WO2022061816A1

WO2022061816A1 - Methods and apparatus for sidelink information indication

Info

Publication number: WO2022061816A1
Application number: PCT/CN2020/118144
Authority: WO
Inventors: Xiaodong Yu; Zhennian SUN; Jing HAN; Haipeng Lei
Original assignee: Lenovo Beijing Ltd
Current assignee: Lenovo Beijing Ltd
Priority date: 2020-09-27
Filing date: 2020-09-27
Publication date: 2022-03-31
Anticipated expiration: 2023-03-27

Abstract

Embodiments of the present disclosure relate to methods and apparatus for sidelink information indication. According to an embodiment of the present disclosure, a method performed by a first user equipment (UE) for wireless communication may include: determining a state type of each resource in a set of time-frequency resources, wherein the state type is one of a preferred type, a not-preferred type, and an uncertain type; and transmitting, to a second UE, first indication information indicating the state type of each resource in the set of time-frequency resources.

Description

METHODS AND APPARATUS FOR SIDELINK INFORMATION INDICATION

TECHNICAL FIELD

Embodiments of the present disclosure are related to wireless communication technologies, and more particularly, related to methods and apparatuses for sidelink information indication.

BACKGROUND

For sidelink transmissions, there are two resource allocation modes: 1) mode 1: a base station (BS) indicates sidelink resource (s) to a user equipment (UE) for performing a sidelink transmission; and 2) mode 2: a UE autonomously selects sidelink resource (s) for performing a sidelink transmission from a resource pool which contains sidelink resource (s) configured by a BS or pre-configured in standards. A UE operating in mode 2 normally performs a sensing and resource selecting procedure to select and/or reserve resource (s) for sidelink transmission. It would be beneficial for the UE to take into account assistance information received from other UE(s) in its resource selection.

SUMMARY OF THE DISCLOSURE

Embodiments of the present disclosure provide at least improved sidelink information indication to assist sidelink resource selection.

According to some embodiments of the present disclosure, a method performed by a first UE for wireless communication may include: determining a state type of each resource in a set of time-frequency resources, wherein the state type is one of a preferred type, a not-preferred type, and an uncertain type; and transmitting, to a second UE, first indication information indicating the state type of each resource in the set of time-frequency resources.

In an embodiment of the present disclosure, each resource in the set of time-frequency resources may be associated with a slot in time domain and a subchannel in frequency domain. The preferred type and the not-preferred type can be determined based on a sensing result of the first UE or a network indication, and the uncertain type can be associated with a slot not sensed by the first UE.

In an embodiment of the present disclosure, the first indication information can be transmitted by higher layer signaling or physical layer signaling. The first indication information may include a matrix, and each element field in the matrix may indicate the state type of a corresponding resource in the set of time-frequency resources. Each element field in the matrix may include 2 bits. Alternatively, the first indication information may include a matrix and a transmission pattern of the first UE, each element field in the matrix may indicate whether a corresponding resource in the set of time-frequency resources is preferred or not, and each element field in the transmission pattern may indicate whether the first UE performs transmission or reception in a corresponding slot. Each element field in the matrix may include 1 bit, and each element field in the transmission pattern may include 1 bit.

In an embodiment of the present disclosure, the method performed by the first UE may further include transmitting second indication information indicating a start point of the set of time-frequency resources in time domain. The second indication information may include a bitmap code corresponding to a slot index. The second indication information may further include a time offset.

According to some embodiments of the present disclosure, a method performed by a second UE for wireless communication may include: receiving, from a first UE, first indication information indicating a state type of each resource in a set of time-frequency resources, wherein the state type is one of a preferred type, a not-preferred type, and an uncertain type; and performing resource selection based on at least one of a sensing result of the second UE and the first indication information.

In an embodiment of the present disclosure, each resource in the set of time-frequency resources may be associated with a slot in time domain and a subchannel in frequency domain.

In an embodiment of the present disclosure, the first indication information can be received by higher layer signaling or physical layer signaling. The first indication information may include a matrix, and each element field in the matrix may indicate the state type of a corresponding resource in the set of time-frequency resources. Each element field in the matrix may include 2 bits. Alternatively, the first indication information may include a matrix and a transmission pattern of the first UE, each element field in the matrix may indicate whether a corresponding resource in the set of time-frequency resources is preferred or not, and each element field in the transmission pattern may indicate whether the first UE performs transmission or reception in a corresponding slot. Each element field in the matrix may include 1 bit, and each element field in the transmission pattern may include 1 bit.

In an embodiment of the present disclosure, the method performed by the second UE may further include receiving second indication information indicating a start point of the set of time-frequency resources in time domain. The second indication information may include a bitmap code corresponding to a slot index. The second indication information may further include a time offset.

In an embodiment of the present disclosure, performing resource selection based on at least one of a sensing result of the second UE and the first indication information may include identifying at least one first candidate resource in a resource selection window based on the sensing result of the second UE and the preferred type of resource indicated by the first indication information. Performing resource selection based on at least one of a sensing result of the second UE and the first indication information may further include identifying at least one second candidate resource in the resource selection window based on the uncertain type of resource indicated by the first indication information when a ratio of a number of the at least one first candidate resource to a total number of resources in the resource selection window is less than a configured or pre-configured threshold.

According to other embodiments of the present disclosure, an apparatus may include: at least one non-transitory computer-readable medium having stored thereon computer executable instructions; at least one receiving circuitry; at least one transmitting circuitry; and at least one processor coupled to the at least one non-transitory computer-readable medium, the at least one receiving circuitry and the at least one transmitting circuitry. The computer executable instructions may cause the at least processor to implement a method according to any embodiment of the present disclosure.

The details of one or more examples are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to describe the manner in which advantages and features of the present disclosure can be obtained, a description of the present disclosure is rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. These drawings depict only exemplary embodiments of the present disclosure and are not therefore intended to limit the scope of the present disclosure.

FIG. 1 illustrates an exemplary schematic diagram of a wireless communication system according to some embodiments of the present disclosure;

FIG. 2 illustrates a timeline of an exemplary sensing and resource selecting procedure according to some embodiments of the present disclosure;

FIG. 3 illustrates a flow chart of an exemplary method for sidelink information indication according to some embodiments of the present disclosure;

FIG. 4 illustrates an exemplary set of time-frequency resources each marked with a respective state type according to some embodiments of the present disclosure;

FIG. 5 illustrates an exemplary block diagram of an apparatus according to some embodiments of the present disclosure; and

FIG. 6 illustrates an exemplary block diagram of another apparatus according to some embodiments of the present disclosure.

DETAILED DESCRIPTION

The detailed description of the appended 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 may be practiced. It is to be understood that the same or equivalent functions may be accomplished by different embodiments that are intended to be encompassed within the spirit and scope of the present disclosure.

In the following description, numerous specific details are provided, such as examples of programming, software modules, network transactions, database structures, hardware modules, hardware circuits, etc., to provide a thorough understanding of embodiments. One skilled in the relevant art will recognize, however, that embodiments may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of an embodiment.

Reference will now be made in detail to some embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. To facilitate understanding, embodiments are provided under specific network architecture and new service scenarios, such as 3rd Generation Partnership Project (3GPP) 5G, 3GPP Long Term Evolution (LTE) and so on. Persons skilled in the art know very well that, with the development of network architecture and new service scenarios, the embodiments in the present disclosure are also applicable to similar technical problems; and moreover, the terminologies recited in the present disclosure may change, which should not affect the principle of the present disclosure.

FIG. 1 illustrates an exemplary schematic diagram of a wireless communication system 100 according to some embodiments of the present disclosure.

As shown in FIG. 1, a wireless communication system 100 may include at least one base station (BS) , e.g., BS 120, and at least one UE 110, e.g., UE 110a, UE 110b, and UE 110c. Although a specific number of UEs 110 and one BS 120 are depicted in FIG. 1, it is contemplated that wireless communication system 100 may also include more BSs and more or fewer UEs in and outside of the coverage of the BSs.

The wireless communication system 100 can be compatible with any type of network that is capable of sending and receiving wireless communication signals. For example, the wireless communication system 100 can be compatible with a wireless communication network, a cellular telephone network, a time division multiple access (TDMA) -based network, a code division multiple access (CDMA) -based network, an orthogonal frequency division multiple access (OFDMA) -based network, an LTE network, a 3GPP-based network, a 3GPP 5G network, a satellite communications network, a high altitude platform network, and/or other communications networks.

The UEs 110 and the BS 120 may support communication based on, for example, 3G, LTE, LTE-advanced (LTE-A) , new radio (NR) , or other suitable protocol (s) . In some embodiments of the present disclosure, the BS 120 may also be referred to as an access point, an access terminal, a base, a macro cell, a node-B, an enhanced node B (eNB) , a gNB, a home node-B, a relay node, or a device, or described using other terminology used in the art. The UE 110a, UE 110b, or UE 110c may include, for example, but is not limited to, a computing device, a wearable device, a mobile device, an IoT (Internet of Things) device, a vehicle, etc. Moreover, the UE 110a, UE 110b, or UE 110c may be referred to as a subscriber unit, a mobile, a mobile station, a user, a terminal, a mobile terminal, a wireless terminal, a subscriber station, a user terminal, or a device, or described using other terminology used in the art. Persons skilled in the art should understand that as technology develops and advances, the terminologies described in the present disclosure may change, but should not affect or limit the principles and spirit of the present disclosure.

The BS 120 may define one or more cells, and each cell may have a coverage area 130. In the exemplary wireless communication system 100, some UEs (e.g., UE 110a and UE 110b) are within the coverage of the BS 120, which may not be a specific BS 120 shown in FIG. 1 and can be any one of the BSs 120 in a wireless communication system, and some UEs (e.g., UE 110c) are outside of the coverage of the BS 120. For example, in the case that the wireless communication system includes two BSs 120, a UE 110 being within the coverage of any one of the two BSs 120 means that the UE 110 is within the coverage of a BS 120 (i.e., in-coverage) in the wireless communication system; and a UE 110 being outside of the coverage of both BSs 120 means that UE 110 is outside of the coverage of a BS 120 (i.e., out-of-coverage) in the wireless communication system.

Still referring to FIG. 1, the UE 110a and UE 110b may communicate with the BS 120 via, for example, a Uu link (denoted by dotted arrow in FIG. 1) . The UE 110a, UE 110b, and UE 110c may communicate with each other (e.g., UE 110a may communicate with UE 110b, or UE 110a may communicate with UE 110c) via a sidelink (denoted by solid arrow in FIG. 1) , and may form a UE group. During a sidelink communication, a transmitting UE (hereinafter referred to as a “Tx UE” ) may transmit signaling, data, or both to a receiving UE (hereinafter referred to as an “Rx UE”) . For example, referring to FIG. 1, a Tx UE (e.g., UE 110a) may transmit data to an Rx UE (e.g., UE 110b or UE 110c) .

As described above, there are two resource allocation modes for sidelink transmissions. In mode 1, sidelink resource (s) is (are) assigned by a network (e.g., by a BS) , for example, via dynamic scheduling or configured grant. In mode 2, sidelink resource (s) is (are) selected from a configured or pre-configured resource pool by a Tx UE itself. Either for mode 1 or for mode 2, after sidelink resource (s) to be used or reserved is (are) determined, the Tx UE may transmit sidelink control information (SCI) on a physical sidelink control channel (PSCCH) which indicates the time-frequency resources in which the Tx UE transmits a physical sidelink shared channel (PSSCH) . These SCI transmissions can be detected and used by sensing UE (s) to maintain a record of which resources have been used or reserved by others UEs in the recent past, such that the sensing UE (s) can avoid using the sidelink resource (s) indicated by the SCI, which the sensing UE (s) may deem unavailable resource (s) , to avoid collision or interference.

A Tx UE operating in mode 2 (also referred to as a “mode 2 UE” ) normally performs a sensing and resource selecting procedure before performing a sidelink transmission to an Rx UE. FIG. 2 illustrates a timeline of an exemplary sensing and resource selecting procedure according to some embodiments of the present disclosure.

As shown in FIG. 2, when a resource selection for a mode 2 UE is triggered (e.g., by traffic arrival or a re-selection trigger) , the mode 2 UE may consider a sensing window T0 which starts a configured or preconfigured time in the past and finishes shortly (e.g., a first processing period T1) before the trigger time Tr. The mode 2 UE may detect SCI transmission (s) transmitted by surrounding UE (s) in the slots of the sensing window. The mode 2 UE may process the sensing result (s) obtained in the sensing window in the first processing period T1. The sensing window can be either 1100ms or 100ms wide, with the intention that the 100ms option is particularly for aperiodic traffic, and the 1100ms option is particularly for periodic traffic. The mode 2 UE may also measure the sidelink (SL) reference signal receiving power (RSRP) in the slots of the sensing window. The SL-RSRP may imply the level of interference which would be caused and experienced if the mode 2 UE were to perform transmission in the slots. In NR vehicle-to-everything (V2X) communication, SL-RSRP is a configurable or pre-configurable measurement of either PSSCH-RSRP or PSCCH-RSRP.

Next, the mode 2 UE may select resource (s) for its transmission (s) or retransmission (s) from within a resource selection window T3. The selection window T3 starts shortly (e.g., a second processing period T2) after the trigger time Tr and T2+T3 cannot be longer than the remaining latency budget of the packet to be transmitted. In the second processing period T2, the mode 2 UE may perform any necessary processing that should be performed before a sidelink transmission, including determining a length of the selection window T3. The mode 2 UE may autonomously select time-frequency resource (s) within the selection window T3 and perform sidelink transmission (s) or re-transmission (s) using the selected resource (s) , e.g.,

resources

200, 201, and 202. Resources in the selection window which are reserved for other UE (s) (e.g., indicated by SCI detected in the sensing window) and have SL-RSRP above a threshold can be excluded from being candidates to be selected by the mode 2 UE. The threshold can be set according to the priorities of the traffic of the mode 2 UE and that of the other UE (s) . Thus, a higher priority transmission from the mode 2 UE can occupy resources which are reserved by the other UE (s) with sufficiently low SL-RSRP and sufficiently lower priority traffic.

In the example shown in FIG. 2, the mode 2 UE may select the

resources

200, 201, and 202 and transmit SCI on the resource 200, and the SCI may indicate resource (s) (e.g., resources 201 and 202) to be reserved for the mode 2 UE. It should be understood that the durations of T0, T1, T2, and T3 shown in FIG. 2 are provided only for illustrative purposes, and should not be construed as limits to the embodiments of the present disclosure.

Inter-UE coordination can be applied to improve resource selection for mode 2 UEs. In some implementations, a mode 2 UE may obtain more comprehensive information on resource allocation and reservation by receiving assistance information from one or more other UEs, and take the assistance information into account when selecting resource (s) for sidelink transmission.

FIG. 3 illustrates a flow chart of an exemplary method for sidelink information indication according to some embodiments of the present disclosure. The method can be performed by UE-A and UE-B. UE-A and UE-B can be any UE described herein (e.g., the

UE

110a, 110b, or 110c in FIG. 1) . In particular, UE-B may operate in mode 2.

As shown in FIG. 3, the UE-A may determine a state type of each resource in a set of time-frequency resources, at step 302. The time-frequency resources can be a resource pool. Each resource in the set of time-frequency resources may be associated with a number of slots in time domain and a number of subchannels in frequency domain. The number of slots and/or the number of subchannels can be configured or pre-configured per set of resources or per resource pool. For example, each resource may be associated with a slot in time domain and one or more subchannels in frequency domain. The subchannel may include multiple continuous physical resource blocks (PRBs) in the frequency domain. According to some embodiments of the present disclosure, the state type of a resource may be one of the following types: (1) preferred type, (2) not-preferred type, or (3) uncertain type.

The preferred type of resource may refer to a resource that is preferred for the UE-B’s sidelink transmission (e.g., to UE-A or other UE (s) ) . In an embodiment of the present disclosure, the preferred type of resource can be determined based on a network indication to the UE-A (e.g., when the UE-A operates in mode 1) or a sensing result of the UE-A (e.g., when the UE-A operates in mode 2) . It may include, for example, a resource that is not reserved by other UE (s) based on the SCI detection at the UE-A side, or a resource with less interference based on the energy (e.g., SL-RSRP) detection at the UE-A side.

The not-preferred type of resource may refer to a resource that is not preferred (i.e., a resource with a problem) for the UE-B’s sidelink transmission (e.g., to UE-A or other UE (s) ) . In an embodiment of the present disclosure, the not-preferred type of resource can be determined based on a network indication to the UE-A (e.g., when the UE-A operates in mode 1) or a sensing result of the UE-A (e.g., when the UE-A operates in mode 2) . It may include, for example, a resource that is reserved by other UE (s) based on the SCI detection at the UE-A side, or a resource with strong interference based on the energy (e.g., SL-RSRP) detection at the UE-A side.

The uncertain type of resource may refer to a resource that the UE-A cannot determine whether it is reserved by other UE (s) because it is associated with a slot not indicated by a network indication to the UE-A (e.g., when the UE-A operates in mode 1) or not sensed by the UE-A (e.g., when the UE-A operates in mode 2) . For example, the UE-A may perform sidelink transmission in a slot within its sensing window (e.g., T0 in FIG. 2) , and cannot perform reception or sensing in this slot due to half duplexing at the UE-A. As a result, the UE-A cannot know whether any other UE transmits SCI in the slot or whether subsequent resource (s) associated with the slot (e.g., resource (s) in a pre-defined period) is (are) reserved by other UE (s) . The UE-A cannot indicate the subsequent resource (s) as the preferred resource (s) because, based on the current sensing mechanism, the UE-A should deem this kind of resource (s) unavailable and exclude it to avoid potential collision or interference. On the other hand, the UE-A cannot indicate the subsequent resource (s) as the not-preferred resource (s) (i.e., resource (s) with a problem) because it is possible that the subsequent resource (s) may not be reserved by other UE (s) and can be used as candidate (s) for the UE-B’s sidelink transmission. The uncertain type of resources can be used to increase the UE-B’s available resources under certain conditions.

After determining the state type of each resource in the set of time-frequency resources, the UE-A may transmit, to the UE-B, first indication information indicating the state type of each resource in the set of time-frequency resources, at step 304. According to some embodiments of the present disclosure, the first indication information can be transmitted by higher layer signaling. According to other embodiments of the present disclosure, the first indication information can be transmitted by physical layer signaling, e.g., SCI or a second stage of SCI.

According to other embodiments of the present disclosure, the first indication information indicating the state type of each resource in the set of time-frequency resources may include a matrix, wherein each element field in the matrix may indicate the state type of a corresponding resource in the set of time-frequency resources.

FIG. 4 illustrates an exemplary set of time-frequency resources each marked with a respective state type according to some embodiments of the present disclosure. The exemplary set of time-frequency resources spans 10 slots and 8 subchannels. As an example, the first indication information may include the following matrix to indicate the state type of each resource in the set of time-frequency resources as shown in FIG. 4.

{

10, 01, 10, 00, 01, 01, 10, 10, 00, 00

10, 01, 10, 00, 00, 01, 10, 10, 00, 00

10, 01, 10, 00, 01, 01, 10, 10, 01, 01

10, 01, 10, 00, 00, 01, 10, 10, 01, 01

10, 00, 10, 00, 01, 01, 10, 10, 01, 00

10, 01, 10, 00, 01, 01, 10, 10, 01, 00

}

In the above matrix, each column corresponds to a slot, and each row corresponds to a subchannel. Each element field (i.e., the intersection of a column and a row) of the matrix may include 2 bits, wherein 00 may represent the preferred type, 01 may represent the not-preferred type, 10 may represent the uncertain type, and 11 may represent a reserved state (not used in this example) . It should be understood that the above matrix is provided only for illustrative purposes, and should not be construed as limits to the embodiments of the present disclosure. In some embodiments of the present disclosure, a row of the matrix may correspond to a set of subchannels.

According to other embodiments of the present disclosure, the first indication information indicating the state type of each resource in the set of time-frequency resources may include a matrix and a transmission pattern of the UE-A, wherein each element field in the matrix may indicate whether a corresponding resource in the set of time-frequency resources is preferred or not, and each element field in the transmission pattern may indicate whether the UE-A performs transmission or reception in a corresponding slot.

The matrix used in such embodiments may not indicate the uncertain type of resources. The uncertain type of resources can be pre-defined as preferred. As such, the element field in the matrix can use a single bit to indicate whether the corresponding resource is preferred (including the preferred type and the uncertain type) or not. Alternatively, the uncertain type of resources can be pre-defined as not-preferred.

For example, the following matrix can be used to indicate the set of time-frequency resources as shown in FIG. 4.

{

1, 0, 1, 1, 0, 0, 1, 1, 1, 1

1, 0, 1, 1, 1, 0, 1, 1, 1, 1

1, 0, 1, 1, 0, 0, 1, 1, 0, 0

1, 0, 1, 1, 1, 0, 1, 1, 0, 0

1, 1, 1, 1, 0, 0, 1, 1, 0, 1

1, 0, 1, 1, 0, 0, 1, 1, 0, 1

}

In the above matrix, each column corresponds to a slot, and each row corresponds to a subchannel. Each element field (i.e., the intersection of a column and a row) of the matrix may include 1 bit, wherein 1 may represent both the preferred type and the uncertain type, and 0 may represent the not-preferred type. It should be understood that the above matrix is provided only for illustrative purposes, and should not be construed as limits to the embodiments of the present disclosure. In some embodiments of the present disclosure, a row of the matrix may correspond to a set of subchannels.

The transmission pattern of the UE-A can be used in conjunction with the matrix to determine the uncertain type of resources. For the example shown in FIG. 4, the transmission pattern of the UE-A can be represented as [1, 0, 1, 0, 0, 0, 1, 1, 0, 0] , wherein 1 represents that the UE-A performs “transmission” in a corresponding slot (i.e., not performing sensing in that slot) , and 0 represents that the UE-A performs “reception” in the corresponding slot (i.e., performing sensing in that slot) . When a slot is indicated as “1” in the transmission pattern, the resources in the set of time-frequency resources associated with that slot can be determined as the uncertain type of resources. Based on the above transmission pattern of the UE-A, it can be determined that the resources in the first, third, seventh, and eighth slots are the uncertain type of resources. Then, the other resources represented as 1 in the above matrix can be determined as the preferred type, and the resources represented as 0 in the above matrix can be determined as the not-preferred type. That is, the combination of the matrix and the transmission pattern of the UE-A can indicate the three types of resources to the UE-B. It should be understood that the above transmission pattern is provided only for illustrative purposes, and should not be construed as limits to the embodiments of the present disclosure.

According to some embodiments of the present disclosure, the UE-A may additionally transmit second indication information to the UE-B, at step 306. The second indication information may indicate a start point of the set of time-frequency resources in time domain (e.g., the start slot index in a certain time) . The second indication information can be transmitted by higher layer signaling or physical layer signaling. Although shown as two steps in FIG. 4, the first indication information and the second indication information can be transmitted in a single signaling.

In an embodiment of the present disclosure, the second indication information may include a bitmap code corresponding to the start slot index. The following Table 1 provides an exemplary mapping between the bitmap code and the start slot index, which includes slot#0 to slot#9 in 10 milliseconds (ms) . For example, the second indication information with a field length of 4bits can be represented as 0101, which indicates that the set of time-frequency resources indicated by the first indication information starts at slot#5.

Table 1

In other embodiments of the present disclosure, the field length of second indication information may be 10 bits or 14 bits when the bitmap represents 1024 slots (e.g., start slot index from 0 to 1023) or 10240 slots (e.g., start slot index from 0 to 10239) , respectively.

When 15kHz sub-carrier spacing is applied, the time length of each slot is 1 millisecond (ms) . The bitmap code corresponding to the start slot index can also represent from which millisecond in absolute time the set of time-frequency resources starts. When 30kHz, 60kHz, or 120kHz sub-carrier spacing is applied, the time length of each slot is 0.5ms, 0.25ms, or 0.125ms. For such cases, in addition to the bitmap code corresponding to the millisecond, the second indication information may further include an additional field or indication to indicate a time offset to represent the start point in absolute time. The following Table 2 provides examples for the additional field or indication. For example, for 30kHz sub-carrier spacing, the second indication information can be represented as 0101 and the additional field or indication can be represented as 0, which indicates that the set of time-frequency resources indicated by the first indication information starts at the eleventh slot of 10ms (i.e., the eleventh slot of 20 slots within 10ms) ; the second indication information can be represented as 0101 and the additional field or indication can be represented as 1, which indicates that the set of time-frequency resources indicated by the first indication information starts at the twelfth slot of 10ms (i.e., the twelfth slot of 20 slots within 10ms) .

Table 2

After receiving the first indication information (or both the first and second indication information) , the UE-B may perform resource selection based on at least one of a sensing result of the UE-B and the first indication information, at step 308.

According to some embodiments of the present disclosure, in step 308, the UE-B may first identify at least one first candidate resource in a resource selection window based on the sensing result of the UE-B and the preferred type of resource (s) indicated by the first indication information received from the UE-A. For example, the UE-B may select the at least one first candidate resource from both the resources determined by the UE-B as preferred based on its sensing procedure and the preferred type of resource (s) indicated by the first indication information. When the number of the at least one first candidate resource is not sufficient, e.g., a ratio of the number of the at least one first candidate resource to a total number of resources in the resource selection window is less than a configured or pre-configured threshold, wherein the threshold can be configured or pre-configured per resource pool, the UE-B may further identify at least one second candidate resource in the resource selection window based on the uncertain type of resource (s) indicated by the first indication information. By using the uncertain type of resource (s) , the UE-B may identify a sufficient amount of candidate resources from which the higher layer of the UE-B can randomly select for sidelink transmission. It is contemplated that the UE-B may receive first indication information from one or more other UE (s) and take all the first indication information into account when perform resource selection.

According to other embodiments of the present disclosure, the UE-A may ensure that a ratio of the number of the preferred type of resources to the total number of resources is not smaller than a configured or pre-configured threshold, e.g., by increasing a threshold used in the energy (e.g., SL-RSRP) detection at the UE-A side.

FIG. 5 illustrates an exemplary block diagram of an apparatus 500 according to some embodiments of the present disclosure. In some embodiments of the present disclosure, the apparatus 500 may be or include a UE (e.g., UE-A) or other devices having similar functionality. In some embodiments, the apparatus 500 can be configured to perform the method illustrated in FIG. 3.

As shown in FIG. 5, the apparatus 500 may include at least one receiving circuitry 502, at least one transmitting circuitry 504, at least one non-transitory computer-readable medium 506, and at least one processor 508 coupled to the at least one receiving circuitry 502, the at least one transmitting circuitry 504, the at least one non-transitory computer-readable medium 506. While shown to be coupled to each other via the at least one processor 508 in the example of FIG. 5, the at least one receiving circuitry 502, the at least one transmitting circuitry 504, the at least one non-transitory computer-readable medium 506, and the at least one processor 508 may be coupled to one another in various arrangements. For example, the at least one receiving circuitry 502, the at least one transmitting circuitry 504, the at least one non-transitory computer-readable medium 506, and the at least one processor 508 may be coupled to each other via one or more local buses (not shown for simplicity) .

Although in FIG. 5, elements such as receiving circuitry 502, transmitting circuitry 504, non-transitory computer-readable medium 506, and processor 508 are described in the singular, the plural is contemplated unless limitation to the singular is explicitly stated. In some embodiments of the present disclosure, the at least one receiving circuitry 502 and the at least one transmitting circuitry 504 may be combined into a single device, such as a transceiver. In certain embodiments of the present disclosure, the apparatus 500 may further include an input device, a memory, and/or other components.

In some embodiments of the present disclosure, the at least one non-transitory computer-readable medium 506 may have stored thereon computer-executable instructions which are programmed to cause the at least one processor 508 to implement the steps of the methods according to embodiments of the present disclosure, for example as described in view of FIG. 3, with the at least one receiving circuitry 502 and the at least one transmitting circuitry 504. For example, when executed, the instructions may cause the at least one processor 508 to determine a state type of each resource in a set of time-frequency resources, wherein the state type is one of a preferred type, a not-preferred type, and an uncertain type. The instructions may further cause the at least one processor 508 to transmit to a second UE (e.g., UE-B) , with the at least one transmitting circuitry 504, first indication information indicating the state type of each resource in the set of time-frequency resources.

FIG. 6 illustrates an exemplary block diagram of an apparatus 600 according to some embodiments of the present disclosure. In some embodiments of the present disclosure, the apparatus 600 may be or include a UE (e.g., UE-B) or other devices having similar functionality. In some embodiments, the apparatus 600 can be configured to perform the method illustrated in FIG. 3.

As shown in FIG. 6, the apparatus 600 may include at least one receiving circuitry 602, at least one transmitting circuitry 604, at least one non-transitory computer-readable medium 606, and at least one processor 608 coupled to the at least one receiving circuitry 602, the at least one transmitting circuitry 604, the at least one non-transitory computer-readable medium 606. While shown to be coupled to each other via the at least one processor 608 in the example of FIG. 6, the at least one receiving circuitry 602, the at least one transmitting circuitry 604, the at least one non-transitory computer-readable medium 606, and the at least one processor 608 may be coupled to one another in various arrangements. For example, the at least one receiving circuitry 602, the at least one transmitting circuitry 604, the at least one non-transitory computer-readable medium 606, and the at least one processor 608 may be coupled to each other via one or more local buses (not shown for simplicity) .

Although in FIG. 6, elements such as receiving circuitry 602, transmitting circuitry 604, non-transitory computer-readable medium 606, and processor 608 are described in the singular, the plural is contemplated unless limitation to the singular is explicitly stated. In some embodiments of the present disclosure, the at least one receiving circuitry 602 and the at least one transmitting circuitry 604 may be combined into a single device, such as a transceiver. In certain embodiments of the present disclosure, the apparatus 600 may further include an input device, a memory, and/or other components.

In some embodiments of the present disclosure, the at least one non-transitory computer-readable medium 606 may have stored thereon computer-executable instructions which are programmed to cause the at least one processor 608 to implement the steps of the methods according to embodiments of the present disclosure, for example as described in view of FIG. 3, with the at least one receiving circuitry 602 and the at least one transmitting circuitry 604. For example, when executed, the instructions may cause the at least one processor 608 to receive from a first UE (e.g., UE-A) , with the at least one receiving circuitry 602, first indication information indicating a state type of each resource in a set of time-frequency resources, wherein the state type is one of a preferred type, a not-preferred type, and an uncertain type. The instructions may further cause the at least one processor 608 to perform resource selection based on at least one of a sensing result of the apparatus 600 and the first indication information.

As will be appreciated by one skilled in the art, aspects of the embodiments may be embodied as a system, apparatus, method, or a program product. Accordingly, embodiments may take the form of an all-hardware embodiment, an all-software embodiment (including firmware, resident software, micro-code, etc. ) or an embodiment combining software and hardware aspects.

For example, the disclosed embodiments may be implemented as a hardware circuit comprising custom very-large-scale integration (VLSI) circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. The disclosed embodiments may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices, or the like. As another example, the disclosed embodiments may include one or more physical or logical blocks of executable code which may, for instance, be organized as an object, procedure, or function.

Furthermore, embodiments may take the form of a program product embodied in one or more computer readable storage devices storing machine readable code, computer readable code, or program code. The storage devices may be tangible, non-transitory, or non-transmission. The storage devices may not embody signals. In a certain embodiment, the storage devices only employ signals for accessing code.

Any combination of one or more computer readable medium may be utilized. The computer readable medium may be a computer readable storage medium. The computer readable storage medium may be a storage device storing the code. The storage device may be, for example, but is not limited to being, an electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing.

A non-exhaustive list of more specific examples of the storage device may include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random-access memory (RAM) , a read-only memory (ROM) , an erasable programmable read-only memory (EPROM or Flash memory) , a portable compact disc read-only memory (CD-ROM) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device.

Furthermore, the described features, structures, or characteristics of the embodiments may be combined in any suitable manner. While this disclosure has been described with specific embodiments thereof, it is evident that many alternatives, modifications, and variations may be apparent to those skilled in the art. For example, various components of the embodiments may be interchanged, added, or substituted in the other embodiments. Also, all of the elements of each figure are not necessary for operation of the disclosed embodiments. For example, those having ordinary skills in the art would be enabled to make and use the teachings of the disclosure by simply employing the elements of the independent claims. Accordingly, embodiments of the disclosure as set forth herein are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the disclosure.

Reference throughout this specification to “one embodiment, ” “an embodiment, ” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment, ” “in an embodiment, ” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment, but mean “one or more but not all embodiments” unless expressly specified otherwise. In this document, the terms “includes, ” “including, ” or any other variation 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 proceeded by “a, ” “an, ” or the like does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that includes the element. Also, the term “another” is defined as at least a second or more. The term “having” and the like, as used herein, are defined as “including. ”

Claims

A method performed by a first user equipment (UE) for wireless communication, comprising:

determining a state type of each resource in a set of time-frequency resources, wherein the state type is one of a preferred type, a not-preferred type, and an uncertain type; and

transmitting, to a second UE, first indication information indicating the state type of each resource in the set of time-frequency resources.
The method of claim 1, wherein the preferred type and the not-preferred type are determined based on a sensing result of the first UE or a network indication, and the uncertain type is associated with a slot not sensed by the first UE.
The method of claim 1, wherein the first indication information is transmitted by higher layer signaling or physical layer signaling.
The method of claim 1, wherein each resource in the set of time-frequency resources is associated with a slot in time domain and a subchannel in frequency domain.
The method of claim 1, wherein the first indication information comprises a matrix, and each element field in the matrix indicates the state type of a corresponding resource in the set of time-frequency resources.
The method of claim 5, wherein each element field in the matrix comprises 2 bits.
The method of claim 1, wherein the first indication information comprises a matrix and a transmission pattern of the first UE, each element field in the matrix indicates whether a corresponding resource in the set of time-frequency resources is preferred or not, and each element field in the transmission pattern indicates whether the first UE performs transmission or reception in a corresponding slot.
The method of claim 7, wherein each element field in the matrix comprises 1 bit, and each element field in the transmission pattern comprises 1 bit.
The method of claim 1, further comprising transmitting second indication information indicating a start point of the set of time-frequency resources in time domain.
The method of claim 9, wherein the second indication information comprises a bitmap code corresponding to a slot index.
The method of claim 10, wherein the second indication information further comprises a time offset.
A method performed by a second user equipment (UE) for wireless communication, comprising:

receiving, from a first UE, first indication information indicating a state type of each resource in a set of time-frequency resources, wherein the state type is one of a preferred type, a not-preferred type, and an uncertain type; and

performing resource selection based on at least one of a sensing result of the second UE and the first indication information.
The method of claim 12, wherein performing resource selection based on at least one of a sensing result of the second UE and the first indication information comprises identifying at least one first candidate resource in a resource selection window based on the sensing result of the second UE and the preferred type of resource indicated by the first indication information.
The method of claim 13, wherein performing resource selection based on at least one of a sensing result of the second UE and the first indication information further comprises identifying at least one second candidate resource in the resource selection window based on the uncertain type of resource indicated by the first indication information when a ratio of a number of the at least one first candidate resource to a total number of resources in the resource selection window is less than a configured or pre-configured threshold.
An apparatus, comprising:

at least one non-transitory computer-readable medium having stored thereon computer-executable instructions;

at least one receiving circuitry;

at least one transmitting circuitry; and

at least one processor coupled to the at least one non-transitory computer-readable medium, the at least one receiving circuitry and the at least one transmitting circuitry,

wherein the computer-executable instructions cause the at least one processor to implement the method according to any one of claims 1-14.