Channel state information (CSI) feedback method and apparatus, terminal and network-side device

Abstract

The application discloses a channel state information (CSI) feedback method and device, a terminal and a network side equipment, and belongs to the technical field of communication. The method of the application embodiment comprises the following steps: a terminal determines N channel state information reference signals (CSI-RSs) to be measured; N is an integer greater than 1; the terminal measures the N CSI-RSs to obtain CSI; wherein the CSI comprises a transmission rank, beam indexes corresponding to P CSI-RSs, and a bit map corresponding to the P CSI-RSs, wherein the bit map is used for indicating coefficients of beams of the CSI-RSs which need to be fed back after frequency domain compression; P is an integer less than or equal to N; and the terminal sends the CSI to a network side equipment.

Description

Technical Field

[0001] This application belongs to the field of communication technology, specifically relating to a channel state information (CSI) feedback method, apparatus, terminal, and network-side equipment. Background Technology

[0002] The current technology supports Type II Channel State Information (Type II CSI). The terminal performs measurements based on the configured Channel State Information Reference Signal (CSI-RS) and feeds back multiple beam indices and amplitude and phase information for each frequency subband corresponding to each beam according to the relevant configuration.

[0003] Current technology further supports the evolution of Type II CSI. Based on Type II CSI, the precoding matrix is ​​compressed in the frequency domain and then fed back. The feedback information includes a bit map, which indicates that the coefficient corresponding to each beam after compression in the frequency domain is 0 or 1. 0 means that the amplitude and phase corresponding to the coefficient are not fed back, and 1 means that the amplitude and phase corresponding to the coefficient are fed back.

[0004] Current CSI feedback methods are only applicable to single-point transmission systems. In multi-point transmission systems, current technology does not yet support how to configure channel measurement pilots or how terminals can provide Type II CSI feedback. Summary of the Invention

[0005] This application provides a Channel State Information (CSI) feedback method, apparatus, terminal, and network-side device, which can solve the problem of how to feedback CSI in a multi-point transmission system.

[0006] Firstly, a Channel State Information (CSI) feedback method is provided, including:

[0007] The terminal determines N Channel State Information Reference Signals (CSI-RS) to be measured; N is an integer greater than 1.

[0008] The terminal measures the N CSI-RS to obtain the CSI; wherein, the CSI includes: transmission rank, beam index corresponding to each of the P CSI-RS, and bit map corresponding to the P CSI-RS, the bit map being used to indicate the coefficients of the feedback beam of the CSI-RS after frequency domain compression; P is an integer less than or equal to N;

[0009] The terminal sends the CSI to the network-side device.

[0010] Secondly, a Channel State Information (CSI) feedback method is provided, including:

[0011] The network-side device receives the CSI fed back by the terminal after measuring N CSI-RS. The CSI includes: transmission rank, beam index corresponding to each of the P CSI-RS, and bit map corresponding to the P CSI-RS. The bit map is used to indicate the coefficients of the CSI-RS feedback beam after frequency domain compression. N is an integer greater than 1. P is an integer less than or equal to N.

[0012] Thirdly, a Channel State Information (CSI) feedback device is provided, comprising:

[0013] The first determining module is used to determine the N Channel State Information Reference Signals (CSI-RS) to be measured; N is an integer greater than 1.

[0014] The second determining module is used to measure the N CSI-RS to obtain the CSI; wherein the CSI includes: transmission rank, beam index corresponding to each of the P CSI-RS, and bit map corresponding to the P CSI-RS, the bit map being used to indicate the coefficients of the feedback beam of the CSI-RS after frequency domain compression; P is an integer less than or equal to N;

[0015] The sending module is used to send the CSI to the network-side device.

[0016] Fourthly, a Channel State Information (CSI) feedback device is provided, comprising:

[0017] The receiving module is used to receive the CSI fed back by the terminal after measuring N CSI-RS. The CSI includes: transmission rank, beam index corresponding to each of the P CSI-RS, and bit map corresponding to the P CSI-RS. The bit map is used to indicate the coefficients of the feedback beam of the CSI-RS after frequency domain compression; N is an integer greater than 1; P is an integer less than or equal to N.

[0018] Fifthly, a terminal is provided, the terminal including a processor and a memory, the memory storing a program or instructions executable on the processor, the program or instructions, when executed by the processor, implementing the steps of the method as described in the first aspect.

[0019] In a sixth aspect, a terminal is provided, including a processor and a communication interface, wherein the processor is used to determine N Channel State Information Reference Signals (CSI-RS) to be measured; N is an integer greater than 1; and to measure the N CSI-RS to obtain a CSI; wherein the CSI includes: a transmission rank, beam indices corresponding to P CSI-RS respectively, and a bit map corresponding to the P CSI-RS, the bit map being used to indicate the coefficients of the feedback beam of the CSI-RS after frequency domain compression; P is an integer less than or equal to N; and the communication interface is used to send the CSI to a network-side device.

[0020] In a seventh aspect, a network-side device is provided, the network-side device including a processor and a memory, the memory storing a program or instructions executable on the processor, the program or instructions, when executed by the processor, implementing the steps of the method as described in the second aspect.

[0021] Eighthly, a network-side device is provided, including a processor and a communication interface, wherein the communication interface is used to receive CSI fed back by a terminal after measuring N CSI-RS, the CSI including: transmission rank, beam indices corresponding to P CSI-RS respectively, and bit map corresponding to P CSI-RS, the bit map being used to indicate the coefficients of the feedback beam of the CSI-RS after frequency domain compression; N is an integer greater than 1; P is an integer less than or equal to N.

[0022] A ninth aspect provides a communication system comprising: a terminal and a network-side device, wherein the terminal is configured to perform the steps of the Channel State Information (CSI) feedback method as described in the first aspect, and the network-side device is configured to perform the steps of the Channel State Information (CSI) feedback method as described in the second aspect.

[0023] In a tenth aspect, a readable storage medium is provided, on which a program or instructions are stored, which, when executed by a processor, implement the steps of the method described in the first aspect, or implement the steps of the method described in the second aspect.

[0024] Eleventhly, a chip is provided, the chip including a processor and a communication interface, the communication interface being coupled to the processor, the processor being used to run programs or instructions to implement the method as described in the first aspect, or to implement the method as described in the second aspect.

[0025] In a twelfth aspect, a computer program / program product is provided, which is stored in a storage medium and is executed by at least one processor to implement the steps of the method as described in the first aspect, or to implement the steps of the method as described in the second aspect.

[0026] In this embodiment of the application, in a multi-point transmission system, after a terminal measures multiple CSI-RS, it reports a CSI. The CSI carries a bit map corresponding to the CSI-RS determined by the terminal according to the network configuration or a pre-agreed mapping rule. The network-side device can determine the mapping relationship between the bit map in the CSI and the coefficients of the feedback beam of the CSI-RS after frequency domain compression according to the corresponding mapping rule, thereby achieving consistent understanding of the bit map between the terminal and the network-side device and improving the correct transmission efficiency of the CSI. Attached Figure Description

[0027] Figure 1 A block diagram illustrating a wireless communication system to which embodiments of this application may be applied;

[0028] Figure 2 This is a flowchart illustrating one of the steps of the Channel State Information (CSI) feedback method provided in an embodiment of this application.

[0029] Figure 3 This is the second flowchart illustrating the steps of the Channel State Information (CSI) feedback method provided in the embodiments of this application.

[0030] Figure 4 This diagram illustrates an example of a multipoint transmission system provided in Example 1 of this application.

[0031] Figure 5 This is one of the structural schematic diagrams of the Channel State Information (CSI) feedback device provided in the embodiments of this application;

[0032] Figure 6 This is the second schematic diagram illustrating the structure of the Channel State Information (CSI) feedback device provided in the embodiments of this application.

[0033] Figure 7 This is a schematic diagram of the structure of the communication device provided in the embodiments of this application;

[0034] Figure 8 This is a schematic diagram of the structure of the terminal provided in the embodiments of this application;

[0035] Figure 9 This is a schematic diagram illustrating the structure of the network-side device provided in the embodiments of this application. Detailed Implementation

[0036] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0037] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first" and "second" are generally of the same class, not limited in number; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0038] It is worth noting that the technologies described in this application are not limited to Long Term Evolution (LTE) / LTE-Advanced (LTE-A) systems, but can also be used in other wireless communication systems, such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single-carrier Frequency Division Multiple Access (SC-FDMA), and other systems. The terms "system" and "network" in this application are often used interchangeably, and the described technologies can be used with the systems and radio technologies mentioned above, as well as with other systems and radio technologies. The following description describes New Radio (NR) systems for illustrative purposes, and NR terminology is used in most of the following description; however, these technologies can also be applied to applications beyond NR systems, such as 6th generation (6G) radio systems. th Generation 6G communication system.

[0039] Figure 1This diagram illustrates a block diagram of a wireless communication system applicable to embodiments of this application. The wireless communication system includes a terminal 11 and a network-side device 12. Terminal 11 can be a mobile phone, tablet computer, laptop computer, personal digital assistant (PDA), handheld computer, netbook, ultra-mobile personal computer (UMPC), mobile internet device (MID), augmented reality (AR) / virtual reality (VR) device, robot, wearable device, vehicle-mounted device (VUE), pedestrian terminal (PUE), smart home (home devices with wireless communication capabilities, such as refrigerators, televisions, washing machines, or furniture), game console, personal computer (PC), ATM, or self-service machine, etc. Wearable devices include: smartwatches, smart bracelets, smart headphones, smart glasses, smart jewelry (smart bracelets, smart chains, smart rings, smart necklaces, smart anklets, smart anklets, etc.), smart wristbands, smart clothing, etc. It should be noted that the specific type of terminal 11 is not limited in this embodiment. Network-side equipment 12 may include access network equipment or core network equipment. Access network equipment 12 may also be referred to as radio access network equipment, radio access network (RAN), radio access network function, or radio access network unit. Access network equipment 12 may include base stations, WLAN access points, or WiFi nodes, etc. Base stations may be referred to as Node B, evolved Node B (eNB), access point, base transceiver station (BTS), radio base station, radio transceiver, Basic Service Set (BSS), Extended Service Set (ESS), home B node, home evolved B node, Transmitting Receiving Point (TRP), or any other suitable term in the field, as long as the same technical effect is achieved. The base station is not limited to specific technical terms. It should be noted that in this application embodiment, only a base station in an NR system is used as an example for description, and the specific type of base station is not limited.

[0040] The Channel State Information (CSI) feedback method, apparatus, terminal, and network-side equipment provided in this application will be described in detail below with reference to the accompanying drawings and through some embodiments and application scenarios.

[0041] like Figure 2 As shown in the figure, this application provides a Channel State Information (CSI) feedback method, including:

[0042] Step 201: The terminal determines the N Channel State Information Reference Signals (CSI-RS) to be measured; N is an integer greater than 1.

[0043] Step 202: The terminal measures the N CSI-RS to obtain the CSI; wherein the CSI includes: transmission rank, beam index corresponding to each of the P CSI-RS, and bit map corresponding to the P CSI-RS, the bit map being used to indicate the coefficients of the CSI-RS after frequency domain compression; P is an integer less than or equal to N;

[0044] Step 203: The terminal sends the CSI to the network-side device.

[0045] In this embodiment of the application, the number of ports of each CSI-RS may be the same or different, and the number of ports of each CSI-RS is a positive integer greater than 1.

[0046] In at least one embodiment of this application, the above-mentioned CSI is an evolved Type II CSI (which may be abbreviated as eType II CSI), that is, the terminal compresses the precoding matrix corresponding to the feedback beam of the CSI-RS in the frequency domain and then feeds it back in the CSI. That is, the feedback CSI includes P bit maps corresponding to the CSI-RS. The bit map is used to indicate that the coefficient of the feedback beam of the CSI-RS after frequency domain compression is 0 or 1. 0 indicates that the amplitude and phase corresponding to the coefficient are not fed back, and 1 indicates that the amplitude and phase corresponding to the coefficient are fed back.

[0047] As an optional embodiment, P can be equal to N, that is, all N CSI-RS measured by the terminal are fed back in the CSI.

[0048] As another optional embodiment, P can be less than N, meaning the terminal flexibly selects a portion of the N CSI-RSs measured to provide feedback in the CSI. Optionally, when P is less than N, the CSI further includes: identification information of the P CSI-RSs, such as the CSI-RS index (CRI) of the P CSI-RSs. The CRI indicates the CSI-RS selected by the terminal. This method can also be described as the terminal explicitly indicating its flexibly selected CSI-RSs.

[0049] As another optional embodiment, the terminal can also use an implicit indication method to indicate its flexibly selected CSI-RS, that is, P equals N, but in the bit map corresponding to the N CSI-RS, all bits corresponding to the unselected CSI-RS are set to 0.

[0050] In at least one embodiment of this application, step 201 includes:

[0051] The terminal receives N CSI-RS configured by the network-side device; that is, no activation operation is required on the network side, and the terminal directly measures the configured N CSI-RS.

[0052] Alternatively, step 201 includes:

[0053] The terminal receives M CSI-RS configured by the network-side device and receives activation signaling; the activation signaling is used to activate N CSI-RS among the M CSI-RS; where M is an integer greater than N. For example, the activation signaling can be MAC CE (Medium Access Control Control Element) or DCI (Downlink Control Information).

[0054] In this embodiment of the application, the method further includes:

[0055] The terminal receives the total number of beams that need to be fed back by the N CSI-RS configured by the network-side device, and determines the number of beams that each CSI-RS needs to feed back based on the total number of beams; or, the terminal receives the number of beams that each CSI-RS needs to feed back based on the network-side device.

[0056] The terminal determines the beam index corresponding to each of the P CSI-RS based on the number of beams that each CSI-RS needs to feed back.

[0057] In other words, the network-side equipment can further configure the number of beams (basis vectors) required by the terminal. This can be configured to have a total number of L, or the number of beams can be configured separately for each of the N CSI-RS, such as L1, L2, ..., L. N When the number of beams is configured to a total of L, the terminal maps the total number of beams L to N CSI-RS according to predefined rules.

[0058] For example, if N CSI-RSs have the same number of ports, the number of beams corresponding to each CSI-RS is the same (L is divisible by N), or the number of beams corresponding to the last CSI-RS is different from the other CSI-RSs (L is not divisible by N). As another example, if the N CSI-RSs have different numbers of ports, the number of beams is determined according to the number of ports of each CSI-RS. For instance, if CSI-RS 1 has 4 ports and CSI-RS 2 has 8 ports, then the number of beams corresponding to CSI-RS 2 is twice the number of beams corresponding to CSI-RS 1.

[0059] In at least one embodiment of this application, the method further includes:

[0060] The terminal receives one or more values ​​of the subband precoding matrix indicator (PMI) configured by the network-side device.

[0061] The terminal performs frequency domain compression on the precoding matrices corresponding to the P CSI-RS according to one or more values ​​of the subband PMI, and determines the coefficients of the feedback beams of the P CSI-RS after frequency domain compression.

[0062] It should be noted that if the network-side device is configured with one value for the subband PMI, N CSI-RS can share that value; or, if the network-side device is configured with multiple values ​​for the subband PMI, each CSI-RS corresponds to one value; optionally, at least two CSI-RSs may correspond to different values ​​for the subband PMI.

[0063] Optionally, when the number of beams is configured to a total of L, the network-side device only configures one value for the sub-band PMI; when the number of beams is configured for each of the N CSI-RS, the network-side device can configure a shared value for the sub-band PMI or configure N values ​​for the sub-band PMI separately (i.e., one value for PMI corresponds to one CSI-RS).

[0064] In at least one embodiment of this application, the method further includes:

[0065] The bit map corresponding to the P CSI-RS includes: a bit map that maps the coefficients of the feedback beams of the P CSI-RS after frequency domain compression;

[0066] Alternatively, the bit map corresponding to the P CSI-RS includes: multiple bit maps, each bit map mapping the coefficients of the feedback beam of a CSI-RS after frequency domain compression;

[0067] The bit map corresponding to the P CSI-RS is determined by the terminal according to network configuration or pre-agreed upon.

[0068] For example, the network-side device can be configured to allow the terminal to feed back a bitmap corresponding to multiple CSI-RS; or, the network-side device can be configured to allow the terminal to feed back a bitmap corresponding to each CSI-RS, i.e., configure the terminal to feed back multiple bitmaps. Optionally, if the network-side device does not configure the number of bitmaps fed back, the default is that the terminal feeds back one bitmap.

[0069] For example, "pre-agreed" can be understood as the terminal and network-side equipment pre-determining, through signaling interaction, the bitmaps corresponding to P CSI-RS, including one or more bitmaps; or it can be understood as a protocol agreement specifying that the bitmaps corresponding to P CSI-RS include one or more bitmaps; that is, determining that the terminal will feed back one bitmap corresponding to multiple CSI-RS; or, determining that the terminal will feed back the bitmap corresponding to each CSI-RS, that is, determining that the terminal will feed back multiple bitmaps.

[0070] Furthermore, in at least one embodiment of this application, the method further includes:

[0071] If the network-side device is configured to provide feedback to a single bit map corresponding to multiple CSI-RS, or if the network side is not configured, the terminal will map the coefficients of the feedback beams of P CSI-RS after frequency domain compression onto a single bit map according to the network configuration or pre-agreed mapping rules.

[0072] For example, if P = 4, representing the first CSI-RS, second CSI-RS, third CSI-RS, and fourth CSI-RS respectively; then the terminal maps all the coefficients of the feedback beams of the first CSI-RS, second CSI-RS, third CSI-RS, and fourth CSI-RS after frequency domain compression onto a single bit map, resulting in a single bit map.

[0073] Alternatively, in at least one embodiment of this application, the method further includes:

[0074] When the network-side equipment is configured to provide the bit map corresponding to each CSI-RS, the terminal maps the coefficients of the feedback beam of each CSI-RS after frequency domain compression to the corresponding bit map according to the network configuration or pre-agreed mapping rules.

[0075] For example, if P = 4, representing the first CSI-RS, second CSI-RS, third CSI-RS, and fourth CSI-RS respectively; then the terminal maps the coefficients of the feedback beam of the first CSI-RS after frequency domain compression to a bit map, the terminal maps the coefficients of the feedback beam of the second CSI-RS after frequency domain compression to a bit map, the terminal maps the coefficients of the feedback beam of the third CSI-RS after frequency domain compression to a bit map, and the terminal maps the coefficients of the feedback beam of the fourth CSI-RS after frequency domain compression to a bit map, resulting in 4 bit maps.

[0076] It should be noted that if the transmission rank included in CSI is greater than 1, it indicates that CSI-RS corresponds to at least two transmission layers. In this case, the bit map corresponding to each transmission layer can be fed back in CSI separately, or it can be cascaded according to certain rules and then fed back in CSI.

[0077] In at least one embodiment of this application, the mapping rule includes at least one of the following:

[0078] Rule 1: Map CSI-RS to the bit map according to their priority order; the priority of CSI-RS can be determined by signal strength (such as RSRP).

[0079] Rule 2: Map the data onto the bitmap according to the index size order of CSI-RS;

[0080] Rule 3: Map the data onto the bitmap according to the beam index size order corresponding to CSI-RS;

[0081] Rule 4: Map the coefficients of the CSI-RS feedback beam after frequency domain compression onto the bit map in the order of their identifiers.

[0082] Rule 5: Map the data onto the bitmap according to the size order of the transport layer identifiers corresponding to CSI-RS;

[0083] Rule 6: Map the data onto the bitmap according to the transport layer priority order corresponding to CSI-RS.

[0084] The priority of rules 1-6 can also be determined by network configuration or pre-agreed upon. If a rule needs to be discarded (e.g., due to insufficient resources or resource conflicts), the rule mapped later will be discarded first. However, it is necessary to ensure that the terminal and network-side devices have a consistent understanding of each rule and its priority.

[0085] For example, when the rank of the feedback is 1, and the number of beams corresponding to each CSI-RS is greater than 1, the mapping rule is: first rule 2, then rule 3, then rule 4. Specifically, the sequential correspondence of each bit in the bit map can be: the first coefficient of the first beam of the first CSI-RS, the second coefficient of the first beam of the first CSI-RS, ..., the first coefficient of the second beam of the first CSI-RS, the second coefficient of the second beam of the first CSI-RS, ..., the first coefficient of the first beam of the second CSI-RS, the second coefficient of the first beam of the second CSI-RS, ..., the first coefficient of the second beam of the second CSI-RS, the second coefficient of the first beam of the second CSI-RS, ...

[0086] For example, when the rank of the feedback is 1, and the number of beams corresponding to each CSI-RS is greater than 1, the mapping rule is to prioritize rule 4, then rule 3. Specifically, the corresponding relationship of each bit in the bit map can be: the first coefficient of the first beam of the first CSI-RS, the first coefficient of the second beam of the first CSI-RS, ..., the second coefficient of the first beam of the second CSI-RS, the second coefficient of the second beam of the second CSI-RS, ...

[0087] For example, when the rank of the feedback is greater than 1, and the number of beams corresponding to each CSI-RS is greater than 1, the mapping rule is: first rule 5, then rule 2, then rule 3, then rule 4. Specifically, the sequential correspondence of each bit in the bitmap can be: the first coefficient corresponding to the first layer of the first beam of the first CSI-RS, the second coefficient corresponding to the first layer of the first beam of the first CSI-RS, ..., the first coefficient corresponding to the first layer of the second beam of the first CSI-RS, the second coefficient corresponding to the first layer of the second beam of the first CSI-RS, ..., the first coefficient corresponding to the first layer of the first beam of the second CSI-RS, the second coefficient corresponding to the first layer of the first beam of the second CSI-RS, ..., the first coefficient corresponding to the first layer of the first beam of the second CSI-RS, the second coefficient corresponding to the first layer of the first beam of the second CSI-RS, ..., the first coefficient corresponding to the first layer of the first beam of the second CSI-RS, the first layer of the first beam of the second CSI-RS... The corresponding second coefficient, ..., the first coefficient corresponding to the second layer of the first beam of the first CSI-RS, the second coefficient corresponding to the second layer of the first beam of the first CSI-RS, ..., the first coefficient corresponding to the second layer of the second beam of the first CSI-RS, the second coefficient corresponding to the second layer of the second beam of the first CSI-RS, ..., the first coefficient corresponding to the second layer of the first beam of the second CSI-RS, the second coefficient corresponding to the second layer of the first beam of the second CSI-RS, ..., the first coefficient corresponding to the second layer of the second beam of the second CSI-RS, the second coefficient corresponding to the second layer of the first beam of the second CSI-RS, ...

[0088] In this embodiment of the application, in a multi-point transmission system, after a terminal measures multiple CSI-RS, it reports a CSI. The CSI carries a bit map corresponding to the CSI-RS determined by the terminal according to the network configuration or a pre-agreed mapping rule. The network-side device can determine the mapping relationship between the bit map in the CSI and the coefficients of the feedback beam of the CSI-RS after frequency domain compression according to the corresponding mapping rule, thereby achieving consistent understanding of the bit map between the terminal and the network-side device and improving the correct transmission efficiency of the CSI.

[0089] like Figure 3 As shown in the embodiments of this application, a Channel State Information (CSI) feedback method is also provided, including:

[0090] Step 301: The network-side device receives the CSI fed back by the terminal after measuring N CSI-RS. The CSI includes: transmission rank, beam index corresponding to each of the P CSI-RS, and bit map corresponding to the P CSI-RS. The bit map is used to indicate the coefficients of the CSI-RS feedback beam after frequency domain compression. N is an integer greater than 1. P is an integer less than or equal to N.

[0091] In this embodiment of the application, the number of ports of each CSI-RS may be the same or different, and the number of ports of each CSI-RS is a positive integer greater than 1.

[0092] In at least one embodiment of this application, the above-mentioned CSI is an evolved Type II CSI (which may be abbreviated as eType II CSI), that is, the terminal compresses the precoding matrix corresponding to the feedback beam of the CSI-RS in the frequency domain and then feeds it back in the CSI. That is, the feedback CSI includes P bit maps corresponding to the CSI-RS. The bit map is used to indicate that the coefficient of the feedback beam of the CSI-RS after frequency domain compression is 0 or 1. 0 indicates that the amplitude and phase corresponding to the coefficient are not fed back, and 1 indicates that the amplitude and phase corresponding to the coefficient are fed back.

[0093] As an optional embodiment, P can be equal to N, that is, all N CSI-RS measured by the terminal are fed back in the CSI.

[0094] As another optional embodiment, P can be less than N, meaning the terminal flexibly selects a portion of the N CSI-RSs measured to provide feedback in the CSI. Optionally, when P is less than N, the CSI further includes: identification information of the P CSI-RSs, such as the CSI-RS index (CRI) of the P CSI-RSs. The CRI indicates the CSI-RS selected by the terminal. This method can also be described as the terminal explicitly indicating its flexibly selected CSI-RSs.

[0095] As another optional embodiment, the terminal can also use an implicit indication method to indicate its flexibly selected CSI-RS, that is, P equals N, but in the bit map corresponding to the N CSI-RS, all bits corresponding to the unselected CSI-RS are set to 0.

[0096] In at least one embodiment of this application, the method further includes:

[0097] The network-side equipment configures N CSI-RS for the terminal; that is, no activation operation is required on the network side, and the terminal directly measures the configured N CSI-RS.

[0098] or,

[0099] The network-side device configures M CSI-RS for the terminal and sends an activation signaling message to the terminal. The activation signaling message is used to instruct the activation of N CSI-RS among the M CSI-RS, where M is an integer greater than N. For example, the activation signaling message can be MACCE (Medium Access Control Control Element) or DCI (Downlink Control Information).

[0100] In this embodiment of the application, the method further includes:

[0101] The total number of beams that the network-side equipment needs to feed back for N CSI-RS configurations for the terminal;

[0102] or,

[0103] The network-side equipment configures the number of beams that each CSI-RS needs to feed back for the terminal.

[0104] In other words, the network-side equipment can further configure the number of beams (basis vectors) required by the terminal. This can be configured to have a total number of L, or the number of beams can be configured separately for each of the N CSI-RS, such as L1, L2, ..., L. N When the number of beams is configured to a total of L, the terminal maps the total number of beams L to N CSI-RS according to predefined rules.

[0105] For example, if the number of ports of N CSI-RSs is the same, the number of beams corresponding to each CSI-RS is the same (L is divisible by N), or the number of beams corresponding to the last CSI-RS is different from the other CSI-RSs (L is not divisible by N). As another example, if the number of ports of N CSI-RSs is different, the number of beams corresponding to each CSI-RS is determined according to the number of ports. For instance, if CSI-RS 1 has 4 ports and CSI-RS 2 has 8 ports, then the number of beams corresponding to CSI-RS 2 is twice the number of beams corresponding to CSI-RS 1.

[0106] In at least one embodiment of this application, the method further includes:

[0107] The network-side equipment configures one or more values ​​of the subband precoding matrix indicator PMI for the terminal.

[0108] It should be noted that if the network-side device is configured with one value for the subband PMI, N CSI-RS can share that value; or, if the network-side device is configured with multiple values ​​for the subband PMI, each CSI-RS corresponds to a different value; optionally, different CSI-RS can correspond to different values ​​for the subband PMI.

[0109] Optionally, when the number of beams is configured to a total of L, the network-side device only configures one value for the sub-band PMI; when the number of beams is configured for each of the N CSI-RS, the network-side device can configure a shared value for the sub-band PMI or configure N values ​​for the sub-band PMI separately (i.e., one value for PMI corresponds to one CSI-RS).

[0110] In at least one embodiment of this application, the method further includes:

[0111] The network-side device configures the CSI fed back by the terminal to include one or more bitmaps;

[0112] Wherein, when the CSI includes a bit map, the bit map maps the frequency-domain compressed coefficients of the feedback beams of P CSI-RS; where the CSI includes multiple bit maps, each bit map maps the frequency-domain compressed coefficients of the feedback beams of one CSI-RS.

[0113] For example, the network-side device can be configured to allow the terminal to feed back a bitmap corresponding to multiple CSI-RS; or, the network-side device can be configured to allow the terminal to feed back a bitmap corresponding to each CSI-RS, i.e., configure the terminal to feed back multiple bitmaps. Optionally, if the network-side device does not configure the number of bitmaps fed back, the default is that the terminal feeds back one bitmap.

[0114] It should be noted that if the transmission rank included in CSI is greater than 1, it indicates that CSI-RS corresponds to at least two transmission layers. In this case, the bit map corresponding to each transmission layer can be fed back in CSI separately, or it can be cascaded according to certain rules and then fed back in CSI.

[0115] Furthermore, in at least one embodiment of this application, the method further includes:

[0116] The network-side device determines the mapping relationship between the bit map in the CSI and the coefficients of the feedback beam of the CSI-RS after frequency domain compression, according to the pre-agreed mapping rules.

[0117] The mapping rules include at least one of the following:

[0118] Rule 1: Map CSI-RS to the bit map according to their priority order; the priority of CSI-RS can be determined by signal strength (such as RSRP).

[0119] Rule 2: Map the data onto the bitmap according to the index size order of CSI-RS;

[0120] Rule 3: Map the data onto the bitmap according to the beam index size order corresponding to CSI-RS;

[0121] Rule 4: Map the coefficients of the CSI-RS feedback beam after frequency domain compression onto the bit map in the order of their identifiers.

[0122] Rule 5: Map the data onto the bitmap according to the size order of the transport layer identifiers corresponding to CSI-RS;

[0123] Rule 6: Map the data onto the bitmap according to the transport layer priority order corresponding to CSI-RS.

[0124] The priority of rules 1-6 can also be determined by network configuration or pre-agreed upon. If a rule needs to be discarded (e.g., due to insufficient resources or resource conflicts), the rule mapped later will be discarded first. However, it is necessary to ensure that the terminal and network-side devices have a consistent understanding of each rule and its priority.

[0125] For example, when the rank of the feedback is 1, and the number of beams corresponding to each CSI-RS is greater than 1, the mapping rule is: first rule 2, then rule 3, then rule 4. Specifically, the sequential correspondence of each bit in the bit map can be: the first coefficient of the first beam of the first CSI-RS, the second coefficient of the first beam of the first CSI-RS, ..., the first coefficient of the second beam of the first CSI-RS, the second coefficient of the second beam of the first CSI-RS, ..., the first coefficient of the first beam of the second CSI-RS, the second coefficient of the first beam of the second CSI-RS, ..., the first coefficient of the second beam of the second CSI-RS, the second coefficient of the first beam of the second CSI-RS, ...

[0126] For example, when the rank of the feedback is 1, and the number of beams corresponding to each CSI-RS is greater than 1, the mapping rule is to prioritize rule 4, then rule 3. Specifically, the corresponding relationship of each bit in the bit map can be: the first coefficient of the first beam of the first CSI-RS, the first coefficient of the second beam of the first CSI-RS, ..., the second coefficient of the first beam of the second CSI-RS, the second coefficient of the second beam of the second CSI-RS, ...

[0127] For example, when the rank of the feedback is greater than 1, and the number of beams corresponding to each CSI-RS is greater than 1, the mapping rule is: first rule 5, then rule 2, then rule 3, then rule 4. Specifically, the sequential correspondence of each bit in the bitmap can be: the first coefficient corresponding to the first layer of the first beam of the first CSI-RS, the second coefficient corresponding to the first layer of the first beam of the first CSI-RS, ..., the first coefficient corresponding to the first layer of the second beam of the first CSI-RS, the second coefficient corresponding to the first layer of the second beam of the first CSI-RS, ..., the first coefficient corresponding to the first layer of the first beam of the second CSI-RS, the second coefficient corresponding to the first layer of the first beam of the second CSI-RS, ..., the first coefficient corresponding to the first layer of the first beam of the second CSI-RS, the second coefficient corresponding to the first layer of the first beam of the second CSI-RS, ..., the first coefficient corresponding to the first layer of the first beam of the second CSI-RS, the first layer of the first beam of the second CSI-RS... The corresponding second coefficient, ..., the first coefficient corresponding to the second layer of the first beam of the first CSI-RS, the second coefficient corresponding to the second layer of the first beam of the first CSI-RS, ..., the first coefficient corresponding to the second layer of the second beam of the first CSI-RS, the second coefficient corresponding to the second layer of the second beam of the first CSI-RS, ..., the first coefficient corresponding to the second layer of the first beam of the second CSI-RS, the second coefficient corresponding to the second layer of the first beam of the second CSI-RS, ..., the first coefficient corresponding to the second layer of the second beam of the second CSI-RS, the second coefficient corresponding to the second layer of the first beam of the second CSI-RS, ...

[0128] In this embodiment of the application, in a multi-point transmission system, after a terminal measures multiple CSI-RS, it reports a CSI. The CSI carries a bit map corresponding to the CSI-RS determined by the terminal according to the network configuration or a pre-agreed mapping rule. The network-side device can determine the mapping relationship between the bit map in the CSI and the coefficients of the feedback beam of the CSI-RS after frequency domain compression according to the corresponding mapping rule, thereby achieving consistent understanding of the bit map between the terminal and the network-side device and improving the correct transmission efficiency of the CSI.

[0129] To more clearly describe the CSI feedback method provided in the embodiments of this application, several examples are given below.

[0130] Example 1

[0131] like Figure 4 As shown, the multipoint transmission system includes 8 transmission points (TRPs), namely TRP1, TRP2, TRP3, TRP4, TRP5, TRP6, TRP7, and TRP8.

[0132] The base station for UE 1 can be configured with M=8 CSI-RS pilots (CSI-RS1, CSI-RS2, CSI-RS3, CSI-RS4, CSI-RS5, CSI-RS6, CSI-RS7, CSI-RS8), and can further activate N=4 CSI-RS.

[0133] The base station for UE 2 can be configured with M=4 CSI-RS pilots (CSI-RS3, CSI-RS4, CSI-RS5, CSI-RS6), and can further activate N=4 CSI-RS.

[0134] For UE 3, the base station can be configured with M=2 CSI-RS pilots (CSI-RS7, CSI-RS8). The base station does not send an activation command, meaning that both are activated by default.

[0135] Example 2

[0136] Assuming that each CSI-RS pilot in the base station has the same number of ports and 4 CSI-RS are configured, and the base station is configured to provide L = 8 beams for terminal feedback, and each beam corresponds to 4 coefficients after frequency domain compression, and the rank of the feedback is 1, the values ​​of the coefficients corresponding to each beam after frequency domain compression are shown in Table 1:

[0137]

[0138]

[0139] Table 1

[0140] Among them, beam indices 1 and 2 correspond to the first CSI-RS, beam indices 3 and 4 correspond to the second CSI-RS, beam indices 5 and 6 correspond to the third CSI-RS, and beam indices 7 and 8 correspond to the fourth CSI-RS.

[0141] The bitmap of CSI is: 1010 0110 1111 1001 0101 0101 1010 0111, or the bitmap of CSI is: 10110010 01101101 11100011 00111101.

[0142] Alternatively, the coefficients for each beam after frequency domain compression are shown in Table 2:

[0143] Beam Index First coefficient Second coefficient Third coefficient Fourth coefficient 1 1 0 1 0 2 0 1 1 0 3 1 1 1 1 4 1 0 0 1 5 0 0 0 0 6 0 0 0 0 7 1 0 1 0 8 0 1 1 1

[0144] Table 2

[0145] In Table 2, beam indices 1 and 2 correspond to the first CSI-RS, beam indices 3 and 4 correspond to the second CSI-RS, beam indices 5 and 6 correspond to the third CSI-RS, and beam indices 7 and 8 correspond to the fourth CSI-RS. In Table 2, all coefficients corresponding to beams 5 and 6 are 0, indicating that the third CSI-RS was not selected in the terminal's feedback CSI.

[0146] The bitmap included in CSI is: 1010 0110 1111 1001 0000 0000 1010 0111; or the bitmap included in CSI is: 10110010 01100001 11100011 00110001.

[0147] Example 3

[0148] Assume that each CSI-RS pilot configured by the base station has the same number of ports and 4 CSI-RS are configured. The base station is configured to send back L1=2 beams, L2=4 beams, L3=2 beams, and L4=2 beams. After frequency domain compression, each beam corresponds to 4 coefficients, and the rank of the feedback is 1. Each CSI-RS sends back a bit map.

[0149] The coefficients for each beam after the first CSI-RS frequency domain compression are shown in Table 3:

[0150] Beam Index First coefficient Second coefficient Third coefficient Fourth coefficient 1 1 0 1 0 2 0 1 1 0

[0151] Table 3

[0152] The bitmap corresponding to the first CSI-RS is: 10100110, or 10011100.

[0153] The coefficients for each beam after the second CSI-RS frequency domain compression are shown in Table 4:

[0154]

[0155]

[0156] Table 4

[0157] The bitmap corresponding to the second CSI-RS is: 1010011011111001, or 1011011011100011.

[0158] The coefficients for each beam after the third CSI-RS frequency domain compression are shown in Table 5:

[0159] Beam Index First coefficient Second coefficient Third coefficient Fourth coefficient 1 1 0 1 0 2 0 1 0 1

[0160] Table 5

[0161] The bitmap corresponding to the third CSI-RS is: 10100101, or 10011001.

[0162] The values ​​of the coefficients for each beam after the fourth CSI-RS frequency domain compression are shown in Table 6:

[0163] Beam Index First coefficient Second coefficient Third coefficient Fourth coefficient 1 0 1 1 1 2 1 1 0 1

[0164] Table 6

[0165] The bitmap corresponding to the fourth CSI-RS is: 01111101, or 01111011.

[0166] The CSI feedback method provided in this application can be executed by a CSI feedback device. This application uses an example of a CSI feedback device executing the CSI feedback method to illustrate the CSI feedback device provided in this application.

[0167] like Figure 5 As shown in the illustration, this application embodiment also provides a Channel State Information (CSI) feedback device 500, comprising:

[0168] The first determining module 501 is used to determine the N Channel State Information Reference Signals (CSI-RS) to be measured; N is an integer greater than 1.

[0169] The second determining module 502 is used to measure the N CSI-RS to obtain CSI; wherein, the CSI includes: transmission rank, beam index corresponding to each of the P CSI-RS, and bit map corresponding to the P CSI-RS, the bit map being used to indicate the coefficients of the feedback beam of the CSI-RS after frequency domain compression; P is an integer less than or equal to N;

[0170] The sending module 503 is used to send the CSI to the network-side device.

[0171] As an optional embodiment, the first determining module includes:

[0172] The first receiving submodule is used to receive N CSI-RS configured by the network-side device;

[0173] or,

[0174] The second receiving submodule is used to receive M CSI-RS configured by the network-side device and to receive activation signaling; the activation signaling is used to activate N CSI-RS among the M CSI-RS; where M is an integer greater than N.

[0175] As an optional embodiment, the apparatus further includes:

[0176] The first configuration receiving module is used to receive the total number of beams that need to be fed back by the N CSI-RS configured by the network-side device, and determine the number of beams that each CSI-RS needs to feed back based on the total number of beams; or, the terminal receives the number of beams that each CSI-RS needs to feed back based on the network-side device.

[0177] The third determining module is used to determine the beam index corresponding to each of the P CSI-RS based on the number of beams that each CSI-RS needs to feed back.

[0178] As an optional embodiment, the apparatus further includes:

[0179] The second configuration receiving module is used to receive one or more values ​​of the subband precoding matrix indicator (PMI) configured by the network-side device.

[0180] The fourth determination module is used to perform frequency domain compression on the precoding matrices corresponding to the P CSI-RS based on one or more values ​​of the subband PMI, and to determine the coefficients of the feedback beams of the P CSI-RS after frequency domain compression.

[0181] As an optional embodiment, the bit map corresponding to the P CSI-RS includes: a bit map that maps the coefficients of the feedback beams of the P CSI-RS after frequency domain compression;

[0182] Alternatively, the bit map corresponding to the P CSI-RS includes: multiple bit maps, each bit map mapping the coefficients of the feedback beam of a CSI-RS after frequency domain compression;

[0183] The bit map corresponding to the P CSI-RS is determined by the terminal according to network configuration or pre-agreed upon.

[0184] As an optional embodiment, when P is less than N, the CSI further includes: the identification information of the P CSI-RS.

[0185] As an optional embodiment, the apparatus further includes:

[0186] The first mapping module is used to map the coefficients of the P CSI-RS feedback beams after frequency domain compression onto a bit map according to the network configuration or pre-agreed mapping rules.

[0187] or,

[0188] The second mapping module is used to map the coefficients of the feedback beam of each CSI-RS after frequency domain compression to the corresponding bit map according to the network configuration or pre-agreed mapping rules.

[0189] As an optional embodiment, the mapping rule includes at least one of the following:

[0190] Mapped onto the bitmap according to the CSI-RS priority order;

[0191] Mapped onto the bitmap according to the CSI-RS index size order;

[0192] Mapped onto the bit map according to the beam index size order corresponding to CSI-RS;

[0193] The coefficients of the CSI-RS feedback beam, after frequency domain compression, are mapped onto the bit map in the order of their identifiers.

[0194] Map the data onto the bitmap according to the size order of the transport layer identifiers corresponding to CSI-RS;

[0195] The data is mapped onto the bitmap according to the transport layer priority order corresponding to CSI-RS.

[0196] In this embodiment of the application, after a terminal measures multiple CSI-RS in a multi-point transmission system, it reports a CSI. The CSI carries a bit map corresponding to the CSI-RS determined by the terminal according to the network configuration or a pre-agreed mapping rule. The network-side device can determine the mapping relationship between the bit map in the CSI and the coefficients of the feedback beam of the CSI-RS after frequency domain compression according to the corresponding mapping rule, thereby achieving consistent understanding of the bit map between the terminal and the network-side device and improving the correct transmission efficiency of the CSI.

[0197] It should be noted that the Channel State Information (CSI) feedback device provided in this application embodiment is a device capable of executing the above-described Channel State Information (CSI) feedback method. Therefore, all embodiments of the above-described Channel State Information (CSI) feedback method are applicable to this device and can achieve the same or similar beneficial effects.

[0198] like Figure 6 As shown in the illustration, this application also provides a Channel State Information (CSI) feedback device 600, comprising:

[0199] The receiving module 601 is used to receive the CSI fed back by the terminal after measuring N CSI-RS. The CSI includes: transmission rank, beam index corresponding to each of the P CSI-RS, and bit map corresponding to the P CSI-RS. The bit map is used to indicate the coefficients of the feedback beam of the CSI-RS after frequency domain compression. N is an integer greater than 1. P is an integer less than or equal to N.

[0200] As an optional embodiment, the apparatus further includes:

[0201] The first configuration module is used to configure N CSI-RS for the terminal;

[0202] Alternatively, it can be used to configure M CSI-RS for a terminal and send activation signaling to the terminal; the activation signaling is used to indicate the activation of N CSI-RS among the M CSI-RS; where M is an integer greater than N.

[0203] As an optional embodiment, the apparatus further includes:

[0204] The second configuration module is used to configure the total number of N CSI-RS beams that need to be fed back to the terminal;

[0205] Alternatively, it can be used to configure the number of beams that each CSI-RS needs to feed back for the terminal.

[0206] As an optional embodiment, the apparatus further includes:

[0207] The third configuration module is used to configure one or more values ​​of the subband precoding matrix indicator (PMI) for the terminal.

[0208] As an optional embodiment, the apparatus further includes:

[0209] The fourth configuration module is used to configure the CSI fed back by the terminal, which includes one or more bitmaps.

[0210] Wherein, when the CSI includes a bit map, the bit map maps the frequency-domain compressed coefficients of the feedback beams of P CSI-RS; where the CSI includes multiple bit maps, each bit map maps the frequency-domain compressed coefficients of the feedback beams of one CSI-RS.

[0211] As an optional embodiment, when P is less than N, the CSI further includes: the identification information of the P CSI-RS.

[0212] As an optional embodiment, the apparatus further includes:

[0213] The tenth determining module is used to determine the mapping relationship between the bit map in the CSI and the coefficients of the feedback beam of the CSI-RS after frequency domain compression, according to the pre-agreed mapping rules.

[0214] As an optional embodiment, the mapping rule includes at least one of the following:

[0215] Mapped onto the bitmap according to the CSI-RS priority order;

[0216] Mapped onto the bitmap according to the CSI-RS index size order;

[0217] Mapped onto the bit map according to the beam index size order corresponding to CSI-RS;

[0218] The coefficients of the CSI-RS feedback beam, after frequency domain compression, are mapped onto the bit map in the order of their identifiers.

[0219] Map the data onto the bitmap according to the size order of the transport layer identifiers corresponding to CSI-RS;

[0220] The data is mapped onto the bitmap according to the transport layer priority order corresponding to CSI-RS.

[0221] In this embodiment of the application, after a terminal measures multiple CSI-RS in a multi-point transmission system, it reports a CSI. The CSI carries a bit map corresponding to the CSI-RS determined by the terminal according to the network configuration or a pre-agreed mapping rule. The network-side device can determine the mapping relationship between the bit map in the CSI and the coefficients of the feedback beam of the CSI-RS after frequency domain compression according to the corresponding mapping rule, thereby achieving consistent understanding of the bit map between the terminal and the network-side device and improving the correct transmission efficiency of the CSI.

[0222] It should be noted that the Channel State Information (CSI) feedback device provided in this application embodiment is a device capable of executing the above-described Channel State Information (CSI) feedback method. Therefore, all embodiments of the above-described Channel State Information (CSI) feedback method are applicable to this device and can achieve the same or similar beneficial effects.

[0223] The Channel State Information (CSI) feedback device in this embodiment can be an electronic device, such as an electronic device with an operating system, or a component in an electronic device, such as an integrated circuit or a chip. The electronic device can be a terminal, or other devices besides a terminal. For example, the terminal can include, but is not limited to, the type of terminal 11 listed above; other devices can be servers, network attached storage (NAS), etc., and this embodiment does not impose specific limitations.

[0224] The Channel State Information (CSI) feedback device provided in this application embodiment can achieve... Figures 1 to 4 The various processes implemented in the method embodiments achieve the same technical effect, and will not be described again here to avoid repetition.

[0225] Optional, such as Figure 7As shown, this application embodiment also provides a communication device 700, including a processor 701 and a memory 702. The memory 702 stores programs or instructions that can run on the processor 701. For example, when the communication device 700 is a terminal, the program or instructions executed by the processor 701 implement the various steps of the above-described Channel State Information (CSI) feedback method embodiment and achieve the same technical effect. When the communication device 700 is a network-side device, the program or instructions executed by the processor 701 implement the various steps of the above-described Channel State Information (CSI) feedback method embodiment and achieve the same technical effect. To avoid repetition, further details are omitted here.

[0226] This application embodiment also provides a terminal, including a processor and a communication interface, wherein the processor is used to determine N Channel State Information Reference Signals (CSI-RS) to be measured; N is an integer greater than 1; and to measure the N CSI-RS to obtain CSI; wherein the CSI includes: transmission rank, beam indices corresponding to P CSI-RS respectively, and a bit map corresponding to the P CSI-RS, the bit map being used to indicate the coefficients of the feedback beam of the CSI-RS after frequency domain compression; P is an integer less than or equal to N; the communication interface is used to send the CSI to a network-side device. This terminal embodiment corresponds to the above-described terminal-side method embodiment, and all implementation processes and methods of the above-described method embodiment can be applied to this terminal embodiment and can achieve the same technical effect. Specifically, Figure 8 A schematic diagram of the hardware structure of a terminal to implement an embodiment of this application.

[0227] The terminal 800 includes, but is not limited to, at least some of the following components: radio frequency unit 801, network module 802, audio output unit 803, input unit 804, sensor 805, display unit 806, user input unit 807, interface unit 808, memory 809, and processor 810.

[0228] Those skilled in the art will understand that the terminal 800 may also include a power supply (such as a battery) for supplying power to various components. The power supply may be logically connected to the processor 810 through a power management system, thereby enabling functions such as managing charging, discharging, and power consumption through the power management system. Figure 8 The terminal structure shown does not constitute a limitation on the terminal. The terminal may include more or fewer components than shown, or combine certain components, or have different component arrangements, which will not be elaborated here.

[0229] It should be understood that, in this embodiment, the input unit 804 may include a graphics processing unit (GPU) 8041 and a microphone 8042. The GPU 8041 processes image data of still images or videos obtained by an image capture device (such as a camera) in video capture mode or image capture mode. The display unit 806 may include a display panel 8061, which may be configured in the form of a liquid crystal display, an organic light-emitting diode, or the like. The user input unit 807 includes at least one of a touch panel 8071 and other input devices 8072. The touch panel 8071 is also called a touch screen. The touch panel 8071 may include a touch detection device and a touch controller. Other input devices 8072 may include, but are not limited to, physical keyboards, function keys (such as volume control buttons, power buttons, etc.), trackballs, mice, and joysticks, which will not be described in detail here.

[0230] In this embodiment, after receiving downlink data from the network-side device, the radio frequency unit 801 can transmit it to the processor 810 for processing; in addition, the radio frequency unit 801 can send uplink data to the network-side device. Typically, the radio frequency unit 801 includes, but is not limited to, antennas, amplifiers, transceivers, couplers, low-noise amplifiers, duplexers, etc.

[0231] The memory 809 can be used to store software programs or instructions, as well as various data. The memory 809 may primarily include a first storage area for storing programs or instructions and a second storage area for storing data. The first storage area may store the operating system, application programs or instructions required for at least one function (such as sound playback, image playback, etc.). Furthermore, the memory 809 may include volatile memory or non-volatile memory, or both. The non-volatile memory may be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory can be random access memory (RAM), static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct memory bus RAM (DRRAM). The memory 809 in the embodiments of this application includes, but is not limited to, these and any other suitable types of memory.

[0232] Processor 810 may include one or more processing units; optionally, processor 810 integrates an application processor and a modem processor, wherein the application processor mainly handles operations involving the operating system, user interface, and applications, and the modem processor mainly handles wireless communication signals, such as a baseband processor. It is understood that the aforementioned modem processor may also not be integrated into processor 810.

[0233] The processor 810 is configured to determine N Channel State Information Reference Signals (CSI-RS) to be measured, where N is an integer greater than 1; measure the N CSI-RS to obtain the CSI; wherein the CSI includes: transmission rank, beam indices corresponding to P CSI-RS respectively, and a bit map corresponding to the P CSI-RS, wherein the bit map is used to indicate the coefficients of the feedback beam of the CSI-RS after frequency domain compression; where P is an integer less than or equal to N;

[0234] Radio frequency unit 801 is used to send the CSI to network-side devices.

[0235] In this embodiment of the application, after a terminal measures multiple CSI-RS in a multi-point transmission system, it reports a CSI. The CSI carries a bit map corresponding to the CSI-RS determined by the terminal according to the network configuration or a pre-agreed mapping rule. The network-side device can determine the mapping relationship between the bit map in the CSI and the coefficients of the feedback beam of the CSI-RS after frequency domain compression according to the corresponding mapping rule, thereby achieving consistent understanding of the bit map between the terminal and the network-side device and improving the correct transmission efficiency of the CSI.

[0236] It should be noted that the terminal provided in this application embodiment is a terminal capable of executing the above-described Channel State Information (CSI) feedback method. Therefore, all embodiments of the above-described Channel State Information (CSI) feedback method are applicable to this terminal and can achieve the same or similar beneficial effects.

[0237] This application embodiment also provides a network-side device, including a processor and a communication interface. The communication interface is used to receive CSI feedback from a terminal after measuring N CSI-RS. The CSI includes: transmission rank, beam indices corresponding to each of the P CSI-RS, and a bitmap corresponding to each of the P CSI-RS. The bitmap indicates the coefficients of the feedback beam of the CSI-RS after frequency domain compression; N is an integer greater than 1; P is an integer less than or equal to N. This network-side device embodiment corresponds to the above-described network-side device method embodiment. All implementation processes and methods of the above method embodiments can be applied to this network-side device embodiment and achieve the same technical effects.

[0238] Specifically, embodiments of this application also provide a network-side device. For example... Figure 9 As shown, the network-side device 900 includes: an antenna 91, a radio frequency (RF) device 92, a baseband device 93, a processor 94, and a memory 95. The antenna 91 is connected to the RF device 92. In the uplink direction, the RF device 92 receives information through the antenna 91 and transmits the received information to the baseband device 93 for processing. In the downlink direction, the baseband device 93 processes the information to be transmitted and sends it to the RF device 92. The RF device 92 processes the received information and transmits it through the antenna 91.

[0239] The method executed by the network-side device in the above embodiments can be implemented in the baseband device 93, which includes a baseband processor.

[0240] Baseband device 93 may include, for example, at least one baseband board on which multiple chips are disposed, such as Figure 9As shown, one of the chips is, for example, a baseband processor, which is connected to the memory 95 via a bus interface to call the program in the memory 95 and execute the network device operations shown in the above method embodiment.

[0241] The network-side device may also include a network interface 96, such as a common public radio interface (CPRI).

[0242] Specifically, the network-side device 900 of this embodiment further includes: instructions or programs stored in a memory 95 and executable on a processor 94, wherein the processor 94 calls the instructions or programs in the memory 95 to execute. Figure 6 The methods executed by each module shown achieve the same technical effect, and to avoid repetition, they will not be described in detail here.

[0243] This application also provides a readable storage medium storing a program or instructions. When the program or instructions are executed by a processor, they implement the various processes of the above-described Channel State Information (CSI) feedback method embodiments and achieve the same technical effects. To avoid repetition, these will not be described again here.

[0244] The processor is the processor in the terminal described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.

[0245] This application embodiment also provides a chip, which includes a processor and a communication interface. The communication interface and the processor are coupled. The processor is used to run programs or instructions to implement the various processes of the above-described Channel State Information (CSI) feedback method embodiment, and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0246] It should be understood that the chip mentioned in the embodiments of this application may also be referred to as a system-on-a-chip, system chip, chip system, or system-on-a-chip, etc.

[0247] This application also provides a computer program / program product, which is stored in a storage medium and executed by at least one processor to implement the various processes of the above-described Channel State Information (CSI) feedback method embodiment, and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0248] This application also provides a communication system, including: a terminal and a network-side device, wherein the terminal can be used to perform the steps of the channel state information (CSI) feedback method as described above, and the network-side device can be used to perform the steps of the channel state information (CSI) feedback method as described above.

[0249] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0250] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a computer software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0251] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A Channel State Information (CSI) feedback method, characterized in that, include: The terminal determines the N Channel State Information Reference Signals (CSI-RS) to be measured; N is an integer greater than 1; The terminal measures the N CSI-RS to obtain the CSI; wherein, the CSI includes: transmission rank, beam index corresponding to each of the P CSI-RS, and bit map corresponding to the P CSI-RS, the bit map being used to indicate the coefficients of the feedback beam of the CSI-RS after frequency domain compression; P is an integer less than or equal to N; The terminal sends the CSI to the network-side device; Wherein, the N CSI-RS have the same number of ports, the P CSI-RS in the CSI have the same number of beams, or the last CSI-RS in the P CSI has a different number of beams than the other CSI-RS.

2. The method according to claim 1, characterized in that, The terminal determines N CSI-RS to be measured, including: The terminal receives N CSI-RS configured by the network-side equipment; or, The terminal receives M CSI-RS configured by the network-side device and receives activation signaling; the activation signaling is used to activate N CSI-RS among the M CSI-RS; where M is an integer greater than N.

3. The method according to claim 1 or 2, characterized in that, The method further includes: The terminal receives the number of beams that each CSI-RS configured on the network side device needs to feed back.

4. The method according to claim 1 or 2, characterized in that, The method further includes: The terminal receives one or more values ​​of the subband precoding matrix indicator (PMI) configured by the network-side device. The terminal performs frequency domain compression on the precoding matrices corresponding to the P CSI-RS according to one or more values ​​of the subband PMI, and determines the coefficients of the feedback beams of the P CSI-RS after frequency domain compression.

5. The method according to claim 1 or 2, characterized in that, The bit map corresponding to the P CSI-RS includes: a bit map that maps the coefficients of the feedback beams of the P CSI-RS after frequency domain compression; Alternatively, the bit map corresponding to the P CSI-RS includes: multiple bit maps, each bit map mapping the coefficients of the feedback beam of a CSI-RS after frequency domain compression; The bit map corresponding to the P CSI-RS is determined by the terminal according to network configuration or pre-agreed upon.

6. The method according to claim 1 or 2, characterized in that, When P is less than N, the CSI also includes the identification information of the P CSI-RS.

7. The method according to claim 4, characterized in that, The method further includes: According to the network configuration or pre-agreed mapping rules, the terminal maps the coefficients of the P CSI-RS feedback beams after frequency domain compression to a bit map; or, According to the network configuration or pre-agreed mapping rules, the terminal maps the coefficients of the feedback beam of each CSI-RS after frequency domain compression to the corresponding bit map.

8. The method according to claim 7, characterized in that, The mapping rule includes at least one of the following: Mapped onto the bitmap according to the CSI-RS priority order; Mapped onto the bitmap according to the CSI-RS index size order; Mapped onto the bit map according to the beam index size order corresponding to CSI-RS; The coefficients of the CSI-RS feedback beam, after frequency domain compression, are mapped onto the bit map in the order of their identifiers. Map the data onto the bitmap according to the size order of the transport layer identifiers corresponding to CSI-RS; The data is mapped onto the bitmap according to the transport layer priority order corresponding to CSI-RS.

9. A Channel State Information (CSI) feedback method, characterized in that, include: The network-side device receives the CSI fed back by the terminal after measuring N CSI-RS. The CSI includes: transmission rank, beam index corresponding to each of the P CSI-RS, and bit map corresponding to the P CSI-RS. The bit map is used to indicate the coefficients of the CSI-RS that need to be fed back after frequency domain compression; N is an integer greater than 1; P is an integer less than or equal to N. Wherein, the N CSI-RS have the same number of ports, the P CSI-RS in the CSI have the same number of beams, or the last CSI-RS in the P CSI has a different number of beams than the other CSI-RS.

10. The method according to claim 9, characterized in that, The method further includes: The network-side equipment configures N CSI-RS for the terminal; or, The network-side device configures M CSI-RS for the terminal and sends an activation signaling message to the terminal; the activation signaling message is used to indicate the activation of N CSI-RS among the M CSI-RS; where M is an integer greater than N.

11. The method according to claim 9 or 10, characterized in that, The method further includes: The network-side equipment configures the number of beams that each CSI-RS needs to feed back for the terminal.

12. The method according to claim 9 or 10, characterized in that, The method further includes: The network-side equipment configures one or more values ​​of the subband precoding matrix indicator PMI for the terminal.

13. The method according to claim 9 or 10, characterized in that, The method further includes: The network-side device configures the CSI fed back by the terminal to include one or more bitmaps; Wherein, when the CSI includes a bit map, the bit map maps the frequency-domain compressed coefficients of the feedback beams of P CSI-RS; where the CSI includes multiple bit maps, each bit map maps the frequency-domain compressed coefficients of the feedback beams of one CSI-RS.

14. The method according to claim 9 or 10, characterized in that, When P is less than N, the CSI also includes the identification information of the P CSI-RS.

15. The method according to claim 9 or 10, characterized in that, The method further includes: The network-side device determines the mapping relationship between the bit map in the CSI and the coefficients of the feedback beam of the CSI-RS after frequency domain compression, according to the pre-agreed mapping rules.

16. The method according to claim 15, characterized in that, The mapping rule includes at least one of the following: Mapped onto the bitmap according to the CSI-RS priority order; Mapped onto the bitmap according to the CSI-RS index size order; Mapped onto the bit map according to the beam index size order corresponding to CSI-RS; The coefficients of the CSI-RS feedback beam, after frequency domain compression, are mapped onto the bit map in the order of their identifiers. Map the data onto the bitmap according to the size order of the transport layer identifiers corresponding to CSI-RS; The data is mapped onto the bitmap according to the transport layer priority order corresponding to CSI-RS.

17. A Channel State Information (CSI) feedback device, characterized in that, include: The first determining module is used to determine the N Channel State Information Reference Signals (CSI-RS) to be measured; N is an integer greater than 1; The second determining module is used to measure the N CSI-RS to obtain the CSI; wherein the CSI includes: transmission rank, beam index corresponding to each of the P CSI-RS, and bit map corresponding to the P CSI-RS, the bit map being used to indicate the coefficients of the feedback beam of the CSI-RS after frequency domain compression; P is an integer less than or equal to N; The sending module is used to send the CSI to the network-side device; Wherein, the N CSI-RS have the same number of ports, the P CSI-RS in the CSI have the same number of beams, or the last CSI-RS in the P CSI has a different number of beams than the other CSI-RS.

18. A terminal, characterized in that, It includes a processor and a memory, the memory storing a program or instructions that can run on the processor, the program or instructions being executed by the processor to implement the steps of the Channel State Information (CSI) feedback method as described in any one of claims 1 to 8.

19. A Channel State Information (CSI) feedback device, characterized in that, include: The receiving module is used to receive the CSI fed back by the terminal after measuring N CSI-RS. The CSI includes: transmission rank, beam index corresponding to each of the P CSI-RS, and bit map corresponding to the P CSI-RS. The bit map is used to indicate the coefficients of the CSI-RS that need to be fed back after frequency domain compression; N is an integer greater than 1; P is an integer less than or equal to N. Wherein, the N CSI-RS have the same number of ports, the P CSI-RS in the CSI have the same number of beams, or the last CSI-RS in the P CSI has a different number of beams than the other CSI-RS.

20. A network-side device, characterized in that, It includes a processor and a memory, the memory storing a program or instructions that can run on the processor, the program or instructions being executed by the processor to implement the steps of the Channel State Information (CSI) feedback method as described in any one of claims 9 to 16.

21. A readable storage medium, characterized in that, The readable storage medium stores a program or instructions that, when executed by a processor, implement the Channel State Information (CSI) feedback method as described in any one of claims 1-8, or implement the steps of the Channel State Information (CSI) feedback method as described in any one of claims 9 to 16.

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