CN115333592A

CN115333592A - Feedback method of channel state information and communication device

Info

Publication number: CN115333592A
Application number: CN202110904382.0A
Authority: CN
Inventors: 李锐杰; 官磊; 李胜钰
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-05-10
Filing date: 2021-08-06
Publication date: 2022-11-11

Abstract

The application discloses a CSI feedback method and a communication device, wherein the method comprises the following steps: the method includes determining first CSI, and transmitting first information to a network device. Wherein the first information is used for indicating an offset value used for indicating a difference value between a first reference value and the first CSI; alternatively, the offset value is used to indicate a difference between the first CSI and the first reference value. After the terminal device obtains the first CSI, an offset value relative to the first CSI is fed back to the network device. That is, the terminal device only needs to report the difference between the first CSI and the first reference value, that is, the offset value. The network has less bit occupation compared with the method of directly feeding back the first CSI because the terminal equipment feeds back the deviant, thereby saving the feedback overhead. In addition, since the network device and the terminal device understand the first reference value consistently, the first CSI determined by the network device is the first CSI fed back by the terminal device, so that the accuracy of the CSI fed back by the terminal device can be improved.

Description

Feedback method of channel state information and communication device

The present application claims priority of chinese patent application with application number 202110507937.8, entitled "a feedback method of channel state information and communication apparatus" filed by chinese patent office at 10/05/2021, the entire contents of which are incorporated herein by reference.

Technical Field

The present application relates to the field of communications technologies, and in particular, to a method for feeding back Channel State Information (CSI) and a communications apparatus.

Background

In order to save more overhead, the terminal device may feed back CSI, for example, when a Channel Quality Indicator (CQI) or a Modulation and Coding Scheme (MCS) is fed back, an offset (offset) of the CSI with respect to a reference value (may also be referred to as a reference value) may be fed back. If the selection of the reference value is proper, for example, the channel state information measured by the terminal equipment can fluctuate in a small range around the reference value, so that more accurate channel state information can be fed back by using fewer bits (bits). However, if the selection of the reference value is not appropriate, more bits are needed to feed back the prepared channel state information, and the effect of saving overhead cannot be achieved. Alternatively, if the reference value is not selected properly, a large error of CSI may result. Therefore, how to select an appropriate reference value is an urgent problem to be solved.

Disclosure of Invention

The application provides a CSI feedback method and a communication device, which are used for improving the accuracy of CSI feedback while saving feedback overhead.

In a first aspect, a CSI feedback method is provided, which may be performed by a first communication apparatus, which may be a communication device or a communication apparatus capable of supporting the communication device to implement functions required by the method, such as a chip system. The following description will be given taking the communication device as a terminal device as an example. The method comprises the following steps:

the method includes determining first CSI, and transmitting first information to a network device. Wherein the first information is used for indicating an offset value used for indicating a difference value between a first reference value and the first CSI; alternatively, the offset value is used to indicate a difference between the first CSI and the first reference value. It is to be appreciated that the first CSI may indicate one or more of a modulation scheme, a coding rate, and a spectral efficiency. In the embodiment of the present application, after the terminal device measures the channel and obtains the channel state information, that is, the first CSI, an offset value relative to the first CSI may be fed back to the network device. For example, a reference value, for example, a first reference value may be determined, and the terminal device only needs to report a difference value between the first CSI and the first reference value, that is, an offset value. Alternatively, the terminal device may determine an offset value, which is a difference between the first CSI and the first reference value, or an offset value, which is a difference between the first reference value and the first CSI. And the terminal equipment feeds back the first CSI to the network equipment, and only the offset value needs to be reported. The network equipment can determine the first CSI fed back by the terminal equipment according to the offset value and the first reference value. Since the terminal device feeds back the offset value, compared with the method of directly feeding back the first CSI, the method occupies fewer bits, and thus, feedback overhead is saved. In addition, since the network device and the terminal device understand the first reference value consistently, the first CSI determined by the network device is the first CSI fed back by the terminal device, that is, the accuracy of the CSI fed back by the terminal device can be ensured.

In the embodiment of the present application, the terminal device may determine a suitable first reference value, and there are multiple determination manners, which is specifically used, and the embodiment of the present application is not limited and is flexible.

Illustratively, the method further comprises: second information is received from the network device, the second information being used to determine the first reference value. This solution is that the network device sends second information for determining the first reference value to the terminal device, i.e. the terminal device may determine the first reference value based on an indication of the network device.

For example, the second information indicates the first reference value, i.e. the network device may directly indicate the first reference value, which is straightforward and simple, and the network device may indicate the reference value according to specific requirements, which is more flexible.

Alternatively, the second information indicates a second reference value, which is used to determine the first reference value. The solution, i.e. the network device, indicates the first reference value indirectly by indicating an intermediate value. By the network device indicating the intermediate value, the terminal device may determine the first reference value in combination with the other parameters and the indicated intermediate value. In this way, a more accurate first reference value can be obtained.

Alternatively, the second information indicates a first set of candidate values including a second reference value used for determining the first reference value. The scheme, i.e. the network device indication, comprises a set of second reference values. The terminal device determines the second reference value from the set and thereby further determines the first reference value. In this scheme, the set of candidate values is determined by the indication information. The terminal equipment can further determine the reference value through other information, and the method is more flexible.

Alternatively, the second information indicates a second set of candidate values, the second set of candidate values including the first reference value. The scheme, i.e. the network device indication, comprises a set of first reference values. The terminal device determines a first reference value from the set, in which case the set of candidate values is determined by means of the indication information. The terminal equipment can further determine the reference value through other information, and the method is more flexible.

Illustratively, the method further comprises: and determining second CSI which is used for determining the first reference value, wherein the second CSI is related to the first CSI. According to the scheme, the terminal equipment determines the first reference value based on the second CSI related to the first CSI, and signaling overhead can be saved without indication of the network equipment.

Wherein the second CSI satisfies at least one of:

the second CSI is the CSI closest to the first CSI in time before the reporting time of the first CSI; alternatively, the first and second electrodes may be,

the second CSI is a CSI closest to a Physical Downlink Shared Channel (PDSCH) in time before a PDSCH corresponding to the first CSI; alternatively, the first and second liquid crystal display panels may be,

a target block error rate (BLER) associated with the second CSI is the same as a target BLER used for the first CSI; alternatively, the first and second liquid crystal display panels may be,

the reportConfigId of the second CSI is associated with the reportConfigId of the first CSI, or the CSI-ResourceConfigId of the second CSI is associated with the CSI-ResourceConfigId of the first CSI, or the nzp-CSI-ResourceSetId of the second CSI is associated with the nzp-CSI-ResourceSetId of the first CSI.

In a possible implementation, the determining the first reference value by the second CSI includes:

determining a wideband CQI corresponding to the second CSI, wherein the wideband CQI is used for determining a first reference value; alternatively, the first and second electrodes may be,

determining a wideband CQI corresponding to the second CSI, wherein the wideband CQI is a second reference value Y which is used for determining a first reference value Y; alternatively, the first and second liquid crystal display panels may be,

the sub-band CQI corresponding to the second CSI and at least one sub-band CQI corresponding to the PDSCH corresponding to the first CSI are used for determining a first reference value.

Illustratively, determining the first CSI comprises: the first CSI is determined according to a target BLER, which is indicated by Downlink Control Information (DCI). In this scheme, the network device may dynamically instruct, through the DCI, the terminal device to calculate the target BLER to be used for the MCS corresponding to the PDSCH, which may be 10, for example ^-1 、10 ^-2 、10 ^-3 、10 ^-4 、10 ^-5 、10 ^-6 、10 ^-7 Or 10 ^-8 And the like. Because the target BLER to be adopted by the terminal equipment for calculating the MCS corresponding to the PDSCH is indicated by the network equipment, the target BLER adopted by the terminal equipment and the network equipment when determining the MCS corresponding to the PDSCH is the same, and the problem that the MCS determined by the terminal equipment and the network equipment has larger deviation because the target BLER adopted by the terminal equipment and the network equipment when determining the MCS corresponding to the PDSCH is different can be avoided.

In a possible implementation, determining the first CSI comprises:

receiving first indication information and/or second indication information, wherein the first indication information is used for indicating a first BLER, and the second indication information is used for indicating a second BLER; determining a target BLER, wherein the target BLER is a first BLER or a second BLER; and determining first CSI according to the target BLER.

In a possible implementation, determining the target BLER includes:

receiving first indication information, not receiving second indication information, and determining the target BLER as a first BLER; alternatively, the first and second liquid crystal display panels may be,

receiving second indication information, not receiving the first indication information, and determining the target BLER as a second BLER; alternatively, the first and second liquid crystal display panels may be,

and receiving the first indication information and the second indication information, and determining the target BLER as a second BLER.

In a possible implementation, the second indication information is DCI.

In a possible implementation manner, the first indication information is used for indicating a CQI index table, where the CQI index table is associated with one BLER; alternatively, the first indication information is used to indicate an MCS index table, and the MCS index table is associated with one BLER.

In a possible implementation, the first CSI is determined according to the first PDSCH, which is a retransmitted PDSCH.

In a possible implementation, the first reference value is determined according to the first PDSCH.

In a possible implementation, the determining of the first reference value according to the first PDSCH includes: the first reference value is determined according to the spectral efficiency corresponding to the first PDSCH.

In a possible implementation, the determining of the first reference value according to the first PDSCH includes: the first reference value is determined according to a modulation mode, TBS and/or time frequency resource size corresponding to the first PDSCH.

In a possible implementation manner, the first reference value is determined according to the second PDSCH, and the second PDSCH is the originally transmitted PDSCH corresponding to the first PDSCH.

In a possible implementation manner, the terminal device does not receive the first PDSCH corresponding to the first PDSCH, and the first information is used to indicate the first state, or the offset value is used to indicate the first state, where the first state is used to indicate that the terminal device cannot obtain the first CSI.

In a second aspect, corresponding to the first aspect, a feedback method of channel state information is provided, where the method may be performed by a second communication apparatus, and the second communication apparatus may be a communication device or a communication apparatus capable of supporting the communication device to implement functions required by the method, such as a system on a chip. The following description will be given taking the communication device as a network device as an example. The method comprises the following steps:

receiving first information, wherein the first information is used for indicating an offset value, and the offset value is used for indicating a difference value between a first reference value and first CSI;

determining the first CSI according to the offset value and the first reference value.

In a possible implementation, the method further comprises: and sending second information to the terminal equipment, wherein the second information is used for determining the first reference value.

In a possible implementation, the second information indicates the first reference value. Alternatively, the second information indicates a second reference value, which is used to determine the first reference value. Alternatively, the second information indicates a first set of candidate values including a second reference value used to determine the first reference value. Alternatively, the second information indicates a second set of candidate values, the second set of candidate values including the first reference value.

In a possible implementation, the first reference value is determined by second CSI, the second CSI being related to the first CSI.

In a possible implementation, the second CSI satisfies at least one of:

the second CSI is the CSI closest to the PDSCH in time before the PDSCH corresponding to the first CSI; alternatively, the first and second liquid crystal display panels may be,

the target BLER associated with the second CSI is the same as the target BLER adopted by the first CSI; alternatively, the first and second liquid crystal display panels may be,

the first reference value is determined by wideband CQI corresponding to the second CSI; alternatively, the first and second liquid crystal display panels may be,

the first reference value is determined by a second reference value determined by the second CSI corresponding to the wideband CQI; alternatively, the first and second electrodes may be,

the first reference value is determined by the sub-band CQI corresponding to the second CSI and at least one sub-band CQI corresponding to the PDSCH corresponding to the first CSI.

In a possible implementation, the method further comprises: and sending DCI to the terminal equipment, wherein the DCI is used for indicating target BLER, and the target BLER is used for determining the first CSI.

In a possible implementation, the method further comprises: and sending first indication information and/or second indication information to the terminal equipment, wherein the first indication information is used for indicating the first BLER, and the second indication information is used for indicating the second BLER.

In a possible implementation manner, the first indication information is used for indicating a CQI index table, and the CQI index table is associated with one BLER; alternatively, the first indication information is used to indicate an MCS index table, and the MCS index table is associated with one BLER.

In a possible implementation, the first CSI is determined according to the first PDSCH, and the first PDSCH is a retransmitted PDSCH.

In a possible implementation manner, the first reference value is determined according to the second PDSCH, and the second PDSCH is an initially transmitted PDSCH corresponding to the first PDSCH.

The beneficial effects of the second aspect and any possible implementation manner of the second aspect may refer to the beneficial effects of the foregoing first aspect and any possible implementation manner of the first aspect, and are not described herein again.

In a third aspect, a communication device is provided, where the communication device has a function of implementing the behavior in the method example of the first aspect, and for beneficial effects, reference may be made to the description of the first aspect and details are not repeated here. The functions can be realized by hardware, and the functions can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the above-described functions. In one possible design, the communication device includes: a processing module and/or a transceiver module. These modules may perform the corresponding functions in the above-described method examples of the first aspect.

Illustratively, the processing module is configured to determine the first CSI; the transceiver module is configured to send first information to the network device, where the first information is used to indicate an offset value. Wherein the offset value is used to indicate a difference between the first reference value and the first CSI; alternatively, the offset value is used to indicate a difference between the first CSI and the first reference value.

In a possible implementation manner, the transceiver module is further configured to: second information is received from the network device, the second information being used to determine the first reference value.

In one possible implementation, the second information indicates a first reference value; or, the second information indicates a second reference value, which may be used to determine the first reference value; or, the second information indicates a first candidate value set including a second reference value used for determining the first reference value; alternatively, the second information indicates a second set of candidate values including the first reference value.

In one possible implementation manner, the processing module is further configured to: determining second CSI for determining the first reference value, the second CSI being related to the first CSI.

In one possible implementation, the second CSI satisfies at least one of:

the second CSI is the CSI closest to the first CSI in time before the reporting time of the first CSI; or the second CSI is a CSI closest to the PDSCH in time before the PDSCH corresponding to the first CSI; or the target BLER related to the second CSI is the same as the target BLER adopted by the first CSI; or the ReportConfigId of the second CSI is associated with the ReportConfigId of the first CSI, or the CSI-resourceconconfigid of the second CSI is associated with the CSI-resourceconconfigid of the first CSI, or the nzp-CSI-resourcesetidid of the second CSI is associated with the nzp-CSI-resourcesetidid of the first CSI.

In a possible implementation manner, the determining the first reference value by the second CSI includes:

the second CSI corresponds to a wideband CQI used for determining the first reference value; or the second CSI corresponds to a wideband CQI, where the wideband CQI is a second reference value Y, and the second reference value is used to determine the first reference value Y; or the sub-band CQI corresponding to the second CSI and the at least one sub-band CQI corresponding to the PDSCH corresponding to the first CSI are used to determine the first reference value.

In a possible implementation manner, the processing module is specifically configured to: determining the first CSI based on a target BLER, wherein the target BLER is indicated by a DCI.

In a possible implementation, the transceiver module is further configured to: and receiving first indication information and/or second indication information, wherein the first indication information is used for indicating the first BLER, and the second indication information is used for indicating the second BLER. The processing module is specifically configured to determine a target BLER, where the target BLER is a first BLER or a second BLER; and determining a first CSI according to the target BLER.

In a possible implementation manner, the processing module is specifically configured to:

receiving second indication information, not receiving the first indication information, and determining the target BLER as a second BLER; alternatively, the first and second electrodes may be,

In a possible implementation, the second indication information is DCI.

The beneficial effects of the third aspect and any possible implementation manner of the third aspect may refer to the beneficial effects of the foregoing first aspect and any possible implementation manner of the first aspect, and are not described herein again.

In a fourth aspect, a communication apparatus is provided, where the communication apparatus has a function of implementing behaviors in the method example of the second aspect, and beneficial effects may be found in the description of the second aspect and are not described herein again. The functions can be realized by hardware, and the functions can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the functions described above. In one possible design, the communication device includes: a processing module and/or a transceiver module. These modules may perform the corresponding functions in the above-described method example of the second aspect.

Exemplarily, the transceiver module is configured to receive first information indicating an offset value indicating a difference between a first reference value and first CSI of the PDSCH;

the processing module is configured to determine the first CSI based on the offset value and the first reference value.

In one possible implementation, the transceiver module is further configured to: and sending second information to the terminal equipment, wherein the second information is used for determining the first reference value.

In one possible implementation, the second information indicates the first reference value; or the second information indicates a second reference value, which is used for determining the first reference value; or, the second information indicates a first candidate value set, the first candidate value set including a second reference value used to determine the first reference value; alternatively, the second information indicates a second set of candidate values, the second set of candidate values including the first reference value.

In one possible implementation, the first reference value is determined by second CSI, which is related to the first CSI.

In one possible implementation, the second CSI satisfies at least one of:

the second CSI is the CSI closest to the first CSI in time before the reporting time of the first CSI; or the second CSI is a CSI closest to the PDSCH in time before the PDSCH corresponding to the first CSI; or the target BLER associated with the second CSI is the same as the target BLER adopted by the first CSI; or the ReportConfigId of the second CSI is associated with the ReportConfigId of the first CSI, or the CSI-resourceConfigId of the second CSI is associated with the CSI-resourceConfigId of the first CSI, or the nzp-CSI-resourceSetId of the second CSI is associated with the nzp-CSI-resourceSetId of the first CSI.

In one possible implementation, the determining the first reference value by the second CSI includes:

the first reference value is determined by the wideband CQI corresponding to the second CSI; alternatively, the first and second electrodes may be,

In one possible implementation, the transceiver module is further configured to: and sending DCI to terminal equipment, wherein the DCI is used for indicating target BLER, and the target BLER is used for determining the first CSI.

In a possible implementation, the transceiver module is further configured to: and sending first indication information and/or second indication information to the terminal equipment, wherein the first indication information is used for indicating the first BLER, and the second indication information is used for indicating the second BLER.

In a possible implementation, the determining of the first reference value according to the first PDSCH includes: and the first reference value is determined according to a modulation mode, TBS and/or the size of time-frequency resources corresponding to the first PDSCH.

In a fifth aspect, a communication apparatus is provided, where the communication apparatus may be the terminal device in the above method embodiment, or a chip provided in the terminal device. The communication device comprises a communication interface, a processor and optionally a memory. Wherein the memory is adapted to store a computer program or instructions, and the processor is coupled to the memory and the communication interface, and when the processor executes the computer program or instructions, the communication apparatus is adapted to perform the method performed by the terminal device in the above-mentioned method embodiments.

In a sixth aspect, a communication apparatus is provided, where the communication apparatus may be the network device in the above method embodiment, or a chip disposed in the network device. The communication device comprises a communication interface, a processor and optionally a memory. Wherein the memory is used for storing a computer program or instructions, and the processor is coupled with the memory and the communication interface, and when the processor executes the computer program or instructions, the communication device is caused to execute the method executed by the network device in the method embodiment.

In a seventh aspect, a computer program product is provided, the computer program product comprising: computer program code which, when run, causes the method performed by the terminal device in the above aspects to be performed.

In an eighth aspect, there is provided a computer program product comprising: computer program code which, when executed, causes the method performed by the network device in the above aspects to be performed.

In a ninth aspect, the present application provides a chip system, which includes a processor, and is configured to implement the functions of the terminal device in the methods of the above aspects. In one possible design, the system-on-chip further includes a memory to store program instructions and/or data. The chip system may be formed by a chip, or may include a chip and other discrete devices.

In a tenth aspect, the present application provides a chip system, which includes a processor and is configured to implement the functions of the network device in the method of the foregoing aspects. In one possible design, the system-on-chip further includes a memory to store program instructions and/or data. The chip system may be formed by a chip, or may include a chip and other discrete devices.

In an eleventh aspect, the present application provides a computer-readable storage medium storing a computer program that, when executed, implements the method performed by a terminal device in the above-described aspects.

In a twelfth aspect, the present application provides a computer-readable storage medium storing a computer program which, when executed, implements the method performed by the network device in the above-described aspects.

Drawings

Fig. 1 is a schematic architecture diagram of a communication system suitable for use in the embodiments of the present application;

fig. 2A is a schematic diagram of a network architecture of a communication system according to an embodiment of the present application;

fig. 2B is a schematic diagram of another network architecture of a communication system according to an embodiment of the present application;

fig. 2C is a schematic diagram of another network architecture of a communication system according to an embodiment of the present application;

FIG. 3 is a schematic diagram of a CSI-RS based CSI measurement process;

fig. 4 is a schematic flowchart of CSI feedback provided in an embodiment of the present application;

fig. 5 is a schematic structural diagram of a communication device according to an embodiment of the present application;

fig. 6 is a schematic structural diagram of a communication device according to an embodiment of the present application;

fig. 7 is a schematic structural diagram of a communication device according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the embodiments of the present application will be described in further detail with reference to the accompanying drawings.

The technical solution provided in the embodiment of the present application may be applied to a fifth generation (5G) mobile communication system, such as a New Radio (NR) system, or a Long Term Evolution (LTE) system, or may also be applied to a next generation mobile communication system or other similar communication systems, which is not limited specifically.

Referring to fig. 1, an exemplary architecture diagram of a communication system applicable to the embodiment of the present application is shown, where the communication system may include a core network device, a network device, and at least one terminal. Fig. 1 illustrates an example in which at least one terminal is two terminals. The terminal is connected with the network equipment in a wireless mode, and the network equipment is connected with the core network equipment in a wireless or wired mode. The core network device and the network device may be independent different physical devices; or the function of the core network equipment and the logic function of the network equipment are integrated on the same physical equipment; or part of the functions of the core network device and part of the functions of the network device are integrated on the same physical device. It should be noted that fig. 1 is only an illustration, and the embodiment of the present application does not limit the number of core network devices, and terminals included in the mobile communication system. In some embodiments, the communication system may also include other network devices, such as wireless relay devices, wireless backhaul devices, and the like.

The technical scheme provided by the embodiment of the application can be used for wireless communication systems, such as 4.5G systems or 5G systems, further evolution systems based on LTE or NR, future wireless communication systems or other similar communication systems and the like.

Please refer to fig. 1, which illustrates a network architecture applied in the present embodiment. Included in fig. 1 are a network device and 6 terminal devices, which 6 terminal devices may be cellular phones, smart phones, laptops, handheld communication devices, handheld computing devices, satellite radios, global positioning systems, PDAs, and/or any other suitable device for communicating over a wireless communication system, and each may be connected to the network device. The six terminal devices are each capable of communicating with the network device. Of course, the number of terminal devices in fig. 1 is only an example, and may be fewer or more.

The network device is AN access device that the terminal device accesses to the mobile communication system in a wireless manner, and includes, for example, AN Access Network (AN) device, such as a base station (e.g., AN access point). Network equipment may also refer to equipment that communicates with the terminal over the air, such as other possible terminal devices. The network device may include an evolved Node B (NodeB or eNB or e-NodeB) in a Long Term Evolution (LTE) system or a long term evolution-advanced (LTE-a) system; or may also include next generation node B (gNB) in a 5G NR system; or may also include an access node in a wIreless fIdelity (Wi-Fi) system, etc.; or the Network device may be a relay station, a vehicle-mounted device, a Public Land Mobile Network (PLMN) device of future evolution, a device in a device-to-device (D2D) Network, a device in a machine-to-machine (M2M) Network, a device in an internet of things (IoT) Network, or a Network device in another PLMN Network, and the like. The embodiment of the present application does not limit the specific technology and the specific device form adopted by the wireless network device. For example, the network device in fig. 1 may be a base station, and the different systems correspond to different devices, for example, the network device in fig. 1 may correspond to an eNB in a fourth generation mobile communication technology (4G) system and correspond to a gNB in a 5G system.

A terminal device, which may be referred to as a terminal for short, also called a User Equipment (UE), is a device having a wireless transceiving function, and can transmit signals to a network device or receive signals from the network device. The terminal equipment is used for connecting people, objects, machines and the like, and can be widely used in various scenes, such as but not limited to the following scenes: cellular communication, device-to-device communication (D2D), vehicle-to-all (V2X), machine-to-machine/machine-type communication (M2M/MTC), internet of things (IoT), virtual Reality (VR), augmented Reality (AR), industrial control (industrial control), unmanned driving (self driving), remote medical (remote medical), smart grid (smart grid), smart furniture, smart office, smart wear, smart transportation, smart city (smart city), unmanned aerial vehicle, robot, etc. scenarios. The terminal equipment may sometimes be referred to as User Equipment (UE), a terminal, an access station, a UE station, a distant station, wireless communication equipment, or user equipment, among others. For example, the terminal device may be a mobile phone (mobile phone), a tablet computer (Pad), a computer with a wireless transceiving function, a Virtual Reality (VR) terminal, an Augmented Reality (AR) terminal, a wireless terminal in industrial control (industrial control), a wireless terminal in self driving (self driving), a smart speaker in an IoT network, a wireless terminal device in telemedicine, a wireless terminal device in a smart grid, a wireless terminal device in transportation security, a wireless terminal device in a smart city, or a wireless terminal device in a smart home, and the like. The terminal equipment may also be fixed or mobile. The embodiments of the present application do not limit this.

For example, the terminal device in the embodiments of the present application may be taken as an example and is not limited thereto, and in the embodiments of the present application, the terminal device may also be a wearable device. Wearable equipment can also be called wearable smart device or intelligent wearable equipment etc. is the general term of using wearable technique to carry out intelligent design, develop the equipment that can dress to daily wearing, like glasses, gloves, wrist-watch, dress and shoes etc.. While the various terminal devices described above, if located on (e.g. placed in or installed in) a vehicle, may be considered to be vehicle-mounted terminal devices, also referred to as on-board units (OBUs), for example.

In addition, in this embodiment, the terminal device may refer to a device for implementing a function of the terminal, or may be a device capable of supporting the terminal device to implement the function, such as a chip system, and the device may be installed in the terminal device. The terminal device can also be a vehicle detector, a sensor in a gas station, for example. Fig. 2A illustrates a communication network architecture in the communication system provided by the present application, and the embodiments shown in fig. 4 provided subsequently can be applied to the architecture. The first network device is a source network device (or called as an operating network device or a serving network device) of a terminal device (hereinafter, described by taking a UE as an example), and the second network device is a target network device (or called as a standby network device) of the UE, that is, a network device that provides a service for the UE after handover. It should be noted that in this application, "failure" may be understood as a failure of a network device and/or failure to provide service for one or more UEs for other reasons, which is simply referred to as failure. The "handover" in this application refers to handover of a network device serving a UE, and is not limited to "cell handover". For convenience of description, the network device is taken as a base station for example. The "handover" may refer to a handover due to a change in a base station serving the UE. For example, when a source base station of the UE fails, the UE is served by a backup base station. For another example, during the process of switching the UE from the source base station to communicate with another base station, the target base station after the switching provides service for the UE. The accessed cells before and after the UE is switched can be changed or not. It is to be understood that the standby network device is a relative concept, e.g., with respect to one UE, base station 2 is the standby network device of base station 1, and with respect to another UE, base station 1 is the standby network device of base station 2.

The first network device and the second network device may be two different devices, e.g., the first network device and the second network device are two different base stations. Optionally, the first network device and the second network device may also be two sets of function modules in the same device. The functional modules may be hardware modules, or software modules, or both hardware modules and software modules. For example, the first network device and the second network device are located in the same base station, and are two different functional modules in the base station. In one implementation, the first network device and the second network device are not transparent to the UE. The UE, when interacting with the respective network device, is able to know which network device it is interacting with at all. In another implementation, the first network device and the second network device are transparent to the UE. The UE is able to communicate with the network devices but does not know with which of the two network devices it is interacting. Alternatively, it may be that only one network device is considered for the UE. The first network device and the second network device are located in a dashed box, which indicates that the first network device and the second network device may not be transparent to the UE, or may be transparent. In the following description, the first network device, the second network device, and the terminal device (taking UE as an example) may be the first network device in the network architecture shown in fig. 2A, and the steps indicated by dashed lines in the drawings corresponding to the embodiments of the present application are optional steps, which are not described in detail in the following text.

Fig. 2B illustrates another communication network architecture in the communication system provided by the present application. As shown in fig. 2B, the communication system includes a Core Network (CN) and a Radio Access Network (RAN). Wherein the network equipment (e.g., base stations) in the RAN includes baseband devices and radio frequency devices. The baseband device may be implemented by one or more nodes, and the radio frequency device may be implemented independently as a remote device, integrated into the baseband device, or partially integrated into the baseband device. Network devices in a RAN may include Centralized Units (CUs) and Distributed Units (DUs), which may be centrally controlled by one CU. The CU and the DU may be divided according to the functions of the protocol layers of the radio network provided therein, for example, the functions of the PDCP layer and the above protocol layers are provided in the CU, and the functions of the protocol layers below the PDCP layer, for example, the functions of the RLC layer and the MAC layer, are provided in the DU. It should be noted that this division of the protocol layers is only an example, and may be divided in other protocol layers. The radio frequency device may be remote, not placed in the DU, or integrated in the DU, or partially remote and partially integrated in the DU, which is not limited in this application.

Fig. 2C illustrates another communication network architecture in the communication system provided by the present application. With respect to the architecture shown in fig. 2B, the Control Plane (CP) and the User Plane (UP) of a CU may also be separated and implemented as separate entities, respectively a control plane CU entity (CU-CP entity) and a user plane CU entity (CU-UP entity). In the network architecture, the signaling generated by the CU may be sent to the UE through the DU, or the signaling generated by the UE may be sent to the CU through the DU. The DU may pass through the UE or CU directly through protocol layer encapsulation without parsing the signaling. In the network architecture, the CUs may be divided into network devices on the RAN side and the CUs may be divided into network devices on the CN side, which is not limited in the present application.

An application scenario of the 5G communication system, international Telecommunication Union (ITU) defines three major application scenarios for 5G and future Mobile communication systems, which are Enhanced Mobile Broadband (eMBB), high reliability and Low Latency Communications (URLLC), and Massive Machine Type Communications (mtc), respectively. Among the typical eMBB services are: the services include ultra high definition video, augmented Reality (AR), virtual Reality (VR), and the like, and these services are mainly characterized by large transmission data volume and high transmission rate. Typical URLLC services are: the main characteristics of the applications of wireless control, motion control of unmanned vehicles and unmanned airplanes, and haptic interaction such as remote repair and remote operation in industrial manufacturing or production processes are that the services require ultra-high reliability, low time delay, less data transmission amount and are bursty. Typical mtc traffic is: industrial Wireless Sensor Network (IWSN) service, video surveillance (video surveillance) service, wearable (radios) service, etc., which are mainly characterized by huge number of networking devices, small amount of transmission data, and insensitivity of data to transmission delay, and these mtc terminals need to meet the requirements of low cost and very long standby time. No matter what kind of service is performed by the terminal device, when the network device sends data to the terminal device, the network device may schedule transmission of the data according to the CSI.

The following describes the relevant technical features of CSI measurement and CSI reporting from the terminal device to the network device.

The main idea of CSI measurement is to measure based on a Reference Signal (RS) with a known sequence, and calculate the final CSI according to the measurement result. For example, for the uplink channel, the measurement may be based on a Sounding Reference Signal (SRS). For the downlink channel, measurements may be made based on a channel state information-reference signal (CSI-RS). The embodiments of the present application are directed to measurement and feedback of CSI of a downlink channel, and therefore, the following mainly describes CSI measurement and feedback of a downlink channel.

Please refer to fig. 3, which is a flowchart of a method for measuring CSI of a downlink channel. As shown in fig. 3, the network device may send CSI-RS to the terminal device at time t 1. After receiving the CSI-RS, the terminal device measures the CSI-RS to calculate some index parameters of the CSI, such as Rank Indicator (RI), precoding Matrix Indicator (PMI), or Channel Quality Indicator (CQI). The terminal equipment can feed back one or more index parameters to the network equipment at the time t2 according to the CSI-RS configuration of the network equipment. Then, the network device may schedule downlink data according to CSI, e.g., CQI, fed back by the terminal device. For example, the network device schedules downlink data according to the CQI information fed back by the terminal device at time t 3.

As can be seen from fig. 3, the terminal device measures the channel at time t1, i.e. the CSI obtained by the terminal device describes the CSI of the channel at time t 1. However, the network device schedules downlink data to be CSI at time t3, that is, CSI at time t1 fed back by the terminal device is used by the network device at time t 3. Therefore, the network device performs data scheduling according to the CSI fed back by the terminal device, which results in a high probability of data transmission errors, that is, the high data reliability cannot be ensured, and the network device cannot be applied to an application scenario requiring high reliability, such as transmission of URLLC service. For example, when the terminal device measures a channel at time t1, the quality of the channel is better. However, when the channel is at the time t3, the channel quality changes, and if the network device still schedules downlink data according to the CSI fed back by the terminal device at the time t1, the probability of data transmission errors is high.

Another method for measuring CSI of a downlink channel is to measure CSI according to downlink data or PDSCH. That is, CSI is obtained from downlink data or PDSCH measurement (hereinafter, PDSCH measurement is taken as an example). For convenience of description, the CSI measurement in fig. 1 may be referred to as a first CSI measurement mode, and the CSI measurement mode according to downlink data or PDSCH measurement may be referred to as a second CSI measurement mode.

Both the first CSI measurement method and the second CSI measurement method relate to measurement configuration of the network device, and the terminal device feeds back CSI to the network device. The following respectively introduces the related network configuration and the content of CSI feedback by the terminal device with respect to the first CSI measurement mode and the second CSI measurement mode.

First, the relevant contents of the network configuration are described.

For the first CSI measurement manner, the CSI-RS configuration of the network device mainly includes two parts, one part is CSI-RS report configuration (ReportConfig) (abbreviated as CSI-ReportConfig), and the other part is CSI-RS resource configuration (ResourceConfig) (abbreviated as CSI-ResourceConfig). The ResourceConfig is used for configuring relevant information of a time-frequency resource (referred to as a CSI-RS resource herein) corresponding to a reference signal of a measurement channel. The CSI-RS resources may be divided into two types from a functional point of view. These two types are respectively: non-zero power CSI-RS (NZP-CSI-RS) and zero power CSI-RS (ZP-CSI-RS). The ZP-CSI-RS refers to a zero power CSI-RS, and the essential meaning of the ZP-CSI-RS is that the target base station does not send any information on the configured ZP-CSI-RS, and the user performs detection on the resource, and the detected signal is interference (because the target base station does not send any information). The NZP-CSI-RS and the ZP-CSI-RS are different in that, for the NZP-CSI-RS, the target base station sends a known sequence on the configured resource, and a channel/interference can be obtained through the known sequence. Since the ZP-CSI-RS is generally used for measuring Interference, the ZP-CSI-RS can also be referred to as Channel State Information Interference Measurement (CSI-IM).

The CSI-report configuration is mainly used for configuring information related to CSI reporting, for example, the types of the configurable CSI reporting are divided into three types, where the three types of reporting are periodic CSI (P-CSI), semi-persistent CSI (SP-CSI), and aperiodic CSI (a-CSI). Examples of the channel state measurement index include RI, PMI, and CQI). In view of the configuration of the CSI-RS resource, the CSI-RS resource also includes three types, which are a periodic resource, a semi-persistent resource, and an aperiodic resource. As shown in table 1, there is a certain relationship between the reporting type of the channel state and the configuration manner of the CSI-RS resource corresponding thereto. As can be seen from table 1, for the periodic CSI-RS resource, P-CSI reporting, SP-CSI reporting, and a-CSI reporting are supported. For aperiodic resources, only reporting of A-CSI is supported.

TABLE 1

CSI-RS resource	P-CSI	SP-CSI	A-CSI
				Periodicity of the cycle	Support for	Support for	Support for
Semi-persistent property	Do not support	Support for	Support for
				Non-periodic	Do not support	Do not support	Support for

The following describes configurations related to CSI-RS measurement, for example, a CSI Resource configuration (CSI-ResourceConfig), a CSI reporting configuration (CSI-ReportConfig), a configuration of a NZP-CSI-RS Resource set (NZP-CSI-RS-ResourceSet), a configuration of a CSI-IM Resource set (CSI-IM-ResourceSet), a configuration of a NZP-CSI-RS Resource (NZP-CSI-RS-Resource), a configuration of a CSI-IM Resource (CSI-IM-Resource), and the like. The network device configures the CSI-RS resource, that is, configures the CSI-RS resource through configuration information (i.e., CSI-ResourceConfig). Similarly, the network device configures the NZP-CSI-RS resource set by the configuration information (i.e., NZP-CSI-RS-ResourceSet). The network device configures the set of CSI-IM resources with configuration information (i.e., CSI-IM-ResourceSet). The network equipment configuration information (i.e., NZP-CSI-RS-Resource) configures the NZP-CSI-RS resources. The network device configures the CSI-IM resources through configuration information (i.e., CSI-IM-Resource).

a) The NZP-CSI-RS-ResourceSet, the set of CSI-RS resources used to configure the NZP, may include at least one resource. The terminal device may measure the CSI according to the resources and feed back the CSI obtained by the measurement. When multiple resources exist in one resource set, the terminal device specifically feeds back CSI measured on which resource, which is indicated by a CRI variable fed back by the terminal device, for example, CRI =0, indicating that the CSI fed back by the terminal device is CSI measured on a resource with resource id =0.

The NZP-CSI-RS-ResourceSet may configure a parameter NZP-CSI-ResourceSetId, i.e., an Identity (ID) of a CSI-RS resource set of the NZP, to identify the CSI-RS resource set of the NZP. The NZP-CSI-RS-Resources set may also configure parameters NZP-CSI-RS-Resources to configure the Resources comprised by the CSI-RS resource set of the NZP. The NZP-CSI-RS-Resources may be associated to each NZP-CSI-RS resource by NZP-CSI-RS-resource id.

b) CSI-IM-ResourceSet, configuring a set of resources for measuring interference. The CSI-IM-ResourceSet is similar to the NZP-CSI-RS-ResourceSet and will not be described here.

c) The NZP-CSI-RS-Resource is used for configuring information related to the NZP-CSI-RS Resource. The NZP-CSI-RS-Resource can be related to the Resource set through NZP-CSI-RS-Resource id.

d) And the CSI-IM-Resource is used for configuring relevant information of the CSI-IM Resource. And the CSI-IM-Resource is related to the CSI-IM Resource set through the CSI-IM-Resource id.

e) And the CSI-ResourceConfig is used for configuring information related to the CSI-RS resource. For example, the following parameters may be configured: parameter reportConfigId, parameter csi-RS-ResourceSetList, parameter resourcettype. Wherein the reportconfigId is used to mark the Identity (ID) of the CSI-ResourceConfig, which can be associated to the CSI-ReportConfig. CSI-RS-ResourceSetList, i.e. configuration information for configuring a CSI-RS resource set queue, a queue for configuring a resource set, where the configured queue may include a resource set for channel measurement and may also include a resource set for interference measurement. The CSI-RS-ResourceSetList is associated to the configuration of the set of resources by NZP-CSI-RS-resourcesetlid and/or CSI-IM-resourcesetlid. The resourceType is used to configure the type of CSI-RS resource, such as a periodic (periodic) resource, a semi-persistent (semi-persistent) resource, and an aperiodic (aperiodic) resource.

f) And the CSI-report config is mainly used for configuring information related to CSI reporting. For example, some of the following information may be configured: parameter reportConfigId, parameter esourcesForChannelMeasurement, parameter CSI-IM-resourceference, parameter nzp-CSI-RS-resourceference, parameter reportConfigType, and parameter reportQuantity. Wherein, the reportConfigId is the ID number of the CSI-ReportConfig and is used for marking the CSI-ReportConfig. The resource ForChannelMeasurement is used for configuring the resource of the CSI-RS for channel measurement, and can be related to the resource configuration through the CSI-ResourceConfigId. The CSI-IM-ResourceForInterference is used for configuring the CSI-RS resource for interference measurement, and can be related to the resource configuration through the CSI-ResourceConfigId. The NZP-CSI-RS-resource ForInterference is used for configuring NZP-CSI-RS resources for interference measurement, and can be related to resource configuration through CSI-ResourceConfigId. The reportQuantity is used to configure the reported amount, for example, the reportQuantity may indicate one or more information of CRI, RI, PMI, CQI, etc. by different configurations. The reportConfigType is used to configure the type of CSI reporting, such as periodic CSI (P-CSI), semi-persistent CSI (SP-CSI), or aperiodic CSI (a-CSI).

The following describes the relevant technical features of reporting CSI by a terminal device.

The CSI reported by the terminal device to the network device may be a CQI. The terminal device may quantize the measured channel state information, for example, quantize the CQI, as shown in table 2, which is a CQI index table. When the terminal device feeds back the CQI to the network device, the terminal device may feed back a CQI index to the network device, that is, feed back one CQI index as in table 2, so as to inform the network device of the modulation scheme and the code rate determined by the terminal device. For example, the terminal device informs the network device that the CQI index is 3, and the terminal device may determine, according to table 2 and index value 3, that the modulation scheme to be used is QPSK and the code rate is 78/1024. It should be noted that there are multiple CQI index tables supported by the prior art, and as to which table the terminal device feeds back the CQI, the network device may additionally indicate the CQI index table. In table 2, one code rate column (code rate x 1024) indicates the code rate multiplied by 1024. Taking CQI index =3 as an example, the code rate is 78/1024=0.0762.

TABLE 2

It is assumed that the terminal device has obtained the current channel state from the CSI-RS measurements. The terminal device assumes that there is a downlink data packet transmitted on the CSI reference resource, and selects a maximum CQI index, so that the BLER of the downlink data packet during transmission on the current channel (in the measured channel state) is smaller than the Target BLER. For example, the terminal device quantizes the measured channel state information into a certain row in table 2, and feeds back the channel state information to the network device. However, since MCS and CQI depend on SINR, transport Block Size (TBS) and Target BLER, different quantization values will be obtained even for the same channel state information, different Target BLER, and different downlink packet size during quantization. For example, the signal to interference plus noise ratio (SINR) measured by the terminal device through the CSI-RS is 10dB, the target BLER is 0.00001, and if the size of the downlink data packet assumed by the terminal device is 1000 bits, the CQI index quantized by the terminal device may be 10; assuming that the size of the downlink data packet is 100 bits, the CQI index quantized by the terminal device may be 5. However, if the terminal device and the network device understand differently about the size of the downlink data packet, erroneous channel state information feedback will result. For example, when the terminal device quantizes the channel state information, it is assumed that the size of the data packet is 1000 bits, but when the network device recovers the channel state through the channel state information fed back by the terminal device, if it is assumed that the size of the data packet is 100 bits, the network device may obtain channel state information different from that fed back by the terminal device. The CSI reference resource is used to ensure that the terminal device and the network device have the same understanding of the size of the downlink data packet. The network device and the terminal device can determine the size of the downlink data packet corresponding to the CSI reference resource, and therefore, transmission of wrong channel state information due to different understandings of the network device and the terminal device on the size of the downlink data packet is avoided.

The network device may indicate the size of the target BLER that the terminal device employs in calculating the CQI. As an alternative, the network device may indicate the size of the target BLER by a CQI index table. For example, the CQI index table may be associated with a target BLER. For example, the target BLER for CQI index Table 1 is 10 ^-1 The target BLER corresponding to CQI index Table 2 is also 10 ^-1 The target BLER corresponding to CQI index Table 3 is 10 ^-5 . If the network equipment indicates the terminal equipment and the CQI index table is the CQI index table 3, the target BLER adopted when the terminal equipment calculates the CQI is 10 ^-5 (ii) a If the CQI index table is indicated to be the CQI index table 1 or the CQI index table 2, the target BLER adopted when the terminal equipment calculates the CQI is 10 ^-1 。

Optionally, the indication information of the target BLER used by the network device to instruct the terminal device to calculate the CQI is carried in the CSI-RS reporting configuration.

The reporting of the CSI also supports wideband feedback and subband feedback. The wideband feedback means that only one value is fed back in the whole reporting bandwidth. The subband feedback indicates that feedback is separately provided for each subband (subband). For a fixed-size bandwidth part (BWP), the number of Physical Resource Blocks (PRBs) included in each subband is fixed. I.e., the size of each sub-band is specified, as shown in table 3. For example, if a BWP has a size of 50 PRBs, or a BWP contains 50 PRBs, the subband size is 4 or 8. The specific subband size may be configured by higher layer signaling.

TABLE 3

For subband feedback, feedback may also be performed on a discrete plurality of subbands or a continuous plurality of subbands. The narrowband CQI feedback is divided into two parts, the first part is wideband CQI, that is, one wideband CQI is calculated on all configured subbands, and the wideband CQI is fed back. The second part is the CQI for each sub. The subband offset value level (subband offset level) fed back by the terminal device for the subband indicates the offset value of the corresponding subband CQI relative to the wideband CQI, so as to save feedback overhead. For example, the terminal device feeds back the sub-band offset level, and the sub-band offset level = sub-band CQI index-wideband CQI index. Wherein, the sub-band CQI index is the index of the sub-band CQI, and the wideband CQI index is the index of the wideband CQI. For example, the wideband CQI in the prior art is quantized with 4 bits, as shown in table 2 above.

The terminal device feeds back an offset value (also referred to herein as delta-CQI) with respect to the wideband CQI for the subbands. It should be understood that delta-CQI is an offset value relative to a reference value, rather than an absolute value. Currently, the feedback of the terminal device for the narrowband CQI uses table 4. For example, wideband CQI index =5. If the terminal device calculates a CQI offset value (offset level) =0, then after the network device receives the terminal device's feedback, it can be determined from table 4 that the sub-band CQI is also 5. Also for example, if the offset level =1 calculated by the terminal device, the network device may determine the index of the sub-band CQI to be 6 according to table 4. For example, if the offset level =3 (i.e., corresponding to row 3 of table 4) calculated by the terminal device, the network device cannot accurately restore the index value of the sub-band CQI, and only the index value of the sub-band CQI is equal to or greater than 7. It should be understood that if the offset level calculated by the terminal device is less than or equal to-1, the network device cannot accurately recover the sub-band CQI value, and only can obtain a value with an index value of the sub-band CQI being less than or equal to 4.

TABLE 4

Sub-band differential CQI value	Offset level
		0	0
1	1
		2	≥2
3	≤-1

The CSI fed back by the terminal device to the network device may also be a Modulation and Coding Scheme (MCS). Like CQI, MCS may also be quantized, for example, please see table 5, which is an MCS index table. Each row in table 5 corresponds to a set of modulation order and code rate. Different modulation orders correspond to different modulation modes. For example, the modulation order Qm =2 corresponds to a QPSK modulation scheme, qm =4 corresponds to 1694am, qm =6 corresponds to 64QAM. There may be cases of Qm =8 and/or Qm =10 in other tables, it being understood that Qm =8 corresponds to 256qam and Qm =10 corresponds to 1024QAM. Generally, the modulation scheme and the code rate are determined by an MCS index (index), and the terminal device feeds back the MCS index to the network device to inform the network device of the modulation scheme and the code rate determined by the terminal device. That is, the network device may also select a row in table 5 through the indication information, so as to notify the terminal device of the modulation scheme and the code rate used for transmitting data. For example, the network device informs the terminal device that the MCS index is 3, and the terminal device may determine that the modulation order Qm =2 and the code rate is 64/1024 according to table 5. Namely, the modulation mode adopted by the terminal equipment is QPSK, and the code rate is 64/1024.

Table 5 is only an illustration. There are currently 3 MSC index tables to support different applications. Each MSC index table corresponds to different reliability requirements, and which table is specifically selected can be configured to the terminal device by high-level configuration parameters. It should be understood that there may be more MCS tables in the communication evolution process, or 3 MCS tables in the existing protocol may be modified, and the application does not limit the number and specific content of the MCSs.

TABLE 5

Comparing the MCS index table and the CQI index table, it can be found that each row in the MCS index table and the CQI index table indicates a modulation mode, a code rate, and a spectral efficiency. That is, the nature of the MCS index table and the CQI index table is the same. The currently defined MCS index tables are 3, and the network device may additionally instruct the terminal device to select which MCS index table to report the MCS. Similarly, there are 3 CQI index tables, and the network device may additionally instruct the terminal device to select which CQI index table to report the CQI. The CQI index table has 16 rows, the MCS index table has 32 rows, and one MCS index table corresponds to one CQI index table. For the mutually corresponding CQI index table and MCS index table, each row in the CQI index table is obtained from every other row in the MCS index table.

It should be appreciated that similar to subband feedback, in order to save more overhead, when the terminal device feeds back the MCS, an offset value (also referred to herein as delta-MCS) of the MCS may also be fed back. Similarly, when the terminal device feeds back the CQI, an offset value (also referred to as delta-CQI herein) of the CQI may also be fed back. That is, the terminal device feeds back an offset (offset) with respect to a certain reference value. In the following description, the terminal device feeds back MCS as an example. For example, if the measured MCS index of the terminal device is 10 and the reference value is 5, the MCS index fed back by the terminal device may be 5 or-5. For example, if delta MCS is defined as the difference between the MCS index (real MCS) measured by the terminal device and the reference value (reference MCS), the MCS index fed back by the terminal device is 5; if delta MCS is defined as the difference between reference MCS and reference MCS, then the MCS index fed back by the terminal equipment is-5.

It should be understood that reference MCS exists to save overhead. If the reference MCS is chosen properly, the channel state information measured by the terminal device may fluctuate within a small range around the reference MCS, for example, so that more accurate channel state information may be fed back with fewer bits. For example, if the reference MCS is 10, the channel state information measured by the terminal device is, for example, 9,10,11 or 12, i.e., fluctuates around 10. In this case, the terminal device may only need 2-bit information to feed back more accurate channel state information, but if the reference MCS selection is not appropriate, the effect of saving overhead may not be achieved. For example, if the reference MCS is 0, the channel state information measured by the terminal device is, for example, 9,10,11 or 12, in which case the terminal device feeds back to the third row in table 4. Therefore, the network device cannot obtain an accurate CQI. Table 4 may be extended, i.e. table 4 is increased from 4 rows to more rows, in order to obtain an accurate CQI, but this is equivalent to increasing the bit information, and there is no way to save overhead. Alternatively, the spacing between offset values may be increased. For example, table 4 is modified to table 6, but this may result in an increased MCS or CQI quantization error. The above example is followed, i.e. reference MCS is 10 and channel state information is 9,10,11,12. The terminal device feeds back the CQI by using table 6, and10, 11, and 12 are quantized to the first row of table 6, so that the network device still cannot accurately distinguish the CQI fed back by the terminal device. I.e. channel state information that may result in large errors due to inappropriate reference MCS selection.

TABLE 6

Sub-band differential CQI value	Offset level
		0	3
1	6
		2	≥9
3	≤-2

In view of this, the embodiment of the present application provides a CSI feedback method, and a method for feeding back CSI based on a determined reference MCS improves accuracy of feeding back CSI while saving feedback overhead.

The scheme provided by the embodiment of the application is described in detail below with reference to the relevant drawings. In the following description, the terminal device measures PDSCH to obtain CSI is taken as an example, and the terminal device feeds back MCS or CQI. The CSI measured based on the PDSCH may indicate one row in the MCS index table or one row in the CQI index table. In the context of the present specification,

meaning that the rounding is done down,

meaning rounded up, e.g., when x is greater than or equal to 1 and less than 2, then

x is greater than 1 and less than or equal to 2, then

It should be understood that in the following description, the terminal device obtains CSI according to PDSCH is taken as an example, but the method of the present invention is not limited to CSI obtained only based on PDSCH, for example, CSI may also be obtained through CSI-RS.

Referring to fig. 4, a flow of a method for sending and receiving a common signal according to an embodiment of the present application is shown. In the following description, the method is applied to the network architecture shown in fig. 1 as an example. In addition, the method may be performed by two communication apparatuses, for example, a first communication apparatus and a second communication apparatus, where the first communication apparatus may be a network device or a communication apparatus capable of supporting the network device to implement the functions required by the method, or the first communication apparatus may be a terminal device or a communication apparatus capable of supporting the terminal device to implement the functions required by the method, and may of course be other communication apparatuses such as a system on chip. The same applies to the second communication apparatus, which may be a network device or a communication apparatus capable of supporting the network device to implement the functions required by the method, or the second communication apparatus may be a terminal device or a communication apparatus capable of supporting the terminal device to implement the functions required by the method, or of course, other communication apparatuses, such as a chip system, may also be used. The implementation manners of the first communication device and the second communication device are not limited, for example, the first communication device may be a network device, the second communication device is a terminal device, or both the first communication device and the second communication device are network devices, or both the first communication device and the second communication device are terminal devices, or the first communication device is a network device, and the second communication device is a communication device capable of supporting the terminal device to implement the functions required by the method, and so on. The network device is, for example, a base station.

For convenience of introduction, in the following, the method is performed by a network device and a terminal device as an example, that is, the first communication apparatus is a network device and the second communication apparatus is a terminal device as an example. If the present embodiment is applied to the network architecture shown in fig. 1, the network device described below may be a network device in the network architecture shown in fig. 1, and the terminal device described below may be any terminal device in fig. 1.

S401, the terminal device determines the first CSI.

With regard to specific ways of determining the first CSI by the terminal device, several examples are given below: in the first way, the terminal device measures the received PDSCH to obtain CSI of the PDSCH, i.e. first CSI. The specific method for determining the first CSI is not limited in the embodiment of the present application, for example, the terminal device may obtain the first CSI according to a demodulation reference signal (DMRS) corresponding to the PDSCH, or obtain the first CSI according to data carried in the PDSCH. Optionally, the first CSI is determined according to a TBS (transport block size) corresponding to the PDSCH. Optionally, the TBS used for calculating the first CSI is equal to the TBS corresponding to the PDSCH. Alternatively, the terminal device may also determine the first CSI based on CSI-RSs from the network device. Alternatively, the terminal device may also jointly determine the first CSI based on the CSI-RS and the PDSCH.

Optionally, the first CSI may indicate one or more of a modulation scheme, a coding rate, and a spectral efficiency. The first CSI may be indicated based on the MCS index table. For example, the first CSI may indicate an index value of the MCS, and one or more of a modulation scheme, a coding rate, and a spectral efficiency may be determined from the MCS index table according to the index value. Or the first CSI indicates a row in the MCS index table, and then determines one or more of a modulation scheme, a coding rate, and a spectral efficiency. Or the first CSI may also be indicated based on the CQI index table. For example, the first CSI may indicate an index value of the CQI, and one or more of a modulation scheme, a coding rate, and a spectral efficiency may be determined from a CQI index table according to the index value. Or, the first CSI indicates a row in the CQI index table, and then determines one or more of a modulation scheme, a coding rate, and a spectral efficiency. Optionally, the network device may indicate, to the terminal device, an index table used for calculating the first CSI. For example, the network device sends first indication information to the terminal device, where the first indication information may indicate an index table used for calculating the first CSI, and the index table may be a CQI index table or an MCS index table. Take CQI index table as an example. The network device may configure three index tables, e.g., CQI index table 1, CQI index table 2, CQI index table 3, respectively. The first indication information may indicate a CQI index table 1, and the terminal device determines one or more of the modulation scheme, the coding rate, and the spectral efficiency according to the CQI index table 1.

In a second way, in this embodiment, the terminal device may determine the first CSI according to a Target BLER indicated by the network device. For example, the network device may send DCI to the terminal device, where the DCI may instruct the terminal device to calculate a Target BLER to be used by the MCS corresponding to the PDSCH. It should be understood that DCI dynamic indication is more flexible. The DCI indicatesThe Target BLER may be 10 ^-1 、10 ^-2 、10 ^-3 、10 ^-4 、10 ^-5 、10 ^-6 、10 ^-7 Or 10 ^-8 And so on. That is, the network device may indicate other than 10 via DCI ^-1 Or 10 ^-5 May also be 10 ^-2 、10 ^-3 、10 ^-4 、10 ^-6 、10 ^-7 Or 10 ^-8 And the like. The method and the device do not limit the value of Target BLER dynamically indicated by DCI. Optionally, the terminal device determines the Target BLER from the BLER candidate value set according to the indication information of the network device. The Target BLER is used to determine the first CSI. Optionally, the set of BLER candidate values is network device configured, or protocol predetermined. Optionally, the BLER candidate set includes at least 10 ^-1 And10 ^-5 And one value other than the above.

As an alternative, the indication information (for example, referred to as second indication information) of the Target BLER is configured in the configuration information related to the CSI reporting configuration. For example, the second indication information is arranged in the aforementioned CSI-ReportConfig. It should be noted that, in the embodiment of the present application, a specific name of "configuration information related to CSI reporting configuration" is not limited, and here, it is taken as an example that the configuration information used for CSI reporting configuration is CSI-ReportConfig. In some embodiments, a new field may be added to the CSI-ReportConfig or an existing field may be multiplexed to carry the second indication information. Alternatively, the second indication information may be associated by CSI-ReportConfig, for example by CSI-ReportConfigId. Different second indication information may be configured in different CSI-ReportConfig. The network equipment may trigger CSI reporting according to the DCI, and then calculate a Target BLER used by the first CSI, that is, a Target BLER associated with the triggered CSI reporting. The DCI may be a DCI for scheduling one uplink data transmission, a DCI for scheduling a downlink data transmission, or a DCI for a PDSCH corresponding to the first CSI. The network device can flexibly trigger different CSI-Report through the DCI, so that the indication of the first reference value Y is more flexible, and the terminal device can feed back the first CSI more accurately while reducing the overhead.

As another example, the Target BLER may be indicated by higher layer signaling. It should be appreciated that higher layer signaling indicates that signaling overhead can be saved. The Target BLER indicated by the higher layer signaling may be 10-1, 10-2, 10-3, 10-4, 10-5, 10-6, 10-7, or 10-8, etc. That is, the network device may indicate, through the higher layer signaling, that other values, such as 10-2, 10-3, 10-4, 10-6, 10-7, or 10-8, may be available in addition to 10-1 or 10-5. The value of the Target BLER indicated by the high-level signaling is not limited. Optionally, the terminal device determines the Target BLER from the BLER candidate value set according to the indication information of the network device. The Target BLER is used to determine the first CSI. Optionally, the set of BLER candidate values is configured by the network device or predetermined by the protocol. Optionally, the set of BLER candidate values comprises at least one value other than 10-1 and 10-5. It is understood that higher layer signaling refers to signaling issued by a higher layer protocol layer. The higher layer protocol layer may be considered to be at least one protocol layer above the physical layer. For example, the higher layer protocol layers may include at least one of the following protocol layers: a Medium Access Control (MAC) layer, a Radio Link Control (RLC) layer, a Packet Data Convergence Protocol (PDCP) layer, a Radio Resource Control (RRC) layer, and a non-access stratum (NAS) layer.

In the embodiment of the present application, the network device may indicate the Target BLER through the first indication information, or may indicate the Target BLER through the second indication information. The second indication information may be independent indication information from the first indication information. Therefore, the terminal equipment can determine the Target BLER according to the first indication information and also can determine the Target BLER according to the second indication information, and the method is more flexible.

For example, the first indication information may be used to indicate a CQI index table, through which the Target BLER is indicated. For example, a plurality of CQI index tables may be preconfigured, each CQI index table may be associated with one Target BLER, different CQI index tables may be associated with the same Target BLER, and different Target BLERs may also be associated. For example, the Target BLER corresponding to CQI index table 1 is 10 ^-1 The Target BLER corresponding to the CQI index Table 2 is also 10 ^-1 The Target BLER corresponding to the CQI index Table 3 is 10 ^-5 . The network device indicates a CQI index table through the first indication information, that is, indicates a Target BLER corresponding to the CQI index table. If the CQI index table indicated by the first indication information is the CQI index table 3, the Target BLER adopted when the terminal equipment calculates the first CSI is 10 ^-5 . If the CQI index table indicated by the first indication information is the CQI index table 1 or the CQI index table 2, the Target BLER adopted when the terminal equipment calculates the first CSI is 10 ^-1 . As another example, the Target BLER corresponding to CQI index Table 1 is 10 ^-1 The Target BLER corresponding to the CQI index Table 2 is also 10 ^-3 The Target BLER corresponding to the CQI index Table 3 is 10 ^-5 . If the CQI index table indicated by the first indication information is the CQI index table 2, the Target BLER adopted when the first CSI is calculated is 10 ^-3 (ii) a If the first indication information indicates that the CQI index table is the CQI index table 3, the Target BLER adopted when the terminal equipment calculates the CQI is 10 ^-5 . And determining one or more of the modulation mode, the coding rate and the spectral efficiency indicated by the first CSI by a CQI index table or an MCS index table configured for the terminal equipment by the network equipment. For example, if the network device configures CQI index table 1 or MCS index table 1 to the terminal device, the first CSI is used to indicate an index of the CQI index table 1 or MCS index table 1, and determine one or more of a modulation scheme, a coding rate, and a spectral efficiency from the CQI index table 1 or MCS index table 1 through the index. Or, a row in the CQI index table 1 or the MCS index table 1 is determined through the first CSI, and then one or more items of the modulation scheme, the coding rate, and the spectral efficiency are determined. The terminal device may determine one or more of the modulation scheme, the coding rate, and the spectral efficiency according to the first CSI and a CQI index table or an MCS index table configured by the network device.

For example, the first indication information may be used to indicate an MCS index table, through which the Target BLER is indicated. Similar to the first indication information indicating Target BLER through the MCS index table. Multiple MCS index tables may also be preconfigured, each MCS index table may be associated with one Target BLER, different MCS index tables may be associated with the same Target BLER, or different Target BLERs may be associated. Specifically, the Target BLER may be indicated by the MCS index table with reference to the first indication information, which is not described herein again.

It should be noted that, if the network device sends the first indication information and the second indication information to the terminal device, the terminal device may determine the Target BLER according to the second indication information, instead of using the first BLER determined by the first indication information. For example, the first indication information indicates a first BLER, and the second indication information indicates a second BLER. And the terminal equipment receives the first indication information and the second indication information, and the terminal equipment can determine that the Target BLER is the second BLER. It should be understood that, if the terminal device receives the first indication information and does not receive the second indication information, the terminal device determines the Target BLER according to the first indication information, that is, the Target BLER is the first BLER. And if the terminal equipment receives the second indication information and does not receive the first indication information, the terminal equipment determines the Target BLER according to the second indication information, namely the Target BLER is the second BLER.

Because the Target BLER to be adopted by the terminal equipment for calculating the MCS corresponding to the PDSCH is indicated by the network equipment, the Target BLER adopted by the terminal equipment and the network equipment when determining the MCS corresponding to the PDSCH is the same, and the problem that the MCS determined by the terminal equipment and the network equipment has larger deviation due to different Target BLERs adopted by the terminal equipment and the network equipment when determining the MCS corresponding to the PDSCH can be avoided. For example, the problem that the MSC corresponding to the PDSCH serves as the reference MCS, which causes a large error in the channel state information, that is, a large deviation exists in the MCS determined by the terminal device and the network device, can be avoided. For example, on the network device side, the network device can set SINR1=10db, target bler =10 ^-3 Selecting a MCS corresponding to the PDSCH, for example, MCS1; on the terminal equipment side, it is still assumed that the channel state at this time is SINR2=10dB, but when the terminal equipment obtains MCS from PDSCH measurement, the Target BLER selected is 10 ^-5 The MCS determined by the terminal device is, for example, MCS2. Obviously, MCS1 and MCS2 are different and have a bias. It should be understood that MCS1 and MCS2 do not match, which would result in a larger MCS index quantization error. It should be noted that, here, only the Target BLER is taken as an example, and a large deviation exists between the MCS determined by the terminal device and the MCS determined by the network device. It should be understood that MCS or CQI is related to SINR, TBS, and Target BLER. Similar to the Target BLER, the difference in SINR and/or TBS selected by the network device and the terminal device may also result in a larger deviation in MCS determined by the terminal device and the network device.

S402, the terminal device sends first information to the network device, and correspondingly, the network device receives the first information, where the first information is used to indicate an offset value, and the offset value is used to indicate a difference value between a first reference value and the first CSI, or the offset value is used to indicate a difference value between the first CSI and the first reference value.

After the terminal equipment obtains the first CSI, the obtained first CSI is fed back to the network equipment. In order to save feedback overhead, in the embodiment of the present application, the terminal device feeds back to the network device an offset value (offset level) of CSI, that is, an offset value of CSI obtained by the terminal device with respect to a reference value (for example, referred to as a first reference value). For example, the terminal device may determine an offset value of the first CSI with respect to the first reference value, i.e., a difference between the first CSI and the first reference value, or a difference between the first reference value and the first CSI. The terminal device feeds back the first CSI to the network device, and may send first information to the network device, where the first information includes the offset value. As mentioned above, if the first reference value is not properly selected, overhead cannot be saved or CSI error is large. Therefore, the embodiments of the present application provide various ways for determining the first reference value, so that the accuracy of CSI is guaranteed as much as possible while feedback overhead is saved. In the embodiments of the present application, specific names of the reference values are not limited. For example, the first reference value serves as a reference for the terminal device to feed back CSI, so in some embodiments, the first reference value may also be referred to as a first reference value.

In some embodiments, the first information may further include a first PMI or a first RI. The first PMI corresponds to the first CSI, for example, the first CSI is obtained according to the first PMI. For example, the value indicated by the first CSI is one row in the CQI index table, and at this time, the terminal device determines a CQI index according to the precoding matrix indicated by the first PMI. Similarly, the first RI corresponds to the first CSI, e.g., the first CSI is obtained according to the first RI. For example, the value indicated by the first CSI is a row in the CQI index table, and at this time, the terminal device determines the CQI index according to the rank indicated by the first RI. In still other embodiments, the first information may further include a first reference value.

Taking the first CSI as an index value indicating MCS as an example, it should be understood that the first CSI corresponds to CQI similarly. In the embodiment of the present application, the first CSI may indicate the MCS index value X, and may also indicate a value related to the MCS index value X, for example, X1, that is, the offset value Z is related to either X or X1. In addition, the offset value Z is related to either the first reference value Y or Y1, where Y1 is a value related to the first reference value Y. That is, the terminal device may determine the offset value from X1 and Y1, may determine the offset value from X and Y, and may determine the offset value from X1 and Y.

Illustratively, the offset value Z is related to X and Y, then there may be: z = X-Y, or Z = Y-X; alternatively, the first and second electrodes may be,

alternatively, the first and second electrodes may be,

alternatively, the first and second electrodes may be,

alternatively, the first and second electrodes may be,

alternatively, Z =2 (X-Y); alternatively, Z =2 (Y-X).

Illustratively, offset value Z is associated with X1 and Y, then there may be: z = X1-Y; alternatively, Z = Y-X1; alternatively, the first and second electrodes may be,

alternatively, the first and second electrodes may be,

alternatively, the first and second electrodes may be,

alternatively, the first and second electrodes may be,

alternatively, Z =2 (X1-Y); alternatively, Z =2 (Y-X1).

Illustratively, offset value Z is associated with X and Y1, then there may be: z = X-Y1; alternatively, Z = Y1-X; alternatively, the first and second liquid crystal display panels may be,

alternatively, the first and second electrodes may be,

alternatively, the first and second electrodes may be,

alternatively, the first and second electrodes may be,

alternatively, Z =2 (X-Y1); alternatively, Z =2 (Y1-X).

Illustratively, the offset value Z is related to X1 and Y1, then there may be an offset value Z that satisfies any of the following relationships:

z = X1-Y1; alternatively, Z = Y1-X1; alternatively, the first and second electrodes may be,

alternatively, the first and second electrodes may be,

alternatively, the first and second electrodes may be,

alternatively, the first and second liquid crystal display panels may be,

alternatively, Z =2 (X1-Y1); alternatively, Z =2 (Y1-X1).

Wherein X1 is determined by X, and X1 and X can satisfy any relationship as follows:

alternatively, the first and second electrodes may be,

alternatively, X1=2X. I.e. the first CSI is either X or X1.

Wherein Y1 is determined by Y, and Y1 and Y can satisfy any relationship as follows: alternatively, the first and second electrodes may be,

alternatively, the first and second liquid crystal display panels may be,

alternatively, Y1=2Y.

It should be noted that, when Y1= Y, Y1 and Y correspond to MCS or CQI; when in use

Alternatively, the first and second electrodes may be,

y1 corresponds to CQI, and Y corresponds to MCS; when Y1=2y, Y1 corresponds to MCS and Y corresponds to CQI. This ensures that the CQI index table and the MCS index table correspond to each other, and each row in the CQI index table is obtained from every other row in the MCS index table.

In addition, each row in the CQI index table is acquired from every other row in the MCS index table due to the CQI index table and the MCS index table corresponding to each other. Therefore, if X, Y, and Z correspond to the same index table, then no rounding or 2-fold operation is required between X1 and X, no rounding or 2-fold operation is required between Y1 and Y, and no rounding or 2-fold operation is required between Z and X1-Y1 or Y1-X1. If X, Y and Z correspond to the same index table, a rounding operation or a 2-fold operation may be required between X1 and X, a rounding operation or a 2-fold operation may be required between Y1 and Y, and a rounding operation or a 2-fold operation may be required between Z and X1-Y1 or Y1-X1. For example, X and Y correspond to MCS index table and Z corresponds to CQI index table, then rounding operation is required between X1 and X, and rounding operation is also required between Y1 and Y. If X and Y correspond to CQI index tables and Z corresponds to MCS index tables, 2-time operation is needed between X1 and X and 2-time operation is needed between Y1 and Y, so that a more accurate offset value can be obtained, and more accurate CSI can be fed back.

In the embodiment of the present application, the first reference value is either Y or Y1. Of course, Y1 can be determined by determining Y, and therefore, the manner of determining the first reference value Y will be described below by taking the first reference value Y as an example.

In the embodiment of the present application, the first reference value Y may be directly determined or may be indirectly determined. The following describes possible ways of determining the first reference value Y provided in the embodiment of the present application, including but not limited to the following ways.

In the first mode, the network device indicates the first reference value Y to the terminal device. The network device may directly indicate the first reference value Y to the terminal device, or may indirectly indicate the first reference value Y. Indirectly indicating the first reference value Y, it can be considered that the network device indicates a parameter related to the first reference value Y, for example a second reference value Y', from which the terminal device can determine the first reference value Y. The way in which the network device directly indicates the first reference value Y and the possible implementation ways in which the first reference value Y is indirectly indicated are described below, respectively.

In the direct indication mode, the network device sends second information to the terminal device, where the second information is used to indicate the first reference value Y. The terminal device receives the second information, and can determine the offset value directly according to the first reference value Y indicated by the second information. The embodiment of the present application does not limit a specific implementation manner of the second information.

For example, the second information is configured in configuration information related to CSI reporting configuration, for example, the second information is configured in the CSI-report configuration. It should be noted that, in the embodiment of the present application, a specific name of "configuration information related to CSI reporting configuration" is not limited, and herein, the configuration information used for CSI reporting configuration is CSI-ReportConfig, for example. In some embodiments, a new field may be added to the CSI-ReportConfig or an existing field may be multiplexed to carry the second information. Alternatively, the second information may be associated by CSI-ReportConfig, for example by CSI-ReportConfigId. Different second information may be configured in different CSI-ReportConfig. The network device may indicate different first reference values Y to the terminal device according to specific requirements, and trigger the CSI-Report based on the DCI, thereby implementing selection of different first reference values Y. The DCI may be a DCI scheduling uplink data transmission, a DCI scheduling downlink data transmission, or a DCI of a PDSCH corresponding to the first CSI. The network device can flexibly trigger different CSI-Report through the DCI, so that the indication of the first reference value Y is more flexible, and the terminal device can feed back the first CSI more accurately while reducing the overhead.

Illustratively, the second information may be carried by DCI. For example, there are a plurality of possible reference values to which the first reference value Y belongs. It can also be considered that there is a candidate value set of the first reference value Y. The second information is used to select one reference value from the candidate value set as the first reference value Y. The number of bits occupied by the second information may be determined according to the number of reference values in the candidate set. For example, please refer to table 7, which is a table of the correspondence between the first reference value Y and the second information. Table 7 takes 4 candidate values of the first reference value as an example, and the second information occupies 2 bits.

TABLE 7

Second information	Y
		00	1
01	2
		10	4
11	10

As shown in table 7, the second information indicates a value of "01", i.e., indicates that the first reference value Y is 2. The candidate values and the corresponding relationship shown in table 7 are only exemplary, the first reference value that can be indicated by the second information may also be other values, and the corresponding relationship table between the first reference value Y and the second information may also be in other forms.

It should be noted that the candidate value set of the first reference value Y may be predefined by a protocol, and may also be configured by a network device, or the candidate value set of the first reference value Y may be agreed by the network device and a terminal device. If the network device configures a candidate value set of the first reference value Y, the candidate value set may be configured by reporting configuration information configured by CSI, for example, the candidate value set may be configured in CSI-ReportConfig as described above; or, the candidate value set may be associated with configuration information configured by CSI reporting, for example, the CSI-ReportConfig; alternatively, the set of candidate values may be associated by a parameter for association to a CSI-ReportConfig, such as CSI-ReportConfigId. Different sets of candidates may be configured at different CSI-reportconfigs, or different sets of candidates may be associated with different CSI-reportconfigs. The network device can indicate the configuration of the candidate value set more flexibly by triggering different CSI-reportconfigs, so that the indication of the first reference value Y is more flexible, and the terminal device can adopt the more accurate first reference value Y when feeding back the first CSI.

The indirect indication method includes, but is not limited to, the following methods.

In a first indirect indication manner, the network device sends second information to the terminal device, where the second information is used to indicate a first candidate value set, and the first candidate value set includes a first reference value Y. The terminal device receives the second information, and determines the first reference value Y according to the first candidate value set indicated by the second information. In a possible implementation manner, a relationship between a first reference value Y in the first candidate value set and a Target BLER used for calculating the first CSI may be predefined or configured by the network device, so that the terminal device determines the first reference value Y according to the first candidate value set and the Target BLER used for calculating the first CSI.

For example, the second information is carried through DCI. Please refer to table 8, which is a table of correspondence between the first candidate value set and the second information. In table 8, taking 4 first candidate value sets as an example, the second information occupies 2 bits.

TABLE 8

Second information	Y, corresponding to Target BLER =10 ^-1	Y, corresponding to Target BLER =10 ^-5
			00	1	4
01	2	10
			10	4	11
11	10	12

As shown in table 8, the second information indicates a value of "10", i.e., the first candidate value set includes "4 and 11". The terminal equipment receives the second information, and if the terminal equipment calculates the Target BLER =10 adopted by the first CSI ^-1 If yes, determining the first reference value Y to be 2; if the terminal equipment calculates the Target BLER =10 adopted by the first CSI ^-5 Then the first reference value Y is determined to be 10. Optionally, the second information is configured in configuration information related to CSI reporting configuration, which is specifically described above and is not described again.

In a second indirect indication manner, the network device sends second information to the terminal device, where the second information is used to indicate the second reference value Y'. And the terminal equipment receives the second information and determines the first reference value Y according to the second reference value Y' indicated by the second information. In this indication manner, the second information may also be configured in configuration information related to CSI reporting configuration, for example, in the CSI-report configuration, specifically refer to related contents in the foregoing direct indication manner, which is not described herein again.

Of course, the second information may also be carried through DCI. For example, there is a candidate set of the second reference value Y ', and the second information is used to select one reference value from the candidate set as the second reference value Y'. The number of bits occupied by the second information may be determined according to the number of reference values in the candidate set. For example, please refer to table 9, which is a table of the correspondence between the second reference value Y' and the second information. Table 9 takes 4 candidate values of the second reference value Y' as an example, and the second information occupies 2 bits.

TABLE 9

Second information	Y’
		00	1
01	2
		10	4
11	10

As shown in table 8, the second information indicates a value of "01", i.e., indicates that the second reference value Y' is 2. It should be noted that the candidate value set of the second reference value Y 'may be predefined, or may be configured by the network device, or the candidate value set of the second reference value Y' may be agreed between the network device and the terminal device. If the network device configures the candidate value set of the second reference value Y', the candidate value set may be configured by the configuration information configured by CSI reporting, for example, the candidate value set may be configured in the CSI-ReportConfig as described above; or, the candidate value set may be associated with configuration information configured by CSI reporting, for example, the CSI-ReportConfig; alternatively, the set of candidate values may be associated by a parameter for association to a CSI-ReportConfig, such as a CSI-ReportConfigId. Different sets of candidate values may be configured at different CSI-reportconfigs, or different CSI-reportconfigs may be associated with different sets of candidate values. The network device may trigger the CSI-ReportConfig through the DCI, so as to indicate the configuration of the candidate value set more flexibly, and thus, indicate the second reference value Y' more flexibly.

In a third indirect indication manner, the network device sends second information to the terminal device, where the second information is used to indicate the second candidate value set. The second set of candidate values comprises a second reference value Y'. And the terminal equipment receives the second information, determines a second reference value Y 'according to the second candidate value set indicated by the second information, and determines the first reference value Y according to the second reference value Y'. In a possible implementation manner, a relationship between the second reference value Y 'in the second candidate value set and the Target BLER used for calculating the first CSI may be predefined or configured by the network device, so that the terminal device determines the second reference value Y' according to the second candidate value set and the Target BLER used for calculating the first CSI.

For example, the second information is carried through DCI. Please refer to table 10, which is a table of correspondence between the second candidate value set and the second information. In table 10, for example, there are 4 second candidate value sets, and the second information occupies 2 bits.

Watch 10

As shown in table 10, the value indicated by the second information is "01", i.e., the second candidate value set includes "2 and 10". The terminal equipment receives the second information, and if the terminal equipment calculates the Target BLER =10 adopted by the first CSI ^-1 If yes, determining the second reference value Y' as 2; if the terminal equipment calculates the Target BLER =10 adopted by the first CSI ^-5 Then the second reference value Y' is determined to be 10. Optionally, the second information is configured in configuration information related to CSI reporting configuration, which is specifically described above and is not described again.

In this embodiment, the second information may also be used to indicate an MCS corresponding to a PDSCH, where the PDSCH corresponds to the first CSI. In this way, the correspondence relationship of the MCS index value and the second reference value Y' may be predefined or configured. The terminal device receives the second information, and may determine the second reference value Y ' according to a corresponding relationship between the MCS index value and the second reference value Y ', thereby determining the first reference value Y according to the second reference value Y '.

In some embodiments, one second reference value Y' may correspond to one MCS index value in one MCS index table. That is, Y' is configured to a certain row in the MCS index table, i.e. a column is added on the basis of the MCS index table. When a certain MCS index is indicated by the second information, Y' is also determined. For example, please refer to table 11, which shows a corresponding relationship between the second reference value Y' and the MCS index value.

TABLE 11

Table 11 shows that the network device may also indicate the MCS corresponding to the PDSCH and the second reference value Y ', for example, the second indication information is used to indicate the MCS corresponding to the PDCSH and the second reference value Y', so that signaling overhead may be saved. In some embodiments, the network device may indicate the MCS and the second reference value Y' corresponding to the PDSCH, respectively, that are carried by different signaling.

It should be noted that, in some embodiments, a candidate value set of the second reference value Y 'may also be configured for the index value of one MCS, and the candidate value set includes the second reference value Y'. That is, one or more columns Y' are added to Table 11. The network device indicates the MCS corresponding to the PDSCH, the terminal device may determine a candidate value set according to the MSC corresponding to the PDSCH indicated by the network device, and then determine a final second reference value Y' according to a correspondence between the candidate value set and the Target BLER used for calculating the first CSI.

In a possible implementation, one second reference value Y' may also correspond to one MCS index table. For example, there are 3 MCS index tables, which are MCS index table 1, MCS index table 2, and MCS index table 3. The MCS index table 1, the MCS index table 2, and the MCS index table 3 correspond to a second reference value Y', respectively. For example, MCS index table 1 corresponds to Y ' =1, MCS index table 2 corresponds to Y ' =5, and MCS index table 3 corresponds to Y ' =6. In this case, the second information may indicate an MCS index table, i.e., the second reference value Y'. For example, the second information indicates the MCS index table 2, and may indirectly indicate that the second reference value Y' is 5. Of course, in some embodiments, multiple Y' may also be configured for one MCS index table, which is specifically referred to the foregoing third indirect indication manner and is not described herein again.

Similar to the network device indicating the MCS corresponding to the PDSCH and indicating the second reference value Y', the network device may also indicate the MCS corresponding to the PDSCH and indicate the first reference value Y. In a possible implementation, the correspondence of the MCS index value to the first reference value Y may be predefined or configured. The terminal device receives the second information, and can determine the first reference value Y according to the corresponding relationship between the MCS index value and the first reference value Y. Of course, the network device may indicate the MCS corresponding to the PDSCH and the first reference value Y separately, that is, the MCS corresponding to the PDSCH and the first reference value Y are carried through different signaling. The network device may also indicate the MCS corresponding to the PDSCH and the first reference value Y at the same time, for example, the second indication information is used to indicate the MCS corresponding to the PDCSH and the first reference value Y, so that signaling overhead may be saved.

The second indirect indication manner and the third indirect indication manner describe the network device indicating the second reference value Y'. As an alternative implementation, the terminal device may determine the second reference value Y' according to the second CSI related to the first CSI.

In the embodiment of the present application, the second CSI is related to the first CSI by that the second CSI satisfies at least one of the following 6 items:

1) And the second CSI is the CSI closest to the first CSI in time before the reporting time of the first CSI. Optionally, the first CSI reporting time may be the first symbol or the last symbol of a time-frequency resource where the first CSI is reported. The first CSI reporting time may also be a starting position of a first symbol of a time-frequency resource where the first CSI is reported, or an ending position of a last symbol.

2) The second CSI is a CSI closest to the PDSCH in time before the PDSCH corresponding to the first CSI. The PDSCH corresponding to the first CSI means that the first CSI is measured according to the PDSCH. Optionally, before the PDSCH, the time is before the first symbol of the time-frequency resource corresponding to the PDSCH, or before the last symbol of the time-frequency resource corresponding to the PDSCH, or before the start time of the first symbol of the time-frequency resource corresponding to the PDSCH, or before the end time of the last symbol of the time-frequency resource corresponding to the PDSCH.

3) The target BLER associated with the second CSI is the same as the target BLER employed by the first CSI.

4) The ReportConfigId of the second CSI is associated with the ReportConfigId of the first CSI. Optionally, the association relationship may be indicated by the network device. For example, the ReportConfigId corresponding to the first CSI is 2, the network device indicates that the ReportConfigId associated with the ReportConfigId of the first CSI is 3, and the second CSI is CSI corresponding to the ReportConfigId of 3.

5) The CSI-ResourceConfigId of the second CSI is associated with the CSI-ResourceConfigId of the first CSI. Optionally, the association relationship may be indicated by the network device. For example, the CSI-ResourceConfigId corresponding to the first CSI is 2, the network device indicates that the CSI-ResourceConfigId associated with the CSI-ResourceConfigId of the first CSI is 3, and the second CSI is a CSI measurement resource corresponding to the CSI-ResourceConfigId of 3. That is, the second CSI is CSI measured according to the CSI measurement resource corresponding to CSI-ResourceConfigId of 3.

6) The nzp-CSI-ResourceSetId of the second CSI is associated with the nzp-CSI-ResourceSetId of the first CSI. Optionally, the association relationship may be indicated by the network device. For example, if the nzp-CSI-ResourceSetId corresponding to the first CSI is 2, the network device indicates that the nzp-CSI-ResourceSetId associated with the nzp-CSI-ResourceSetId of the first CSI is 3, and the second CSI is a CSI measurement resource corresponding to the nzp-CSI-ResourceSetId of 3. That is to say, the second CSI is CSI measured by the CSI measurement resource corresponding to the nzp-CSI-ResourceSetId of 3.

The second CSI satisfies any one of items 1) to 6) above, and may also satisfy a plurality of items 1) to 6) at the same time. For example, the target BLER associated with the second CSI is the same as the target BLER used by the first CSI, and the second CSI is closest to the first CSI in time before the reporting time of the first CSI. For example, the first CSI employs a target BLER of 10 ^-1 Then the second CSI should satisfy that the target BLER for the second CSI is also 10 ^-1 And the time domain position of the second CSI satisfies: before the first CSI reporting time, the first CSI reporting time is closest to the first CSI in timeCSI。

Similarly, the target BLER associated with the second CSI is the same as the target BLER used by the first CSI, and is closest to the PDSCH in time before the PDSCH corresponding to the first CSI. Or the ReportConfigId of the second CSI is associated with the ReportConfigId of the first CSI, and is closest to the first CSI in time before the reporting time of the first CSI. Or the ReportConfigId of the second CSI is associated with the ReportConfigId of the first CSI and is closest to the PDSCH in time before the PDSCH corresponding to the first CSI. Or the CSI-ResourceConfigId of the second CSI is associated with the CSI-ResourceConfigId of the first CSI, and is closest to the first CSI in time before the reporting time of the first CSI. Or the CSI-ResourceConfigId of the second CSI and the CSI-ResourceConfigId of the first CSI are associated and are closest to the PDSCH in time before the PDSCH corresponding to the first CSI. Or the nzp-CSI-ResourceSetId of the second CSI is associated with the nzp-CSI-ResourceSetId of the first CSI, and is closest to the first CSI in time before the reporting time of the first CSI. Or the nzp-CSI-ResourceSetId of the second CSI is associated with the nzp-CSI-ResourceSetId of the first CSI and is closest to the PDSCH in time before the PDSCH corresponding to the first CSI.

It is noted that, herein, the second CSI may be P-CSI.

It should be understood that the first CSI is related to SINR, TBS, and Target BLER. In order to ensure that the first CSI fluctuates around the first reference value Y obtained by the second CSI measurement as much as possible, that is, the difference between the first CSI and the first reference value Y obtained by the second CSI measurement is small. In the embodiment of the application, the time domain resource size of the CSI reference resource corresponding to the first CSI is one time unit. The time unit may be one slot, or one OFDM symbol, or a plurality of OFDM symbols, or a plurality of slots. For example, the TBS for the second CSI and the TBS for the first CSI are the same to align time domain resources of CSI reference resources for the second CSI and the first CSI. Or the precoding matrix corresponding to the first CSI and the second CSI are the same. Or the precoding matrix corresponding to the first CSI is determined according to the second CSI. Or the rank corresponding to the second CSI and the rank corresponding to the first CSI are the same. Therefore, the first reference value Y obtained through the second CSI can be ensured to be more accurate as much as possible. It should be noted that the TBS corresponding to the second CSI refers to the TBS used for calculating the second CSI. Similarly, the precoding matrix corresponding to the first CSI refers to a precoding matrix adopted for calculating the first CSI. The rank corresponding to the second CSI refers to a rank adopted when the second CSI is calculated.

The terminal device may determine the wideband CQI corresponding to the second CSI as a second reference value Y'. Or, the terminal device may determine the second reference value Y' according to the sub-band CQI corresponding to the second CSI and at least one sub-band CQI corresponding to the PDSCH corresponding to the first CSI. That is, the second reference value Y' is determined based on CQIs calculated from the second CSI and several narrowband CQIs corresponding to the PDSCH. For example, the sub-bands corresponding to the second CSI are sub-band 1, sub-band 2, \8230, and the sub-bands corresponding to sub-band 10, pdsch are sub-band 1 and sub-band 5, and then the second reference value Y' is determined according to the sub-band CQI of the second CQI on sub-band 1 and sub-band 10.

After the terminal device determines the second reference value Y ', the first reference value Y is determined according to the second reference value Y', which includes, but is not limited to, the following determination manners.

In the first determination mode, the terminal device may directly determine the first reference value Y according to the second reference value Y'. Illustratively, Y' and Y satisfy any of the following relationships: y = Y',

alternatively, Y =2Y'.

In the second determination mode, the terminal device may determine the first reference value Y according to the second reference value Y' and other related information. The other related information may be information related to an MCS corresponding to the PDSCH, or may be information related to the first CSI, for example, the second CSI related to the first CSI. In the present embodiment, the first reference value Y is related to either the second reference value Y 'or Y1', wherein Y1 'is related to the second reference value Y'. And/or the first reference value Y is related to a or to a ', wherein a' is related to the second reference value a. That is, the terminal device may determine Y from Y ' and a, or determine Y from Y ' and a ', or determine Y from Y1' and a '. Optionally, a may be determined by an MCS corresponding to the PDSCH, or may be determined by the second CQI. Optionally, the value of a may be an index value of an MCS corresponding to the PDSCH, or the value of a may also be an index value corresponding to the second CQI. Wherein the MCS corresponding to the PDSCH indicates the MCS adopted for transmitting the PDSCH.

Illustratively, Y is related to a and Y', then there may be: y = a + Y ', Y = a-Y', Y = -a + Y ', or Y = -a-Y'.

Illustratively, Y is related to a and Y1', then there may be: y = a + Y1', Y = a-Y1', Y = -a + Y1', or Y = -a-Y1'.

Illustratively, Y is related to a 'and Y', then there may be: y = a '+ Y', Y = a '-Y', Y = -a '+ Y', or Y = -a '-Y'.

Illustratively, Y is related to a 'and Y1', then Y, Y1 'and a' may satisfy any of the following relationships:

y = a '+ Y1', Y = a '-Y1', Y = -a '+ Y1', or Y = -a '-Y1'. Wherein Y1 'and Y' satisfy any one of the following relationships:

or Y1'=2Y'.

a' and a satisfy any one of the following relationships:

a' =2a. That is, the terminal device may determine Y from a and Y1, may determine Y from a and Y1', may determine Y from a' and Y1, and may determine Y from a 'and Y1'.

In a second manner, the terminal device may determine the second CSI and determine the first reference value Y based on the second CSI.

The terminal device may determine the wideband CQI corresponding to the second CSI as the first reference value Y. Or, the terminal device may determine the first reference value Y according to the sub-band CQI corresponding to the second CSI and at least one sub-band CQI corresponding to the PDSCH corresponding to the first CSI. That is, the first reference value Y is determined based on CQIs calculated for several narrowband CQIs corresponding to the second CSI and the PDSCH. For example, the sub-bands corresponding to the second CSI are sub-band 1, sub-band 2, \8230, and the sub-bands corresponding to sub-band 10, pdsch are sub-band 1 and sub-band 5, and then the first reference value Y is determined according to the sub-band CQI of the second CQI on sub-band 1 and sub-band 10.

After the terminal device determines the second reference value Y ', the specific implementation manner of determining the first reference value Y according to the second reference value Y' may refer to the foregoing related contents, which is not described herein again.

In a third way, the first CSI is determined by the terminal device according to the retransmitted PDSCH (referred to as the first PDSCH). In this case, the first reference value may be determined according to the first PDSCH.

It is understood that the data block TB (transport block) carried in the PDSCH is retransmitted for another transmission of the TB block carried in its corresponding original PDSCH. For example, the first transmission corresponding to the first PDSCH is the second PDSCH. The TB carried in the first PDSCH is another transmission of the TB carried in the second PDSCH. That is, the retransmission is to transmit the same TB again. The TBs corresponding to the initial transmission and the retransmission are the same TBs. Multiple retransmissions, first retransmission and second retransmission, \ 8230;, may be performed corresponding to the primary TB. The TB of each retransmission bearer is the same. It should be understood that the time-frequency resources and MCSs corresponding to the initial transmission and the transmission may be the same or different.

Optionally, the indication information of the MCS corresponding to the first PDSCH indicates that the PDSCH is a retransmitted PDSCH.

Optionally, the indication information of the MCS corresponding to the first PDSCH indicates an invalid state. For example, MCS index 29,30, or 31 shown in table 5 is indicated.

For the retransmitted PDSCH, the indication information of the associated MCS may indicate a modulation scheme/modulation order, but not a code rate and/or Spectral Efficiency (SE). At this time, the code rate used by the TB carried in the retransmitted PDSCH is calculated according to the size of the primary TB and the time-frequency resources of the retransmitted PDSCH.

In one implementation, the first reference value may be determined according to a spectral efficiency corresponding to the first PDSCH, for example, including several optional schemes.

As an alternative, the first reference value Y is an index corresponding to the minimum spectral efficiency difference value in the target MCS index table/CQI index table. For example, the target MCS index table or CQI index table is the MCS index table shown in table 5. If the calculated SE =0.06, Y =0.

As another optional scheme, the first reference value Y is an index in the target MCS index table or CQI index table, where the difference between the target MCS index table and the spectral efficiency SE is the smallest and is greater than an index corresponding to SE. The target MCS index table or CQI index table is used as the MCS index table shown in table 5. If the calculated SE =0.06, Y =1.

As another optional scheme, the first reference value Y is an index in the target MCS index table or CQI index table, which has the smallest difference from the spectral efficiency SE and is smaller than the index corresponding to SE. The target MCS index table or CQI index table is used as the MCS index table shown in table 5. If the calculated SE =0.06, Y =0.

Optionally, the spectral efficiency corresponding to the first PDSCH may be determined according to the first TBS and/or the first time-frequency resource. Wherein, the first TBS is a size of a TB carried by the first PDSCH. The first time-frequency resource is a time-frequency resource occupied by the first PDSCH, or the first time-frequency resource is a time-frequency resource occupied by downlink data in the first PDSCH. For example, TBS corresponding to the first PDSCH is S1, and Resource Element (RE) occupied by the first PDSCH is S2. The spectral efficiency Z = S1/S2 can be obtained. S2 may be a time-frequency resource occupied by the first PDSCH, or a time-frequency resource used for carrying downlink data in the first PDSCH. For example, the total time-frequency resources occupied by the first PDSCH are 100 REs. Where there are 80 REs for carrying downlink data, then Y may be 100 or 80. Specifically determined according to different schemes.

In a possible implementation manner, the first reference value is determined according to a modulation mode, TBS, and/or a size of a time-frequency resource corresponding to the first PDSCH. For example, the target MCS index table or CQI index table is the MCS index table shown in table 5. The MCS indication information corresponding to the first PDSCH indicates that the MCS index is 29, and the modulation scheme corresponding to the first PDSCH is QPSK. Then the modulation scheme indicated by the MCS index corresponding to the first reference value can be obtained as QPSK. Further, the spectral efficiency may be determined by combining the spectral efficiency determination method, which is not described in detail herein. For example, the first reference value is an index indicating that the modulation scheme is QPSK and the difference between the spectral efficiency and the spectral efficiency corresponding to the first PDSCH is the smallest in table 5.

In a fourth mode, the first CSI is determined by the terminal device according to the retransmitted PDSCH (referred to as the first PDSCH). In this case, the terminal device may determine the first reference value for the second PDSCH. The second PDSCH is the originally transmitted PDSCH corresponding to the first PDSCH.

In one possible implementation, the first reference value is determined according to an MCS employed by the second PDSCH. For example, the first reference value is the MCS used by the second PDSCH or an index of the MCS. For another example, the first reference value is Y = I1+ I2, or Y = I1-I2, and Y = I2-I1. Wherein, I1 is the MCS used by the second PDSCH or an index of the MCS, and I2 is indicated by the network device, or I2 is related to the retransmission times. For example, I2 is 1 when the first PDSCH is the first retransmission of the second PDSCH, and I2 is 2 when the first PDSCH is the second retransmission of the second PDSCH.

It should be noted that, if the first CSI is obtained according to the first PDSCH and the terminal device does not receive the second PDSCH, the first information sent by the terminal device may indicate the first state, or the offset value may indicate the first state. The first state is used to indicate that the terminal device cannot obtain the first CSI, or that the terminal device does not receive the second PDSCH, or out of range.

It should be understood that if the first CSI is a CQI, that is, the first CSI is a row selected from a CQI index table, a value range of the first reference value Y is related to a valid value of the CQI. I.e. the maximum value of the first reference value Y should not exceed the effective value of CQI. The effective value of the CQI refers to a measured CQI. If the first CSI is an MCS, that is, the first CSI is a row selected from the MCS index table, the maximum value of the first reference value Y should not exceed the valid value of the MCS. The valid value of MCS refers to the measured MCS. For example, if the first CSI is CQI, the maximum value of the first reference value Y may be 15, that is, the first reference value Y is greater than 0 and less than 15; and/or the first reference value Y is greater than or equal to 0; and/or less than or equal to 15. If the first CSI is MCS, the maximum value of the first reference value Y may be 28, i.e. the first reference value Y is greater than 0 and less than 28; and/or the first reference value Y is greater than or equal to 0; and/or less than or equal to 28.

Therefore, no matter the terminal equipment selects the CQI index table for feedback or selects the MCS index table for feedback, the value fed back by the terminal equipment finally does not exceed the value range of the first reference value Y. For example, if the first reference value Y is-5, the MCS index value X measured by the terminal device is in the range of 0 to 28, or the CQI index value X measured by the terminal device is in the range of 0 to 15. Since X is greater than Y, the respective index values of MCS feedback can be better or CQI feedback can be better.

After the terminal device determines the first reference value Y, it may determine an offset value according to the obtained first CSI and feed back the offset value to the network device. For example, the terminal device feeds back an index of the offset value to the network device. For example, please refer to tables 12 and 13, which are tables of the corresponding relationship between the index of the offset value and the offset value, respectively. Note that the values of Offset levels in tables 12 and 13 are merely exemplary, the correspondence between the index of the Offset value and the Offset value is also merely exemplary, and the correspondence between the index of the Offset value and the Offset value may be in other forms. For another example, the terminal device may indicate the offset value through the first information, see table 14, table 15, or table 16. The candidate value of the offset value may also be a part of table 14, table 15 or table 16, or a combination of at least two table values in table 14, table 15 and table 16.

TABLE 12

Indexing of Offset level	Offset level
		0	0
1	1
		2	≥2
3	≤-1

Watch 13

Indexing of Offset level	Offset level
		0	0
1	-1
		2	≥1
3	≤-2

TABLE 14

Watch 15

First information	Offset level
		00	0
01	2
		10	≥4
11	≤-2

TABLE 16

First information	Offset level
		00	0
01	-1
		10	≥1
11	≤-2

Since the terminal device feeds back the offset value, the number of occupied bits is less than that of the terminal device which directly feeds back the first CSI, and thus feedback overhead is saved. In addition, as the network device and the terminal device understand the first reference value Y consistently, the first CSI determined by the network device is the first CSI fed back by the terminal device, that is, the accuracy of the CSI fed back by the terminal device can be ensured.

In the embodiments provided in the present application, the method provided in the embodiments of the present application is introduced from the perspective of interaction between the terminal device and the network device. The steps executed by the network device may also be implemented by different communication apparatuses. For example: the first device is configured to generate second information, and the second device is configured to send the second information, that is, the first device and the second device jointly complete the steps performed by the network device in the embodiment of the present application. When the network architecture includes one or more Distributed Units (DUs), one or more Centralized Units (CUs) and one or more Radio Units (RUs), the steps performed by the network device may be implemented by the DUs, CUs and RUs, respectively. In order to implement the functions in the method provided by the embodiments of the present application, the terminal device and the network device may include a hardware structure and/or a software module, and the functions are implemented in the form of a hardware structure, a software module, or a hardware structure plus a software module. Whether any of the above-described functions is implemented as a hardware structure, a software module, or a hardware structure plus a software module depends upon the particular application and design constraints imposed on the technical solution.

The embodiment of the present application provides a communication apparatus based on the same inventive concept as the method embodiment. The following describes a communication device for implementing the above method in the embodiment of the present application with reference to the drawings.

Fig. 5 is a schematic block diagram of a communication device 500 according to an embodiment of the present application. The communication apparatus 500 may be the network device in fig. 1, and is configured to implement the method for the network device in the foregoing method embodiment. The specific functions can be seen from the description of the above method embodiments.

The communication device 500 includes one or more processors 501. The processor 501 may also be referred to as a processing unit and may perform certain control functions. The processor 501 may be a general purpose processor or a special purpose processor, etc. For example, it includes: a baseband processor, a central processing unit, an applications processor, a modem processor, a graphics processor, an image signal processor, a digital signal processor, a video codec processor, a controller, a memory, and/or a neural network processor, among others. The baseband processor may be used to process communication protocols as well as communication data. The central processor may be used to control the communication device 500, execute software programs and/or process data. The different processors may be separate devices or may be integrated in one or more processors, e.g., on one or more application specific integrated circuits.

Optionally, one or more memories 502 are included in the communication device 500 to store instructions 504 that are executable on the processor to cause the communication device 500 to perform the methods described in the above method embodiments. Optionally, the memory 502 may further store data therein. The processor and the memory may be provided separately or may be integrated together.

Optionally, the communication device 500 may include instructions 503 (which may also be sometimes referred to as code or program), and the instructions 503 may be executed on the processor, so that the communication device 500 performs the method described in the above embodiments. Data may be stored in the processor 501.

Optionally, the communication device 500 may further include a transceiver 505 and an antenna 506. The transceiver 505 may be referred to as a transceiver unit, a transceiver circuit, a transceiver, an input/output interface, etc. for implementing the transceiving function of the communication device 500 through the antenna 506.

Optionally, the communication device 500 may further include one or more of the following components: the wireless communication module, the audio module, the external memory interface, the internal memory, the Universal Serial Bus (USB) interface, the power management module, the antenna, the speaker, the microphone, the input/output module, the sensor module, the motor, the camera, or the display screen, etc. It is understood that in some embodiments, the communications apparatus 500 may include more or fewer components, or some components integrated, or some components separated. These components may be hardware, software, or a combination of software and hardware implementations.

The processor 501 and the transceiver 505 described herein may be implemented on an Integrated Circuit (IC), an analog IC, a radio frequency integrated circuit (RFID), a mixed signal IC, an Application Specific Integrated Circuit (ASIC), a Printed Circuit Board (PCB), an electronic device, or the like. The communication apparatus described herein may be implemented as a standalone device (e.g., a standalone integrated circuit, a cell phone, etc.), or may be part of a larger device (e.g., a module that may be embedded within other devices).

In some possible embodiments, the communication apparatus 500 can correspondingly implement the behavior and the function of the terminal device in the foregoing method embodiment, for example, implement the method executed by the terminal device in the embodiment of fig. 4. For example, the communication apparatus 500 may be a terminal device, a component (e.g., a chip or a circuit) applied in the terminal device, or a chip set in the terminal device or a part of the chip for performing the related method function. The transceiver 505 may be used to perform all of the receiving or transmitting operations performed by the terminal device in the embodiment shown in fig. 4, e.g., S401, S403 in the embodiment shown in fig. 4, and/or other processes for supporting the techniques described herein. Wherein the processor 501 is configured to perform all operations performed by the terminal device in the embodiment shown in fig. 4 except transceiving operations, such as S402 in the embodiment shown in fig. 4, and/or other processes for supporting the techniques described herein.

In some embodiments, processor 501 is configured to determine the first CSI; the transceiver 505 is configured to transmit first information to a network device, the first information indicating an offset value. Wherein the offset value is used to indicate a difference between the first reference value and the first CSI; alternatively, the offset value is used to indicate a difference between the first CSI and the first reference value.

In one possible implementation, the transceiver 505 is further configured to: second information is received from the network device, the second information being used to determine the first reference value.

In one possible implementation, the second information indicates a first reference value; or, the second information indicates a second reference value, which can be used to determine the first reference value; or, the second information indicates a first candidate value set including a second reference value used for determining the first reference value; alternatively, the second information indicates a second set of candidate values, which includes the first reference value.

In one possible implementation, the processor 501 is further configured to: determining second CSI for determining the first reference value, the second CSI being related to the first CSI.

In one possible implementation, the second CSI satisfies at least one of:

In one possible implementation, the determining the first reference value using the second CSI includes:

the second CSI corresponds to a wideband CQI, which is used to determine the first reference value; or the second CSI corresponds to a wideband CQI, which is a second reference value Y used for determining the first reference value Y; or the sub-band CQI corresponding to the second CSI and the at least one sub-band CQI corresponding to the PDSCH corresponding to the first CSI are used to determine the first reference value.

In a possible implementation, the transceiver 502 is further configured to receive first indication information and/or second indication information, the first indication information being used for indicating the first BLER, and the second indication information being used for indicating the second BLER. Processor 501 is further configured to determine a target BLER based on the first indication information and/or the second indication information, where the target BLER is a first BLER or a second BLER; and determining a first CSI according to the target BLER.

In a possible implementation, the processor 501 is specifically configured to:

receiving first indication information, not receiving second indication information, and determining the target BLER as a first BLER; or, receiving second indication information, not receiving the first indication information, and determining that the target BLER is a second BLER; or receiving the first indication information and the second indication information, and determining that the target BLER is a second BLER.

In a possible implementation, the second indication information is DCI.

In a possible implementation manner, the communication apparatus 500 does not receive the first PDSCH corresponding to the first PDSCH, and the first information is used to indicate the first state, or the offset value is used to indicate the first state, where the first state is used to indicate that the communication apparatus 500 cannot obtain the first CSI.

In one possible implementation, the processor 501 is specifically configured to: determining the first CSI based on a target BLER, wherein the target BLER is indicated by a DCI.

In some possible embodiments, the communication apparatus 500 can correspondingly implement the behaviors and functions of the network device in the foregoing method embodiment, for example, implement the method performed by the network device in the embodiment of fig. 4. For example, the communication apparatus 500 may be a network device, a component (e.g., a chip or a circuit) applied in the network device, or a chip set in the network device or a part of the chip for performing the related method function. The transceiver 505 may be used to perform all of the receiving or transmitting operations performed by the network device in the embodiment shown in fig. 4, e.g., S401, S403 in the embodiment shown in fig. 4, and/or other processes for supporting the techniques described herein. Processor 501 is configured to perform all operations performed by a network device in the embodiment shown in fig. 4, except transceiving operations, and/or other processes to support the techniques described herein.

In some embodiments, the transceiver 505 is configured to receive first information indicating an offset value indicating a difference between a first reference value and first CSI;

processor 501 is configured to determine a first CSI based on an offset value and the first reference value.

In one possible implementation, the transceiver 505 is further configured to: and sending second information to the terminal equipment, wherein the second information is used for determining the first reference value.

In one possible implementation, the second information indicates the first reference value; or, the second information indicates a second reference value used to determine the first reference value; or, the second information indicates a first candidate value set, the first candidate value set including a second reference value used to determine the first reference value; alternatively, the second information indicates a second set of candidate values, the second set of candidate values including the first reference value.

In one possible implementation, the second CSI satisfies at least one of:

the second CSI is the CSI closest to the first CSI in time before the reporting time of the first CSI; or the second CSI is the CSI closest to the PDSCH in time before the PDSCH corresponding to the first CSI; or the target BLER related to the second CSI is the same as the target BLER adopted by the first CSI; or the ReportConfigId of the second CSI is associated with the ReportConfigId of the first CSI, or the CSI-resourceConfigId of the second CSI is associated with the CSI-resourceConfigId of the first CSI, or the nzp-CSI-resourceSetId of the second CSI is associated with the nzp-CSI-resourceSetId of the first CSI.

In one possible implementation, the transceiver 505 is further configured to: and sending first indication information and/or second indication information to the terminal equipment, wherein the first indication information is used for indicating the first BLER, and the second indication information is used for indicating the second BLER.

It should be understood that the processor 501 in the embodiment of the present application may be implemented by a processing unit or a processing module, and the transceiver 505 may be implemented by a transceiver module or a communication interface.

The present application provides a terminal device (referred to as UE for convenience of description) that can be used in the foregoing embodiments. The terminal device comprises corresponding means, units and/or circuitry to implement the UE functionality described in the embodiment shown in fig. 4. For example, the terminal device includes a transceiver module for supporting the terminal device to implement a transceiver function, and a processing module for supporting the terminal device to process a signal.

Fig. 6 is a schematic structural diagram of a terminal device according to an embodiment of the present application.

The terminal device 600 may be adapted to the system shown in fig. 1. For convenience of explanation, fig. 6 shows only the main components of the terminal apparatus 600. As shown in fig. 6, the terminal apparatus 600 includes a processor, a memory, a control circuit, an antenna, and an input-output device. The processor is mainly used for processing a communication protocol and communication data, controlling the entire terminal device 600, executing a software program, and processing data of the software program. The memory is primarily used for storing software programs and data. The control circuit is mainly used for converting baseband signals and radio frequency signals and processing the radio frequency signals. The antenna is mainly used for receiving and transmitting radio frequency signals in the form of electromagnetic waves. Input and output devices, such as touch screens, display screens, microphones, keyboards, etc., are mainly used for receiving data input by users and outputting data to users.

Taking the terminal device 600 as a mobile phone as an example, when the terminal device 600 is powered on, the processor may read the software program in the storage unit, interpret and execute the instruction of the software program, and process the data of the software program. When data needs to be sent wirelessly, the processor performs baseband processing on the data to be sent and outputs baseband signals to the control circuit, and the control circuit performs radio frequency processing on the baseband signals and sends the radio frequency signals to the outside in the form of electromagnetic waves through the antenna. When data is transmitted to the terminal device 600, the control circuit receives a radio frequency signal through the antenna, converts the radio frequency signal into a baseband signal, and outputs the baseband signal to the processor, and the processor converts the baseband signal into data and processes the data.

Those skilled in the art will appreciate that fig. 6 shows only one memory and processor for the sake of illustration. In some embodiments, terminal device 600 may include multiple processors and memories. The memory may also be referred to as a storage medium or a storage device, and the like, which is not limited in this respect in the embodiment of the present invention.

As an alternative implementation manner, the processor may include a baseband processor and a central processing unit, the baseband processor is mainly used for processing the communication protocol and the communication data, and the central processing unit is mainly used for controlling the whole terminal device 600, executing the software program, and processing the data of the software program. The processor in fig. 6 integrates the functions of the baseband processor and the central processing unit, and those skilled in the art will understand that the baseband processor and the central processing unit may also be independent processors, and are interconnected through a bus or the like. The terminal device 600 may include a plurality of baseband processors to accommodate different network systems, the terminal device 600 may include a plurality of central processors to enhance its processing capability, and various components of the terminal device 600 may be connected by various buses. The baseband processor can also be expressed as a baseband processing circuit or a baseband processing chip. The central processing unit can also be expressed as a central processing circuit or a central processing chip. The function of processing the communication protocol and the communication data may be built in the processor, or may be stored in the storage unit in the form of a software program, and the software program is executed by the processor to realize the baseband processing function.

In one example, the antenna and the control circuit having the transceiving function may be regarded as the transceiving unit 66 of the terminal device 600, and the processor having the processing function may be regarded as the processing unit 620 of the terminal device 600. As shown in fig. 6, the terminal device 600 includes a transceiving unit 610 and a processing unit 620. A transceiver unit may also be referred to as a transceiver, a transceiving device, etc. Optionally, a device for implementing a receiving function in the transceiver unit 610 may be regarded as a receiving unit, and a device for implementing a transmitting function in the transceiver unit 610 may be regarded as a transmitting unit, that is, the transceiver unit 610 includes a receiving unit and a transmitting unit. For example, the receiving unit may also be referred to as a receiver, a receiving circuit, etc., and the sending unit may be referred to as a transmitter, a transmitting circuit, etc.

The embodiment of the present application further provides a network device, which may be used in the foregoing embodiments. The network device comprises means (means), units and/or circuits to implement the functionality of the network device described in the embodiment shown in fig. 4. For example, the network device includes a transceiver module for supporting the terminal device to implement a transceiver function, and a processing module for supporting the network device to process the signal. It is to be understood that the first network device and the second network device are interchangeable with respect to a certain UE or UEs and with respect to other UEs.

Fig. 7 shows a schematic structural diagram of a network device according to an embodiment of the present application. As shown in fig. 7, network device 20 may be suitable for use in the system shown in fig. 1. The network device 20 is, for example, the network device shown in fig. 1. The network device 20 may function as a first network device for one or some UEs, or may function as a second network device for one or some UEs. The network device includes: baseband device 201, rf device 202, antenna 203. In the uplink direction, rf apparatus 202 receives information transmitted by the terminal device through antenna 203, and transmits the information transmitted by the terminal device to baseband apparatus 201 for processing. In the downlink direction, the baseband device 201 processes the information of the terminal device and sends the information to the radio frequency device 202, and the radio frequency device 202 processes the information of the terminal device and sends the information to the terminal device through the antenna 203.

The baseband device 201 includes one or more processing units 2011, a storage unit 2012, and an interface 2013. Wherein the processing unit 2011 is configured to support the network device to perform the functions of the network device in the above method embodiments. The storage unit 2012 stores software programs and/or data. Interface 2013 is used to exchange information with RF device 202 and includes interface circuitry for the input and output of information. In one implementation, the processing unit is an integrated circuit, such as one or more ASICs, or one or more DSPs, or one or more FPGAs, or a combination of these types of integrated circuits. These integrated circuits may be integrated together to form a chip. The memory unit 2012 and the processing unit 2011 may be located in the same chip, i.e., on-chip memory devices. Alternatively, the memory unit 2012 and the processing unit 2011 can be on a different chip than the processing unit 2011, i.e., an off-chip memory device. The storage unit 2012 may be a single memory or a combination of multiple memories or storage elements.

A network device may implement some or all of the steps in the above-described method embodiments in the form of one or more processing unit schedulers. For example to implement the corresponding functionality of the network device in fig. 4. The one or more processing units may support the wireless access technology of the same type of system, and may also support wireless access systems of different types of systems.

When the communication device is a chip-like device or circuit, the device may comprise a transceiver unit and a processing unit. The transceiving unit can be an input-output circuit and/or a communication interface; the processing unit is an integrated processor or microprocessor or integrated circuit.

The embodiment of the present application further provides a communication system, and specifically, the communication system includes a network device and a terminal device, or may further include more network devices and a plurality of terminal devices. Illustratively, the communication system includes a network device and a terminal device for implementing the related functions of fig. 4 described above.

The network devices are respectively configured to implement the functions of the relevant network part of fig. 4 described above. The terminal device is configured to implement the function of the terminal device related to fig. 4. Please refer to the related description in the above method embodiments, which is not repeated herein.

Also provided in an embodiment of the present application is a computer-readable storage medium, which includes instructions that, when executed on a computer, cause the computer to perform the method performed by the network device in fig. 4; or when run on a computer, cause the computer to perform the method performed by the terminal device of fig. 4.

Also provided in an embodiment of the present application is a computer program product, which includes instructions that, when executed on a computer, cause the computer to perform the method performed by the network device in fig. 4; or when run on a computer, cause the computer to perform the method performed by the terminal device of fig. 4.

The embodiment of the application provides a chip system, which comprises a processor and a memory, and is used for realizing the functions of network equipment or a terminal in the method; or for implementing the functions of the network device and the terminal in the foregoing methods. The chip system may be formed by a chip, and may also include a chip and other discrete devices.

It should be understood that, in the various embodiments of the present application, the sequence numbers of the above-mentioned processes do not imply any order of execution, and the order of execution of the processes should be determined by their functions and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

Those of ordinary skill in the art will appreciate that the various illustrative logical blocks and steps (step) described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It can be clearly understood by those skilled in the art that, for convenience and simplicity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the methods described in the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a read-only memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.

Claims

1. A method for feeding back channel state information, comprising:

determining first Channel State Information (CSI);

and sending first information to a network device, wherein the first information is used for indicating an offset value, and the offset value is used for indicating a difference value between a first reference value and the first CSI.

2. The method of claim 1, wherein the method further comprises:

receiving second information from the network device, the second information being used to determine the first reference value.

3. The method of claim 2, wherein the second information indicates the first reference value; alternatively, the first and second liquid crystal display panels may be,

the second information indicates a second reference value used to determine the first reference value; alternatively, the first and second electrodes may be,

the second information indicates a first candidate value set including a second reference value used to determine the first reference value; alternatively, the first and second liquid crystal display panels may be,

the second information indicates a second set of candidate values, the second set of candidate values including the first reference value.

4. The method of claim 1, wherein the method further comprises:

determining second CSI, the second CSI to be used for determining the first reference value, the second CSI to be related to the first CSI.

5. The method of claim 4, wherein the second CSI satisfies at least one of:

the second CSI is the CSI closest to the PDSCH in time before the PDSCH corresponding to the first CSI; alternatively, the first and second electrodes may be,

the target block error rate (BLER) associated with the second CSI is the same as the target BLER adopted by the first CSI; alternatively, the first and second electrodes may be,

6. The method of claim 4 or 5, wherein the second CSI is used for determining the first reference value, comprising:

the second CSI corresponds to a wideband CQI, and the wideband CQI is used for determining the first reference value; alternatively, the first and second electrodes may be,

the second CSI corresponds to a wideband CQI, the wideband CQI is a second reference value Y, and the second reference value is used for determining the first reference value Y; alternatively, the first and second electrodes may be,

the sub-band CQI corresponding to the second CSI and at least one sub-band CQI corresponding to the PDSCH corresponding to the first CSI are used for determining the first reference value.

7. The method of claim 1, wherein the determining the first CSI comprises:

receiving first indication information and/or second indication information, wherein the first indication information is used for indicating a first BLER, and the second indication information is used for indicating a second BLER;

determining a target BLER, the target BLER being the first BLER or the second BLER;

and determining the first CSI according to the target BLER.

8. The method of claim 7, wherein determining the target BLER comprises:

receiving the first indication information, not receiving the second indication information, and determining that the target BLER is the first BLER; alternatively, the first and second liquid crystal display panels may be,

receiving the second indication information, not receiving the first indication information, and determining the target BLER as the second BLER; alternatively, the first and second electrodes may be,

and receiving the first indication information and the second indication information, and determining that the target BLER is the second BLER.

9. The method according to claim 7 or 8, wherein the second indication information is downlink control information, DCI.

10. The method of claim 7 or 8, wherein the first indication information is used for indicating a CQI index table, the CQI index table being associated with one BLER; or, the first indication information is used to indicate an MCS index table, and the MCS index table is associated with one BLER.

11. The method of claim 1, wherein the first CSI is determined based on a first PDSCH that is a retransmitted PDSCH.

12. The method of claim 11, wherein the first reference value is determined based on the first PDSCH.

13. The method of claim 12, wherein the first reference value is determined based on the first PDSCH, comprising:

the first reference value is determined according to the spectral efficiency corresponding to the first PDSCH.

14. The method of claim 11, wherein the first reference value is determined based on a second PDSCH, the second PDSCH being an initially transmitted PDSCH corresponding to the first PDSCH.

15. The method of claim 11, wherein a terminal device does not receive an initial-transmission PDSCH corresponding to the first PDSCH, and wherein the first information is used to indicate a first state, or wherein the offset value is used to indicate the first state, and wherein the first state is used to indicate that the first CSI cannot be obtained.

16. A method for feeding back channel state information, comprising:

17. The method of claim 16, wherein the method further comprises:

and sending second information to the terminal equipment, wherein the second information is used for determining the first reference value.

18. The method of claim 17, wherein the second information indicates the first reference value; alternatively, the first and second electrodes may be,

19. The method of claim 16, wherein the first reference value is determined by second CSI, the second CSI being related to the first CSI.

20. The method of claim 19, wherein the second CSI satisfies at least one of:

the target BLER associated with the second CSI is the same as the target BLER adopted by the first CSI; alternatively, the first and second electrodes may be,

21. The method of claim 19 or 20, wherein the first reference value is determined by the second CSI, comprising:

the first reference value is determined by a second reference value determined by the wideband CQI corresponding to the second CSI; alternatively, the first and second electrodes may be,

22. The method of claim 16, wherein the method further comprises:

and sending first indication information and/or second indication information to the terminal equipment, wherein the first indication information is used for indicating a first BLER, and the second indication information is used for indicating a second BLER.

23. The method of claim 22, wherein the second indication information is Downlink Control Information (DCI).

24. The method of claim 22, wherein the first indication information is used for indicating a CQI index table, the CQI index table being associated with one BLER; or, the first indication information is used to indicate an MCS index table, and the MCS index table is associated with one BLER.

25. The method of claim 16, wherein the first CSI is determined based on a first PDSCH, the first PDSCH being a retransmitted PDSCH.

26. The method of claim 25, wherein the first reference value is determined based on the first PDSCH.

27. The method of claim 26, wherein the first reference value is determined based on the first PDSCH, comprising:

28. The method of claim 25, wherein the first reference value is determined based on a second PDSCH, the second PDSCH being an initially transmitted PDSCH corresponding to the first PDSCH.

29. The method of claim 25, wherein the first information is used for indicating a first state, or wherein the offset value is used for indicating the first state, and wherein the first state is used for indicating that the first CSI cannot be obtained, and wherein a terminal device does not receive an initial PDSCH corresponding to the first PDSCH.

30. A communications device comprising a processor and interface circuitry for receiving and transmitting signals from or sending signals to a communications device other than the communications device, the processor being operable by logic circuitry or executing code instructions to implement the method of any one of claims 1 to 15; alternatively, the processor is used to implement the method of any one of claims 16 to 29 by logic circuits or executing code instructions.

31. A computer-readable storage medium, characterized in that it stores a computer program which, when executed, implements the method according to any one of claims 1 to 15; or, when said computer program is run, implementing a method as claimed in any one of claims 1 to 15.