CN111954307A

CN111954307A - Communication method and device in wireless communication network

Info

Publication number: CN111954307A
Application number: CN201910412965.4A
Authority: CN
Inventors: 王轶; 付景兴; 吴敏; 孙霏菲
Original assignee: Beijing Samsung Telecommunications Technology Research Co Ltd; Samsung Electronics Co Ltd
Current assignee: Beijing Samsung Telecom R&D Center; Beijing Samsung Telecommunications Technology Research Co Ltd; Samsung Electronics Co Ltd
Priority date: 2019-05-17
Filing date: 2019-05-17
Publication date: 2020-11-17

Abstract

Terminals and base stations in a wireless communication network and methods performed by the terminals and base stations are disclosed. According to one embodiment, a method performed by a terminal in a wireless communication network, comprises: receiving a Physical Downlink Control Channel (PDCCH), wherein the PDCCH comprises Downlink Control Information (DCI) used for scheduling one or more Physical Downlink Shared Channels (PDSCHs); receiving the PDSCH according to the DCI; and transmitting a hybrid automatic repeat request acknowledgement (HARQ-ACK/NACK) codebook for the PDSCH.

Description

Communication method and device in wireless communication network

Technical Field

The present application relates to the field of wireless communication technologies, and in particular, to a communication method and apparatus in a wireless communication network.

Background

In a wireless communication system, transmission of a physical Downlink Shared channel pdsch (physical Downlink Shared channel) and a physical Uplink Shared channel pusch (physical Uplink Shared channel) is scheduled by Downlink Control information dci (Downlink Control information) transmitted through a physical Downlink Control channel pdcch (physical Downlink Control channel). One DCI may schedule a single PDSCH or PUSCH, or may simultaneously schedule multiple PDSCHs or PUSCHs.

Disclosure of Invention

According to an aspect, there is provided a method performed by a terminal in a wireless communication network, comprising: receiving a Physical Downlink Control Channel (PDCCH), wherein the PDCCH comprises Downlink Control Information (DCI) used for scheduling one or more Physical Downlink Shared Channels (PDSCHs); receiving the PDSCH according to the DCI; and transmitting a hybrid automatic repeat request acknowledgement (HARQ-ACK/NACK) codebook for the PDSCH.

In an exemplary embodiment, the DCI includes a downlink assignment index DAI, and in a case where one DCI schedules a plurality of PDSCHs, the DAI indicates information of a first PDSCH of the plurality of PDSCHs or information of a last PDSCH of the plurality of PDSCHs.

In an exemplary embodiment, the DCI includes a downlink assignment index DAI, and in a case where a plurality of PDSCHs scheduled by one PDCCH belong to one or more PDSCH groups, the DAI includes one or more DAI bit fields, each of which corresponds to DAI information of one PDSCH group, respectively.

In an exemplary embodiment, before transmitting the HARQ-ACK/NACK codebook, the method further comprises: grouping a plurality of PDSCHs which are fed back in one HARQ-ACK/NACK codebook according to a DCI format for scheduling each PDSCH in the plurality of PDSCHs, wherein the PDSCHs scheduled by the same DCI format belong to the same PDSCH group; and determining a codebook for each PDSCH group.

In an exemplary embodiment, the method further comprises: grouping a plurality of PDSCHs fed back in one HARQ-ACK/NACK codebook according to the number of the PDSCHs scheduled by each DCI scheduling the plurality of PDSCHs, wherein the PDSCHs scheduled by the DCI of which the number of the scheduled PDSCHs is larger than a threshold value and the PDSCHs scheduled by the DCI of which the number of the scheduled PDSCHs is equal to or smaller than the threshold value belong to different PDSCH groups; and determining a codebook for each PDSCH group.

In an exemplary embodiment, before transmitting the HARQ-ACK/NACK codebook, the method further comprises: grouping a plurality of PDSCHs fed back in one HARQ-ACK/NACK codebook according to transmission granularity, wherein the PDSCHs with the same transmission granularity belong to the same PDSCH group, the PDSCHs with different transmission granularity belong to different PDSCH groups, or the PDSCHs with different granularity belong to the same PDSCH group determined according to the transmission granularity of a reference PDSCH; and determining a codebook for each PDSCH group.

In an exemplary embodiment, determining the codebook for each PDSCH group comprises: and determining the HARQ-ACK/NACK codebook of each PDSCH group according to the DAI of the PDSCH in each PDSCH group and the HARQ-ACK/NACK bit number corresponding to each PDSCH in each PDSCH group.

In an exemplary embodiment, the DCI includes a downlink assignment index DAI for counting a PDCCH, and when the number of HARQ-ACK/NACK bits of each PDSCH is N_{max_p}The maximum number of PDSCHs belonging to the same PDSCH group scheduled by one PDCCH is N_{max_pdsch}And when the DAI value in the PDSCH group is M, the number of HARQ-ACK/NACK bits N corresponding to the PDCCH_t＝N_{max_p}×N_{max_pdsch}The total number of bits of the transmitted HARQ-ACK/NACK codebook is MxN_t＝M×N_{max_p}×N_{max_pdsch}。

In an exemplary embodiment, the DCI includes a downlink assignment index DAI for counting PDSCHs, where the DAI indicates information of a last PDSCH of the plurality of PDSCHs scheduled by the DCI, when each PDSCH includes a downlink assignment index DAI for counting PDSCHsHARQ-ACK/NACK bit number of PDSCH is N_{max_p}And when the DAI value in one PDSCH group is M, the total number of bits of the HARQ-ACK/NACK codebook to be transmitted is M × N_{max_p}。

In an exemplary embodiment, the DCI includes a downlink assignment index DAI for counting PDCCHs, and when a HARQ-ACK/NACK bit number N corresponding to one PDCCH is greater than a predetermined value_tThe total number of bits of the HARQ-ACK/NACK codebook transmitted is M × N, and the DAI value in one PDSCH group is M_tIn which N is_tIs pre-defined or semi-statically configured, and N_tNot less than the sum of HARQ-ACK/NACK bit numbers of each PDSCH scheduled by the PDCCH

Where Ni is the number of HARQ-ACK/NACK bits for the ith PDSCH scheduled by the one PDCCH.

In an exemplary embodiment, the number of HARQ-ACK/NACK bits per PDSCH is N_{max_p}The number of effective HARQ-ACK/NACK bits per PDSCH is N_{r_p}Determining the value of effective HARQ-ACK/NACK according to the decoding result of PDSCH, wherein the value is N_{r_p}Less than N_{max_p}In case of (2), remaining (N) of HARQ-ACK/NACK_{max_p}-N_{r_p}) The value of the bit is determined according to a predefined value; and/or the number of HARQ-ACK/NACK bits corresponding to each PDCCH is N_t＝N_{max_p}×N_{max_pdsch}The number of PDSCH scheduled by each PDCCH is N_pdschAccording to N_pdschDetermining N from the decoding result of PDSCH_{max_p}×N_pdschTaking the value of HARQ-ACK/NACK of a bit at N_{max_p}×N_pdschLess than N_tIn case of HARQ-ACK/NACK, the remaining N of the HARQ-ACK/NACK_{max_p}×(N_{max_pdsch}-N_pdsch) The value of the bit is determined according to a predefined value.

In an exemplary embodiment, the DCI includes ZP CSI-RS information, which is zero power channel reference information pilot, wherein in case that one DCI schedules a plurality of PDSCHs, the plurality of PDSCHs are rate-matched according to the ZP CSI-RS information.

In an exemplary embodiment, rate matching the plurality of PDSCHs according to ZP CSI-RS information comprises at least one of: performing rate matching on each PDSCH in the plurality of PDSCHs according to the ZP CSI-RS information, performing rate matching on the PDSCH of each downlink time unit according to the ZP CSI-RS information, performing rate matching on only the first PDSCH according to the ZP CSI-RS information, performing rate matching on the PDSCH in the scheduled first time unit according to the ZP CSI-RS information, and performing rate matching on the PDSCH overlapped with the ZP CSI-RS information according to the ZP CSI-RS information.

In an exemplary embodiment, the DCI includes control channel resource set (CORESET) information, where the CORESET information includes a plurality of CORESETs for DCI capable of scheduling a plurality of PDSCHs.

In an exemplary embodiment, the DCI receiving the PDSCH further comprises: receiving a demodulation reference signal (DMRS) of the PDSCH according to the DCI, and receiving the PDSCH according to the DMRS, wherein the DCI indicates a pattern of the DMRS, and the pattern of the DMRS comprises one or more of period information, time offset information, a time length and a symbol position index.

In an exemplary embodiment, receiving the PDSCH according to the DCI further comprises: receiving demodulation reference signals (DMRS) of the PDSCH according to the DCI, and receiving the PDSCH according to the DMRS, wherein the DCI indicates position information of the DMRS, and the position information of the DMRS is determined by time domain information of each PDSCH; alternatively, the time domain information of all PDSCHs scheduled by the DCI of one PDCCH is determined in common.

The application also provides a terminal for executing the method.

According to another aspect, there is provided a method performed by a terminal in a wireless communication network, comprising: transmitting a Physical Downlink Control Channel (PDCCH), wherein the PDCCH comprises Downlink Control Information (DCI) used for scheduling one or more Physical Downlink Shared Channels (PDSCHs); transmitting the PDSCH according to the DCI; and receiving a hybrid automatic repeat request acknowledgement (HARQ-ACK/NACK) codebook for the PDSCH.

In an exemplary embodiment, the DCI includes a downlink assignment index DAI for counting PDSCHs, where the DAI indicates information of a last PDSCH in a plurality of PDSCHs scheduled by the DCI, and when the number of HARQ-ACK/NACK bits of each PDSCH is N_{max_p}And when the DAI value in one PDSCH group is M, the total number of bits of the HARQ-ACK/NACK codebook to be transmitted is M × N_{max_p}。

Wherein Ni isAnd the number of HARQ-ACK/NACK bits of the ith PDSCH scheduled by the PDCCH.

In an exemplary embodiment, transmitting the PDSCH according to the DCI further includes: and transmitting a demodulation reference signal (DMRS) of the PDSCH according to the DCI, and transmitting the PDSCH according to the DMRS, wherein the DCI indicates a pattern of the DMRS, and the pattern of the DMRS comprises one or more of period information, time offset information, a time length and a symbol position index.

In an exemplary embodiment, transmitting the PDSCH according to the DCI further includes: transmitting a demodulation reference signal (DMRS) of the PDSCH according to the DCI, and transmitting the PDSCH according to the DMRS, wherein the DCI indicates position information of the DMRS, and the position information of the DMRS is determined by time domain information of each PDSCH; alternatively, the time domain information of all PDSCHs scheduled by the DCI of one PDCCH is determined in common.

The application also provides a base station for executing the method.

Furthermore, the present application also provides a computer-readable storage medium storing computer instructions, which, when executed by a processor, can cause the processor to perform the above-mentioned method performed by a terminal or a base station in a wireless communication network.

Drawings

Fig. 1 shows an example of a signal flow transmitted between a terminal and a base station according to an embodiment of the present application.

Fig. 2 illustrates an example of a HARQ-ACK/NACK feedback bundling window and a HARQ-ACK/NACK codebook according to example one.

Fig. 3 shows an example of a HARQ-ACK/NACK feedback bundling window and a HARQ-ACK/NACK codebook according to example two.

Fig. 4 shows an example of a HARQ-ACK/NACK feedback bundling window and a HARQ-ACK/NACK codebook according to example three.

Fig. 5 illustrates an example of a HARQ-ACK/NACK feedback bundling window and a HARQ-ACK/NACK codebook according to example six.

Fig. 6 illustrates an example of a HARQ-ACK/NACK feedback bundling window and a HARQ-ACK/NACK codebook according to example seven.

FIG. 7 shows a schematic block diagram of a device that may be configured to practice exemplary embodiments of the present application.

Detailed Description

The present application will be described in further detail with reference to the following drawings and examples. It is to be understood that the specific examples described herein are for purposes of illustration only and are not intended to limit the disclosure.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.

The terminology used in the present disclosure is for describing particular embodiments and is not intended to limit the scope of other embodiments. A statement that a quantity is not explicitly stated may generally be one or more unless explicitly stated otherwise. All terms used herein, including technical and scientific terms, may have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

In the following description, a base station is an access device that accesses a communication device to a cellular network, and is used to allocate communication resources to the communication device. The base station may be any of the following entities: a gNB, ng-eNB, radio access unit, base station controller, base transceiver station, etc. The communication device may be any device intended to access services via an access network and capable of being configured for communication over the access network. For example, communication devices may include, but are not limited to: a user terminal UE, a mobile station MS, a cellular phone, a smart phone, a computer, or a multimedia system equipped with communication functions. It should be noted that in the following description, the terms "communication device", "user equipment", "user terminal", "terminal" and "UE" may be used interchangeably.

It should be understood that the embodiments disclosed herein may be applied in various types of cellular networks.

Fig. 1 shows an example of a signal flow transmitted between a terminal 10 and a base station 20 according to an embodiment of the present application. One skilled in the art will understand that one or more specific technical details are provided in the following description for purposes of example and ease of understanding, but that embodiments of the present application may also be practiced without these features.

In step 101: the terminal 10 receives the PDCCH from the base station 20. The received PDCCH may include DCI for scheduling one or more PDSCHs.

In step 102: the terminal 10 receives the PDSCH from the base station 20 according to the received DCI.

In step 103: the terminal 10 transmits a hybrid automatic repeat request acknowledgement HARQ-ACK/NACK codebook for the PDSCH to the base station 20.

According to one embodiment, the DCI of the PDCCH may include at least one of: information on a coding block group cbg (coding block group), information on rate matching, information on a demodulation reference signal dmrs (demodulation reference signal), information on HARQ-ACK/NACK timing, and information on a downlink assignment index dai (downlink assignment index), and the like. According to receiving the PDCCH, the terminal 10 may determine at least one of time-frequency resource information, rate matching information, HARQ-ACK/NACK feedback information, transport block group information, and reference information of the PDSCH scheduled by the PDCCH, and receive the PDSCH from the base station 20 and perform HARQ-ACK/NACK feedback according to the above information.

The DCI of the PDCCH may include information on a coding block group CBG. For example, the information includes coding block transmission information cbgti (cbg transmission information), and/or information cbgfi (cbg flushing out information) indicating whether the coding block may be contaminated. CBGTI and/or CBGFI for each PDSCH may be independently indicated if one DCI can schedule M PDSCHs; or CBGTI and/or CBGFI for N PDSCHs of the M PDSCHs are independently indicated, where N is based on a predefined or signaling configuration. The UE may determine which N PDSCHs of the M PDSCHs according to the indication of the base station, or determine which N PDSCHs of the M PDSCHs are according to special values of other bit fields in the DCI, for example, by whether a new data indication ndi (new data indicator) is flipped; alternatively, M PDSCHs share one CBGTI and/or CBGFI bit field.

The DCI of the PDCCH may include information on rate matching. The information on rate matching may be, for example, rate matching information based on the granularity of resource elements REs. Alternatively, the information on rate matching may be rate matching information based on a control channel resource set (coreset).

If the base station configures rate matching information with granularity based on Resource Elements (REs), such as zero power channel reference information (ZP) CSI-RS (zero power channel state information) for example, the PDSCH cannot be mapped to the ZP CSI-RS position indicated in the DCI. If one DCI schedules a plurality of PDSCHs, each PDSCH performs rate matching according to the indicated same aperiodic ZP CSI-RS information, or the PDSCH of each downlink time unit performs rate matching according to the indicated same aperiodic ZP CSI-RS information, or only the first PDSCH performs rate matching according to the indicated aperiodic ZP CSI-RS information, or only the PDSCH in the scheduled first time unit performs rate matching according to the indicated aperiodic ZP CSI-RS information; or performing rate matching on the PDSCH overlapped with the aperiodic ZP CSI-RS information according to the aperiodic ZP CSI-RS information. The downlink time unit may be one or more slots, mini-slots, sub-slots, or OFDM symbols.

For example, according to a rule that each PDSCH performs rate matching according to the indicated same aperiodic ZP CSI-RS information, if 4 PDSCHs are scheduled by one DCI, and the 4 PDSCHs respectively occupy 1 to 3, 4 to 6, 7 to 9 and 10 to 12 symbols in the same downlink time slot, and the DCI indicates that the aperiodic ZP CSI-RS has an offset of 1 symbol relative to a starting symbol of the PDSCH and the aperiodic ZP CSI-RS occupies 2 continuous symbols, the 4 PDSCHs respectively avoid resources of the aperiodic ZP CSI-RS in the 2 to 3, 5 to 6, 8 to 9 and 11 to 12 symbols.

For example, according to a rule that the PDSCH of each downlink time unit performs rate matching according to the indicated same aperiodic ZP CSI-RS information, if one DCI schedules 4 PDSCHs, and the 4 PDSCHs respectively occupy the 1 st to 7 th and 8 th to 14 th symbols of a first downlink time slot and the 1 st to 7 th and 8 th to 14 th symbols of a second downlink time slot in consecutive 2 downlink time slots, and the DCI indicates the 8 th to 9 th symbols of the aperiodic ZP CSI-RS in one time slot, only the 2 nd and 4 nd PDSCHs respectively avoid the aperiodic ZP CSI-RS resources in the 8 th to 9 symbols of the first time slot and the second time slot.

For example, according to a rule of performing rate matching on a PDSCH overlapping with aperiodic ZP CSI-RS information according to the aperiodic ZP CSI-RS information, the base station may configure a set of combinations of aperiodic ZP CSI-RS included in multiple PDSCHs or multiple downlink time units, and indicate one of the combinations through DCI. Optionally, for DCI with only a single schedulable PDSCH and multiple schedulable PDSCHs, the base station may configure the aperiodic ZP CSI-RS set independently. For example, for DCI with only a single schedulable PDSCH, the aperiodic ZP CSI-RS sets configured by the base station are all applicable to 1 PDSCH. For DCI that can schedule multiple PDSCHs, the aperiodic ZP CSI-RS set configured by the base station may be applicable to the multiple PDSCHs. For example, in DCI capable of scheduling multiple PDSCHs, a 2-bit aperiodic ZP CSI-RS indication corresponds to 3 aperiodic ZP CSI-RS combinations, where combination 1 indicates that the first 3 PDSCHs have one aperiodic ZP CSI-RS group respectively, combination 2 indicates that the 1 st PDSCH has one aperiodic ZP CSI-RS group respectively, and combination 3 indicates that all PDSCHs have one aperiodic ZP CSI-RS group respectively. The base station dynamically indicates different combinations by these 2 bits. If the DCI schedules 4 PDSCHs and combination 1 is indicated, then the first 3 PDSCHs need to avoid the indicated aperiodic ZP CSI-RS and the 4 th PDSCH need not be avoided.

If the base station configures rate matching information based on the control channel resource set CORESET, the base station may independently configure the CORESET for DCI that may schedule only a single PDSCH and may schedule multiple PDSCHs. For example, for DCI that can only schedule a single PDSCH, only 1 CORESET is included in the set of CORESET configured by the base station. For the DCI capable of scheduling multiple PDSCHs, the set of CORESET configured by the base station includes multiple CORESETs. From the time resource information of the configured set of CORESET, it can be determined at which PDSCHs and at which locations of the PDSCHs the rate matching is performed.

The DCI of the PDCCH may include information on a demodulation reference signal DMRS for indicating a location of the DMRS and pattern information. With respect to DMRS, it will be described in further detail below.

The DCI of the PDCCH may include information on HARQ-ACK/NACK timing.

Optionally, when one DCI schedules multiple PDSCHs, HARQ-ACK/NACK of each PDSCH corresponds to the same uplink time unit. In this case, only one HARQ-ACK/NACK timing information bit field is needed in the DCI. The uplink time unit may be determined according to the HARQ-ACK/NACK timing information with a first PDSCH or a last PDSCH of the scheduled multiple PDSCHs as a time reference.

Optionally, HARQ-ACK/NACK of each PDSCH scheduled by one DCI may correspond to different uplink time units. According to one implementation, only one HARQ-ACK/NACK timing information bit field is needed in the DCI, indicating one HARQ-ACK/NACK timing information for determining an uplink time unit of a first PDSCH of the scheduled multiple PDSCHs. The DCI may further include a bit field indicating a time offset of an uplink time unit of each PDSCH, so that the uplink time unit of each PDSCH can be determined. Alternatively, the time offset may be configured by higher layer signaling, without indication in the DCI. According to another implementation, only one HARQ-ACK/NACK timing information bit field is needed in the DCI, indicating HARQ-ACK/NACK timing information for multiple PDSCHs. The base station may configure a set of HARQ-ACK/NACK timing information combinations for multiple PDSCHs through higher layer signaling, and indicate one of the combinations through a HARQ-ACK/NACK timing information bit field of DCI.

The DCI of the PDCCH may include information on a downlink allocation index DAI. For example, one or more of the first type of DAI, the second type of DAI, and the third type of DAI described below may be included in the DCI.

The first type of DAI may be referred to as a counter DAI or a C-DAI (counter-DAI), and is used to indicate information of a sum of the number of scheduled PDSCHs up to the current PDCCH within a HARQ-ACK/NACK feedback bundling window; and/or information of the sum of the numbers of PDCCHs transmitted up to the current PDCCH within the HARQ-ACK/NACK feedback bundling window. That is, the count information of the scheduled PDSCH or the transmitted PDCCH up to the current PDCCH within the HARQ-ACK/NACK feedback bundling window.

Optionally, the sum of the numbers of PDCCHs transmitted up to the current PDCCH is determined according to the sum of the numbers of PDCCHs up to the current carrier and the current PDCCH within the current PDCCH monitoring opportunity. If there are multiple PDCCHs corresponding to the same carrier in the same PDCCH monitoring opportunity, the multiple PDCCHs are counted according to a predefined rule.

Optionally, the sum of the number of scheduled PDSCHs up to the current PDCCH is determined according to the sum of PDCCH scheduled PDSCHs up to the current carrier and the current PDCCH within the current PDCCH monitoring opportunity.

Alternatively, if one DCI may schedule multiple PDSCHs and the DAI is information indicating the number of PDSCHs, the DAI may be information indicating the first PDSCH scheduled by this PDCCH or information indicating the last PDSCH scheduled by this PDCCH.

The second type of DAI may be referred to as a total DAI or a T-DAI (total-DAI), and is used to indicate information of a sum of the number of scheduled PDSCHs up to a PDCCH monitoring opportunity where a current PDCCH is located within a HARQ-ACK/NACK feedback bundling window; and/or the sum of the numbers of the PDCCHs transmitted until the PDCCH monitoring opportunity where the current PDCCH is positioned in the HARQ-ACK/NACK feedback binding window. That is, within the HARQ-ACK/NACK feedback bundling window, the count information of the scheduled PDSCH or the transmitted PDCCH up to the PDCCH monitoring opportunity where the current PDCCH is located.

Optionally, when the user is configured to operate in a multi-carrier state, or configured to be able to receive downlink data on multiple bandwidth portions BWP (bandwidth part) or sub-bands (e.g., LBT sub-band) simultaneously, the sum of the numbers of scheduled PDSCHs up to the PDCCH monitoring opportunity where the current PDCCH is located is determined by the sum of the numbers of all carriers transmitting the PDCCH, BWPs and/or PDSCHs scheduled by the PDCCH in the sub-bands up to the PDCCH monitoring opportunity.

Optionally, when the user is configured to operate in a multi-carrier state, or configured to be able to receive downlink data on multiple bandwidth portions BWPs or sub-bands (e.g., LBT sub-bands) simultaneously, the sum of the numbers of PDCCHs transmitted until the PDCCH monitoring opportunity where the current PDCCH is located is determined by the sum of all carriers transmitting PDCCHs, BWPs, and/or all PDCCH numbers in sub-bands within the PDCCH monitoring opportunity until the PDCCH monitoring opportunity.

The third kind of DAI can also be called total DAI or T-DAI and is used for indicating the information of the sum of the PDCCH numbers corresponding to the HARQ-ACK/NACK fed back on the PUSCH; and/or the sum of the number of PDSCHs corresponding to the HARQ-ACK/NACK fed back on the PUSCH.

Alternatively, in order to reduce the number of DAI bits, a larger actual value range of DAI can be represented by using limited DAI bits in a modulo manner. For example, 2-bit DAI, if T-DAI is 9, then modulo 4 operation is performed, which is 1.

Optionally, in order to reduce the number of bits of the DAI, the actual value of the DAI may also be represented by a coarser granularity. The relationship between the value of the DAI bit and the actual value of the DAI is, for example: the value of the DAI bit is x the granularity of the DAI. For example, if the DAI granularity is 4, then a 2-bit DAI represents 4, 8, 12, 16, respectively. This approach may be used in conjunction with the modulo approach. Thus, the actual DAI may range from 4, 8, 12, 16, 20 ….

It should be noted that the above-mentioned DAI counting is performed for each PDCCH and/or PDSCH feeding back HARQ-ACK/NACK in the same uplink time unit.

If the PDSCHs need to be grouped, the counting of the DAIs is carried out on each PDCCH and/or PDSCH in the same PDSCH group which feeds back the HARQ-ACK/NACK in the same uplink time unit. In case that a plurality of PDSCHs scheduled by one PDCCH belong to one or more PDSCH groups, the DAI may include one or more DAI bit fields, each corresponding to DAI information of one PDSCH group, respectively. With respect to the grouping of PDSCH, it will be further described below.

Optionally, in the case of grouping the PDSCH, multiple sets of first class DAI and second class DAI may be included in the DCI of the PDCCH, which respectively represent PDCCH and/or PDSCH count within each PDSCH set. For example, the base station configures 2 PDSCH groups, where PDSCH group 1 includes PDSCH transmitted with granularity based on transport block tb (transport block), and PDSCH group 2 includes PDSCH transmitted with granularity based on code block group CBG. If one DCI can schedule multiple PDSCHs and the transmission granularity of each PDSCH can be different, two groups of first class DAI and second class DAI are included in the DCI to respectively indicate the DAI information of each PDSCH in the corresponding PDSCH group. For example, one DCI schedules 4 PDSCHs (PDSCH 1, PDSCH2, PDSCH3 and PDSCH 4), where PDSCH1, PDSCH2 and PDSCH3 belong to PDSCH group 1 and PDSCH4 belongs to group 2, then the first group T-DAI ═ 3 indicates that PDSCH group 1 has 3 PDSCHs, and the second group T-DAI ═ 1 indicates that PDSCH group 2 has 1 PDSCH. If one DCI can only schedule PDSCH belonging to one PDSCH group, the DCI only needs to include one group of first class DAI and second class DAI, which represents the DAI count in the PDSCH group.

The HARQ-ACK/NACK feedback bundling window is determined by the set of all downlink time units and/or the set of all carriers which can simultaneously feed back the HARQ-ACK/NACK in the same uplink time unit. The uplink/downlink time unit may be one or more slots, mini-slots, sub-slots, or OFDM symbols.

According to one embodiment, before the terminal 10 transmits the hybrid automatic repeat request acknowledgement HARQ-ACK/NACK codebook for the PDSCH to the base station 20, the terminal 10 may determine an uplink time unit for feeding back the HARQ-ACK/NACK of the PDSCH from the PDCCH and the PDSCH received from the base station 20 and transmit the HARQ-ACK/NACK codebook in the uplink time unit.

The uplink time unit for transmitting the HARQ-ACK/NACK codebook is determined by, for example, HARQ-ACK/NACK timing indicated by the PDCCH. Alternatively, the HARQ-ACK/NACK timing for determining the uplink time unit for transmitting the HARQ-ACK/NACK codebook may be determined by a higher layer signaling configuration and/or by a predefined rule, e.g., may be determined according to a minimum delay for the UE to process the PDSCH.

Optionally, HARQ-ACK/NACK of each PDSCH scheduled by one PDCCH corresponds to the same uplink time unit. Optionally, HARQ-ACK/NACK of each PDSCH scheduled by one PDCCH corresponds to the same or different uplink time units. The maximum number of PDSCHs that can be scheduled by one PDCCH described below is limited to the maximum number of PDSCHs that can be scheduled to transmit HARQ-ACK/NACK in the same uplink time unit. For example, one PDCCH can schedule 4 PDSCHs at most, but if the base station configures HARQ-ACK/NACK of the 4 PDSCHs to belong to different PUCCHs, when calculating HARQ-ACK/NACK feedback as follows, 1 PDSCH can be scheduled for calculation at most according to one PDCCH. For another example, one PDCCH can schedule 4 PDSCHs at most, and the 4 PDSCHs feed back HARQ-ACK/NACK in the same PUCCH, and when calculating HARQ-ACK/NACK feedback as follows, 4 PDSCHs can be scheduled for calculation according to one PDCCH at most.

The HARQ-ACK/NACK feedback bundling window can be determined by the set of all downlink time units and/or the set of all carriers which can simultaneously feed back the HARQ-ACK/NACK in the same uplink time unit. The uplink/downlink time unit may be one or more slots, mini-slots, sub-slots, or OFDM symbols.

According to one embodiment, transmitting the HARQ-ACK/NACK codebook in an uplink time unit includes: grouping PDSCHs which are to feed back HARQ-ACK/NACK in the uplink time unit; and determining a HARQ-ACK/NACK codebook for each PDSCH group.

For example, the PDSCHs to which HARQ-ACK/NACK is to be fed back in uplink time units may be grouped according to a DCI format in which each PDSCH is scheduled, the number of PDSCHs indicated in the DCI, the number of HARQ-ACK/NACK bits corresponding to a PDSCH scheduled by one PDCCH, the transmission granularity of each scheduled PDSCH, and/or the transmission granularity of a reference PDSCH. Determining the HARQ-ACK/NACK codebook for each PDSCH group may include: and determining the HARQ-ACK/NACK codebook of each PDSCH group according to the DAI in the PDSCH group.

For grouping the PDSCHs according to the DCI format for scheduling each PDSCH, the base station configures or predefines rules and determines the corresponding relation between the DCI format and the PDSCH grouping. Assuming that a DCI format in which multiple PDSCHs can be scheduled is DCI format a, a DCI format in which only a single PDSCH can be scheduled is DCI format B. The plurality of PDSCHs scheduled by DCI format a correspond to different transport blocks, TBs. Then, the PDSCH scheduled by DCI format a and the PDSCH scheduled by DCI format B belong to different PDSCH groups.

Optionally, if one UE is configured with multiple DCI formats, determining a corresponding relationship between each DCI format and a PDSCH packet according to a base station configuration or a predefined rule. For example, the UE is configured with DCI format C of fallback mode, DCI format B of only a single PDSCH can be scheduled, and DCI format of multiple PDSCHs can be scheduled as DCI format a. And classifying the PDSCH scheduled by the DCI format C and the DCI format B into a PDSCH group 1, and classifying the PDSCH scheduled by the DCI format A into a PDSCH group 2.

For grouping PDSCH according to the number of PDSCH indicated in DCI scheduling each PDSCH, it is assumed that the PDSCH number threshold Th1 is predefined or configured by the base station. If the number X of the PDSCHs actually scheduled by one PDCCH is larger than a threshold Th1, the X PDSCHs belong to a PDSCH group i, and if X is smaller than or equal to the threshold Th1, the X PDSCHs belong to a PDSCH group j, wherein i is not equal to j.

For example, if Th1 is 1, PDCCH1 schedules 4 PDSCHs (PDSCH 1 to PDSCH4, respectively), and PDCCH2 schedules 1 PDSCH (PDSCH 5), PDSCH1 to PDSCH4 and PDSCH5 belong to different PDSCH groups. In this example, the DCI formats of PDCCH1 and PDCCH2 may be the same or different. For example, the DCI formats of PDCCH1 and PDCCH2 may both be DCI format a, or the DCI formats may be different, one being DCI format a and the other being DCI format B.

For determining a packet of a PDSCH according to the number of HARQ-ACK/NACK bits corresponding to a PDSCH scheduled by one PDCCH, it is assumed that the threshold Th2 of the number of HARQ-ACK/NACK bits is predefined or configured by the base station. If the sum of the HARQ-ACK/NACK bit numbers corresponding to all X PDSCHs scheduled by one PDCCH is larger than Th2, the X PDSCHs belong to a PDSCH group i, if X is smaller than or equal to a threshold Th2, the X PDSCH belongs to a PDSCH group j, wherein i is not equal to j.

For example, if Th2 is 4 bits, PDCCH1 schedules 2 PDSCHs, PDSCH1 and PDSCH2 respectively. Wherein, PDSCH1 is TB-based transmission, PDSCH2 is CBG-based transmission, and 2 CBGs are actually scheduled; 1 PDSCH3 is scheduled by PDCCH2, the PDSCH3 is based on the transmission of CBG of the code block group, and 8 CBG is actually scheduled; PDCCH3 schedules 2 PDSCHs, which are PDSCH4 and PDSCH5, respectively, PDSCH4 is based on CBG transmission of coded block groups, actually schedules 4 CBGs, PDSCH5 is based on CBG transmission of coded block groups, actually schedules 4 CBGs, then the total number of bits of PDSCH 1/2 does not exceed 4 bits, and belongs to PDSCH group 1; the total number of bits of PDSCH3 and PDSCH 4/5 exceeds 4 bits, and belongs to PDSCH group 2.

For determining the grouping of PDSCH according to the granularity of PDSCH transmission and/or HARQ-ACK/NACK feedback of PDSCH scheduled by one PDCCH, the grouping of PDSCH is determined according to whether this PDSCH is based on CBG or transport block TB, assuming that the UE is configured to operate in a scheduling and HARQ-ACK/NACK feedback mode with granularity based on coding block group CBG on at least one carrier.

Optionally, if one PDCCH can schedule multiple PDSCHs and the transmission granularity of each PDSCH scheduled by the PDCCH is the same, the PDSCH packets of all PDSCHs scheduled by the PDCCH can be determined according to the transmission granularity, and all PDSCHs belong to the same PDSCH packet.

Alternatively, if one PDCCH may schedule a plurality of PDSCHs, and the transmission granularity of each PDSCH scheduled by this PDCCH may be different, the PDSCH packets of each PDSCH may be determined according to the transmission granularity of each PDSCH, and each PDSCH may belong to different PDSCH packets.

Optionally, if one PDCCH can schedule multiple PDSCHs, and the transmission granularity of each PDSCH scheduled by the PDCCH may be different, determining PDSCH packets of all PDSCHs scheduled by the PDCCH according to the transmission granularity of the reference PDSCH, where all PDSCHs belong to the same PDSCH packet. That is, even if the transmission granularity of each PDSCH is different, all PDSCHs are classified as belonging to the same PDSCH packet, and a specific packet is determined according to the reference PDSCH packet. The reference PDSCH is predefined or determined according to predefined rules or semi-statically configured. Alternatively, the transmission granularity of the reference PDSCH is predefined, or determined according to predefined rules, or semi-statically configured. For example, if one PDCCH schedules 2 PDSCHs, one is based on TB transmission and one is based on CBG transmission, the 2 PDSCHs may belong to the same PDSCH group; when the transmission granularity of the reference PDSCH is CBG, the 2 PDSCHs all belong to a PDSCH group transmitted by CBG.

Determining the HARQ-ACK/NACK codebook for each PDSCH group according to the DAI within the PDSCH group may include: and determining the HARQ-ACK/NACK codebook of the PDSCH group according to the DAI in the PDSCH group and the HARQ-ACK/NACK bit number corresponding to each PDSCH in the PDSCH group. Specifically, the HARQ-ACK/NACK codebook for the PDSCH group may be determined in one of the following ways:

the first method is as follows: at one endNumber N of HARQ-ACK/NACK bits per PDSCH in each PDSCH group_{max_p}Is predefined, or base station configured, and schedulable by a PDCCH for the maximum number N of PDSCHs belonging to this PDSCH group_{max_pdsch}Is predefined or base station configured. If the DAI counts the PDCCHs, the number of HARQ-ACK/NACK bits corresponding to one PDCCH is N_t＝N_{max_p}×N_{max_pdsch}. Determining the total bit number of the HARQ-ACK/NACK codebook to be M multiplied by N according to the actual value M of the DAI in the PDSCH group_t＝M×N_{max_p}×N_{max_pdsch}. Or, if the DAI counts the PDSCHs, the number of HARQ-ACK/NACK bits N corresponding to one PDSCH_t＝N_{max_p}. When the value M of the DAI is the information of the last PDSCH in the plurality of PDSCHs scheduled by the DCI, determining the total bit number of the HARQ-ACK/NACK codebook to be M multiplied by N according to the actual value M of the DAI in the PDSCH group_t＝M×N_{max_p}. Optionally, if the DAI counts the PDSCHs and the value M of the DAI is the information of the first PDSCH of the N PDSCHs scheduled by the DCI, determining the total bit number of the HARQ-ACK/NACK codebook to be (M + N-1) × N according to the actual value M of the DAI in the PDSCH group_t＝(M+n-1)×N_{max_p}。

The second method comprises the following steps: in one PDSCH group, the number N of HARQ-ACK/NACK bits corresponding to one PDCCH_tIs predefined or base station configured. If the DAI counts the PDCCH, determining the total bit number of the HARQ-ACK/NACK codebook to be M multiplied by N according to the actual value M of the DAI in the PDSCH group_t. Optionally, the base station needs to ensure the number N of HARQ-ACK/NACK bits corresponding to one PDCCH during scheduling_tNot less than the sum of the number of HARQ-ACK/NACK bits of the respective PDSCHs actually scheduled by this PDCCH,

wherein Ni is the HARQ-ACK/NACK bit number of the ith PDSCH. For example, if the UE is configured to be dynamically operable in CBG or TB based transmissions, Ni for each PDSCH may be different.

Alternatively, if the UE is configured to transmit a maximum of L TBs in at least one frequency domain or time unit, H of one PDSCHARQ-ACK/NACK bit number N_{max_p}Determined by L and the number of HARQ-ACK/NACK bits per TB. For example, if configured for CBG-based transmission, the number of HARQ-ACK/NACK bits for one TB is N_{max_cbg}. The number of HARQ-ACK/NACK bits of one TB is 1 if configured for TB-based transmission.

The HARQ-ACK/NACK codebook for transmitting PDSCH in the uplink time unit further includes: and connecting the HARQ-ACK/NACK codebooks of all the groups according to a set sequence to form a HARQ-ACK/NACK codebook, and sending corresponding HARQ-ACK/NACK information through a PUCCH or PUSCH. Optionally, the HARQ-ACK/NACK codebook for transmitting PDSCH in uplink time unit includes: and respectively transmitting the HARQ-ACK/NACK information corresponding to the HARQ-ACK/NACK codebook of each group through the PUCCH or PUSCH.

The above-described steps, DAI, may be combined according to the PDSCH or PDCCH count, the PDSCH grouping manner, and various manners of determining the HARQ-ACK/NACK codebook for each PDSCH grouping according to the DAI within the PDSCH group to obtain different implementation manners of determining the HARQ-ACK/NACK codebook. Several specific examples are given below, but not limited thereto.

Example one: and determining the grouping of the PDSCHs according to the number of the PDSCHs indicated in the DCI for scheduling each PDSCH. And if the number of PDSCHs indicated in the DCI of one PDCCH is 1, the PDCCH is set as 1, and if the number of PDSCHs indicated in the DCI of one PDCCH is more than 1, the PDCCH is set as 2. In

PDSCH group

1, 1 PDSCH actually scheduled by one PDCCH is assumed, and each PDSCH corresponds to 1-bit HARQ-ACK/NACK. In PDSCH group 2, the number of HARQ-ACK/NACK bits N corresponding to one PDCCH _t4, the maximum number of PDSCHs that can be scheduled by one PDCCH, X, is 4, and each PDSCH corresponds to 1-bit HARQ-ACK/NACK. And if the number of actually scheduled PDSCHs of one PDCCH is less than 4, transmitting occupied bits until the total number of HARQ-ACK/NACK bits corresponding to the PDCCH is 4. The DCI of the PDCCH for scheduling the PDSCH comprises a first class DAI and a second class DAI which respectively represent the sum of the number of PDCCHs transmitted to the current PDCCH and the sum of the number of PDCCHs transmitted to the PDCCH monitoring opportunity where the current PDCCH is located in a HARQ-ACK/NACK feedback binding window. DAIs of the first and second typesCounting within two PDSCH groups. Then, for PDSCH group 1, if the actual value of the second type DAI of the last PDSCH within the bundling window is M1, the total number of bits of the HARQ-ACK/NACK codebook for PDSCH group 1 is M1. For PDSCH group 2, if the actual value of the second type DAI of the last PDSCH within the bundling window is M2, the total number of bits of the HARQ-ACK/NACK codebook for PDSCH group 2 is M2 × 4. The HARQ-ACK/NACK codebooks of the PDSCH group 1 and the PDSCH group 2 are concatenated to have M1+ M2 x 4 bits HARQ-ACK/NACK.

Fig. 2 illustrates an example of a HARQ-ACK/NACK feedback bundling window and a HARQ-ACK/NACK codebook according to example one. As shown in fig. 2, the base station configures 3 carriers for the UE. In the HARQ-ACK/NACK binding window, in the first PDCCH monitoring opportunity, the UE monitors PDCCHs on 3 carriers. Wherein the PDCCH of carrier 1 schedules PDSCH1, PDSCH1 belonging to PDSCH group 1. C-DAI ═ 1 indicates that this PDCCH is the first PDCCH belonging to PDSCH group 1 in this PDCCH monitoring opportunity, and T-DAI ═ 1 indicates that there are only 1 PDCCH in PDSCH group 1 in this PDCCH monitoring opportunity. And dispatching PDSCHs 2-5 by the PDCCH of the carrier 2, wherein the PDSCHs 2-5 belong to a PDSCH group 2. C-DAI ═ 1 indicates that this PDCCH is the first PDCCH belonging to PDSCH group 2 in this PDCCH monitoring opportunity, and T-DAI ═ 2 indicates that PDSCH group 2 has 2 PDCCHs in this PDCCH monitoring opportunity. PDSCHs 6-9 are scheduled by the PDCCH of the carrier 3, and the PDSCHs 6-9 belong to a PDSCH group 2. C-DAI ═ 2 indicates that this PDCCH is the second PDCCH belonging to PDSCH group 2 in this PDCCH monitoring opportunity, and T-DAI ═ 2 indicates that PDSCH group 2 has 2 PDCCHs in this PDCCH monitoring opportunity. Then, in the next PDCCH monitoring opportunity, the UE monitors the PDCCH on both 2 carriers (carrier 1 and carrier 3). PDSCHs 10-11 are scheduled by the PDCCH of the carrier 1, and the PDSCHs 10-11 belong to a PDSCH group 2. C-DAI ═ 3 indicates that this PDCCH is the third PDCCH belonging to PDSCH group 2 up to this PDCCH monitoring opportunity, and T-DAI ═ 4 indicates that there are 4 PDCCHs in PDSCH group 2 up to this PDCCH monitoring opportunity. PDSCHs 12-15 are scheduled by the PDCCH of the carrier 3, and the PDSCHs 12-15 belong to a PDSCH group 2. C-DAI ═ 4 indicates that this PDCCH is the fourth PDCCH belonging to PDSCH group 2 up to this PDCCH monitoring opportunity, and T-DAI ═ 4 indicates that there are 4 PDCCHs in PDSCH group 2 up to this PDCCH monitoring opportunity. Then, in the next PDCCH monitoring opportunity, the UE monitors the PDCCH on 1 carrier (carrier 2). Where the PDCCH for carrier 1 schedules PDSCH 16, PDSCH 16 belongs to PDSCH group 1. C-DAI ═ 2 indicates that this PDCCH is the second PDCCH belonging to PDSCH group 1 up to this PDCCH monitoring opportunity, and T-DAI ═ 2 indicates that there are 2 PDCCHs in PDSCH group 1 up to this PDCCH monitoring opportunity. Then, when the UE generates the codebook, the HARQ-ACK/NACK codebook 1 of the PDSCH group 1 contains 2-bit HARQ-ACK/NACK, which are HARQ-ACK/NACK of the PDSCH1 and the PDSCH 16, respectively, and the HARQ-ACK/NACK codebook 2 of the PDSCH group 2 contains 16-bit HARQ-ACK/NACK, which are HARQ-ACK/NACK of the PDSCHs 2 to 15, respectively, and 2-bit HARQ-ACK/NACK bits for occupancy. The 2-bit occupied bits are located after the HARQ-ACK/NACK of the

PDSCHs

10 and 11, so that the number of HARQ-ACK/NACK bits corresponding to one PDCCH is 4.

Example two: and determining the grouping of the PDSCH according to the granularity of PDSCH transmission scheduled by one PDCCH and/or HARQ-ACK/NACK feedback of the PDSCH. Assuming that the base station is configured with only TB-based transmission, all PDSCHs belong to the same group. The DCI of the PDCCH for scheduling the PDSCH comprises a first class DAI and a second class DAI which respectively represent the sum of the number of PDSCHs transmitted to the current PDCCH in a HARQ-ACK/NACK feedback binding window and the sum of the number of PDSCHs transmitted to the PDCCH monitoring opportunity where the current PDCCH is located. Then, if the actual value of the second type DAI of the last PDSCH in the bundling window is M1, the total number of bits of the HARQ-ACK/NACK codebook is M1 (assuming that the base station configures one PDSCH to transmit only one TB).

Fig. 3 shows an example of a HARQ-ACK/NACK feedback bundling window and a HARQ-ACK/NACK codebook according to example two. As shown in fig. 3, the base station configures 3 carriers for the UE. In the HARQ-ACK/NACK binding window, in the first PDCCH monitoring opportunity, the UE monitors PDCCHs on 3 carriers. Wherein, the PDCCH of carrier 1 schedules PDSCH 1. C-DAI ═ 1 indicates that this PDSCH is the first PDSCH scheduled in this PDCCH monitoring opportunity, and T-DAI ═ 1 indicates that the number of all PDSCHs scheduled in this PDCCH monitoring opportunity is 9. And dispatching PDSCHs 2-5 by the PDCCH of the carrier 2. C-DAI ═ 2, which indicates that this PDSCH is the second PDSCH scheduled in this PDCCH monitoring opportunity, and T-DAI ═ 9, which indicates that the number of all PDSCHs scheduled in this PDCCH monitoring opportunity is 9. And scheduling PDSCHs 6-9 by the PDCCH of the carrier 3. C-DAI ═ 6, which indicates that this PDSCH is the 6 th PDSCH scheduled in this PDCCH monitoring opportunity, and T-DAI ═ 9, which indicates that the number of all PDSCHs scheduled in this PDCCH monitoring opportunity is 9. Then, in the next PDCCH monitoring opportunity, the UE monitors the PDCCH on both 2 carriers (carrier 1 and carrier 3). And scheduling PDSCHs 10-11 by the PDCCH of the carrier 1. C-DAI ═ 10 indicates that this PDSCH is the 10 th PDSCH scheduled until this PDCCH monitoring opportunity, and T-DAI ═ 15 indicates that the number of all PDSCHs scheduled until this PDCCH monitoring opportunity is 15. And scheduling PDSCHs 12-15 by the PDCCH of the carrier 3. C-DAI ═ 4 indicates that this PDSCH is the 12 th PDSCH scheduled until this PDCCH monitoring opportunity, and T-DAI ═ 15 indicates that the number of all PDSCHs scheduled until this PDCCH monitoring opportunity is 15. Then, in the next PDCCH monitoring opportunity, the UE monitors the PDCCH on 1 carrier (carrier 2). Where the PDCCH for carrier 1 schedules PDSCH 16. C-DAI-16 indicates that this PDSCH is the 16 th PDSCH scheduled until this PDCCH monitoring opportunity, and T-DAI-16 indicates that the number of all PDSCHs scheduled until this PDCCH monitoring opportunity is 16. Then, when the UE generates the codebook, only one HARQ-ACK/NACK codebook is generated, which comprises 16-bit HARQ-ACK/NACK which are respectively HARQ-ACK/NACK of PDSCHs 1-16. The values of the actual DAI are given in the figures. The method of example two saves more overhead for HARQ-ACK/NACK than the method of example one, but to achieve the same robustness, e.g., to ensure that the HARQ-ACK/NACK codebook is not affected in case a certain number of PDCCHs are lost, the number of bits of DAI required for example two is more.

Example three: and determining the grouping of the PDSCH according to the granularity of PDSCH transmission scheduled by one PDCCH and/or HARQ-ACK/NACK feedback of the PDSCH. Assuming that the base station is configured with only TB-based transmission, all PDSCHs belong to the same group. The DCI of the PDCCH for scheduling the PDSCH comprises a first class DAI and a second class DAI which respectively represent the sum of the number of PDCCHs transmitted to the current PDCCH and the sum of the number of PDCCHs transmitted to the PDCCH monitoring opportunity where the current PDCCH is located in a HARQ-ACK/NACK feedback binding window. Suppose HARQ-ACK/NACK bit number N corresponding to one PDCCH_tConfigured by the base station, N _t4, the maximum number of PDSCHs that can be scheduled by one PDCCH, X, is 4, and each PDSCH corresponds to 1-bit HARQ-ACK/NACK. If one isAnd if the number of actually scheduled PDSCHs of the PDCCH is less than 4, transmitting occupied bits until the total number of HARQ-ACK/NACK bits corresponding to the PDCCH is 4. Then, if the actual value of the second type DAI of the last PDSCH within the bundling window is M1, the total number of bits of the HARQ-ACK/NACK codebook is M1 × 4.

Fig. 4 shows an example of a HARQ-ACK/NACK feedback bundling window and a HARQ-ACK/NACK codebook according to example three. As shown in fig. 4, the base station configures 3 carriers for the UE. In the HARQ-ACK/NACK binding window, in the first PDCCH monitoring opportunity, the UE monitors PDCCHs on 3 carriers. Where the PDCCH for carrier 1 schedules PDSCH 1. C-DAI ═ 1 indicates that this PDCCH is the first PDCCH scheduled in this PDCCH monitoring opportunity, and T-DAI ═ 3 indicates that the number of all PDCCHs in this PDCCH monitoring opportunity is 3. And dispatching PDSCHs 2-5 by the PDCCH of the carrier 2. C-DAI ═ 2 indicates that this PDCCH is the second PDCCH in this PDCCH monitoring opportunity, and T-DAI ═ 3 indicates that the number of all PDCCHs in this PDCCH monitoring opportunity is 3. And scheduling PDSCHs 6-9 by the PDCCH of the carrier 3. C-DAI ═ 3 indicates that this PDCCH is the 3 rd PDCCH in this PDCCH monitoring opportunity, and T-DAI ═ 3 indicates that the number of all PDCCHs in this PDCCH monitoring opportunity is 3. Then, in the next PDCCH monitoring opportunity, the UE monitors the PDCCH on both 2 carriers (carrier 1 and carrier 3). And scheduling PDSCHs 10-11 by the PDCCH of the carrier 1. C-DAI ═ 4 indicates that this PDCCH is the 4 th PDCCH up to this PDCCH monitoring opportunity, and T-DAI ═ 5 indicates that the number of all PDCCHs up to this PDCCH monitoring opportunity is 5. And scheduling PDSCHs 12-15 by the PDCCH of the carrier 3. C-DAI ═ 5 indicates that this PDCCH is the 5 th PDCCH up to this PDCCH monitoring opportunity, and T-DAI ═ 5 indicates that the number of all PDCCHs up to this PDCCH monitoring opportunity is 5. Then, in the next PDCCH monitoring opportunity, the UE monitors the PDCCH on 1 carrier (carrier 2). Where the PDCCH for carrier 2 schedules PDSCH 16. C-DAI ═ 6 indicates that this PDCCH is the 6 th PDCCH up to this PDCCH monitoring opportunity, and T-DAI ═ 6 indicates that the number of all PDCCHs up to this PDCCH monitoring opportunity is 6. Then, when the UE generates the codebook, only one HARQ-ACK/NACK codebook is generated, which comprises 24-bit HARQ-ACK/NACK which are respectively HARQ-ACK/NACK of PDSCHs 1-16. Each PDCCH corresponds to 4-bit HARQ-ACK/NACK, 4 bits corresponding to the PDCCH for scheduling the PDSCH1 are HARQ-ACK/NACK of the PDSCH1 and 3-bit space occupying bits, 4-bit HARQ-ACK/NACK corresponding to the PDCCHs for scheduling the

PDSCHs

10 and 11 are HARQ-ACK/NACK of the

PDSCHs

10 and 11 and 2-bit space occupying bits, and 4-bit HARQ-ACK/NACK corresponding to the PDCCH for scheduling the PDSCH 16 is HARQ-ACK/NACK of the PDSCH 16 and 3-bit space occupying bits. The method of example three saves more overhead of DAI than the method of example two, but HARQ-ACK/NACK overhead increases significantly. The method of example three is simpler and more robust than the method of example one, but the HARQ-ACK/NACK overhead is significantly increased.

Example four: and determining the grouping of the PDSCH according to the granularity of PDSCH transmission scheduled by one PDCCH and/or HARQ-ACK/NACK feedback of the PDSCH. Assuming that the UE is configured to operate in a scheduling and HARQ-ACK/NACK feedback mode with coding block group CBG based granularity on at least one carrier, the grouping of PDSCH is determined according to whether this PDSCH is based on CBG or transport block TB. PDSCH group 1 if the transmission granularity of PDSCH is TB, and PDSCH group 2 if the transmission granularity of PDSCH is CBG. It is assumed that one PDCCH can schedule multiple PDSCHs, and the transmission granularity of each PDSCH scheduled by the PDCCH is the same and is based on TB transmission. Then, all PDSCHs of this type belong to PDSCH group 1. The DCI of the PDCCH for scheduling the PDSCH comprises a first class DAI and a second class DAI which respectively represent the sum of the number of PDSCHs sent to the current PDCCH in a HARQ-ACK/NACK feedback binding window and the sum of the number of PDSCHs sent to the PDCCH monitoring opportunity where the current PDCCH is located. The first and second types of DAIs are counted within two PDSCH groups, respectively. In PDSCH group 1, the number of HARQ-ACK/NACK bits for each PDSCH is 1 bit (assuming that the base station is configured to transmit only one TB for one PDSCH). In PDSCH group 2, the number of HARQ-ACK/NACK bits corresponding to each PDSCH is N_{max_cbg}(maximum number of CBGs that a TB can partition). Then, if the actual value of the DAI of the second type of the last PDSCH within the bundling window is M2, the total number of bits of the HARQ-ACK/NACK codebook is M2 × N_{max_cbg}(assume that the base station is configured with one PDSCH to transmit only one TB).

Example five: and determining the grouping of the PDSCH according to the granularity of PDSCH transmission scheduled by one PDCCH and/or HARQ-ACK/NACK feedback of the PDSCH.Assuming that the UE is configured to operate in a scheduling and HARQ-ACK/NACK feedback mode with coding block group CBG based granularity on at least one carrier, the grouping of PDSCH is determined according to whether this PDSCH is based on CBG or transport block TB. PDSCH group 1 if the transmission granularity of PDSCH is TB, and PDSCH group 2 if the transmission granularity of PDSCH is CBG. It is assumed that one PDCCH can schedule multiple PDSCHs, and the transmission granularity of each PDSCH scheduled by the PDCCH is the same and is based on TB transmission. Then, all PDSCHs of this type belong to PDSCH group 1. The DCI of the PDCCH for scheduling the PDSCH comprises a first class DAI and a second class DAI which respectively represent the sum of the number of PDCCHs transmitted to the current PDCCH and the sum of the number of PDCCHs transmitted to the PDCCH monitoring opportunity where the current PDCCH is located in an HARQ-ACK/NACK feedback binding window. The first and second types of DAIs are counted within two PDSCH groups, respectively. In PDSCH group 1, the number of HARQ-ACK/NACK bits N corresponding to each PDCCH_tThe maximum number of PDSCHs X that can be scheduled for one PDCCH is 4, and each PDSCH corresponds to 1-bit HARQ-ACK/NACK. Then, if the actual value of the second type DAI of the last PDSCH in the bundling window is M1, the total number of bits of the HARQ-ACK/NACK codebook is M1 × 4 (assuming that the base station is configured with only one TB transmitted by one PDSCH). For a PDCCH with the scheduled PDSCH number less than 4, for example, a PDCCH with only one PDSCH scheduled, a PDCCH of a DCI operating in a fallback mode, and the like, need to be occupied by occupied bits until 4-bit HARQ-ACK/NACK is satisfied. In PDSCH group 2, the number of HARQ-ACK/NACK bits N corresponding to each PDCCH_tIs N_{max_cbg}(maximum number of CBGs that a TB can partition). Then, if the actual value of the DAI of the second type of the last PDSCH within the bundling window is M2, the total number of bits of the HARQ-ACK/NACK codebook is M2 × N_{max_cbg}(assume that the base station is configured with one PDSCH to transmit only one TB).

In this case, a special implementation is to bundle the HARQ-ACK/NACKs of multiple PDSCHs scheduled by one PDCCH, i.e. to and all these PDSCHs' HARQ-ACK/NACKs, resulting in a 1-bit HARQ-ACK/NACK. Then, in PDSCH group 1, the number of HARQ-ACK/NACK bits N corresponding to each PDCCH_tAssuming base station configuration for 1 bitOnly one TB can be transmitted by one PDSCH).

Example six: and determining the grouping of the PDSCH according to the granularity of PDSCH transmission scheduled by one PDCCH and/or HARQ-ACK/NACK feedback of the PDSCH. Assuming that the UE is configured to operate in a scheduling and HARQ-ACK/NACK feedback mode with coding block group CBG based granularity on at least one carrier, the grouping of PDSCH is determined according to whether this PDSCH is based on CBG or transport block TB. PDSCH group 1 if the transmission granularity of PDSCH is TB, and PDSCH group 2 if the transmission granularity of PDSCH is CBG. It is assumed that one PDCCH may schedule a plurality of PDSCHs, and transmission granularity of each PDSCH scheduled by this PDCCH may be different, and PDSCH packets of each PDSCH are determined according to the respective transmission granularity.

Optionally, in the DCI of the PDCCH for scheduling PDSCH, two groups of first class DAI and second class DAI may be included, which respectively represent PDSCH counts in the two PDSCH groups. In each DAI bit domain, the first type of DAI respectively represents the sum of the number of PDSCHs scheduled until the current PDCCH in the HARQ-ACK/NACK feedback binding window and the sum of the number of PDSCHs scheduled until the PDCCH monitoring opportunity where the current PDCCH is located. The first and second types of DAIs are counted within two PDSCH groups, respectively. If all PDSCHs belong to one PDSCH packet in one scheduling, the DAI bit field of another PDSCH packet may be set to a predefined value, for example, a special value or the same value as the DAI value in the last received PDCCH, or T-DAI is an actual value, C-DAI is a special value or the same value as the last DAI value or the same value as the next DAI value, or no value is defined but the UE does not determine the HARQ-ACK/NACK codebook according to this value.

In PDSCH group 1, if the actual value of the second type DAI of the last PDSCH in the bundling window is M1, the total number of bits of the HARQ-ACK/NACK codebook is M1 (assuming that the base station configures one PDSCH to transmit only one TB). Then, if the actual value of the second type DAI of the last PDSCH in the bundling window is M2, the total number of bits of the HARQ-ACK/NACK codebook is M2 (assuming that the base station configures one PDSCH to transmit only one TB).

FIG. 5 illustrates HARQ-ACK/NACK feedback bundling window and H according to example sixExample of an ARQ-ACK/NACK codebook. As shown in fig. 5, the base station configures 3 carriers for the UE. In the HARQ-ACK/NACK binding window, in the first PDCCH monitoring opportunity, the UE monitors PDCCHs on 3 carriers. Assuming that carrier 1 is configured to support only TBs for transmission granularity, 1-bit HARQ-ACK/NACK is fed back per PDSCH. Carrier 2 and carrier 3 are configured to be able to transmit with CBG as transmission granularity, each CBG-based PDSCH feedback N_{max_cbg}Each TB-based PDSCH feeds back 1-bit HARQ-ACK/NACK 2 bits. Where the PDCCH for carrier 1 schedules PDSCH1, belonging to PDSCH group 1. C-DAI ═ 1, which indicates that this PDSCH is the first PDSCH scheduled in this PDCCH monitoring opportunity, and T-DAI ═ 6, which indicates that the number of all PDSCHs in this PDCCH monitoring opportunity is 6. The PDCCH of the carrier 2 schedules PDSCHs 2-5, the

PDSCHs

2, 3 and 5 are TB-based transmission, and the PDSCH4 is CBG-based transmission, so the

PDSCHs

2, 3 and 5 belong to a PDSCH group 1, and the PDSCH4 belongs to a PDSCH group 2. Group 1 has C-DAI ═ 2 and T-DAI ═ 6, group 2 has C-DAI ═ 1 and T-DAI ═ 3. The PDCCH for carrier 3 schedules PDSCH 6-9 indicating that PDSCH6, 7 is CBG based transmission and

PDSCH

8, 9 is TB based transmission, then

PDSCH

8, 9 belongs to PDSCH group 1 and PDSCH6, 7 belongs to PDSCH group 2. Group 1 has C-DAI ═ 5 and T-DAI ═ 6, group 2 has C-DAI ═ 2 and T-DAI ═ 3. Then, in the next PDCCH monitoring opportunity, the UE monitors the PDCCH on 2 carriers (carrier 1, carrier 3). And scheduling PDSCHs 10-11 by the PDCCH of the carrier 1. Belonging to the PDSCH group 1, C-DAI ═ 7, and T-DAI ═ 11. And the PDCCH of the carrier 3 schedules the PDSCHs 12-15, indicates that the PDSCHs 12-14 are transmission based on TB and the PDSCH15 is transmission based on CBG, so that the PDSCHs 12-14 belong to a PDSCH group 1 and the PDSCH15 belongs to a PDSCH group 2. Group 1 has C-DAI ═ 9 and T-DAI ═ 11, group 2 has C-DAI ═ 4 and T-DAI ═ 4. Then, in the next PDCCH monitoring opportunity, the UE monitors the PDCCH on 1 carrier (carrier 2). Where the PDCCH for carrier 2 schedules PDSCH 16. The PDCCH supports scheduling of a maximum of 1 PDSCH, and only includes one DAI bit field indicating the DAI of the PDSCH group to which the PDCCH belongs. The base station indicates PDSCH 16 as CBG based transmission, then PDSCH 16 belongs to PDSCH group 2. C-DAI-5 and T-DAI-5. Then, the UE generates 2 HARQ-ACK/NACK codebooks when generating the codebooks, wherein codebook 1 comprises 11 HARQ-ACK/NACK of 11 PDSCHs in total, codebook 2 comprises 5 HARQ-ACK/NACK of PDSCHs in total comprising 10 bits. The total codebook length is 21 bits.

Example seven: and determining the grouping of the PDSCH according to the granularity of PDSCH transmission scheduled by one PDCCH and/or HARQ-ACK/NACK feedback of the PDSCH. Assuming that the UE is configured to operate in a scheduling and HARQ-ACK/NACK feedback mode with coding block group CBG based granularity on at least one carrier, the grouping of PDSCH is determined according to whether this PDSCH is based on CBG or transport block TB. PDSCH group 1 if the transmission granularity of PDSCH is TB, and PDSCH group 2 if the transmission granularity of PDSCH is CBG. It is assumed that one PDCCH may schedule a plurality of PDSCHs, and transmission granularity of each PDSCH scheduled by this PDCCH may be different, and PDSCH packets of each PDSCH are determined according to the respective transmission granularity.

Optionally, in the DCI of the PDCCH for scheduling the PDSCH, two groups of first class DAI and second class DAI may be included, which respectively represent PDCCH counts in the two PDSCH groups. In each DAI bit domain, the first type of DAI respectively represents the sum of the numbers of PDCCHs which are sent up to the current PDCCH in the HARQ-ACK/NACK feedback binding window and the sum of the numbers of PDCCHs which are sent up to the PDCCH monitoring opportunity where the current PDCCH is located. The first and second types of DAIs are counted within two PDSCH groups, respectively. If all the PDSCHs belong to one PDSCH group in one scheduling, the DAI bit field of the other PDSCH group can be set to a predefined value, or a value is not limited, but the UE does not determine the HARQ-ACK/NACK codebook according to the value.

In PDSCH group 1, the number of HARQ-ACK/NACK bits N corresponding to each PDCCH_tMaximum number N of PDSCHs based on TB Transmission that can be scheduled for one PDCCH_{tb_pdsch}Each PDSCH corresponds to 1-bit HARQ-ACK/NACK (assuming that the base station is configured with one PDSCH that can only transmit one TB). In PDSCH group 2, the number of HARQ-ACK/NACK bits N corresponding to each PDCCH_tMaximum number N of PDSCHs based on CBG Transmission schedulable by one PDCCH_{cbg_pdsch}Number of HARQ-ACK/NACK bits N with each PDSCH_{max_cbg}Determination, e.g. N_{cbg_pdsch}×N_{max_cbg}. Where each PDSCH corresponds to N_{max_cbg}Bit HARQ-ACK/NACK (assuming the base station is configured with one PDSCH transmitting only one TB). Alternatively, N_{tb_pdsch}Equal to the maximum number of PDSCHs that can be scheduled by one PDCCH. Alternatively, N_{tb_pdsch}And/or N_{cbg_pdsch}Either predefined or base station configured.

Fig. 6 illustrates an example of a HARQ-ACK/NACK feedback bundling window and a HARQ-ACK/NACK codebook according to example seven. As shown in fig. 6, the base station configures 3 carriers for the UE. The base station configures 4 as the maximum number of schedulable PDSCHs N of one PDCCH, wherein at most 2 PDSCHs can be transmitted based on CBG, and the number of PDSCHs transmitted based on TB is not limited. Then, N_{cbg_pdsch}＝2，N _{tb_pdsch}4. In the HARQ-ACK/NACK binding window, in the first PDCCH monitoring opportunity, the UE monitors PDCCHs on 3 carriers. Assuming that carrier 1 is configured to support only TBs for transmission granularity, 1-bit HARQ-ACK/NACK is fed back per PDSCH. Carrier 2 and carrier 3 are configured to be able to transmit with CBG as transmission granularity, each CBG-based PDSCH feedback N_{max_cbg}Each TB-based PDSCH feeds back 1-bit HARQ-ACK/NACK 2 bits. Where the PDCCH of carrier 1 schedules PDSCH1, belonging to PDSCH group 1, C-DAI ═ 1, indicating that this PDSCH is the first PDCCH in this PDCCH monitoring opportunity. T-DAI ═ 3 indicates that the number of all PDCCHs in this PDCCH monitoring opportunity is 3. The PDCCH of carrier 2 schedules PDSCHs 2-5 indicating that

PDSCHs

2, 3, 5 are TB-based transmissions and PDSCH4 is CBG-based transmissions, then

PDSCHs

2, 3, 5 belong to PDSCH group 1 and PDSCH4 belongs to PDSCH group 2. Group 1 has C-DAI ═ 2 and T-DAI ═ 3, group 2 has C-DAI ═ 1 and T-DAI ═ 2. The PDCCH of carrier 3 schedules PDSCHs 6-9 indicating that

PDSCHs

6, 7 are CBG based transmissions and

PDSCHs

8, 9 are TB based transmissions, then

PDSCHs

8, 9 belong to PDSCH group 1 and

PDSCHs

6, 7 belong to PDSCH group 2. Group 1 has C-DAI ═ 3, T-DAI ═ 3, group 2 has C-DAI ═ 2, and T-DAI ═ 2. Then, in the next PDCCH monitoring opportunity, the UE monitors the PDCCH on 2 carriers (carrier 1, carrier 3). And scheduling PDSCHs 10-11 by the PDCCH of the carrier 1. Belonging to the PDSCH group 1, C-DAI-4, T-DAI-5. And the PDCCH of the carrier 3 schedules PDSCHs 12-15, indicates that the PDSCHs 12-14 are transmission based on TB, and the PDSCH15 is transmission based on CBG, so that the PDSCHs 12-14 belong to a PDSCH group 1, and the PDSCH15 belongs to a PDSCH group 2. Group 1 has C-DAI ═ 5, T-DAI ═ 5, group 2 has C-DAI ═ 3, and T-DAI ═ 3. Then, in the next PDCCH monitoring opportunity, the UE is in 1PDCCH is monitored on carrier (carrier 2). Where the PDCCH for carrier 2 schedules PDSCH 16. The PDCCH supports scheduling of a maximum of 1 PDSCH, and only includes one DAI bit field indicating the DAI of the PDSCH group to which the PDCCH belongs. The base station indicates PDSCH 16 as CBG based transmission, then PDSCH 16 belongs to PDSCH group 2. C-DAI-4, T-DAI-4. Then, when generating the codebook, the UE generates 2 HARQ-ACK/NACK codebooks, where codebook 1 includes HARQ-ACK/NACK for 11 PDSCHs scheduled by 5 PDCCHs, each PDCCH corresponds to 4 bits and has 20 bits in total, codebook 2 includes HARQ-ACK/NACK for 4 PDSCHs scheduled by 4 PDCCHs, and each PDCCH corresponds to 2 × 2 ═ 4 bits and has 16 bits in total. The total codebook length is 36 bits. Example seven saves DAI overhead over example six, but UCI overhead increases. Since for each PDCCH the HARQ-ACK/NACK is generated according to the maximum number of PDSCHs that can be scheduled belonging to this PDSCH group.

When HARQ-ACK/NACK of PDSCHs of a plurality of carriers or HARQ-ACK/NACK of PDSCHs of a plurality of downlink time units are fed back in one uplink time unit, and the DCI formats for scheduling the PDSCHs or the number of the scheduled PDSCHs indicated by the DCI may be different, the problem that the size or the arrangement sequence of an HARQ-ACK/NACK codebook cannot be determined due to the fact that the number of the PDSCHs which are not determined when one or more PDSCHs (PDCCH) are missed by the UE can be avoided by using the scheme according to the embodiment.

According to one embodiment, the terminal 10 receiving the PDSCH from the base station 20 according to the received PDCCH further includes: receiving a demodulation reference signal (DMRS) of a PDSCH.

In this embodiment, the base station predefines a set of patterns for one or more sets of DMRS. The base station indicates the DMRS pattern adopted by one or one type of PDSCH, for example, through higher layer signaling configuration, or physical layer information indication, or system information.

For example, the base station may represent the pattern of the DMRS by configuring time-frequency resources in which the DMRS is located within one time window. The length of this time window and the start of the time window are configurable or predefined.

Optionally, the start of this time window is referenced to a predefined point in time, e.g. according to the start of a certain system frame/subframe/slot or a group of system frames/subframes/slots.

For example, one DMRS pattern configured by the base station includes period information, time offset information, and a time length, and is used to determine a time slot in which the DRMS is located. The base station also configures which symbols within these slots contain the DMRS.

In a specific implementation, DMRSs may not be included in time-frequency resources of the scheduled PDSCH, and the scheduled PDSCH relies on DMRSs outside the PDSCH time-frequency resources for channel estimation. For example, the base station schedules PDSCHs 1-4 through PDCCH1, occupies the 1 st to 7 th, 8 th to 14 th symbols of a time slot n and the 1 st to 7 th, 8 th to 14 th symbols of a time slot n +1, and schedules PDSCHs 5-8 through PDCCH2, occupies the 1 st to 7 th, 8 th to 14 th symbols of a time slot n +2 and the 1 st to 7 th, 8 th to 14 th symbols of a time slot n + 3. The base station indicates DMRS patterns which are 3 to 4 symbols of time slots n, n +2, n +4 and …. Then, DMRS is contained in the time-frequency resources of PDSCH1,3, and DMRS is not contained in the time-frequency resources of PDSCH2, 4. Or, the base station indicates the DMRS pattern as the 3 rd to 4 th symbols of the time slot n, n +4, n +8, …. Then, the time frequency resources of the PDSCH1 contain the DMRS, and the time frequency resources of the PDSCHs 2-4 do not contain the DMRS.

Optionally, the starting point of the time window is referred to a specific time point of the scheduled PDSCH, for example, the starting point of the time window is the starting point of the time of the first PDSCH, or the starting point of the time window is the starting point of the downlink time unit where the starting point of the time of the first PDSCH is located, for example, the starting point of the downlink time slot where the starting point of the time of the first PDSCH is located. As another example, the start of this time window is referenced to the start of time of each PDSCH that is scheduled.

Optionally, the base station configures the offset of the start of this time window from the start of the reference time.

For example, one DMRS pattern configured by the base station includes a symbol position index for determining which symbols include a DMRS from the first PDSCH. The DMRS pattern is assumed to be the 3 rd symbol of the first slot and the 3 rd symbol of the third slot. The base station schedules 4 PDSCHs through one DCI, each PDSCH occupying 1 time slot. Then the first slot of the DMRS pattern is the slot where the start of PDSCH1 is located. Therefore, the 3 rd symbol in PDSCH1,3 contains DMRS, and PDSCH2,4 does not contain DMRS.

For example, one DMRS pattern configured by the base station includes a symbol position index for determining which symbols include a DMRS from each PDSCH. The DMRS pattern is assumed to be the 1 st and 6 th symbols of one PDSCH. The base station schedules 4 PDSCHs through one DCI, each PDSCH occupies 1 time slot, and for each PDSCH, DMRS is included in the 1 st and 6 th symbols of each PDSCH.

For another example, one DMRS pattern configured by the base station includes a symbol position index and a time offset, and is used to determine which symbols start with the first symbol relative to the starting point of the PDSCH and which symbols follow the first symbol contain DMRS.

Optionally, the base station configures whether there is an additional DMRS. If the additional DMRS exists, determining the position of the additional DMRS according to the time domain information of each scheduled PDSCH separately; or, the position of the additional DMRS is determined in common according to time domain information of all PDSCHs scheduled by the DCI of one PDCCH.

For example, when the PDSCH length is less than or equal to the threshold Th _ p, there is only the first set of DMRSs. When the PDSCH length is greater than a threshold Th _ p, there is a second set of DMRSs that are offset back by X _ p symbols relative to the symbol positions of the first set of DMRSs. Let Th _ p be 10 symbols. The base station schedules 4 PDSCHs through one DCI, each PDSCH is 7 symbols long, and X _ p is 8 symbols. Then, if the location of the additional DMRS is determined separately from the time domain information of each PDSCH scheduled, because each PDSCH is 7 symbols in length smaller than Th _ p, only the first set of DMRS is located in each PDSCH at the first symbol of each PDSCH. If the time domain information of all PDSCHs scheduled according to the DCI of one PDCCH collectively determines the location of additional DMRSs, since the total length of 4 PDSCHs is 28 symbols, which is greater than Th _ p, the 1 st symbol contains the first set of DMRS and the 9 Th symbol contains the second set of DMRS within the 28 symbols of the 4 PDSCHs. Namely, DMRSs are contained in PDSCH1 and PDSCH2, and DMRSs are not contained in PDSCH3 and PDSCH 4.

Optionally, the time length of the time window is Y milliseconds, or Y time slots. Optionally, the partial DMRS pattern may be predefined.

Optionally, the correspondence of PDSCH type to DMRS pattern is predefined or base station configured. For example, DMRS patterns corresponding to multiple PDSCHs scheduled by DCI of one PDCCH are predefined or configured by the base station when configuring multiple PDSCH scheduling.

Optionally, the base station indicates one DMRS pattern in the DMRS pattern set through the DCI.

Optionally, the base station indicates Quasi-positioning information QCL (Quasi-located information) of the DMRS and the PDSCH, or precoding information. For example, if the base station indicates that the DMRS pattern is periodic, the base station may indicate that a DMRS that is separated from the PDSCH by N slots employs the same precoding matrix as the PDSCH.

Fig. 7 shows a simplified block diagram of an entity 700 suitable for practicing the exemplary embodiments of the present application. The entity 700 may be configured as a network side device, such as a base station, and the entity 700 may also be configured as a user side device, such as a user terminal.

As shown in fig. 7, the entity 700 comprises a processor 701, a memory 702 coupled to the processor 701, and a suitable Radio Frequency (RF) transmitter and receiver 704 coupled to the processor 701. The memory 702 stores a program 703. The transmitter/receiver 704 is adapted for two-way wireless communication. Note that the transmitter/receiver 704 has at least one antenna to facilitate communication, and in practice a base station or UE may have multiple antennas. The entity 700 may be coupled via a data path to one or more external networks or systems, such as the internet.

The program 703 may include program instructions that, when executed by the associated processor 701, cause the entity 700 to operate in accordance with the exemplary embodiments of this application.

Embodiments of the present application may be implemented by computer software executable by the processor 701 of the entity 700, or by hardware, or by a combination of software and hardware.

The memory 702 may be any suitable type of memory suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices and systems, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory, as non-limiting examples only. Although only one memory is shown in entity 700, there may be multiple physically distinct memory units in entity 700. The processor 701 may be any suitable type of processor suitable to the local technical environment, and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, Digital Signal Processors (DSPs) and processors based on a multi-core processor architecture, as non-limiting examples only.

When entity 700 is configured as a user equipment, i.e. entity 700 is a user equipment, in some embodiments a receiver in transmitter/receiver 704 is configured to receive a PDCCH comprising DCI from a base station under the control of processor 701.

The receiver in the transmitter/receiver 704 is further configured to receive, from the base station, a PDSCH scheduled by the PDCCH according to the received DCI in the PDCCH under the control of the processor 701.

A transmitter in the transmitter/receiver 704 is configured to transmit a HARQ-ACK/NACK codebook for a PDSCH to a base station under the control of the processor 701.

When the entity 700 is configured as a network side device, i.e. the entity 700 is a base station, in some embodiments, a transmitter in the transmitter/receiver 704 is configured to transmit a PDCCH including DCI to a terminal under the control of the processor 701.

The transmitter in the transmitter/receiver 704 is also configured to transmit the PDSCH scheduled by the PDCCH to the terminal.

A receiver in the transmitter/receiver 704 is configured to receive a HARQ-ACK/NACK codebook for a PDSCH from a terminal under the control of the processor 701.

It should be understood that the units included in the entity 700 are configured for practicing the exemplary embodiments disclosed herein. Thus, the operations and features described above in connection with fig. 1-6 also apply to the entity 700 and the elements therein, and a detailed description thereof is omitted herein.

As another aspect, the present application also provides a computer-readable storage medium, which may be the computer-readable storage medium included in the base station or the communication device in the above embodiments; or it may be a separate computer readable storage medium not incorporated into the device. The computer readable storage medium stores one or more programs for use by one or more processors in performing the communication methods described herein.

The above description is only a preferred embodiment of the application and is illustrative of the principles of the technology employed. It will be appreciated by a person skilled in the art that the scope of the invention as referred to in the present application is not limited to the embodiments with a specific combination of the above-mentioned features, but also covers other embodiments with any combination of the above-mentioned features or their equivalents without departing from the inventive concept. For example, the above features may be replaced with (but not limited to) features having similar functions disclosed in the present application.

Claims

1. A method performed by a terminal in a wireless communication network, comprising:

receiving a Physical Downlink Control Channel (PDCCH), wherein the PDCCH comprises Downlink Control Information (DCI) used for scheduling one or more Physical Downlink Shared Channels (PDSCHs);

receiving the PDSCH according to the DCI; and

and transmitting a hybrid automatic repeat request acknowledgement (HARQ-ACK/NACK) codebook for the PDSCH.

2. The method of claim 1, wherein the DCI includes a Downlink Allocation Index (DAI), and in the case where one DCI schedules a plurality of PDSCHs, the DAI indicates information of a first PDSCH of the plurality of PDSCHs or information of a last PDSCH of the plurality of PDSCHs.

3. The method of claim 1, wherein the DCI includes a Downlink Allocation Index (DAI), and wherein the DAI includes one or more DAI bit fields each corresponding to DAI information of one PDSCH group, in case that a plurality of PDSCHs scheduled by one PDCCH belong to one or more PDSCH groups.

4. The method of claim 1, wherein prior to transmitting the HARQ-ACK/NACK codebook, the method further comprises:

grouping a plurality of PDSCHs which are fed back in one HARQ-ACK/NACK codebook according to a DCI format for scheduling each PDSCH in the plurality of PDSCHs, wherein the PDSCHs scheduled by the same DCI format belong to the same PDSCH group; and

a codebook for each PDSCH group is determined.

5. The method of claim 1, wherein prior to transmitting the HARQ-ACK/NACK codebook, the method further comprises:

grouping a plurality of PDSCHs fed back in one HARQ-ACK/NACK codebook according to the number of the PDSCHs scheduled by each DCI scheduling the plurality of PDSCHs, wherein the PDSCHs scheduled by the DCI of which the number of the scheduled PDSCHs is larger than a threshold value and the PDSCHs scheduled by the DCI of which the number of the scheduled PDSCHs is equal to or smaller than the threshold value belong to different PDSCH groups; and

a codebook for each PDSCH group is determined.

6. The method of claim 1, wherein prior to transmitting the HARQ-ACK/NACK codebook, the method further comprises:

grouping a plurality of PDSCHs fed back in one HARQ-ACK/NACK codebook according to transmission granularity, wherein the PDSCHs with the same transmission granularity belong to the same PDSCH group, the PDSCHs with different transmission granularity belong to different PDSCH groups, or the PDSCHs with different granularity belong to the same PDSCH group determined according to the transmission granularity of a reference PDSCH; and

a codebook for each PDSCH group is determined.

7. The method of any of claims 4 to 6, wherein determining a codebook for each PDSCH group comprises:

and determining the HARQ-ACK/NACK codebook of each PDSCH group according to the DAI of the PDSCH in each PDSCH group and the HARQ-ACK/NACK bit number corresponding to each PDSCH in each PDSCH group.

8. The method of claim 1, wherein the DCI includes a downlink assignment index DAI for PDCCH count when the number of HARQ-ACK/NACK bits per PDSCH is N_{max_p}The maximum number of PDSCHs belonging to the same PDSCH group scheduled by one PDCCH is N_{max_pdsch}And when the DAI value in the PDSCH group is M, the number of HARQ-ACK/NACK bits N corresponding to the PDCCH_t＝N_{max_p}×N_{max_pdsch}The total number of bits of the transmitted HARQ-ACK/NACK codebook is MxN_t＝M×N_{max_p}×N_{max_pdsch}。

9. The method of claim 1, wherein the DCI includes a downlink allocation index DAI for counting PDSCHs, the DAI indicating information of a last PDSCH of the plurality of PDSCHs scheduled by the DCI, and the number of bits is N when the HARQ-ACK/NACK bit of each PDSCH is N_{max_p}And when the DAI value in one PDSCH group is M, the total number of bits of the HARQ-ACK/NACK codebook to be transmitted is M × N_{max_p}。

10. The method of claim 1, wherein the DCI includes a downlink assignment index DAI for PDCCH counting when a HARQ-ACK/NACK bit number N corresponding to one PDCCH is greater than a predetermined value_tThe total number of bits of the HARQ-ACK/NACK codebook transmitted is M × N, and the DAI value in one PDSCH group is M_tIn which N is_tIs pre-defined or semi-statically configured, and N_tNot less than the sum of HARQ-ACK/NACK bit numbers of each PDSCH scheduled by the PDCCH

11. The method of any one of claims 8 to 10,

the number of HARQ-ACK/NACK bits per PDSCH is N_{max_p}The number of effective HARQ-ACK/NACK bits per PDSCH is N_{r_p}Determining the value of effective HARQ-ACK/NACK according to the decoding result of PDSCH, wherein the value is N_{r_p}Less than N_{max_p}In case of (2), remaining (N) of HARQ-ACK/NACK_{max_p}-N_{r_p}) The value of the bit is determined according to a predefined value; and/or the presence of a gas in the gas,

the number of HARQ-ACK/NACK bits corresponding to each PDCCH is N_t＝N_{max_p}×N_{max_pdsch}The number of PDSCH scheduled by each PDCCH is N_pdschAccording to N_pdschDetermining N from the decoding result of PDSCH_{max_p}×N_pdschTaking the value of HARQ-ACK/NACK of a bit at N_{max_p}×N_pdschLess than N_tIn case of HARQ-ACK/NACK, the remaining N of the HARQ-ACK/NACK_{max_p}×(N_{max_pdsch}-N_pdsch) The value of the bit is determined according to a predefined value.

12. The method of claim 1, in which the DCI includes zero-power channel reference information pilot (ZP) CSI-RS information,

and under the condition that one DCI schedules a plurality of PDSCHs, performing rate matching on the PDSCHs according to ZP CSI-RS information.

13. The method of claim 12, wherein rate matching the plurality of PDSCHs according to ZP CSI-RS information comprises at least one of:

performing rate matching on each PDSCH in the plurality of PDSCHs according to the ZP CSI-RS information, performing rate matching on the PDSCH of each downlink time unit according to the ZP CSI-RS information, performing rate matching on only the first PDSCH according to the ZP CSI-RS information, performing rate matching on the PDSCH in the scheduled first time unit according to the ZP CSI-RS information, and performing rate matching on the PDSCH overlapped with the ZP CSI-RS information according to the ZP CSI-RS information.

14. The method of claim 1, wherein the DCI includes control channel resource set (CORESET) information,

wherein, for the DCI capable of scheduling multiple PDSCHs, the CORESET information includes multiple CORESETs.

15. The method of claim 1, wherein receiving the PDSCH according to the DCI further comprises: receiving a demodulation reference signal (DMRS) of the PDSCH according to the DCI, receiving the PDSCH according to the DMRS,

wherein the DCI indicates a pattern of the DMRS including one or more of periodicity information, time offset information, time length, and symbol position index; and/or

Wherein the DCI indicates location information of the DMRS determined by time domain information of each PDSCH; alternatively, the time domain information of all PDSCHs scheduled by the DCI of one PDCCH is determined in common.

16. A method performed by a base station in a wireless communication network, comprising:

transmitting a Physical Downlink Control Channel (PDCCH), wherein the PDCCH comprises Downlink Control Information (DCI) used for scheduling one or more Physical Downlink Shared Channels (PDSCHs);

transmitting the PDSCH according to the DCI; and

receiving a hybrid automatic repeat request acknowledgement (HARQ-ACK/NACK) codebook for the PDSCH.

17. The method of claim 16, wherein the DCI includes a Downlink Allocation Index (DAI), and in the case where one DCI schedules a plurality of PDSCHs, the DAI indicates information of a first PDSCH of the plurality of PDSCHs or information of a last PDSCH of the plurality of PDSCHs.

18. A terminal in a wireless communication network, comprising:

a transceiver; and

a processor coupled with the transceiver and configured to control the transceiver to perform the method of any of claims 1-15.

19. A base station in a wireless communication network, comprising:

a transceiver; and

a processor coupled with the transceiver and configured to control the transceiver to perform the method of any of claims 16 to 17.

20. A computer-readable storage medium storing computer instructions which, when executed by a processor, are capable of causing the processor to perform the method of any one of claims 1 to 17.