CSI reporting for multi-TRP transmission / panel

Abstract

Embodiments of the present disclosure relate to methods, devices, and apparatus for channel state information (CSI) reporting for multiple reception point (TRP) transmissions. In an embodiment of the present disclosure, a method may include sending a first CSI report about a first TRP among multiple TRPs of a serving terminal device for a channel state information reference signal (CSI-RS) resource set used for CSI acquisition. The method may also include sending a second CSI report about a second TRP among multiple TRPs of a serving terminal device for the CSI-RS resource set. Using the embodiments of the present disclosure, CSI reporting for multiple TRP transmissions can be supported.

Description

Technical Field

[0001] Non-limiting and exemplary embodiments of the present disclosure relate generally to the field of wireless communication technology, and more specifically to methods, devices and apparatus for sending channel state information (CSI) reports for multiple transmission reception point (TRP) transmissions and receiving CSI reports for multiple TRP transmissions. Background Art

[0002] The New Radio Access System (also known as the NR system or NR network) is the next generation communication system. In the Radio Access Network (RAN) #71 meeting of the 3rd Generation Partnership Project (3GPP) working group, research on the NR system was approved. The NR system will consider the frequency range up to 100Ghz, and its goal is that a single technical framework addresses all usage scenarios, requirements and deployment scenarios defined in the technical report TR 38.913, which includes requirements such as enhanced mobile broadband, massive machine type communications, and ultra-reliable low-latency communications.

[0003] Since May 2016, discussions on multi-antenna technology for NR have begun, involving several aspects, including multi-antenna schemes, beam management, channel state information (CSI) acquisition, and reference signals and quasi co-location (QCL). Both single TRP transmission and multi-TRP transmission are agreed upon in the NR system.

[0004] Regarding the codeword (CW) to layer mapping in NR, it has been agreed that:

[0005] NR supports the following number of CWs per PDSCH / PUSCH allocation per UE:

[0006] - For layer 1 to 4 transmission: 1 CW

[0007] - For 5 to 8 layer transmission: 2 CW

[0008] ·Confirm the following working assumptions as an agreement:

[0009] - For layer 3 and layer 4 transmission, NR supports 1 CW per UE per physical downlink shared channel (PDSCH) / physical uplink shared channel (PUSCH) allocation

[0010] - For further study (FFS): Support for mapping 2-CW to 3 layers and 2-CW to 4 layers

[0011] DMRS port groups belonging to one CW can have different QCL assumptions

[0012] • One uplink (UL) or downlink (DL) related downlink control indication (DCI) includes a modulation and coding scheme (MCS) for each CW.

[0013] For each CW a channel quality indicator (CQI) is calculated

[0014] Regarding CSI reporting in NR, it was also agreed to add the following:

[0015] "When the UE is configured with the higher layer parameter ReportQuantity set to "CSI-RS Resource Indication (CRI) / Rank Indication (RI) / Precoding Matrix Indicator (PMI) / Channel Quality Indicator (CQI)", "CRI / RI / i1", "CRI / RI / i1 / CQI", "CRI / RI / CQI" or "CRI / RI / Layer Indicator (LI) / PMI / CQI", and the corresponding resource set for channel measurement is configured with multiple resources, the UE shall derive CSI parameters other than CRI conditioned on the reported CRI."

[0016] With respect to single PDSCH and multiple PDSCHs from separate TRPs, it is further agreed that:

[0017] For NR reception, take the following actions:

[0018] - A single NR-PDCCH schedules a single NR-PDSCH, where separate layers are sent from separate TRPs

[0019] - Multiple NR-PDCCHs, each NR-PDCCH scheduling a corresponding NR-PDSCH, where each NR-PDSCH is sent from a separate TRP

[0020] - NOTE: The case where a single NR-PDCCH schedules a single NR-PDSCH can be done in a spec-transparent manner, where each layer is sent jointly from all TRPs

[0021] -Note: The CSI feedback details for the above situations can be discussed separately

[0022] The priority of multi-TRP / panel transmission is reduced and therefore not discussed in detail in Release 15. Therefore, the current NR, CSI-RS configuration and TCI state configuration are based on a single TRP / panel. For multi-TRP transmission, the TRP is not QCLed, and therefore, the solution for CSI measurement and reporting of single TRP transmission cannot be applied to multi-TRP transmission. Summary of the invention

[0023] To this end, in the present disclosure, a new solution for CSI reporting for multi-TRP transmission is provided to alleviate or at least mitigate at least some of the problems in the prior art. It should be understood that the ideas disclosed herein can also be used for multi-panel transmission, where a panel is a group of antennas.

[0024] According to a first aspect of the present disclosure, a method for sending a CSI report for multiple TRP transmission is provided. The method may include: sending a first CSI report about a first TRP among multiple TRPs of a serving terminal device for a channel state information reference signal (CSI-RS) resource set for CSI acquisition; and sending a second CSI report about a second TRP among multiple TRPs of a serving terminal device for the CSI-RS resource set.

[0025] According to a second aspect of the present disclosure, a method for receiving a CSI report for a multi-TRP transmission is provided. The method may include: for a channel state information reference signal (CSI-RS) resource set for CSI acquisition, receiving a first CSI report about a first TRP in a plurality of TRPs of a serving terminal device, and for a CSI-RS resource set, receiving a second CSI report about a second TRP in a plurality of TRPs of a serving terminal device.

[0026] According to a third aspect of the present disclosure, a terminal device is provided, wherein the terminal device is configured to send a CSI report for a multi-TRP transmission. The terminal device may include a transceiver and a processor, the processor being configured to control the transceiver to: send a first CSI report on a first TRP among multiple TRPs serving the terminal device for a channel state information reference signal (CSI-RS) resource set for CSI acquisition; and send a second CSI report on a second TRP among multiple TRPs serving the terminal device for a CSI-RS resource.

[0027] According to a fourth aspect of the present disclosure, a network device is provided, wherein the network device is configured to receive a CSI report for a multi-TRP transmission. The network device may include a transceiver and a processor, wherein the processor is configured to control the transceiver: for a channel state information reference signal (CSI-RS) resource set for CSI acquisition, receive a first CSI report on a first TRP among multiple TRPs of a serving terminal device; and for the CSI-RS resource set, receive a second CSI report on a second TRP among multiple TRPs of the serving terminal device.

[0028] According to a fifth aspect of the present disclosure, a terminal device is provided. The terminal device may include a processor and a memory. The memory may be coupled to the processor and have a program code therein, which, when executed on the processor, causes the terminal device to perform operations according to the method of any embodiment of the first aspect.

[0029] According to a sixth aspect of the present disclosure, a network device is provided. The network device may include a processor and a memory. The memory may be coupled to the processor and have a program code therein, which, when executed on the processor, causes the network device to perform operations according to the method of any embodiment of the second aspect.

[0030] According to a seventh aspect of the present disclosure, there is provided a computer-readable storage medium having computer program code embodied thereon, the computer program code being configured to, when executed, cause an apparatus to perform the actions of the method according to any embodiment of the first aspect.

[0031] According to an eighth aspect of the present disclosure, there is provided a computer-readable storage medium having computer program code implemented thereon, the computer program code being configured to, when executed, cause an apparatus to perform the actions of the method according to any embodiment of the second aspect.

[0032] According to a ninth aspect of the present disclosure, a computer program product is provided, the computer program product comprising the computer-readable storage medium according to the seventh aspect.

[0033] According to a tenth aspect of the present disclosure, there is provided a computer program product, comprising the computer-readable storage medium according to the eighth aspect.

[0034] By using the embodiments of the present disclosure, CSI reporting for multi-TRP transmission can be supported. In some embodiments, the signaling overhead of CSI reporting can also be reduced.

[0035] It should be understood that the invention summary is not intended to identify the key or essential features of the embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The above and other features of the present disclosure will become more apparent by describing in detail embodiments shown in the embodiments with reference to the accompanying drawings, in which like reference numerals represent the same or similar components throughout the drawings, and in which:

[0037] Figure 1 An example scenario in which multi-TRP transmission of the present disclosure may be implemented is shown;

[0038] Figure 2A flow chart of a method for sending a CSI report for a multi-TRP transmission at a terminal device according to some embodiments of the present disclosure is shown;

[0039] Figure 3 shows possible combinations of the number of layers for a multi-TRP transmission involving two TRPs according to some embodiments of the present disclosure;

[0040] Figure 4 shows an example combination of the number of layers for a multi-TRP transmission involving two TRPs according to some embodiments of the present disclosure;

[0041] Figure 5 shows an example combination of the number of layers for a multi-TRP transmission involving two TRPs according to some embodiments of the present disclosure;

[0042] Figure 6 A flow chart of a method for receiving a CSI report for a multi-TRP transmission at a network device according to some embodiments of the present disclosure is shown;

[0043] Figure 7 A block diagram schematically illustrates an apparatus for sending a CSI report at a terminal device according to some embodiments of the present disclosure;

[0044] Figure 8 A block diagram schematically illustrates an apparatus for receiving a CSI report at a network device according to some embodiments of the present disclosure; and

[0045] Fig. 9 A simplified block diagram of an apparatus 910 as described herein that may be implemented as or included in a terminal device such as a UE and an apparatus 920 that may be implemented as or included in a network device such as a gNB is schematically shown. DETAILED DESCRIPTION

[0046] Hereinafter, the solutions provided in the present disclosure will be described in detail by way of embodiments with reference to the accompanying drawings. It should be understood that these embodiments are only provided to enable those skilled in the art to better understand and implement the present disclosure, and are not intended to limit the scope of the present disclosure in any way.

[0047] In the accompanying drawings, various embodiments of the present disclosure are shown with block diagrams, flow charts and other figures. Each frame in the flow chart or frame can represent a module, a program or a code portion containing one or more executable instructions for performing a specified logical function, and in the present disclosure, unnecessary frames are shown with dotted lines. In addition, although these frames are shown with a specific sequence of steps for performing the method, in fact, they do not necessarily have to be performed strictly in accordance with the sequence shown. For example, they can be performed in reverse sequence or simultaneously, depending on the nature of the corresponding operation. It should also be noted that each frame and combination thereof in the block diagram and / or flow chart can be implemented by a dedicated hardware-based system for performing a specified function / operation, or can be implemented by a combination of dedicated hardware and computer instructions.

[0048] In general, unless expressly defined otherwise herein, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field. Unless expressly stated otherwise, all references to "a / an / the / said [element, device, component, part, step, etc.]" should be openly interpreted as referring to at least one instance of the element, device, component, part, unit, step, etc., without excluding a plurality of such devices, components, parts, units, steps, etc. In addition, the indefinite article "a / an" used herein does not exclude a plurality of such steps, units, modules, devices, objects, etc.

[0049] In addition, in the context of the present disclosure, a user equipment (UE) may refer to a terminal, a mobile terminal (MT), a subscriber station, a portable subscriber station, a mobile station (MS) or an access terminal (AT), and some or all functions of a UE, a terminal, a MT, a SS, a portable subscriber station, a MS or an AT may be included. In addition, in the context of the present disclosure, the term "BS" may refer to, for example, a Node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), a gNB (next generation Node B), a radio head (RH), a remote radio head (RRH), a relay, or a low power node (such as a femto node, a micro node, etc.).

[0050] As described in the background art, in Release 15 of the NR system, CSI-RS configuration and TCI state configuration are based on a single TRP / panel. In NR, it is agreed in CSI reporting that the same sequence is used for a PDSCH in DL DMRS design. Specifically, when a UE is configured with a CSI-ReportConfig having a higher layer parameter ReportQuantity set to "cri-RSRP", "cri-RI-PMI-CQI", "cir-RI-i1", "cir-RI-i1-CQI", "cir-RI-CQI", or "cri-RI-LI-PMI-CQI", and the corresponding resource set for channel measurement is configured with Ks > 1 resources, the UE shall derive CSI parameters other than the CRI conditioned on the reported CRI, where CRI k (k >= 0) corresponds to the configured (k + 1)-th entry of the associated nzp-CSI-Resource for channel measurement in the corresponding nzp-CSI-RS-ResourceSet, and the (k + 1)-th entry of the associated csi-IM-Resource in the corresponding csi-IM-ResourceSet (if configured). If Ks = 2 CSI-RS resources are configured, each resource shall contain up to 16 CSI-RS ports. If 2 < Ks <= 8 CSI-RS resources are configured, each resource shall contain at most CSI_RS ports.

[0051] For illustrative purposes, Table 1 shows the CSI reporting structure in the NR system.

[0052] Table 1 CSI reporting structure in the NR system

[0053]

[0054] For multi-TRP transmission, the TRPs do not perform QCL, and thus, the solution for CSI measurement and reporting for single-TRP transmission cannot be applied to multi-TRP / panel transmission.

[0055] Embodiments of the present disclosure provide a solution for CSI reporting. The basic idea is that the terminal device sends multiple CSI reports for the CSI-RS resource set used for CSI acquisition. With multiple CSI reports, multi-TRP / panel transmission can be enabled for the terminal device. In addition, an offset value indication is also proposed to reduce CSI signaling overhead.

[0056] In some embodiments of the present disclosure, a terminal device sends a first CSI report about a first TRP among multiple TRPs serving a terminal device for a CSI-RS resource set used for CSI acquisition; and sends a second CSI report about a second TRP among multiple TRPs serving a terminal device for a CSI-RS resource set. The network device receives the first CSI report about the first TRP and the second CSI report about the second TRP, and obtains CSI information from the two reports. It should be understood that the basic idea disclosed herein can also be used for multi-panel transmission, where a panel represents a group of antennas on a network device and / or a user terminal device, and multi-panel transmission represents transmission using multiple panels for a single user device. When this basic idea is used for multi-panel transmission, CSI measurements and CSI reports will be performed for the corresponding panels rather than for the TRPs of multi-TRP transmissions.

[0057] In the following, reference will be made to Figures 2 to 9 The solution proposed in the present disclosure is described in detail by taking multi-TRP transmission as an example. However, it should be understood that the following embodiments are given for illustrative purposes only, and the present disclosure is not limited thereto. In particular, as long as it is feasible from a technical point of view, the different embodiments described herein may be implemented individually, separately or in combination in any suitable manner.

[0058] Figure 2 The flowchart of a method for sending a CSI report for multi-TRP transmission at a terminal device according to some embodiments of the present disclosure is schematically shown. The method 200 may be performed at a terminal device (eg, a terminal device such as a UE or other similar device).

[0059] like Figure 2 As shown, in step 210, the terminal device sends a first CSI report on a first TRP among multiple TRPs serving the terminal device for a CSI-RS resource set used for CSI acquisition.

[0060] The CSI report may be configured by the network device. For example, the CSI report may be sent periodically, or semi-permanently, or alternatively, the CSI report may be sent after receiving a report request from the network device. When it is time to report the CSI or after receiving a report request, the terminal device may select CSI-RS resources from one CSI-RS resource set for each TRP involved in the multi-TRP transmission. The terminal device then performs CSI measurements using the CSI-RS resources selected for each TRP to obtain CSI information for each TRP. For one CSI-RS resource set used for CSI acquisition, the terminal device may send multiple sets of CSI reports for multiple TRPs, for example, one report for each TRP.

[0061] Therefore, the terminal device may send a first CSI report about the first TRP to the network device. The first CSI report may include a CSI-RS resource indication (CRI) and a rank indication (RI) of the first TRP. The CRI indicates the CSI-RS resources used by the terminal device for CSI acquisition or measurement. The RI indicates the maximum number of layers supported by the terminal device. In some embodiments of the present disclosure, the CSI report may also include any of a precoding matrix indicator (PMI) of the first TRP; a channel quality indicator (CQI) and a layer indication (LI), etc. The PMI indicates the index of the precoding matrix, the CQI indicates the channel quality, and the LI indicates the layer with the best channel quality.

[0062] In step 220, the terminal device sends a second CSI report on a second TRP among multiple TRPs serving the terminal device for the CSI-RS resource set.

[0063] Similar to the first CSI report, the second CSI report may include the CRI and rank indication RI of the second TRP. In some embodiments of the present disclosure, the CSI report may also include any of the PMI, CQI, layer indication, etc. of the second TRP.

[0064] In some embodiments of the present disclosure, the first CSI report may include an RI value indicating the absolute RI of the first TRP, and the second CSI report may use an offset value relative to the RI value of the first TRP to indicate the RI value of the second TRP. In this way, the signaling overhead of the CSI report can be reduced.

[0065] For the purpose of illustration, the embodiment of the offset indication regarding RI will be described by taking dual TRP transmission as an example.

[0066] Figure 3 1 shows possible combinations of the number of layers of dual TRP transmission involving two TRPs according to some embodiments of the present disclosure. According to the current protocol, the NR system supports up to 8 layers of transmission, and thus the combination of the number of layers of dual TRP transmission may include layers 1 to 8 of TRP 1 combined with layers 0 to 8 of TRP 2, where layer 0 indicates that TRP 2 is not involved in the transmission. Therefore, it is possible to obtain Figure 3 Possible combinations shown.

[0067] However, according to the current protocol, the total number of layers should not be greater than 8, and the number of codewords should not be greater than 2. Therefore, the communication indicated by reference numeral 310 cannot be used. In addition, certain combinations can be further excluded by further limiting the difference between the number of layers of the two TRPs. In multi-TRP transmission, the two TRPs can have substantially similar spatial multiplexing capabilities, so the layer difference between the two TRPs can be limited to one layer. Therefore, the combination indicated by reference numerals 320A and 320B cannot be used either.

[0068] After eliminating these unavailable combinations, we can obtain Figure 4 It should be noted that Figure 4 The combinations shown are for illustrative purposes only, and the present disclosure is not limited thereto. In some embodiments, only combination 310 may be excluded, and combinations 320A and 320B may still be included in the final combination. For illustrative purposes, reference will be made to Figure 4 The combinations shown are used to describe embodiments of the present disclosure.

[0069] In some embodiments of the present disclosure, the number of bits used for CSI reporting may depend on at least one of the following parameters: the number of ports used for each CSI-RS resource (e.g., denoted as P), the number of allowed RI values ​​configured in the codebook subset restriction (CBSR) (e.g., denoted as n), and the number of bits used for CSI reporting. RI ), and the number of CSI-RS resources in a CSI-RS resource set (e.g., expressed as N).

[0070] For CSI reporting, one of the two CSI reports may contain the absolute value of the RI. The RI value may be subject to codebook subset restrictions (CBSR). For the other of the two CSI reports, the RI may be indicated by an offset value relative to the RI value of the first TRP. Figure 4 For the combinations shown, 2 bits may be used to indicate the offset value.

[0071] Table 2 Example table of RI offset

[0072] RI offset value 00 -1 01 0 10 1 11 Reserve or indicate that the RI of this CRI is 0

[0073] In Table 2, the offset may indicate a positive value, a negative value, or zero. In other words, the offset may indicate that the RI value is higher, lower, or equal to the absolute value of the reported rank indication. "00", "01", "10" may be used to indicate combinations other than those in the first row, and "11" may be used to indicate a combination in which one of the RIs in the first row is 0. When RI is expressed in absolute value, a maximum of 3 bits are required to indicate layers 0 to 4 or layers 1 to 8; with the help of the offset value, only 2 bits are required to indicate the same RI range. Therefore, the signaling overhead of the CSI report can be reduced.

[0074] In some embodiments of the present disclosure, one of the two TRPs may be dynamically selected, for which the CSI includes an absolute value of the RI, and in this case; a TRP having a larger or lower rank indication value may be selected as the TRP having the RI indicated by the absolute value. Therefore, the offset value may indicate a non-positive value or a non-negative value. In this way, more combinations may be supported or the signaling overhead may be further reduced.

[0075] Table 3 shows another example table of RI offsets according to some embodiments of the present disclosure.

[0076] Table 3 Example table of RI offset

[0077]

[0078]

[0079] With the help of this table, "00", "01" can be used to indicate combinations other than the combination in the first row, and "11" can be used, for example, to indicate a combination in the first row where one of the RIs is 0. In addition, a larger RI difference range can also be indicated, which means that all or part of the excluded combinations 320A and 320B can be included in the final combination.

[0080] In some embodiments of the present disclosure, one TRP with a larger rank indication value may be selected as the TRP with an RI indicated by an absolute value. This is feasible because the CRI may indicate the index of the CSI-RS. In this way, the offset value may indicate a non-positive value. In other words, the offset value indicates that the rank indication value is lower than or equal to the absolute value of the reported rank indication. For example, if the RI of TRP 1 is 2 and the RI of TRP 2 is 3, an RI with an absolute value of 3 will be reported for TRP 2, and an offset value of "1" will be reported for TRP1. The RI value of TRP 1 may be determined to be 2 (=3-1) based on the reported absolute value and offset value. As another example, if the RI of TRP 1 is 2 and the RI of TRP 2 is 1, an RI with an absolute value of 2 will be reported for TRP 1, and an offset value of "1" will be reported for TRP 2. The RI value of TRP 2 may be determined to be 1 (=2-1) based on the reported absolute value and offset value.

[0081] In some embodiments of the present disclosure, a TRP with a lower rank indication value may be selected as the TRP with the RI indicated by the absolute value. In this way, the offset value may indicate a non-negative value. In other words, the offset value indicates that the rank indication value is greater than or equal to the absolute value of the reported rank indication. In this case, the RI value with the reported offset value may be determined as the sum of the reported absolute value and the offset value.

[0082] Table 4 shows another example table of RI offset according to some embodiments of the present disclosure, where only one bit is used.

[0083] Table 4 Example table of RI offset

[0084] RI offset value 00 0 01 1

[0085] With the help of this table, "0", "1" can be used to indicate combinations other than those in the first row. Figure 5 Combinations where one of the RIs is 0 in the highlighted first row, allow for different solutions.

[0086] In some embodiments of the present disclosure, the reported value of RI in two CSI reports may be a combined value. For example, for two CSI reports, RI is reported using one field, and the value of the field may indicate a combination of two RI values ​​(first RI, second RI). In addition, the allowed number of combinations of the first RI and the second RI may be different based on different values ​​of parameters from at least one of the following: the number of ports for each CSI-RS resource (e.g., represented as P), the number of allowed RI values ​​configured in the codebook subset restriction (CBSR) (e.g., represented as nRI), and the number of CSI-RS resources in a CSI-RS resource set (e.g., represented as N). In some embodiments, a report with a larger rank indication value may be selected as the first value in the reported RI combination. In this case, the first value in the reported RI combination may not be less than the second value in the reported RI combination, that is, in the RI combination (first RI, second RI), the first RI>=second RI, and thus further overhead reduction may be achieved. In some embodiments, a report with a lower rank indication value may be selected as the first value in the reported RI combination. In this case, the first value in the reported RI combination may not be greater than the second value, that is, in the RI combination (first RI, second RI), the first RI<=second RI, so further overhead reduction can be achieved.

[0087] In some embodiments of the present disclosure, if the RI value is 0, this means that there is no RI report for the TRP, which can be indicated by other parameters, and no offset value is required to indicate the RI value "0". For example, only one set of CSI with non-zero RI values ​​can be reported. One or more bits can be used to indicate whether one CSI report or multiple CSI reports are reported. For example, if only one CSI report is indicated, the total number of layers reported from the UE is the RI value in the reported CSI report. If two CSI reports are indicated, the total number of layers reported from the UE is the sum of the two actual RI values ​​contained in the two CSI reports, respectively. In addition, when multiple CSI reports are reported, the value of RI can be limited to no more than 4 in one set. Alternatively, if one of the two RI values ​​is 0, two CSI reports with the same CSI information can also be reported. For example, when the values ​​of the two CRI reports and / or the RI values ​​in the two CSI reports are the same, in fact, only one CSI is valid. In this case, the total number of layers reported from the UE is the RI value in only one CSI report in the first CSI report or the second CSI report. If the CRI values ​​in the two CSI reports are different, then both CSI reports are valid and the total number of layers reported from the UE may be determined as the sum of the two actual RI values.

[0088] In one embodiment, if the number of ports for each CSI-RS resource in the CSI-RS resource set is P=1, the number of bits reported by the CRI in each CSI report is ceil(log2(N)) and the number of bits reported by the RI in each CSI report is 0. If the two values ​​of CRI in two CSI reports are the same, the total number of RIs reported from the UE is 1; if the two values ​​of CRI in two CSI reports are different, the total number of RIs reported from the UE is 2.

[0089] In another embodiment, if the number of ports for each CSI-RS resource in the CSI-RS resource set is P=2, the number of bits reported by the CRI in each CSI report is ceil(log2(N) and the number of bits reported by the RI in the first CSI report is min(1, ceil(log2(n RI )). For example, if the number of allowed RI values ​​n RI =1, the number of bits reported by RI in each CSI report is 0. For another example, if the number of allowed RI values ​​n RI =2, then the reported RI value in each CSI report can be an absolute RI value from {1, 2}, and the number of bits reported in each CSI report is 1. For another example, if the number of allowed RI values ​​n RI=2, the reported value of RI in the first CSI report may be an absolute value from {1, 2}, the number of bits reported in the RI in the first CSI report is 1, the reported value of RI in the second CSI report may be an offset value shown in Table 2, Table 3 or Table 4, and the number of bits reported in the RI in the second CSI report may be 2, 2 or 1 for Table 2, Table 3 or Table 4, respectively. For another example, if the number of allowed RI values ​​n RI =2, then the reported RI values ​​of the two CSI reports can be at least one of {(1,1), (1,2), (2,1), (2,2)}, and the number of bits of the RI combined report is 2. For another example, if the number of allowed RI values ​​n RI =2, the reported RI values ​​of the two CSI reports can be from at least one of {(1,1), (1,2), (2,2)}, or can be from at least one of {(1,1), (2,1), (2,2)}, and the number of bits of the RI combined report is 2.

[0090] In one embodiment, if the number of ports for each CSI-RS resource in a CSI-RS resource set is P=4, then the number of bits reported by the CRI in each CSI report is ceil(log2(N)). For example, if the number of allowed RI values ​​n RI =1, the number of bits reported by RI in each CSI report is 0. For another example, if the number of allowed RI values ​​n RI =2, then the reported RI value in each CSI report can be an absolute RI value of two values ​​from {1, 2, 3, 4}, and the number of bits reported in each CSI report is 1. For another example, if the number of allowed RI values ​​n RI =3 or 4, the reported RI value in each CSI report can be an absolute RI value of 3 values ​​or 4 values ​​from {1, 2, 3, 4}, and the number of bits of the RI report in each CSI report is 2. For another example, if the number of allowed RI values ​​n RI =2, the reported value of RI in the first CSI report may be the absolute value of two values ​​from {1, 2, 3, 4}, the number of bits reported in the RI in the first CSI report may be 1, the reported value of RI in the second CSI report may be the offset value shown in Table 2, Table 3 or Table 4, and the number of bits reported in the RI in the second CSI report may be 2, 2 or 1 for Table 2, Table 3 or Table 4, respectively. For another example, if the number of allowed RI values ​​n RI=3 or 4, the reported value of RI in the first CSI report may be the absolute value of three or four values ​​from {1, 2, 3, 4}, and the number of bits reported by RI in the first CSI report may be 2, and the reported value of RI in the second CSI report may be the offset value shown in Table 2, Table 3 or Table 4, and the number of bits reported by RI in the second CSI report may be 2, 2 or 1 for Table 2, Table 3 or Table 4, respectively. For another example, the reported values ​​of RI in two CSI reports may be combined values, and the reported values ​​of the RI combination of the two CSI reports may come from at least one of {(1,1), (1,2), (1,3), (1,4), (2,1), (2,2), (2,3), (2,4), (3,1), (3,2), (3,3), (3,4), (4,1), (4,2), (4,3), (4,4)}, or may come from at least one of {(1,1), (1,2), (2,1), (2,2), (2,3), (3,2), (3,3), (3,4), (4,3), (4,4)}, and the number of bits of the RI combination report is 4. For another example, the reported values ​​of RI in two CSI reports may be combined values, and the reported values ​​of the RI combination of the two CSI reports may come from at least one of {(1, 1), (1, 2), (1, 3), (1, 4), (2, 1), (2, 2), (2, 3), (2, 4), (3, 3), (3, 4), (4, 4)}, or may come from at least one of {(1, 1), (2, 1), (2, 2), (3, 1), (3, 2), (3, 3), (4, 1), (4, 2), (4, 3), (4, 4)}, and the number of bits of the RI combination report is 4. For another example, the reported RI values ​​in the two CSI reports may be combined values, and the reported RI combination values ​​of the two CSI reports may be from at least one of {(1, 1), (1, 2), (2, 2), (2, 3), (3, 3), (3, 4), (4, 4)}, or may be from at least one of {(1, 1), (2, 1), (2, 2), (3, 2), (3, 3), (4, 3), (4, 4)}, and the number of bits of the RI combination report is 3. In addition, based on the number of allowed RI values, combinations with restricted RI values ​​may be excluded, and the number of bits of the RI combination report may be further reduced.

[0091] In one embodiment, if the number of ports for each CSI-RS resource in a CSI-RS resource set is P>4, for example, P may be 8, 12, 16, 24, or 32. The number of CRI bits in each CSI report is ceil(log2(N)). For example, if the number of allowed RI values ​​n RI=1, the number of bits reported by RI in each CSI report is 0. For another example, if the number of allowed RI values ​​n RI =2, then the reported RI value in each CSI report can be an absolute RI value of two values ​​from {1, 2, 3, 4, 5, 6, 7, 8}, and the number of bits reported in each CSI report is 1. For another example, if the number of allowed RI values ​​n RI =3 or 4, the reported RI value in each CSI report can be an absolute RI value of 3 or 4 values ​​from {1, 2, 3, 4, 5, 6, 7, 8}, and the number of bits of the RI report in each CSI report is 2. For another example, if the number of allowed RI values ​​n RI =5 or 6 or 7 or 8, the reported RI value in each CSI report can be an absolute RI value of 5 values, 6 values, 7 values ​​or 8 values ​​from {1, 2, 3, 4, 5, 6, 7, 8}, and the number of bits of the RI report in each CSI report is 3. For another example, if the number of allowed RI values ​​n RI =2, the reported value of RI in the first CSI report may be the absolute value of two values ​​from {1, 2, 3, 4, 5, 6, 7, 8}, and the number of bits reported in the RI in the first CSI report may be 1; and the reported value of RI in the second CSI report may be the offset value shown in Table 2, Table 3, or Table 4, and the number of bits reported in the RI in the second CSI report may be 2, 2, or 1 for Table 2, Table 3, or Table 4, respectively. For another example, if the number of allowed RI values ​​n RI =3 or 4, the reported value of RI in the first CSI report may be the absolute value of three or four values ​​from {1, 2, 3, 4, 5, 6, 7, 8}, and the number of bits of the RI report in the first CSI report may be 2, and the reported value of RI in the second CSI report may be the offset value shown in Table 2, Table 3, or Table 4, and the number of bits of the RI report in the second CSI report may be 2, 2, or 1 for Table 2, Table 3, or Table 4, respectively. For another example, if the number of allowed RI values ​​n RI=5 or 6 or 7 or 8, the reported value of RI in the first CSI report can be the absolute value of 5 values ​​or 6 values ​​or 7 values ​​or 8 values ​​from {1, 2, 3, 4, 5, 6, 7, 8}, and the number of bits of the RI report in the first CSI report can be 3, and the reported value of RI in the second CSI report can be the offset value shown in Table 2, Table 3 or Table 4, and the number of bits of the RI report in the second CSI report can be 2, 2 or 1 for Table 2, Table 3 or Table 4, respectively. For another example, the reported values ​​of RI in two CSI reports may be combined values, and the reported values ​​of the RI combination of the two CSI reports may come from at least one of {(1,1), (1,2), (1,3), (1,4), (2,1), (2,2), (2,3), (2,4), (3,1), (3,2), (3,3), (3,4), (4,1), (4,2), (4,3), (4,4)}, or may come from at least one of {(1,1), (1,2), (2,1), (2,2), (2,3), (3,2), (3,3), (3,4), (4,3), (4,4)}, and the number of bits of the RI combination report is 4. For another example, the reported values ​​of RI in two CSI reports may be combined values, and the reported values ​​of the RI combination of the two CSI reports may come from at least one of {(1, 1), (1, 2), (1, 3), (1, 4), (2, 1), (2, 2), (2, 3), (2, 4), (3, 3), (3, 4), (4, 4)}, or may come from at least one of {(1, 1), (2, 1), (2, 2), (3, 1), (3, 2), (3, 3), (4, 1), (4, 2), (4, 3), (4, 4)}, and the number of bits of the RI combination report is 4. For another example, the reported values ​​of RI in the two CSI reports may be combined values, and the reported values ​​of the RI combination of the two CSI reports may be from at least one of {(1, 1), (1, 2), (2, 2), (2, 3), (3, 3), (3, 4), (4, 4)}, or may be from at least one of {(1, 1), (2, 1), (2, 2), (3, 2), (3, 3), (4, 3), (4, 4)}, and the number of bits of the RI combination report is 3. In addition, based on the number of allowed RI values, combinations with restricted RI values ​​may be excluded, and the number of bits of the RI combination report may be further reduced.

[0092] In another aspect of the present disclosure, it further proposes a CSI reporting solution for beam scanning. In the beam report, there is a parameter "repeat" that controls the beam scanning mode. In the first mode, the parameter "repeat" is set to "on", and in this case, the network device will use the same beam during beam scanning, and the terminal device can select the receive beam. In the second mode, the parameter "repeat" is set to "off", and in this case, the network device will use different beams to send signaling during beam scanning, and the terminal device can select the transmission beam from the different beams used by the network device.

[0093] In the first mode, the reportQuantity reported by the terminal device can be "cri-RSRP" or "none" (nothing is reported); in the second mode, the terminal device can report "cri-RSRP". In the current technology, it is required that when RSRP is reported, it is always combined with CRI or SSBRI, but when the parameter "repeat" is set to "on", no CRI is reported. However, even if the parameter "repeat" is set to "on", CSI reporting may be beneficial because it can feed back the quality of the fixed transmission beam to the network device, so that the network device can know the situation where the fixed transmission beam does not have ideal channel quality.

[0094] In some embodiments of the present disclosure, instead of cri-RSRP, a new reportQuantity may be used to report CSI when the parameter "repetition" is set to "on". When the parameter "repetition" is set to "on", the new reportQuantity may contain information about "RSRP" or "SINR" used to report CSI.

[0095] In some embodiments of the present disclosure, the terminal device uses reportQuantity "cri-RSRP" to report CSI. reportQuantity "cri-RSRP" may contain information about the measured CRI or SSBRI and RSRP; however, when the parameter "repeat" is set to "on", the network device will ignore the reported value of CRI or SSBRI and only obtain information about the reported value of RSRP.

[0096] In some embodiments of the present disclosure, the terminal device still uses reportQuantity "cri-RSRP" to report CSI. In this case, reportQuantity "cri-RSRP" contains two information parts about CRI or SSBRI and RSRP; however, when the parameter "repeat" is set to "on", the information part about CRI or SSBRI contains only default values ​​or fixed values ​​(for example, all zeros or ones for each bit of CRI or SSBRI), instead of measured values. In this way, the network device can know that the report only contains useful RSRP information based on the default value or fixed value.

[0097] In some embodiments of the present disclosure, when the parameter "repeat" is set to "on", the terminal device still uses reportQuantity "cri-RSRP" to report CSI, but the information part about CRI or SSBRI only uses one bit, regardless of the number of resources in a set. In this way, the CSI report can have a lower signaling overhead.

[0098] In some embodiments of the present disclosure, for multi-TRP transmission, multiple CSI reports about multiple TRPs should be sent for each CSI-RS resource set, and the CSI-RS resource set can be divided into multiple resource subsets. For example, for 2TRP transmission, a CI-RS resource set including N CSI-RSs can be divided into two CSI-RS resource subsets, each with N / 2 CSI-RS resources. The first subset in the CSI-RS resource subset can be used for CSI acquisition of the first TRP, and the second subset in the CSI-RS subset can be used for CSI acquisition of the second TRP. In this case, the CRI only requires half the bit width, so the bit width of the CRI in Table 1 will become log2(N / 2).

[0099] Table 5 CSI report structure in NR system

[0100]

[0101] Figure 6 A flowchart of a method for receiving a CSI report at a network device according to some embodiments of the present disclosure is schematically shown. The method 600 may be performed at a network device (e.g., a base station such as a gNB or other similar device).

[0102] like Figure 6 As shown, first in step 610, the network device may receive a first CSI report on a first TRP among multiple TRPs serving a terminal device for a CSI-RS resource set used for CSI acquisition.

[0103] As described above, CSI reports may be configured by a network device. For example, CSI reports may be sent periodically, or alternatively, CSI reports may be sent after receiving a report request from a network device. After a terminal device performs CSI measurements using the CSI-RS resources selected for each TRP, it may obtain CSI information for each TRP. For one CSI-RS resource set used for CSI acquisition, a terminal device may send multiple sets of CSI reports for multiple TRPs, one report for each TRP.

[0104] Therefore, the network device may receive a first CSI report about the first TRP. The first CSI report may include the CRI and RI of the first TRP. In some embodiments of the present disclosure, the CSI report may also include any item of the PMI, CQI, and LI of the first TRP.

[0105] Next, in step 620, the network device receives a second CSI report about a second TRP in a plurality of TRPs serving the terminal device for the CSI-RS resource set. Similar to the first CSI report, the second CSI report may include a CRI and a rank indication RI of the second TRP. In some embodiments of the present disclosure, the CSI report may also include any of a PMI, a CQI, a layer indication, etc. of the second TRP.

[0106] In some embodiments of the present disclosure, the first CSI report may include the RI value of the first TRP, and the second CSI report may use an offset value relative to the RI value of the first TRP to indicate the RI value of the second TRP. In this way, the signaling overhead of the CSI report can be reduced. In such an embodiment, in step 630, the network device may also determine the rank indication value for the second TRP based on the offset value and the rank indication value for the first TRP.

[0107] In some embodiments of the present disclosure, the offset value may indicate that the rank indication value for the second TRP is higher, lower or equal to the rank indication value for the first TRP. For some detailed descriptions of the offset value indication, reference may be made to the contents of Table 2.

[0108] In some embodiments of the present disclosure, the offset value may indicate that the rank indication value for the second TRP is lower than or equal to the rank indication value for the first TRP. In some embodiments of the present disclosure, the offset value may indicate that the rank indication value for the second TRP is higher than or equal to the rank indication value for the first TRP. For some detailed descriptions of the offset value indication, reference may be made to the contents of Tables 3 to 4.

[0109] In some embodiments of the present disclosure, a CSI-RS resource set may be divided into multiple CSI-RS resource subsets for multiple TRPs, and wherein a first subset of the CSI-RS resource subsets is used for CSI acquisition of a first TRP, and a second subset of the CSI-RS subsets is used for CSI acquisition of a second TRP. For some detailed descriptions of the offset value indication, reference may be made to the contents of Table 5.

[0110] In the above, the above reference Figure 6 An example method for receiving CSI reports for multiple TRP transmissions at the network side is briefly described. However, it can be understood that the operation at the network device basically corresponds to the operation at the terminal device, so for some details of the operation, reference can be made to reference Figures 2 to 5 Description.

[0111] Figure 7 A block diagram of an apparatus for transmitting a CSI report for multi-TRP transmission at a terminal device according to some embodiments of the present disclosure is schematically shown. The apparatus 700 may be implemented at a terminal device (eg, a UE or other similar terminal device).

[0112] like Figure 7 As shown, the apparatus 700 may include a first CSI report transmission module 710 and a second CSI report transmission module 720. The first CSI report transmission module 710 may be configured to send a first CSI report about a first TRP among multiple TRPs of a serving terminal device for a channel state information reference signal (CSI-RS) resource set for CSI acquisition. The second CSI report transmission module 720 may be configured to send a second CSI report about a second TRP among multiple TRPs of a serving terminal device for a CSI-RS resource set.

[0113] In some embodiments of the present disclosure, a first CSI report may include a first rank indication regarding a first TRP, and a second CSI report may include a second rank indication regarding a second TRP, and wherein the first rank indication may indicate a rank indication value regarding the first TRP, and the second rank indication may indicate an offset value relative to the rank indication value regarding the first TRP.

[0114] In some embodiments of the present disclosure, the offset value may indicate that the rank indication value regarding the second TRP is higher, lower, or equal to the rank indication value regarding the first TRP.

[0115] In some embodiments of the present disclosure, one of multiple TRPs having a larger rank indication value may be determined as a first TRP, and wherein the offset value may indicate that the rank indication value regarding the second TRP is lower than or equal to the rank indication value regarding the first TRP.

[0116] In some embodiments of the present disclosure, one of multiple TRPs having a smaller rank indication value may be determined as a first TRP, and wherein the offset value may indicate that the rank indication value regarding the second TRP is higher than or equal to the rank indication value regarding the first TRP.

[0117] In some embodiments of the present disclosure, a CSI-RS resource set may be divided into multiple CSI-RS resource subsets for multiple TRPs, wherein a first subset of the CSI-RS resource subsets may be used for CSI acquisition of a first TRP, and a second subset of the CSI-RS subsets may be used for CSI acquisition of a second TRP.

[0118] In some embodiments of the present disclosure, each of the first CSI report and the second CSI report may include one or more of the following: a CSI-RS resource indication; a rank indication; a precoding matrix indicator; a channel quality indicator; and a layer indication.

[0119] Figure 8 A block diagram of an apparatus for receiving a CSI report for a multi-TRP transmission at a terminal device according to some embodiments of the present disclosure is schematically shown. The apparatus 800 may be implemented on a network device or node (e.g., a gNB or other similar network device).

[0120] like Figure 8 As shown, the apparatus 800 may include a first CSI report receiving module 810 and a second CSI report receiving module 820. The first CSI report receiving module 810 may be configured to receive a first CSI report on a first TRP among multiple TRPs of a serving terminal device for a channel state information reference signal (CSI-RS) resource set for CSI acquisition. The second CSI report receiving module 820 may be configured to receive a second CSI report on a second TRP among multiple TRPs of a serving terminal device for a CSI-RS resource set.

[0121] In some embodiments of the present disclosure, the first CSI report may include a first rank indication for a first TRP, and the second CSI report may include a second rank indication for a second TRP, and wherein the first rank indication is a rank indication value for the first TRP, and the second rank indication indicates an offset value relative to the rank indication value for the first TRP. In these embodiments, the apparatus 800 may further include an RI value determination module 830, which may be configured to determine a rank indication value for the second TRP based on the offset value and the rank indication value for the first TRP.

[0122] In some embodiments of the present disclosure, the offset value may indicate that the rank indication value regarding the second TRP is higher, lower, or equal to the rank indication value regarding the first TRP.

[0123] In some embodiments of the present disclosure, the offset value may indicate that the rank indication value regarding the second TRP is lower than or equal to the rank indication value regarding the first TRP.

[0124] In some embodiments of the present disclosure, the offset value may indicate that the rank indication value regarding the second TRP is higher than or equal to the rank indication value regarding the first TRP.

[0125] In some embodiments of the present disclosure, a CSI-RS resource set may be divided into multiple CSI-RS resource subsets for multiple TRPs, wherein a first subset of the CSI-RS resource subsets may be used for CSI acquisition of a first TRP, and a second subset of the CSI-RS subsets may be used for CSI acquisition of a second TRP.

[0126] In some embodiments of the present disclosure, each of the first CSI report and the second CSI report may include one or more of the following: a CSI-RS resource indication; a rank indication; a precoding matrix indicator; a channel quality indicator; and a layer indication.

[0127] In the above, briefly refer to Figure 7 and Figure 8 The apparatuses 700 and 800 are described. It should be noted that the apparatuses 700 to 800 may be configured to implement the Figures 2 to 6 Therefore, for details on the operation of the modules in these devices, reference can be made to the Figures 2 to 6 The corresponding steps of the method are described in detail.

[0128] It should also be noted that the components of apparatuses 700 and 800 may be implemented in hardware, software, firmware and / or any combination thereof. For example, the components of apparatuses 700 and 800 may be implemented by circuits, processors or any other suitable selection devices, respectively.

[0129] Those skilled in the art will understand that the above examples are for illustration only and not limitation, and the present disclosure is not limited thereto; many changes, additions, deletions and modifications can be easily conceived from the teachings provided herein, and all such changes, additions, deletions and modifications fall within the scope of protection of the present disclosure.

[0130] In addition, in some embodiments of the present disclosure, the apparatuses 700 and 800 may include at least one processor. As an example, the at least one processor suitable for use with the embodiments of the present disclosure may include both general-purpose and special-purpose processors known or developed in the future. The apparatuses 700 and 800 may also include at least one memory. The at least one memory may include, for example, semiconductor memory devices such as RAM, ROM, EPROM, EEPROM, and flash memory devices. The at least one memory may be used to store a program of computer executable instructions. The program may be written in any high-level and / or low-level compatible or decipherable programming language. According to an embodiment, the computer executable instructions may be configured to cause the apparatuses 700 and 800 to perform at least one of the following operations, respectively, together with the at least one processor: Figures 2 to 6 Operation of the method discussed.

[0131] Fig. 9 A simplified block diagram of an apparatus 910 as described herein that may be implemented as or included in a terminal device such as a UE and an apparatus 920 that may be implemented as or included in a network device such as a gNB is schematically shown.

[0132] The device 910 includes at least one processor 911, such as a data processor (DP), and at least one memory (MEM) 912 coupled to the processor 911. The device 910 may also include a transmitter TX and a receiver RX 913 coupled to the processor 911, and the transmitter TX and the receiver RX 913 are operable to be communicatively connected to the device 920. The MEM 912 stores a program (PROG) 914. The PROG 914 may include instructions that enable the device 910 to operate according to an embodiment of the present disclosure (e.g., method 200) when executed on the associated processor 911. The combination of the at least one processor 911 and the at least one MEM 912 may form a processing component 915 adapted to implement various embodiments of the present disclosure.

[0133] The device 920 includes at least one processor 911 (such as a DP) and at least one MEM 922 coupled to the processor 911. The device 920 may also include a suitable TX / RX 923 coupled to the processor 921, which may be operable to wirelessly communicate with the device 910. The MEM 922 stores a PROG 924. The PROG 924 may include instructions that, when executed on the associated processor 921, enable the device 920 to operate according to embodiments of the present disclosure, for example, to perform the method 600. The combination of the at least one processor 921 and the at least one MEM 922 may form a processing component 925 adapted to implement various embodiments of the present disclosure.

[0134] Various embodiments of the present disclosure may be implemented by a computer program executable by one or more of the processors 911 , 921 , software, firmware, hardware, or a combination thereof.

[0135] MEMs 912 and 922 may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as, by way of non-limiting example, semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory.

[0136] Processors 911 and 921 may be of any type suitable for the local technical environment, and may include, by way of non-limiting example, one or more of: a general purpose computer, a special purpose computer, a microprocessor, a digital signal processor DSP, and a processor based on a multi-core processor architecture.

[0137] In addition, the present disclosure may also provide a carrier containing the computer program as described above, wherein the carrier is one of an electric signal, an optical signal, a radio signal or a computer-readable storage medium. The computer-readable storage medium may be, for example, an optical disc or an electronic memory device, such as a RAM (random access memory), a ROM (read-only memory), a flash memory, a magnetic tape, a CD-ROM, a DVD, a Blu-ray disc, etc.

[0138] The techniques described herein may be implemented by various means so that the device implementing one or more functions of the corresponding device described using the embodiments includes not only prior art components, but also components for implementing one or more functions of the corresponding device described using the embodiments, and it may include separate components for each separate function, or may include components that can be configured to perform two or more functions. For example, these techniques may be implemented in hardware (one or more devices), firmware (one or more devices), software (one or more modules), or a combination thereof. For firmware or software, implementation may be performed by modules (e.g., processes, functions, etc.) that perform the functions described herein.

[0139] Exemplary embodiments herein have been described above with reference to block diagrams and flowchart illustrations of methods and apparatus. It should be understood that each block of the block diagrams and flowchart illustrations and the combination of the blocks of the block diagrams and flowcharts can be implemented by various components including computer program instructions, respectively. These computer program instructions can be loaded onto a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine, so that the instructions executed on the computer or other programmable data processing device create components for implementing the functions specified in one or more flowchart blocks.

[0140] Although this specification contains many specific implementation details, these should not be interpreted as limitations on the scope of any implementation or possible claimed content, but rather as descriptions of features of specific embodiments that may be specific to a specific implementation. Certain features described in the context of separate embodiments in this specification may also be implemented in combination in a single embodiment. On the contrary, the various features described in the context of a single embodiment may also be implemented in multiple embodiments or in any suitable sub-combination, respectively. Moreover, although the features may be described above as working in certain combinations and even initially claimed as such, in some cases, one or more features in the claimed combination may be excluded from the combination, and the claimed combination may involve a sub-combination or a variant of a sub-combination.

[0141] It is clear to those skilled in the art that, with the advancement of technology, the concept of the present invention can be implemented in various ways. The above embodiments are given for description rather than limitation of the present disclosure, and it should be understood that, as readily understood by those skilled in the art, modifications and changes can be made without departing from the spirit and scope of the present disclosure. Such modifications and changes are considered to be within the scope of the present disclosure and the appended claims. The scope of protection of the present disclosure is defined by the appended claims.

Claims

1. A method performed by a terminal device, comprising: Receiving a configuration for channel state information (CSI) reporting from a network device; as well as The CSI report is sent to the network device, wherein the CSI report includes a first rank indication RI and a second RI, the first RI is associated with a first CSI-RS resource subset of a channel state information reference signal CSI-RS resource set, the second RI is associated with a second CSI-RS resource subset of the CSI-RS resource set, and the first RI and the second RI are reported as a combination value corresponding to one of {(1,1), (1,2), (2,1), (2,2)}, and the CSI report also includes a first precoding matrix indicator PMI associated with the first CSI-RS resource subset and a second PMI associated with the second CSI-RS resource subset.

2. The method according to claim 1, wherein the CSI report further comprises: A first layer indication LI associated with the first CSI-RS resource subset and a second LI associated with the second CSI-RS resource subset.

3. A method performed by a network device, comprising: Sending a configuration for channel state information (CSI) reporting to a terminal device; as well as The CSI report is received from the terminal device, wherein the CSI report includes a first rank indication (RI) and a second RI, wherein the first RI is associated with a first CSI-RS resource subset of a channel state information reference signal (CSI-RS) resource set, and the second RI is associated with a second CSI-RS resource subset of the CSI-RS resource set, and the first RI and the second RI are reported as a combination value corresponding to one of {(1,1), (1,2), (2,1), (2,2)}, and the CSI report also includes a first precoding matrix indicator (PMI) associated with the first CSI-RS resource subset and a second PMI associated with the second CSI-RS resource subset.

4. The method according to claim 3, wherein the CSI report further comprises: A first layer indication LI associated with the first CSI-RS resource subset and a second LI associated with the second CSI-RS resource subset.

5. A terminal device, comprising: transceiver, and A processor is configured to execute or control the transceiver to execute the method according to any one of claims 1 to 2.

6. A network device comprising: Transceiver; as well as A processor is configured to execute or control the transceiver to execute the method according to any one of claims 3 to 4.

7. A terminal device, comprising processor, and A memory is coupled to the processor and has program code therein, wherein the program code, when executed on the processor, causes the terminal device to perform the operation according to any one of claims 1 to 2.

8. A network device comprising processor, and A memory coupled to the processor and having program code therein, the program code causing the network device to perform operations according to any one of claims 3 to 4 when executed on the processor.

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