EP3895354A1

EP3895354A1 - Device and method for supporting a feedback mechanism

Info

Publication number: EP3895354A1
Application number: EP18827080.5A
Authority: EP
Inventors: Richard Stirling-Gallacher; Jian Luo; Chan Zhou; Serkan AYAZ; Zhongfeng Li
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2018-12-20
Filing date: 2018-12-20
Publication date: 2021-10-20
Also published as: WO2020125990A1; CN113228542A; CN113228542B

Abstract

The present invention provides a network device for supporting a User Equipment (UE) feedback mechanism to a unicast or a groupcast or a multicast or a broadcast transmission. The network device is configured to determine one or more of feedback channel resources for one UE or a subgroup or a group of UEs, wherein each determined feedback channel resource is a UE specific feedback channel resource or a shared feedback channel resource for one UE or a group or a subgroup of the UEs; and send, to a UE or a subgroup or a group of the UEs, a UE specific or subgroup specific or group specific signalling comprising one or more parameters being indicative of at least one of the determined feedback channel resources. This invention also provides a wireless communication device (UE). The wireless communication device is configured to receive, from a network device, a UE specific signal or a subgroup specific signal comprising one or more resource parameters being indicative of at least one determined feedback channel resource; and send one or more feedback messages to the network device and/or another node using the at least one determined feedback channel resource, wherein the at least one determined feedback channel resource is a UE specific feedback channel resource or a shared feedback channel resource for a subgroup of the UEs.

Description

DEVICE AND METHOD FOR SUPPORTING A FEEDBACK MECHANISM

TECHNICAL FIELD

The present invention relates generally to the field of wireless communication, particularly of supporting a feedback mechanism for a transmission such as, a unicast, a groupcast, a broadcast, a multicast, etc. To this end, the invention proposes a network device that is configured to determine feedback channel resources and, send, for example, to a UE a signalling including a parameter being indicative of the determined feedback channel resources. The invention also proposes a wireless communication device that receives the signalling and, for example, sends a feedback message in the determined feedback channel resource.

BACKGROUND

Generally, there is a need for a capable Vehicle to Everything (V2X) (e.g., vehicle to vehicle, vehicle to infrastructure, vehicle to network, vehicle to pedestrian, etc.) or a cellular intelligent transportation system (C-ITS) communication systems to support the increasing need of, for example, the vehicle safety, the traffic management, the different levels of assistance for automated driving, etc.

In order to provide such a capable service, the following technical problems are required to be solved:

• The reliability and the efficiency of the Sidelink (SL) groupcast and/or unicast transmission needs to be improved, for example, by providing a SL feedback mechanism. In other words, a mechanism for providing feedback for the SL groupcast and/or unicast is required.

• Optimization of the conventional feedback mechanisms is also required, for example, to further improve the performance of the SL groupcast and/or unicast including, the overhead of the feedback, the latency for the feedback, the reliability of the feedback. Conventional devices and methods are known that provide multicast transmissions, for example, the Long Term Evolution (LTE) V2X (described in the TS 36.321 document). However, a feedback mechanism is not supported for the provided multicast transmission, and the conventional device and method in the LTE V2X provides up to two transmissions including a blind retransmission for enhancing the coverage or the reliability. The conventional devices and methods have the following disadvantages:

• No feedback mechanism is supported.

• Typically a conservative modulation and coding scheme (MCS) is used.

• It has a low efficiency, for example, it provides up to one blind retransmission.

Moreover, conventional devices and methods are also known that provide a broadcast or a multicast feedback mechanism, e.g., with a shared channel carrying only negative acknowledgement (NACK) information. However, the shared channel Hybrid Automatic Repeat Request (HARQ) NACK feedback may cause a high received NACK power, which has the following disadvantages:

• It is bad for Automatic Gain Control (AGC) adjustment of the receiver, due to having a large power imbalance.

• It is bad for interference control to other receiving nodes or the receiving neighbor nodes, furthermore, the interference may be fluctuated due to uncertain received NACK feedback number.

• It is bad for the differentiation of decoding result for each received User Equipment (UE).

SUMMARY

In view of the above-mentioned problems and disadvantages, the present invention aims to improve the conventional devices and methods for supporting a User Equipment (UE) feedback mechanism. An objective is in particular to provide a network device, wireless communication device, and corresponding methods for supporting a UE feedback mechanism to a unicast, groupcast, multicast, or broadcast transmission. The objective of the present invention is achieved by the solution provided in the enclosed independent claims. Advantageous implementations of the present invention are further defined in the dependent claims.

A first aspect of the invention provides a network device for supporting a User Equipment, UE, feedback mechanism to a unicast or a groupcast or a multicast or a broadcast transmission, the network device being configured to determine one or more of feedback channel resources for one UE or a subgroup or a group of UEs, wherein each determined feedback channel resource is a UE specific feedback channel resource or a shared feedback channel resource for one UE or a group or a subgroup of the UEs; and send, to a UE or a subgroup or a group of the UEs, a UE specific or subgroup specific or group specific signalling comprising one or more parameters being indicative of at least one of the determined feedback channel resources.

The network device may be a device such as a transmitter device, a relayed device, a scheduling device, a UE, a next generation NodeB (gNB), a Road Side Unit (RSU), a Relay Node (RN), etc. The network device may also be a device that supports the out of coverage UEs, etc.

For example, the feedback resource may be a feedback channel resource. Moreover, in some embodiments, the UE specific feedback resource may be supported for both unicast and the groupcast transmission. In some embodiments, the UE shared feedback channel resource (also hereinafter referred to common feedback channel resource) may be supported for groupcast transmission. Moreover, in some embodiments, both the UE specific feedback channel resource for the unicast or the groupcast transmission and the UE common feedback resource for the groupcast transmission may support a direct feedback to a destination device or a relayed feedback (e.g., via a relayed device) to the destination device.

In an implementation form of the first aspect, the network device is further configured to determine a correspondence between a group Identification (ID) and/or a subgroup ID, with one or more of: • A UE index.

• A UE identification.

• A feedback index. In a further implementation form of the first aspect, the UE specific signalling or the subgroup specific signalling or the group specific signalling is sent based on the determined correspondence.

This is beneficial, since the correspondence may be determined. Moreover, based on the determined correspondence a signal may be sent, which may be the UE specific signalling, or the subgroup specific signalling, or the group specific signalling.

In a further implementation form of the first aspect, each determined feedback channel resource is configured to support one or more of:

• A feedback to a destination device.

• A relayed feedback via a relayed device to a destination device.

This is beneficial, since a feedback message may be sent.

In a further implementation form of the first aspect, the UE specific signalling and/or group specific signalling and/or subgroup specific signalling comprises one or more of:

• A higher layer signalling indicating a group specific or subgroup specific feedback channel parameters; and/or

• A lower layer signalling indicating a group specific or subgroup specific feedback channel resource indication value; and/or

• A higher layer signalling indicating an association between UE ID or UE index and group ID or subgroup ID; and/or

• A higher layer signalling indicating an association between UE ID or UE index and feedback index carried in a group or subgroup specific lower layer signalling.

This is beneficial, since it may be determined, which UE correctly decoded and/or which UE does not correctly decode, etc. In a further implementation form of the first aspect, the network device is further configured to multiplex two or more feedback channel resources based on a time sequencing and/or a frequency sequencing and/or a code sequencing. This is beneficial, since an efficient feedback channel resource multiplexing among different UEs may be supported.

In a further implementation form of the first aspect, the network device is further configured to receive one or more feedback messages from one or more of the UEs, wherein the feedback message of each UE is received in the determined UE specific feedback channel resource or the determined shared feedback channel resource.

In a further implementation form of the first aspect, the received feedback message comprises a negative acknowledgement, NACK and/or an acknowledgement, ACK.

For the aggregated embodiments, the gNB may receive, for example, the relayed ACK or NACK after the processing of the relaying UE, only NACK when there is at least one NACK, only ACK when all the received is ACK. For the concatenation embodiments, the gNB may receive, for example, both ACK and NACK which may be supported.

In a further implementation form of the first aspect, each feedback channel resource is determined by one or more of:

• A starting position of a Physical Downlink Control Channel, PDCCH.

• A starting position of a Physical Sidelink Control Channel, PSCCH.

• A starting position of a control channel.

• A resource pool configuration of data channel.

• A resource pool configuration of feedback channel and/or control channel.

• A predefined or configured association between data channel and/or control channel and feedback channel resource pool.

• A group specific Downlink Control Information, DCI, indicated value.

• A group specific Sidelink Control Information, SCI, indicated value. • A group specific Radio Resource Control, RRC, and/or MAC Control Element, MAC CE.

• An indicated feedback resource parameters.

• A group specific high layer signalling indicated feedback resource parameters.

• An UE index.

• An offset k or a group specific higher layer signaling indicated value.

• A feedback index.

• A group ID.

• A subgroup ID.

• A sequence type.

• A cyclic shift value.

• An OCC index.

• A scrambling ID.

• A transmission type of unicast or groupcast or both.

A second aspect of the invention provides a method for supporting a User Equipment, UE, feedback mechanism to a unicast or a groupcast or a multicast or a broadcast transmission, the method comprising determining one or more of feedback channel resources for one UE or a subgroup or a group of UEs, wherein each determined feedback channel resource is a UE specific feedback channel resource or a shared feedback channel resource for one UE or a group or a subgroup of the UEs; and sending, to a UE or a subgroup or a group of the UEs, a UE specific or subgroup specific or group specific signalling comprising one or more parameters being indicative of at least one of the determined feedback channel resources.

In an implementation form of the second aspect, the method further comprising determining a correspondence between a group Identification (ID) and/or a subgroup ID, with one or more of:

• A UE index.

• A UE identification.

• A feedback index. In a further implementation form of the second aspect, the UE specific signalling or the subgroup specific signalling or the group specific signalling is sent based on the determined correspondence.

In a further implementation form of the second aspect, each determined feedback channel resource is configured to support one or more of:

• A feedback to a destination device.

• A relayed feedback via a relayed device to a destination device.

In a further implementation form of the second aspect, the UE specific signalling and/or group specific signalling and/or subgroup specific signalling comprises one or more of:

In a further implementation form of the second aspect, the method further comprising multiplexing two or more feedback channel resources based on a time sequencing and/or a frequency sequencing and/or a code sequencing.

In a further implementation form of the second aspect, the method further comprising receiving one or more feedback messages from one or more of the UEs, wherein the feedback message of each UE is received in the determined UE specific feedback channel resource or the determined shared feedback channel resource.

In a further implementation form of the second aspect, the received feedback message comprises a negative acknowledgement, NACK and/or an acknowledgement, ACK. In a further implementation form of the second aspect, each feedback channel resource is determined by one or more of:

• A starting position of a Physical Downlink Control Channel, PDCCH.

• A starting position of a Physical Sidelink Control Channel, PSCCH.

• A starting position of a control channel

• A resource pool configuration of data channel.

• A resource pool configuration of feedback channel and/or control channel.

• A group specific Downlink Control Information, DCI, indicated value.

• A group specific Sidelink Control Information, SCI, indicated value.

• A group specific Radio Resource Control, RRC, and/or MAC Control Element, MAC CE.

• An indicated feedback resource parameters.

• An UE index.

• An offset k or a group specific higher layer signaling indicated value.

• A feedback index.

• A group ID.

• A subgroup ID.

• A sequence type.

• A cyclic shift value.

• An OCC index.

• A scrambling ID.

• A transmission type of unicast or groupcast or both.

A third aspect of the invention provides a wireless communication device, UE, configured to receive, from a network device, a UE specific signalling or a subgroup specific signalling comprising one or more parameters being indicative of at least one determined feedback channel resource; and send one or more feedback messages to the network device and/or another node using the at least one determined feedback channel resource, wherein the at least one determined feedback channel resource is a UE specific feedback channel resource or a shared feedback channel resource for a subgroup or a group of the UEs.

For example, the network device (e.g., the gNB, the UE, the RSU, the RN, etc.) may determine the feedback channel resources. Moreover, the wireless communication device (e.g., the UE) may send feedback messages to the network device and/or another node using the determined feedback channel resource. This is beneficial, since the feedback mechanism may be supported.

In an implementation form of the third aspect, the UE specific signalling or the subgroup specific signalling or the group specific signalling is indicative of a correspondence between a group Identification, ID, with one or more of:

• A UE index.

• A UE identification.

• A feedback index.

In a further implementation form of the third aspect, the sent feedback message comprises a negative acknowledgement, NACK and/or an acknowledgement, ACK.

In a further implementation form of the third aspect, each feedback channel resource is determined by one or more of:

• A starting position of a Physical Downlink Control Channel, PDCCH.

• A starting position of a Physical Sidelink Control Channel, PSCCH.

• A starting position of a control channel

• A resource pool configuration of data channel.

• A resource pool configuration of feedback channel and/or control channel.

• A group Downlink Control Information, DCI, indicated value.

• A group Sidelink Control Information, SCI, indicated value.

• A group specific Radio Resource Control, RRC, and/or MAC Control Element, MAC CE. • An indicated feedback resource parameters.

• An UE index.

• An offset k or a group specific higher layer signaling indicated value.

• A feedback index.

• A group ID.

• A subgroup ID.

• A sequence type.

• A cyclic shift value.

• An OCC index.

• A scrambling ID.

• A transmission type of unicast or groupcast or both.

In a further implementation form of the third aspect, the wireless communication device is further configured to send, when being a relaying UE, an aggregated Hybrid Automatic Repeat Request, HARQ, feedback message to another node, wherein the aggregated HARQ feedback message comprises a NACK, if at least one feedback message is NACK or ACK when all the received feedback are ACK.

For example, the unicast may also use the relaying UE, e.g., several devices communicate with unicast (e.g., C B A) which sometimes this may not be defined as the group. Moreover, it may be supported for the group, subgroup, one UE, etc., without limiting the invention.

In a further implementation form of the third aspect, the wireless communication device is further configured to send, when being a relaying UE, a concatenated HARQ feedback message to another node, wherein the concatenated HARQ feedback message comprises one or more feedback messages received from a UE or the group of UEs or the subgroup ofUEs.

For example, the unicast may also use the relaying UE, e.g., several devices communicate with unicast (e.g., C B A) which sometimes this may not be defined as the group. Moreover, it may be supported for the group, subgroup, one UE, etc., without limiting the invention. In some embodiments, the relaying UE may be the leading UE or the configured UE, without limiting the invention.

A fourth aspect of the invention provides a method of a wireless communication device, UE, the method comprising receiving, from a network device, a UE specific signalling or a group specific signalling or a subgroup specific signalling comprising one or more parameters being indicative of at least one determined feedback channel resource; and sending one or more feedback messages to the network device and/or another node using the at least one determined feedback channel resource, wherein the at least one determined feedback channel resource is a UE specific feedback channel resource or a shared feedback channel resource for a UE or a group of the UEs or a subgroup of the UEs.

In an implementation form of the fourth aspect, the UE specific signalling or the group specific signaling or the subgroup specific signalling is indicative of a correspondence between a group Identification, ID, with one or more of:

• A UE index.

• A UE identification.

• A feedback index.

In a further implementation form of the fourth aspect, the send feedback message comprises a negative acknowledgement, NACK and/or an acknowledgement, ACK.

In a further implementation form of the fourth aspect, each feedback channel resource is determined by one or more of:

• A starting position of a Physical Downlink Control Channel, PDCCH.

• A starting position of a Physical Sidelink Control Channel, PSCCH.

• A starting position of a control channel.

• A resource pool configuration of data channel.

• A resource pool configuration of feedback channel and/or control channel.

• A group Downlink Control Information, DCI, indicated value. • A group Sidelink Control Information, SCI, indicated value.

• An indicated feedback resource parameters.

• An UE index.

• An offset k or a group specific higher layer signaling indicated value.

• A feedback index.

• A group ID.

• A subgroup ID.

• A sequence type.

• A cyclic shift value.

• An OCC index.

• A scrambling ID.

• A transmission type of unicast or groupcast or both.

In a further implementation form of the fourth aspect, the method further comprising sending, when being a relaying UE, an aggregated Hybrid Automatic Repeat Request, HARQ, feedback message to another node, wherein the aggregated HARQ feedback message comprises a NACK, if at least one feedback message is NACK or ACK when all the received feedback are ACK.

In a further implementation form of the fourth aspect, the method further comprising sending, when being a relaying UE, a concatenated HARQ feedback message to another node, wherein the concatenated HARQ feedback message comprises one or more feedback messages received from a UE or the subgroup of UEs.

The main advantages of embodiments of the invention can be summarized as follows:

• Balanced received power, due to the UE specific feedback channel resource configuration.

• Balanced interference to other UEs or other nodes, due to the UE specific feedback channel resource configuration. • Efficient feedback channel resource multiplexing among different UEs.

^■ Supporting orthogonal multiplexing with sequence and/or code and/or time and/or frequency.

^■ Supporting NACK only feedback in the UE specific feedback channel resource.

^■ Supporting aggregated or concatenated feedback

• Determining (e.g., exactly) which UE did not correctly decode.

^■ It can be determined, with the UE specific retransmission and/or with the UE specific beamforming.

It has to be noted that all devices, elements, units and means described in the present application could be implemented in the software or hardware elements or any kind of combination thereof. All steps which are performed by the various entities described in the present application as well as the functionalities described to be performed by the various entities are intended to mean that the respective entity is adapted to or configured to perform the respective steps and functionalities. Even if, in the following description of specific embodiments, a specific functionality or step to be performed by external entities is not reflected in the description of a specific detailed element of that entity which performs that specific step or functionality, it should be clear for a skilled person that these methods and functionalities can be implemented in respective software or hardware elements, or any kind of combination thereof.

BRIEF DESCRIPTION OF DRAWINGS The above described aspects and implementation forms of the present invention will be explained in the following description of specific embodiments in relation to the enclosed drawings, in which

FIG. 1 schematically illustrates a network device for supporting a UE feedback mechanism, according to various embodiments of the invention.

FIG. 2 schematically illustrates a procedure for supporting a feedback mechanism for a unicast transmission and/or a groupcast transmission, according to various embodiments of the invention. FIG. 3 schematically illustrates a procedure for determining a correspondence by the network device and supporting a feedback mechanism, according to various embodiments of the invention.

FIG. 4 schematically illustrates a procedure for obtaining the correspondence by the wireless communication device and supporting a feedback mechanism, according to various embodiments of the invention. FIG. 5 schematically illustrates a system for supporting the feedback mechanism for the groupcast transmission, according to various embodiments of the invention.

FIG. 6 schematically illustrates a procedure for supporting the feedback mechanism by the network device, according to various embodiments of the invention.

FIG. 7 schematically illustrates a procedure for supporting the feedback mechanism from the side of the wireless communication device, according to various embodiments of the invention. FIG. 8 schematically illustrates a system for supporting a subgroup based shared feedback channel resource, according to various embodiments of the invention.

FIG. 9 schematically illustrates a method for supporting a UE feedback mechanism to a unicast or a groupcast or a multicast or a broadcast transmission, according to various embodiments of the invention.

FIG. 10 schematically illustrates of a method of a wireless communication device, according to various embodiments of the invention. DETAILED DESCRIPTION OF EMBODIMENTS

FIG. 1 schematically illustrate a network device 100 for supporting a UE feedback mechanism, according to various embodiments of the invention. The feedback mechanism may be supported to a unicast or a groupcast or a multicast or a broadcast transmission.

The network device 100 is configured to determine one or more of feedback channel resources 101 for one UE 110 or a subgroup or a group of UEs 110, wherein each determined feedback channel resource 101 is a UE specific feedback channel resource or a shared feedback channel resource for one UE 110 or a group or a subgroup of the UEs 110.

The network device 100 is further configured to send, to a UE 110 or a subgroup or a group of the UEs 110, a UE specific or subgroup specific or group specific signalling 102 comprising one or more parameters 103 being indicative of at least one of the determined feedback channel resources 101.

For example, in some embodiments, the UE specific feedback channel resource for the groupcast transmission in the SL or the Uu link may be determined. The group specific high layer signalling may be used which may include one or more than one of HARQ feedback resource configuration parameters. Moreover, the correspondence between the UE index and the group ID may be configured and the UE index may be associated with the feedback resource. The feedback resource may be determined and the feedback mechanism may be supported. Moreover, the UE may be configured to receive and/or transmit a message targeting for one and/or more than one UEs. As a response, the UE may determine the feedback resource according to the group specific parameter and/or the UE specific parameter.

FIG. 2 schematically illustrates a procedure 200 for supporting a feedback mechanism for a unicast transmission and/or a groupcast transmission, according to various embodiments of the invention.

The procedure 200 may be (e.g., fully or partially) performed by the network device 100 and/or the wireless communication device 110, as described above.

At 201, the network device initiates supporting the feedback mechanism. The feedback mechanism may be supported for the unicast transition and/or the groupcast transition. For example, in some embodiments, the network device may support the UE specific feedback channel resource for both the unicast and the groupcast transmission. Moreover, in some embodiments, the network device may support the UE common or shared feedback channel resource for the groupcast transmission.

At 202, the network device determines the feedback resource.

At 203, the feedback message may be sent using the determined feedback channel resource. For example, both of the UE specific feedback channel resource for the unicast or the groupcast and the UE shared feedback channel resources for the groupcast may support a direct feedback to a destination device and/or a relayed feedback (e.g., via a relayed device) to a destination device.

In some embodiments, the network device may determine, for example, the UE specific (e.g., the device specific) HARQ feedback resource based on the group and/or the device specific signalling for the transmitter device and/or the relayed device and/or the scheduling device. The transmitter device, the relayed device, the scheduling device may be, for example, the UE, the gNB, the road side unit (RSU), the relay node (RN), etc.

In some embodiments, the UE specific signalling for the groupcast feedback Physical Uplink Control Channel (FB PUCCH) resource or the groupcast Physical Sidelink Feedback Channel (PSFCH) may be sent. For example, the UE specific signalling may indicate one or more than one of the groupcast HARQ feedback resource configuration parameters, the PUCCH resource parameters, the sidelink feedback resource parameters. The parameters may include, for example, the sequence type, the base sequence, the pseudo random (PN) sequence, the cyclic shift, the orthogonal cover code, the scrambling ID, the time, the frequency, the UE ID, the UE index, the group ID, etc. For example, the UE specific signalling may just indicate or reuse the unicast symbol number configuration for the groupcast. In addition, the group identification e.g., the group Radio Network Temporary Identifier (RNTI) may be included in the UE specific signalling so that the UE may use the UE specific configuration for the groupcast transmission or it may identify the groupcast transmission. In some embodiments, the correspondence between the UE index and/or the UE ID and/or the feedback index correspondence with the group identification and/or the subgroup identification may be determined.

For example, in order to support the UE specific feedback resource configuration, the UE index and/or the UE ID and/or the feedback index correspondence with the group or the subgroup identification may be defined, configured, etc.

In some embodiments, the UE specific signalling may indicate the correspondence of the UE index and/or the UE ID and/or the feedback index with the group or subgroup. In some embodiments, the Group specific signalling may indicate the correspondence between the UE index and/or the UE ID and/or the feedback index and the group ID for the UE within the group or the subgroup.

In the following, exemplary procedures from the transmitter side and the receiver side for determining the correspondence between the UE ID and/or the UE index and/or the feedback index with the group or the subgroup ID are illustrated.

In some embodiments, the UE specific signalling may be used, and furthermore, the UE index and/or the feedback index and the group ID may be configured. In some embodiments, the group specific signalling may be used, and furthermore, the UE ID and/or the UE index and/or the feedback index and the group ID may be configured. The UE specific signalling may have the benefit of being more flexible than the group specific signalling. The group specific signalling may have less overhead than the UE specific signalling due to the group ID sharing among the UEs. As an alternative method, the feedback index may be used to indicate the bit position of the corresponding UE in the groupcast feedback resource indication. For example, it may be supported by defining a group specific control information.

FIG. 3 schematically illustrates a procedure 300 for determining a correspondence by the network device and supporting a feedback mechanism, according to various embodiments of the invention. At 301, the device A (e.g., the network device 100) initiates determining (e.g., configuring) the correspondence between the UE ID or the UE index or the feedback index and the UE group identification, e.g., the group RNTI.

At 302, in some embodiments, the device A (e.g., the network device 100) itself may configure the correspondence between the UE ID or the UE index or the feedback index of, for example, the UE B (i.e., another UE) and the group ID. In some embodiments, the device A may configure the correspondence between the UE ID or the UE index or the feedback index of the UE B and the group ID through the device C.

At 303, in some embodiments, the device A (e.g., the network device 100) may configure (e.g., determine) one correspondence between the UE ID or the UE index or the feedback index and the group ID or more than one correspondence between the UE ID or the UE index or the feedback index and the group ID. In some embodiments, the device C (another device than the device A) may configure (e.g., determine) one correspondence between the UE ID or the UE index or the feedback index and the group ID or more than one correspondence between the UE ID or the UE index or the feedback index and the group ID.

At 304, the UE specific signalling or the group specific signalling may be used, for example, the network device may send the signalling.

FIG. 4 schematically illustrates a procedure 400 for obtaining the correspondence by the wireless communication device and supporting a feedback mechanism, according to various embodiments of the invention.

At 401, the device B (e.g., the wireless communication device 110) may receive signalling indicating the correspondence between the UE ID or the UE index or the feedback index and the UE group identification, e.g., the group RNTI.

At 402, in some embodiments, device B (e.g., the wireless communication device 110) itself may receive the signalling indicating the correspondence between the UE ID or the UE index or the feedback index of the UE B and the group ID. In some embodiments, the device B may receive the signalling indicating the correspondence between the UE ID or the UE index or the feedback index of the UE B and the group ID through the device C.

At 403, in some embodiments, the device B may receive the configuration of one correspondence between the UE ID or the UE index or the feedback index and the group ID or more than one correspondence between the UE ID or the UE index or the feedback index and the group ID.

In some embodiments, the device B may receive signalling from device C indicating one correspondence between the UE ID or the UE index or the feedback index and the group ID or more than one correspondence between the UE ID or the UE index or the feedback index and the group ID.

At 404, the UE specific signalling or the group specific signalling may be used.

In some embodiments, there may be one or more than one subgroups. The different subgroups may share the same group RNTI (e.g., receive the same group RNTI scrambled control channel), but with, for example, a different feedback configuration, or a different sidelink feedback channel resource configuration, or a different PUCCH configuration.

For example, different configurations may be different transmission formats, and the different transmission formats may use different sequence, different orthogonal code including the cyclic shift and/or the orthogonal cover code, different sequence application e.g., using the gold sequence as scrambling of payload or using modulated payload sequence or using payload status to select the sequence, different symbol number, etc. Different configurations may also be different or independent HARQ feedback timing configuration for different subgroup UEs.

For example, the HARQ feedback relaying or forwarding UE may have its own HARQ feedback timing and/or feedback formats configuration when relaying or forwarding its aggregated or concatenated HARQ feedback from its subgroup UE. Different configuration can also be that, for example, some UEs are configured to provide HARQ feedback, some do not provide, or some of the UEs are configured to feed back only NACK, or some of the UEs are configured to feedback both ACK and NACK. In some embodiments, the feedback channel resources may be multiplexed, for example, in order to reduce the feedback overhead for the groupcast or the unicast in the Uu link and/or the sidelink transmission, the feedback resource or the PUCCH resource or the feedback channel from different UE may be multiplexed together. To further reduce the feedback resource overhead, NACK only feedback (e.g. shared channel feedback described in solution 2) or subgroup or subset UE of one group can be configured or supported for the UE specific feedback channel resource configuration.

In some embodiments, in order to reduce the feedback overhead for the groupcast or the unicast in the Uu link and/or the sidelink transmission, the feedback resource or the PUCCH or the sidelink feedback channel from different UEs may be multiplexed together, for example, through sequence in the same time and frequency resource rather than each with its own time and frequency resource. The sequence may be or may include, for example, one or more than one of the sequence type, the base sequence, the pseudo random sequence, the cyclic shift, the orthogonal cover code, the scrambling ID, etc.

In some embodiments, the sequence may be the PN sequence with configured or associated scrambling ID or initialization value and/or the orthogonal cover code.

In some embodiments, the sequence may be the low PAPR sequence with base sequence and the configured or the associated cyclic shift and/or the orthogonal cover code and/or the scrambling ID, etc. Note that, the scrambling ID may also be used to create the cyclic shift or the orthogonal cover code. In some embodiments, the base sequence or the PN sequence may be used. Moreover, there may be two schemes described as scheme 1 and scheme 2. In the scheme 1 , for example, different base sequences or different PN sequences may be used for each UE, or the UE specific base sequence or the PN sequence may be used for the groupcast. In the scheme 2, for example, the common base sequence or the common PN sequence or the common sequence for the groupcast UE may be used. Moreover, group specific base sequence or group specific PN sequence or group specific scrambling ID configuration may be used.

Note that, the UE specific parameter configuration may be based on the common base sequence or the common PN sequence or the common sequence to create the UE specific resource or the sequence. In some embodiments, the combination of scheme 1 and scheme 2 may also be supported. For example, some of the UEs may share the same common sequence, some other UEs may share another common sequence. In some embodiments, two subgroups of UEs within one group may be configured with a different sequence. Moreover, the first and the second subgroup may have their own shared common sequence.

The scheme 1 may have a worse performance than the scheme 2 which may use some orthogonal code e.g., the cyclic shift (CS) or the orthogonal cover code (OCC) based on the common sequence. Moreover, the number of the available base sequence with good performance may be limited for scheme 1.

FIG. 5 schematically illustrates a system 500 for supporting the feedback mechanism for the groupcast transmission, according to various embodiments of the invention. The system 500 may be or may include the network device 100 and/or the wireless communication device 110.

The system 500 which may be or may include the network device 100 and/or the wireless communication device 110 may support the feedback mechanism (e.g., determine the UE specific feedback resource) for the groupcast transmission.

The system may determine the feedback channel resources and may further perform a multiplexing 502 on the determined feedback channel resources. However, the feedback channel resources, e.g. PUCCH resource 1, PUCCH resource 2, PUCCH resource 3, may not be multiplexed 501.

In the following, the procedures for supporting the feedback mechanism from the transmitter side (e.g., procedure 600) and the receiver side (e.g., procedure 700) are discussed.

FIG. 6 schematically illustrates a procedure 600 for supporting the feedback mechanism by the network device (from the transmitter side), according to various embodiment of the invention. At 601, in some embodiments, the device A (e.g., the network device 100) may determine the groupcast transmission feedback channel related parameters to one or more than one UE. Moreover, the device A may proceed to step 602.

In some embodiments, at step 601, the device A may determine the correspondence between the UE ID and/or the UE index and/or the feedback index and the UE group identification e.g., the group R TI. Moreover, the device may proceed to step 603.

At 602, in some embodiments, the high layer signalling may be used which may indicate the common groupcast transmission feedback channel parameters. In some embodiments, the lower layer signaling e.g. PHY signalling may be used which may indicate the dynamic groupcast transmission feedback channel resource indication values.

At 603, the device A may determine the UE specific groupcast transmission feedback channel resource.

At 604, the device A may determine the UE specific groupcast transmission feedback channel resource for the Uu link or the sidelink.

For example, the receiving UE e.g., the UE B may identify the groupcast transmission based on the indicated group ID. In addition, the device A may determine the UE specific feedback resource for the groupcast transmission, depending on the determined correspondence between the UE ID or the UE index and the group ID (e.g., determined at step 601), also the higher layer and the lower layer group specific signalling (e.g., sent at step 602). Alternatively, the receiving UE may also determine the UE specific feedback resource for the groupcast transmission, for example, based on the mapping of the UE ID, the feedback index and the group ID, and/or based on the higher layer and the lower layer group specific signalling, etc.

FIG. 7 schematically illustrates a procedure 700 for supporting the feedback mechanism from the side of the wireless communication device (the receiver side), according to various embodiment of the invention. At 701, in some embodiments, device B (e.g., the wireless communication device 110) may receive signalling of groupcast transmission feedback channel related parameters. Moreover, device A may proceed to step 602. In some embodiments, at step 701 , the device B may receive the signalling indicating the correspondence between the UE ID and/or the UE index and/or the feedback index and the UE group identification e.g., the group RNTI. Moreover, the device may proceed to step 603.

At 702, in some embodiments, the higher layer signalling may be used which may indicate the common groupcast transmission feedback channel parameters. In some embodiments, the lower layer signaling e.g. PHY signalling may be used which may indicate the dynamic groupcast transmission feedback channel resource indication values.

At 703, the device B may determine the UE specific groupcast transmission feedback channel resource.

At 704, the device B may determine the UE specific groupcast transmission feedback channel resource for the Uu link or the sidelink.

For example, the group specific feedback resource parameters may be indicated first with the group specific signalling which may indicate one or more than one parameters of the feedback channel format or the PUCCH format, the symbol configuration, the starting PRB, the resource pool configuration, the CS, the OCC, the scrambling ID, the UE index, the UE ID, the group ID, the sequence type, etc., which may be the same within the group or the subgroup. The group specific signalling may be the high layer signalling e.g., the RRC or the MAC CE, or both of them. Furthermore, different sets of group specific parameters may be configured with higher layer signalling, and the lower layer signalling which may indicate which set should be used. The predefined or the configured association between the data channel and/or the control channel and the feedback channel resource pool may be supported, e.g., when resource pool are configured for both data and control. The corresponding resource pool index may be signaled for the association between the data channel and/or the control channel and the feedback channel resource pool.

Furthermore, different subgroup may have different parameters or subgroup based parameter values e.g., subgroup 1 and 2 may have different PUCCH or sidelink feedback channel format, symbol configuration, PRB, resource pool, however, they may share the same downlink control information (DCI) or sidelink control information (SCI) indicator values for the feedback channel resource or the PUCCH resource indication.

The UE specific feedback resource for the groupcast transmission in the SL or the Uu link may be determined by one or more of the following schemes.

In scheme 1 , one or more than one parameters of starting position of the control channel or the PDCCH or the physical sidelink control channel (PSCCH), the group specific DCI or the group specific SCI indicated value, the group specific RRC or the MAC CE or both indicated feedback resource parameters, the UE index, etc. For the group based transmission, the UE index can be associated with the UE specific feedback resource in order.

In scheme 2, one or more than one parameters of the starting position of the control channel or the PDCCH or the physical sidelink control channel (PSCCH), the group specific DCI or the group specific SCI indicated value, the group specific RRC or the MAC CE or both of the indicated feedback resource parameters, the UE index, the offset k (the value of k can be configured), etc. For the group based transmission, the UE index can be associated with the UE specific feedback resource in order.

In scheme3 : one or more than one parameters of the starting position of the control channel or PDCCH or the PSCCH, the group specific DCI or the group specific SCI indicated value, the group specific RRC or the MAC CE or both of the indicated feedback resource parameters, the UE specific feedback index in the group specific DCI or the group specific SCI.

Note that, for scheme 1, 2 and 3, the lower layer signalling e.g., the PHY signalling, the group specific DCI or the group specific SCI carried by the corresponding control channel may also be, for example, transmitted, configured, received, etc. Moreover, the UE may determine UE specific feedback channel resource based on both higher layer and lower layer group specific signalling and/or the UE specific signalling. In scheme 1 , the feedback resource may be determined by one or more than one parameters of the starting position of the control channel or the PDCCH or the PSCCH, the group DCI or the group SCI indicated value, the group RRC or the group MAC CE or both of them, the indicated feedback resource parameters, the UE index, etc.

The group specific higher layer signalling e.g., the RRC indicates the feedback resource parameters including one or more than one of the feedback channel format, the symbol configuration, the PRB configuration, the resource pool configuration, the CS configuration, the OCC configuration, the scrambling ID configuration, etc. An example is shown in Table 1, where the feedback channel format, the symbol configuration, the PRB configuration, the CS configuration, the OCC configuration are configured. Note that, two formats are exemplarily shown here, other formats may also be applied. Different formats may support one or more than one configuration of the low PARR sequence, the PN sequence, the scrambling ID, the CS, the OCC, the symbol configuration, the PRB configuration, the resource pool configuration, the reed Muller coding, the polar coding, etc. Note, the PRB configuration may be indicated in the configured resource pool.

Table 1: Groupcast HARQ feedback channel resource parameters.

If the UE provides the HARQ feedback information in a feedback channel or the Uu or the SL PUCCH transmission, in response to detecting a DCI or SCI format, the UE determines a SL PUCCH/feedback (FB) channel resource with the index of r_FB channel, UE in_dex _> 0 £

a number of CCEs in a control resource set of a PDCCH or the sidelink control information (SCI) channel reception with the DCI/SCI format, the n_{CCE 0} is the index of a first CCE for the PDCCH or the PSCCH reception, and the A_FBR[ is a value of the Uu or the SL PUCCH/feedback resource indicator field in the DCI or SCI format, A_F' _BRI = A_FBRI + UEindex or A_F' _BRI= A_FBRI + UEindex + k (k is a value that may be configured).

For the groupcast or the multicast or the broadcast transmission, the UE specific feedback resource is at least based on the indicated value in the group specific LI signalling or the DCI signalling or the SCI signalling or the MAC CE signalling and the UE identification. Note usually LI signalling is faster than MAC CE signalling but also more sensitive on the bit overhead.

As one PRB can only provide several cyclic shift, when more CS required, more PRB is also required. Thus, some UEs may be multiplexed in the same PRB with different CS, some UEs may be multiplexed with different PRB with their respective CS. In the following, a procedure shows the PRB index determination and CS determination.

Also, the mapping of the A_F' _BRI and the PRB, the CS or implicitly the mapping of the UE index and the PRB, the CS may be determined. The frequency hopping for the PRB mapping may also be considered. Note that, the similar principle may be applied when the OCC or the scrambling ID or the CS or any combination of them are configured, e.g., as the feedback resource. In some embodiments, if the [r_FBchannei · 2/N\ = 0

• The UE may determine the PRB index of the feedback channel/Uu/SL PUCCH transmission in the first hop as the PRB index of the feedback channel/Uu/SL PUCCH transmission in the second hop as the N_cs is the total number of initial cyclic shift indexes in the set of cyclic shift indexes. The RB_B^ ^set is the configured RB offset in the configured bandwidth part (BWP) or the resource pool. The N§w^e is the bandwidth of the BWP or the resource pool. • The UE may determine the cyclic shift index in the set of the cyclic shift indexes a^{s r}FB channel mod N_cs. In some embodiments, if the [r_FBchannei · 2/N\ = 1

• The UE may determine the PRB index of the feedback channel or the PUCCH transmission in the first hop as the — [(r_FB channel— iV/2)/iV_CsJ and the PRB index of the feedback channel or the PUCCH transmission in the second hop as the .

• The UE may determine the cyclic shift index in the set of cyclic shift indexes as the (r_FB channel ^~ N /2)mod N_cs. For scheme 2 (e.g., compared to scheme 1) a configurable resource offset is included in the feedback channel resource parameter in order to enable a more flexible resource configuration. The feedback channel resource may be determined by one or more than one of the starting position of the PDCCH or the PSCCH, the group DCI or the group SCI indicated value, the group RRC or the group MAC CE or both of them, the indicated feedback resource parameters, the UE index, a resource offset k, etc.

The group specific high layer signalling e.g., the RRC may indicate the feedback resource parameters including one or more than one of the feedback channel format, the symbol configuration, the PRB configuration, the CS configuration, the OCC configuration, the scrambling ID configuration, the resource offset, the sequence type} . An example is shown in Table 2, where the feedback channel format, the symbol configuration, the PRB configuration, the CS configuration, the OCC configuration are configured. The resource offset may also be additionally configured. In some embodiments, the A'_PRI = A_PR[ + UEindex + k. Where the k is a value that may be configured. Moreover, for the groupcast or the multicast or the broadcast transmission, the UE specific feedback resource may be determined based on the indicated value in the group specific low layer signalling or the DCI signalling or the SCI signalling and the UE identification and the configured offset. The UE identification may be the configured UE index within the groupcast or the multicast or the broadcast group or the subgroup. The configured offset may be the group or the subgroup common value being configured by the group specific singling or the UE specific signalling.

In some embodiments, the OCC may also be configured with more options. As shown in the Table 2, with more than one available OCC, more feedback channel resources may be supported. For example, compared to only one OCC or no OCC, the m available OCC may give rn*r_FBchannel feedback resource. The number of the available OCC may be denoted as the N_occ. Note that, the similar principle is applied when the scrambling ID is used. And the combination of one or more than one of the CS, the OCC, the scrambling ID may be supported.

In some embodiments, the UE can obtain the r_FB channel, UE index according to the above described scheme 1 or scheme2.

In some embodiments, if the [r_FBchannei · 2/N\ = 0

• The UE may determines the PRB index of the feedback channel/SL PUCCH transmission in the first hop as RB°^fJ^set + [r_FB c_hanne_l /Wes ^Nocc) J and the PRB index of the feedback channcl/SL PUCCH transmission in the second hop the N_cs is the total number of initial cyclic shift indexes in the set of cyclic shift indexes. The RB° ^^set is the configured RB offset in the configured BWP or the resource pool. The N§%^e is the BWP or the resource pool.

• The UE may determine the cyclic shift index in the set of the cyclic shift indexes a^{s r}FB channei^m°d Wes Nocc) mod N_cs, the UE may determine the OCC index in the set of OCC indexes as [r_FB channeled ( N_cs 1V_0CC)/1V_CSJ.

In some embodiments, if the If [r_FBchannei 2/1VJ = 1 • The UE may determine the PRB index of the PUCCH transmission in the first hop as the the PRB index of the PUCCH transmission in the second hop as RB^^set +

[(TFB channel ^~ N /2)/ ( N_cs · N_occ) J .

• The UE may determine the cyclic shift index in the set of the cyclic shift indexes as LO_FB channel ^~ N /2)mod ( N_cs N_occ) mod N_cs\, the UE may determine the OCC index in the set of OCC indexes as LO_FB channel ^~ N /2)mod (N_cs Nocc)/Ncs\ -

In some embodiments, any combination of the CS, the OCC and the scrambling ID may be configured to support the groupcast feedback resource configuration. For example, the may CS be replaced with the scrambling ID in the above example, or the CS be replaced with the scrambling ID and may further switch (e.g., change) the scramble ID and the OCC’s position in the above example, etc.

In some embodiments, when one or more than one of the CS, the OCC and the scrambling ID may be configured as the groupcast or the multicast or the broadcast feedback resource. Moreover, the UE may determine the feedback resource index of each factor based on the addition of the configured or the available or the maximum index number of more than one factor and at least one factor which is, for example, configured, determined, available, or is maximum index number, or the like.

Table 2: Groupcast HARQ feedback resource parameters.

For the scheme 1, a correspondence or mapping table is exemplary shown (Table. 3) between the UE index and the FB resource parameter delta and delta’. The UE specific FB resource parameter is determined based on the delta value with 4 bits SCI indication and the corresponding UE index.

Table 3

Correspondence between UE index and the FB resource parameter. For scheme 2, a correspondence or mapping table is exemplarily shown among the UE index, an offset value and the FB resource parameter delta and delta’. The UE specific FB resource parameter is determined based on the delta value with 3 bits SCI indication, the corresponding UE index and a configured offset k. The value of the k is determined as 0 for the Table 5, and the value of the k is determined as 2 for the Table 5.

Table 4 Correspondence among UE index, offset k and the FB resource parameter.

Table 5 Correspondence among UE index, offset k and the FB resource parameter.

For scheme 3, the group specific common parameters may be determined, as discussed above. However, the UE specific signalling may configure the correspondence between its feedback index and the group ID. When one group DCI or SCI or MAC CE is used, the feedback index is configured by the UE specific signalling which may define the bit position of this UE’s feedback indication in the group DCI or the group SCI or the group specific MAC CE. In some embodiments, the group specific signalling may carry the UE specific feedback channel resource indicator. Assuming the feedback position is N (enumerate from 0), each PRB support Q feedback resource e.g., including both the CS and the OCC. Each feedback index may correspond to M bits for the UE specific feedback resource indication, then, the UE or the transmitter may determine the feedback resource

PRB according to: it may determine its feedback resource in the indicated PRB, for example, according to the M bits indication in the group DCI or the group SCI. In some embodiments, the subgroup based feedback channel may be supported for the groupcast or the multicast or the broadcast transmission. For example, the UEs may receive the same groupcast transmission e.g., with the same group R TI, which may have different feedback channel configurations. Moreover, different channel condition may exist for the UEs within one group. For the UEs with a poor received signal quality, a more robust feedback channel configuration may be preferred e.g., with a long feedback channel format or more symbols, they may belong to one subgroup. However, for the UEs with relative good channel condition, a short feedback channel format or fewer symbols may be configured with a lower feedback delay or no feedback being configured, they may belong to another subgroup. The transmission timing for short feedback channel format and for a long feedback channel format or for different subgroups may also be different. In some embodiments, the orthogonal resources may be configured for a different subgroup. The subgroup configurations may be in the UE specific signalling or the group specific signalling or both of them. The UE may be configured with the UE index within the subgroup to get the UE specific feedback channel resource configuration, according to the above description.

In some embodiments, a feedback channel resource multiplexing may be supported among different UEs by supporting orthogonal sequence or code multiplexing with time sequencing and/or a frequency sequencing and/or a code sequencing. For example, as the number of code per PRB or per PRB or per PRB/RB group is limited, the code selection or allocation can be first within RB or RB group based on configured code sequence, then among RB or RB group based on configured frequency or RB or RB group sequence, alternatively finally among slots or mini-slots based on configured time sequence.

In some embodiments, a feedback channel resource multiplexing may be supported among different UEs by supporting orthogonal sequence or code multiplexing, and/or supporting a NACK only feedback or a part of the UEs within the group or the UEs within the subgroup for feedback in UE specific feedback channel resource, as it is described with the UE specific feedback resource configuration.

In some embodiments, the receiving node e.g., the gNB or the RSU or the RN or the UE may obtain the UE specific feedback information based on the UE specific feedback resource. Moreover, it may be determined which UE incorrectly decode the groupcast transmission. For example, the UE specific retransmission may be configured to help the groupcast or the multicast or the broadcast data decoding.

In some embodiments, the UE specific feedback resource configuration may also be configured for the UE specific retransmission. For example, a retransmission number and the corresponding transmission and feedback resource are configured for sidelink, and then HARQ ACK/NACK is feedback to the network UE when sidelink gets to the maximum retransmission number or ACK is received. Another example, the unicast assisted groupcast retransmission may be configured. A unicast assisted groupcast retransmission may be included in the signalling for the UE. Further an identification on the unicast assisted groupcast retransmission may be included in the signalling for the UE to do the soft combining of the initial groupcast transmission and the unicast retransmission. In addition, the HARQ process ID correspondence or the alignment between the groupcast/multicast transmission and the unicast assisted retransmission may be supported. In some embodiments, the unicast transmission may use the same HARQ process ID or a configured mapping or a correspondence between the groupcast or the multicast or the broadcast HARQ ID and the unicast HARQ ID as the groupcast or the multicast or the broadcast transmission. Furthermore, the UE specific beamforming with the UE specific RS quasi co-location (QCL) assumption may be configured for the unicast assisted groupcast retransmission.

Note that, the above UE specific feedback resource determination for the groupcast transmission may also be applied to the unicast transmission. In some embodiments, the group ID may be equivalent to the UE ID, the group specific configuration and the related parameters may become UE specific configuration and the related parameters.

In some embodiments, the subgroup based shared channel feedback for the groupcast or the multicast or the broadcast transmission may be supported. As described above, the UEs may receive the same groupcast or the multicast or the broadcast transmission e.g., with the same group RNTI which may be classified as different subgroups. Moreover, different subgroups may have different channel configurations and different feedback configurations. Within the same subgroup, the shared feedback channel may be configured. Further, the HARQ NACK only feedback in the shared channel or the independent shared channel may be configured for the HARQ ACK and the NACK. An example is shown in FIG. 8, Table 6, and Table7.

FIG. 8 schematically illustrates a system 800 for supporting a subgroup based shared feedback channel resource, according to various embodiments of the invention. Where two vehicle subgroups 801, 802 of subgroup 1 (including UE2 and UE3) 801 and subgroup 2 (including UE4 and UE5) 802 are configured, and furthermore, different symbol configurations and orthogonal resources are configured for the two subgroups. Another case is that some of the UEs in the group or the UEs within one subgroup may be configured with the HARQ feedback. For example, only UE with a bad channel condition e.g., the signal power below a certain threshold may be configured with the HARQ feedback or some subgroups may be configured with the HARQ feedback.

Table 6 Subgroup based shared channel feedback, only NACK.

Table 7 Subgroup based shared channel feedback, both ACK and NACK.

In some embodiments, a relayed feedback for the groupcast, the multicast, the broadcast and the unicast transmission may be supported.

For example, in some embodiments, the sidelink feedback may be sent from one or more than one UE to one selected or configured UE. In some embodiments, the sidelink feedback may be sent from one or more than one UE to one selected or configured UE, then, to the selected or the configured leading UE. In some embodiments, the sidelink feedback may be sent from one or more than one UE to one selected or configured UE, then to the selected or the configured leading UE, then to the gNB or the RSU. The sidelink feedback may be sent from one or more than one UE to the gNB or the RSU. The feedback information (e.g., the feedback message) may include the sidelink feedback information or the Uu link feedback information or both of them.

The selected or the configured UE may be configured by, e.g., the gNB, the RSU, the RN or another UE. The leading UE may be configured by, e.g., the gNB, the RSU, the RN. In some embodiments, especially for in coverage scenario, the gNB or the RSU is responsible for the scheduling, however, it may be possible to configure the certain UE for the scheduling within the configured resources by the gNB or the RSU or the RN.

Moreover, when the feedback information is the HARQ feedback, the selected or the configured UE or the leading UE may do an aggregated or a concatenated processing. Afterwards, it may further, for example, transmit or relay or forward it to a further node. For the aggregated processing, it may be a bundled ACK and/or the NACK operation or “AND” operation of ACK and/or NACK received from more than one link or more than one UE. For example, when at least one NACK received, the selected UE or the leading UE may forward the NACK to the further node. When all the received feedback is ACK, UE may forward the ACK to the further node. The further node may be the UE or the gNB or the eNB or the RSU or the RN.

The advantages of aggregating or bundling ACK and NACK across link includes less transmission occasion required for the feedback especially for the TDD system which means a low latency, and the reducing the feedback overhead.

In addition, enabling or disabling of the aggregating or the bundling ACK and NACK across the link or between the UEs or among the UEs may further be configured. For example, the UEs or their feedback that may be aggregated or bundled, may further be configured. For example, it may be the subgroup or the group based aggregation or the bundling. For the concatenated processing which may apply to both of the unicast and the multicast feedback processing, both sidelink only and combined sidelink and Uu link, a predefinition or pre-configuration or signalling may be configured on the feedback information position in the concatenated reporting for each of the UE or each group of the UEs. The feedback configuration signalling may include one or more than one of, for example, the feedback information for the unicast, the feedback information for the groupcast or the multicast or the broadcast, the feedback information position for the unicast, the feedback information position for the groupcast or the multicast or the broadcast, the UE ID, the group ID, the destination ID, the source ID, the feedback channel format or the PUCCH format, the symbol configuration, the starting PRB, the resource pool configuration, the CS configuration, the OCC configuration, the pseudo random sequence configuration, etc. Moreover, based on the configuration, the UE or the RSU or the RN may process the concatenation of the received feedback information to the following node.

In some embodiments, the sidelink feedback in the Uu link may be used. Moreover, the UE may only feed back SL HARQ ACK/NACK and/or sidelink channel state information (CSI) in the Uu link, and a dedicated resource may be allocated for the sidelink feedback transmission. Furthermore, when both the Uu feedback and the SL feedback coexist in the Uu link, they may jointly be transmitted in the predefined or the configured order. The order may be (SL feedback, Uu feedback}; or (Uu feedback, SL feedback} . For example, (SL ACK/NACK, Uu ACK/NACK}, or (Uu ACK/NACK, SL ACK/NACK}, Note that, NACK only or ACK only or both ACK and NACK from SL may be supported based on one or more than one of above combinations. Furthermore, when the CSI is transmitted at the same time, the order may be first the HARQ feedback of Uu link and sidelink, then, the CSI feedback of the Uu link and the sidelink. For example, (Uu HARQ feedback, SL HARQ feedback, Uu link CSI, SL CSI feedback} or (SL HARQ feedback, Uu HARQ feedback, SL CSI feedback, Uu CSI feedback} . In some embodiments, the scheduled time or transmission time for the feedback ordering may be used. Another method is to use the configured ordering or the defined ordering, as discussed above. In some embodiments, there may be more than one HARQ feedback bits from the SL feedback as there may be more than one sidelink communication. Moreover, the joint transmission may be done or the joint coding may be transmitted with the sequence selection or the CS selection or the modulated symbol selection. For example, (Uu ACK/NACK, SL ACK/NACK} : {0,0} correspond to CS 1; {0,1 } correspond to CS 2; {1,0} correspond to CS 3; {1,1 } correspond to CS 4; Or {0,0} correspond to modulated symbol 1, {0,1 } correspond to modulated symbol 2; {1,0} correspond to modulated symbol 3; {1,1 } correspond to modulated symbol 4. Furthermore, when the UCI including both Uu and SL feedback and are mapped to resource elements, the higher priority bits may be mapped to the REs more close to RS, in order to obtain a better performance. The priority or mapping position may be configured. For example, the SL HARQ feedback may have higher priority than the Uu link HARQ feedback or the CSI feedback. As the SL feedback to the network may include both the Uu link and the SL with more latency. The SL HARQ feedback bits may be mapped close to the DMRS symbol.

LIG. 9 shows a method 900 according to an embodiment of the invention for supporting a UE feedback mechanism to a unicast or a groupcast or a multicast or a broadcast transmission. The method 900 may be carried out by the device 100, as it described above.

The method 900 comprises a step 901 of determining one or more of feedback channel resources 101 for one UE 110 or a subgroup or a group of UEs 110, wherein each determined feedback channel resource 101 is a UE specific feedback channel resource or a shared feedback channel resource for one UE 110 or a group or a subgroup of the UEs 110.

The method 900 further comprises a step 902 of sending, to a UE 110 or a subgroup or a group of the UEs 110, a UE specific or subgroup specific or group specific signalling 102 comprising one or more parameters 103 being indicative of at least one of the determined feedback channel resources 101.

FIG. 10 shows a method 1000 of a wireless communication device 110, according to an embodiment of the invention. The method 1000 may be carried out by the wireless communication device 110, as it described above.

The method 1000 comprises a step 1001 of receiving, from a network device 100, a UE specific signal 102 or a subgroup specific signal 102 comprising one or more parameters 103 being indicative of at least one determined feedback channel resource 101. The method 1000 further comprises a step 1002 of sending one or more feedback messages 111 to the network device 100 and/or another node using the at least one determined feedback channel resource 101, wherein the at least one determined feedback channel resource 101 is a UE specific feedback channel resource or a shared feedback channel resource for a subgroup of the UEs 110.

The present invention has been described in conjunction with various embodiments as examples as well as implementations. However, other variations can be understood and effected by those persons skilled in the art and practicing the claimed invention, from the studies of the drawings, this disclosure and the independent claims. In the claims as well as in the description the word“comprising” does not exclude other elements or steps and the indefinite article“a” or“an” does not exclude a plurality. A single element or other unit may fulfill the functions of several entities or items recited in the claims. The mere fact that certain measures are recited in the mutual different dependent claims does not indicate that a combination of these measures cannot be used in an advantageous implementation.

Claims

1. Network device (100) for supporting a User Equipment, UE, feedback mechanism to a unicast or a groupcast or a multicast or a broadcast transmission, the network device (100) being configured to:

determine one or more of feedback channel resources (101) for one UE (110) or a subgroup or a group of UEs (110),

wherein each determined feedback channel resource (101) is a UE specific feedback channel resource or a shared feedback channel resource for one UE (110) or a group or a subgroup of the UEs (110); and

send, to a UE (110) or a subgroup or a group of the UEs (110), a UE specific or subgroup specific or group specific signalling (102) comprising one or more parameters (103) being indicative of at least one of the determined feedback channel resources (101).

2. Network device (100) according to claim 1, further configured to

determine a correspondence between a group Identification, ID, and/or a subgroup ID, with one or more of:

a UE index;

a UE identification;

a feedback index.

3. Network device (100) according to claim 2, wherein

the UE specific signalling (102) or the subgroup specific signalling (102) or the group specific signalling (102) is sent based on the determined correspondence.

4. Network device (100) according to one of the claims 1 to 3, wherein

each determined feedback channel resource (101) is configured to support one or more of:

a feedback to a destination device;

a relayed feedback via a relayed device to a destination device.

5. Network device (100) according to one of the claims 1 to 4, wherein

the UE specific signalling (102) and/or group specific signalling (102) and/or subgroup specific signalling (102) comprises one or more of: a higher layer signalling indicating a group specific or subgroup specific feedback channel parameters; and/or

a lower layer signalling indicating a group specific or subgroup specific feedback channel resource indication value; and/or

a higher layer signalling indicating an association between UE ID or UE index and group ID or subgroup ID; and/or

a higher layer signalling indicating an association between UE ID or UE index and feedback index carried in a group or subgroup specific lower layer signalling.

6. Network device (100) according to one of the claims 1 to 5, further configured to multiplex two or more feedback channel resources (101) based on a time sequencing and/or a frequency sequencing and/or a code sequencing.

7. Network device (100) according to one of the claims 1 to 6, further configured to receive one or more feedback messages from one or more of the UEs (110), wherein the feedback message of each UE (110) is received in the determined UE specific feedback channel resource (101) or the determined shared feedback channel resource (101).

8. Network device (100) according to claim 7, wherein

the received feedback message comprises a negative acknowledgement, NACK and/or an acknowledgement, ACK.

9. Network device (100) according to one of the claims 1 to 8, wherein

each feedback channel resource (101) is determined by one or more of:

a starting position of a Physical Downlink Control Channel, PDCCH, a starting position of a Physical Sidelink Control Channel, PSCCH, a resource pool configuration of data channel;

a resource pool configuration of feedback channel and/or control channel a predefined or configured association between data channel and/or control channel and feedback channel resource pool

a group specific Downlink Control Information, DCI, indicated value, a group specific Sidelink Control Information, SCI, indicated value, a group specific Radio Resource Control, RRC, and/or MAC Control Element, MAC CE;

an indicated feedback resource parameters

a group specific high layer signalling indicated feedback resource parameters,

an UE index,

an offset k.

a feedback index

a group ID

a subgroup ID

a sequence type

a cyclic shift value

an OCC index

a scrambling ID

a transmission type of unicast or groupcast or both.

10. Method (900) for supporting a User Equipment, UE, feedback mechanism to a unicast or a groupcast or a multicast or a broadcast transmission, the method (900) comprising:

determining one or more of feedback channel resources (101) for one UE (110) or a subgroup or a group of UEs (110),

sending, to a UE (110) or a subgroup or a group of the UEs (110), a UE specific or subgroup specific or group specific signalling (102) comprising one or more parameters (103) being indicative of at least one of the determined feedback channel resources (101).

11. Wireless communication device (110), UE, configured to

receive, from a network device (100), a UE specific signalling (102) or a subgroup specific signalling (102) or a group specific signaling (102) comprising one or more parameters (103) being indicative of at least one determined feedback channel resource (101); and send one or more feedback messages (111) to the network device (100) and/or another node using the at least one determined feedback channel resource (101),

wherein the at least one determined feedback channel resource (101) is a UE specific feedback channel resource (101) or a shared feedback channel resource (101) for a group or a subgroup of the UEs (110).

12. Wireless communication device (110) according to claim 11, wherein

the UE specific signalling (102) or the subgroup specific signalling (102) or the group specific signaling is indicative of a correspondence between a group Identification, ID, with one or more of:

a UE index;

a UE identification;

a feedback index.

13. Wireless communication device (110) according to claim 11 or 12, wherein

the sent feedback message comprises a negative acknowledgement, NACK and/or an acknowledgement, ACK..

14. Wireless communication device (110) according to one of the claims 11 to 13, wherein

each feedback channel resource (101) is determined by one or more of:

a resource pool configuration of feedback channel and/or control channel, a predefined or configured association between data channel and/or control channel and feedback channel resource pool,

a group Downlink Control Information, DCI, indicated value, a group Sidelink Control Information, SCI, indicated value, a group specific Radio Resource Control, RRC, and/or MAC Control Element, MAC CE;

an indicated feedback resource parameters,

a group specific high layer signaling indicated feedback resource parameters, an UE index,

an offset k,

a feedback index,

a group ID,

a subgroup ID,

a sequence type,

a cyclic shift value,

an OCC index,

a scrambling ID,

a transmission type of unicast or groupcast or both.

15. Wireless communication device (110) according to one the claims 11 to 14, further configured to

send, when being a relaying UE, an aggregated Hybrid Automatic Repeat Request, HARQ, feedback message to another node, wherein the aggregated HARQ feedback message comprises a NACK, if at least one feedback message is NACK.

16. Wireless communication device (110) according to one the claims 11 to 15, further configured to

send, when being a relaying UE, a concatenated HARQ feedback message to another node, wherein the concatenated HARQ feedback message comprises one or more feedback messages received from a UE or the subgroup of UEs or the group of UEs.

17. Method (1000) of a wireless communication device (110), UE, the method (1000) comprising:

receiving (1001), from a network device (100), a UE specific signalling (102) or a subgroup or group specific signalling ( 102) comprising one or more parameters (103) being indicative of at least one determined feedback channel resource (101); and

sending (1002) one or more feedback messages (111) to the network device (100) and/or another node using the at least one determined feedback channel resource (101), wherein the at least one determined feedback channel resource (101) is a UE specific feedback channel resource or a shared feedback channel resource for a UE or a group of the UEs (110) or a subgroup of the UEs (110).