Method and Device for Resource Allocation in V2X Communication

Abstract

Embodiments of the present disclosure relate to methods and devices for resource allocation in vehicle-to-everything (V2X) communication. According to an embodiment of the present disclosure, a method may include: determining resource allocation information indicating at least one set of resources for a set of transport blocks; and transmitting the determined resource allocation information. Each set of resources is associated with a transport block in the set of transport blocks to be transmitted on a sidelink. Each set of resources may include: a plurality of sidelink transmission resources, each sidelink transmission resource being configured to carry a sidelink transmission of the transport block; a plurality of sidelink feedback resources, each sidelink feedback resource being configured to carry sidelink feedback information in response to the sidelink transmission of the transport block; and a plurality of uplink feedback resources, at least one of the plurality of uplink feedback resources being configured to carry uplink feedback information in response to the sidelink transmission of the transport block only if the sidelink feedback information indicates that the transport block has been successfully decoded.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to wireless communication technologies, and more particularly, to methods and apparatuses for resource allocation in New Radio (NR) for supporting Vehicle-to-Everything (V2X) communication. Background Art

[0002] In a wireless communication system, a User Equipment (UE), such as a mobile device, may communicate with another UE via a data path supported by a carrier network, such as a cellular or Wi-Fi network infrastructure. The data path supported by the carrier network may include a Base Station (BS) and multiple gateways.

[0003] In the case where two UEs are relatively close to each other, a radio link or Sidelink (SL) may be established between the two UEs to provide Device-to-Device (D2D) communication without going through a direct link to the BS. The term "SL" may refer to a direct radio link established for communication among devices, such as UEs, rather than communication via the cellular infrastructure (uplink and downlink) as discussed above. In this case, the "SL" is also referred to as a D2D communication link. The D2D communication link may be used in any suitable telecommunications network according to various standards, where the telecommunications network may configure a resource pool for UEs to use during this D2D communication.

[0004] D2D communication may provide various advantages, such as relatively high transmission rates, relatively low latency, etc. In addition, during D2D communication, the traffic concentrated at the base station may be dispersed. In addition, a UE supporting D2D communication, such as a D2D UE, may be used as a relay node to extend the coverage of a base station communicating with a UE.

[0005] D2D communication has evolved into Vehicle-to-Everything (V2X) communication in the Long-Term Evolution (LTE) SL standard. V2X communication technologies cover communications involving vehicles as message sources or destinations. In an NR communication system, both unicast and multicast communications have been introduced as part of the V2X communication standard to further improve the transmission efficiency, for example, on the SL between UEs. During unicast communication, data on the SL is only sent to a specific V2X UE and cannot be decoded by other UEs. In multicast communication, data on the SL is sent to a group of V2X UEs and can be decoded by each receiving UE within the group.

[0006] Currently, NR V2X communication supports two resource allocation modes: 1) Mode 1: A base station (e.g., a gNB) indicates (a number of) SL resources for SL communication to a Transmitting (Tx) UE; 2) Mode 2: The Tx UE selects (a number of) SL resources for SL communication from a resource pool containing SL resources configured by the base station.

[0007] How to allocate resources to a Tx UE is an important topic in NR V2X communication technology, and the NR V2X communication technology should reduce transmission latency and resource waste. Summary of the Invention

[0008] An object of an embodiment of the present disclosure is to provide an improved technical solution for resource allocation in NR V2X communication.

[0009] According to an embodiment of the present disclosure, a method may include: determining resource allocation information indicating at least one set of resources; and transmitting the determined resource allocation information. Each set of resources is associated with a transport block in a set of transport blocks to be transmitted on the SL. Each set of resources may include: a plurality of SL transmission resources, each SL transmission resource configured to carry an SL transmission of the transport block; a plurality of SL feedback resources, each SL feedback resource configured to carry SL feedback information in response to the SL transmission of the transport block; and a plurality of uplink feedback resources, at least one of the plurality of uplink feedback resources configured to carry uplink feedback information in response to the SL transmission of the transport block only if the SL feedback information indicates that the transport block has been successfully decoded.

[0010] According to another embodiment of the present disclosure, a method may include: receiving resource allocation information indicating at least one set of resources; and transmitting the transport block based on the resource allocation information. Each set of resources is associated with a transport block in a set of transport blocks to be transmitted on the SL. Each set of resources may include: a plurality of SL transmission resources, each SL transmission resource configured to carry an SL transmission of the transport block; a plurality of SL feedback resources, each SL feedback resource configured to carry SL feedback information in response to the SL transmission of the transport block; and a plurality of uplink feedback resources, at least one of the plurality of uplink feedback resources configured to carry uplink feedback information in response to the SL transmission of the transport block only if the SL feedback information indicates that the transport block has been successfully decoded.

[0011] According to yet another embodiment of the present disclosure, a device includes: at least one non-transitory computer-readable medium storing computer-executable instructions; at least one receiver; at least one transmitter; and at least one processor coupled to the at least one non-transitory computer-readable medium, the at least one receiver, and the at least one transmitter. The computer-executable instructions are programmed to implement the method according to an embodiment of the present disclosure using the at least one receiver, the at least one transmitter, and the at least one processor.

[0012] Details of one or more examples are set forth in the accompanying drawings and the following description. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] To describe the manner in which the advantages and features of the present disclosure can be obtained, a description of the present disclosure is presented by reference to specific embodiments of the present disclosure illustrated in the accompanying drawings. These drawings only depict exemplary embodiments of the present disclosure and thus are not intended to limit the scope of the present disclosure.

[0014] Figure 1 is a schematic diagram illustrating a dynamic scheduling scheme;

[0015] Figure 2 is a schematic diagram illustrating another resource allocation scheme;

[0016] Figure 3 is a schematic diagram illustrating yet another resource allocation scheme;

[0017] Figure 4 is a flowchart illustrating a method for resource allocation according to an embodiment of the present disclosure;

[0018] Figure 5 is a flowchart illustrating a method for resource allocation according to another embodiment of the present disclosure;

[0019] Figure 6 is a schematic diagram illustrating a resource allocation scheme according to an embodiment of the present disclosure;

[0020] Figure 7 is a schematic diagram illustrating a resource allocation scheme for semi-persistent scheduling (SL) transmission according to an embodiment of the present disclosure;

[0021] Figure 8 is an exemplary block diagram illustrating a device according to an embodiment of the present disclosure; and

[0022] Figure 9 is an exemplary block diagram illustrating a device according to another embodiment of the present disclosure. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The detailed description of the drawings is intended as a description of the currently preferred embodiments of the present disclosure and is not intended to represent the only form in which the present disclosure can be practiced. It should be understood that the same or equivalent functions can be achieved by different embodiments intended to be covered within the spirit and scope of the present disclosure.

[0024] In the NR V2X mode 1 configuration, a base station (BS), such as a gNB, indicates sidelink (SL) and uplink (UL) resources to a transmitting (Tx) UE. The SL and UL resources designated by the base station may mainly include communication resources for supporting the transmission of one or more transport blocks (TBs) on the SL, one or more SL feedback resources for supporting the transmission of feedback information on the SL, and one or more UL feedback resources for supporting the transmission of feedback information on the UL. A TB is a data block or data packet that will be transmitted, for example, by the Tx UE to a receiving (Rx) UE. The transmission of feedback information on the SL or UL is associated with the transmission or retransmission of a TB on the SL and may include feedback information indicating whether the TB has been successfully decoded by the corresponding Rx UE. For example, the feedback information may be an acknowledgement (ACK) feedback indicating that the TB has been successfully decoded, or a negative acknowledgement (NACK) feedback indicating that the TB has not been successfully decoded.

[0025] The base station may transmit resource allocation information to indicate the SL and UL resources to the Tx UE. The specific resource allocation information will vary depending on different resource allocation schemes, which will be described hereinafter in view of different embodiments of the present disclosure.

[0026] For example, in an allocation scheme referred to as "dynamic scheduling", for each SL transmission (initial transmission or retransmission) of a TB, the base station will perform a resource allocation once to schedule or indicate the SL transmission resources, the SL feedback resources in response to the SL transmission, and the UL feedback resources in response to the SL transmission. That is, the indicated SL and UL resources for a TB only include the SL transmission resources, the SL feedback resources, and the UL feedback resources for one complete transmission of the TB (i.e., the SL transmission to the Tx UE and the base station and their associated sidelink and uplink feedback information transmissions).

[0027] Figure 1 is a schematic diagram illustrating the dynamic scheduling scheme.

[0028] As Figure 1 shown in, the base station (e.g., gNB) may transmit a piece of resource allocation information to the Tx UE. In some embodiments of the present disclosure, the resource allocation information may be carried by physical layer downlink control information (DCI). In other embodiments of the present disclosure, the resource allocation information may be carried by higher layer signaling from the base station, such as radio resource control (RRC) signaling. The resource allocation information indicates to the Tx UE a set of resources for a TB. A TB is a data block or data packet that will be transmitted, for example, by the Tx UE. The set of resources may include one SL transmission resource, one SL feedback resource, and one UL feedback resource.

[0029] The SL transmission resources are configured to carry the SL transmission of the TB. The SL feedback resources are configured to carry SL feedback information in response to the SL transmission of the TB. According to an embodiment of the present disclosure, the SL feedback resources can be explicitly indicated in the resource allocation information, for example, by indicating the position of the SL feedback resources in the time domain. According to another embodiment of the present disclosure, the SL feedback resources can be implicitly indicated. For example, although the position of the SL feedback resources in the time domain is not explicitly indicated in the resource allocation information, the association (e.g., relative position) between the SL transmission resources and their associated SL feedback resources in the time domain is predefined by the base station or based on the resource pool configuration.

[0030] The UL feedback resources are configured to carry UL feedback information in response to the SL transmission of the TB. According to an embodiment of the present disclosure, the UL feedback resources can be explicitly indicated in the resource allocation information, for example, by indicating the position of the UL feedback resources in the time domain. According to another embodiment of the present disclosure, the UL feedback resources can be implicitly indicated. For example, although the position of the UL feedback resources in the time domain is not explicitly indicated in the resource allocation information, the association (e.g., relative position) between the SL transmission resources and their associated UL feedback resources in the time domain or the association (e.g., relative position) between the SL feedback resources and their associated UL feedback resources in the time domain is predefined by the base station or based on the resource pool configuration.

[0031] As Figure 1 shown, after receiving the resource allocation information from the base station, the Tx UE can transmit the TB based on the resource allocation information. According to an embodiment of the present disclosure, the Tx UE can transmit the TB to the receiving (Rx) UE on the SL transmission resources indicated by the resource allocation information. Then, the Rx UE can transmit the SL feedback information on the SL feedback resources indicated by the resource allocation information or by the Tx UE (explicitly or implicitly) based on the decoding status of the TB. For example, in the case where the Rx UE has successfully decoded the TB, the Rx UE can transmit an ACK feedback to the Tx UE on the indicated SL feedback resources. In the case where the Rx UE has not successfully decoded the TB, the Rx UE can transmit a NACK feedback to the Tx UE on the indicated SL feedback resources. The ACK feedback and the NACK feedback can be transmitted on the SL feedback channel, such as the Physical Sidelink Feedback Channel (PSFCH). In an embodiment of the present disclosure, the SL feedback information from the Rx UE can use one bit with a value of "1" or "0" to represent whether the TB has been successfully decoded or not, respectively. For example, the value "1" can represent an ACK feedback in response to the SL transmission of the TB, while the value "0" can represent a NACK feedback in response to the SL transmission of the TB. Alternatively, the value "0" can represent an ACK feedback in response to the SL transmission of the TB, while the value "1" can represent a NACK feedback in response to the SL transmission of the TB.

[0032] For a TB transmitted on an SL transmission resource, the Tx UE may monitor the associated SL feedback resource indicated by the resource allocation information (explicit or implicit) to detect the SL feedback information in response to the SL transmission of the TB. The Tx UE may transmit the corresponding UL feedback information to the base station based on the SL feedback information detected on the UL feedback resource indicated by the resource allocation information (explicit or implicit). According to an embodiment, in the case where the Tx UE detects an ACK feedback on the indicated SL feedback resource, the Tx UE may transmit the ACK feedback to the base station on the indicated UL feedback resource. In the case where the Tx UE detects a NACK feedback on the indicated SL feedback resource, the Tx UE may transmit the NACK feedback to the base station on the indicated UL feedback resource. In an embodiment, the UL feedback information may use one bit with values "0" or "1". For example, the value "1" may indicate an ACK feedback in response to the SL transmission of the TB, while the value "0" may indicate a NACK feedback in response to the SL transmission of the TB. Alternatively, the value "0" may indicate an ACK feedback in response to the SL transmission of the TB, while the value "1" may indicate a NACK feedback in response to the SL transmission of the TB.

[0033] According to an embodiment, in response to a NACK feedback for the SL transmission of a TB detected on the indicated UL feedback resource, the base station may indicate another set of resources for the retransmission of the TB and its associated SL and UL feedback information. However, for an ACK feedback for the SL transmission of a TB detected on the indicated UL feedback resource, the base station will determine that the SL transmission of the TB is successful and no retransmission of this TB is required.

[0034] Although Figure 1 only one Rx UE is shown, those of ordinary skill in the art will understand that the solution can be applied to multicast communication where there may be more than one Rx UE. Similarly, the solutions described below can also be applied to multicast communication.

[0035] According to Figure 1 the solution illustrated in, if the SL transmission of a TB fails (i.e., the TB cannot be successfully decoded by the Rx UE), then the Tx UE will detect a NACK feedback on the SL feedback resource. In that case, the Tx UE needs to transmit a NACK feedback on the UL feedback resource. The Tx UE must wait for another resource allocation information indicating a set of resources for the retransmission of the TB. Similarly, the set of resources may include the SL transmission resources for the retransmission, and its associated SL and UL feedback resources. Obviously, Figure 1 the "dynamic scheduling" solution illustrated in may result in a time delay in the case of retransmission, which is an important issue especially for delay-sensitive V2X services.

[0036] Figure 2It is a schematic diagram illustrating another resource allocation scheme. In this scheme, the base station can schedule a set of resources for an initial SL transmission for a TB, one or more SL retransmissions, one or more SL feedback information transmissions associated with the SL transmission and (several) SL retransmissions, and one UL feedback information transmission.

[0037] As Figure 2 shown, the base station (e.g., gNB) can transmit a resource allocation information to the Tx UE. In some embodiments of the present disclosure, the resource allocation information can be carried by physical layer DCI. In other embodiments of the present disclosure, the resource allocation information can be carried by higher layer signaling from the base station, such as RRC signaling. The resource allocation information indicates to the Tx UE a set of resources for the TB. The TB is a data block or data packet that will be transmitted by the Tx UE, for example. The set of resources can include multiple SL transmission resources and corresponding associated SL feedback resources, and one UL feedback resource, where the multiple SL transmission resources can include one SL initial transmission resource and one or more SL retransmission resources.

[0038] Each of the multiple SL transmission resources is configured to carry an SL transmission of the TB, and the SL transmission can be an SL initial transmission or an SL retransmission. The SL initial transmission resource is configured to carry the SL initial transmission, and the SL retransmission resource is configured to carry the SL retransmission.

[0039] Each of the SL feedback resources is associated with a corresponding SL transmission of the TB. The SL feedback resource is configured to carry SL feedback information in response to the corresponding SL transmission of the TB. According to an embodiment of the present disclosure, the SL feedback resource can be explicitly indicated in the resource allocation information, for example, by indicating the position of the SL feedback resource in the time domain. According to another embodiment of the present disclosure, the SL feedback resource can be implicitly indicated. For example, although the position of the SL feedback resource in the time domain is not explicitly indicated in the resource allocation information, the association (e.g., relative position) between the SL transmission resource and its associated SL feedback resource in the time domain is predefined by the base station or based on the resource pool configuration.

[0040] The UL feedback resource is configured to carry UL feedback information in response to the SL transmission of the TB. According to an embodiment of the present disclosure, the UL feedback resource can be explicitly indicated in the resource allocation information, for example, by indicating the position of the UL feedback resource in the time domain. According to another embodiment of the present disclosure, the UL feedback resource can be implicitly indicated. For example, although the position of the UL feedback resource in the time domain is not explicitly indicated in the resource allocation information, the association (e.g., relative position) between the SL initial transmission resource and the UL feedback resource in the time domain is predefined by the base station or based on the resource pool configuration. Those of ordinary skill in the art will understand that the UL feedback resource can be implicitly indicated in other ways.

[0041] According toFigure 2 According to the scheme described in , after receiving resource allocation information from the base station, the Tx UE may transmit the TB based on the resource allocation information. According to an embodiment of the present disclosure, the Tx UE may transmit the TB to the Rx UE on the SL initial transmission resource indicated by the resource allocation information. Then, the Rx UE may transmit the SL feedback information on the associated SL feedback resource indicated by the resource allocation information or by the Tx UE (explicitly or implicitly) based on the decoding status of the TB. For example, in the case where the Rx UE has successfully decoded the TB, the Rx UE may transmit ACK feedback to the Tx UE on the indicated SL feedback resource. In the case where the Rx UE has not successfully decoded the TB, the Rx UE may transmit NACK feedback to the Tx UE on the indicated SL feedback resource. ACK feedback and NACK feedback may be transmitted on a SL feedback channel, such as a PSFCH. In an embodiment of the present disclosure, the SL feedback information from the Rx UE may use a bit with a value of "1" or "0" to indicate that the TB has been or has not been successfully decoded, respectively. For example, a value of "1" may represent ACK feedback in response to SL transmission of a TB, and a value of "0" may represent NACK feedback in response to SL transmission of a TB. Alternatively, a value of "0" may represent ACK feedback in response to SL transmission of a TB, and a value of "1" may represent NACK feedback in response to SL transmission of a TB.

[0042] For a TB transmitted on a SL transmission resource, the Tx UE may monitor the associated SL feedback resources indicated by the resource allocation information (explicitly or implicitly) to detect SL feedback information in response to the SL transmission of the TB. According to an embodiment of the present disclosure, in the case where the Tx UE detects NACK feedback on the associated SL feedback resources, the Tx UE may retransmit the TB on (several) subsequent SL transmission resources indicated by the resource allocation information until the Tx UE detects ACK feedback on the SL feedback resources or all SL transmission resources indicated by the resource allocation information have been used. In the case where the Tx UE detects ACK feedback on the SL feedback resources, the Tx UE will determine that the SL transmission of the TB is successful and retransmission of this TB is not required. That is, the Tx UE will not use the (several) remaining SL transmission resources and (several) associated SL feedback resources indicated for the TB.

[0043] The Tx UE may transmit feedback information, such as ACK or NACK feedback, to the base station on the UL feedback resource indicated by the resource allocation information (explicit or implicit). In the case where the Tx UE detects NACK feedback on all the SL feedback resources indicated by the resource allocation information, the Tx UE may transmit the NACK feedback to the base station on the indicated UL feedback resource. In an embodiment, the UL feedback information may use one bit with values "0" or "1". For example, the value "1" may indicate ACK feedback in response to the SL transmission of the TB, while the value "0" may indicate NACK feedback in response to the SL transmission of the TB. Alternatively, the value "0" may indicate ACK feedback in response to the SL transmission of the TB, while the value "1" may indicate NACK feedback in response to the SL transmission of the TB.

[0044] According to an embodiment, in response to detecting NACK feedback for the SL transmission of the TB on the indicated UL feedback resource, the base station may indicate another set of resources for the retransmission of the TB and its associated SL and UL feedback information. In response to detecting ACK feedback for the SL transmission of the TB on the indicated UL feedback resource, the base station will determine that the SL transmission of the TB is successful and no retransmission of this TB is required.

[0045] However, since only one UL feedback resource is configured for all SL transmissions, in the time domain, the UL feedback resource must be after all the indicated SL transmission resources and SL feedback resources. The Tx UE can only transmit feedback information, such as ACK or NACK feedback, to the base station on a single UL feedback resource. Therefore, if the TB has been successfully decoded by the Rx UE before the last SL transmission resource indicated by the resource allocation information, the base station cannot reallocate these resources for the transmission of another TB due to not receiving the ACK feedback in time. Thus, the (several) remaining SL transmission resources and (several) associated SL feedback resources indicated for the TB will be wasted.

[0046] Figure 3 is a schematic diagram illustrating another resource allocation scheme. In this scheme, the base station may schedule a set of resources for an initial SL transmission of a TB, one or more SL retransmissions, one or more SL feedback information transmissions associated with the SL transmission and (several) SL retransmissions, and more than one UL feedback information transmission.

[0047] As Figure 3As shown, a base station (e.g., gNB) may transmit a resource allocation information to a Tx UE. In some embodiments of the present disclosure, the resource allocation information may be carried by physical layer DCI. In other embodiments of the present disclosure, the resource allocation information may be carried by higher layer signaling from the base station, such as RRC signaling. The resource allocation information indicates to the Tx UE a set of resources for a TB. The set of resources may include multiple resource subsets (each subset is Figure 3 surrounded by a dashed box in). Each resource subset may include an SL transmission resource, an associated SL feedback resource, and an associated UL feedback resource. The first resource subset among the multiple resource subsets may be configured for the SL initial transmission of the TB, and the (some) other resource subsets may be configured for the SL retransmission of the TB.

[0048] The SL transmission resource in each resource subset indicated by the resource allocation information is configured to carry the SL transmission (SL initial transmission or SL retransmission) of the TB.

[0049] The SL feedback resource in each resource subset is configured to carry SL feedback information in response to the associated SL transmission of the TB. According to an embodiment of the present disclosure, the SL feedback resource may be explicitly indicated in the resource allocation information, for example, by indicating the position of the SL feedback resource in the time domain. According to another embodiment of the present disclosure, the SL feedback resource may be implicitly indicated. For example, although the position of the SL feedback resource in the time domain is not explicitly indicated in the resource allocation information, the association (e.g., relative position) between the SL transmission resource and its associated SL feedback resource in the time domain is predefined by the base station or based on the resource pool configuration.

[0050] The UL feedback resource in each resource subset is configured to carry UL feedback information in response to the associated SL transmission of the TB. According to an embodiment of the present disclosure, the UL feedback resource may be explicitly indicated in the resource allocation information, for example, by indicating the position of the UL feedback resource in the time domain. According to another embodiment of the present disclosure, the UL feedback resource may be implicitly indicated. For example, although the position of the UL feedback resource in the time domain is not explicitly indicated in the resource allocation information, the association (e.g., relative position) between the SL transmission resource and its associated UL feedback resource in the time domain or the association (e.g., relative position) between the SL feedback resource and its associated UL feedback resource in the time domain is predefined by the base station or based on the resource pool configuration. Those of ordinary skill in the art will understand that the UL feedback resource may be implicitly indicated in other ways.

[0051] According to Figure 3In the solution described in [reference], after receiving resource allocation information from the base station, the Tx UE may transmit the TB based on the resource allocation information. According to an embodiment of the present disclosure, the Tx UE may transmit the TB to the Rx UE on the SL transmission resources in the first resource subset indicated by the resource allocation information. Subsequently, the Rx UE may transmit SL feedback information on the associated SL feedback resources indicated by the resource allocation information or by the Tx UE (explicitly or implicitly) based on the decoding status of the TB. For example, in the case where the Rx UE has successfully decoded the TB, the Rx UE may transmit an ACK feedback to the Tx UE on the associated SL feedback resources. In the case where the Rx UE has not successfully decoded the TB, the Rx UE may transmit a NACK feedback to the Tx UE on the associated SL feedback resources. The ACK feedback and the NACK feedback may be transmitted on an SL feedback channel, such as the PSFCH. In an embodiment of the present disclosure, the SL feedback information from the Rx UE may use one bit with a value of "1" or "0" respectively to indicate whether the TB has been successfully decoded or not. For example, the value "1" may indicate an ACK feedback in response to the SL transmission of the TB, while the value "0" may indicate a NACK feedback in response to the SL transmission of the TB. Alternatively, the value "0" may indicate an ACK feedback in response to the SL transmission of the TB, while the value "1" may indicate a NACK feedback in response to the SL transmission of the TB.

[0052] For the TB transmitted on the SL transmission resources, the Tx UE may monitor the associated SL feedback resources indicated by the resource allocation information (explicitly or implicitly) to detect the SL feedback information in response to the SL transmission of the TB. The Tx UE may transmit the corresponding UL feedback information to the base station based on the SL feedback information detected on the associated UL feedback resources indicated by the resource allocation information (explicitly or implicitly).

[0053] According to an embodiment, in the case where the Tx UE detects a NACK feedback on the associated SL feedback resources, the Tx UE may transmit a NACK feedback to the base station on the associated UL feedback resources, and then retransmit the TB on the SL transmission resources in the subsequent resource subset(s) indicated by the resource allocation information until the Tx UE detects an ACK feedback on the SL feedback resources or all the SL transmission resources indicated by the resource allocation information have been used.

[0054] In the case where the Tx UE detects an ACK feedback on the associated SL feedback resources, the Tx UE may transmit an ACK feedback to the base station on the associated UL feedback resources indicated by the resource allocation information (explicitly or implicitly). The Tx UE will determine that the SL transmission of the TB is successful and no retransmission of this TB is required. Therefore, the Tx UE will not use the remaining SL transmission resource(s) and the associated SL and UL feedback resource(s) indicated for the TB.

[0055] In an embodiment, the UL feedback information may use one bit with values "1" or "0". For example, the value "1" may indicate an ACK feedback in response to the SL transmission of a TB, while the value "0" may indicate a NACK feedback in response to the SL transmission of a TB. Alternatively, the value "0" may indicate an ACK feedback in response to the SL transmission of a TB, while the value "1" may indicate a NACK feedback in response to the SL transmission of a TB.

[0056] According to an embodiment, in response to an ACK feedback in response to the SL transmission of a TB detected on a UL feedback resource, the base station may determine that the SL transmission of the TB is successful and that a retransmission of this TB is not required. Accordingly, the base station may release the (unused) SL transmission resources and the (SL and UL) feedback resources in the indicated set of resources such that they can be allocated to another TB. In response to a NACK feedback in response to the SL transmission of a TB detected on a UL feedback resource, the base station does not need to perform resource allocation for the TB, unless the UL feedback resource is the last UL feedback resource in the indicated set of resources, i.e., all SL transmission resources indicated by the resource allocation information have been used. In response to a NACK feedback in response to the SL transmission of a TB detected on the last UL feedback resource in the indicated set of resources, the base station may indicate another set of resources for the retransmission of the TB and its associated SL and UL feedback information.

[0057] In Figure 3 the number of SL transmission resources, the number of SL feedback resources, and the number of UL feedback resources indicated in the resource allocation information are the same. According to an alternative embodiment of the present disclosure, the number of SL transmission resources, the number of SL feedback resources, and the number of UL feedback resources indicated in the resource allocation information may be different from each other. For example, the resource allocation information may indicate M SL transmission resources, N SL feedback resources, and Q UL feedback resources for a TB, where M, N, and Q are integers and M≥N≥Q≥1. That is, the resource allocation information may schedule M SL transmissions for a TB, schedule N SL feedback transmissions for the M SL transmissions, and schedule Q UL feedback transmissions for the N SL feedback transmissions (i.e., each i-th SL transmission may have one SL feedback, each j-th SL transmission may have one UL feedback, and each k-th SL feedback may have one UL feedback, where i = roundup(M / N), j = roundup(M / Q), k = roundup(N / Q), and the function "roundup(x)" means rounding x up to the nearest integer). The values of i, j, k, M, N, and Q may be determined based on traffic reliability or latency requirements.

[0058] According to Figure 3In the solution described in , if the Tx UE detects a NACK feedback for a TB on the SL feedback resource, but there is still one or more unused SL transmission resources available for the retransmission of the TB in the indicated set of resources, then the Tx UE does not need the base station to indicate another set of resources for the retransmission of the TB. In this case, from the perspective of the system, the NACK feedback on the UL feedback resource is useless feedback.

[0059] Figure 4 FIG. 400 is a flowchart illustrating a method 400 for resource allocation according to an embodiment of the present disclosure. Although described with respect to a base station, it should be understood that other devices may be configured to perform methods similar to Figure 4 the method of

[0060] As Figure 4 shown in FIG. 400, in step 402, the base station may determine resource allocation information indicating at least one set of resources. Each set of resources is associated with a TB in a set of TBs to be transmitted on the SL. Each set of resources may include: a plurality of SL transmission resources, each SL transmission resource being configured to carry an SL transmission of a TB; a plurality of SL feedback resources, each SL feedback resource being configured to carry SL feedback information in response to an SL transmission of a TB; and a plurality of UL feedback resources, at least one of the plurality of UL feedback resources being configured to carry UL feedback information in response to an SL transmission of a TB only if the SL feedback information indicates that the TB has been successfully decoded. The resource allocation information may indicate a set of resources for one TB to be transmitted on the SL. Alternatively, in some other embodiments of the present disclosure, the resource allocation information may indicate multiple sets of resources for the set of TBs to be transmitted on the SL.

[0061] In step 404, the base station will cause the determined resource allocation information to be transmitted, for example, to the Tx UE so that the Tx UE can transmit the set of TBs.

[0062] In some embodiments of the present disclosure, the base station may receive ACK information indicating receipt of the resource allocation information from the Tx UE. Accordingly, the base station may determine that the resource allocation information has been successfully received by the Tx UE and does not require retransmission of the resource allocation information.

[0063] Figure 5 FIG. 500 is a flowchart illustrating a method 500 for resource allocation according to another embodiment of the present disclosure. Although described with respect to a Tx UE, it should be understood that other devices may be configured to perform methods similar to Figure 5 the method of

[0064] As Figure 5As shown, in step 502, the Tx UE may receive resource allocation information indicating at least one set of resources. Each set of resources is associated with a TB in a set of TBs to be transmitted on the SL. Each set of resources may include: multiple SL transmission resources, each SL transmission resource being configured to carry the SL transmission of the TB; multiple SL feedback resources, each SL feedback resource being configured to carry SL feedback information in response to the SL transmission of the TB; and multiple UL feedback resources, at least one of the multiple UL feedback resources being configured to carry UL feedback information in response to the SL transmission of the TB only if the SL feedback information indicates that the TB has been successfully decoded. The resource allocation information may indicate a set of resources for one TB to be transmitted on the SL. Alternatively, in some other embodiments of the present disclosure, the resource allocation information may indicate multiple sets of resources for the set of TBs to be transmitted on the SL.

[0065] After successfully decoding the resource allocation information, in step 504, the Tx UE may transmit the (s)TB based on the resource allocation information.

[0066] In some embodiments of the present disclosure, the Tx UE may transmit ACK information verifying the reception of the resource allocation information to the base station, which will help the base station determine whether retransmission of the resource allocation information is needed.

[0067] Figure 6 is a schematic diagram illustrating a resource allocation scheme according to an embodiment of the present disclosure. Similar to Figure 3 the scheme illustrated in, in this scheme, the base station may schedule a set of resources for an initial SL transmission of a TB, one or more SL retransmissions, one or more SL feedback information transmissions associated with the SL transmission and the (s)SL retransmissions, and more than one UL feedback information transmission.

[0068] As Figure 6 shown, the base station (e.g., gNB) may transmit a piece of resource allocation information to the Tx UE. In some embodiments of the present disclosure, the resource allocation information may be carried by physical layer DCI. In other embodiments, the resource allocation information may be carried by higher layer signaling of the base station, such as RRC signaling. The resource allocation information indicates to the Tx UE a set of resources for the TB. The TB is a data block or data packet to be transmitted by the Tx UE, for example. The set of resources may include multiple resource subsets (each subset being Figure 6 surrounded by a dashed box in). Each resource subset may include one SL transmission resource, one associated SL feedback resource, and one associated UL feedback resource. The first resource subset among the multiple resource subsets may be configured for the SL initial transmission of the TB, and the (s)other resource subsets may be configured for the SL retransmission of the same TB.

[0069] The SL transmission resources in each resource subset indicated by the resource allocation information are configured to carry the SL transmission (SL initial transmission or SL retransmission) of the TB.

[0070] The SL feedback resources in each resource subset are configured to carry SL feedback information in response to the associated SL transmission of the TB. According to an embodiment of the present disclosure, the SL feedback resources can be explicitly indicated in the resource allocation information, for example, by indicating the position of the SL feedback resources in the time domain. According to another embodiment of the present disclosure, the SL feedback resources can be implicitly indicated. For example, although the position of the SL feedback resources in the time domain is not explicitly indicated in the resource allocation information, the association (e.g., relative position) between the SL transmission resources and their associated SL feedback resources in the time domain is predefined by the base station or based on the resource pool configuration

[0071] The UL feedback resources in each resource subset are configured to carry UL feedback information in response to the SL transmission of the TB. Different from the UL feedback resources in the scheme described in Figure 3 - 5 , the UL feedback resources in this scheme can be configured to carry UL feedback information only when the associated SL feedback information indicates that the TB has been successfully decoded. In other words, the UL feedback resources are configured to carry only ACK feedback (i.e., the UL feedback information is only ACK feedback). In an alternative embodiment of the present disclosure, the UL feedback resources in only the last resource subset indicated by the resource allocation information are configured to carry ACK or NACK feedback (ACK / NACK feedback) in response to the last SL transmission of the TB, and all other UL feedback resources are configured to carry only ACK feedback.

[0072] According to an embodiment of the present disclosure, the UL feedback resources can be explicitly indicated in the resource allocation information, for example, by indicating the position of the UL feedback resources in the time domain. According to another embodiment of the present disclosure, the UL feedback resources can be implicitly indicated. For example, although the position of the UL feedback resources in the time domain is not explicitly indicated in the resource allocation information, the association (e.g., relative position) between the SL transmission resources and their associated UL feedback resources in the time domain or the association (e.g., relative position) between the SL feedback resources and their associated UL feedback resources in the time domain is predefined by the base station or based on the resource pool configuration.

[0073] According to Figure 6In the solution described in [reference], after receiving resource allocation information from the base station, the Tx UE can transmit the TB based on the resource allocation information. According to an embodiment of the present disclosure, the Tx UE can transmit the TB to the Rx UE on the SL transmission resources in the first resource subset indicated by the resource allocation information. Then, the Rx UE can transmit SL feedback information on the associated SL feedback resources indicated by the resource allocation information or by the Tx UE (explicitly or implicitly) based on the decoding status of the TB. For example, in the case where the Rx UE has successfully decoded the TB, the Rx UE can transmit an ACK feedback to the Tx UE on the associated SL feedback resources. In the case where the Rx UE has not successfully decoded the TB, the Rx UE can transmit a NACK feedback to the Tx UE on the associated SL feedback resources. The ACK feedback and the NACK feedback can be transmitted on the SL feedback channel, such as the PSFCH. In an embodiment of the present disclosure, the SL feedback information from the Rx UE can use one bit with a value of "1" or "0" respectively to indicate whether the TB has been successfully decoded or not. For example, the value "1" can indicate an ACK feedback in response to the SL transmission of the TB, while the value "0" can indicate a NACK feedback in response to the SL transmission of the TB. Alternatively, the value "0" can indicate an ACK feedback in response to the SL transmission of the TB, while the value "1" can indicate a NACK feedback in response to the SL transmission of the TB.

[0074] For the TB transmitted on the SL transmission resources, the Tx UE can monitor the associated SL feedback resources indicated by the resource allocation information (explicitly or implicitly) to detect the SL feedback information in response to the SL transmission of the TB. According to an embodiment of the present disclosure, in the case where the Tx UE detects an ACK feedback on the associated SL feedback resources, the Tx UE can transmit an ACK feedback to the base station on the associated UL feedback resources. The Tx UE will determine that the SL transmission of the TB is successful and no retransmission of this TB is required. Therefore, the Tx UE will not use the (remaining) SL transmission resources and the (associated) SL and UL feedback resources indicated for the TB. In the case where the Tx UE detects a NACK feedback on the associated SL feedback resources, the Tx UE does not transmit any feedback to the base station, but retransmits the TB on the (SL) transmission resources in the (subsequent) resource subsets indicated by the resource allocation information until the Tx UE detects an ACK feedback on the SL feedback resources or all the SL transmission resources indicated by the resource allocation information have been used. In an alternative embodiment of the present disclosure, the Tx UE can transmit a NACK feedback on the UL feedback resources in the last resource subset in response to detecting a NACK feedback on the SL feedback resources in the last resource subset indicated by the resource allocation information.

[0075] In some embodiments of the present disclosure, the SL feedback information may be only ACK feedback. That is, the Rx UE may transmit only ACK feedback on the SL feedback resource in response to the transmission of the TB. In this case, the Tx UE may retransmit the TB on the SL transmission resource in the next resource subset indicated by the resource allocation information in response to not detecting ACK feedback on the SL feedback resource. Not detecting ACK feedback on the SL feedback resource may indicate that the TB has not been successfully decoded or discontinuous transmission (DTX) of the Rx UE. DTX of the Rx UE means that the Rx UE fails to decode the sidelink control information indicating the TB on the sidelink control channel (e.g., the Physical Sidelink Control Channel (PSCCH)), such that the Rx UE does not transmit feedback information on the feedback channel (e.g., the PSFCH).

[0076] In Figure 6 the scheme illustrated in, according to an embodiment of the present disclosure, in response to detecting ACK feedback for the SL transmission of the TB on the UL feedback resource, the base station may determine that the SL transmission of the TB is successful and no retransmission of this TB is required. Accordingly, the base station may release the unused SL transmission resources and the SL and UL feedback resources in the indicated set of resources such that they can be allocated to another TB. In the case where all UL feedback resources are configured to carry only ACK feedback, the base station may indicate another set of resources for the SL transmission of the TB in response to not detecting ACK feedback on all UL feedback resources. In the case where the UL feedback resource in the last resource subset indicated by the resource allocation information is configured to carry ACK or NACK feedback, the base station may indicate another set of resources for the SL transmission of the TB in response to detecting NACK feedback on the last UL feedback resource in the indicated set of resources.

[0077] In Figure 6Among them, the number of SL transmission resources, the number of SL feedback resources, and the number of UL feedback resources indicated in the resource allocation information are the same. According to an alternative embodiment of the present disclosure, the number of SL transmission resources, the number of SL feedback resources, and the number of UL feedback resources indicated in the resource allocation information may be different from each other. For example, the resource allocation information may indicate M SL transmission resources, N SL feedback resources, and Q UL feedback resources for a TB, where M, N, and Q are integers, and M≥N≥Q≥1. That is, the resource allocation information may schedule M SL transmissions for a TB, schedule N SL feedback transmissions for M SL transmissions, and schedule Q UL feedback transmissions for N SL feedback transmissions (i.e., each i-th SL transmission may have one SL feedback, each j-th SL transmission may have one UL feedback, and each k-th SL feedback may have one UL feedback, where i = roundup(M / N), j = roundup(M / Q), k = roundup(N / Q), and the function "roundup(x)" means rounding x up to the nearest integer). The values of i, j, k, M, N, and Q may be determined based on the reliability or latency requirements of the traffic.

[0078] According to Figure 6 the scheme described in, since NACK feedback is not used on the UL feedback resources (except for the last UL feedback resource in some cases), the code domain feedback indicator corresponding to the NACK feedback can be used for other UEs whose feedback is indicated on the same UL feedback resource, and thus the base station can support UL feedback from more UEs on the same UL feedback resource.

[0079] Figure 7 is a schematic diagram illustrating a resource allocation scheme for semi-persistent scheduling of SL transmissions according to an embodiment of the present disclosure.

[0080] As Figure 7 shown in, the base station (e.g., gNB) may transmit a piece of resource allocation information to the Tx UE to indicate multiple sets of resources for a group of TBs to be transmitted on the SL (each set is represented by Figure 7 the dashed box in). In some embodiments, the resource allocation information may be carried by higher layer signaling, such as RRC signaling, and the semi-persistent scheduling of SL transmissions may be activated or deactivated by physical layer DCI.

[0081] Each set of resources indicated by the resource allocation information is associated with one TB in the group of TBs, and may be associated with Figure 6The set of resources described therein is similar. That is, each set of resources may include multiple SL transmission resources, multiple SL feedback resources, and multiple UL feedback resources, where each SL transmission resource is configured to carry the SL transmission of a TB, each SL feedback resource is configured to carry SL feedback information in response to the SL transmission of a TB, and at least one of the multiple UL feedback resources is configured to carry a UL feedback transmission in response to the SL transmission of a TB only if the SL feedback information indicates that the TB has been successfully decoded. Similar to Figure 6 the scheme described therein, the number of SL transmission resources, the number of SL feedback resources, and the number of UL feedback resources in a set of resources indicated by resource allocation information may be the same or different in Figure 7 the scheme described therein.

[0082] In an embodiment of the present disclosure, the UL feedback information carried by at least one of the multiple UL feedback resources may be an ACK or a release feedback, which may be a one-bit indicator with a value of "1" or "0". For example, the value "1" may represent an ACK feedback in response to the SL transmission of a TB, and the value "0" may represent a release indicator. Alternatively, the value "0" may represent an ACK feedback in response to the SL transmission of a TB, and the value "1" may represent a release indicator. In another embodiment of the present disclosure, the multiple UL feedback resources in a set of resources indicated by resource allocation information may further include a last UL feedback resource, and the last UL feedback resource is configured to carry only a release feedback in response to the last SL transmission of a TB associated with the set of resources, where the release feedback may be a release indicator.

[0083] According to Figure 7In the solution described, after receiving resource allocation information from the base station, the Tx UE can transmit the TB based on the resource allocation information. Subsequently, the Rx UE can transmit SL feedback information on the associated SL feedback resource indicated by the resource allocation information or by the Tx UE (explicitly or implicitly), based on the decoding status of the TB. For example, in the case where the Rx UE has successfully decoded the TB, the Rx UE can transmit an ACK feedback to the Tx UE on the associated SL feedback resource. In the case where the Rx UE has not successfully decoded the TB, the Rx UE can transmit a NACK feedback to the Tx UE on the associated SL feedback resource. The ACK feedback and the NACK feedback can be transmitted on an SL feedback channel, such as the PSFCH. In an embodiment of the present disclosure, the SL feedback information from the Rx UE can use one bit with a value of "1" or "0" respectively to indicate whether the TB has been successfully decoded or not. For example, the value "1" can represent an ACK feedback in response to the SL transmission of the TB, while the value "0" can represent a NACK feedback in response to the SL transmission of the TB. Alternatively, the value "0" can represent an ACK feedback in response to the SL transmission of the TB, while the value "1" can represent a NACK feedback in response to the SL transmission of the TB.

[0084] For a TB transmitted on an SL transmission resource, the Tx UE may monitor the associated SL feedback resource indicated by the resource allocation information (explicit or implicit) to detect the SL feedback information in response to the SL transmission of the TB. According to an embodiment of the present disclosure, in the case where the Tx UE detects a NACK feedback on the associated SL feedback resource, the Tx UE does not transmit any feedback to the base station, but retransmits the TB on the subsequent SL transmission resource(s) indicated by the resource allocation information until the Tx UE detects an ACK feedback on the SL feedback resource or all the SL transmission resources indicated by the resource allocation information have been used. In the case where the Tx UE detects an ACK feedback on the SL feedback resource associated with the current transmission of the TB, the Tx UE may determine that the SL transmission of the TB is successful and no retransmission of this TB is required. Therefore, the Tx UE will not use the remaining SL transmission resource(s) in the current set of resources and the associated SL and UL feedback resource(s). The Tx UE may further determine whether there is another TB to be transmitted on the SL. If there is another TB to be transmitted on the SL, then the Tx UE may transmit an ACK feedback on the UL feedback resource associated with the current transmission of the TB. The Tx UE may further transmit the next TB in the set of TBs on the SL transmission resource in the next set of resources. If there is no TB to be transmitted on the SL, then the Tx UE may transmit a release feedback on the associated UL feedback resource. The Tx UE may determine that all the TBs in the set of TBs have been successfully transmitted and these TBs do not require transmission / feedback resources. Therefore, the Tx UE will not use the remaining resources indicated by the resource allocation information indicated for the set of TBs.

[0085] In some embodiments of the present disclosure, the SL feedback information may be only ACK feedback. That is, the Rx UE may transmit only an ACK feedback on the SL feedback resource in response to the transmission of the TB. In this case, the Tx UE may retransmit the TB on the SL transmission resource in the next resource subset indicated by the resource allocation information in response to not detecting an ACK feedback on the SL feedback resource. Not detecting an ACK feedback on the SL feedback resource may indicate that the TB has not been successfully decoded or DTX of the Rx UE. DTX of the Rx UE means that the Rx UE fails to decode the sidelink control information indicating the TB on the sidelink control channel (e.g., PSCCH), such that the Rx UE does not transmit feedback information on the feedback channel (e.g., PSFCH).

[0086] In Figure 7In the solution described in, according to an embodiment of the present disclosure, in response to detecting an ACK feedback of the SL transmission of a TB on the UL feedback resource in the current set of resources among multiple sets of resources indicated by the resource allocation information, the base station may determine that the SL transmission of the TB is successful and no retransmission of this TB is required. Therefore, the base station may release (some of) the unused SL transmission resources and (some of) the SL and UL feedback resources in the current set of resources so that they can be allocated to another TB. The base station may stop monitoring (some of) the unused UL feedback resources in the current set of resources. In response to a release feedback on the UL feedback resource in the current set of resources among multiple sets of resources indicated by the resource allocation information, the base station may determine that all the TBs in the set of TBs have been successfully transmitted and these TBs do not require transmission / feedback resources. Therefore, the base station may release (some of) all the unused SL transmission resources and (some of) the SL and UL feedback resources in the multiple sets of resources so that they are allocated to another TB. The base station may stop monitoring (some of) all the unused UL feedback resources in the multiple sets of resources.

[0087] In Figure 6 and 7 in the solution described in, after receiving the resource allocation information, the Tx UE may transmit ACK information confirming the reception of the resource allocation information to the base station, which will help the base station determine whether retransmission of the resource allocation information is required.

[0088] In an embodiment of the present disclosure, the ACK information confirming the reception of the resource allocation information may be an independent UL ACK transmission from the Tx UE on the physical UL control channel (PUCCH). The PUCCH resource carrying the ACK information may have a fixed (e.g., predefined) offset in the time domain relative to the resource carrying the resource allocation information. In the case where the base station receives ACK information from the Tx UE on the expected resource, the base station does not reallocate the set of resources indicated by the resource allocation information to other UEs. In the case where the base station does not receive ACK information from the Tx UE on the expected resource, the base station will transmit another resource allocation information to the Tx UE.

[0089] In another embodiment of the present disclosure, the first UL ACK feedback on the UL feedback resource in a (some of) set of resources indicated by the resource allocation information may serve as the ACK information confirming the reception of the resource allocation information.

[0090] Figure 8 An exemplary block diagram of a device 800 according to an embodiment of the present disclosure is illustrated. In some embodiments of the present disclosure, the device 800 may be a base station (e.g., gNB), which may at least execute Figure 4 the method described in.

[0091] As Figure 8As shown, device 800 may include a receiver 802, a transmitter 804, a non-transitory computer-readable medium 806, and a processor 808 coupled to the receiver 802, the transmitter 804, and the non-transitory computer-readable medium 806.

[0092] Although in Figure 8 , elements such as the receiver 802, the transmitter 804, the non-transitory computer-readable medium 806, and the processor 808 are described in the singular, the plural form is contemplated unless explicitly stated to be limited to the singular form. In some embodiments of the present disclosure, the receiver 802 and the transmitter 804 are combined into a single device, such as a transceiver. In certain embodiments of the present disclosure, device 800 may further include an input device, a memory, and / or other components.

[0093] In some embodiments of the present disclosure, the non-transitory computer-readable medium 806 may store computer-executable instructions thereon, the computer-executable instructions being programmed to implement steps of a method such as, for example, as described in view of Figure 4 .

[0094] Figure 9 An exemplary block diagram of a device 900 in accordance with another embodiment of the present disclosure is illustrated. In some embodiments of the present disclosure, device 900 may be a UE (e.g., a Tx UE) that can at least perform Figure 5 the method illustrated therein.

[0095] As Figure 9 shown, device 900 may include a receiver 902, a transmitter 904, a non-transitory computer-readable medium 906, and a processor 908 coupled to the receiver 902, the transmitter 904, and the non-transitory computer-readable medium 906.

[0096] Although in Figure 9 , elements such as the receiver 902, the transmitter 904, the non-transitory computer-readable medium 906, and the processor 908 are described in the singular, the plural form is contemplated unless explicitly stated to be limited to the singular form. In some embodiments of the present disclosure, the receiver 902 and the transmitter 904 are combined into a single device, such as a transceiver. In certain embodiments of the present disclosure, device 900 may further include an input device, a memory, and / or other components.

[0097] In some embodiments of the present disclosure, the non-transitory computer-readable medium 906 may store computer-executable instructions thereon, the computer-executable instructions being programmed to implement steps of a method such as, for example, as described in view of Figure 5 .

[0098] Those of ordinary skill in the art will understand that the steps of the methods described in connection with the aspects disclosed herein can be embodied directly in hardware, in software modules executed by a processor, or in a combination of both. The software modules can reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. Additionally, in some aspects, the steps of the methods can reside on a non-transitory computer-readable medium as code and / or instructions in one or any combination or set, which can be incorporated into a computer program product.

[0099] Although the present disclosure has been described in connection with its specific embodiments, it is apparent that many alternatives, modifications, and variations will be obvious to those skilled in the art. For example, the various components of the embodiments can be interchanged, added, or replaced in other embodiments. Also, all elements of each figure are not necessary for the operation of the disclosed embodiments. For example, by simply employing the elements of the independent claims, those of ordinary skill in the art will be able to make and use the teachings of the present disclosure. Accordingly, the embodiments of the present disclosure as set forth herein are intended to be illustrative and not restrictive. Various changes can be made without departing from the spirit and scope of the present disclosure.

[0100] In this document, the terms "includes", "including", or any other variant thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element preceded by "a", "an", etc. does not, without further constraints, preclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element. Also, the term "another" is defined as at least second or more. As used herein, the term "has", etc. is defined as "includes".

Claims

1. A method for resource allocation performed by a base station, the method comprises: determining resource allocation information indicating at least one set of resources, wherein each set of resources is associated with a transport block in a set of transport blocks to be transmitted on a sidelink, and wherein each set of resources comprises: a plurality of sidelink transmission resources, each sidelink transmission resource being configured to carry a sidelink transmission of the transport block; a plurality of sidelink feedback resources, each sidelink feedback resource being configured to carry sidelink feedback information in response to the sidelink transmission of the transport block; and a plurality of uplink feedback resources, at least one of the plurality of uplink feedback resources being configured to carry uplink feedback information in response to the sidelink transmission of the transport block only when the sidelink feedback information indicates that the transport block has been successfully decoded; and transmitting the determined resource allocation information, wherein transmitting the determined resource allocation information comprises indicating each resource in the at least one set of resources before the sidelink transmission of the transport block.

2. The method according to claim 1, wherein the resource allocation information indicates a set of resources for one transport block to be transmitted on a sidelink.

3. The method according to claim 2, wherein the resource allocation information is carried by physical layer downlink control information or radio resource control signaling.

4. The method according to claim 2, wherein the at least one of the plurality of uplink feedback resources is configured to carry only an acknowledgement feedback.

5. The method according to claim 4, further comprising determining and transmitting another resource allocation information for the sidelink transmission of the transport block in response to not detecting an acknowledgement feedback on all of the plurality of uplink feedback resources.

6. The method according to claim 2, wherein the plurality of uplink feedback resources further comprises a last uplink feedback resource, the last uplink feedback resource being configured to carry an acknowledgement or a negative acknowledgement feedback in response to a last sidelink transmission of the transport block.

7. The method according to claim 6, further comprising determining and transmitting another resource allocation information for the sidelink transmission of the transport block in response to detecting a negative acknowledgement feedback on the last uplink feedback resource.

8. The method according to claim 1, wherein the resource allocation information indicates M sidelink transmission resources, N sidelink feedback resources, and Q uplink feedback resources for the transport block, wherein M, N, Q are integers, and M≥N≥Q≥1.

9. The method according to claim 1, wherein the transmission on the sidelink is semi-persistent scheduled, and the resource allocation information indicates multiple sets of resources for the set of transport blocks to be transmitted on the sidelink.

10. The method according to claim 9, wherein the resource allocation information is carried by radio resource control signaling.

11. The method according to claim 9, wherein at least one of the plurality of uplink feedback resources is configured to carry an acknowledgement or release feedback.

12. The method according to claim 11, comprising releasing unused resources in a current set of resources associated with one transport block in the set of transport blocks upon detecting the acknowledgement feedback on an uplink feedback resource.

13. The method according to claim 12, comprising ceasing to monitor unused uplink feedback resources in the current set of resources.

14. The method according to claim 11, comprising releasing unused resources in the plurality of sets of resources upon detecting the release feedback on an uplink feedback resource.

15. The method according to claim 14, comprising ceasing to monitor unused uplink feedback resources in the plurality of sets of resources.

16. The method according to claim 9, wherein the plurality of uplink feedback resources in each set of resources further comprises a last uplink feedback resource configured to carry only a release feedback in response to a last sidelink transmission of a corresponding transport block associated with the set of resources indicated by the resource allocation information.

17. The method according to claim 1, further comprising receiving received acknowledgement information confirming the resource allocation information.

18. A user equipment (UE), which comprises: at least one memory; and at least one processor coupled to the at least one memory and configured to cause the UE to: receive resource allocation information indicating at least one set of resources, wherein receiving the resource allocation information comprises receiving an indication of each resource in the at least one set of resources prior to a sidelink transmission of a transport block, each set of resources being associated with a transport block in a set of transport blocks to be transmitted on the sidelink, and each set of resources comprising: a plurality of sidelink transmission resources, each sidelink transmission resource being configured to carry the sidelink transmission of the transport block; a plurality of sidelink feedback resources, each sidelink feedback resource being configured to carry sidelink feedback information in response to the sidelink transmission of the transport block; and a plurality of uplink feedback resources, at least one of the plurality of uplink feedback resources being configured to carry uplink feedback information in response to the sidelink transmission of the transport block only when the sidelink feedback information indicates that the transport block has been successfully decoded; and transmit the transport block based on the resource allocation information.

19. The UE according to claim 18, wherein the resource allocation information indicates a set of resources for one transport block to be transmitted on the sidelink.

20. The UE according to claim 19, wherein at least one of the plurality of uplink feedback resources is configured to carry only an acknowledgement feedback.

21. The UE according to claim 20, wherein the at least one processor is further configured to cause the UE to transmit the acknowledgement feedback in response to detecting an acknowledgement sidelink feedback.

22. The UE according to claim 20, wherein the at least one processor is further configured to cause the UE to retransmit the transport block on a sidelink transmission resource immediately adjacent to the previous sidelink transmission resource in response to not detecting an acknowledgement sidelink feedback on a sidelink feedback resource associated with the previous sidelink transmission resource.

23. The UE according to claim 18, wherein the at least one processor is further configured to cause the UE to receive another resource allocation information for the sidelink transmission of the transport block.

24. The UE according to claim 19, wherein the plurality of uplink feedback resources further includes a last uplink feedback resource configured to carry an acknowledgement or negative acknowledgement feedback in response to a last sidelink transmission of the transport block.

25. The UE according to claim 18, wherein the resource allocation information indicates M sidelink transmission resources, N sidelink feedback resources, and Q uplink feedback resources for the transport block, where M, N, and Q are integers and M≥N≥Q≥1.

26. The UE according to claim 18, wherein the transmission on the sidelink is semi - permanently scheduled, and the resource allocation information indicates multiple sets of resources for the set of transport blocks to be transmitted on the sidelink.

27. The UE according to claim 26, wherein at least one of the plurality of uplink feedback resources is configured to carry an acknowledgement or release feedback.

28. The UE according to claim 27, wherein the at least one processor is further configured to cause the UE to, in response to detecting an acknowledgement sidelink feedback on a sidelink feedback resource associated with the current transmission of the transport block, determine whether there is another transport block to be transmitted on the sidelink; and in response to a determination that there is another transport block to be transmitted on the sidelink, transmit the acknowledgement feedback on an uplink feedback resource associated with the current transmission of the transport block.

29. The UE according to claim 27, wherein the at least one processor is further configured to cause the UE to, in response to detecting an acknowledgement sidelink feedback on a sidelink feedback resource associated with the current transmission of the transport block, determine whether there is another transport block to be transmitted on the sidelink; and in response to a determination that there is no transport block to be transmitted on the sidelink, transmit the release feedback on an uplink feedback resource in the multiple sets of resources.

30. The UE according to claim 26, wherein the plurality of uplink feedback resources in each set of resources further includes a last uplink feedback resource configured to carry only a release feedback in response to a last sidelink transmission of the corresponding transport block associated with the set of resources indicated by the resource allocation information.

31. The UE according to claim 18, wherein the at least one processor is further configured to cause the UE to transmit acknowledgement information confirming receipt of the resource allocation information.

32. A base station, comprising: at least one memory; and at least one processor, coupled to the at least one memory and configured to cause the base station to: determine resource allocation information indicating at least one set of resources, wherein each set of resources is associated with a transport block in a set of transport blocks to be transmitted on a sidelink, and wherein each set of resources includes: a plurality of sidelink transmission resources, each sidelink transmission resource being configured to carry a sidelink transmission of the transport block; a plurality of sidelink feedback resources, each sidelink feedback resource being configured to carry sidelink feedback information in response to the sidelink transmission of the transport block; and a plurality of uplink feedback resources, at least one of the plurality of uplink feedback resources being configured to carry uplink feedback information in response to the sidelink transmission of the transport block only when the sidelink feedback information indicates that the transport block has been successfully decoded; and transmit the determined resource allocation information by indicating each resource in the at least one set of resources prior to the sidelink transmission of the transport block.

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