Joint CSI Feedback for DL Transmission Based on Multiple TRPs

Abstract

Methods and apparatuses for jointly reporting CSI in multi-TRP-based DL transmission are disclosed. In one embodiment, a method includes: sending a CSI report setting linked to two or more resource settings for channel measurement, wherein the two or more resource settings for channel measurement have the same number of CSI-RS resources, and receiving a joint CSI report corresponding to the CSI report setting.

Description

Technical Field

[0001] The subject matter disclosed herein generally relates to wireless communication, and more particularly, to methods and apparatuses for jointly reporting CSI for multi-TRP based DL transmission. Background Art

[0002] The following abbreviations are defined herein, at least some of which are referred to in the following description: 3rd Generation Partnership Project (3GPP), European Telecommunications Standards Institute (ETSI), Frequency Division Duplexing (FDD), Frequency Division Multiple Access (FDMA), Long Term Evolution (LTE), New Radio (NR), Very Large Scale Integration (VLSI), Random Access Memory (RAM), Read Only Memory (ROM), Erasable Programmable Read Only Memory (EPROM or Flash), Compact Disc Read Only Memory (CD-ROM), Local Area Network (LAN), Wide Area Network (WAN), Personal Digital Assistant (PDA), User Equipment (UE), Uplink (UL), Evolved Node B (eNB), Next Generation Node B (gNB), Downlink (DL), Central Processing Unit (CPU), Graphics Processing Unit (GPU), Field Programmable Gate Array (FPGA), Dynamic RAM (DRAM), Synchronous Dynamic RAM (SDRAM), Static RAM (SRAM), Liquid Crystal Display (LCD), Light Emitting Diode (LED), Organic LED (OLED), Orthogonal Frequency Division Multiplexing (OFDM), Radio Resource Control (RRC), Time Division Duplexing (TDD), Time Division Multiplexing (TDM), User Entity / Equipment (Mobile Terminal) (UE), Uplink (UL), Universal Mobile Telecommunications System (UMTS), Physical Downlink Shared Channel (PDSCH), Physical Uplink Shared Channel (PUSCH), Physical Uplink Control Channel (PUCCH), Downlink Control Information (DCI), Single DCI (S-DCI), Transmission and Reception Point (TRP), multi-TRP (multi-TRP or M-TRP), Quasi-Co-Location (QCL), Channel State Information (CSI), Channel State Information Reference Signal (CSI-RS), Transmission Configuration Indicator (TCI), Reference Signal (RS), Medium Access Control (MAC), Control Element (CE), Demodulation Reference Signal (DM-RS), Non-Coherent Joint Transmission (NCJT), Frequency Range (FR), CSI-RS Resource Indicator (CRI), Rank Indicator (RI), Precoding Matrix Indicator (PMI), Layer Indicator (LI), Channel Quality Indicator (CQI), Non-Zero Power (NZP), Information Element (IE).

[0003] In NR Release 15, the CSI feedback framework is designed for the single-TRP scenario. The Channel State Information Reference Signal (CSI-RS) is used to measure the DL channel. The UE receives CSI-RS resources to perform DL channel measurements and can report the measurement results to the gNB (base station). The CSI-ReportConfig IE configured by RRC signaling is the CSI reporting setting used to notify the UE of the quantities (parameters) to be reported, the resources to be measured, and the reporting manner.

[0004] In NR Release 15, the CSI-ReportConfig is linked to one resource setting for channel measurement. This one resource setting for channel measurement can have multiple resource sets, and each resource set can include one or more CSI-RS resources. One or more CSI-RS resource sets selected from the resource setting are linked to a CSI-ReportConfig. From the UE's perspective, the CSI-RS resources included in the linked CSI-RS resource sets will be received by the UE for channel measurement. For example, the aperiodic CSI report is triggered by DCI, specifically the non-zero 'CSI request' field of DCI. Each CSI request field value, which is called the trigger state, is associated with one or more CSI-ReportConfig configured by the higher layer parameter CSI AperiodicTriggerState.

[0005] The higher layer parameter reportQuantity included in the CSI-ReportConfig IE configures the UE with the CSI quantities (parameters) to be reported. The parameters can include but are not limited to the CSI-RS Resource Indicator (CRI), Rank Indicator (RI), Precoding Matrix Indicator (PMI), Layer Indicator (LI), and Channel Quality Indicator (CQI).

[0006] The CRI is used to indicate the CSI-RS resource to derive the corresponding CSI parameter. That is, the CRI is used to indicate one CSI-RS resource from the CSI-RS resources included in the linked CSI-RS resource sets in the resource setting.

[0007] The RI is used to indicate the maximum number of DL layers that can be supported for the received CSI-RS resource indicated by the CRI.

[0008] The PMI is used to indicate the best precoding matrix suitable for the received CSI-RS resource indicated by the CRI.

[0009] The LI indicates which column of the precoder matrix of the reported PMI corresponds to the strongest layer of the codeword corresponding to the maximum reported broadband CQI. If two broadband CQIs are reported and have equal values, the LI corresponds to the strongest layer of the first codeword.

[0010] The CQI is used to indicate how good or bad the communication channel quality is.

[0011] NR Release 16 supports single DCI (S-DCI)-based multi-TRP DL transmission. The DCI can schedule PDSCH transmissions sent from two TRPs using two different beams in FR2, where each TRP sends a part of the layer of the PDSCH transmission. This means that the UE can receive PDSCH transmissions simultaneously sent from two TRPs with two different beams in FR2.

[0012] According to the CSI feedback framework of NR Release 16, CSI-RS resources for channel measurement cannot be sent to the UE simultaneously with different beams. Additionally, inter-TRP coordination (e.g., coordination between two TRPs) can only be regarded as interference based on measurements of NZP CSI-RS resources with determined layers. In this case, the reported CSI does not match well with the non-coherent joint PDSCH transmissions of different TRPs.

[0013] Although multiple individual CSI reports for different TRPs can be achieved by triggering different CSI reporting settings, it may cause unnecessary measurement delays. In addition, reported CSI parameters such as RI and PMI may not be the best CSI for joint transmission because the 'interference' between TRPs is not well considered in the separately reported CSI.

[0014] The present invention discloses a method and device for jointly reporting CSI for multi-TRP-based DL transmission. Summary of the Invention

[0015] A method and device for jointly reporting CSI for multi-TRP-based DL transmission are disclosed.

[0016] In one embodiment, a method includes: sending a CSI reporting setting linked to two or more resource settings for channel measurement, where the two or more resource settings for channel measurement have the same number of CSI-RS resources, and receiving a joint CSI report corresponding to the CSI reporting setting.

[0017] In one embodiment, two resource settings for channel measurement include a first resource setting and a second resource setting, and each CSI-RS resource in the first resource setting is associated with a CSI-RS resource in the second resource setting. The joint CSI report includes an index CRI k (k >= 0), where CRI k corresponds to the (k + 1)-th configured CSI-RS resource in the first resource setting and the (k + 1)-th configured CSI-RS resource in the second resource setting.

[0018] In another embodiment, the joint CSI report includes a joint RI, where each value of the joint RI indicates the RI performed on the CSI-RS resources indicated by the reported CRI. The sum of the RIs is less than or equal to the value indicated by the configured RI limit in the CSI report setting. The joint CSI report may include two or more LIs, where the first LI indicates which column of the precoder matrix of the first reported PMI corresponds to the strongest layer, and the second LI indicates which column of the precoder matrix of the second reported PMI corresponds to the strongest layer.

[0019] If the transmission of the CSI-RS resources is aperiodic, the CSI-RS resources within two or more resource settings are configured with the same trigger offset.

[0020] In another embodiment, a remote unit includes: a receiver that receives a CSI report setting linked to two resource settings for channel measurement, where the two resource settings for channel measurement have the same number of CSI-RS resources; and a transmitter that transmits a joint CSI report corresponding to the CSI report setting.

[0021] In one embodiment, a method includes: receiving a CSI report setting linked to two resource settings for channel measurement, where the two resource settings for channel measurement have the same number of CSI-RS resources; and transmitting a joint CSI report corresponding to the CSI report setting.

[0022] In yet another embodiment, a base station unit includes: a transmitter that transmits a CSI report setting linked to two or more resource settings for channel measurement, where the two or more resource settings for channel measurement have the same number of CSI-RS resources; and a receiver that receives a joint CSI report corresponding to the CSI report setting. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] A more specific description of the embodiments briefly described above will be presented by reference to specific embodiments shown in the accompanying drawings. It should be understood that these drawings only depict some embodiments and should not be considered as limiting the scope. The embodiments will be described and explained with additional specificity and detail by using the drawings, in which:

[0024] Figure 1 shows a joint CSI report;

[0025] Figure 2 shows channel and interference measurements under multi-TRP (e.g., two TRPs) conditions;

[0026] Figure 3 is a schematic flowchart showing an embodiment of a method;

[0027] Figure 4is a schematic flowchart showing another embodiment of the method;

[0028] Figure 5 is a schematic block diagram showing a device according to an embodiment. Detailed implementation

[0029] Those skilled in the art will understand that certain aspects of the embodiments may be embodied as a system, a device, a method, or a program product. Accordingly, the embodiments may take the form of a complete hardware embodiment, a complete software embodiment (including firmware, resident software, microcode, etc.), or an embodiment combining software and hardware aspects, which are generally referred to herein as "circuits", "modules", or "systems". In addition, the embodiments may take the form of a program product embodied in one or more computer-readable storage devices storing machine-readable code, computer-readable code, and / or program code (hereinafter referred to as "code"). The storage device may be tangible, non-transitory, and / or non-transmissive. The storage device may not embody a signal. In a particular embodiment, the storage device only takes a signal for accessing the code.

[0030] Some functional units described in this specification may be marked as "modules" to more specifically emphasize their independent implementation. For example, a module may be implemented as a hardware circuit, including a custom very large scale integration (VLSI) circuit or a gate array, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. A module may also be implemented in a programmable hardware device such as a field programmable gate array, a programmable array logic, a programmable logic device, etc.

[0031] A module may also be implemented with code and / or software for execution by various types of processors. For example, the identified code module may include one or more physical or logical blocks of executable code, which may be organized, for example, as objects, programs, or functions. However, the executable files of the identified module do not need to be physically located together, but may include different instructions stored in different locations, which, when logically connected together, include the module and achieve the purpose of the module.

[0032] In fact, a code module may contain a single instruction or many instructions, and may even be distributed over multiple different code segments, different programs, and multiple memory devices. Similarly, the operation data herein may be identified and shown within a module, and may be embodied in any suitable form and organized within any suitable type of data structure. This operation data may be collected as a single data set, or may be distributed over different locations, including different computer-readable storage devices. In the case where a module or a part of a module is implemented in software, the software part is stored on one or more computer-readable storage devices.

[0033] Any combination of one or more computer-readable media can be utilized. The computer-readable media can be a computer-readable storage medium. The computer-readable storage medium can be a storage device that stores code. The storage device can be, by way of example and without limitation, an electronic, magnetic, optical, electromagnetic, infrared, holographic, micro-mechanical, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing.

[0034] A non-exhaustive list of more specific examples of storage devices will include the following: an electrical connection having one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer-readable storage medium can be any tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device.

[0035] The code for performing the operations of the embodiments can include any number of lines and can be written in any combination of one or more programming languages, including object-oriented programming languages such as Python, Ruby, Java, Smalltalk, C++, etc., and conventional procedural programming languages such as the "C" programming language, etc., and / or machine languages such as assembly language. The code can execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer, or entirely on the remote computer or server. In the last case, the remote computer can be connected to the user's computer through any type of network connection, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computer (e.g., through the Internet using an Internet service provider).

[0036] References throughout this specification to "one embodiment," "an embodiment," or similar language mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one implementation. Thus, unless otherwise explicitly specified, the appearances of the phrases "in one embodiment," "in an embodiment," and similar language throughout this specification can, but do not necessarily, all refer to the same embodiment, but rather to "one or more but not all embodiments." Unless otherwise explicitly specified, the terms "comprising," "including," "having," and variations thereof all mean "including but not limited to." Unless otherwise explicitly specified, a list of enumerated items does not imply that any or all of the items are mutually exclusive. Unless otherwise explicitly specified, the terms "a," "an," and "the" also refer to "one or more."

[0037] In addition, the features, structures, or characteristics of the various embodiments described may be combined in any suitable manner. In the following description, numerous specific details are provided, such as examples of programming, software modules, user selections, network transactions, database queries, database structures, hardware modules, hardware circuits, hardware chips, etc., to provide a thorough understanding of the embodiments. However, those skilled in the relevant art will recognize that the embodiments may be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring any aspects of the embodiments.

[0038] Aspects of different embodiments are described below with reference to schematic flowcharts and / or schematic block diagrams of methods, apparatuses, systems, and program products according to embodiments. It should be understood that each block of the schematic flowcharts and / or schematic block diagrams, and combinations of blocks in the schematic flowcharts and / or schematic block diagrams, can be implemented by code. This code can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine, such that the instructions executed via the processor of the computer or other programmable data processing device create means for implementing the functions specified in one or more blocks of the schematic flowchart and / or schematic block diagram.

[0039] The code can also be stored in a storage device, which can direct a computer, other programmable data processing device, or other device to operate in a particular manner, such that the instructions stored in the storage device produce an article of manufacture including instructions for implementing the functions specified in one or more blocks of the schematic flowchart and / or schematic block diagram.

[0040] The code can also be loaded onto a computer, other programmable data processing device, or other device, so as to cause a series of operational steps to be performed on the computer, other programmable device, or other device to produce a computer-implemented process, such that the code executed on the computer or other programmable device provides a process for implementing the functions specified in one or more blocks of the flow block diagram and / or block diagram.

[0041] The schematic flowcharts and / or schematic block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of apparatuses, systems, methods, and program products according to various embodiments. In this regard, each block in the schematic flowcharts and / or schematic block diagrams can represent a module, segment, or portion of code that includes one or more executable instructions for implementing the specified logical function.

[0042] It should also be noted that in some alternative embodiments, the functions labeled in the boxes may occur outside the order labeled in the figures. For example, depending on the functions involved, two consecutively shown boxes may be executed substantially simultaneously, or these boxes may sometimes be executed in the reverse order. Other steps and methods that are functionally, logically, or effectually equivalent to one or more blocks or portions thereof of the illustrated figures can be contemplated.

[0043] Although various arrow types and line styles may be employed in the flowcharts and / or block diagrams, it should be understood that they do not limit the scope of the corresponding embodiments. In fact, some arrows or other connectors can be used to merely indicate the logical flow of the illustrated embodiments. For example, an arrow can indicate a waiting or monitoring period of unspecified duration between the enumerated steps of the illustrated embodiments. It should also be noted that each block of the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented by a system based on dedicated hardware that performs the specified functions or actions, or a combination of dedicated hardware and code.

[0044] The description of the elements in each figure can refer to the elements of a series of figures. Similar numbers represent similar elements in all figures, including alternative embodiments of similar elements.

[0045] The UE can have the ability of simultaneous DL reception with different 'QCL-TypeD' in FR2. That is, in a multi-TRP (e.g., two TRP) scenario where the UE is served by multiple TRPs, the UE can simultaneously receive DL signals from multiple TRPs in FR2 with different spatial Rx parameters.

[0046] Traditionally, one CSI-ReportConfig can only be linked to one resource setting for channel measurement related to one TRP. Specifically, the triggering state (i.e., non-zero CSI request field value) (assuming the triggering state is associated with one CSI-ReportConfig) is associated with one or more CSI-RS resource sets in one resource setting. In other words, one CSI-ReportConfig can only be used to configure the UE to report the CSI parameters of one TRP. If the CSI parameters of multiple TRPs (e.g., two TRPs) are to be reported, multiple (e.g., two) different CSI-ReportConfigs should be triggered to the UE.

[0047] According to the present disclosure, for one CSI report, "CSI-ReportConfig" can be configured for the UE with two resource settings for channel measurement (e.g., the first resource setting for channel measurement (which can be abbreviated as "the first resource setting") and the second resource setting for channel measurement (which can be abbreviated as "the second resource setting")), where the UE has the ability to receive simultaneously with different 'QCL-TypeD' in FR2. That is, one CSI report setting 'CSI-ReportConfig' is linked to two resource settings for channel measurement (i.e., the first resource setting and the second resource setting). Each of the first resource setting and the second resource setting has the same number of CSI-RS resources. Each CSI-RS resource in the first resource setting has an associated CSI-RS resource in the second resource setting, which means that in a multi-TRP (e.g., two TRPs) scenario, two associated CSI-RS resources are sent simultaneously from two TRPs respectively. In each of the first resource setting and the second resource setting, the same number of resource sets are configured. For example, N (N>0) first resource sets are configured in the first resource setting; and the same number of N second resource sets are configured in the second resource setting. Each first resource set in the first resource setting has its associated second resource set in the second resource setting. The association between the first resource set and the second resource set means that (1) the number of CSI-RS resources in the first resource set is equal to the number of CSI-RS resources in its associated second resource set, and (2) based on the same sorting of the CSI-RS resources in each of the first resource set and its associated second resource set, each CSI-RS resource in the first resource set is associated with the CSI-RS resources in its associated second resource set one by one.

[0048] For example, the first resource setting includes N first resource sets, and the second resource setting includes the same number of N second resource sets. The nth (n = 1 to n) first resource set in the first resource setting is associated with the same nth second resource set in the second resource setting. In addition, based on the same sorting, each CSI-RS resource in the nth first resource set is associated with the CSI-RS resources in the associated nth second resource set one by one.

[0049] For aperiodic CSI reports, the trigger state associated with one CSI report setting 'CSI-ReportConfig' is associated with two resource settings for channel measurement. Specifically, the trigger state associated with one CSI report setting 'CSI-ReportConfig' is associated with one or more resource sets (first resource sets) in the first resource setting and the associated one or more resource sets (associated second resource sets) in the second resource setting.

[0050] Each of the first resource set and its associated second resource set includes the same number of CSI-RS resources. Additionally, the CSI-RS resources included in each first resource set and the CSI-RS resources included in its associated second resource set are associated one by one based on sorting. For example, the triggering state associated with a CSI reporting setting 'CSI-ReportConfig' is associated with M (M>0) first resource sets and their associated M second resource sets. Since the CSI-RS resources included in each of the first resource sets and the CSI-RS resources included in the associated second resource sets have the same number and are associated with each other, the CSI-RS resources in all the first resource sets linked to a CSI reporting setting 'CSI-ReportConfig' and the CSI-RS resources included in all the associated second resource sets linked to the same CSI reporting setting 'CSI-ReportConfig' have the same number and are associated with each other.

[0051] From the perspective of the UE, when a CSI reporting setting 'CSI-ReportConfig' is linked to one or more first resource sets in the first resource setting and the same number of second resource sets in the second resource setting, the UE will be configured to have one or more CSI-RS resources in all the first resource sets and the same number of CSI-RS resources in all the associated second resource sets. Additionally, one or more CSI-RS resources in all the first resource sets are associated one by one with the same number of CSI-RS resources in all the associated second resource sets. Therefore, for simplicity, one or more CSI-RS resources in all the first resource sets in the first resource setting linked to a CSI reporting setting 'CSI-ReportConfig' can be referred to as the CSI-RS of the "first resource set", and the same number of CSI-RS resources in all the second resource sets in the second resource setting linked to a CSI reporting setting 'CSI-ReportConfig' can be referred to as the CSI-RS resources of the "second resource set". Needless to say, based on the same sorting, the CSI-RS resources of the "first resource set" are associated one by one with the CSI-RS resources in the "second resource set".

[0052] Figure 1An example is shown. A CSI-RS resource set #1 (first resource set) containing 5 CSI-RS resources in a first resource configuration is linked to a 'CSI-ReportConfig'; a CSI-RS data set #2 (second resource set) containing the same number of 5 CSI-RS resources in a second resource configuration is linked to the same 'CSI-ReportConfig'. Each CSI-RS resource within the CSI-RS resource set #1 is associated with a CSI-RS within the CSI-RS resource set #2 in the same order. Specifically, CSI-RS resource #1-1 is associated with CSI-RS resource #2-1, CSI-RS resource #1-2 is associated with CSI-RS resource #2-2, CSI-RS resource #1-3 is associated with CSI-RS resource #2-3, CSI-RS resource #1-4 is associated with CSI-RS resource #2-4, and CSI-RS resource #1-5 is associated with CSI-RS resource #2-5.

[0053] When the transmission of the CSI-RS resource set is non-periodic, it is not desirable for the UE to be configured with different non-periodic triggering offsets for NZP CSI-RS between two CSI-RS (i.e., the first resource set and the second resource set). In the present disclosure, only the non-periodic triggering offset is configured for the first resource set, and the non-periodic triggering offset of the second resource set follows that of the first resource set.

[0054] In Figure 1 the example of, if the transmissions of CSI-RS resource set #1 and CSI-RS resource set #2 are non-periodic, they are configured to have the same aperiodicTriggeringOffset value.

[0055] In the prior art, since a CSI reporting setting 'CSI-ReportConfig' is linked to a CSI-RS resource set for a resource configuration related to channel measurement associated with one TRP, the UE only reports CSI parameters of one TRP.

[0056] In the present disclosure, a CSI reporting setting 'CSI-ReportConfig' is linked to CSI-RS resource sets for two resource configurations related to channel measurement associated with two TRPs, and the UE will report CSI parameters of two TRPs.

[0057] Similar to the prior art, the CSI parameters to be reported depend on the'reportQuantity' included in 'CSI-ReportConfig'. For example, when the'reportQuantity' in 'CSI-ReportConfig' is set to 'cri-RI-LI-PMI-CQI', the CRI, RI, PMI, LI, and CQI of both the first resource set related to the first TRP in the first resource setting and the second resource set related to the second TRP in the second resource setting will be reported. That is, CRI#1, RI#1, PMI#1, LI#1, and CQI#1, as well as CRI#2, RI#2, PMI#2, LI#2, and CQI#2 will be reported.

[0058] Obtain the CSI parameters CRI#1, RI#1, PMI#1, LI#1, and CQI#1 (CSI#1) for the first resource set related to TRP#1; and obtain the CSI parameters CRI#2, RI#2, PMI#2, LI#2, and CQI#2 (CSI#2) for the second resource set related to TRP#2.

[0059] When calculating RI (RI#1 and RI#2), PMI (PMI#1 and PMI#2), and LI (LI#1 and LI#2), QCL assumptions need to be considered.

[0060] According to the present disclosure, 'QCL-TypeD' (i.e., spatial Rx parameters) is indicated by the higher layer parameter qcl-info configured for the NZP CSI-RS resources used for channel measurement. This means that the UE uses the spatial Rx parameters indicated by the higher layer parameter qcl-info to receive the NZP CSI-RS resources used for channel measurement.

[0061] Specifically, calculate the first set of CSI parameters, such as RI#1, PMI#1, and LI#1, based on the qcl-info configured for the selected CSI-RS resources in the first resource setting. Calculate the second set of CSI parameters, such as RI#2, PMI#2, and LI#2, based on the qcl-info configured for the selected CSI-RS resources in the second resource setting.

[0062] In the DL transmission of multi-TRP (e.g., two TRPs) based on a single DCI, the UE can obtain the channel matrix from the TRP to the UE and can cancel the inter-TRP interference at the UE side. Therefore, when calculating the interference signal, the interference caused by the associated NZP CSI-RS resources used for channel measurement does not belong to the other interference for deriving the CSI parameters.

[0063] As Figure 2 shown, the gNB is based on the joint channel matrix H = [H 1,1,H 1,2 ,H 2,1 ,H 2,2 to schedule multi-TRP (two TRPs) PDSCH transmissions. H 1,1 Represents Tx beam #1 to be received by Rx beam #1 (i.e., the signal from TRP #1 to the UE). H 2,2 Represents Tx beam #2 to be received by Rx beam #2 (i.e., the signal from TRP #2 to the UE). On the other hand, H 1,2 Represents Tx beam #1 received by Rx beam #2 (i.e., the interference from TRP #1 to the signal to be received from TRP #2); H 2,1 Represents Tx beam #2 received by Rx beam #1 (i.e., the interference from TRP #2 to the signal to be received from TRP #1).

[0064] Interference between TRPs (between TRP #1 and TRP #2), i.e., corresponding to H 1,2 and H 2,1 The CSI can be estimated by the DM-RS sent from TRP #1 and TRP #2 and can be eliminated on the UE side (e.g., by an interference cancellation receiver). Therefore, when the UE calculates CSI parameters, the interference from the associated NZP CSI-RS resources (e.g., H 1,2 and H 2,1 ) for channel measurement should not be regarded as other interference signals on the REs of the NZP CSI-RS resources for channel measurement.

[0065] Take Figure 1 as an example. Suppose CSI-RS#1-3 in resource set #1 and its associated CSI-RS#2-3 in resource set #2 are indicated as the CRI to be reported. When calculating the CSI parameters of resource set #1 such as RI#1, PMI#1, CQI#1, and LI#1, the interference from the beams of CSI-RS#2-3 is not included as other interference. Similarly, when calculating the CSI parameters of resource set #2 such as RI#2, PMI#2, CQI#2, and LI#2, the interference from the beams of CSI-RS#1-3 is not included as other interference.

[0066] After obtaining the CSI parameters (e.g., CSI#1 and CSI#2) of the first and second resource sets, the UE will report these parameters. CSI#1 and CSI#2 can be reported separately. For example, two sets of {CRI, RI, PMI, LI, CQI} can be reported for the two resource sets.

[0067] Optionally (preferably), a joint CSI report for the two resource sets is possible. That is, CSI#1 and CSI#2 can be reported jointly.

[0068] (1) CRI:

[0069] Since the CSI-RS resources in the first resource set are associated with the CSI-RS resources in the second resource set one by one, a single CRI can be reported in the joint CSI report. As Figure 1 shown, if CRI#1-3 is selected in CSI#1 (correspondingly, CRI#2-3 is selected in CSI#2), only "CRI = 3" needs to be reported jointly, which means that both CRI#1-3 and CRI#2-3 are selected. The joint report of CRI can be reported with the exponential CRI k (k >= 0). For example, CRI 2 can be used to represent "CRI = 3". That is, CRI k (k >= 0) corresponds to the (k + 1)-th CSI-RS resource configured in the first resource set in the first resource setting and the (k + 1)-th CSI-RS resource configured in the second resource set in the second resource setting.

[0070] (2) RI:

[0071] RI#1 is calculated based on the CSI-RS resources indicated by the first CRI (e.g., CRI#1-3); and RI#2 is calculated based on the CSI-RS resources indicated by the second CRI (e.g., CRI#2-3). In the prior art, when RI#1 and RI#2 are reported separately, each of RI#1 and RI#2 is restricted by the higher layer parameter ri-Restriction, e.g., RI#1 <= ri-Restriction, RI#2 <= ri-Restriction. For example, when the higher layer parameter ri-Restriction is set to 4, each of RI#1 and RI#2 can take any value among 1, 2, 3, and 4. Therefore, reporting RI#1 requires two bits, and reporting RI#2 requires another two bits. Thus, reporting RI#1 and RI#2 requires four bits.

[0072] In the case of multiple TRPs (e.g., two TRPs), RI#1 and RI#2 can be reported jointly. The higher layer parameter ri-Restriction can be reinterpreted as the restriction on the sum of RI#1 and RI#2 (i.e., RI#1 + RI#2 <= ri-Restriction). Since there is an implicit restriction that at least one layer is sent from each TRP (i.e., RI#1 >= 1 and RI#2 >= 1), if ri-Restriction is set to 4, the possible combinations of the values of RI#1 and RI#2 can only be "1 and 1", "1 and 2", "2 and 1", "2 and 2", "1 and 3", "3 and 1". Therefore, the joint RI can be reported according to Table 1.

[0073] Table 1 Joint RI Indication

[0074] Combined RI indication value RI values (RI#1, RI#2) 0 1,1 1 1,2 2 2,1 3 2,2 4 1,3 5 3,1

[0075] It can be seen that the combined RI report only requires three bits (with only 6 possible values). Compared with the individual reports of RI#1 and RI#2, one bit can be saved.

[0076] (3) PMI

[0077] Based on the first CSI-RS resource indicated by the first CRI (e.g., CRI1#3) and the second CSI-RS resource indicated by the second CRI (e.g., CRI2#3), two PMIs (PMI#1 and PMI#2) are reported respectively for channel measurement.

[0078] (4) LI

[0079] Two LIs need to be reported. The first LI (LI#1) indicates which column of the precoder matrix of the first reported PMI (PMI#1) corresponds to the strongest layer, and the second LI (LI#2) indicates which column of the precoder matrix of the second reported PMI (PMI#2) corresponds to the strongest layer.

[0080] (5) CQI:

[0081] For single DCI-based multi-TRP non-coherent combined PDSCH transmission, only a single codeword can be scheduled. This means that a single TB size and a single MCS can be used for PDSCH transmission from multiple (e.g., two) TRPs. Therefore, it is preferable for the UE to report a single combined CQI obtained from CQI#1 and CQI#2. CQI#1 is calculated based on the first CSI-RS resource indicated by the first CRI (e.g., CRI1#3), and CQI#2 is calculated based on the second CSI-RS resource indicated by the second CRI (e.g., CRI2#3).

[0082] As an example of combined CSI reporting, Figure 1 The lower part of shows a UE configured with CSI-ReportConfig and reportQuantity set to 'cri-RI-LI-PMI-CQI'. The UE can report one CRI (e.g., CRI 2, i.e., "CRI = 3", which means CRI#1-3 and CRI#2-3), one combined RI (e.g., one of the values shown in Table 1, such as 2, 2), two PMIs (PMI#1 and PMI#2), two LIs (LI#1 and LI#2), and one CQI.

[0083] The above embodiments are described by way of examples of aperiodic CSI reporting. In addition, the transmission of CSI-RS resources (CSI-RS resource sets) is also described as aperiodic. The present invention applies to all types of CSI reporting, namely aperiodic, semi-persistent, and periodic. In addition, the transmission of CSI-RS resources (CSI-RS resource sets) can also be aperiodic, semi-persistent, and periodic. Specifically, when the transmission of CSI-RS resources is periodic, the CSI report can be aperiodic, semi-persistent, or periodic; when the transmission of CSI-RS resources is semi-persistent, the CSI report can be aperiodic or semi-persistent; and when the transmission of CSI-RS resources is aperiodic, the CSI report can be aperiodic. In any of the following cases, one 'CSI-ReportConfig' can configure two resource settings for channel measurement. Therefore, a joint CSI report can be sent from the UE to the gNB (base station).

[0084] The above embodiments are described by way of examples of two TRPs. The present invention also applies to multiple TRPs (more than two TRPs). In the case of multiple TRPs (e.g., more than two TRPs), for one CSI reporting setting 'CSI-ReportConfig', the same number of resource settings for channel measurement as the number of TRPs is configured for the UE. That is, one CSI reporting setting 'CSI-ReportConfig' is linked to multiple resource settings for channel measurement, where the number of resource settings for channel measurement is the same as the number of TRPs. Each resource setting for channel measurement linked to one CSI reporting setting 'CSI-ReportConfig' is associated with a different TRP. All resource settings for channel measurement can have the same number of CSI-RS resources. Each CSI-RS resource in one of the resource settings for channel measurement has an associated CSI-RS in each of the other resource settings for channel measurement. This means that the associated CSI-RS resources are transmitted simultaneously from different TRPs with different beams.

[0085] Figure 3 is a schematic flowchart showing an embodiment of method 300 according to the present application. In some embodiments, method 300 is performed by a device such as a remote unit. In certain embodiments, method 300 can be performed by a processor executing program code such as a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, an FPGA, etc.

[0086] Method 300 may include: 302 receiving a CSI report setting linked to two resource settings for channel measurement, wherein the two resource settings for channel measurement have the same number of CSI-RS resources; and 304 transmitting a joint CSI report corresponding to the CSI report setting.

[0087] Figure 4 FIG. 4 is a schematic flowchart showing an embodiment of method 400 according to the present application. In some embodiments, method 400 is performed by a device such as a base station unit. In certain embodiments, method 400 may be performed by a processor executing program code such as a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, an FPGA, etc.

[0088] Method 400 may include: 402 transmitting a CSI report setting linked to two or more resource settings for channel measurement, wherein the two or more resource settings for channel measurement have the same number of CSI-RS resources; and 404 receiving a joint CSI report corresponding to the CSI report setting.

[0089] Figure 5 FIG. 11 is a schematic block diagram showing a device according to an embodiment.

[0090] Referring to Figure 5 , the UE (i.e., the remote unit) includes a processor, a memory, and a transceiver. The processor implements Figure 3 the functions, processes, and / or methods proposed in Figure 4 . The gNB (i.e., the base station unit) includes a processor, a memory, and a transceiver. The processor implements

[0091] the functions, processes, and / or methods proposed in

[0092] In the above embodiments, the components and features of the embodiments are combined in a predetermined form. Unless otherwise clearly stated, each component or function should be regarded as an option. Each component or feature may be implemented without being associated with other components or features. In addition, an embodiment may be configured by associating some components and / or features. The order of operations described in the embodiments may be changed. Some components or features of any embodiment may be included in another embodiment or replaced with components and features corresponding to another embodiment. Obviously, claims not explicitly recited in the claims are combined to form an embodiment or included in a new claim.

[0093] Embodiments can be implemented by hardware, firmware, software, or a combination thereof. In the case of implementation by hardware, according to the hardware implementation, the exemplary embodiments described herein can be implemented by using one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, etc.

[0094] Embodiments can be practiced in other specific forms. The described embodiments are to be considered in all respects only illustrative and not restrictive. Thus, the scope of the present invention is indicated by the appended claims rather than by the foregoing description. All changes within the meaning and scope of the equivalents of the claims are to be included within their scope.

Claims

1. A method performed by a base station unit, comprising: Sending CSI report settings associated with two or more resource settings for channel measurement, wherein the two or more resource settings for channel measurement have the same number of CSI-RS resources, and Receiving a joint CSI report corresponding to the CSI report settings, Wherein the joint CSI report includes a joint RI, two PMIs, two LIs, and one CQI, and each value of the joint RI indicates an RI combination having a value of {1,1}, {1,2}, {2,1}, or {2,2}.

2. The method according to claim 1, wherein, The two resource settings for channel measurement include a first resource setting and a second resource setting, and each CSI-RS resource in the first resource setting is associated with a CSI-RS resource in the second resource setting.

3. The method according to claim 2, wherein, The joint CSI report includes an index CRIk, where k is an integer equal to or greater than 0, and wherein the CRI k corresponds to the (k + 1)th CSI-RS resource configured in the first resource setting and the (k + 1)th CSI-RS resource configured in the second resource setting.

4. The method according to claim 1, wherein, Each value of the joint RI indicates the RI performed by the CSI-RS resources indicated by the reported CRI.

5. The method according to claim 4, wherein The sum of the RIs is less than or equal to the value indicated by the RI limit configured in the CSI report settings.

6. The method according to claim 1, wherein, If the transmission of the CSI-RS resources is non-periodic, the CSI-RS resources within the two or more resource settings are configured with the same trigger offset.

7. The method according to claim 1, wherein, The first of the two LIs indicates which column of the precoder matrix of the first reported PMI corresponds to the strongest layer, and the second of the two LIs indicates which column of the precoder matrix of the second reported PMI corresponds to the strongest layer.

8. A method performed by a remote unit, comprising: Receiving CSI report settings linked to two or more resource settings for channel measurement, wherein the two or more resource settings for channel measurement have the same number of CSI-RS resources, and Sending a joint CSI report corresponding to the CSI report settings, Wherein the joint CSI report includes a joint RI, two PMIs, two LIs, and one CQI, and each value of the joint RI indicates an RI combination having a value of {1,1}, {1,2}, {2,1}, or {2,2}.

9. The method according to claim 8, wherein The two resource settings for channel measurement include a first resource setting and a second resource setting, and each CSI-RS resource in the first resource setting is associated with a CSI-RS resource in the second resource setting.

10. The method according to claim 9, wherein The joint CSI report includes an index CRIk, where k is an integer equal to or greater than 0, and wherein the CRI k corresponds to the (k + 1)th CSI-RS resource configured in the first resource setting and the (k + 1)th CSI-RS resource configured in the second resource setting.

11. The method according to claim 8, wherein, Each value of the joint RI indicates the RI performed by the CSI-RS resources indicated by the reported CRI.

12. The method according to claim 11, wherein, The sum of the RIs is less than or equal to the value indicated by the configured RI limit in the CSI report setting.

13. The method according to claim 8, wherein, If the transmission of the CSI-RS resources is non-periodic, the CSI-RS resources within the two or more resource settings are configured with the same triggering offset.

14. The method according to claim 8, wherein the first LI of the two LIs indicates which column of the precoder matrix of the first reported PMI corresponds to the strongest layer, and the second LI of the two LIs indicates which column of the precoder matrix of the second reported PMI corresponds to the strongest layer.

15. The method according to claim 8, wherein, The parameters of the joint CSI report are obtained by assuming interference, where the interference does not include the interference by the associated CSI-RS resources among the two or more resource settings for channel measurement.

16. A base station unit, comprising: a transmitter that transmits a CSI report setting linked to two or more resource settings for channel measurement, where the two or more resource settings for channel measurement have the same number of CSI-RS resources, and a receiver that receives a joint CSI report corresponding to the CSI report setting, where the joint CSI report includes a joint RI, two PMIs, two LIs, and a CQI, and each value of the joint RI indicates an RI combination having a value of {1,1}, {1,2}, {2,1}, or {2,2}.

17. The base station unit according to claim 16, wherein, The two resource settings for channel measurement include a first resource setting and a second resource setting, and each CSI-RS resource in the first resource setting is associated with a CSI-RS resource in the second resource setting.

18. The base station unit according to claim 17, wherein, The joint CSI report includes an index CRIk, where k is an integer equal to or greater than 0, and where the CRIk corresponds to the (k + 1)th configured CSI-RS resource in the first resource setting and the (k + 1)th configured CSI-RS resource in the second resource setting.

19. The base station unit according to claim 16, wherein Each value of the joint RI indicates the RI by the CSI-RS resources indicated by the reported CRI.

20. The base station unit according to claim 19, wherein, The sum of the RIs is less than or equal to the value indicated by the configured RI limit in the CSI report setting.

21. The base station unit according to claim 16, wherein, If the transmission of the CSI-RS resources is non-periodic, the CSI-RS resources within the two or more resource settings are configured with the same triggering offset.

22. The base station unit according to claim 16, wherein, The first LI of the two LIs indicates which column of the precoder matrix of the first reported PMI corresponds to the strongest layer, and the second LI of the two LIs indicates which column of the precoder matrix of the second reported PMI corresponds to the strongest layer.

23. A remote unit, comprising: a receiver that receives a CSI report setting linked to two or more resource settings for channel measurement, where the two or more resource settings for channel measurement have the same number of CSI-RS resources, and a transmitter that transmits a joint CSI report corresponding to the CSI report setting, where Among them, the joint CSI report includes a joint RI, two PMIs, two LIs, and one CQI. Each value of the joint RI indicates an RI combination with values of {1,1}, {1,2}, {2,1}, or {2,2}.

24. The remote unit according to claim 23, wherein, The two resource settings for channel measurement include a first resource setting and a second resource setting. Each CSI-RS resource in the first resource setting is associated with a CSI-RS resource in the second resource setting.

25. The remote unit according to claim 24, wherein, The joint CSI report includes an index CRIk, where k is an integer equal to or greater than 0, and where the CRIk corresponds to the (k + 1)th CSI-RS resource configured in the first resource setting and the (k + 1)th CSI-RS resource configured in the second resource setting.

26. The remote unit according to claim 23, wherein, Each value of the joint RI indicates the RI performed by the CSI-RS resources indicated by the reported CRI.

27. The remote unit according to claim 26, wherein, The sum of the RIs is less than or equal to the value indicated by the RI limit configured in the CSI report setting.

28. The remote unit according to claim 23, wherein, If the transmission of the CSI-RS resources is aperiodic, the CSI-RS resources within the two or more resource settings are configured with the same triggering offset.

29. The remote unit according to claim 23, wherein, The first LI of the two LIs indicates which column of the precoder matrix of the first reported PMI corresponds to the strongest layer, and the second LI of the two LIs indicates which column of the precoder matrix of the second reported PMI corresponds to the strongest layer.

30. The remote unit according to claim 23, wherein, The parameters of the joint CSI report are obtained by assuming interference, where the interference does not include the interference performed by the associated CSI-RS resources among the two or more resource settings for channel measurement.

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