CSI measurement for multi-TRP / panel transmission

Abstract

Embodiments of the present disclosure relate to methods, devices, and apparatus for channel state information (CSI) measurement, and methods, devices, and apparatus for transmitting CSI reference signals. In an embodiment of the present disclosure, a CSI-RS resource configuration is received from a network device, and the CSI-RS resource configuration indicates a CSI-RS resource set including multiple CSI-RS resources. Then, CSI measurement is performed using one of multiple CSI-RS resource combinations, wherein the multiple CSI-RS resource combinations are determined from the CSI-RS resource set based on a predefined combination rule. Using embodiments of the present disclosure, it is feasible to support CSI measurements for multi-TPR / multi-panel transmissions.

Description

Technical Field

[0001] Non-limiting and exemplary embodiments of the present disclosure generally relate to the field of wireless communication technology, and more particularly to methods, devices, and apparatuses for channel state information (CSI) measurement and methods, devices, and apparatuses for transmitting a CSI reference signal (CSI-RS). Background Art

[0002] The New Radio Access System (also known as the NR system or NR network) is the next generation communication system. At the Radio Access Network (RAN) #71 meeting of the Third 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 to have a single technical framework to address all usage scenarios, requirements, and deployment scenarios defined in the technical report TR38.913, including 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 in NR systems.

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

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

[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 and per PDSCH / PUSCH assignment

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

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

[0012] • An uplink (UL) or downlink (DL) related downlink control indication (DCI) includes a modulation and coding scheme (MCS) on a CW-by-CW basis.

[0013] Calculate a channel quality indicator (CQI) per CW

[0014] Regarding CSI resources in NR, it was also agreed that:

[0015] CSI-RS resources with 1-port and 2-port for one OFDM symbol can be used for beam management

[0016] • When applicable, the UE may assume that all CSI-RS ports within one CSI-RS resource are quasi co-located with respect to “QCL ​​Type A” and “QCL ​​Type D”.

[0017] With regard to single PDSCH and multiple PDSCHs from separate TRPs, it is further agreed that:

[0018] For NR reception, take the following actions:

[0019] - A single NR-PDCCH schedules a single NR-PDSCH, where separate layers are transmitted from separate TRPs

[0020] - Multiple NR-PDCCHs, each NR-PDCCH scheduling a corresponding NR-PDSCH, where each NR-PDSCH is transmitted from a separate TRP

[0021] - NOTE: The case where a single NR-PDCCH schedules a single NR-PDSCH can be done in a specification-transparent manner, where each layer is transmitted jointly from all TRPs

[0022] -Note: Details of CSI feedback for the above situations can be discussed separately

[0023] Multi-TRP / panel transmission is deprioritized and therefore not discussed in detail in Release 15. Therefore, the current NR, CSI-RS configuration, and transmission configuration indication (TCI) state configuration are based on a single TRP / panel. For multi-TRP transmission, the TRP is not QCL processed, and therefore, the solution for CSI measurement and reporting for single TRP transmission cannot be applied to multi-TRP / panel transmission. Summary of the invention

[0024] To this end, in the present disclosure, a new solution for CSI measurement in a wireless communication system is provided to alleviate or at least mitigate at least part of the problems in the prior art.

[0025] According to a first aspect of the present disclosure, a method for CSI measurement in a wireless communication system is provided. The method may include: receiving a CSI reference signal (CSI-RS) resource configuration from a network device, the CSI-RS resource configuration indicating a CSI-RS resource set including multiple CSI-RS resources; and performing CSI measurement using one of multiple CSI-RS resource combinations, the multiple CSI-RS resource combinations being determined from the CSI-RS resource set based on a predefined combination rule.

[0026] According to a second aspect of the present disclosure, a method for transmitting CSI-RS in a wireless communication system is provided. The method may include: transmitting a CSI-RS resource configuration to a terminal device, the CSI-RS resource configuration indicating a CSI-RS resource set including multiple CSI-RS resources; and transmitting the CSI-RS using one of multiple CSI-RS resource combinations, wherein the multiple CSI-RS resource combinations are determined from the CSI-RS resource set based on a predefined combination rule.

[0027] According to a third aspect of the present disclosure, a terminal device is provided, wherein the terminal device is configured for CSI measurement. The terminal device may include a transceiver and a processor, wherein the processor is configured to execute or control the transceiver: receiving a CSI-RS resource configuration from a network device, wherein the CSI-RS resource configuration indicates a CSI-RS resource set including multiple CSI-RS resources; and performing CSI measurement using one of multiple CSI-RS resource combinations, wherein the multiple CSI-RS resource combinations are determined from the CSI-RS resource set based on a predefined combination rule.

[0028] According to a fourth aspect of the present disclosure, a network device is provided, wherein the network device is configured to transmit a CSI-RS. The network device may include a transceiver and a processor, wherein the processor is configured to execute or control the transceiver: transmitting a CSI-RS resource configuration to a terminal device, wherein the CSI-RS resource configuration indicates a CSI-RS resource set including multiple CSI-RS resources; and transmitting the CSI-RS using one of multiple CSI-RS resource combinations, wherein the multiple CSI-RS resource combinations are determined from the CSI-RS resource set based on a predefined combination rule.

[0029] 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 the operation of the method according to any embodiment of the first aspect.

[0030] 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 the operation of the method according to any embodiment of the second aspect.

[0031] According to a seventh aspect of the present disclosure, there is provided a computer-readable storage medium on which a computer program code is embodied. The computer program code is configured to cause an apparatus to perform actions of the method according to any embodiment of the first aspect when executed.

[0032] According to an eighth aspect of the present disclosure, there is provided a computer-readable storage medium on which a computer program code is embodied. The computer program code is configured to cause an apparatus to perform actions of the method according to any embodiment of the second aspect when executed.

[0033] 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.

[0034] According to a tenth aspect of the present disclosure, a computer program product is provided, comprising a computer-readable storage medium according to the eighth aspect.

[0035] Utilizing the embodiments of the present disclosure, a new solution for CSI measurement is provided, which makes it feasible to support CSI measurement for multi-TRP / panel transmission. 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 the same reference numerals represent the same or similar components throughout the drawings, and in which:

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

[0038] Figure 2 A flow chart of a method for CSI measurement at a terminal device according to some embodiments of the present disclosure is illustrated;

[0039] Figure 3 illustrates TCI configuration for CSI-RS according to some embodiments of the present disclosure;

[0040] Figure 4 A flow chart of a method for transmitting CSI-RS at a network device according to some embodiments of the present disclosure is illustrated;

[0041] Figure 5A block diagram schematically illustrates an apparatus for CSI measurement at a terminal device according to some embodiments of the present disclosure;

[0042] Figure 6 A block diagram schematically illustrates an apparatus for transmitting a CSI-RS at a network device according to some embodiments of the present disclosure;

[0043] Figure 7 A diagram illustrating TCI configuration for PDSCH in dual TRP transmission according to some embodiments of the present disclosure; and

[0044] Figure 8 A simplified block diagram of an apparatus 810 as described herein that may be embodied as or included in a terminal device such as a UE and an apparatus 820 that may be embodied as or included in a network device such as a gNB is schematically illustrated. DETAILED DESCRIPTION

[0045] 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.

[0046] 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, the assignable frame is shown with a dotted line. 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 the order shown. For example, they can be performed in reverse order 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 system based on dedicated hardware for performing a specified function / operation, or can be implemented by a combination of dedicated hardware and computer instructions.

[0047] In general, unless otherwise expressly defined herein, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field. Unless otherwise expressly stated, all references to "a / an / the / said [element, device, component, means, step, etc.]" should be openly interpreted as referring to at least one instance of the element, device, component, means, unit, step, etc., without excluding a plurality of such devices, components, means, 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.

[0048] 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, an 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, a pico, etc.).

[0049] As mentioned above, in Release 15 of the NR system, the CSI-RS configuration and TCI state configuration are based on a single TRP / panel. Although for multi-TRP transmission, the TRP is not QCL, and therefore, the CSI measurement and reporting solution for single TRP transmission cannot be applied to multi-TRP / panel transmission.

[0050] Embodiments of the present disclosure provide a solution for CSI measurement. The basic idea is to transmit a CSI-RS resource configuration at a network device to indicate a CSI-RS resource set including multiple CSI-RS resources, and both the network device and the terminal device determine multiple CSI-RS resource combinations from the CSI-RS resource set, and select a combination for CSI measurement. With the help of CSI-RS resource sets and predefined combination rules, CSI measurement for multi-TPR / multi-panel transmission can be supported. In addition, in different aspects, a solution for TCI configuration of PDSCH or PDCCH is also proposed.

[0051] In some embodiments of the present disclosure, a terminal device receives a CSI-RS resource configuration indicating a CSI-RS resource set including a plurality of CSI-RS resources from a network device, and performs CSI measurement using one of a plurality of CSI-RS resource combinations, the plurality of CSI-RS resource combinations being determined from the CSI-RS resource set based on a predefined combination rule. The network device transmits a CSI-RS resource configuration indicating a CSI-RS resource set to a terminal device, the CSI-RS resource set including a plurality of CSI-RS resources, and transmits CSI-RS using one of a plurality of CSI-RS resource combinations determined from the CSI-RS resource set based on a predefined combination rule.

[0052] Please note that the basic ideas and embodiments of the present disclosure can be used for multi-TRP transmission. When they are used for multi-panel transmission, CSI-RS transmission is performed through the corresponding TRPs used for multi-TRP transmission, and CSI measurements will be performed for these TRPs separately. It should also be understood that the basic ideas and embodiments 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 means transmission using multiple panels for a single user device. When the basic ideas and embodiments are used for multi-panel transmission, CSI-RS transmission is performed through the corresponding panels used for multi-panel transmission, and CSI measurements will be performed for these panels instead of the corresponding TRPs separately.

[0053] In the following, reference will be made to Figures 1 to 8 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. The embodiments of the present disclosure may also be used for multi-panel transmission. And more specifically, 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.

[0054] Figure 1 An example scenario in which the multi-TRP transmission of the present disclosure can be implemented is illustrated. Figure 1 , dual TRP transmission is illustrated, where a single UE 110 can be served by two TRPs. As shown, the UE 110 can simultaneously receive signals such as CSI-RS from both TRP1 120 and TRP2 130. The embodiments of the present disclosure are only related to such example scenarios to provide a new solution for CSI measurement.

[0055] Figure 2 The flowchart of a method for performing CSI 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).

[0056] like Figure 2 As shown, in step 210, the terminal device receives a CSI-RS resource configuration from the network device, wherein the CSI-RS resource configuration indicates a CSI-RS resource set including a plurality of CSI-RS resources. In an embodiment of the present disclosure, the CSI-RS resource configuration will be transmitted to the terminal device to indicate the CSI-RS resource set configured for the terminal device. The CSI-RS resource configuration can be transmitted to the terminal device in various ways, such as through RRC signaling, MAC CE, or physical layer signaling.

[0057] Next, in step 220, the terminal device performs CSI measurement using one of a plurality of CSI-RS resource combinations, wherein the plurality of CSI-RS resource combinations are determined from the CSI-RS resource set based on a predefined combination rule. In an embodiment of the present disclosure, a predetermined combination rule may be used to determine a plurality of CSI-RS resource combinations from a CSI-RS resource set indicated by a CSI-RS resource configuration. The predetermined combination rule is known to both the network device and the terminal device, and in this way, both of them may determine the same CSI-RS resource combination from the same CSI-RS resource set. Then, for example, one of a plurality of CSI-RS resource combinations may be selected from a plurality of CSI-RS resource combinations based on the channel quality of the corresponding combination for CSI measurement.

[0058] In some embodiments of the present disclosure, each of the multiple CSI-RS resource combinations includes: a combination of ports of a CSI-RS resource from a CSI-RS resource set. In other words, according to a predetermined combination rule, a CSI-RS resource with N ports will be decomposed (disaggregate) into M subsets, and each subset contains N / M ports, and these combinations can come from combining the ports in these subsets. For example, for dual TRP transmission, for the purpose of beam management, a CSI-RS resource set with two or four ports in one symbol can be configured for a terminal device. In this case, for a CSI-RS resource set with two ports, one port can be used for TRP1 and the other port can be used for TRP2. In addition, the two ports may not be code domain multiplexed (CDM). As another example, for a CSI-RS resource set with four ports, two ports can be used for TRP1 and the other two ports can be used for TRP2. Then, further based on a predetermined combination rule known to both the terminal device and the network device, multiple CSI-RS resource combinations for TRP1 and TRP2 can be obtained from the aggregated subset. In addition, different subsets may have different power ratios, in other words, at least two resources in the CSI-RS resource combination may have different power ratios.

[0059] In some embodiments of the present disclosure, each of the multiple CSI-RS resource combinations includes a combination of CSI-RS resources from a CSI-RS resource set. In other words, according to a predetermined combination rule, a CSI-RS resource set having K CSI-RS resources can be divided or grouped into L subsets, each subset containing K / L resources, and these combinations can be derived by combining the resources in these subsets. For example, for dual TRP transmission, the number of CSI-RS resources contained in the CSI-RS resource set K (e.g., R1, R2, ... R K-1 , R K ) is a multiple of 2. Therefore, from the K / 2 CSI resources, based on a predetermined combination rule known to both the terminal device and the network device, multiple resource combinations (pairs) can be formed, and each pair contains two CSI-RS resources. For example, a CSI-RS resource pair may include a pair with two consecutive indexes {(R1, R2), (R3, R4), ..., (R K-1 , R K )}. For another example, K CSI-RS resources can be divided into two subsets {R1, R2, ... R K / 2-1 , R K / 2} and {R K / 2+1 , R K / 2+2 , … R K-1 , R K} and a CSI-RS resource pair may include CSI-RS resources from two subsets {(R1, R K / 2+1 ), (R2, R K / 2+2 ),...,(R K / 2-1 , R K-1 ), (R K / 2 , R K )}. In addition, different subsets may have different power ratios, and in other words, at least two resources in the CSI-RS resource combination may have different power ratios.

[0060] In some embodiments of the present disclosure, the resources in the CSI-RS resource combination are located in the same time slot or consecutive time slots, or the resources in the CSI-RS resource combination have an interval of less than a predetermined number of symbols between them, especially for beam management, CSI acquisition, beam scanning or beam tracking. For example, for beam management in the case of dual TRP transmission, two CSI resources in a CSI-RS resource pair are frequency-division multiplexed in one symbol, and each CSI-RS resource may include one or two ports.

[0061] In some embodiments of the present disclosure, the CSI-RS port in the CSI-RS resource combination may be non-QCL, and therefore, in step 330, the terminal device may also receive at least two transmission configuration indications (TCIs) from the network device. Figure 3 As shown, two TCIs for at least two CSI-RS ports in a CSI resource combination can be transmitted from a network device to a terminal device accordingly. At least two TCIs, in particular two TCI state identities (IDs), are directed to at least two subsets decomposed from a CSI-RS resource set. Therefore, when performing CSI measurements, at least two quasi-co-location (QCL) configurations indicated by at least two TCIs can also be used. In other words, CSI measurements can be performed by using a CSI-RS resource combination with at least two quasi-co-location (QCL) configurations indicated by at least two TCIs in a plurality of CSI-RS resource combinations.

[0062] Figure 4 A flowchart of a method for transmitting CSI-RS according to an embodiment of the present disclosure is also illustrated. Method 400 may be performed at a network device (e.g., a base station such as a gNB or other similar device).

[0063] like Figure 4 As shown, first in step 410, the network device may transmit a CSI-RS resource configuration to the terminal device, wherein the CSI-RS resource configuration indicates a CSI-RS resource set including multiple CSI-RS resources. In an embodiment of the present disclosure, the CSI-RS resource set configured for the terminal device may be indicated by the CSI-RS resource configuration. The CSI-RS configuration may be transmitted to the terminal device in various ways, such as through RRC signaling, MAC CE, or physical layer signaling.

[0064] Then, in step 420, the network device transmits CSI-RS using one of the multiple CSI-RS resource combinations, where the multiple CSI-RS resource combinations are determined from the CSI-RS resource set based on a predefined combination rule. In an embodiment of the present disclosure, a predetermined combination rule can be used to determine multiple CSI-RS resource combinations from a CSI-RS resource set configured for a terminal device. The predetermined combination rule is known to both the network device and the terminal device, and in this way, both of them can determine the same CSI-RS resource combination from the same CSI-RS resource set. Then, for example, one of the multiple CSI-RS resource combinations can be selected from the multiple CSI-RS resource combinations based on the channel quality of the corresponding combination for CSI measurement.

[0065] In some embodiments of the present disclosure, each CSI-RS resource combination in a plurality of CSI-RS resource combinations contains a combination of ports of a CSI-RS resource from a CSI-RS resource set. In other words, according to a predetermined combination rule, a CSI-RS resource with N ports will be decomposed into M subsets, and each subset contains N / M ports, and these combinations can be derived from combining the ports in these subsets.

[0066] In some embodiments of the present disclosure, each of the multiple CSI-RS resource combinations contains a combination of CSI-RS resources from a CSI-RS resource set. In other words, according to a predetermined combination rule, a CSI-RS resource set with K CSI-RS resources can be divided or grouped into L subsets, each subset containing K / L resources, and these combinations can be derived by combining the resources in these subsets.

[0067] In some embodiments of the present disclosure, the resources in the CSI-RS resource combination are located in the same time slot. Alternatively, the resources in the CSI-RS resource combination are located in consecutive time slots. Or alternatively, the resources in the CSI-RS resource combination have a spacing between them that is less than a predetermined number of symbols.

[0068] In some embodiments of the present disclosure, at least two resources in a CSI-RS resource combination may have different power ratios.

[0069] In some embodiments of the present disclosure, in step 430, the terminal device may also transmit at least two transmission configuration indications (TCIs) of at least two CSI-RS ports in the CSI resource combination to the terminal device. In this case, CSI-RS transmission may be performed using at least two QCL configurations indicated by at least two TCIs. In other words, CSI-RS may be transmitted using one CSI-RS resource combination having at least two QCL configurations indicated by at least two TCIs among multiple CSI-RS resource combinations.

[0070] In some embodiments of the present disclosure, the CSI reference signal may be transmitted via multiple transmission reception point (TRP) points for TRP transmission.

[0071] In some embodiments of the present disclosure, the CSI measurement reference signal may be transmitted through a plurality of panels for multi-panel transmission.

[0072] In the above, the above reference Figure 4 An example method for transmitting CSI-RS on 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 Figures 1 to 3Description.

[0073] Figure 5 The block diagram of an apparatus for performing CSI transmission at a terminal device according to some embodiments of the present disclosure is schematically illustrated. The apparatus 500 may be implemented at a terminal device (eg, a UE or other similar terminal device).

[0074] like Figure 5 As shown, the apparatus 500 may include a configuration receiving module 510 and a CSI measurement report 520. The configuration receiving module 510 is configured to receive a CSI-RS resource configuration from a network device, wherein the CSI-RS resource configuration indicates a CSI-RS resource set including multiple CSI-RS resources. The CSI measurement module 520 is configured to perform CSI measurement using one of multiple CSI-RS resource combinations, wherein the multiple CSI-RS resource combinations may be determined from the CSI-RS resource set based on a predefined combination rule.

[0075] In some embodiments of the present disclosure, each CSI-RS resource combination in the plurality of CSI-RS resource combinations may include a combination of ports from one CSI-RS resource in a CSI-RS resource set.

[0076] In some embodiments of the present disclosure, each CSI-RS resource combination in the plurality of CSI-RS resource combinations may include a combination of CSI-RS resources from a CSI-RS resource set.

[0077] In some embodiments of the present disclosure, the resources in a CSI-RS resource combination may be located in the same time slot; or the resources in a CSI-RS resource combination may be located in consecutive time slots, or the resources in a CSI-RS resource combination may have intervals therebetween that are less than a predetermined number of symbols.

[0078] In some embodiments of the present disclosure, at least two resources in a CSI-RS resource combination may have different power ratios.

[0079] In some embodiments of the present disclosure, the apparatus 500 further includes a TCI receiving module 530 configured to receive at least two transmission configuration indications (TCIs) from a network device. In such an embodiment, the CSI measurement module may also be configured to perform CSI measurement using one CSI-RS resource combination of multiple CSI-RS resource combinations having at least two quasi co-location (QCL) configurations indicated by at least two TCIs.

[0080] In some embodiments of the present disclosure, CSI measurements may be performed for multiple transmission reception point (TRP) transmissions.

[0081] In some embodiments of the present disclosure, CSI measurements may be performed for multiple panels of a multi-panel transmission.

[0082] Figure 6 A block diagram of an apparatus for transmitting CSI-RS at a network device according to some embodiments of the present disclosure is schematically illustrated. The apparatus 600 may be implemented on a network device or node (e.g., a gNB or other similar network device).

[0083] like Figure 6 As shown, the apparatus 600 may include a configuration transmission module 610 and a CSI-RS transmission module 620. The configuration transmission module 610 may be configured to transmit a CSI reference signal (CSI-RS) resource configuration to a terminal device, wherein the CSI-RS resource configuration indicates a CSI-RS resource set including a plurality of CSI-RS resources. The CSI-RS transmission module 620 may be configured to transmit the CSI-RS using one of a plurality of CSI-RS resource combinations, wherein the plurality of CSI-RS resource combinations may be determined from the CSI-RS resource set based on a predefined combination rule.

[0084] In some embodiments of the present disclosure, each CSI-RS resource combination in the plurality of CSI-RS resource combinations may include a combination of ports from one CSI-RS resource in a CSI-RS resource set.

[0085] In some embodiments of the present disclosure, each CSI-RS resource combination in the plurality of CSI-RS resource combinations may include a combination of CSI-RS resources from a CSI-RS resource set.

[0086] In some embodiments of the present disclosure, the resources in the CSI-RS resource combination may be located in the same time slot. Alternatively, the resources in the CSI-RS resource combination are located in consecutive time slots. Or alternatively, the resources in the CSI-RS resource combination may have a spacing of less than a predetermined number of symbols therebetween.

[0087] In some embodiments of the present disclosure, at least two CSI-RS resource combinations among the multiple CSI-RS resource combinations may have different power ratios.

[0088] In some embodiments of the present disclosure, the apparatus 600 may further include a TCI transmission module 630 configured to transmit at least two transmission configuration indications (TCIs) to the terminal device. The CSI-RS transmission module may also be configured to transmit the CSI-RS using one CSI-RS resource combination having at least two quasi-co-location (QCL) configurations indicated by at least two TCIs among the multiple CSI-RS resource combinations.

[0089] In some embodiments of the present disclosure, a CSI reference signal may be transmitted via multiple transmission reception point (TRP) points for transmission.

[0090] In some embodiments of the present disclosure, the CSI measurement reference signal may be transmitted through multiple panels for multi-panel transmission.

[0091] In the above, briefly refer to Figure 5 and Figure 6 The apparatuses 500 and 600 are described. It should be noted that the apparatuses 500 to 600 may be configured to implement the Figures 1 to 4 Therefore, for details on the operation of the modules in these devices, please refer to the Figures 1 to 4 The following is a description of the corresponding steps of the method.

[0092] It should also be noted that the components of apparatuses 500 and 600 may be embodied in hardware, software, firmware and / or any combination thereof. For example, the components of apparatuses 500 and 600 may be implemented by circuits, processors or any other suitable selection devices, respectively.

[0093] On the other hand, a solution for TCI configuration for multi-TRP / panel transmission is also provided, which can be implemented alone or in combination with the above CSI measurement solution. In this aspect, the basic idea is to provide two TCIs from the network device for signal transmission, such as PDSCH or PDCCH.

[0094] In some embodiments of the present disclosure, Figure 7 As shown, at least two transmission configuration indications (TCIs) can be transmitted from a network device in a single physical downlink control channel (PDCCH), and the PDSCH can be received based on the relationship between the scheduling offset between the PDCCH and the PDSCH and the threshold time required to start transmission in a predetermined direction after scheduling. Hereinafter, this aspect of the present disclosure will be described by taking dual TRP transmission as an example; however, it should be noted that embodiments of the present disclosure can also be used for multi-panel transmission or multi-TRP transmission involving more than two TRPs.

[0095] For dual TRP transmission, if the two TRPs are from different serving cells or different bandwidth parts (BWP), one PDSCH can be configured with two TCI state IDs for two different serving cells or BWPs, respectively. If the scheduling offset is not less than the threshold time, the terminal device can assume that, with respect to the QCL configuration indicated by the TCI, the antenna port of each demodulation reference signal (DMRS) port group of the PDSCH is quasi-QCL with the RS in the corresponding TCI state. Therefore, in this case, the network device can transmit the PDSCH using the two QCL configurations indicated by the two TCIs, and the terminal device can receive the PDSCH using the two QCL configurations indicated by the two TCIs. On the other hand, if the scheduling offset is less than and / or equal to the threshold time, the network device and the terminal device can operate in different ways.

[0096] In some embodiments of the present disclosure, one or more CORESETs within the active BWP of one of the serving cells are configured for the UE, and the index of the serving cell in the configured TCI state is the same as the index in the previous PDCCH (just like the latest one). In this case, the network device can use the default QCL configuration for the serving cell, and the terminal device can use the default QCL configuration for the serving cell, and discard the signal from the TRP in other serving cells. For example, the terminal device can assume that, with respect to the QCL configuration for the lowest CORREST-ID in the latest time slot, the antenna port of the DMRS port group of the PDSCH is quasi-QCL with the RS in the TCI state (where one or more CORESETs within the active BWP of the serving cell are configured for the UE), and the lowest CORREST-ID in the latest time slot is regarded as the default QCL configuration.

[0097] In some embodiments of the present disclosure, one or more CORESETs within the active BWP of each serving cell are configured for the UE, and in this case, the network device and the terminal device may use two default QCL configurations for the two serving cells, respectively. For example, the terminal device may regard the two lowest CORREST-IDs in the latest time slot as the default QCL configuration for the corresponding serving cell.

[0098] In some embodiments of the present disclosure, if the scheduling offset is less than and / or equal to a threshold, the network device and the terminal device may assume that the two DMRS groups are QCLed and have the same TCI state as the lowest CORESET ID, regardless of whether the two DMRS groups are configured with the same TCI state or different TCI states. In other words, the network device and the terminal device will regard the lowest CORREST-ID in the latest time slot as the default QCL configuration, stop multi-TRP transmission and switch back to single TRP transmission.

[0099] In some embodiments of the present disclosure, for cross-carrier or cross-TRP scheduling, if the scheduling offset is less than and / or equal to a threshold, the CIF field may be ignored, and the PDSCH may be transmitted in the self-carrier or self-TRP, and the lowest COREST ID in the latest time slot may be used as the default QCL configuration. In other words, the network device and the terminal device will stop cross-carrier or cross-TRP scheduling and switch back to self-carrier or self-TRP scheduling.

[0100] In some embodiments of the present disclosure, for multi-panel transmission, at least two transmission configuration indicators (TCIs) for PDCCH reception may be transmitted from the network device in a single MAC CE, and PDCCH reception may be performed based on the scheduling offset between the MAC CE transmission and the PDCCH and the threshold time required to start transmission in a predetermined direction.

[0101] For example, the UE may have N panels, and the PDCCH may be received based on M panels (1 <= M < N) among the N panels. Taking two-panel transmission as an example, a UE may have two types of QLC for D, while other QCL types may be the same for the two panels. Two TCIs may be selected for the PDCCH of the two panels and transmitted to the terminal device via the MAC CE.

[0102] For various cases where the scheduling offset is not less than the threshold time and the scheduling offset is not less than the threshold time, the default QCL configuration may be determined in the same manner as described for the transmission configuration indicator regarding the PDSCH.

[0103] In some embodiments of the present disclosure, the scheduling offset is not less than the threshold time, and in this case, the terminal device may receive the PDCCH from different panels using the QCL configuration indicated by at least two TCIs.

[0104] In some embodiments of the present disclosure, the scheduling offset is less than and / or equal to the threshold time, and in this case, the terminal device may receive the PDCCH using the default QCL configuration of the previous PDCCH of the corresponding panel and discard the signals from other panels.

[0105] In some embodiments of the present disclosure, the scheduling offset is less than the threshold time, and in this case, the terminal device may receive the PDCCH using at least two default QCL configurations of the previous PDCCH of the corresponding panel.

[0106] In some embodiments of the present disclosure, the scheduling offset is less than and / or equal to the threshold time, and in this case, the terminal device may receive the PDCCH using the default QCL configuration of the previous PDCCH for the corresponding panel and stop multi-panel transmission.

[0107] In addition, it should be understood that at the network device, corresponding operations will also be performed to implement TCI configuration, and for details, reference may be made to the description of the operations at the terminal device.

[0108] Figure 8 A simplified block diagram of an apparatus 810 as described herein that may be embodied as or included in a terminal device such as a UE and an apparatus 820 that may be embodied as or included in a network device such as a gNB is schematically illustrated.

[0109] The device 810 includes at least one processor 811, such as a data processor (DP), and at least one memory (MEM) 812 coupled to the processor 811. The device 810 may also include a transmitter TX and a receiver RX 813 coupled to the processor 811, and the transmitter TX and the receiver RX 813 are operable to be communicatively connected to the device 820. The MEM 812 stores a program (PROG) 814. The PROG 814 may include instructions that enable the device 810 to operate according to an embodiment of the present disclosure (e.g., method 200) when executed on the associated processor 811. The combination of the at least one processor 811 and the at least one MEM 812 may form a processing device 815 suitable for implementing various embodiments of the present disclosure.

[0110] The device 820 includes at least one processor 811 (such as a DP) and at least one MEM 822 coupled to the processor 811. The device 820 may also include a suitable TX / RX 823 coupled to the processor 821, which may be operable to wirelessly communicate with the device 810. The MEM 822 stores a PROG 824. The PROG 824 may include instructions that, when executed on the associated processor 821, enable the device 820 to operate according to embodiments of the present disclosure, for example, to perform the method 400. The combination of the at least one processor 821 and the at least one MEM 822 may form a processing device 825 suitable for implementing various embodiments of the present disclosure.

[0111] Various embodiments of the present disclosure may be implemented by a computer program executable by one or more of the processors 811 , 821 , software, firmware, hardware, or a combination thereof.

[0112] MEMs 812 and 822 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.

[0113] Processors 811 and 821 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.

[0114] 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 disk 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.

[0115] The techniques described herein may be implemented by various means, so that the device for implementing one or more functions of the corresponding device described in the embodiments includes not only prior art devices, but also devices for implementing one or more functions of the corresponding device described in the embodiments, and it may include a separate device for each separate function, or may include a device 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.

[0116] 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 flowcharts and combinations of the blocks of the block diagrams and flowcharts can be implemented by various devices 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 a device for implementing the functions specified in the flowchart blocks.

[0117] 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 a particular embodiment that may be specific to a particular 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 the sub-combination.

[0118] 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 channel state information reference signal CSI-RS resource configuration from a network device, the CSI-RS resource configuration indicating a CSI-RS resource set, wherein the CSI-RS resource set includes a first CSI-RS resource group and a second CSI-RS resource group, the first CSI-RS resource group includes one or more first CSI-RS resources, and the second CSI-RS resource group includes one or more second CSI-RS resources, and the one or more first CSI-RS resources in the first CSI-RS resource group are different from the one or more second CSI-RS resources in the second CSI-RS resource group; as well as CSI measurement is performed based on a CSI-RS resource pair, wherein the CSI-RS resource pair includes a first CSI-RS resource among the one or more first CSI-RS resources and a second CSI-RS resource among the one or more second CSI-RS resources, and the resources in the CSI-RS resource pair are located in the same time slot or in consecutive time slots, and wherein the first CSI-RS resource in the CSI-RS resource pair is used for CSI-RS transmission through a first TRP, and the second CSI-RS resource in the CSI-RS resource pair is used for CSI-RS transmission through a second TRP. 2 . The method according to claim 1 , wherein two resources in the CSI-RS resource pair have different power ratios.

3. The method according to any one of claims 1 to 2, further comprising: Receiving at least two transmission configuration indications TCI from the network device; The performing CSI measurement further comprises: performing the CSI measurement using the CSI-RS resource pair having at least two quasi co-located QCL configurations indicated by the at least two TCIs.

4. The method according to any one of claims 1 to 3, wherein the CSI measurement is performed for multiple TRPs for multi-transmission reception point TRP transmission. 5 . The method according to claim 1 , wherein the CSI measurement is performed for a plurality of panels for a multi-panel transmission.

6. A method performed by a network device, comprising: transmitting a channel state information reference signal CSI-RS resource configuration to a terminal device, the CSI-RS resource configuration indicating a CSI-RS resource set, wherein the CSI-RS resource set includes a first CSI-RS resource group and a second CSI-RS resource group, the first CSI-RS resource group includes one or more first CSI-RS resources, and the second CSI-RS resource group includes one or more second CSI-RS resources, and the one or more first CSI-RS resources in the first CSI-RS resource group are different from the one or more second CSI-RS resources in the second CSI-RS resource group; and CSI-RS is transmitted using a CSI-RS resource pair, wherein the CSI-RS resource pair includes a first CSI-RS resource among the one or more first CSI-RS resources and a second CSI-RS resource among the one or more second CSI-RS resources, and the resources in the CSI-RS resource pair are located in the same time slot or in consecutive time slots, and wherein the first CSI-RS resource in the CSI-RS resource pair is used for CSI-RS transmission through a first TRP, and the second CSI-RS resource in the CSI-RS resource pair is used for CSI-RS transmission through a second TRP. The method according to claim 6 , wherein two of the CSI-RS resource pairs have different power ratios.

8. The method according to any one of claims 6 to 7, further comprising: Transmitting at least two transmission configuration indications TCI to the terminal device; and The transmitting of the CSI-RS further comprises: transmitting the CSI-RS using the CSI-RS resource pair having at least two quasi co-located QCL configurations indicated by the at least two TCIs.

9. The method according to any one of claims 6 to 8, wherein the CSI-RS is transmitted through multiple transmission reception point (TRP) transmissions.

10. The method according to any one of claims 6 to 9, wherein the CSI-RS is transmitted through a plurality of panels for multi-panel transmission.

11. 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 5.

12. A network device comprising: Transceiver; as well as A processor configured to execute or control the transceiver to execute the method according to any one of claims 6 to 10.

13. 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 5.

14. 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 6 to 10 when executed on the processor.

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