CN114499771B

CN114499771B - Feedback and retransmission method and device for ACK/NACK information of MBS

Info

Publication number: CN114499771B
Application number: CN202011271015.3A
Authority: CN
Inventors: 魏立梅; 袁乃华; 陈迎; 周志宏; 朱玉梅; 范晨
Original assignee: Chengdu TD Tech Ltd
Current assignee: Chengdu TD Tech Ltd
Priority date: 2020-11-13
Filing date: 2020-11-13
Publication date: 2023-07-18
Anticipated expiration: 2040-11-13
Also published as: CN114499771A

Abstract

The invention provides a feedback and retransmission method and a device of ACK/NACK information of MBS, when gNB determines to transmit MBS through MPT bearing, configuration is carried out on PTM bearing of MBS, so that gNB can transmit TB of MPT bearing through a plurality of HARQ processes in parallel, a PUCCH resource pool is configured for PTM bearing, UE receiving PTM bearing feeds back the ACK/NACK information of TB of PTM bearing through PUCCH in the PUCCH resource pool, gNB retransmits the TB with failed transmission or retransmits code groups with failed transmission in the TB according to the ACK/NACK information of the TB of PTM bearing. The method enables the MBS based on MPT bearing transmission to retransmit the TB with failed transmission, so that the MBS meets QoS requirements.

Description

Feedback and retransmission method and device for ACK/NACK information of MBS

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a method and an apparatus for feeding back and retransmitting ACK/NACK information of a multicast broadcast service (Multicast and Broadcast Service, abbreviated MBS).

Background

With rapid development of wireless communication technology, a New Radio Access (NR) system is widely used, and the NR system can provide multicast and broadcast services (Multicast and Broadcast Service, MBS) in addition to unicast services.

FIG. 1 is a schematic diagram of an MBS architecture in an NR system, as shown in FIG. 1, comprising: MBS server, 5G core network (5G core, 5GC for short), new generation radio access network (New Generation Radio Access Network, NG-RAN for short) and multiple UEs, NG-RAN being a base station employing NR, gNB for short. The MBS server provides broadcast/multicast services. For each broadcast/multicast service, the MBS server transmits user plane data and control plane information of the service to the 5GC through a user plane interface and a control plane interface with the 5GC, respectively. The 5GC provides a user plane data transmission path and a control plane information transmission path for the broadcast/multicast service from the MBS server, through which user plane data and control plane information of the broadcast/multicast service are transmitted to the NG-RAN (gNB), respectively. The gNB determines NR cells for transmitting the broadcast/multicast service according to the control plane information of the broadcast/multicast service from the core network, and transmits the broadcast/multicast service in the corresponding NR cells.

For a broadcast service, the gNB transmits the broadcast service in a corresponding NR cell in a Point-to-multipoint (PTM) bearer, and broadcasts PTM configuration information of the broadcast service, and User Equipment (UE) establishes a PTM bearer according to the PTM configuration information of the broadcast service, and receives the broadcast service through the PTM bearer. For the multicast service, before the corresponding NR cell transmits the multicast service, the gNB makes the UE allowed to receive the multicast service enter a radio resource control (Radio Resource Control, abbreviated as RRC) connection state through paging, determines to transmit the multicast service in a PTM bearer and/or a Point-to-Point (PTP) bearer according to the number and location information of the UE received in the cell, and sends the PTM/PTP configuration information to the corresponding UE through dedicated signaling, and the UE establishes a PTM/PTP bearer according to the PTM/PTP configuration information of the multicast service, and receives the multicast service through the bearer.

The NR system is required to meet the service quality (Quality of Service, qoS) requirement of MBS in the MBS transmission process. When the multicast service is transmitted by PTP bearing, the QoS requirement of the multicast service can be met according to the method for meeting the QoS requirement of the common service. However, for MBS transmitted with PTM bearer, since the UE does not feed back acknowledgement/NON-acknowledgement (ACK/NACK) information of a Transport Block (TB) on the PTM bearer when receiving the MBS through the PTM bearer, the gNB cannot know whether the UE satisfies QoS requirements of the MBS for the reception of the MBS.

Disclosure of Invention

The invention provides a feedback and retransmission method and a device of ACK/NACK information of MBS, which enable the MBS based on MPT bearing transmission to retransmit the failed TB so as to enable the MBS to meet QoS requirements.

The first aspect of the present invention provides a feedback and retransmission method for ACK/NACK information of MBS, applied to a gNB, the method comprising:

for any multicast broadcast service MBS, when gNB determines to transmit the MBS through point-to-multipoint PTM bearer, configuring a group radio network temporary identifier G-RNTI and a semi-static SPS G-RNTI for the MBS, determining a bandwidth part BWP of the PTM bearer for transmitting the MBS, and configuring a service data adaptation protocol SDAP entity, a packet data convergence protocol PDCP entity and a radio link control RLC entity for the PTM bearer of the MBS;

Dividing K radio bearers RB included in the PTM bearer into: K1P-RBs and/or K-K1 NP-RBs, wherein each P-RB has the characteristics of periodic transmission and fixed data quantity transmitted each time. The RB which is not the P-RB is NP-RB, the PTM bearer is split into K1P-PTM bearers and/or 1 NP-PTM bearer according to the RB type, each P-RB has a unique P-PTM bearer for transmitting the RB, and 1 NP-PTM bearer is used for transmitting all NP-RBs;

when the MBS is a multicast service or the MBS is a broadcast service, but User Equipment (UE) receiving PTM bearing of the MBS is in a Radio Resource Control (RRC) connection state, a Media Access Control (MAC) layer determines each beam coverage area for transmitting the PTM bearing according to the position of the UE receiving the RRC connection state of the PTM bearing, and determines a beam adopted when the PTM bearing is transmitted in each beam coverage area for transmitting the PTM bearing;

transmitting each P-PTM bearer and NP-PTM bearer of the PTM bearer on a BWP transmitting the PTM bearer;

and for each P-PTM bearer and NP-PTM bearer of the PTM bearer, the gNB summarizes NACK information of the TB of the P-PTM/NP-PTM bearer fed back by the UE, and retransmits the TB of the P-PTM/NP-PTM bearer.

In an exemplary manner, the method further comprises:

Configuring semi-static resources for the P-PTM bearer for periodically sending the P-PTM bearer, wherein the semi-static resources comprise semi-static physical downlink shared channel PDSCH resources and semi-static physical uplink control channel PUCCH resources;

the configuration information of the semi-static resource comprises: period T, semi-static PDSCH resource allocation information and semi-static PUCCH resource allocation information;

the semi-static PDSCH resource configuration information includes: initial radio frame bias, initial time slot bias, repeated transmission times N1 of PDSCH, wave beam quantity B2 adopted when transmitting PDSCH, and frequency resource occupied by PDSCH;

the semi-static PUCCH resource configuration information includes: timing difference d, the repetition transmission times of PUCCH (physical uplink control channel) N2, a PUCCH resource pool and time-frequency resources occupied by the PUCCH, wherein the PUCCH resource pool comprises M PUCCHs;

the sending each P-PTM bearer of the PTM bearer on the BWP sending the PTM bearer includes:

and sending each P-PTM bearer of the PTM bearer according to the semi-static PDSCH resource configuration information.

In an exemplary manner, the sending each P-PTM bearer of the PTM bearers according to the semi-static PDSCH resource configuration information includes:

in each period corresponding to semi-static PDSCH resources, the MAC layer divides B2N 1 PDSCH opportunities allocated to the P-PTM bearer into N1 groups, and forms a group every B2 opportunities from a PDSCH opportunity with subscript 0, and divides B2N 2 PUCCH opportunities allocated to the P-PTM bearer into N2 groups, and forms a group every B2 opportunities from a PUCCH opportunity with subscript 0;

In each period of the semi-static PDSCH resource, the MAC layer generates a TB by the MAC PDU borne by the P-PTM, and determines a hybrid automatic repeat request HARQ process adopted by the TB;

when the MBS is a broadcast service, B2 = B, B represents the number of beams adopted when SS/PBCH BLOCK is transmitted, in each period corresponding to semi-static PDSCH resources, the MAC layer adopts allocated PDSCH resources to transmit PDSCH at the B-th PDSCH occasion in each group of PDSCH occasions, adopts beam B when transmitting the PDSCH, carries the TB on the PDSCH, and adopts SPS G-RNTI when bit scrambling, B = 1, …, and B2;

when the MBS is a multicast service, or when the MBS is a broadcast service and UEs receiving the PTM bearer are in an RRC connection state, b2=b, the MAC layer transmits PDSCH using allocated PDSCH resources at the (i) th PDSCH occasion in each set of PDSCH occasions, and uses Beam (i) when transmitting the PDSCH, the PDSCH carries the TB thereon, and uses SPS G-RNTI when bit scrambling, i=1, …, B1, and when B1< B, there is no need to transmit PDSCH in the remaining PDSCH occasions in each set of PDSCH occasions;

when the MBS is a multicast service, or when the MBS is a broadcast service and the UE receiving the PTM bearer is in an RRC connection state, b2=b1, the MAC layer transmits a PDSCH using allocated PDSCH resources in the ith PDSCH occasion in each group of PDSCH occasions, uses Beam (i) when transmitting the PDSCH, carries the TB on the PDSCH, uses SPS G-RNTI when bit scrambling, and notifies the UE of the Beam coverage area of the PTM bearer through a DCI format on the MAC CE or PDCCH when B1< B, or when the value of B1 changes.

In an exemplary manner, in each period corresponding to the semi-static PDSCH resources, the frame number SFN of the starting radio frame satisfies the following equation:

(SFN)MOD(T)＝0

in each period corresponding to the semi-static PDSCH resources, the frame number SFN of the starting radio frame for transmitting PDSCH satisfies the following equation:

(SFN)MOD(T)＝SFN_OFFSET

the ID of the HARQ process used by the TB transmitted in each period corresponding to the semi-static PDSCH resource satisfies the following equation:

ID＝INT(SFN/T)MOD H；

where MOD denotes modulo two integers, INT (X) denotes rounding a real number X, sfn_offset denotes a starting radio frame OFFSET for transmitting PDSCH, T denotes a period of PDSCH resources, and H denotes the number of HARQ processes.

In an exemplary manner, the NP-PTM bearer of the PTM bearer is sent over a BWP that sends the PTM bearer, comprising:

and each time the MAC layer schedules the NP-PTM bearer, allocating Physical Downlink Control Channel (PDCCH) resources, PDSCH resources and PUCCH resources for the NP-PTM bearer, and forming a TB by MAC PDU carried by the NP-PTM according to the allocated PDSCH resources, wherein the NP-PTM bearer is used for transmitting all NP-RBs. The MAC PDU carried by the NP-PTM is formed by multiplexing MAC SDUs on each NP-RB, the MAC layer selects an idle HARQ process for the TB, and the TB is sent through the process;

The PDCCH resources allocated for the NP-PTM bearer comprise B2 x N3 PDCCH opportunities, N3 is the repeated transmission times of the PDCCH, the B2 x N3 PDCCH opportunities are divided into N3 groups, and each group comprises B2 continuous PDCCH opportunities;

the PDSCH resources allocated for the NP-PTM bearer include B2 x N3 PDSCH occasions, N3 is the number of repeated transmissions of the PDSCH, the B2 x N3 PDSCH occasions are divided into N3 groups, each group including B2 consecutive PDSCH occasions;

the PUCCH resources allocated for the NP-PTM bearer include B2×n4 PUCCH occasions, the time-frequency resources allocated for the PUCCH in each PUCCH occasion are the same, N4 is the number of repeated transmissions of the PUCCH, the time-frequency resources of the B2×n4 PUCCH occasions are the same, the B2×n4 PUCCH occasions are divided into N4 groups, and each group includes B2 continuous PDSCH occasions;

the PUCCH resources allocated for the NP-PTM bearer are formed by B2 x N4 PUCCH opportunities, the B2 x N4 PUCCH opportunities are divided into N4 groups, each group comprises B2 continuous PUCCH opportunities, N4 is the repetition transmission times of PUCCH, the same time-frequency resources are allocated for the PUCCH in each PUCCH opportunity, the time-frequency resources are determined by a starting symbol index 1, the number of symbols 1, PRB bias 1 and CS index set 1, the PUCCH sent on the allocated time-frequency resources in each PUCCH opportunity is given by a PUCCH resource pool, the PUCCH resource pool is formed by M PUCCHs, and each PUCCH adopts a format 0;

When a fixed PUCCH resource pool is configured for the NP-PTM bearer, each PUCCH in the PUCCH resource pool has a fixed resource index;

when a dynamic PUCCH resource pool is configured for the NP-PTM bearer, designating resource subscripts of M PUCCHs through PDCCHs each time the MAC layer schedules the NP-PTM bearer, specifically, giving a resource subscript of a first PUCCH in the PUCCH resource pool by a PUCCH resource indication field in a DCI format on the PDCCHs, and allocating continuous M resource subscripts to M PUCCHs in the PUCCH resource pool from the resource subscript. The DCI format has the same PUCCH resource indication domain on the PDCCH in each PDCCH occasion;

and transmitting the NP-PTM bearer by using the PDCCH resource and the PDSCH resource which are allocated for the NP-PTM bearer.

In an exemplary manner, the NP-PTM bearer is transmitted using the PDCCH resources and the PDSCH resources allocated for the NP-PTM bearer, comprising:

when the MBS is a broadcast service, b2=b, the MAC layer uses allocated PDCCH resources to transmit PDCCH in the B-th PDCCH in each group of PDCCH occasions, and uses beam B when transmitting the PDCCH, and the cyclic redundancy check CRC of the PDCCH is scrambled with G-RNTI; transmitting a PDSCH by adopting an allocated PDSCH resource at a b-th PDSCH occasion in each group of PDSCH occasions, adopting a wave beam b when transmitting the PDSCH, adopting a G-RNTI when scrambling bits by the PDSCH, and carrying the TB on the PDSCH; b=1, … …, B;

When the MBS is a multicast service, or when the MBS is a broadcast service and UEs receiving the PTM bearer are in an RRC connection state, b2=b, for a Beam coverage area B1 (i) for transmitting the PTM bearer, the MAC layer uses allocated PDCCH resources for a B1 (i) th PDCCH occasion in each group of PDCCH occasions to transmit a PDCCH, uses Beam (i) for transmitting the PDCCH, wherein CRC of the PDCCH is scrambled with a G-RNTI, uses allocated PDSCH resources for a B1 (i) th PDSCH occasion in each group of PDSCH occasions to transmit a PDSCH, uses Beam (i) for transmitting the PDSCH, and uses G-RNTI for bit scrambling; through the above processing, when B1< B, PDSCH need not be transmitted in the remaining PDCCH/PDSCH occasions in each group of PDCCH/PDSCH occasions; i=1, … …, B1;

when the MBS is a multicast service, or when the MBS is a broadcast service and UEs receiving the PTM bearer are in an RRC connection state, b2=b1, transmitting PDCCH/PDSCH by using allocated PDCCH/PDSCH resources in the ith PDCCH/PDSCH occasion in each group of PDCCH/PDSCH occasions, using Beam (i) when transmitting the PDCCH/PDSCH, scrambling CRC of the PDCCH with G-RNTI, carrying the TB on the PDSCH, and using G-RNTI when bit scrambling; and when B1 is not equal to B or the value of B1 is changed, notifying the beam coverage area of the PTM bearing to the UE through a DCI format on a MAC CE or a PDCCH.

In an exemplary manner, for each of the P-PTM bearer and the NP-PTM bearer of the PTM bearer, the gNB summarizes NACK information of the TBs of the P-PTM/NP-PTM bearer fed back by the UE, retransmits the TBs of the P-PTM/NP-PTM bearer, including:

the gNB monitors each PUCCH in a PUCCH resource pool configured for the bearing in each PUCCH occasion in each group of PUCCH occasions configured for the P-PTM/NP-PTM bearing;

and when the gNB determines that the TB is not required to be retransmitted according to the monitoring result, the gNB stops subsequent processing. Otherwise, the gNB determines that each beam coverage area of the TB needs to be retransmitted, when M >1, in each beam coverage area of the TB needs to be retransmitted, the gNB further determines each code group which needs to be retransmitted in the beam coverage area, and b3 represents the subscript of any beam coverage area which needs to be retransmitted;

when m=1, for each beam coverage area b3 in which the TB needs to be retransmitted, the gNB retransmits the TB using the HARQ process used when the TB was initially transmitted in the beam coverage area; when M >1, for each beam coverage area b3 where the TB needs to be retransmitted, the gNB adopts an HARQ process adopted when the TB is initially transmitted in the beam coverage area, and retransmits each code group of the TB that needs to be retransmitted;

The MAC layer retransmits the TBs in each beam coverage area b3 in a dynamic scheduling manner.

In an exemplary manner, the MAC layer retransmits the TB in a dynamic scheduling manner, including:

allocating PDCCH resources, PDSCH resources and PUCCH resources for the TB, wherein the PDCCH resources comprise B2.N 5 PDCCH opportunities, the PDSCH resources comprise B2.N 5 PDSCH opportunities, the PUCCH resources comprise B2.N 6 PUCCH opportunities, N5 is the repeated transmission times of the PDCCH/PDSCH, and N6 is the repeated transmission times of the PUCCH;

when b2=b, the B-th PDCCH/PDSCH occasion in each set of PDCCH/PDSCH occasions is used for transmitting PDCCH/PDSCH in the beam coverage area B, for each beam coverage area B3, the MAC layer allocates resources for PDCCH/PDSCH in the B3-th PDCCH/PDSCH occasion in each set of PDCCH/PDSCH occasions, PDSCH resources allocated in each PDSCH occasion are used for retransmitting the TB when m=1, and are used for retransmitting each code group of the TB that needs retransmission when M > 1; transmitting PDCCH/PDSCH by using allocated PDCCH/PDSCH resources in the b3 rd PDCCH/PDSCH occasion in each group of PDCCH/PDSCH occasions, adopting a wave beam b3 when transmitting the PDCCH/PDSCH, scrambling the CRC of the PDCCH by using SPS G-RNTI when the TB is a TB carried by P-PTM, adopting the SPS G-RNTI when the PDSCH is bit scrambled, scrambling the CRC of the PDCCH by using G-RNTI when the TB is a TB carried by NP-PTM, adopting G-RNTI when the PDSCH is bit scrambled, carrying the TB on the PDSCH when the TB needs to be retransmitted in a wave beam coverage area b3, and carrying each code group of the TB needs to be retransmitted when at least one code group of the TB needs to be retransmitted in the wave beam coverage area b 3;

When b2=b1, the P-th PDCCH/PDSCH occasion in each set of PDCCH/PDSCH occasions is used for transmitting PDCCH/PDSCH in beam coverage B1 (P), p=1, …, B1, and for each beam coverage B3, if b3=b1 (P), the MAC layer allocates resources to PDCCH/PDSCH in the P-th PDCCH/PDSCH occasion in each set of PDCCH/PDSCH occasions, the PDSCH resources allocated in each PDSCH occasion are used for retransmitting the TB when m=1, and each code group requiring retransmission of the TB when M > 1; and transmitting PDCCH/PDSCH by adopting allocated PDCCH/PDSCH resources in the P-th PDCCH/PDSCH occasion in each group of PDCCH/PDSCH occasions, adopting a beam (P) when transmitting the PDCCH/PDSCH, scrambling the CRC of the PDCCH by adopting SPS G-RNTI when the TB is a TB borne by P-PTM, scrambling the CRC of the PDCCH by adopting the SPS G-RNTI when the TB is a TB borne by NP-PTM, adopting the G-RNTI when the PDSCH is subjected to bit scrambling, carrying the TB on the PDSCH when the TB needs to be retransmitted in a beam coverage area b3, and carrying each code group of the TB which needs to be retransmitted on the PDSCH when at least one code group of the TB needs to be retransmitted in the beam coverage area b 3.

In an exemplary manner, when b2=b, the B-th PUCCH occasion in each set of PUCCH occasions is used for the UE located in the beam coverage area B to feed back ACK/NACK information of the TB, and for each beam coverage area B3, the MAC layer allocates resources to the PUCCH in the B3-th PUCCH occasion in each set of PUCCH occasions, and allocates the same PUCCH resources to PUCCH occasions in different sets;

When b2=b1, the P-th PUCCH occasion in each group of PUCCH occasions is used for the UE located in the beam coverage area B1 (P) to feed back ACK/NACK information of the TB, and when b3=b1 (P) is used for each beam coverage area B3, the MAC layer allocates resources to the PUCCH in the P-th PUCCH occasion in each group of PUCCH occasions, and allocates the same PUCCH resources to PUCCH occasions in different groups.

The second aspect of the present invention provides a feedback and retransmission method for ACK/NACK information of MBS, applied to a UE, the method comprising:

the UE receives each P-PTM bearer and NP-PTM bearer of a point-to-multipoint PTM bearer of a multicast broadcast service MBS sent by a gNB;

when the UE decodes the transport block TB carried by the P-PTM/NP-PTM in error, the UE generates NACK information of the TB and feeds back the NACK information of the TB through a physical uplink control channel PUCCH corresponding to the P-PTM/NP-PTM.

In an exemplary manner, when the UE decodes an error in a transport block TB carried by the P-PTM/NP-PTM, the UE generates NACK information of the TB, and feeds back the NACK information of the TB through a physical uplink control channel PUCCH corresponding to the P-PTM/NP-PTM carrier, including:

when the UE decodes the TB carried by the P-PTM/NP-PTM, determining a PUCCH to be sent from a PUCCH resource pool according to the number M of PUCCHs included in the PUCCH resource pool allocated to the P-PTM/NP-PTM carried and a preset criterion for feeding back ACK/NACK information of the TB carried by the P-PTM/NP-PTM, wherein the PUCCH is used for feeding back the ACK/NACK information of the TB to the gNB, and M is greater than or equal to 1;

And the UE determines the PUCCH occasion for transmitting the PUCCH and transmits the PUCCH in the corresponding PUCCH occasion.

In an exemplary manner, when the UE decodes the TB of the P-PTM/NP-PTM bearer in error, determining, from a PUCCH resource pool, a PUCCH to be transmitted according to a number M of PUCCHs included in the PUCCH resource pool allocated to the P-PTM/NP-PTM bearer and a preset criterion for feeding back ACK/NACK information of the TB of the P-PTM/NP-PTM bearer, where the PUCCH is used to feed back the ACK/NACK information of the TB to the gNB, including:

when m=1, when the UE decodes the TB of the P-PTM/NP-PTM bearer in error, the UE determines to transmit a unique PUCCH in the PUCCH resource pool.

M＝2 ^C -1, c is the maximum number of code groups supported by one TB;

and the UE divides the TB borne by the P-PTM/NP-PTM into C code groups, and feeds back ACK/NACK information of each code group when the UE decodes the TB in error.

In an exemplary manner, the UE divides TBs of the P-PTM/NP-PTM bearer into C code groups, and when the UE decodes the TBs in error, the UE feeds back ACK/NACK information of each code group, including:

when the UE decodes the TB carried by the P-PTM/NP-PTM, dividing the TB into C code groups by the UE, generating a bit sequence with the length of C bits, wherein the C bit in the bit sequence corresponds to the C code group according to the left-to-right sequence, and when the UE decodes the C code group correctly, the value of the C bit is 1; otherwise, the value of the c-th bit is 0; c=1, …, C;

and the UE determines a decimal value V corresponding to the bit sequence, selects a PUCCH with a subscript V from M PUCCHs contained in the PUCCH resource pool according to the decimal value V, and sends the PUCCH.

At m=3, when the UE decodes the TB carried by the P-PTM/NP-PTM, the UE divides the TB into c=2 blocks, when the UE decodes the TB for both blocks, the UE transmits a PUCCH with a subscript of 0 in the PUCCH resource pool, when the UE decodes only the first block, the UE transmits a PUCCH with a subscript of 2 in the PUCCH resource pool, and when the UE decodes only the second block, the UE transmits a PUCCH with a subscript of 1 in the PUCCH resource pool.

at m=7, when the UE decodes the TB carried by the P-PTM/NP-PTM, the UE divides the TB into c=4 code groups, and when the UE decodes only the C-th code group, the UE transmits PUCCH with subscript C in the PUCCH resource pool, c=1, 2,3,4; when the UE decodes the first two code groups in error, the UE transmits a PUCCH with the subscript of 5 in the PUCCH resource pool; when the UE decodes the last two code groups in error, the UE transmits a PUCCH with the subscript of 6 in the PUCCH resource pool; when the UE decodes errors on all four code groups, the UE transmits a PUCCH with the subscript of 0 in the PUCCH resource pool.

A third aspect of the invention provides a gNB comprising functional modules that perform the first aspect of the invention or any of the example implementations of the first aspect.

A fourth aspect of the invention provides a UE comprising functional modules to perform the second aspect or any of the example implementations of the second aspect of the invention.

A fifth aspect of the invention provides a gNB comprising a processor, a memory for storing instructions, and a transceiver for communicating with other devices, the processor for executing instructions stored in the memory to cause the base station to perform a method according to the first aspect of the invention or any of the example implementations of the first aspect.

A sixth aspect of the invention provides a UE comprising a processor, a memory for storing instructions, and a transceiver for communicating with other devices, the processor for executing instructions stored in the memory to cause the UE to perform a method according to the second aspect or any of the example implementations of the second aspect of the invention.

A seventh aspect of the invention provides a computer readable storage medium storing instructions that, when executed, cause a computer to perform a method according to the first aspect of the invention or any of the example implementations of the first aspect.

An eighth aspect of the invention provides a computer readable storage medium storing instructions that, when executed, cause a computer to perform a method according to the second aspect of the invention or any of the example implementations of the second aspect.

When the gNB determines that the MBS is transmitted through the MPT bearing, the method and the device for feeding back and retransmitting the ACK/NACK information of the MBS are provided, the gNB configures the PTM bearing of the MBS, so that the gNB can transmit the TB of the MPT bearing through a plurality of HARQ processes in parallel, a PUCCH resource pool is configured for the PTM bearing, the UE receiving the PTM bearing feeds back the ACK/NACK information of the TB of the PTM bearing through the PUCCH in the PUCCH resource pool, and the gNB retransmits the TB with failed transmission or retransmits the code group with failed transmission in the TB according to the ACK/NACK information of the TB of the PTM bearing. The method enables the MBS based on MPT bearing transmission to retransmit the TB with failed transmission, so that the MBS meets QoS requirements.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.

FIG. 1 is a schematic diagram of MBS architecture in NR system;

fig. 2 is a signaling flow chart of a feedback and retransmission method of ACK/NACK information of MBS according to a first embodiment of the present invention;

fig. 3 is a flowchart of a feedback and retransmission method of ACK/NACK information of MBS according to a second embodiment of the present invention;

fig. 4 is a flowchart of a feedback and retransmission method of ACK/NACK information of MBS according to the third embodiment of the present invention;

fig. 5 is a flowchart of a feedback and retransmission method of ACK/NACK information of MBS according to a fourth embodiment of the present invention;

fig. 6 is a flowchart of a feedback and retransmission method of ACK/NACK information of MBS according to a fifth embodiment of the present invention;

fig. 7 is a schematic structural diagram of a gNB according to a sixth embodiment of the present invention;

fig. 8 is a schematic structural diagram of a UE according to a seventh embodiment of the present invention;

fig. 9 is a schematic structural diagram of a gNB according to an eighth embodiment of the present invention.

Specific embodiments of the present invention have been shown by way of the above drawings and will be described in more detail below. The drawings and the written description are not intended to limit the scope of the inventive concepts in any way, but rather to illustrate the inventive concepts to those skilled in the art by reference to the specific embodiments.

Detailed Description

Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated.

In order to solve the problems in the prior art, the present invention provides a feedback and retransmission method for ACK/NACK information of an MBS, for an MBS transmitted with a PTM bearer, a gNB allocates H hybrid automatic repeat request (Hybrid Automatic Repeat Request, abbreviated as HARQ) processes to the PTM bearer, for transmitting TBs of the PTM bearer in parallel, configures a physical uplink control channel (Physical Uplink Control Channel, abbreviated as PUCCH) resource pool for the PTM bearer, a UE receiving the PTM bearer feeds back ACK/NACK information of TBs of the PTM bearer through the PUCCH in the PUCCH resource pool, and the gNB retransmits TBs with respect to a TB with transmission failure or retransmits with respect to a code group with transmission failure in the TB according to the ACK/NACK information of the TBs with the PTM bearer.

Fig. 2 is a signaling flow chart of an ACK/NACK information feedback and retransmission method of an MBS according to an embodiment of the present invention, where the method of the present embodiment is performed by a gNB, as shown in fig. 2, and the method of the present embodiment includes the following steps:

S101, for any MBS, when the gNB determines that the MBS is transmitted through a PTM bearer, configuring a Group radio network temporary identifier (Group-Radio Network Tempory Identity, G-RNTI for short) and a semi-static (Semi persistent state, SPS for short) G-RNTI for the MBS, determining a BWP for transmitting the PTM bearer of the MBS, and configuring an SDAP entity, a PDCP entity and an RLC entity for the PTM bearer of the MBS.

Specifically, the gNB configures 1 service data adaptation protocol (Service Data Adaption Protocol, abbreviated as SDAP) entity for the PTM Bearer of the MBS, where the SDAP entity maps QoS flows (QoS flows) included in the MBS onto K radio bearers (Rado bearers, abbreviated as RBs). The gNB configures a packet data convergence protocol (Packet Data Convergence Protocol, abbreviated PDCP) entity for each RB generated, and the SDAP entity is connected to the kth PDCP entity through the kth RB, k=1, … …, K. The gNB configures K radio link control (Radio Link Control, RLC for short) entities for PTM bearer of MBS, the kth RLC entity is connected with the kth PDCP entity through RLC channel upwards, and is connected with media access control (Media Access Control, MAC for short) layer of cell through kth Single-cell multicast service channel (Single-Cell Multicast Service Channel, SC-MTCH for short) downwards. The SC-MTCH is a newly added service channel and is special for PTM bearing.

The SDAP entity transmits the generated SDAP protocol data unit (Protocol Data Unit, abbreviated PDU) of the kth RB to the kth PDCP entity, the kth PDCP entity transmits the generated PDCP PDU to the kth RLC entity through an RLC channel, and the kth RLC entity transmits the generated RLC PDU to the MAC layer through the kth SC-MTCH.

Each RLC entity adopts an unacknowledged Mode (Unacknowledged Mode, UM) or a Transparent Mode (TM). Typically, the RLC entity of each RB adopts UM mode.

S102, gNB divides K RBs contained in the PTM bearer into: K1P-RBs and/or K-K1 NP-RBs, wherein each P-RB has the characteristics of periodic transmission and fixed data quantity transmitted each time. And dividing the PTM bearer into K1P-PTM bearers and/or 1 NP-PTM bearer according to the type of the RB, wherein each P-RB has a unique P-PTM bearer for transmitting the RB, and 1 NP-PTM bearer is used for transmitting all NP-RBs.

The number of RBs mapped by different MBS is different, that is, the value of K is different, in this embodiment, K RBs included in the PTM bearer of the MBS are divided into two classes: a first class of RBs and a second class of RBs. The first type of RB is represented by P-RB, the second type of RB is represented by NP-RB, and the numbers of the two types of RBs are represented by K1 and K-K1 respectively.

And the value of K1 is greater than or equal to 0 and less than or equal to K, and when K1=K, only P-RB and NP-RB are included in the K RBs. When k1=0, only NP-RBs are included in the K RBs, and P-RBs are not included. When K1 is greater than 0 and less than K, P-RB and NP-RB are included in the K RBs at the same time.

S103, when the MBS is multicast service or the MBS is broadcast service, but the UE receiving the PTM bearing of the MBS is in an RRC connection state, the MAC layer determines each beam coverage area for transmitting the PTM bearing according to the position of the UE receiving the RRC connection state of the PTM bearing, and determines a beam adopted when the PTM bearing is transmitted in each beam coverage area for transmitting the PTM bearing.

The number of beams used when transmitting a synchronization signal/physical broadcast channel BLOCK (SS/PBCH BLOCK) is denoted by B, the B-th Beam used when transmitting an SS/PBCH BLOCK is denoted by Beam B, b=1, …, B, the cell includes B Beam coverage areas, subscripts of the Beam coverage areas are from 1 to B, beam coverage area B is the coverage area of the B-th Beam, the number of Beam coverage areas transmitting the PTM bearer is denoted by B1, the subscript of the i-th Beam coverage area in the B1 Beam coverage area transmitting the PTM bearer is denoted by B1 (i), the Beam used when transmitting the PTM bearer in Beam coverage area B1 (i), i=1, …, B1.

Specifically, the MAC layer determines, according to the location of the RRC-connected UE receiving the PTM bearer, each Beam coverage area b1 (i) that needs to send the PTM bearer, and the method for determining, by using each Beam coverage area b1 (i), the Beam (i) that is used when sending the PTM bearer is specifically as follows:

the MAC layer determines the beam coverage area where each RRC connected UE receiving the PTM bearer is located. For each beam coverage area, when at least one UE is located in the beam coverage area, a subscript of the beam coverage area is recorded. And transmitting the PTM bearer in each recorded beam coverage area. The number of beam coverage areas recorded is denoted B1. The subscript of the ith Beam coverage area in the recorded B1 Beam coverage areas is denoted by B1 (i), and when there is only one UE in the Beam coverage areas B1 (i), the Beam (i) adopted when the P-PTM bearer is transmitted in the Beam coverage area is the dedicated Beam of the UE. When there is more than one UE in the Beam coverage area b1 (i), the Beam (i) used when transmitting the PTM bearer in the Beam coverage area is the Beam b1 (i). However, if the UEs within the Beam coverage area are located within a narrow direction within the Beam coverage area, a narrow Beam may be formed by dedicated beams of all UEs within the Beam coverage area, and the Beam (i) used when the PTM is transmitted within the Beam coverage area is the formed narrow Beam.

S104, each P-PTM bearer and NP-PTM bearer of the PTM bearer are sent on BWP sending the PTM bearer.

S105, the UE receives each P-PTM bearer and NP-PTM bearer of the PTM bearer, when the UE decodes the TB of the P-PTM/NP-PTM bearer in error, the UE generates NACK information of the TB, and feeds back the NACK information of the TB through a PUCCH corresponding to the P-PTM/NP-PTM bearer.

S106, for each P-PTM bearer and NP-PTM bearer of the PTM bearer, the gNB gathers NACK information of the TB of the P-PTM/NP-PTM bearer fed back by the UE, and retransmits the TB of the P-PTM/NP-PTM bearer.

On the basis of the first embodiment, a specific implementation method of sending each P-PTM bearer of the PTM bearer on the BWP sending the PTM bearer in step S104 in the embodiment shown in fig. 2 is described in the second embodiment of the present invention, and as shown in fig. 3, the embodiment of the present invention includes the following steps:

s201, gNB configures semi-static resources for P-PTM bearing for periodically sending the P-PTM bearing, wherein the semi-static resources comprise semi-static PDSCH resources and semi-static PUCCH resources.

The configuration information of the semi-static resource may include the following:

period T (one)

(II) semi-static PDSCH resource configuration information

The semi-static PDSCH resource configuration information includes four information:

(1) Initial radio frame OFFSET SFN_OFFSET and initial time slot OFFSET TS_OFFSET

(2) PDSCH repetition number N1

(3) Number of beams B2 used when PDSCH is transmitted

(4) Frequency resources occupied by PDSCH

(III) semi-static PUCCH resource configuration information

The semi-static PUCCH resource configuration information comprises the following four kinds of information

(1) Timing difference d

(2) PUCCH repetition number N2

(3) And a PUCCH resource pool, wherein the resource pool comprises M PUCCHs, each PUCCH is identified by a resource index, and each PUCCH adopts a format 0.

(4) The time-frequency resources occupied by the PUCCH include a start symbol index, a number of symbols, a physical resource block (Physical Resource Block, abbreviated PRB) offset, and a Cyclic Shift (CS) index set.

The resource pool consists of M PUCCHs, each PUCCH is identified by a unique PUCCH resource index, and the UE receiving the P-PTM load shares the PUCCH in the resource pool. Each PUCCH in the PUCCH resource pool employs format 0.

According to the configuration information of the semi-static resources, the MAC layer of the gNB allocates consecutive B2 x N1 PDSCH occasions (each occasion corresponds to a time slot) to the PDSCH in a period with each length of T radio frames, starts from a time slot indicated by a starting time slot OFFSET ts_offset in a radio frame indicated by a starting radio frame OFFSET sfn_offset, the frequency resources allocated to the PDSCH in each occasion are the same, the resources are given by "frequency resources occupied by the PDSCH" in the configuration information, the PDSCH is transmitted by using the allocated frequency resources in each PDSCH occasion in each period, each PDSCH carries the same TB, and the TB is composed of MAC PDUs carried by the P-PTM.

In the same period, B2×N2 PUCCH opportunities (each opportunity corresponds to a time slot) are allocated to the PUCCH, the subscripts of the PUCCH opportunities are from 0 to (B2×N2-1), the time-frequency resources allocated to the PUCCH in each opportunity are the same, and the resources are given by the time-frequency resources occupied by the PUCCH in the configuration information. In each PUCCH occasion, the starting symbol index of the sending PUCCH and the continuous symbol number occupied by the PUCCH are respectively determined by the starting symbol index and the symbol number, the starting PRB of the sending PUCCH is determined by the PRB bias, and the index of CS adopted by the PUCCH on each PRB of the sending PUCCH is determined by the CS index set. The PUCCH for indicating NACK information of the TB carried by the P-PTM in each PUCCH occasion is given by a "PUCCH resource pool".

The timing difference between PUCCH occasion subscripted 0 and PDSCH occasion subscripted B2 x (N1-1) is d slots, namely: if PDSCH timing with subscript B2 x (N1-1) is in slot t, PUCCH timing with subscript 0 is in slot (t+d).

S202, in each period corresponding to semi-static PDSCH resources, the MAC layer divides B2N 1 PDSCH opportunities allocated to the P-PTM bearer into N1 groups, and each B2 opportunities form a group from the PDSCH opportunity with the subscript of 0; the MAC layer groups the B2 x N2 PUCCH occasions allocated to the P-PTM bearer into N2 groups, and groups every B2 occasions from a PUCCH occasion with subscript 0.

S203, in each period corresponding to the semi-static PDSCH resource, the MAC layer generates a TB by the MAC PDU carried by the P-PTM, and determines the HARQ process adopted by the TB.

H HARQ processes are allocated to MBS in 3GPP protocol and are used for parallel transmission of the P-PTM bearer. When the TB carried by the P-PTM is sent, H HARQ processes are adopted in a circulating way.

In each period corresponding to the semi-static PDSCH resources, the frame number SFN of the starting radio frame satisfies the following equation:

(SFN)MOD(T)＝0。

(SFN)MOD(T)＝SFN_OFFSET。

ID＝INT(SFN/T)MOD H。

in the above formula, MOD represents modulo two integers, INT (X) represents rounding a real number X, sfn_offset represents a starting radio frame OFFSET, T represents a period of PDSCH resources, and H represents the number of HARQ processes.

After step S203, the P-PTM bearer may be sent in any of the ways of steps S204-S206.

S204, when the MBS is a broadcast service, b2=b, in each period corresponding to the semi-static PDSCH resource, the MAC layer uses the allocated PDSCH resource to transmit the PDSCH at the B-th PDSCH occasion in each group of PDSCH occasions, and uses the beam B when transmitting the PDSCH, where the PDSCH carries the TB. The PDSCH uses SPS G-RNTI, b=1, …, B2 when bit scrambling.

Specifically, the b-th PDSCH occasion in each set of PDSCH occasions is used for transmitting PDSCH in the beam coverage area b, the PDSCH carries the TB, and the PDSCH is transmitted by using the beam b. The TB may be repeatedly transmitted N1 times in each beam coverage area through N1 sets of PDSCH occasions.

S205, when the MBS is a multicast service, or when the MBS is a broadcast service and the UEs receiving the PTM bearer are in RRC connection, b2=b, in each period corresponding to the semi-static PDSCH resources, for transmitting the Beam coverage area B1 (i) of the PTM bearer, the MAC layer uses the allocated PDSCH resources for the B1 (i) th PDSCH occasion in each set of PDSCH occasions to transmit the PDSCH, uses the Beam (i) when transmitting the PDSCH, carries the TB on the PDSCH, uses the SPS G-RNTI when bit scrambling, i=1, …, B1, and after the above processing, when B1< B, does not need to transmit the PDSCH in the remaining PDSCH occasions in each set of PDSCH occasions.

Specifically, the b-th PDSCH occasion in each set of PDSCH occasions is used for transmitting PDSCH in beam coverage area b, and the PDSCH occasions allocated to the P-PTM bearer support repeated transmission of the TB N1 times in each beam coverage area.

And when the number B1< B of the beam coverage areas carried by the P-PTM is sent, sending PDSCH in B1 PDSCH occasions in each group of PDSCH occasions, wherein the B1 PDSCH occasions are in one-to-one correspondence with the B1 beam coverage areas carried by the P-PTM.

S206, when the MBS is a multicast service, or when the MBS is a broadcast service and the UE receiving the PTM bearer is in an RRC connection state, in each period corresponding to the semi-static PDSCH resources, the MAC layer uses the allocated PDSCH resources in the ith PDSCH occasion in each group of PDSCH occasions to transmit the PDSCH, uses Beam (i) when transmitting the PDSCH, and carries the TB on the PDSCH, and uses SPS G-RNTI when bit scrambling, and when B1< B, or when the value of B1 changes, notifies the UE of the Beam coverage area of the PTM bearer through MAC CE or through PDCCH uplink/downlink control information (Downlink Control information, DCI for short) format.

Specifically, the ith PDSCH occasion in each set of PDSCH occasions is used for transmitting the TB carried by the P-PTM in the beam coverage area b1 (i), and the TB can be repeatedly transmitted N1 times in the beam coverage area b1 (i) through the N1 sets of PDSCH occasions.

Specifically, the MAC CE is sent through the P-PTM bearer in a dynamic scheduling mode. The MAC CE carries a "beam indication field". The field is composed of B bits, the B bits are numbered from 1 in order from left to right, and the a bit is 1 to indicate that the P-PTM bearer is sent in the beam coverage area a; bit a is 0, which means that the P-PTM bearer is not transmitted in beam coverage area a, a=1, …, B, and the value of B1 bits in the beam indication field is 1.

The UE may also be notified of the beam coverage area for transmitting the PTM bearer via a DCI format on PDCCH. Specifically, a "beam indication field" is set in the DCI format. The setting method of the domain is the same as above. The method of transmitting the PDCCH including the DCI format of the "beam indication field" is the same as the method of transmitting the PDCCH that activates/deactivates the semi-static PDSCH resource carried by the P-PTM. The method for transmitting PDCCH for activating/deactivating the semi-static PDSCH resource carried by P-PTM is not the present invention and will not be described in detail.

On the basis of the first embodiment, a specific implementation manner of sending the NP-PTM bearer of the PTM bearer on the BWP sending the PTM bearer in step S104 in the embodiment shown in fig. 2 in the third embodiment of the present invention is described, and as shown in fig. 4, the embodiment of the present invention includes the following steps:

s301, when the MAC layer schedules the NP-PTM bearer, PDCCH resources, PDSCH resources and PUCCH resources are allocated for the NP-PTM bearer, and a TB is formed by MAC PDU carried by the NP-PTM according to the allocated PDSCH resources. The NP-PTM bearer is used to send all NP-RBs. The MAC PDU carried by the NP-PTM is multiplexed by the MAC SDUs on each NP-RB. The MAC layer selects an idle HARQ process for the TB, through which the TB is transmitted.

The detailed description of this step is as follows:

every time the MAC layer schedules the NP-PTM bearer, the PDCCH resources allocated for the NP-PTM bearer are composed of B2×n3 PDCCH occasions, and the same Control-resource set (CCE) resources or different CCE resources are allocated for the PDCCH in each PDCCH occasion. The B2 x N3 PDCCH occasions are divided into N3 groups, each group comprising B2 PDCCH occasions. And N3 is the repeated transmission times of the PDCCH.

Every time the MAC layer schedules the NP-PTM bearer, the PDSCH resources allocated for the NP-PTM bearer are composed of B2N 3 PDSCH opportunities, and the same frequency resources or different frequency resources are allocated for the PDSCH at each PDSCH opportunity. The B2 x N3 PDSCH occasions are divided into N3 groups, each group comprising B2 PDSCH occasions. N3 is the number of PDSCH repeated transmissions.

The DCI format on the PDCCH transmitted in the ith PDCCH occasion is dynamic scheduling information of the PDSCH transmitted in the ith PDSCH occasion, the timing difference between the PDCCH and the corresponding PDSCH is fixed to d1, d1 is specified by the DCI format on the PDCCH, i=0, …, and B2×n3-1. The DCI format on each PDCCH indicates the same d1.

When the content of the DCI format on the PDCCH transmitted in each PDCCH occasion is the same, the number of times of repeated transmission of the PDCCH may be different from the number of times of repeated transmission of the PDSCH.

Every time the MAC layer schedules the NP-PTM bearer, the PUCCH resources allocated for the NP-PTM bearer are composed of B2×n4 PUCCH occasions, the B2×n4 PUCCH occasions are divided into N4 groups, each group includes B2 consecutive PUCCH occasions, N4 is the number of PUCCH repeated transmissions, the same time-frequency resource is allocated for the PUCCH in each PUCCH occasion, the time-frequency resource is determined by "starting symbol index 1", "symbol number 1", "PRB offset 1", and "CS index set 1", the PUCCH transmitted on the allocated time-frequency resource in each PUCCH occasion is given by "PUCCH resource pool", the PUCCH resource pool is composed of M PUCCHs, and each PUCCH adopts format 0.

Specifically, in each PUCCH occasion, the starting symbol index of the transmit PUCCH and the number of consecutive symbols occupied by the PUCCH are determined by "starting symbol index 1" and "symbol number 1", respectively, the starting PRB of the transmit PUCCH is determined by "PRB offset 1", and the index of CS employed by the PUCCH on each PRB of the transmit PUCCH is determined by "CS index set 1".

When a fixed PUCCH resource pool is configured for the NP-PTM bearer, each PUCCH in the PUCCH resource pool has a fixed resource index.

And when the dynamic PUCCH resource pool is configured for the NP-PTM bearer, designating resource subscripts of M PUCCHs through PDCCH each time the MAC layer schedules the NP-PTM bearer. Specifically, a "PUCCH resource indication" field in the DCI format on the PDCCH gives a resource index of a first PUCCH in the PUCCH resource pool, and consecutive M resource indexes are allocated to M PUCCHs in the PUCCH resource pool from the resource index. The DCI formats have the same "PUCCH resource indication" field on PDCCH within each PDCCH occasion.

The timing difference d2 between the first PDSCH occasion in the first PUCCH occasion and the first PDSCH occasion in the N3 rd group of PDSCH occasions is indicated by the DCI format on the PDCCH in the first PDCCH occasion in the last group of PDCCH occasions. The DCI format indicates the same d2 on the PDCCH transmitted in each PDCCH occasion.

After step S301, the NP-PTM bearer is sent in any of steps S302-S304.

S302, when MBS is a broadcast service, B2=B, the MAC layer adopts an allocated PDCCH resource to transmit PDCCH at a B-th PDCCH occasion in each group of PDCCH occasions, and adopts a wave beam B when transmitting the PDCCH, and cyclic redundancy check (Cyclic Redundancy Check, CRC for short) of the PDCCH is scrambled by G-RNTI; transmitting a PDSCH by adopting an allocated PDSCH resource at a b-th PDSCH occasion in each group of PDSCH occasions, adopting a wave beam b when transmitting the PDSCH, adopting a G-RNTI when scrambling bits by the PDSCH, and carrying the TB on the PDSCH; b=1, … …, B.

S303, when MBS is multicast service or when MBS is broadcast service and UE receiving PTM load is in RRC connection state, B2=B, MAC layer adopts allocated PDCCH resource to transmit PDCCH in the B1 (i) PDCCH time in each group of PDCCH time, adopts wave Beam (i) when transmitting PDCCH, and CRC of PDCCH is scrambled by G-RNTI; b1 (i) th PDSCH occasion in each group of PDSCH occasions adopts allocated PDSCH resources to transmit PDSCH, beam (i) is adopted when the PDSCH is transmitted, the PDSCH bears the TB, and G-RNTI is adopted when the PDSCH is scrambled by bits; through the above processing, when B1< B, PDSCH need not be transmitted in the remaining PDCCH/PDSCH occasions in each group of PDCCH/PDSCH occasions; i=1, … …, B1.

S304, when MBS is multicast service or when MBS is broadcast service and UE receiving PTM load is in RRC connection state, B2=B1, the allocated PDCCH/PDSCH resource is adopted in the ith PDCCH/PDSCH time in each group of PDCCH/PDSCH time to transmit PDCCH/PDSCH, beam (i) is adopted when transmitting the PDCCH/PDSCH, CRC of the PDCCH is scrambled by G-RNTI, the TB is borne on the PDSCH, and G-RNTI is adopted when bit scrambling is carried out on the PDSCH; and when B1 is not equal to B or the value of B1 is changed, notifying the beam coverage area of the PTM bearing to the UE through a DCI format on a MAC CE or a PDCCH.

Preferably, the MAC CE is sent through the NP-PTM bearer in a dynamic scheduling mode. The MAC CE includes the same contents as the above step S206.

Preferably, the UE may also be notified of the beam coverage area of the PTM bearer by using a DCI format on the PDCCH, where the DCI format includes the same contents as in step S206. When the DCI format carries information for transmitting the beam coverage area carried by the PTM, the corresponding PDCCH does not have the corresponding PDSCH.

On the basis of the first to third embodiments, the fourth embodiment of the present invention describes in detail step S105 in the embodiment shown in fig. 2, and as shown in fig. 5, the embodiment of the present invention includes the following steps:

S401, when the UE decodes the TB carried by the P-PTM/NP-PTM, determining a PUCCH to be transmitted from a PUCCH resource pool according to the number M of PUCCHs included in the PUCCH resource pool allocated to the P-PTM/NP-PTM and a preset criterion for feeding back ACK/NACK information of the TB carried by the P-PTM/NP-PTM, wherein the PUCCH is used for feeding back the ACK/NACK information of the TB to the gNB.

The processing of the step is specifically as follows:

scene one, m=1.

In scenario one, the PUCCH resource pool contains only 1 PUCCH, and the UE can only feed back NACK information of TBs carried by P-PTM/NP-PTM to the gNB through the PUCCH.

Specifically, when m=1, when the UE decodes the TB of the P-PTM/NP-PTM bearer in error, the UE determines to transmit the unique PUCCH in the PUCCH resource pool.

Scene two, m=2 ^C -1, c is the maximum number of code groups supported by one TB.

In a second scenario, the UE divides the TBs carried by the P-PTM/NP-PTM into C blocks, and when the UE decodes the TBs in error, the UE feeds back ACK/NACK information of each block.

Specifically, when the UE decodes the TB carried by the P-PTM/NP-PTM, the UE divides the TB into C code groups, generates a bit sequence with the length of C bits, and the C bit in the bit sequence corresponds to the C code group according to the left-to-right order, and when the UE decodes the C code group correctly, the value of the C bit is 1; otherwise, the value of the c-th bit is 0; c=1, …, C.

The UE determines a decimal value V corresponding to the bit sequence, selects a PUCCH with a subscript V from M PUCCHs contained in a PUCCH resource pool according to the value, and sends the PUCCH.

When the number C of the code groups is larger, the method for feeding back the ACK/NACK information of each code group occupies more PUCCH resources.

Scene three, m=3.

When m=3, when the UE decodes the TB carried by the P-PTM/NP-PTM, the UE divides the TB into c=2 blocks, when the UE decodes both blocks with errors, the UE transmits PUCCH with index 0 in the PUCCH resource pool, when the UE decodes only the first block with errors, the UE transmits PUCCH with index 2 in the PUCCH resource pool, and when the UE decodes only the second block with errors, the UE transmits PUCCH with index 1 in the PUCCH resource pool.

Scene four, m=7.

When the UE decodes the TB carried by the P-PTM/NP-PTM, the UE divides the TB into C=4 code groups, and when the UE decodes the C code group only, the UE sends a PUCCH with the subscript C in a PUCCH resource pool, wherein c=1, 2,3 and 4; when the UE decodes the first two code groups, the UE transmits a PUCCH with the subscript of 5 in the PUCCH resource pool; when the UE decodes the last two code groups, the UE transmits a PUCCH with the subscript of 6 in the PUCCH resource pool; when the UE decodes an error for all four code groups, the UE transmits PUCCH with index 0 in the PUCCH resource pool.

S402, the UE determines the PUCCH timing for transmitting the PUCCH, and transmits the PUCCH in the corresponding PUCCH timing.

Specifically, when b2=b, for the P-PTM/NP-PTM bearer, the B-th PUCCH occasion in each group of PUCCH occasions is used for the UE located in the beam coverage area B to feed back ACK/NACK information of the TB, and b=1, …, B. And the UE determines the beam coverage area b2 where the UE is positioned, and transmits the PUCCH in the b 2-th PUCCH occasion in each group of PUCCHs. The PUCCH is repeatedly transmitted N2/N4 times in N2/N4 groups of PUCCH opportunities.

Specifically, when b2=b1, the p-th PUCCH occasion in each group of PUCCHs corresponds to a beam coverage area with subscript B (p), and p=1, …, B1 is used for the UE located in beam coverage area B (p) to feed back ACK/NACK information of the TB. The UE determines a beam coverage area B2 where the UE is located, and when B2 is a subscript B1 (j) of a j-th beam coverage area in B1 beam coverage areas for transmitting the P-PTM/NP-PTM bearer, namely: b2 =b1 (j), then the UE transmits the PUCCH at the jth PUCCH occasion in each group of PUCCHs. The PUCCH is repeatedly transmitted N2/N4 times in N2/N4 groups of PUCCH opportunities.

On the basis of the first to fourth embodiments, step S106 in the embodiment shown in fig. 2 is described in detail in the fifth embodiment of the present invention, and as shown in fig. 6, the embodiment of the present invention includes the following steps:

S501, gNB monitors each PUCCH in the PUCCH resource pool configured for the bearing in each PUCCH occasion in each group of PUCCH occasions configured for the P-PTM/NP-PTM bearing.

S502, when the gNB determines that retransmission of the TB is not needed according to the monitoring result, the gNB stops subsequent processing. Otherwise, the gNB determines that each beam coverage area of the TB needs to be retransmitted, and when M >1, in each beam coverage area of the TB needs to be retransmitted, the gNB further determines each code group in the beam coverage area that needs to be retransmitted. Any subscript of the beam coverage area that needs to retransmit the TB is denoted by b 3.

S503, when m=1, for each beam coverage area b3 in which the TB needs to be retransmitted, retransmitting the TB by using the HARQ process used when the TB is initially retransmitted in the beam coverage area by the gNB; when M >1, for each beam coverage area b3 where the TB needs to be retransmitted, the gNB uses the HARQ process used when the TB is initially transmitted in the beam coverage area, and retransmits each code group of the TB that needs to be retransmitted.

S504, the MAC layer retransmits the TB in each beam coverage area B3 in a dynamic scheduling mode, PDCCH resources, PDSCH resources and PUCCH resources are allocated for the TB, the PDCCH resources consist of B2.N 5 PDCCH occasions, the PDSCH resources consist of B2.N 5 PDSCH occasions, and the PUCCH resources consist of B2.N 6 PUCCH occasions. N5 is the number of PDCCH/PDSCH repetition transmissions, and N6 is the number of PUCCH repetition transmissions.

Specifically, when b2=b, the B-th PUCCH occasion in each group of PUCCH occasions is used for the UE located in the beam coverage area B to feed back ACK/NACK information of the TB, and for each beam coverage area B3, the MAC layer allocates resources to the PUCCH in the B3-th PUCCH occasion in each group of PUCCH occasions, and allocates the same PUCCH resources to PUCCH occasions in different groups; when b2=b1, the P-th PUCCH occasion in each group of PUCCH occasions is used for the UE located in the beam coverage area B1 (P) to feed back the ACK/NACK information of the TB, and when b3=b1 (P) is used for each beam coverage area B3, the MAC layer allocates resources to the PUCCH in the P-th PUCCH occasion in each group of PUCCH occasions, and allocates the same PUCCH resources to PUCCH occasions in different groups.

After step S504, step S505 or S506 is performed.

S505, when b2=b, the B-th PDCCH/PDSCH occasion in each set of PDCCH/PDSCH occasions is used to transmit PDCCH/PDSCH in the beam coverage area B, for each beam coverage area B3, the MAC layer allocates resources to PDCCH/PDSCH in the B3-th PDCCH/PDSCH occasion in each set of PDCCH/PDSCH occasions, and the PDSCH resources allocated in each PDSCH occasion are used to retransmit the TB when m=1, and are used to retransmit each code group requiring retransmission of the TB when M > 1; and transmitting PDCCH/PDSCH by using allocated PDCCH/PDSCH resources in the b3 rd PDCCH/PDSCH occasion in each group of PDCCH/PDSCH occasions, adopting a wave beam b3 when transmitting the PDCCH/PDSCH, scrambling the CRC of the PDCCH by using SPS G-RNTI when the TB is a TB carried by P-PTM, scrambling the CRC of the PDCCH by using the SPS G-RNTI when the TB is a TB carried by NP-PTM, adopting the G-RNTI when the PDSCH is scrambled by bits, carrying the TB on the PDSCH when the TB needs to be retransmitted in a wave beam coverage area b3, and carrying each code group of the TB which needs to be retransmitted on the PDSCH when at least one code group of the TB needs to be retransmitted in the wave beam coverage area b 3.

In this step, for any one of the beam coverage areas b3 of the TB to be retransmitted, resources are allocated to the PDCCH/PDSCH in the b3 rd PDCCH/PDSCH occasion corresponding to the beam coverage area b3 in each group of PDCCH/PDSCH occasions, for retransmitting the TB when m=1, and retransmitting each code group of the TB to be retransmitted when M > 1. For any one of the beam coverage areas b4 without retransmitting the TB, resources need not be allocated to the PDCCH/PDSCH in the b4 th PDCCH/PDSCH occasion corresponding to the beam coverage area b4 in each group of PDCCH/PDSCH occasions.

S506, when b2=b1, the P-th PDCCH/PDSCH occasion in each set of PDCCH/PDSCH occasions is used for transmitting PDCCH/PDSCH in beam coverage B1 (P), p=1, …, B1, and for each beam coverage B3, if b3=b1 (P), the MAC layer allocates resources to PDCCH/PDSCH in the P-th PDCCH/PDSCH occasion in each set of PDCCH/PDSCH occasions, the PDSCH resources allocated in each PDSCH occasion are used for retransmitting the TB when m=1, and retransmitting each code group requiring retransmission of the TB when M > 1; and transmitting PDCCH/PDSCH by adopting allocated PDCCH/PDSCH resources in the P-th PDCCH/PDSCH occasion in each group of PDCCH/PDSCH occasions, adopting a beam (P) when transmitting the PDCCH/PDSCH, scrambling the CRC of the PDCCH by adopting SPS G-RNTI when the TB is a TB borne by P-PTM, scrambling the CRC of the PDCCH by adopting the SPS G-RNTI when the TB is a TB borne by NP-PTM, adopting the G-RNTI when the PDSCH is subjected to bit scrambling, carrying the TB on the PDSCH when the TB needs to be retransmitted in a beam coverage area b3, and carrying each code group of the TB which needs to be retransmitted on the PDSCH when at least one code group of the TB needs to be retransmitted in the beam coverage area b 3.

In the above embodiments, the PUCCH in the PUCCH resource pool adopts format 0. Under preset conditions, in the above embodiments, the PUCCH in the PUCCH resource pool may also adopt format 1.

Specifically, when the PUCCH in the PUCCH resource pool may also employ format 1, the PUCCH in the PUCCH resource pool employs format 0 simultaneously or format 1 simultaneously. When the PUCCH in the PUCCH resource pool adopts the format 1 at the same time, when the NACK information of the TB is fed back through the corresponding PUCCH, the corresponding PUCCH is transmitted by adopting the format 1, and when the corresponding PUCCH is transmitted, 1 ACK/NACK bit is carried on the corresponding PUCCH, and the value of the bit is fixed to be 1 or 0 for processing. When format 1 is adopted, each PUCCH in the PUCCH resource pool is distinguished by a CS index and an orthogonal sequence code.

In the above embodiments, the feedback and retransmission method of the ACK/NACK information of the MBS HARQ process is described according to that only one TB is carried on the PDSCH. In fact, for an NP-PTM bearer, the PDSCH used to transmit the NP-PTM bearer may carry 2 TBs in some scenarios. The probability of transmitting 2 TBs of an NP-PTM bearer simultaneously over PDSCH is only very low. When 2 TBs are carried on PDSCH at the same time, as long as there are 1 TB decoding errors, the UE needs to feed back corresponding ACK/NACK information through PUCCH in the PUCCH resource pool. In order to support the scenario of simultaneously carrying 2 TBs on PDSCH, in the fourth embodiment, the number of PUCCHs M in the PUCCH resource pool needs to be increased correspondingly. The scenario for m=1 in embodiment four is exemplified as follows:

In the method described in the fourth embodiment, when m=1, there is only one TB on the PDSCH, and when the UE decodes the TB, the UE feeds back NACK information of the TB through the unique PUCCH in the PUCCH resource pool.

When there are 2 TBs on PDSCH, if m=1 is still maintained, when the UE decodes any one of 2 TBs, the UE needs to feed back NACK information through the unique PUCCH in the PUCCH resource pool, and after the corresponding PUCCH is received by the gNB, only 2 TBs can be retransmitted simultaneously.

When there are 2 TBs on PDSCH, if m=3 is set, when UE decodes any one of 2 TBs, UE selects one PUCCH from PUCCH resource pool for feeding back ACK/NACK information of two TBs: when the UE decodes the first TB, the UE transmits a PUCCH with the subscript of 1 in the PUCCH resource pool, when the UE decodes the second TB, the UE transmits a PUCCH with the subscript of 2 in the PUCCH resource pool, and when the UE decodes the 2 TB, the UE transmits a PUCCH with the subscript of 0 in the PUCCH resource pool.

Fig. 7 is a schematic structural diagram of a gNB according to a sixth embodiment of the present invention, as shown in fig. 7, the gNB100 includes:

a configuration module 11, configured to, for any multicast broadcast service MBS, configure a group radio network temporary identifier G-RNTI and a semi-static SPS G-RNTI for the MBS when the gNB determines to transmit the MBS by using a point-to-multipoint PTM bearer, determine to transmit a bandwidth portion BWP of the PTM bearer of the MBS, and configure a service data adaptation protocol SDAP entity, a packet data convergence protocol PDCP entity, and a radio link control RLC entity for the PTM bearer of the MBS;

A dividing module 12, configured to divide K radio bearers RB included in the PTM bearer into: K1P-RBs and/or K-K1 NP-RBs, wherein each P-RB has the characteristics of periodic transmission and fixed data quantity transmitted each time. The RB which is not the P-RB is NP-RB, the PTM bearer is split into K1P-PTM bearers and/or 1 NP-PTM bearer according to the RB type, each P-RB has a unique P-PTM bearer for transmitting the RB, and 1 NP-PTM bearer is used for transmitting all NP-RBs;

a determining module 13, configured to determine, when the MBS is a multicast service or the MBS is a broadcast service, but user equipment UE that receives a PTM bearer of the MBS is in a radio resource control RRC connected state, each beam coverage area that sends the PTM bearer according to a location of the RRC connected state UE that receives the PTM bearer, and determine, in each beam coverage area that sends the PTM bearer, a beam that is adopted when sending the PTM bearer;

a sending module 14, configured to send each P-PTM bearer and NP-PTM bearer of the PTM bearer on a BWP that sends the PTM bearer;

and a retransmission module 15, configured to aggregate NACK information of the TB of the P-PTM/NP-PTM bearer fed back by the UE for each of the P-PTM bearer and NP-PTM bearer of the PTM bearer, and retransmit the TB of the P-PTM/NP-PTM bearer.

In an exemplary manner, the method further includes a resource configuration module configured to:

the sending module 14 is specifically configured to: and sending each P-PTM bearer of the PTM bearer according to the semi-static PDSCH resource configuration information.

The sending module 14 sends each P-PTM bearer of the PTM bearers according to the semi-static PDSCH resource configuration information, specifically:

Wherein, in each period corresponding to the semi-static PDSCH resource, the frame number SFN of the starting radio frame satisfies the following equation:

(SFN)MOD(T)＝0

(SFN)MOD(T)＝SFN_OFFSET

ID＝INT(SFN/T)MOD H；

In another exemplary manner, the sending module 14 is specifically configured to:

the PUCCH resources allocated for the NP-PTM bearer include B2×n4 PUCCH occasions, the time-frequency resources allocated for the PUCCH in each PUCCH occasion are the same, N4 is the number of repeated transmissions of the PUCCH, the time-frequency resources of the B2×n4 PUCCH occasions are the same, the B2×n4 PUCCH occasions are divided into N4 groups, and each group includes B2 consecutive PUCCH occasions;

When a dynamic PUCCH resource pool is configured for the NP-PTM bearer, designating resource index of M PUCCHs through PDCCH each time when the MAC layer schedules the NP-PTM bearer, giving out resource index of first PUCCH in the PUCCH resource pool by a PUCCH resource index field in a DCI format on PDCCH, distributing continuous M resource index to M PUCCHs in the PUCCH resource pool from the resource index, and the DCI format has the same PUCCH resource index field on PDCCH in each PDCCH occasion;

The sending module 14 sends the NP-PTM bearer using the PDCCH resources and the PDSCH resources allocated for the NP-PTM bearer, specifically:

The retransmission module 15 is specifically configured to:

monitoring each PUCCH in a PUCCH resource pool configured for the bearing in each PUCCH occasion in each group of PUCCH occasions configured for the P-PTM/NP-PTM bearing;

stopping subsequent processing when the fact that retransmission of the TB is not needed is determined according to the monitoring result, otherwise, determining that retransmission of each beam coverage area of the TB is needed, and further determining that each code group needing retransmission in each beam coverage area of the TB is needed when M >1, wherein b3 represents any subscript of the beam coverage area needing retransmission of the TB;

The MAC layer retransmits the TB in a dynamic scheduling mode, specifically:

Specifically, when b2=b, the B-th PUCCH occasion in each group of PUCCH occasions is used for the UE located in the beam coverage area B to feed back ACK/NACK information of the TB, and for each beam coverage area B3, the MAC layer allocates resources to the PUCCH in the B3-th PUCCH occasion in each group of PUCCH occasions, and allocates the same PUCCH resources to PUCCH occasions in different groups;

The gcb provided in this embodiment may be used to execute the method steps executed by the gcb in the first embodiment to the fifth embodiment, and detailed implementation manner is not repeated.

Fig. 8 is a schematic structural diagram of a UE according to a seventh embodiment of the present invention, as shown in fig. 8, where the UE provided in this embodiment includes:

a receiving module 21, configured to receive each P-PTM bearer and NP-PTM bearer of a point-to-multipoint PTM bearer of a multicast broadcast service MBS sent by the gNB;

and a feedback module 22, configured to generate NACK information of the TB when the UE decodes the transport block TB carried by the P-PTM/NP-PTM in error, and feedback the NACK information of the TB through the physical uplink control channel PUCCH corresponding to the P-PTM/NP-PTM carried by the P-PTM/NP-PTM.

In an exemplary manner, the feedback module 22 is specifically configured to:

determining the PUCCH time for transmitting the PUCCH, and transmitting the PUCCH in the corresponding PUCCH time.

The feedback module 22 is specifically configured to:

when m=1, when the UE decodes the TB carried by the P-PTM/NP-PTM with an error, determining to transmit a unique PUCCH in the PUCCH resource pool.

At m=2 ^C -1, C is the maximum number of blocks supported by one TB;

and dividing the TB borne by the P-PTM/NP-PTM into C code groups, and feeding back ACK/NACK information of each code group when the UE decodes the TB in error.

Dividing the TB carried by the P-PTM/NP-PTM into C code groups, and feeding back ACK/NACK information of each code group by the UE when the UE decodes the TB in error, wherein the ACK/NACK information is specifically:

when the UE decodes the TB carried by the P-PTM/NP-PTM, dividing the TB into C code groups, generating a bit sequence with the length of C bits, wherein the C bit in the bit sequence corresponds to the C code group according to the left-right order, and when the UE decodes the C code group correctly, the value of the C bit is 1; otherwise, the value of the c-th bit is 0; c=1, …, C;

And determining a decimal value V corresponding to the bit sequence, selecting a PUCCH with a subscript V from M PUCCHs contained in the PUCCH resource pool according to the decimal value V, and sending the PUCCH.

And when M=3, dividing the TB into C=2 code groups by the UE when the TB carried by the P-PTM/NP-PTM is decoded by the UE, transmitting a PUCCH with the subscript of 0 in the PUCCH resource pool when the TB is decoded by the UE by the P-PTM/NP-PTM, transmitting a PUCCH with the subscript of 2 in the PUCCH resource pool when the TB is decoded by the UE by the first code group, and transmitting a PUCCH with the subscript of 1 in the PUCCH resource pool when the TB is decoded by the UE by the second code group.

At m=7, when the UE decodes the TB carried by the P-PTM/NP-PTM, the UE divides the TB into c=4 code groups, and when the UE decodes only the C-th code group, the UE transmits PUCCH with index C in the PUCCH resource pool, c=1, 2,3,4; when the UE decodes the first two code groups in error, the UE transmits a PUCCH with the subscript of 5 in the PUCCH resource pool; when the UE decodes the last two code groups in error, sending a PUCCH with the subscript of 6 in the PUCCH resource pool; and when the UE decodes errors on all four code groups, sending a PUCCH with the subscript of 0 in the PUCCH resource pool.

The UE provided in this embodiment may be used to perform the method steps performed by the UE in the first to fifth embodiments, and detailed implementation is not repeated.

Fig. 9 is a schematic structural diagram of a gNB according to an eighth embodiment of the present invention, as shown in fig. 9, the gNB300 includes: a processor 31, a memory 32 and a transceiver 33, the memory 32 being for storing instructions, the transceiver 33 being for communicating with other devices, the processor 31 being for executing the instructions stored in the memory to cause the gNB300 to perform the method as performed by the gNB in the method embodiments described above.

A ninth embodiment of the present invention provides a UE, where the structure of the UE may be shown in fig. 9, where the memory 32 is configured to store instructions, the transceiver 33 is configured to communicate with other devices, and the processor 31 is configured to execute the instructions stored in the memory 32, so that the UE may perform a method performed by the UE in the foregoing method embodiment.

As an embodiment, the base station or UE may include multiple processors. Each of these processors may be a single-core processor (single-CPU) or a multi-core processor (multi-CPU). The processor may be a Digital Signal Processor (DSP), a general purpose microprocessor, an Application Specific Integrated Circuit (ASIC), a field programmable logic array (FPGA), or other equivalent integrated or discrete logic circuitry, or the like.

An embodiment of the present invention provides a computer readable storage medium, where instructions are stored in the computer readable storage medium, and when the instructions are executed, the instructions cause a computer to execute a method executed by a gNB in the foregoing method embodiment, and a specific implementation is not described herein.

An eleventh embodiment of the present invention provides a computer readable storage medium, where instructions are stored in the computer readable storage medium, and when the instructions are executed, the computer is caused to execute a method executed by a UE in the foregoing method embodiment, and a specific implementation is not described in detail.

The foregoing is merely illustrative of the embodiments of the present invention, and the scope of the present invention is not limited thereto, and any changes or substitutions easily contemplated by those skilled in the art within the technical scope of the present invention should be included in the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. The feedback and retransmission method of ACK/NACK information of MBS is characterized by being applied to gNB, and comprises the following steps:

for any multicast broadcast service MBS, when gNB determines to transmit the MBS by using a point-to-multipoint PTM bearer, configuring a group radio network temporary identifier G-RNTI and a semi-static SPS G-RNTI for the MBS, determining a bandwidth part BWP for transmitting the PTM bearer of the MBS, and configuring a service data adaptation protocol SDAP entity, a packet data convergence protocol PDCP entity and a radio link control RLC entity for the PTM bearer of the MBS;

Dividing K radio bearers RB included in the PTM bearer into: K1P-RBs and/or K1 NP-RBs, wherein each P-RB has the characteristics of periodic transmission and fixed data quantity transmitted each time, the RBs which are not P-RBs are NP-RBs, the PTM bearer is split into K1P-PTM bearers and/or 1 NP-PTM bearer according to the type of the RB, each P-RB has a unique P-PTM bearer and is used for transmitting the RB, and 1 NP-PTM bearer is used for transmitting all NP-RBs;

for each P-PTM bearer and NP-PTM bearer of the PTM bearer, gNB gathers NACK information of the TB of the P-PTM/NP-PTM bearer fed back by UE, and retransmits the TB of the P-PTM/NP-PTM bearer;

the method further comprises the steps of:

transmitting each P-PTM bearer of the PTM bearer according to the semi-static PDSCH resource configuration information;

the sending each P-PTM bearer of the PTM bearers according to the semi-static PDSCH resource configuration information includes:

when the MBS is a multicast service, or when the MBS is a broadcast service and the UE receiving the PTM bearer is in an RRC connection state, b2=b1, the MAC layer uses allocated PDSCH resources in the ith PDSCH occasion in each group of PDSCH occasions to transmit the PDSCH, uses Beam (i) when transmitting the PDSCH, and carries the TB on the PDSCH, and uses SPS G-RNTI when bit scrambling, when B1< B, or when the value of B1 changes, the UE is notified of the Beam coverage area of the PTM bearer by MAC CE or PDCCH uplink/downlink control information DCI format.

2. The method of claim 1, wherein a frame number SFN of a starting radio frame satisfies the following equation in each period corresponding to the semi-static PDSCH resources:

(SFN)MOD(T)＝0

(SFN)MOD(T)＝SFN_OFFSET

ID＝INT(SFN/T)MOD H；

3. The method of claim 2 wherein transmitting the NP-PTM bearer of the PTM bearer over the BWP transmitting the PTM bearer comprises:

each time the MAC layer dispatches the NP-PTM bearer, physical Downlink Control Channel (PDCCH) resource, physical downlink control channel (PDSCH) resource and Physical Uplink Control Channel (PUCCH) resource are allocated for the NP-PTM bearer, a TB is formed by MAC PDU carried by the NP-PTM according to the allocated PDSCH resource, the NP-PTM bearer is used for transmitting all NP-RBs, the MAC PDU carried by the NP-PTM is multiplexed by MAC SDUs on each NP-RB, and the MAC layer selects an idle HARQ process for the TB and transmits the TB through the process;

the PUCCH resources allocated for the NP-PTM bearer are formed by B2 x N4 PUCCH opportunities, the B2 x N4 PUCCH opportunities are divided into N4 groups, each group comprises B2 continuous PUCCH opportunities, N4 is the repetition transmission times of PUCCH, the same time-frequency resources are allocated for the PUCCH in each PUCCH opportunity, the time-frequency resources are determined by a starting symbol index 1, the number of symbols 1, PRB bias 1 and CS index set 1, the PUCCH transmitted on the allocated time-frequency resources in each PUCCH opportunity is given by a PUCCH resource pool, the PUCCH resource pool is formed by M PUCCHs, and each PUCCH adopts a format 0;

4. The method of claim 3, wherein transmitting the NP-PTM bearer using the PDCCH resources and the PDSCH resources allocated for the NP-PTM bearer comprises:

5. The method of claim 4 wherein for each of the P-PTM bearer and the NP-PTM bearer of the PTM bearer, the gNB aggregates NACK information for TBs of the P-PTM/NP-PTM bearers fed back by the UE, retransmits the TBs of the P-PTM/NP-PTM bearers, comprising:

the gNB monitors each PUCCH in the PUCCH resource pool configured for the P-PTM/NP-PTM in each PUCCH occasion in each group of PUCCH occasions configured for the P-PTM/NP-PTM;

when the gNB determines that the TB is not required to be retransmitted according to the monitoring result, the gNB stops subsequent processing, otherwise, the gNB determines that each beam coverage area of the TB is required to be retransmitted, when M >1, the gNB further determines each code group which is required to be retransmitted in each beam coverage area of the TB, and b3 represents the subscript of any beam coverage area which is required to be retransmitted;

6. The method of claim 5 wherein the MAC layer re-transmits the TBs in each beam coverage area b3 using dynamic scheduling, comprising:

7. The method of claim 6 wherein when b2=b, the B-th PUCCH occasion in each group of PUCCH occasions is used for the UE located in beam coverage B to feed back ACK/NACK information of the TB, and for each beam coverage B3, the MAC layer allocates resources to the PUCCH in the B3-th PUCCH occasion in each group of PUCCH occasions, and allocates the same PUCCH resources to PUCCH occasions in different groups;

8. The feedback and retransmission method of ACK/NACK information of MBS is characterized by being applied to User Equipment (UE), and comprises the following steps:

when the UE decodes the Transport Block (TB) carried by the P-PTM/NP-PTM in error, the UE generates NACK information of the TB and feeds back the NACK information of the TB through a Physical Uplink Control Channel (PUCCH) corresponding to the P-PTM/NP-PTM;

when the UE decodes the transport block TB carried by the P-PTM/NP-PTM in error, the UE generates NACK information of the TB and feeds back the NACK information of the TB through a Physical Uplink Control Channel (PUCCH) corresponding to the P-PTM/NP-PTM, comprising:

9. The method of claim 8 wherein the determining, when the UE decodes the TB of the P-PTM/NP-PTM bearer in error, a PUCCH to be transmitted from a PUCCH resource pool according to a number M of PUCCHs included in the PUCCH resource pool allocated to the P-PTM/NP-PTM bearer and a preset criterion for feeding back ACK/NACK information of the TB of the P-PTM/NP-PTM bearer, the PUCCH being used for feeding back the ACK/NACK information of the TB to the gNB, comprises:

10. The method of claim 8 wherein the determining, when the UE decodes the TB of the P-PTM/NP-PTM bearer in error, a PUCCH to be transmitted from a PUCCH resource pool according to a number M of PUCCHs included in the PUCCH resource pool allocated to the P-PTM/NP-PTM bearer and a preset criterion for feeding back ACK/NACK information of the TB of the P-PTM/NP-PTM bearer, the PUCCH being used for feeding back the ACK/NACK information of the TB to the gNB, comprises:

M＝2 ^C -1, c is the maximum number of code groups supported by one TB;

11. The method of claim 10 wherein the UE groups TBs of the P-PTM/NP-PTM bearer into C groups, and wherein when the UE decodes the TBs in error, the UE feeds back ACK/NACK information for each group, comprising:

12. The method of claim 8 wherein the determining, when the UE decodes the TB of the P-PTM/NP-PTM bearer in error, a PUCCH to be transmitted from a PUCCH resource pool according to a number M of PUCCHs included in the PUCCH resource pool allocated to the P-PTM/NP-PTM bearer and a preset criterion for feeding back ACK/NACK information of the TB of the P-PTM/NP-PTM bearer, the PUCCH being used for feeding back the ACK/NACK information of the TB to the gNB, comprises:

13. The method of claim 8 wherein the determining, when the UE decodes the TB of the P-PTM/NP-PTM bearer in error, a PUCCH to be transmitted from a PUCCH resource pool according to a number M of PUCCHs included in the PUCCH resource pool allocated to the P-PTM/NP-PTM bearer and a preset criterion for feeding back ACK/NACK information of the TB of the P-PTM/NP-PTM bearer, the PUCCH being used for feeding back the ACK/NACK information of the TB to the gNB, comprises:

14. A gNB comprising a processor, a memory to store instructions, and a transceiver to communicate with other devices, the processor to execute the instructions stored in the memory to cause the base station to perform the method of any of claims 1-7.

15. A UE comprising a processor, a memory for storing instructions, and a transceiver for communicating with other devices, the processor for executing the instructions stored in the memory to cause the UE to perform the method of any of claims 8-13.

16. A computer readable storage medium storing instructions that, when executed, cause a computer to perform the method of any one of claims 1-7.

17. A computer readable storage medium storing instructions that, when executed, cause a computer to perform the method of any one of claims 8-13.