product. A computer software product includes a plurality of instructions stored in a storage medium, which causes a computing device (e.g., a personal computer, a server, or a network device) to execute all or some of the steps disclosed in the embodiments of the present disclosure. The storage medium includes a USB disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a floppy disk, or other types of media capable of storing program code.

[0084] While the present disclosure has been described in connection with what are considered to be the most practical and preferred embodiments, it is understood that the present disclosure is not limited to the disclosed embodiments, but is intended to cover various configurations that may be made without departing from the broadest interpretation of the scope of the appended claims.

Claims

1. Memory, A transceiver; a processor coupled to the memory and the transceiver, The processor performs monitoring for slots of a resource pool; excluding one or more sidelink resources from a set of candidate resources in the resource pool; configured to select one or more sidelink resources using a timing based selection from a set of remaining candidate resources in the resource pool; and selecting one or more sidelink resources using a timing based selection from a remaining candidate resource set in the resource pool comprises the user equipment identifying a plurality of time portions in the remaining candidate resource set and the user equipment selecting one or more sidelink resources from the plurality of time portions in the remaining candidate resource set. selecting one or more of the sidelink resources using a timing based selection from the remaining set of candidate resources comprises: A user equipment for resource allocation based on a chain based selection scheme that identifies for selection one or more slot regions within a time constraint of a maximum time gap from a previous sidelink resource and / or a next sidelink resource.

2. The user equipment of claim 1 , wherein the resource pool is network configured or pre-configured.

3. 3. The user equipment of claim 1 or 2, wherein the resource pool comprises a resource pool of a mode 2 selection for sidelink transmissions.

4. 4. The user equipment of claim 1, wherein monitoring of the slots of the resource pool is performed by decoding a Physical Sidelink Control Channel (PSCCH) and measuring a Reference Signal Received Power (RSRP) during a sensing window of the resource pool.

5. The UE of any one of claims 1 to 4, wherein excluding one or more sidelink resources from the candidate resource set is based on one or more information on L1 priority, time and frequency resource allocation, and reservation periodicity from Sidelink Control Information (SCI), and an RSRP threshold.

6. 2. The user equipment of claim 1, wherein the maximum of all time gaps is less than or equal to 32 slots.

7. performing monitoring for slots of a resource pool; removing one or more sidelink resources from a set of candidate resources in the resource pool; selecting one or more sidelink resources from a set of remaining candidate resources in the resource pool using a timing based selection, and selecting one or more sidelink resources using a timing based selection from a remaining candidate resource set in the resource pool comprises the user equipment identifying a plurality of time portions in the remaining candidate resource set and the user equipment selecting one or more sidelink resources from the plurality of time portions in the remaining candidate resource set. selecting one or more of the sidelink resources using a timing based selection from the remaining set of candidate resources comprises: A method for resource allocation for a user equipment based on a chain-based selection scheme that identifies for selection one or more slot regions within a time constraint of a maximum time gap from a previous sidelink resource and / or a next sidelink resource.

8. The method of claim 7 , wherein the resource pool is network configured or pre-configured.

9. 9. The method of claim 7 or 8, wherein the resource pool comprises a selected / mode 2 resource pool for sidelink transmissions.

10. 10. The method according to claim 7, wherein monitoring the slots of the resource pool is performed by decoding a Physical Sidelink Control Channel (PSCCH) and measuring a Reference Signal Received Power (RSRP) during a sensing window of the resource pool.

11. The method according to any one of claims 7 to 10, wherein excluding one or more sidelink resources from the candidate resource set is based on one or more information on L1 priority, time and frequency resource allocation, and reservation periodicity from sidelink control information (SCI), and an RSRP threshold.

12. 8. The method of claim 7, wherein the maximum of all time gaps is less than or equal to 32 slots.

13. A non-transitory machine-readable storage medium having stored thereon instructions which, when executed by a computer, cause the computer to perform the method of any one of claims 7 to 12.

14. A chip comprising a processor configured to cause a device in which the chip is mounted to execute the method according to any one of claims 7 to 12 by calling and executing a computer program stored in a memory.

15. A computer-readable storage medium having stored thereon a computer program for causing a computer to execute the method according to any one of claims 7 to 12.

16. A computer program causing a computer to carry out the method according to any one of claims 7 to 12.

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