WO2023011090A1 - Method and apparatus for retransmitting feedback information - Google Patents

Abstract

A method and apparatus for retransmitting feedback information. The method comprises: a terminal receives a group of DCI from a base station, first DCI in the group of DCI being used for instructing the terminal to retransmit first HARQ information; and the terminal sends the first HARQ information to the base station. The use of the method can achieve retransmission of cancelled HARQ information.

Description

Method and device for retransmitting feedback information

Cross References to Related Applications

This application is required to be submitted to the Intellectual Property Office of the People's Republic of China on August 6, 2021, the application number is 202110904374.6, and the title of the invention is "A Method and Device for Retransmitting Feedback Information" and submitted to the People's Republic of China on November 5, 2021 Intellectual Property Office, the priority of the Chinese patent application with the application number 202111306570.X and the title of the invention "A method and device for retransmitting feedback information", the entire content of which is incorporated in this application by reference.

technical field

The embodiments of the present application relate to the field of communication technologies, and in particular to a method and device for retransmitting feedback information.

Background technique

Compared with previous generations of mobile communication systems, the fifth generation ( ^5th generation, 5G) communication system has higher requirements in terms of transmission rate, delay and power consumption. The International Telecommunication Union (ITU) will enhance mobile broadband (enhanced Mobile Broadband, eMBB), massive machine type communication (massive machine type communication, mMTC) and ultra-reliable and low-latency communication (ultra-reliable and low-latency communication) , URLLC) are defined as the three typical services of 5G. Among them, the URLLC service is one of the three typical services of 5G. Its main application scenarios include: driverless driving, telemedicine, etc. These application scenarios put forward stricter requirements in terms of reliability and delay. The specific requirements of the URLLC service include: data transmission reliability of 99.999%, transmission delay of less than 1ms, and reducing instruction overhead as much as possible while meeting the requirements of high reliability and low delay. A hybrid automatic repeat request (HARQ) mechanism is adopted to help ensure the reliability and delay of the URLLC service. How the UE retransmits the HARQ information is a technical problem to be solved in the embodiment of the present application.

Contents of the invention

Embodiments of the present application provide a method and device for retransmitting feedback information, so as to implement retransmission of HARQ information to a base station and improve reliability of feedback information transmission.

In a first aspect, a method for retransmitting feedback information is provided, the method comprising: a terminal device receives a set of downlink control information DCI from a network device, and the first DCI in the set of DCI instructs the terminal device to retransmit First hybrid automatic repeat request HARQ information; the terminal device sends the first HARQ information to the network device.

In a possible design, the first DCI includes a first field, the first field is a field of a reused scheduled PDSCH, and the first field is used to indicate configuration information of the first HARQ information. Optionally, the configuration information includes a time domain position of the first HARQ information.

In the above design, the first DCI does not schedule the PDSCH, and the field of scheduling the PDSCH can be reused to indicate the configuration of the first HARQ information, saving DCI overhead.

In a possible design, only the first DCI in the group of DCIs instructs the terminal device to retransmit the first HARQ information. Optionally, the first DCI is the DCI with the last time domain position in a group of DCIs.

In this design, only one DCI in a group of DCI indicates the retransmission of the first HARQ information, which can reduce the signaling overhead of the DCI.

In a possible design, except for the first DCI in the group of DCIs, each DCI in the other DCIs schedules a PDSCH respectively, and the method further includes: the terminal device sends the second HARQ information to the network device , the second HARQ information includes HARQ feedback information of PDSCHs scheduled by other DCIs except the first DCI in the group of DCIs.

In a possible design, the terminal device determines a target PUCCH resource set from a preset physical uplink control channel PUCCH resource set according to the payload size of the first HARQ information and the payload size of the second HARQ information, and the The target PUCCH resource set includes at least one PUCCH resource; and according to the PUCCH resource indication PRI of the DCI with the last time domain position in the set of DCI, determine the first PUCCH resource in the target PUCCH resource set; further, The terminal device sends the first HARQ information and the second HARQ information to the network device by using the first PUCCH resource.

In a possible design, the terminal device determines a target PUCCH resource set from a preset PUCCH resource set according to the load size of the first HARQ information and the load size of the second HARQ information, and the target PUCCH resource include at least one PUCCH resource in the set; and

Only the first DCI in the set of DCI instructs the terminal device to retransmit the first HARQ information, and the first HARQ information indicated by the first DCI is invalid, then according to the set of DCI In addition to the first DCI, the PRI of the last DCI in the time domain,

In the target PUCCH resource set, determine a second PUCCH resource; further, the terminal device sends the first HARQ information and the second HARQ information to the network device through the second PUCCH resource.

In a possible design, the terminal device determines a target PUCCH resource set from a preset PUCCH resource set according to the load size of the first HARQ information and the load size of the second HARQ information, and the target PUCCH resource include at least one PUCCH resource in the set; and

In the set of DCIs, only the first DCI instructs the terminal device to retransmit the first HARQ information, and the first HARQ information indicated by the first DCI is valid, then according to the first DCI PRI, determining a third PUCCH resource in the target PUCCH resource set; further, the terminal device sends the first HARQ information and the second HARQ information to the network device through the third PUCCH resource.

In a possible design, the first DCI also indicates a payload size of the first HARQ information.

In this design, the DCI of scheduling the PDSCH corresponding to the first HARQ information may be missed, so that the payload size of the first HARQ information determined by the terminal device is wrong. In the above design, the network device instructs the terminal device on the load size of the first HARQ information, so as to avoid the inconsistency between the terminal device and the network device on the load size of the first HARQ information, thereby avoiding affecting the network device's understanding of the second HARQ information. reception.

The second aspect provides a method for retransmitting feedback information, which is a method on the network device side corresponding to the first aspect, and its beneficial effect can refer to the beneficial effect of the first aspect. The method includes: the network device sends a group of downlink control information DCI to the terminal device, and the first DCI in the group of DCI instructs the terminal device to retransmit the first hybrid automatic repeat request HARQ information; the network device receives the HARQ information from the The first HARQ information of the terminal device.

In a possible design, the first DCI includes a first field, the first field is a field of a reusable physical downlink shared channel PDSCH, and the first field is used to indicate the first HARQ information configuration information.

In a possible design, only the first DCI in the set of DCIs instructs the terminal device to retransmit the first HARQ information, and the first DCI is a time domain position in the set of DCIs The last DCI.

In a possible design, except for the first DCI in the group of DCIs, each DCI in the other DCIs schedules a PDSCH respectively, and the method further includes: the network device receives the first DCI from the terminal device Two HARQ information, where the second HARQ information includes HARQ feedback information of PDSCHs scheduled by other DCIs in the group of DCIs except the first DCI.

In a possible design, the network device receiving the first HARQ information and the second HARQ information from the terminal device includes: the network device receiving the first HARQ information according to the load size of the first HARQ information and the second HARQ information The load size of the HARQ information determines the target PUCCH resource set from the preset physical uplink control channel PUCCH resource set, and the target PUCCH resource set includes at least one PUCCH resource; the network device according to the time domain position in the set of DCI is the closest The PUCCH resource indication PRI of the subsequent DCI determines the first PUCCH resource in the target PUCCH resource set; the network device receives the first HARQ information and the first PUCCH resource from the terminal device through the first PUCCH resource Two HARQ information.

In a possible design, the network device receiving the first HARQ information and the second HARQ information from the terminal device includes: the network device receiving the first HARQ information according to the load size of the first HARQ information and the second HARQ information The load size of the HARQ information determines the target PUCCH resource set from the preset PUCCH resource set, and the target PUCCH resource set includes at least one PUCCH resource; only the first DCI in the set of DCI indicates the terminal device retransmit the first HARQ information, and the first HARQ information indicated by the first DCI is invalid, then the network device according to the set of DCIs except the first DCI, the time domain position closest to After the PRI of the DCI, the second PUCCH resource is determined in the target PUCCH resource set; the network device receives the first HARQ information and the second HARQ information from the terminal device through the second PUCCH resource .

In a possible design, the network device receiving the first HARQ information and the second HARQ information from the terminal device includes: the network device receiving the first HARQ information according to the load size of the first HARQ information and the second HARQ information The load size of the HARQ information determines the target PUCCH resource set from the preset PUCCH resource set, and the target PUCCH resource set includes at least one PUCCH resource; only the first DCI in the set of DCI indicates the terminal device retransmit the first HARQ information, and the first HARQ information indicated by the first DCI is valid, then the network device determines a third PUCCH resource in the target PUCCH resource set according to the PRI of the first DCI The network device receives the first HARQ information and the second HARQ information from the terminal device through the third PUCCH resource.

In a possible design, the first DCI also indicates a payload size of the first HARQ information.

In the third aspect, a device is provided, and the beneficial effect can be referred to the description in the first aspect. The device may be a terminal device, or a module configured in the terminal device, or other devices having functions of the terminal device. In one design, the device includes a unit for executing the method described in the first aspect, and the unit may be a hardware circuit, or software, or a combination of hardware circuit and software. Exemplarily, the device may include a processing unit and a communication unit, and the processing unit and the communication unit may perform corresponding functions in any design example of the first aspect above, specifically:

A communication unit, configured to receive a set of downlink control information DCI from a network device, each DCI in the set of DCI schedules a physical downlink shared channel PDSCH respectively, and the first DCI in the set of DCI also indicates the The terminal device retransmits the first hybrid automatic repeat request HARQ information;

a processing unit, configured to determine first HARQ information and second HARQ information;

The communication unit is further configured to send the first HARQ information and the second HARQ information to the network device, where the second HARQ information includes HARQ feedback information of the PDSCHs scheduled by the set of DCIs.

For the specific execution process of the communication unit and the processing unit, refer to the first aspect.

In a fourth aspect, a device is provided, and the beneficial effects may refer to the description in the first aspect, and the device includes a processor configured to implement the method described in the first aspect above. The apparatus may also include memory for storing instructions and/or data. The memory is coupled to the processor, and when the processor executes the program instructions stored in the memory, the method described in the first aspect above can be implemented. The device may also include a communication interface for the device to communicate with other devices. Exemplarily, the communication interface may be a transceiver, circuit, bus, pin or other types of communication interface. In one possible design, the device includes:

memory for storing program instructions;

A communication interface, configured to perform the functions of the communication unit in the third aspect above;

A processor, configured to execute the functions of the processing unit in the above third aspect.

In the fifth aspect, there is provided a device. For the beneficial effect, please refer to the description in the second aspect. The device may be a network device, or a module configured in the network device, or other devices having the function of the network device. In one design, the device includes a unit for executing the method described in the second aspect. The unit may be a hardware circuit, or software, or may be implemented by combining hardware circuits with software. Exemplarily, the device may include a processing unit and a communication unit, and the processing unit and the communication unit may perform corresponding functions in any design example of the second aspect above, specifically:

A communication unit, configured to send a set of downlink control information DCI to the terminal device, each DCI in the set of DCI schedules a physical downlink shared channel PDSCH respectively, and the first DCI in the set of DCI also instructs the terminal The device retransmits the first hybrid automatic repeat request HARQ information; and, receives the first HARQ information and the second HARQ information from the terminal device, and the second HARQ information includes the set of DCI scheduled HARQ feedback information of the PDSCH.

A processing unit, configured to process the first HARQ information and the second HARQ information.

For the specific execution process of the communication unit and the processing unit, please refer to the second aspect.

According to the sixth aspect, there is provided a device, and the beneficial effect can be referred to the description of the second aspect, and the device includes a processor, configured to implement the method described in the second aspect above. The apparatus may also include memory for storing instructions and/or data. The memory is coupled to the processor, and when the processor executes the program instructions stored in the memory, the method described in the second aspect above can be implemented. The device may also include a communication interface for the device to communicate with other devices. Exemplarily, the communication interface may be a transceiver, circuit, bus, pin or other types of communication interface. In one possible design, the device includes:

memory for storing program instructions;

A communication interface, configured to perform the functions of the communication unit in the fifth aspect above;

A processor, configured to execute the functions of the processing unit in the fifth aspect above.

In the seventh aspect, the embodiment of the present application further provides a computer-readable storage medium storing instructions, and when the instructions are run on the communication device, the communication device is made to execute the method of the first aspect or the second aspect.

In an eighth aspect, the embodiment of the present application further provides a chip system, where the chip system includes a processor and may further include a memory, for implementing the method of the first aspect or the second aspect. The system-on-a-chip may consist of chips, or may include chips and other discrete devices.

In a ninth aspect, the embodiments of the present application further provide a computer program product, including instructions, which, when run on a communication device, cause the communication device to execute the method of the first aspect or the second aspect.

In a tenth aspect, the embodiment of the present application further provides a system, the system includes the device in the third aspect or the fourth aspect, and the device in the fifth aspect or the sixth aspect.

Description of drawings

FIG. 1 is a schematic structural diagram of a mobile communication system applied in an embodiment of the present application;

FIG. 2 is a schematic diagram of a scene provided by an embodiment of the present application;

FIG. 3a and FIG. 3b are schematic diagrams of HARQ feedback provided by the embodiment of the present application;

FIG. 4 is a schematic diagram of DCI missed detection provided by the embodiment of the present application;

FIG. 5 is a flowchart of a communication method provided by an embodiment of the present application;

FIG. 6 is a schematic diagram of PUCCH resource mapping provided by an embodiment of the present application;

7 to 9 are schematic diagrams of DCI indicating retransmission of the first HARQ information provided by the embodiments of the present application;

FIG. 10 and FIG. 11 are schematic diagrams of the device provided by the embodiment of the present application.

Detailed ways

FIG. 1 is a schematic structural diagram of a communication system 1000 applied in an embodiment of the present application. As shown in FIG. 1 , the communication system includes a radio access network 100 and a core network 200 , and optionally, the communication system 1000 may also include the Internet 300 . Wherein, the radio access network 100 may include at least one radio access network device (such as 110a and 110b in FIG. 1 ), and may also include at least one terminal (such as 120a-120j in FIG. 1 ). The terminal is connected to the wireless access network device in a wireless manner, and the wireless access network device is connected to the core network in a wireless or wired manner. The core network equipment and the wireless access network equipment can be independent and different physical equipment, or the functions of the core network equipment and the logical functions of the wireless access network equipment can be integrated on the same physical equipment, or it can be a physical equipment It integrates some functions of core network equipment and some functions of wireless access network equipment. Terminals and wireless access network devices may be connected to each other in a wired or wireless manner. FIG. 1 is only a schematic diagram. The communication system may also include other network devices, such as wireless relay devices and wireless backhaul devices, which are not shown in FIG. 1 .

The radio access network equipment can be a base station (base station), an evolved base station (evolved NodeB, eNodeB), a transmission reception point (transmission reception point, TRP), and the next generation in the fifth generation (5th generation, 5G) mobile communication system Base station (next generation NodeB, gNB), the next generation base station in the sixth generation (6th generation, 6G) mobile communication system, the base station in the future mobile communication system or the access node in the wireless fidelity (wireless fidelity, WiFi) system etc.; it can also be a module or unit that completes some functions of the base station, for example, it can be a centralized unit (central unit, CU) or a distributed unit (distributed unit, DU). The CU here completes the functions of the base station's radio resource control (radio resource control, RRC) protocol and packet data convergence protocol (PDCP), and can also complete the service data adaptation protocol (service data adaptation protocol, SDAP) The function; the DU completes the functions of the radio link control (radio link control, RLC) layer and medium access control (medium access control, MAC) layer of the base station, and can also complete part of the physical (PHY) layer or all physical layers. For the specific description of each protocol layer above, you can refer to the relevant technical specification (TS) of the third generation partnership project (3rd generation partnership project, 3GPP). The radio access network device may be a macro base station (such as 110a in Figure 1), a micro base station or an indoor station (such as 110b in Figure 1), or a relay node or a donor node. The embodiment of the present application does not limit the specific technology and specific equipment form adopted by the radio access network equipment. For ease of description, the wireless access network device may be referred to as network device for short, and the following description uses a base station as an example of the network device.

A terminal may also be called terminal equipment, user equipment (user equipment, UE), mobile station, mobile terminal, and so on. Terminals can be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things ( internet of things, IOT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grid, smart furniture, smart office, smart wearables, smart transportation, smart city, etc. Terminals can be mobile phones, tablet computers, computers with wireless transceiver functions, wearable devices, vehicles, drones, helicopters, airplanes, ships, robots, robotic arms, smart home devices, etc. The embodiment of the present application does not limit the specific technology and specific device form adopted by the terminal. For ease of description, UE is used as an example of a terminal for description below.

Base stations and terminals can be fixed or mobile. Base stations and terminals can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; they can also be deployed on aircraft, balloons and artificial satellites in the air. The embodiments of the present application do not limit the application scenarios of the base station and the terminal.

The roles of the base station and the terminal can be relative. For example, the helicopter or UAV 120i in FIG. base station; however, for base station 110a, 120i is a terminal, that is, communication between 110a and 120i is performed through a wireless air interface protocol. Of course, communication between 110a and 120i may also be performed through an interface protocol between base stations. In this case, compared to 110a, 120i is also a base station. Therefore, both the base station and the terminal can be collectively referred to as a communication device, 110a and 110b in FIG. 1 can be referred to as a communication device with a base station function, and 120a-120j in FIG. 1 can be referred to as a communication device with a terminal function.

The communication between the base station and the terminal, between the base station and the base station, and between the terminal and the terminal can be carried out through the licensed spectrum, the communication can also be carried out through the unlicensed spectrum, and the communication can also be carried out through the licensed spectrum and the unlicensed spectrum at the same time; Communications may be performed on frequency spectrums below megahertz (gigahertz, GHz), or communications may be performed on frequency spectrums above 6 GHz, or communications may be performed using both frequency spectrums below 6 GHz and frequency spectrums above 6 GHz. The embodiments of the present application do not limit the frequency spectrum resources used for wireless communication.

In the embodiments of the present application, the functions of the base station may also be performed by modules (such as chips) in the base station, or may be performed by a control subsystem including the functions of the base station. The control subsystem including base station functions here may be the control center in the above application scenarios such as smart grid, industrial control, intelligent transportation, and smart city. The functions of the terminal may also be performed by a module (such as a chip or a modem) in the terminal, or may be performed by a device including the terminal function.

In this application, the base station sends a downlink signal or downlink information to the terminal, and the downlink information is carried on the downlink channel; the terminal sends an uplink signal or uplink information to the base station, and the uplink information is carried on the uplink channel. In order to communicate with the base station, the terminal needs to establish a wireless connection with the cell controlled by the base station. A cell with which a terminal has established a wireless connection is called a serving cell of the terminal. When the terminal communicates with the serving cell, it will also be interfered by signals from neighboring cells.

It can be understood that, in the embodiments of the present application, a physical downlink shared channel (physical downlink shared channel, PDSCH), a physical downlink control channel (physical downlink control channel, PDCCH), a physical uplink shared channel (physical uplink shared channel, PUSCH) And physical uplink control channel (PUCCH) is just an example of downlink data channel, downlink control channel, uplink data channel and uplink control channel. In different systems and different scenarios, data channel and control channel There may be different names, which are not limited in the embodiments of the present application.

The HARQ technology is an efficient retransmission mechanism. The basic principle is that the UE receives downlink data from the base station, and the downlink data can be carried on the PDSCH. If the UE correctly receives the downlink data, it will feed back a positive acknowledgment (acknowledgment, ACK) to the base station; if the UE does not correctly receive the downlink data, then the UE will feed back a negative acknowledgment (negative acknowledgment, NACK) to the base station. When receiving the NACK fed back by the UE, the base station may retransmit the above-mentioned downlink data. Using HARQ technology, on the one hand, the transmission reliability of downlink data can be improved through retransmission; on the other hand, only when the UE feedbacks NACK, the base station needs to retransmit, which reduces the overall resource consumption of data transmission. The ACK and NACK here may be referred to as HARQ feedback information, or may be simply referred to as HARQ information or feedback information.

In an example, the HARQ feedback process is as follows: the base station sends downlink control information (DCI) to the UE, the DCI instructs the UE to receive downlink data carried on the PDSCH, and sends a HARQ message for the downlink data. The HARQ message of the downlink data may be carried on the PUCCH. As shown in Figure 2, the base station indicates the transmission parameters of two downlink data through DCI 0 and DCI 1, and also indicates the PUCCH resources for feeding back the HARQ information of the two downlink data, namely: PUCCH 0 and PUCCH 1. When PUCCH 0 conflicts with PUCCH 1, and the priority of the HARQ information carried on PUCCH 0 is lower than that of the HARQ information carried on PUCCH 1, the UE may cancel the transmission of the HARQ information carried on PUCCH 0. When the HARQ information carried on PUCCH 0 is canceled, the UE may not discard the canceled HARQ information, but retransmit the canceled HARQ information to the base station. How the UE retransmits the above-mentioned canceled HARQ information to the base station is a technical problem to be solved in the embodiments of the present application.

Based on the above, the embodiment of the present application provides the following solution: the base station sends a set of DCI to the UE, and the first DCI in the set of DCI instructs the terminal device to retransmit the first HARQ information; The base station sends first HARQ information.

For ease of understanding, firstly, the communication terms or nouns involved in the embodiments of the present application are explained.

1. HARQ feedback

The UE feeds back HARQ information on an uplink slot (slot). In one design, the mechanism of feeding back multiple HARQ information together on the same uplink time slot is adopted. In this uplink time slot, the UE can simultaneously feed back whether the multiple downlink data scheduled by the base station through multiple DCIs are received correctly. The HARQ information corresponding to the downlink data can be concatenated together to form a HARQ codebook. As shown in Figure 3a, the base station sends 6 DCIs to the UE, and schedules PDSCH 1 to PDSCH 6 respectively. The HARQ information corresponding to PDSCH 1 to PDSCH 3 is concatenated together to form the first HARQ codebook, and the first HARQ codebook is sent on PUCCH 1, which occupies the first sub-slot in slot n+3; PDSCH The HARQ information corresponding to 4 to PDSCH6 is concatenated together to form a second HARQ codebook, and the second HARQ codebook is sent on PUCCH 2, and the PUCCH 2 occupies the second sub-slot in time slot n+3. Each slot may include 2 sub-slots.

2. Downlink assignment index (DAI)

For type 2 HARQ-ACK codebook (type 2HARQ-ACK codebook) feedback: In actual data transmission, the UE may miss the DCI sent by the base station through the PDCCH. For example, the base station sends a certain DCI to the UE, but the UE does not receive the DCI, or does not correctly decode the DCI, which may result in one bit missing in the HARQ information fed back by the UE to the base station. For example, the base station sends 3 DCIs to the UE, and the HARQ information corresponding to the 3 DCIs is 3 bits. However, due to some reasons, the UE missed a DCI, and the HARQ information fed back may be only 2 bits. However, the base station does not know that the UE has not received the above-mentioned DCI, which may lead to inconsistencies between the UE and the base station in understanding the load size of the HARQ information. The base station still divides and decodes the received data according to the load size of the expected HARQ information. This leads to decoding errors of subsequent HARQ information bits and even other types of subsequent uplink control information (UCI).

In order to assist the UE to find the missing DCI, if the feedback of multiple DCI-scheduled PDSCHs points to the same HARQ codebook, the base station will introduce DAI into these DCIs to indicate the number of the current DCI, which is called counting DAI ( counter DAI, C-DAI).

Table 1: Example frame structure

1	2	3	4	5	6	7	8	9	10
D.	D.	D.	D.	D.	D.	D.	S	u	u

For example, as shown in Table 1, take the frame structure ratio of 10 time slots as 8:2, that is, DDDDDDDSUU as an example. The indices of the 10 time slots are time slot 1 to time slot 10 in sequence. Among them, on time slot 3 to time slot 6, the UE is scheduled to send 4 PDSCHs by DCI 0, DCI 1, DCI 2 and DCI 3 respectively, and these four DCIs point to the uplink time slot of time slot 10 to send HARQ information. If the four DCIs are all in the DCI format 1-0 or 1-1, then the values of the C-DAI fields in the four DCIs can be 1, 2, 3, and 4 in sequence. If the UE misses DCI 3, after receiving DCI 0, DCI1, and DCI 4, the UE will recognize that the values of C-DAI are 1, 2, and 4, and thus know that DCI 3 is missed. When feeding back the HARQ information, the UE will fill in the missing DCI 3 bit position with NACK, and then feed it back to the base station to ensure that the load size and sequence of the HARQ information are correct. However, if DCI4 is missed by the UE, the DCI 0, DCI 1, and DCI 2 received by the UE correspond to C-DAI values of 1, 2, and 3, respectively. At this time, since the C-DAI values received by the UE are continuous, the UE cannot identify DCI 4 missed detection. It should be noted that in the frame structure example in Table 1 above, D represents downlink, U represents uplink, and S represents a special time slot, including uplink and downlink switching points.

In the case of DCI missed detection, in the case of multiple carriers, the concept of total DAI (total DAI, T-DAI) is also introduced, and the T-DAI is used to indicate the amount of DCI on all carriers as of the current moment.

As shown in FIG. 4 , the base station uses two carriers, namely carrier 1 and carrier 2, to send DCI to the UE. Wherein, in time slot 1, the base station uses carrier 1 to send the first DCI to the UE, and the values of C-DAI and T-DAI of the first DCI are (1, 1) respectively. In time slot 2, the base station uses carrier 1 and carrier 2 to send the second DCI and the third DCI to the UE, the values of C-DAI and T-DAI of the second DCI are (2, 3) respectively, and the values of the third DCI The values of C-DAI and T-DAI are (3, 3) respectively. In time slot 4, the base station uses carrier 1 and carrier 2 to send the fourth DCI and the fifth DCI to the UE respectively, the values of C-DAI and T-DAI of the fourth DCI are (4, 5) respectively, and the fifth DCI The values of C-DAI and T-DAI are (5, 5) respectively. If the UE misses detecting the third DCI, the UE may know that the UE missed detecting the third DCI according to the values of the C-DAI of the received DCI being 1, 2, 4, and 5 respectively. Alternatively, the UE may know that there should be a DCI indicating (3, 3) at this moment according to the T-DAI of the time slot 2. The T-DAI of each time slot refers to the total number of DCIs sent before the end of each time slot. The value of T-DAI of the second DCI received by the UE in time slot 2 is 3. But at the end of the second time slot, the UE only receives 2 DCIs, namely the first DCI and the second DCI. Therefore, the UE can determine that a DCI should be missed in the time slot 2, and the DAIs of the DCIs can be (3, 3) respectively. When the UE feeds back the HARQ codebook to the base station, it can complete the HARQ information corresponding to this position. For example, when the UE misses detecting the third DCI, the HARQ codebook fed back by the UE to the base station may specifically be (AN, AN, N, AN, AN), where AN represents ACK or NACK. The N indicates NACK.

Optionally, in the embodiment of the present application, C-DAI and T-DAI can each occupy 2 bits in the DCI, because 2 bits can only represent 4 values, so modulo 4 processing is adopted. 00, 01, 10 and 11 cycle counts can be used for C-DAI and T-DAI. For a more detailed description of DAI, please refer to the descriptions in relevant chapters in 3GPP TS 38.212 and TS 38.213.

For the type 1 HARQ-ACK codebook (type 1HARQ-ACK codebook), the Type1 HARQ-ACK codebook is fed back: that is, the semi-static codebook. In the uplink time slot, the HARQ of the PDSCH in the corresponding downlink time slot will be fed back according to the indication of the K1 set. Among them, it includes not only the HARQ corresponding to the PDSCH that has been sent, but its real ACK or NACK is fed back, but also the HARQ that has the PDSCH transmission opportunity but no actual PDSCH data transmission, and the NACK is fed back. Then these HARQs are sorted according to the rule of time sorting in the carrier first, and then according to the carrier sorting rule to form a HARQ codebook. As shown in Figure 3b, there are a total of 4 time slots and two carriers. The position of the slash has PDSCH transmission, the position of white has no PDSCH transmission, and the position of black indicates that the HARQ codebook feedback is on the uplink time slot of carrier 1. . Taking the K1 set as {1, 2, 3, 4} as an example, according to the rules of the type1 codebook, the feedback HARQ codebook totals 8 bits, and the sequence is (N, AN, N, AN). Wherein, N represents the transmission of NACK, and AN represents the transmission of the actual ACK or NACK corresponding to the PDSCH. Or, if the K1 set is {1,2}, then only the HARQ feedback corresponding to the PDSCH of the downlink time slot with the uplink time slot interval of 1 and 2 is fed back, and the order of the feedback HARQ is {N, AN, N, AN} .

It should be noted that, in this application, the aforementioned K1 set is preconfigured or predefined. The UE needs to feedback the HARQ information according to the K1 set. For example, the above K1 set is {1, 2}, and the terminal sends HARQ information in time slot 5 of carrier 1, which means that the terminal needs to feed back the HARQ feedback of the position 1 time slot and 2 time slots away from the above time slot 5 . Referring to FIG. 3 b , it can be seen that the time slots one and two times away from the above-mentioned time slot 5 are respectively time slot 3 and time slot 4 . Then the UE can feed back the HARQ feedback corresponding to the time slot 3 and the time slot 4. According to the time ordering in the carrier first, and then according to the carrier ordering regulations, the finally fed back HARQ information is (N, AN, N, AN).

For the type 1 HARQ-ACK codebook fed back on the PUCCH, there may be two codebook composition methods. If the UE detects only 1 HARQ bit, that is, only one DCI schedules a PDSCH, then the UE will not form a complete codebook, but only feeds back 1-bit HARQ-ACK. If multiple DCIs schedule PDSCH, that is, the UE If the number of detected HARQ bits is more than 1 bit, the UE feeds back a complete type1 HARQ-ACK codebook.

Optionally, if the first HARQ information is concatenated after the second HARQ information, due to the loss of DCI, the UE may only feed back 1 bit HARQ information, but the base station considers it to be a complete type 1 code This is decoded, resulting in an error.

3. Time unit

A unit of a time unit may be a radio frame, a subframe, a time slot, a sub-slot, or a symbol. One radio frame may include one or more subframes, and one subframe may include one or more time slots. There may be different slot lengths for different subcarrier spacings. For example, when the subcarrier interval is 15kHz, one time slot can be 1 millisecond. When the subcarrier interval is 30 kHz, one time slot can be 0.5 milliseconds or the like. A slot may consist of one or more symbols. For example, a time slot under a normal cyclic prefix (CP) may include 14 time domain symbols, and a time slot under an extended CP may include 12 time domain symbols. A time-domain symbol may be simply called a symbol. The time-domain symbol can be an orthogonal frequency division multiplexing (OFDM) symbol, or an orthogonal frequency division multiplexing (discrete fourier transform spread orthogonal frequency division multiplexing, DFT-s-s- OFDM) symbols. A sub-slot is also called a mini-slot or a mini-slot, which may be a unit smaller than a time slot, and a sub-slot may include one or more symbols. For example, a sub-slot may include 2 symbols, 4 symbols or 7 symbols and so on. A slot may include one or more sub-slots.

As shown in Figure 5, the embodiment of the present application provides a method for retransmitting feedback information, at least including the following steps:

Step 500: the base station sends a set of DCI to the UE, and correspondingly, the UE receives a set of DCI from the base station.

The above group of DCIs may be composed of DCIs satisfying certain rules. For example, the set of DCI includes a first DCI, and the first DCI is used to instruct the UE to retransmit the first HARQ information.

In one design, only the first DCI in the set of DCI instructs the UE to retransmit the first HARQ information. Optionally, the first DCI may be the last DCI in the time domain. Except for the first DCI in a group of DCIs, each DCI in the other DCIs schedules a PDSCH respectively. Except for the first DCI, the HARQ feedback information of the PDSCHs scheduled in the group of DCIs is fed back on the same time unit or on the same PUCCH resource. In this group of DCIs, except for the first DCI, HARQ feedback information of PDSCHs scheduled by other DCIs form a HARQ codebook, which is called second HARQ information. Or described as, the HARQ feedback information indicated by each DCI in this group of DCIs is fed back on the same time unit or on the same PUCCH resource, but the first DCI in this group of DCIs does not schedule the PDSCH, but only indicates the The retransmission of the first HARQ information is also fed back on the same time unit or the same PUCCH resource as the PDSCH scheduled by other DCIs.

In the present application, the above-mentioned first DCI may include a first field, the first field is a field of the reused scheduling PDSCH, and the first field may be used to indicate configuration information of the first HARQ information. Optionally, the configuration information includes a time domain position for retransmitting the first HARQ information. Since the first DCI does not schedule PDSCH, the field originally used to indicate the scheduling of PDSCH in the first DCI can be used to carry the configuration information of the first HARQ information, that is, reuse the field of scheduling PDSCH, and the first field is used for Indicates configuration information of the first HARQ information. For example, when scheduling PDSCH, DCI includes modulation and coding scheme (modulation and coding scheme, MCS) field 5bits, new data indicator (new data indicator, NDI) field 1bit, redundancy version (redundancy version, RV) field 2bit , HARQ process number (HARQ process number, HPN) field 4bit, etc. When the first DCI does not schedule the PDSCH and indicates retransmission of the first HARQ information, the above one or more fields may be used to indicate configuration information for retransmission of the first HARQ information. For example, the MCS field may be used to indicate the time domain position for retransmitting the first HARQ information, and the like.

For example, the base station sends 6 DCIs to the UE, the first 5 DCIs schedule PDSCH1 to PDSCH5, and the last DCI (ie DCI6) does not schedule PDSCH, but indicates retransmission of the first HARQ information. PDSCH 4, PDSCH 5 and the retransmitted first HARQ information are concatenated together to form the second HARQ codebook, and the second HARQ codebook is sent on PUCCH 2, which occupies the second sub-time in slot n+3 Gap. The DCI 4 to DCI 6 may be called a set of DCI, and the HARQ information corresponding to the PDSCH 4 to PDSCH 5 scheduled by the DCI 4 to DCI 5 may be called the second HARQ information.

In another design, each DCI in the group of DCIs schedules a PDSCH respectively, and the HARQ feedback information of the PDSCHs scheduled by the group of DCIs is fed back in the same time unit or the same PUCCH resource. The HARQ feedback information of the PDSCH scheduled by this group of DCI forms a HARQ codebook, which may be called the second HARQ information. The first DCI in the foregoing group of DCIs may also instruct the UE to retransmit the first HARQ information. The first HARQ information may be HARQ information previously canceled by the UE for transmission. For example, because the PUCCH resource of the first HARQ information conflicts with the PUCCH resources of other HARQ information, and the priority of the first HARQ information is low, the transmission of the first HARQ information is canceled.

For example, as shown in Figure 3a, the base station sends 6 DCIs to the UE, and schedules PDSCH 1 to PDSCH 6 respectively. The HARQ information corresponding to PDSCH 1 to PDSCH 3 is concatenated together to form the first HARQ codebook, and the first HARQ codebook is sent on PUCCH 1, which occupies the first sub-slot in slot n+3; PDSCH The HARQ information corresponding to PDSCH 4 to PDSCH 6 is concatenated together to form a second HARQ codebook, and the second HARQ codebook is sent on PUCCH 2, and the PUCCH 2 occupies the second sub-slot in time slot n+3. Each slot may include 2 sub-slots. DCI 1 to DCI 3 may be called a set of DCIs, or DCI 4 to DCI 6 may also be called a set of DCIs. Taking DCI 1 to DCI 3 as a group of DCI as an example, the HARQ information corresponding to PDSCH 1 to PDSHC 3 scheduled by DCI 1 to DCI 3 may be called the second HARQ information. At least one DCI among DCI 1 to DCI 3 may also indicate retransmission of the first HARQ information and the like.

Step 501: The UE sends the first HARQ information and the second HARQ information to the base station, and the second HARQ information includes the HARQ feedback information of the PDSCH scheduled by the above-mentioned group of DCIs.

In one design, the UE may determine a target PUCCH resource set from a preset PUCCH resource set according to the payload size (payload size) of the first HARQ information and the payload size of the second HARQ information, and the target PUCCH resource set includes At least one PUCCH resource; according to the PUCCH resource indicator (PUCCH resource indicator, PRI) of the DCI with the last time domain position in the group of DCIs, in the target PUCCH resource set, determine the first PUCCH resource; UE through the first PUCCH resource , sending the first HARQ information and the second HARQ information to the base station.

For example, taking a group of DCIs including DCI 1, DCI 2, and DCI 3 as an example, the DCI 3 is the DCI with the last time domain position in the group of DCIs. The last DCI in the time domain position in a group of DCIs may refer to the last DCI of the start symbol of the PDCCH carrying the DCI, or the last DCI of the end symbol of the PDCCH carrying the DCI in a group of DCIs sent by the base station . The UE may determine the first PUCCH resource in the target PUCCH resource set according to the PRI in DCI 3.

Exemplarily, each PUCCH resource set in the aforementioned preset PUCCH resource set may be configured by the base station to the UE through high-level signaling, such as RRC signaling, or may also be specified by a protocol. There is a mapping relationship between the PUCCH resource set and the payload size. The UE may calculate the sum of the payload size of the first HARQ information and the payload size of the second HARQ information. In the mapping relationship between the PUCCH resource set and the load size, the PUCCH resource set corresponding to the sum of the load sizes of the above two HARQ information is determined, which is called the target PUCCH resource set. The PRI in the last DCI in the time domain position in a group of DCIs may be used to indicate a specific PUCCH resource in the PUCCH resource set. The UE may determine a PUCCH resource for transmitting the first HARQ information and the second HARQ information in the target PUCCH resource set according to the PRI of the last DCI in the time domain in a group of DCIs, that is, the above-mentioned first PUCCH resource. Optionally, each PUCCH resource set includes a maximum of 8 PUCCH resources. The PRI in the DCI can occupy 3 bits, and the above 3 bits can be used to indicate a specific PUCCH resource in the PUCCH resource set. The PUCCH resources may include time-domain symbols and frequency resource blocks (resource block, RB) occupied by the PUCCH in the uplink time slot.

It should be noted that in the above description, how the UE determines the PUCCH resource for the first HARQ information and the second HARQ information is used as an example to describe. In an actual transmission process, the UE may determine a PUCCH resource, and send the first HARQ information and the second HARQ information on the PUCCH resource. The base station may determine the PUCCH resource in a manner similar to the above, and receive the first HARQ information and the second HARQ information on the PUCCH resource. For example, the base station can determine the target PUCCH resource set according to the sum of the load sizes of the first HARQ information and the second HARQ information; according to the PRI of the DCI with the last time domain position in a group of DCIs, in the target PUCCH resource set, determine to receive PUCCH resources for the first HARQ information and the second HARQ information, and receive the first HARQ information and the second HARQ information on the PUCCH resources.

In another design, the UE may determine a target PUCCH resource set from a preset PUCCH resource set according to the payload size (payload size) of the first HARQ information and the payload size of the second HARQ information, and the target PUCCH resource set including at least one PUCCH resource;

If the first DCI does not schedule the PDSCH, and only the first DCI in the set of DCIs indicates that the UE retransmits the first HARQ information, and the first HARQ information indicated by the first DCI is invalid, then according to the set In the DCI except the first DCI, the PRI of the DCI with the last time domain position except the first DCI determines the second PUCCH resource in the target PUCCH resource set; the UE sends the first HARQ information to the base station through the second PUCCH resource and second HARQ information.

If the first DCI does not schedule the PDSCH, and only the first DCI in the group of DCIs instructs the UE to retransmit the first HARQ information, and the first HARQ information indicated by the first DCI is valid, then according to the first DCI The PRI determines the third PUCCH resource in the target PUCCH resource set; the UE sends the first HARQ information and the second HARQ information to the base station through the third PUCCH resource.

In this application, the invalidity may mean that the base station indicates through the first DCI the position of an uplink time slot where the canceled HARQ-ACK exists, but the UE does not find the HARQ-ACK codebook to be retransmitted on this uplink time slot (HARQ-ACK codebook used to bear the first HARQ-ACK information). It may be due to reasons such as missing DCI detection, the UE has never generated this codebook. The validity here may be that the first DCI indicates the position of the uplink time slot, and the UE finds the canceled HARQ-ACK codebook at the position of the uplink time slot.

In one design, for the HARQ-ACK codebook of type 2: the method for the base station to determine the payload size of the first HARQ information and the payload size of the second HARQ information may include: the base station determines that in a group of DCI corresponding to the first HARQ information The number of included DCIs, each DCI schedules a PDSCH, each PDSCH corresponds to a piece of HARQ information, each HARQ information occupies 1 bit, and the number of DCIs included in this group of DCIs is the payload size of the first HARQ information. As shown in FIG. 2, the DCI 0 corresponding to the first HARQ information is a group of DCIs, including 5 DCIs, and the payload size of the first HARQ information may be 5. Similarly, the base station may determine the payload size of the second HARQ information according to the number of DCIs included in the set of DCIs in step 500 above.

A manner for the UE to determine the load size of the first HARQ information and the second HARQ information may include: in one design, the first DCI may further indicate the load size of the first HARQ information. The UE may determine the load size of the first HARQ information according to the indication of the first DCI. Alternatively, it can be seen from the foregoing that the first HARQ information was previously canceled by the UE for some reason, and the specific content and payload size of the first HARQ information can be known to the UE, and the UE can use the previously stored first HARQ information, determining the load size of the first HARQ information and so on. For example, before canceling the transmission of the first HARQ information, the UE determines that the first HARQ information is specifically (ACK, ACK, NACK). Because in specific transmission, ACK and NACK can be represented by 1 and 0 respectively, each occupying 1 bit. The UE may determine that the payload size of the first HARQ information is 3. In this solution, it may be affected by missed detection of DCI, so that the determined first HARQ information lacks a certain bit, and the load size of the first HARQ information determined based on this method may not be accurate.

Since each DCI in a group of DCIs in step 500 above schedules one PDSCH, one PDSCH corresponds to one HARQ message, and each HARQ message is specifically NACK or ACK, each occupying 1 bit. Therefore, the payload size of the second HARQ information may be equal to the number of DCIs included in the group of DCIs. For example, a set of DCIs includes 5 DCIs, and the 5 DCIs respectively instruct the UE to receive PDSCH 1 to PDSCH 5, and to send the HARQ information of the above 5 PDSCHs. At this time, the payload size of the second HARQ information is 5.

Exemplarily, for the HARQ-ACK codebook of type 1: the method for the base station to determine the load size of the first HARQ information may include: the base station also determines the composition of the first HARQ information according to the first time domain position set (that is, the aforementioned K1 set). Corresponding PDSCH; if more than one PDSCH needs to feed back HARQ information, the first HARQ information is a complete type 1 codebook; if only one PDSCH needs to feed back HARQ information, that is, only one DCI schedules PDSCH, then the first HARQ The information is 1bit. Similarly, the base station may also determine the load size of the second HARQ information according to the first time domain position set.

In one design, the manner in which the UE determines the load size of the first HARQ information and the second HARQ information may include: the first DCI may further indicate the load size of the first HARQ information. For example, it indicates whether the payload size of the first HARQ information is 1 bit or a complete type 1 codebook size. The UE may determine the load size of the first HARQ information according to the indication of the first DCI. Alternatively, it can be seen from the foregoing that the first HARQ information was previously canceled by the UE for some reason, and the specific content and payload size of the first HARQ information can be known to the UE, and the UE can use the previously stored first HARQ information, determining the load size of the first HARQ information and so on.

In one design, the foregoing first HARQ information and the second HARQ information may be encoded independently. After the first HARQ information and the second HARQ information are encoded, they may be mapped to PUCCH resources for transmission. The PUCCH resource can be divided into at least one group of time-frequency resources according to the distance from a demodulation reference signal (demodulation reference signal, DMRS). The UE may first map the encoded bit sequence of the second HARQ information to the PUCCH resource according to the size of at least one group of time-frequency resource indexes, and then map the encoded bit sequence of the first HARQ information to the PUCCH resource. It can also be understood that the encoded bit sequence of the first HARQ information is concatenated after the encoded bit sequence of the second HARQ information. This is based on the consideration that the retransmitted first HARQ information should not affect the reception of the normally transmitted second HARQ information. For example, as shown in FIG. 6 , the PUCCH resources include 10 time-domain symbols, with indexes ranging from 0 to 9 in sequence, and each time-domain symbol includes 10 time-frequency resources. Time-domain symbol 2 and time-domain symbol 7 are DMRS symbols, which can be referred to the black filled part in FIG. 7 . The two groups of time-frequency resources closest to the DMRS symbols, or the time-frequency resources separated by 1 symbol from the DMRS symbols, are called the first group of time-frequency resources (see the hatched part in Figure 7), and the rest are The second group of time-frequency resources (see the unfilled part in FIG. 7 ). When the first HARQ information and the second HARQ information are mapped to PUCCH resources, the UE may first map the second HARQ information and then map the first HARQ information according to the sequence of the first group of time-frequency resources and the second group of time-frequency resources, That is, after the second HARQ information is mapped, the first HARQ information is mapped again.

In another design, the first HARQ information and the second HARQ information may be concatenated into one HARQ codebook. At this time, the UE may jointly encode the first HARQ information and the second HARQ information. The first DCI may indicate the load size of the first HARQ information, so as to prevent the reception of the second HARQ information by the base station from being affected by the inaccuracy of the load size of the first HARQ information.

For the process shown in Figure 5 above, the embodiment of the present application provides an application scenario: as shown in Figure 2, the base station sends DCI 0 and DCI 1 to the UE, since the PUCCH 0 indicated by DCI 0 is identical to the PUCCH 1 indicated by DCI 1 If there is a conflict, and the priority of the HARQ information corresponding to the PDSCH scheduled by DCI 0 is lower than the priority of the HARQ information corresponding to the PDSCH scheduled by DCI 1, the UE cancels sending the corresponding HARQ information on PUCCH 0, and the HARQ information that should be cancelled. It may be referred to as the first HARQ information in the process shown in FIG. 5 above. When the base station decides to retransmit the first HARQ information, a set of DCIs may be determined, and at least one DCI in the set of DCIs carries an indication to retransmit the first HARQ information. The indication to retransmit the first HARQ information may be an implicit indication. For example, an existing bit field in the DCI may be used to implicitly indicate whether the UE retransmits the first HARQ information or the like. Alternatively, show directions. For example, a new bit field may be added in the DCI, and the value of the bit field is the first value, for example, when 1, the UE may be instructed to retransmit the first HARQ information; or, the value of the bit field is the second value, For example, when 0, the UE may be instructed not to retransmit the first HARQ information, etc.; or, according to whether the bit field exists to indicate whether to retransmit the first HARQ information, when the bit field exists, the UE is instructed to retransmit the first HARQ information, When the bit field does not exist, the UE is not instructed to retransmit the first HARQ information.

It should be noted that there is no limitation on the time when the base station decides to retransmit the first HARQ information, but the time when the base station decides to retransmit the first HARQ information must be later than the time when the base station knows that the first HARQ message is canceled before transmission. The earliest time when the base station knows that the first HARQ information is canceled may be the time when the base station sends DCI 1 in FIG. 2 . When the base station sends DCI 1, the DCI indicates PUCCH 1. The base station knows that the HARQ information corresponding to PUCCH 1 indicated by DCI 1 will cancel the HARQ information corresponding to PUCCH 0 previously scheduled by DCI 0, but for some reason, the base station still sends DCI 1.

Example 1, the first DCI is the DCI with the last time domain position in the group of DCIs.

As shown in Figure 7, due to the conflict between PUCCH 0 and PUCCH 1, the UE cancels the transmission of the HARQ information corresponding to PUCCH 0. The base station may send a group of DCIs to the UE, and the group of DCIs includes 5 DCIs, which may be respectively referred to as the first DCI to the fifth DCI according to the sequence in the time domain. The HARQ information corresponding to the PDSCH scheduled by the first DCI to the fifth DCI is combined into the second HARQ information. The fifth DCI also instructs the UE to retransmit the first HARQ information. The above-mentioned fifth DCI may be referred to as the first DCI in step 500 .

In the above example 1, only one DCI in a group of DCIs is used to instruct the UE to retransmit the first HARQ information, which can save signaling overhead of the DCI.

Example 2, at least one DCI in the above step 500 includes at least two DCIs to instruct the UE to retransmit the first HARQ information. The at least two DCIs are continuous or discontinuous DCIs in the time domain, which is not limited.

In one design, multiple DCIs consecutive in time domain may be used in a group of DCIs to instruct the UE to retransmit the first HARQ information. Optionally, it may be N consecutive DCIs with lower time domain positions in a group of DCIs.

For example, as shown in Figure 8, since PUCCH 0 collides with PUCCH 1, the UE cancels sending HARQ information on PUCCH 0. The base station sends a group of DCIs to the UE, and the group of DCIs includes 5 DCIs, which are respectively referred to as the first DCI to the fifth DCI according to the receiving sequence in time. In the third DCI, the fourth DCI and the fifth DCI, the UE may be instructed to retransmit the first HARQ information.

In this design, since the possibility of multiple DCIs being lost at the same time is very small, the reliability of the indication can be enhanced by adopting the manner in which multiple DCIs simultaneously instruct the UE to retransmit the first HARQ information.

The above N is explained as follows: In a special design, the value of N above can be equal to the number of DCIs included in the set of DCIs, that is, each DCI in the set of DCIs instructs the UE to retransmit the first HARQ information . It should be noted that the above value of N is less than or equal to the number of DCIs included in the group of DCIs.

Or, in another design, multiple DCIs with discontinuous time domains may be used in a group of DCIs to instruct the UE to retransmit the first HARQ information.

As shown in Figure 9, due to the conflict between PUCCH 0 and PUCCH 1, the UE cancels the sending of HARQ information on PUCCH 0. The base station sends a group of DCIs to the UE, and the group of DCIs includes 5 DCIs, which are respectively referred to as the first DCI to the fifth DCI in sequence in the time domain. The base station may instruct the UE to retransmit the above-mentioned canceled HARQ information in the first DCI and the third DCI.

In this design, on the one hand, it is considered that multiple DCIs carry indications of retransmission HARQ information, which can enhance indication reliability. On the other hand, if the above indication of retransmission of the first HARQ information requires a 1-bit field to be implemented, then the above-mentioned DCI not indicating retransmission of the first HARQ information can omit the 1-bit field, saving DCI signaling overhead.

It should be noted that a special case may be included in this design that the DCI indicating retransmission of the first HARQ information in a group of DCIs does not include the last DCI in the group of DCIs.

It has been described above that, for the DCI instructing the UE to retransmit the first HARQ information, the payload size of the first HARQ information may also be indicated. The UE may send the first HARQ information to the base station based on the load size of the first HARQ information. Optionally, by adopting the above method, inaccurate payload size of the first HARQ information can be avoided from affecting reception of the second HARQ information.

For the type 2 HARQ-ACK codebook, for example, refer to any schematic diagram in FIG. 7 to FIG. 9 , DCI0 may include multiple DCIs. Among the multiple DCIs, especially the last DCI, if a missed detection occurs, the UE may not be able to detect it. In this way, the size of the first HARQ information determined by the UE is likely to be wrong. For example, DCI 0 specifically includes 4 DCIs, and the indexes are 1 to 4 in sequence. In the case of no missed detection, the first HARQ information determined by the UE is specifically (AN, AN, AN, AN), where AN represents ACK or NACK. If DCI3 is missed, and the UE can find it through the C-TAI carried by the DCI, the UE can fill in the HARQ corresponding to the missed DCI with NACK, and the first HARQ information determined by the UE can be (AN, AN, N, AN), N means NACK. However, if the DCI4 is missed and the UE does not detect the C-TAI carried by the DCI, the first HARQ information determined by the UE is (AN, AN, AN). If the UE sends the first HARQ information to the base station according to the load size of the above-mentioned wrong first HARQ information. The understanding of the load size of the first HARQ information by the base station and the UE is inconsistent. The base station thinks that the size of the first HARQ information should be 4 bits, and the payload size of the first HARQ information sent by the UE is 3 bits. Then it may cause interference to other transmitted UCI, such as the second HARQ information. In this embodiment of the present application, the DCI is used to indicate the load size of the first HARQ information, which can make the understanding of the size of the first HARQ information consistent between the base station and the UE, and avoid affecting the transmission of the second HARQ information.

In one design, after the UE acquires the payload size of the first HARQ information indicated by the DCI, the UE may compare the payload size of the first HARQ information indicated by the DCI with the payload size of the HARQ information determined by the UE according to the aforementioned DCI. If the two are consistent, it is considered that the UE does not miss detection of DCI. The UE directly transmits the previously canceled HARQ information, that is, the first HARQ information, to the base station. If the two are inconsistent, it is considered that the UE missed DCI before, and the HARQ information corresponding to the missed DCI can be supplemented according to the load size of the first HARQ information indicated by the DCI. Using the above example, the UE missed the last DCI, and the determined first HARQ information is (AN, AN, AN). The load size of the first HARQ information indicated by the DCI is 4, then the UE can fill in 1-bit NACK in the first HARQ information of the above-mentioned determined 3 load sizes, and the first HARQ information after filling can be (AN, AN , AN, N). The UE sends the supplemented HARQ information to the base station.

It should be noted that the scheme of indicating the payload size of the first HARQ information in the above-mentioned first DCI and the above-mentioned scheme of concatenating the encoded bit sequence of the first HARQ information after the encoded bit sequence of the second HARQ information can be considered as Two parallel programs. The two schemes can prevent the retransmitted first HARQ information from causing interference to the normally transmitted second HARQ information. Certainly, the above two solutions may be used independently or in combination, without limitation.

Optionally, a DAI may be set in the DCI, and the value of the DAI may be used to indicate the payload size of the first HARQ information. The DAI field may occupy 2 bits, or other more bits, etc., which are not limited. For example, in the current solution, the DCI may include a C-DAI, and the C-DAI may indicate the C-DAI of the DCI corresponding to the second HARQ information. In the case of multiple carriers, the DCI may further include a T-DAI, where the T-DAI is used to indicate that the second HARQ information corresponds to the T-DAI of the DCI. In this embodiment of the present application, a DAI value may be additionally set in the DCI, and the DAI value may indicate the payload size of the retransmitted first HARQ information. Specifically, the base station may calculate the remainder of X modulo 4 according to the load size X of the first HARQ information, and the values of the remainder are 1, 2, 3 and 0 respectively corresponding to 00, 01, 10 and 11 of the 2-bit DAI .

For example, the correct payload size of the first HARQ message is 2. The base station sends a group of DCIs to the UE, and the group of DCIs includes 5 DCIs. Instructing the UE to retransmit the load size of the first HARQ information for the first DCI and the third DCI in the group of DCIs. Then, the first DCI and the third DCI may include an additional DAI field, and the value of the DAI is 01. For other DCIs in the set of DCIs, this extra DAI field may not be included. Alternatively, the UE is instructed to retransmit the first HARQ information for the third DCI in the group of DCIs, then the third DCI in the group of DCIs includes the above-mentioned additional DAI field, and the value of the DAI is 01. Other DCIs in this set of DCIs do not include the above-mentioned DAI field.

For type 1 HARQ-ACK codebook: For the canceled HARQ codebook type is type 1, if the base station schedules 2 PDSCHs through 2 DCIs, corresponding to 2-bit HARQ feedback, UE will feed back a complete set of type 1 HARQ codebooks ; However, if the UE misses a DCI, the UE will only consider it as a 1-bit HARQ feedback, which will cause the HARQ codebook size to be ambiguous when the UE misses a DCI. If the initial transmission codebook and the retransmission codebook are cascaded together for transmission, the size of the retransmission codebook will be ambiguous, which will affect the performance of the initial transmission codebook.

In one design, the first DCI does not schedule data, and uses a 1-bit field to indicate the payload size of the first HARQ information. Specifically, a value of 0 in this 1-bit field indicates that the size of the first HARQ information is 1 bit. 1 indicates that the first HARQ information is a complete type 1 HARQ codebook. The complete type 1 HARQ codebook is determined according to the K1 set.

It can be understood that, in order to implement the functions in the foregoing embodiments, the base station and the terminal include hardware structures and/or software modules corresponding to each function. Those skilled in the art should easily realize that the present application can be implemented in the form of hardware or a combination of hardware and computer software with reference to the units and method steps of the examples described in the embodiments disclosed in the present application. Whether a certain function is executed by hardware or computer software drives the hardware depends on the specific application scenario and design constraints of the technical solution.

FIG. 10 and FIG. 11 are schematic structural diagrams of possible communication devices provided by the embodiments of the present application. These communication devices can be used to implement the functions of the terminal or the base station in the above method embodiments, and therefore can also realize the beneficial effects of the above method embodiments. In the embodiment of the present application, the communication device may be one of the terminals 120a-120j shown in FIG. 1, or the base station 110a or 110b shown in FIG. 1, or a terminal or a base station Modules (such as chips).

As shown in FIG. 10 , a communication device 1000 includes a processing unit 1010 and a transceiver unit 1020 . The communication device 1000 is configured to implement the functions of a terminal or a base station in the method embodiment shown in FIG. 5 above.

When the communication device 1000 is used to implement the functions of the terminal in the method embodiment shown in FIG. 5: the transceiver unit 1020 is used to receive a set of DCIs from the network equipment, and the first DCI in the set of DCIs also indicates that the terminal The device retransmits first HARQ information; the processing unit 1010 is configured to determine the first HARQ information; the transceiver unit 1020 is configured to send the first HARQ information to the network device.

When the communication device 1000 is used to implement the functions of the base station in the method embodiment shown in FIG. 5: the transceiver unit 1020 is used to send a set of DCIs to the terminal equipment, and the first DCI in the set of DCIs also indicates that the terminal equipment retransmitting first HARQ information, and receiving the first HARQ information from the terminal device. The processing unit 1010 is configured to process the first HARQ information.

More detailed descriptions about the processing unit 1010 and the transceiver unit 1020 can be directly obtained by referring to related descriptions in the method embodiment shown in FIG. 5 , and details are not repeated here.

As shown in FIG. 11 , a communication device 1100 includes a processor 1110 and an interface circuit 1120 . The processor 1110 and the interface circuit 1120 are coupled to each other. It can be understood that the interface circuit 1120 may be a transceiver or an input-output interface. Optionally, the communication device 1100 may further include a memory 1130 for storing instructions executed by the processor 1110 or storing input data required by the processor 1110 to execute the instructions or storing data generated by the processor 1110 after executing the instructions.

When the communication device 1100 is used to implement the method shown in FIG. 5 , the processor 1110 is used to implement the functions of the above-mentioned processing unit 1010 , and the interface circuit 1120 is used to implement the functions of the above-mentioned transceiver unit 1020 .

When the above communication device is a chip applied to a terminal, the terminal chip implements the functions of the terminal in the above method embodiment. The terminal chip receives information from other modules in the terminal (such as radio frequency modules or antennas), and the information is sent to the terminal by the base station; or, the terminal chip sends information to other modules in the terminal (such as radio frequency modules or antennas), and the The information is sent by the terminal to the base station.

When the above communication device is a module applied to a base station, the base station module implements the functions of the base station in the above method embodiment. The base station module receives information from other modules in the base station (such as radio frequency modules or antennas), and the information is sent to the base station by the terminal; or, the base station module sends information to other modules in the base station (such as radio frequency modules or antennas), the The information is sent by the base station to the terminal. The base station module here may be a baseband chip of the base station, or a DU or other modules, and the DU here may be a DU under an open radio access network (O-RAN) architecture.

It can be understood that the processor in the embodiments of the present application may be a central processing unit (central processing unit, CPU), and may also be other general processors, digital signal processors (digital signal processor, DSP), application specific integrated circuits (application specific integrated circuit, ASIC), field programmable gate array (field programmable gate array, FPGA) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. A general-purpose processor can be a microprocessor, or any conventional processor.

The method steps in the embodiments of the present application may be implemented by means of hardware, or may be implemented by means of a processor executing software instructions. Software instructions can be composed of corresponding software modules, and software modules can be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only Memory, registers, hard disk, removable hard disk, CD-ROM or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such the processor can read information from, and write information to, the storage medium. Of course, the storage medium may also be a component of the processor. The processor and storage medium can be located in the ASIC. In addition, the ASIC can be located in the base station or the terminal. Certainly, the processor and the storage medium may also exist in the base station or the terminal as discrete components.

In the above embodiments, all or part of them may be implemented by software, hardware, firmware or any combination thereof. When implemented using software, it may be implemented in whole or in part in the form of a computer program product. The computer program product comprises one or more computer programs or instructions. When the computer program or instructions are loaded and executed on the computer, the processes or functions described in the embodiments of the present application are executed in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, network equipment, user equipment, or other programmable devices. The computer program or instructions can be stored in or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer program or instructions can be downloaded from a website, computer, A server or data center transmits to another website site, computer, server or data center by wired or wireless means. The computer-readable storage medium may be any available medium that can be accessed by a computer, or a data storage device such as a server or a data center integrating one or more available media. The available medium may be a magnetic medium, such as a floppy disk, a hard disk, or a magnetic tape; it may also be an optical medium, such as a digital video disk; or it may be a semiconductor medium, such as a solid-state hard disk. The computer readable storage medium may be a volatile or a nonvolatile storage medium, or may include both volatile and nonvolatile types of storage media.

In each embodiment of the present application, if there is no special explanation and logical conflict, the terms and/or descriptions between different embodiments are consistent and can be referred to each other, and the technical features in different embodiments are based on their inherent Logical relationships can be combined to form new embodiments.

Optional according to the specification: In this application, "at least one" refers to one or more, and "multiple" refers to two or more. "And/or" describes the association relationship of associated objects, indicating that there can be three types of relationships, for example, A and/or B, which can mean: A exists alone, A and B exist at the same time, and B exists alone, where A, B can be singular or plural. In the text description of this application, the character "/" generally indicates that the contextual objects are an "or" relationship; in the formulas of this application, the character "/" indicates that the contextual objects are a "division" Relationship. "Including at least one of A, B and C" may mean: including A; including B; including C; including A and B; including A and C; including B and C; including A, B and C.

It can be understood that the various numbers involved in the embodiments of the present application are only for convenience of description, and are not used to limit the scope of the embodiments of the present application. The size of the serial numbers of the above-mentioned processes does not mean the order of execution, and the execution order of each process should be determined by its functions and internal logic.

Claims (19)

1. A method for retransmitting feedback information, applied to a terminal device, characterized in that it includes:

   Receive a set of downlink control information DCI from the network device, where the first DCI in the set of DCI instructs the terminal device to retransmit the first Hybrid Automatic Repeat Request (HARQ) information;

   Send the first HARQ information to the network device.
2. The method according to claim 1, wherein the first DCI includes a first field, the first field is a field of a reusable scheduled Physical Downlink Shared Channel (PDSCH), and the first field is used to indicate the configuration information of the first HARQ information.
3. The method according to claim 1 or 2, wherein only the first DCI in the set of DCI instructs the terminal device to retransmit the first HARQ information.
4. The method according to claim 3, wherein, except for the first DCI in the group of DCIs, each of the other DCIs schedules a PDSCH respectively, and the method further comprises:

   Sending second HARQ information to the network device, where the second HARQ information includes HARQ feedback information of PDSCHs scheduled by other DCIs in the group of DCIs except the first DCI.
5. The method according to claim 4, wherein the sending the first HARQ information and the second HARQ information to the network device comprises:

   According to the load size of the first HARQ information and the load size of the second HARQ information, determine a target PUCCH resource set from a preset physical uplink control channel PUCCH resource set, where the target PUCCH resource set includes at least one PUCCH resource;

   Determine the first PUCCH resource in the target PUCCH resource set according to the PUCCH resource indication PRI of the DCI with the last time domain position in the group of DCIs;

   Sending the first HARQ information and the second HARQ information to the network device through the first PUCCH resource.
6. The method according to claim 4, wherein the sending the first HARQ information and the second HARQ information to the network device comprises:

   Determine a target PUCCH resource set from a preset PUCCH resource set according to the load size of the first HARQ information and the load size of the second HARQ information, where the target PUCCH resource set includes at least one PUCCH resource;

   Only the first DCI in the set of DCI instructs the terminal device to retransmit the first HARQ information, and the first HARQ information indicated by the first DCI is invalid, then according to the set of DCI In addition to the first DCI, the PRI of the DCI with the last time domain position in the target PUCCH resource set determines the second PUCCH resource;

   Sending the first HARQ information and the second HARQ information to the network device through the second PUCCH resource.
7. The method according to claim 4, wherein the sending the first HARQ information and the second HARQ information to the network device comprises:

   Determine a target PUCCH resource set from a preset PUCCH resource set according to the load size of the first HARQ information and the load size of the second HARQ information, where the target PUCCH resource set includes at least one PUCCH resource;

   Only the first DCI in the set of DCI instructs the terminal device to retransmit the first HARQ information, and the first HARQ information indicated by the first DCI is valid, then according to the first DCI PRI, in the target PUCCH resource set, determine a third PUCCH resource;

   Sending the first HARQ information and the second HARQ information to the network device through the third PUCCH resource.
8. The method according to any one of claims 1 to 7, wherein the first DCI also indicates a payload size of the first HARQ information.
9. A method for retransmitting feedback information, applied to network equipment, characterized in that it includes:

   Sending a set of downlink control information DCI to the terminal device, where the first DCI in the set of DCI instructs the terminal device to retransmit the first hybrid automatic repeat request HARQ information;

   The first HARQ information is received from the terminal device.
10. The method according to claim 9, wherein the first DCI includes a first field, the first field is a field of a reusable scheduled Physical Downlink Shared Channel (PDSCH), and the first field is used to indicate the configuration information of the first HARQ information.
11. The method according to claim 9 or 10, wherein only the first DCI in the group of DCI instructs the terminal device to retransmit the first HARQ information.
12. The method according to claim 11, wherein, except for the first DCI in the group of DCIs, each DCI in the other DCIs schedules a PDSCH respectively, and the method further comprises:

    receiving second HARQ information from the terminal device, where the second HARQ information includes HARQ feedback information of PDSCHs scheduled by other DCIs in the group of DCIs except the first DCI.
13. The method according to claim 12, wherein the receiving the first HARQ information and the second HARQ information from the terminal device comprises:

    According to the load size of the first HARQ information and the load size of the second HARQ information, determine a target PUCCH resource set from a preset physical uplink control channel PUCCH resource set, and the target PUCCH resource set includes at least one PUCCH resource ;

    Determine the first PUCCH resource in the target PUCCH resource set according to the PUCCH resource indication PRI of the DCI with the last time domain position in the group of DCIs;

    Receive the first HARQ information and the second HARQ information from the terminal device through the first PUCCH resource.
14. The method according to claim 12, wherein the receiving the first HARQ information and the second HARQ information from the terminal device comprises:

    Determine a target PUCCH resource set from a preset PUCCH resource set according to the load size of the first HARQ information and the load size of the second HARQ information, where the target PUCCH resource set includes at least one PUCCH resource;

    Only the first DCI in the set of DCI instructs the terminal device to retransmit the first HARQ information, and the first HARQ information indicated by the first DCI is invalid, then according to the set of DCI In addition to the first DCI, the PRI of the DCI with the last time domain position in the target PUCCH resource set determines the second PUCCH resource;

    Receive the first HARQ information and the second HARQ information from the terminal device through the second PUCCH resource.
15. The method according to claim 12, wherein the receiving the first HARQ information and the second HARQ information from the terminal device comprises:

    Determine a target PUCCH resource set from a preset PUCCH resource set according to the load size of the first HARQ information and the load size of the second HARQ information, where the target PUCCH resource set includes at least one PUCCH resource;

    Only the first DCI in the set of DCI instructs the terminal device to retransmit the first HARQ information, and the first HARQ information indicated by the first DCI is valid, then according to the first DCI PRI, in the target PUCCH resource set, determine a third PUCCH resource;

    Receive the first HARQ information and the second HARQ information from the terminal device through the third PUCCH resource.
16. The method according to any one of claims 9 to 15, wherein the first DCI also indicates the payload size of the first HARQ information.
17. A communication device, characterized by comprising a unit for performing the method according to any one of claims 1 to 8, or a unit for performing the method according to any one of claims 9 to 16 .
18. A communication device, characterized in that it includes a processor and an interface circuit, the interface circuit is used to receive signals from other communication devices other than the communication device and transmit them to the processor or transfer signals from the processor The signal is sent to other communication devices other than the communication device, and the processor implements the method according to any one of claims 1 to 8 through a logic circuit or executes code instructions, or is used to realize the method described in any one of claims 1 to 8 The method described in any one of 9 to 16 is required.
19. A computer-readable storage medium, characterized in that computer programs or instructions are stored in the storage medium, and when the computer programs or instructions are executed by a communication device, the implementation of any one of claims 1 to 8 method, or implement the method as described in any one of claims 9 to 16.

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