WO2024093055A1

WO2024093055A1 - Terminal device and method for sidelink communications

Info

Publication number: WO2024093055A1
Application number: PCT/CN2023/078084
Authority: WO
Inventors: Zhennian SUN; Haipeng Lei; Xiaodong Yu; Xin Guo
Original assignee: Lenovo (Beijing) Limited
Priority date: 2023-02-24
Filing date: 2023-02-24
Publication date: 2024-05-10

Abstract

Embodiments of the present disclosure relate to a solution for sidelink communications. In one aspect of the solution, a terminal device determines, for a first sidelink transmission, a first transmission resource associated with a first feedback resource, based on information on a second feedback resource associated with a second transmission resource determined for a second sidelink transmission to be transmitted. Moreover, the terminal device transmits the first sidelink transmission on the first transmission resource. In this way, it is possible to avoid resource waste and improve transmission efficiency.

Description

TERMINAL DEVICE AND METHOD FOR SIDELINK COMMUNICATIONS

FIELD

Embodiments of the present disclosure generally relate to the field of communication, and in particular to a terminal device and a method, and a non-transitory computer readable medium for sidelink communications.

BACKGROUND

In telecommunications networks, such as long term evolution (LTE) networks or new radio (NR) networks, sidelink communications between user equipment (UEs) over a proximity services (ProSe) Communication 5 (PC5) wireless interface may be supported. In sidelink communications, UEs may communicate with each other directly via a PC5 wireless interface on a sidelink channel. Further, sidelink communications may obtain a plurality of benefits, such as coverage extension, service reliability enhancement, and potential low latency.

As discussed in the third generation partnership project (3GPP) release 16 (Rel-16) , there are two types of sidelink resource allocation, called sidelink resource allocation mode 1 and sidelink resource allocation mode 2. With the sidelink resource allocation mode 1, the resources for sidelink transmissions are allocated by the network. With the sidelink resource allocation mode 2, the resources for sidelink transmissions are determined by the transmitting (TX) UE based on its sensing. However, there are still some open problems, for example, for resource selection in sidelink communications that will be studied in the near future.

SUMMARY

In general, embodiments of the present disclosure provide a solution for resource selection in sidelink communications.

In a first aspect, there is provided a terminal device. The terminal device comprises a processor and a transceiver coupled to the processor. The processor is configured to determine, for a first sidelink transmission, a first transmission resource associated with a first feedback resource, based on information on a second feedback resource associated with a second transmission resource determined for a second sidelink transmission to be transmitted; and transmit, via the transceiver, the first sidelink transmission on the first transmission resource.

In a second aspect, there is provided a method performed by a terminal device. The method comprises determining, for a first sidelink transmission, a first transmission resource associated with a first feedback resource, based on information on a second feedback resource associated with a second transmission resource determined for a second sidelink transmission to be transmitted; and transmitting the first sidelink transmission on the first transmission resource.

In a third aspect, there is provided a non-transitory computer readable medium. The non-transitory computer readable medium having program instructions stored thereon. The program instructions, when executed by an apparatus, causing the apparatus at least to: determine, for a first sidelink transmission, a first transmission resource associated with a first feedback resource, based on information on a second feedback resource associated with a second transmission resource determined for a second sidelink transmission to be transmitted; and transmit the first sidelink transmission on the first transmission resource.

It is to be understood that the summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Some embodiments will now be described with reference to the accompanying drawings, in which:

FIG. 1A illustrates a schematic diagram of a communication environment in which some embodiments of the present disclosure can be implemented;

FIG. 1B illustrates an example communication scenario in according to some embodiments of the present disclosure;

FIG. 2 illustrates a flowchart of an example method for communication in accordance with some embodiments of the present disclosure;

FIG. 3 illustrates a schematic diagram of resource exclusion during a resource selection window in accordance with some embodiments of the present disclosure; and

FIG. 4 illustrates a simplified block diagram of an apparatus that is suitable for implementing embodiments of the present disclosure.

Throughout the drawings, the same or similar reference numerals represent the same or similar elements.

DETAILED DESCRIPTION

Principles of the present disclosure will now be described with reference to some embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. The disclosure described herein may be implemented in various manners other than the ones described below.

In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

References in the present disclosure to “one embodiment, ” “an example embodiment, ” “an embodiment, ” “some embodiments, ” and the like indicate that the embodiment (s) described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment (s) . Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It shall be understood that although the terms “first” and “second” or the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, a first element could also be termed as a second element, and similarly, a second element could also be termed as a first element, without departing from the scope of embodiments. As used herein, the term “and/or” includes any and all combinations of one or more of the listed terms.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a” , “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” , “comprising” , “has” , “having” , “includes” and/or “including” , when used herein, specify the presence of stated features, elements, and/or components etc., but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof.

As used herein, the term “communication network” refers to a network following any suitable communication standards, such as, 5G NR, long term evolution (LTE) , LTE-advanced (LTE-A) , wideband code division multiple access (WCDMA) , high-speed packet access (HSPA) , narrow band internet of things (NB-IoT) , and so on. Further, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.75G, the third generation (3G) , the fourth generation (4G) , 4.5G, the fifth generation (5G) communication protocols, and/or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will also be future type communication technologies and systems in which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned systems.

As used herein, the term “network device” generally refers to a node in a communication network via which a terminal device can access the communication network and receive services therefrom. The network device may refer to a base station (BS) or an access point (AP) , for example, a node B (NodeB or NB) , a radio access network (RAN) node, an evolved NodeB (eNodeB or eNB) , a NR NB (also referred to as a gNB) , a Remote Radio Unit (RRU) , a radio header (RH) , an infrastructure device for a V2X (vehicle-to-everything) communication, a transmission and reception point (TRP) , a reception point (RP) , a remote radio head (RRH) , a relay, an integrated access and backhaul (IAB) node, a low power node such as a femto BS, a pico BS, and so forth, depending on the applied terminology and technology.

As used herein, the term “terminal device” generally refers to any end device that may be capable of wireless communications. By way of example rather than a limitation, a terminal device may also be referred to as a communication device, a user equipment (UE) , an end user device, a subscriber station (SS) , an unmanned aerial vehicle (UAV) , a portable subscriber station, a mobile station (MS) , or an access terminal (AT) . The terminal device may include, but is not limited to, a mobile phone, a cellular phone, a smart phone, a voice over IP (VoIP) phone, a wireless local loop phone, a tablet, a wearable terminal device, a personal digital assistant (PDA) , a portable computer, a desktop computer, an image capture terminal device such as a digital camera, a gaming terminal device, a music storage and playback appliance, a vehicle-mounted wireless terminal device, a wireless endpoint, a mobile station, laptop-embedded equipment (LEE) , laptop-mounted equipment (LME) , a USB dongle, a smart device, wireless customer-premises equipment (CPE) , an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD) , a vehicle, a drone, a medical device (for example, a remote surgery device) , an industrial device (for example, a robot and/or other wireless devices operating in an industrial and/or an automated processing chain contexts) , a consumer electronics device, a device operating on commercial and/or industrial wireless networks, and the like. In the following description, the terms: “terminal device, ” “communication device, ” “terminal, ” “user equipment” and “UE, ” may be used interchangeably.

As used herein, the term: “resource, ” “transmission resource, ” “resource block, ” “physical resource block, ” “uplink resource, ” “downlink resource, ” or “sidelink resource” may refer to any resource, for example, a resource in the time domain, a resource in the frequency domain, a resource in the space domain, a resource in code domain, or any other resource enabling a communication, and the like, used for performing a communication between a terminal device and a network device or between terminal devices. In the following, a resource in both frequency and time domains will be used as an example of a transmission resource for describing some embodiments of the present disclosure. It is noted that embodiments of the present disclosure equally apply to other resources in other domains.

As used herein, the term “sidelink transmission” generally refers to any transmission performed from one terminal device to another terminal device. The sidelink transmission may be used for transmitting any data or control information associated with sidelink communications, for example, sidelink data, sidelink control information, sidelink feedback information, or the like. As used herein, the term “sidelink channel” may generally refer to any channel used for sidelink communications, for example, Physical Sidelink Shared Channel (PSSCH) , Physical Sidelink Control Channel (PSCCH) , Physical Sidelink Discovery Channel (PSDCH) , Physical Sidelink Broadcast Channel (PSBCH) , Physical Sidelink Feedback Channel (PSFCH) , and other existing or future sidelink channels.

As mentioned above, for a plurality of benefits, such as coverage extension, service reliability enhancement, and potential low latency, sidelink communications have been supported. In the 3GPP Rel-16, there are two types of sidelink resource allocation, called sidelink resource allocation mode 1 and sidelink resource allocation mode 2. With the sidelink resource allocation mode 1, the resources for sidelink transmissions are allocated by the network. With the sidelink resource allocation mode 2, the resources for sidelink transmissions are determined by the transmitting (TX) UE based on its sensing.

In the 3GPP Rel-16, hybrid automatic repeat request (HARQ) feedback was introduced to achieve the high reliability of NR sidelink unicast and groupcast communications. The HARQ feedback for a PSSCH is transmitted on a PSFCH. The period of PSFCH resources in the time domain is configured per resource pool, e.g., 1/2/4 slots within the resource pool, and the minimum gap between PSSCH/PSCCH transmission and PSFCH reception is also configured with 2 or 3 slots. When the period of PSFCH is configured with 2 or 4 slots, the sidelink TX UE may need to receive multiple PSFCHs in one PSFCH occasion, and the multiple PSFCHs in one occasion could be frequency division multiplexed (FDMed) or code division multiplexed (CDMed) .

Besides the PSFCH for HARQ feedback introduced in the 3GPP Rel-16, in the 3GPP release 17 (Rel-17) , the PSFCH for conflict information was introduced for inter-UE coordination. One UE may transmit conflict information in the PSFCH to inform the reserved resource conflict.

In the 3GPP Rel-16, PSFCH resources configuration/determination has been specified as follows:

Moreover, for sidelink resource allocation mode 2, the resource selection procedure has been specified as follows:

Moreover, for sidelink resource allocation mode 2 with omni-directional antennas, e.g., sidelink operation on frequency range 1 (FR1) only, the TX UE determines its candidate resource set based on the sensing, e.g., within its resource selection window. In this case, one resource may be excluded from its candidate resource set if the resource is reserved by another UE and the measured layer 1 reference signal received power (L1-RSRP) is higher than one threshold or one resource may be excluded from its candidate resource set if the TX UE has not monitored the corresponding slots due to half-duplex.

In the 3GPP Rel-18, the sidelink operation on frequency range 2 (FR2) licensed spectrum has been approved in the work item description (WID) of sidelink evolution with the following objective.

This sidelink evolution introduces the sidelink operation on FR2 and mainly focuses on the beam management of sidelink communications. As known, NR beamforming may be categorized as analog beamforming, digital beamforming, and hybrid beamforming. During the beam management procedure, the TX UE and the receiving (RX) UE of a sidelink unicast communication may establish/maintain a beam pair for the sidelink unicast communication.

If the TX UE only supports analog beamforming, the TX UE may only perform transmission/reception with one beam, that is, the TX UE may only perform transmission/reception in one direction. However, due to the configuration of the period of PSFCH with 2 or 4 slots, the TX UE may need to perform multiple PSFCHs reception in a PSFCH occasion. If the reception beams of multiple PSFCHs are the same, there is no issue for multiple PSFCHs receptions, while if the reception beams of multiple PSFCHs are different, e.g., multiple reception beams in multiple directions, the TX UE could not form multiple reception beams to perform PSFCHs reception when the analog beamforming is applied.

Currently, for sidelink resource allocation mode 2 with directional antennas, e.g., sidelink operations on FR2 only, performing the existing sidelink resource selection procedure based on sensing still could not avoid the collision of reception beams of multiple PSFCHs from different directions. In this case, during sidelink resource selection procedure of sidelink resource allocation mode 2 with directional antennas, if the TX UE needs to receive multiple PSFCHs from different RX UEs using different reception beams in different directions in one PSFCH occasion, how to perform the PSFCHs reception in one PSFCH occasion shall be addressed.

In view of the above, as of now, there is no effective way to allow multiple PSFCH receptions in one PSFCH occasion for the TX UE supporting only analog beamforming, when different reception beams need to be applied for different RX UEs. Therefore, there is a need for an improved solution for the PSFCH receptions in such a case.

In view of the above discussions, embodiments of the present disclosure provide a solution for resource selection in sidelink communications. In one aspect of the solution of the present disclosure, a terminal device determines, for a first sidelink transmission, a first transmission resource associated with a first feedback resource, based on information on a second feedback resource associated with a second transmission resource determined for a second sidelink transmission to be transmitted. Moreover, the terminal device transmits the first sidelink transmission on the first transmission resource.

By considering information on the second feedback resource when determining the first transmission resource associated with the first feedback resource for the first sidelink transmission, this solution can reduce negative impacts caused by reception beam collisions, for example, when multiple feedback resources are in the same time domain and their associated reception beams are different. In this way, it is possible to avoid resource waste and improve transmission efficiency.

Principles and implementations of embodiments of the present disclosure will be described in detail below with reference to the figures.

EXAMPLE ENVIRONMENT

Reference is first made to FIG. 1A, which illustrates a schematic diagram of a communication environment 100 in which some embodiments of the present disclosure can be implemented. As shown in FIG. 1A, the communication environment 100, which may be a part of a communication network, comprises terminal devices 110 and 120.

As an example, the terminal devices 110 and 120 may perform a sidelink transmission, which is also referred to as a device-to-device (D2D) communication. Just for the purpose of discussion, in some example embodiments, the terminal device 110 will be taken as an example of a TX device that initiates a sidelink transmission. The terminal device 120 will be taken as an example of an RX device of the sidelink transmission. As another example, the terminal devices 110 and/or 120 may communicate with one or more further terminal devices not shown in FIG. 1A.

The communication environment 100 may further comprise a network device 130. To transmit data and/or control information, the terminal devices 110 and 120 may perform communications with the network device 130, respectively. For transmissions from the network device 130 to the terminal device 110 or 120, the communication link may be referred to as a downlink, whereas for transmissions from the terminal device 110 or 120 to the network device 130, the communication link may be referred to as an uplink.

In some embodiments, the network device 130 may be absent in the communication environment 100. In other words, the terminal devices 110 and 120 as well as possibly other terminal devices (not shown) may be outside of the coverage range of the network device 130. In such cases, only sidelink communications may exist between the terminal devices 110 and 120, and possibly other terminal devices not shown in FIG. 1A.

Although the terminal devices 110 and 120, and the network device 130 are described in the communication environment 100 of FIG. 1A, embodiments of the present disclosure may equally apply to any other suitable communication devices in communication with one another. That is, embodiments of the present disclosure are not limited to the exemplary scenarios of FIG. 1A. In this regard, it is noted that although the terminal devices 110 and 120 are schematically depicted as mobile phones and the network device 130 is schematically depicted as a base station in FIG. 1A, it is understood that these depictions are exemplary in nature without suggesting any limitation. In other embodiments, the terminal devices 110 and 120, and the network device 130 may be any other communication devices, for example, any other wireless communication devices.

It is to be understood that the particular number of various communication devices and the particular number of various communication links as shown in FIG. 1A is for illustration purpose only without suggesting any limitations. The communication environment 100 may include any suitable number of communication devices and any suitable number of communication links for implementing embodiments of the present disclosure. In addition, it should be appreciated that there may be various wireless as well as wireline communications (if needed) among all of the communication devices.

The communications in the communication environment 100 may follow any suitable communication standards or protocols, which are already in existence or to be developed in the future, such as universal mobile telecommunications system (UMTS) , long term evolution (LTE) , LTE-advanced (LTE-A) , the fifth generation (5G) new radio (NR) , wireless fidelity (Wi-Fi) and worldwide interoperability for microwave access (WiMAX) standards, and employs any suitable communication technologies, including, for example, multiple-input multiple-output (MIMO) , orthogonal frequency division multiplexing (OFDM) , time division multiplexing (TDM) , frequency division multiplexing (FDM) , code division multiplexing (CDM) , bluetooth, ZigBee, and machine type communication (MTC) , enhanced mobile broadband (eMBB) , massive machine type communication (mMTC) , ultra-reliable low latency communication (URLLC) , carrier aggregation (CA) , dual connectivity (DC) , and new radio unlicensed (NR-U) technologies.

FIG. 1B illustrates an example communication scenario according to some embodiments of the present disclosure. As shown in FIG. 1B, the UE 1 may perform sidelink transmissions with the UE 2, the UE 3, the UE 4, and the UE 5, and the PSFCH resources associated with the sidelink transmissions with the UE 2, the UE 3, the UE 4, and the UE 5 are in the same PSFCH occasion. Therefore, the UE 1 may need to receive the respective PSFCHs from the UE 2, the UE 3, the UE 4, and the UE 5 in one PSFCH occasion. In this case, if the UE 1 only supports analog beamforming and different reception beams need to be applied for the different UEs, reception beam collisions may occur when performing the PSFCHs reception in one PSFCH occasion.

In this case, to avoid the reception beam collisions, for example, when determining a transmission resource for a sidelink transmission to the UE 2, the UE 1 may take into account information on one or more feedback resources associated with one or more other transmission resources determined for one or more other sidelink transmissions for example, with the UE 3, the UE 4, and/or the UE 5. In this way, potential reception beam collisions can be avoided efficiently.

EXAMPLE METHOD

FIG. 2 illustrates a flowchart of an example method 200 for communication in accordance with some embodiments of the present disclosure. In some embodiments, the method 200 can be implemented at a device in a communication network, such as the terminal device 110 as shown in FIG. 1A. Additionally or alternatively, the method 200 can be implemented at other devices (for example, the terminal device 120) shown in FIG. 1A. In some other embodiments, the method 200 may be implemented at devices not shown in FIG. 1A. Further, it is to be understood that the method 200 may include additional blocks not shown and/or may omit some blocks as shown, and the scope of the present disclosure is not limited in this regard. For the purpose of discussion, the method 200 will be described from the perspective of the terminal device 110 with reference to FIG. 1A.

As shown in FIG. 2, at block 210, the terminal device 110 determines, for a first sidelink transmission, a first transmission resource associated with a first feedback resource, based on information on a second feedback resource associated with a second transmission resource determined for a second sidelink transmission to be transmitted. For example, the sidelink transmission may comprise a transmission of a transport block (TB) , the transmission resource may comprise a resource for the TB, and the feedback resource may comprise a resource for a PSFCH carrying feedback information. As an example, the feedback information may comprise HARQ feedback for the transmission of the TB, or conflict information for informing a reserved resource conflict. Alternatively or additionally, the sidelink transmission may comprise a transmission of a set of TBs, or any other transmissions in other transmission units. Alternatively or additionally, the feedback resource may comprise a resource for any other kinds of channels carrying any other kinds of feedback information.

In some embodiments, if the terminal device 110 works in the sidelink resource allocation mode 2, during the resource selection procedure triggered for the first sidelink transmission, the terminal device 110 may evaluate a candidate transmission resource (for example, a candidate single-slot resource) to determine whether to exclude the candidate transmission resource from a candidate transmission resource set, for example, considering the previous resource selection procedure triggered for the second sidelink transmission before this resource selection procedure. In the previous resource selection procedure, the terminal device 110 may already have selected the second transmission resource for the second sidelink transmission. For example, a resource exclusion procedure may be performed to determine an appropriate transmission resource set for the first sidelink transmission. With the resource exclusion procedure, the terminal device 110 may exclude, based on the information on the second feedback resource, the candidate transmission resource from a first set of candidate transmission resources to obtain a second set of candidate transmission resources. For example, the first set of candidate transmission resources may comprise an initial full set of available resources or a subset of available resources based on the existing resource excluding processing.

In some embodiments, the terminal device 110 may determine whether to perform or skip the resource exclusion procedure. As an example, the terminal device 110 may receive, from the network device 130, an indication about whether to perform or skip the resource exclusion procedure. As another example, the terminal device 110 may determine whether to perform or skip the resource exclusion procedure by itself. For example, if the resource exclusion procedure is skipped, the terminal device 110 may determine or select the first transmission resource from the first set of candidate transmission resources. As another example, if the resource exclusion procedure is performed, the terminal device 110 may determine or select the first transmission resource from the second set of candidate transmission resources.

In some embodiments, the terminal device 110 may exclude the candidate transmission resource from the first set of candidate transmission resources, if a candidate feedback resource associated with the candidate transmission resource is in a same feedback occasion as the second feedback resource, and a reception beam associated with the candidate feedback resource and a reception beam associated with the second feedback resource are different. As an example, in the case where the terminal device 110 intends to receive a candidate PSFCH associated with a candidate transmission resource for a first TB and a second PSFCH associated with a second transmission resource for a second TB, and the second transmission resource is already selected for the second TB within a previous resource selection window, the terminal device 110 may exclude the candidate transmission resource from the candidate transmission resource set, if the candidate PSFCH and the second PSFCH are in the same PSFCH occasion and the reception beams of the candidate PSFCH and the second PSFCH are different.

FIG. 3 illustrates a schematic diagram of resource exclusion during a resource selection window in accordance with some embodiments of the present disclosure. As shown in FIG. 3, the candidate feedback resource associated with the candidate transmission resource for the first sidelink transmission and the second feedback resource associated with the second transmission resource for the second sidelink transmission are in the same feedback occasion (i.e. slot n+5) . If the terminal device 110 performs the first sidelink transmission on the candidate transmission resource and the second sidelink transmission on the second transmission resource and the feedback transmissions for the first and second sidelink transmissions (for example, for HARQ feedback or the conflict information) are enabled, the terminal device 110 may have to receive the feedback transmissions in the slot n+5. If the reception beam associated with the candidate feedback resource and the reception beam associated with the second feedback resource are different, the terminal device 110 may not be able to form one reception beam to receive two feedback transmissions from different directions, so the terminal device 110 may need to perform the resource exclusion procedure to exclude the candidate transmission resource from the candidate transmission resource set to avoid this issue.

Alternatively or additionally, the terminal device 110 may exclude the candidate transmission resource from its candidate transmission resources set following some other kinds of principles and based on some other information or parameters associated with the candidate transmission resource considering the information or parameters associated with the second feedback resource, and the scope of the present disclosure is not limited in this regard.

In some example embodiments, the above resource exclusion procedure may be further optimized, for example, based on at least the priority of the sidelink transmission, and the details will be discussed as follows for different cases.

As described above, the feedback resources may be used to transmit multiple types of feedback information, for example, HARQ feedback or conflict information. For example, the multiple types of feedback information may comprise the first type of feedback information, and the second type of feedback information. For example, the first type of feedback information may comprise the HARQ feedback, and the second type of feedback information may comprise conflict information. Thus, the candidate feedback resource and the second feedback resource may be used to transmit the same type of feedback information or different types of feedback information, including the following four cases:

- Case 1: the candidate feedback resource for the first type of feedback information associated with the candidate transmission resource and the second feedback resource for the first type of feedback information associated with the second transmission resource;

- Case 2: the candidate feedback resource for the second type of feedback information associated with the candidate transmission resource and the second feedback resource for the second type of feedback information associated with the second transmission resource;

- Case 3: the candidate feedback resource for the second type of feedback information associated with the candidate transmission resource and the second feedback resource for the first type of feedback information associated with the second transmission resource;

- Case 4: the candidate feedback resource for the first type of feedback information associated with the candidate transmission resource and the second feedback resource for the second type of feedback information associated with the second transmission resource.

In the following, whether the resource exclusion procedure may be performed will be discussed with reference to the above four cases in detail.

For cases 1 and 2 where the candidate feedback resource and the second feedback resource are used to transmit the same type of feedback information, the determination of whether the resource exclusion procedure may be performed or not may be based on a predefined condition. In this case, the resource exclusion procedure may be performed if the predefined condition is fulfilled.

In some examples, the terminal device 110 may determine whether to perform the resource exclusion procedure based on a priority of the second sidelink transmission and a first priority threshold. The first priority threshold may be configured by the network device 130 or determined by the terminal device 110 itself or determined by pre-configuration. As an example, the resource exclusion procedure may be performed if the priority of the second sidelink transmission is higher than the first priority threshold. In this case, as the second sidelink transmission on the already selected second sidelink resource has higher priority, the terminal device 110 shall protect the reception of the feedback transmission associated with the second sidelink transmission on the second transmission resource.

In some other examples, the terminal device 110 may determine whether to perform the resource exclusion procedure based on a priority of the first sidelink transmission, the priority of the second sidelink transmission and a second priority threshold. The second priority threshold may be configured by the network device 130 or determined by the terminal device 110 itself or determined by pre-configuration. As an example, the resource exclusion procedure may be performed if the priority of the first sidelink transmission and the priority of the second sidelink transmission are higher than the second priority threshold. This approach may be better to avoid the reception beam collision between two feedback transmissions associated with two sidelink transmissions both with higher priorities. In this case, the reception beam collision between the second sidelink transmission with higher priority and the first sidelink transmission with lower priority may be allowed. For example, the second priority threshold is configured to “2” , if the priority of the second sidelink transmission is “0” and the priority of the first sidelink transmission is “1” , the resource exclusion procedure may be performed to avoid the reception beam collision between two feedback transmissions associated with two sidelink transmissions both with higher priorities. As another example, the second priority threshold is configured to “2” , if the priority of the second sidelink transmission is “0” and the priority of the first sidelink transmission is “7” , the resource exclusion procedure may be skipped.

In some further examples, the terminal device 110 may determine whether to perform the resource exclusion procedure based on comparing the priority of the first sidelink transmission and the second sidelink transmission. As an example, the resource exclusion procedure may be performed if the priority of the second sidelink transmission is higher than the priority of the first sidelink transmission. In this case, the resource exclusion procedure may be performed to protect the reception of the feedback transmission associated with the second sidelink transmission with higher priority.

For case 3, the terminal device 110 may determine to perform the resource exclusion procedure if the second feedback resource is used to transmit the first type of feedback information and the candidate feedback resource is used to transmit the second type of feedback information. As an example, the terminal device 110 may determine to perform the resource exclusion procedure, for example, if the terminal device 110 determines that the first type of feedback information is prioritized to the second type of feedback information. In the examples where the first type of feedback information comprises the HARQ feedback information and the second type of feedback information comprises the conflict information, as the HARQ feedback may be considered much more important than the conflict information, in this case, the terminal device 110 may determine to perform the resource exclusion procedure to protect the reception of the HARQ feedback for the second sidelink transmission.

For case 4, the terminal device 110 may determine to skip the resource exclusion procedure if the candidate feedback resource is used to transmit the first type of feedback information, and the second feedback resource is used to transmit a second type of feedback information. As an example, the terminal device 110 may determine to skip the resource exclusion procedure, for example, if the terminal device 110 determines that the first type of feedback information is prioritized to the second type of feedback information. It means that in this case, the terminal device 110 may also select the candidate transmission resource even if it may cause a reception beam collision between the receptions on the associated candidate feedback resource and the associated second feedback resource. And the terminal device 110 may skip the reception of the second type of feedback information. In the examples where the first type of feedback information comprises the HARQ feedback information and the second type of feedback information comprises the conflict information, as the HARQ feedback may be considered much more important than the conflict information, in this case, the terminal device 110 may determine to skip the resource exclusion procedure.

Then, as shown in FIG. 2, at block 220, the terminal device 110 may transmit the first sidelink transmission on the first transmission resource.

In some embodiments, if the above resource exclusion procedure is not performed or if the legacy sidelink resource allocation mode 1 or sidelink resource allocation mode 2 are applied, the terminal device 110 may have to receive the feedback transmissions (for example, PSFCHs) on a plurality of feedback resources (including the first feedback resource and the second feedback resource) in a feedback occasion, though the reception beams needed for these feedback transmissions are different. In this case, the terminal device 110 may need to determine a reception beam for these feedback transmissions for the feedback occasion. The reception beam for the feedback occasion may be determined in a variety of means.

In some examples, the terminal device 110 may determine the reception beam for the feedback occasion based on the priorities of the sidelink transmissions. In this case, the terminal device 110 may determine the reception beam for the feedback occasion as a reception beam associated with a feedback resource for a sidelink transmission with a highest priority among the plurality of feedback resources.

As an example, the terminal device 110 may determine the reception beam of a PSFCH for the feedback occasion based on the priorities of the associated PSSCHs/PSCCHs. When the terminal device 110 is expected to receive multiple PSFCHs with different reception beams, the terminal device 110 may determine to form the reception beam to receive the PSFCH associated with the PSSCH with the highest priority among the multiple PSSCHs.

In some other examples, the terminal device 110 may determine the reception beam for the feedback occasion based on the priorities of the sidelink transmissions associated with a certain type of feedback information. For example, the highest priority may only be determined from the sidelink transmissions associated with the first type of feedback information or the sidelink transmissions associated with the second type of feedback information. In the examples where the first type of feedback information comprises the HARQ feedback information and the second type of feedback information comprises the conflict information, the terminal device 110 may determine the reception beam for the feedback occasion as a reception beam associated with a feedback resource for the first type of feedback information for a sidelink transmission with a highest priority among the plurality of feedback resources.

As an example, if multiple PSFCHs comprise a first plurality of PSFCHs for the HARQ feedback and a second plurality of PSFCHs for the conflict information, the terminal device 110 may determine to form the reception beam to receive the PSFCH associated with the PSSCH with the highest priority among the multiple PSSCHs associated with the first plurality of PSFCHs. In this case, the PSFCH for the HARQ feedback may be prioritized to the PSFCH for the conflict information.

In some further examples, the terminal device 110 may determine the reception beam for the feedback occasion based on a total number of feedback resources (or feedback transmissions) within each of the reception beams. In this case, the terminal device 110 may determine the reception beam for the feedback occasion as a reception beam associated with the largest number of feedback resources.

As an example, the terminal device 110 may determine the reception beam of PSFCH for the feedback occasion based on the total number of PSFCHs within each reception beam. Each reception beam may be associated with one or more PSFCHs, the terminal device 110 may determine to form the reception beam based on the total number of PSFCH (s) within each reception beam. For instance, if one reception beam is associated with 3 PSFCHs and another reception beam is associated with 1 PSFCH, the terminal device 110 may determine to form the reception beam to receive 3 PSFCHs.

With the determined reception beam, the terminal device 110 may miss one or more feedback transmissions. However, at a transmission side (for example, including the terminal device 120) for a feedback transmission, the terminal device 120 may still perform feedback transmission although the terminal device 110 is unable to receive the feedback transmission on the feedback resource. In this case, in some embodiments, to avoid the feedback transmission at the terminal device 120, the terminal device 110 may transmit, to the second terminal device 120, an indication to disable the feedback transmission on the feedback resource. For example, the indication may be transmitted in sidelink control information (SCI) .

In the example where the feedback transmission comprises the HARQ feedback, the terminal device 110 may disable the HARQ feedback in the SCI, for example, by setting the value of “HARQ feedback enabled/disabled indicator” in the 2nd-stage SCI to “0”to avoid the transmission of the PSFCH from the terminal device 120. In the example where the feedback transmission comprises the collision information, the terminal device 110 may disable the collision information in the SCI, for example, by setting “conflict information receiver flag” in the 1st stage SCI to “0” to avoid the transmission of the PSFCH from the terminal device 120.

The example method 200 may generally apply to the sidelink resource allocation mode 2 where the resources for sidelink transmissions are determined by the terminal device 110 based on its sensing. In addition, for sidelink resource allocation mode 1 where the resources for sidelink transmissions are allocated by the network device 130, if the network device 130 allocates the sidelink resources according to the existing allocation approach as specified in the specification, the collision of reception beams as described above may still happen.

In this case, to address this issue, the terminal device 110 may report assisting information to the network device 130 to assist the scheduling of the network device 130. The assisting information may be transmitted, for example, via a radio resource control (RRC) signaling or a media access control control element (MAC-CE) . For example, the reporting information may comprise the capability or type of beamforming on sidelink operations. As an example, the terminal device 110 may report the type of beamforming to the network device 130, e.g., only support analog beamforming on the sidelink operations. Alternatively or additionally, the reporting information may comprise a reception beam associated with a feedback resource for a sidelink unicast communication. As an example, the terminal device 110 may report its reception beam information to the network device 130. If beam correspondence is supported by the terminal device 110, the reporting reception beam may be the transmission beam of the terminal device 110 for that sidelink unicast communication. With the reported information, the network device 130 may avoid the collision (s) of reception beams associated with feedback resources in one feedback occasion with its implementation.

EXAMPLE DEVICE

FIG. 4 illustrates a simplified block diagram of a device 400 (also termed as an apparatus 1100) that is suitable for implementing embodiments of the present disclosure. The device 400 can be considered as a further example implementation of the terminal devices 110 and 120, and the network device 130 as shown in FIG. 1A. Accordingly, the device 400 can be implemented at or as at least a part of the terminal devices 110 and 120, and the network device 130.

As shown, the device 400 includes a processor 410, a memory 420 coupled to the processor 410, a suitable transmitter (TX) and receiver (RX) 440 coupled to the processor 410, and a communication interface coupled to the TX/RX 440. The memory 410 stores at least a part of a program 430. The TX/RX 440 is for bidirectional communications. The TX/RX 440 has at least one antenna to facilitate communication, though in practice an Access Node mentioned in this disclosure may have several ones. The communication interface may represent any interface that is necessary for communication with other network elements, such as X2 interface for bidirectional communications between eNBs, S1 interface for communication between a Mobility Management Entity (MME) /Serving Gateway (S-GW) and the eNB, Un interface for communication between the eNB and a relay node (RN) , Uu interface for communication between the eNB and a terminal device, or PC5 interface for communication between two terminal devices.

The program 430 is assumed to include program instructions that, when executed by the associated processor 410, enable the device 400 to operate in accordance with the embodiments of the present disclosure, as discussed herein with reference to FIGS. 1A to 3. The embodiments herein may be implemented by computer software executable by the processor 410 of the device 400, or by hardware, or by a combination of software and hardware. The processor 410 may be configured to implement various embodiments of the present disclosure. Furthermore, a combination of the processor 410 and memory 420 may form processing means 450 adapted to implement various embodiments of the present disclosure.

The memory 420 may be of any type suitable to the local technical network and may be implemented using any suitable data storage technology, such as a non-transitory computer readable storage medium, semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory, as non-limiting examples. While only one memory 420 is shown in the device 400, there may be several physically distinct memory modules in the device 400. The processor 410 may be of any type suitable to the local technical network, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 400 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

In some embodiments, an apparatus capable of performing the method 200 (for example, the terminal device 110) may comprise means for performing the respective steps of the method 200. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. In some embodiments, the means comprises at least one processor and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the method 200.

In some embodiments, the apparatus comprises: means for determining, for a first sidelink transmission, a first transmission resource associated with a first feedback resource, based on information on a second feedback resource associated with a second transmission resource determined for a second sidelink transmission to be transmitted; and means for transmitting the first sidelink transmission on the first transmission resource.

Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representation, it will be appreciated that the blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out the process or method as described above. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the processor or controller, cause the functions/operations specified in the flowcharts and/or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

The above program code may be embodied on a machine readable medium, which may be any tangible medium that may contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. The machine readable medium may be a machine readable signal medium or a machine readable storage medium. A machine readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the machine readable storage medium would include 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) , an optical fiber, a portable compact disc read-only memory (CD-ROM) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

Further, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.

Although the present disclosure has been described in language specific to structural features and/or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

A terminal device comprising:

a processor; and

a transceiver coupled to the processor,

wherein the processor is configured to:

determine, for a first sidelink transmission, a first transmission resource associated with a first feedback resource, based on information on a second feedback resource associated with a second transmission resource determined for a second sidelink transmission to be transmitted; and

transmit, via the transceiver, the first sidelink transmission on the first transmission resource.
The terminal device of claim 1, wherein determining the first transmission resource comprises:

determining whether to perform or skip a resource exclusion procedure in which a candidate transmission resource is excluded, based on the information on the second feedback resource, from a first set of candidate transmission resources to obtain a second set of candidate transmission resources;

in the case that the resource exclusion procedure is skipped, selecting the first transmission resource from the first set of candidate transmission resources; and

in the case that the resource exclusion procedure is performed, selecting the first transmission resource from the second set of candidate transmission resources.
The terminal device of claim 2, wherein the resource exclusion procedure comprises:

excluding the candidate transmission resource from the first set of candidate transmission resources in the case that:

a candidate feedback resource associated with the candidate transmission resource is in a same feedback occasion as the second feedback resource; and

a reception beam associated with the candidate feedback resource and a reception beam associated with the second feedback resource are different.
The terminal device of claim 2, wherein the resource exclusion procedure is performed in the case that a predefined condition is fulfilled.
The terminal device of claim 4, wherein the candidate feedback resource and the second feedback resource are used to transmit a same type of feedback information, and the predefined condition comprises one of:

a priority of the second sidelink transmission is higher than a first priority threshold; or

a priority of the first sidelink transmission and the priority of the second sidelink transmission are higher than a second priority threshold; or

the priority of the second sidelink transmission is higher than the priority of the first sidelink transmission.
The terminal device of claim 4, wherein the predefined condition comprises:

the second feedback resource is used to transmit a first type of feedback information; and

the candidate feedback resource is used to transmit a second type of feedback information.
The terminal device of claim 2, wherein the resource exclusion procedure is skipped in the case that:

the candidate feedback resource is used to transmit a first type of feedback information; and

the second feedback resource is used to transmit a second type of feedback information.
The terminal device of claim 6 or 7, wherein:

the first type of feedback information comprises hybrid automatic repeat request (HARQ) feedback; or

the second type of feedback information comprises conflict information for informing a reserved resource conflict.
The terminal device of claim 1, wherein a plurality of feedback resources including the first feedback resource and the second feedback resource are in a feedback occasion, and the processor is further configured to:

determine a reception beam for the feedback occasion as one of:

a reception beam associated with a feedback resource for a sidelink transmission with a highest priority among the plurality of feedback resources; or

a reception beam associated with a largest number of feedback resources.
The terminal device of claim 9, wherein the terminal device is a first terminal device, and the processor is further configured to:

transmit, to a second terminal device via the transceiver, an indication to disable a feedback transmission on a feedback resource, in the case that the first terminal device is unable to receive the feedback transmission on the feedback resource.
The terminal device of claim 10, wherein the indication is transmitted in sidelink control information (SCI) .
A method performed by a terminal device, comprising:

determining, for a first sidelink transmission, a first transmission resource associated with a first feedback resource, based on information on a second feedback resource associated with a second transmission resource determined for a second sidelink transmission to be transmitted; and

transmitting the first sidelink transmission on the first transmission resource.
A non-transitory computer readable medium having program instructions stored thereon that, when executed by an apparatus, cause the apparatus at least to:

determine, for a first sidelink transmission, a first transmission resource associated with a first feedback resource, based on information on a second feedback resource associated with a second transmission resource determined for a second sidelink transmission to be transmitted; and

transmit the first sidelink transmission on the first transmission resource.