Pre-compensation configuration

Abstract

Example embodiments of the present disclosure relate to a terminal device, a network device, methods, apparatuses and a computer readable storage medium for pre-compensation configuration for inter-TRP calibration. In this solution, first configuration may be provided to a terminal device, and accordingly the terminal device may perform pre-compensation of the CSI quantity for a first set of TRPs but not for a second set of TRPs. As such, the pre-compensation configuration can be flexible. For example, a condition such as workload at a TRP and a UE capability can be considered, and thus the pre-compensation will be more efficient.

Description

PRE-COMPENSATION CONFIGURATIONFIELD

[0001] This application claims priority from, and the benefit of, Finland Application No. 20245999, August 9, 2024, which is hereby incorporated by reference in its entirety.FIELD

[0002] Example embodiments of the present disclosure generally relate to the field of telecommunication and in particular, to a terminal device, a network device, methods, apparatuses and a computer readable storage medium for a pre-compensation configuration for inter-TRP calibration.BACKGROUND

[0003] The coherent joint transmission (CJT) offers downlink (DL) spectral efficiency and coverage gain. In the third generation partnership project (3GPP) release 18 (Rel-18 or R18), eType-ll channel state information (CSI) has been enhanced to accommodate CJT assuming ideal synchronization and backhaul. Scenarios such as inter-site CJT and a base station equipped with distributed remote radio heads (RRHs) require additional delay and phase / frequency calibration.SUMMARY

[0004] In general, example embodiments of the present disclosure provide a solution for a precompensation configuration for inter-TRP calibration.

[0005] In a first aspect, there is provided a terminal device. The terminal device comprises: at least one processor; and at least one memory storing instructions, wherein the instructions when executed by the at least one processor, cause the terminal device at least to: receive, from a network device, first configuration information indicating to the terminal device to perform a pre-compensation of a CSI quantity; and perform a pre-compensation of the CSI quantity for at least a first set of transmission and reception points (TRP) that is associated with the first configuration information, and refrain from performing a pre-compensation for a second set of TRPs that is not associated with the first configuration information.

[0006] I n a second aspect, there is provided a network device. The network device comprises: at least one processor; and at least one memory storing instructions, wherein the instructions when executed by the at least one processor, cause the network device at least to: determine first configuration information and second configuration information, wherein the first configuration information indicates that a precompensation of a CSI quantity is to be performed by a terminal device, and wherein the second configuration information indicates that a pre-compensation of a CSI quantity is not performed by the terminal device; and transmit, to the terminal device, the first configuration information indicating to the terminal device to perform a pre-compensation of a CSI quantity.

[0007] In a third aspect, there is provided a method. The method comprises: receiving, at a terminal device from a network device, first configuration information indicating to the terminal device to perform a precompensation of a CSI quantity; and performing a pre-compensation of the CSI quantity for at least a first set of TRPs that is associated with the first configuration information, and refrain from performing a precompensation for a second set of TRPs that is not associated with the first configuration information.

[0008] In a fourth aspect, there is provided a method. The method comprises: determining, at a network device, first configuration information and second configuration information, wherein the first configuration information indicates that a pre-compensation of a CSI quantity is to be performed by a terminal device, and wherein the second configuration information indicates that a pre-compensation of a CSI quantity is not performed by the terminal device; and transmitting, by the network device to the terminal device, the first configuration information indicating to the terminal device to perform a pre-compensation of a CSI quantity.

[0009] In a fifth aspect, there is provided an apparatus. The apparatus comprises: means for receiving, at a terminal device from a network device, first configuration information indicating to the terminal device to perform a pre-compensation of a CSI quantity; and means for performing a pre-compensation of the CSI quantity for at least a first set of TRPs that is associated with the first configuration information, and refrain from performing a pre-compensation for a second set of TRPs that is not associated with the first configuration information.

[0010] In a sixth aspect, there is provided an apparatus. The apparatus comprises: means for determining, at a network device, first configuration information and second configuration information, wherein the first configuration information indicates that a pre-compensation of a CSI quantity is to be performed by a terminal device, and wherein the second configuration information indicates that a pre-compensation of a CSI quantity is not performed by the terminal device; and means for transmitting, by the network device to the terminal device, the first configuration information indicating to the terminal device to perform a pre-compensation of a CSI quantity.

[0011] In a seventh aspect, there is an apparatus. The apparatus comprises: receiving circuitry configured to receive, at a terminal device from a network device, first configuration information indicating to the terminal device to perform a pre-compensation of a CSI quantity; and performing circuitry configured to perform a precompensation of the CSI quantity for at least a first set of TRPs that is associated with the first configuration information, and refrain from performing a pre-compensation for a second set of TRPs that is not associated with the first configuration information.

[0012] In an eighth aspect, there is an apparatus. The apparatus comprises: determining circuitry configured to determine, at a network device, first configuration information and second configuration information, wherein the first configuration information indicates that a pre-compensation of a CSI quantity is to be performed by a terminal device, and wherein the second configuration information indicates that a precompensation of a CSI quantity is not performed by the terminal device; and transmitting circuitry configuredto transmit, by the network device to the terminal device, the first configuration information indicating to the terminal device to perform a pre-compensation of a CSI quantity.

[0013] In a ninth aspect, there is provided a non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the method in a third or fourth aspect.

[0014] In a tenth aspect, there is provided a computer program comprising instructions, which, when executed by an apparatus, cause the apparatus at least the method in a third or fourth aspect.

[0015] It is to be understood that the summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Some example embodiments will now be described with reference to the accompanying drawings, in which:

[0017] FIG. 1A illustrates a CJT transmission with ideal backhaul based single- downlink control information (DCI) multi-TRP cooperation;

[0018] FIG. 1 B illustrates an example schematic of timing difference between two TRPs as measured by a UE;

[0019] FIG. 1 C illustrates an example schematic of a composite CJT channel delay profile exceeding the delay range resolvable by the precoding matrix indicator (PMI) frequency granularity;

[0020] FIG. 1 D illustrates an example schematic of channels measured on one port by one UE connected to 4 different TRPs in presence of TRP specific time alignment error (TAE);

[0021] FIG. 1 E illustrates an example schematic of UE throughput performance in presence of TAE;

[0022] FIG. 1 F illustrates an example of a network environment in which some example embodiments of the present disclosure may be implemented;

[0023] FIG. 2 illustrates an example of a process flow in accordance with some example embodiments of the present disclosure;

[0024] FIG. 3 illustrates an example use case for allowing hybrid configuration options for TAE compensation in accordance with some example embodiments of the present disclosure;

[0025] FIG. 4 illustrates a flowchart of a method implemented at a terminal device in accordance with some example embodiments of the present disclosure;

[0026] FIG. 5 illustrates a flowchart of a method implemented at a network device in accordance with some example embodiments of the present disclosure;

[0027] FIG. 6 illustrates a simplified block diagram of a device that is suitable for implementing some example embodiments of the present disclosure; and

[0028] FIG. 7 illustrates a block diagram of an example of a computer readable medium in accordancewith some example embodiments of the present disclosure.

[0029] Throughout the drawings, the same or similar reference numerals represent the same or similar elements.DETAILED DESCRIPTION

[0030] Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. The disclosure described herein can be implemented in various manners other than the ones described below.

[0031] In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

[0032] References in the present disclosure to “one embodiment,” “an embodiment,” “an example embodiment,” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0033] It shall be understood that although the terms “first” and “second” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and / or” includes any and all combinations of one or more of the listed terms.

[0034] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising”, “has”, “having”, “includes” and / or “including”, when used herein, specify the presence of stated features, elements, and / or components etc., but do not preclude the presence or addition of one or more other features, elements, components and / or combinations thereof. As used herein, “at least one of the following: ” and “at least one of ” and similar wording, where the list of two or more elements are joined by “and” or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

[0035] As used in this application, the term “circuitry” may refer to one or more or all of the following:(a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry) and(b) combinations of hardware circuits and software, such as (as applicable):(i) a combination of analog and / or digital hardware circuit(s) with software / firmware and(ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and(c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

[0036] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0037] As used herein, the term “communication network” refers to a network following any suitable communication standards, such as Long Term Evolution (LTE), LTE-Advanced (LTE-A), New Radio (NR), Wideband Code Division Multiple Access (WCDMA), High-Speed Packet Access (HSPA), Narrow Band Internet of Things (NB-loT) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (1G), the second generation (2G), 2.5G, 2.75G, the third generation (3G), the fourth generation (4G), 4.5G, the fifth generation (5G), the sixth generation (6G) communication protocols, and / or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

[0038] As used herein, the term “network device” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP), for example, a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), a new radio (NR) NB (also referred to as a gNB), a transmission and reception point (TRP), a Remote Radio Unit (RRU), a radio header (RH), a remote radio head (RRH), an integrated access and backhaul (IAB) node, a relay, a low power node such as a femto, a pico, and so forth, depending on theapplied terminology and technology.

[0039] The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE), a Subscriber Station (SS), a Portable Subscriber Station, a Mobile Station (MS), or an Access Terminal (AT). The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA), portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehiclemounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), USB dongles, smart devices, wireless customer-premises equipment (CPE), an Internet of Things (loT) device, a machine type communication (MTC) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. In the following description, the terms “terminal device”, “communication device”, “terminal”, “user equipment” and “UE” may be used interchangeably.

[0040] In the present disclosure, the terms “delay offset (DO)”, “time offset (TO)”, “time delay offset”, and “time alignment error (TAE)” may be used interchangeably in some cases, the terms “compensation”, “precompensation”, “TAE / DO / TO compensation”, “timing offset compensation”, “(pre-)compensation of CSI quantity”, and “pre-compensation of CSI-RS” may be used interchangeably in some cases, and the terms “report”, “CSI report”, “CSI feedback report”, and “PMI report” may be used interchangeably in some cases, unless otherwise indicated.

[0041] Rel-17 had introduced support for multi-TRP CSI reporting for the first time, with Type-I single panel (SP) for non-coherent joint transmission (NCJT) from two TRPs. In Rel-18 multiple-input multiple-output (MIMO) CSI enhancement, a new feature was introduced namely eType-ll-CJT, that extends support of eType-l I codebooks to multi-TRP CSI reporting for coherent joint transmission (CJT) with up to 4 distributed remote radio heads (RRH) or TRPs. CJT differs from NCJT in that it assumes that each MIMO layer can be transmitted from antenna ports of multiple TRPs, whereas in NCJT, each MIMO layer can only be transmitted from a single TRP.

[0042] Scenarios such as inter-site CJT and a base station equipped with distributed RRHs require additional delay and phase / frequency calibration. As the UE possesses more knowledge on DL channel condition in both frequency division duplex (FDD) and time division duplex (TDD), the need for inter-TRP calibration reporting measured from CSI-RS is evident not only to expand the deployment scenarios, but also to offer additional robustness to CJT operation. Therefore, one of objectives related to CJT enhancementwas proposed and agreed for Rel-19 as follows:• Specify UE reporting enhancement for CJT deployments under non-ideal synchronization and backhaul, targeting FR1 , both FDD and TDD• Inter-TRP time misalignment and frequency / phase offset measurement and reporting, assuming legacy CSI-RS design, with stand-alone aperiodic reporting on PUSCH.

[0043] In Rel-19 it was agreed that the UE would use tracking reference signal (TRS) resources from the different TRPs to measure the delay offset per TRP and report it as indicated in the agreement below.AgreementFor the Rel-19 aperiodic standalone CJT calibration reporting, the UCI parameters are captured in the tables below:• FFS: Mapping order• FFS: Whether it is possible not to report dn.• When ReportQuantity is ‘cjtc-Dd’ (Doffset+d)

[0044] It is proposed for the Rel-19 aperiodic standalone CJT calibration reporting, when ReportQuanti-ty is ‘cjtc-Dd’ (Doffset+d), support the following:- UE to compensate the delay offset for CSI-RS resources for CJT CSI re-porting (e.g. with Rel-18 Type-ll CJT codebook).- Link the report to the CJT CSI reporting (e.g. with Rel-18 Type-ll CJT codebook) so that the delay offset values for the transceiver compensation are aligned.

[0045] FIG. 1A illustrates a CJT transmission 110 with ideal backhaul based single-DCI multi-TRP cooperation. As illustrated, a multi-TRP system is formed by a maximum of NTRP= 4 cooperating TRPs (or TRP groups) connected via perfect backhaul link and transmitting coherently (CJT) to one or more coscheduled UEs.

[0046] It is assumed that all RRH / TRPs have the same array geometry, N x N2, with N antenna ports in azimuth and N2antenna ports in elevation, for each of the two polarisations, and 2N±N2antenna ports in total per TRP. In the example, each TRP is equipped with a 2x2 dual-polarised array, such that the total number of transmit antenna ports across the TRPs is 32.

[0047] In Type-ll-CJT a UE is configured to measure Ks= NTRPCSI-RS resources, one per TRP / TRP group, where NTRPis the maximum number of TRPs / TRP groups in the CJT cooperating set and it selects N < NTRPTRPS (or TRP groups) for CSI reporting. Hence, the CJT reporting set comprises a subset of the maximum CJT cooperating set configured by the gNB. In general, for the N selected TRPs, the Type-ll-CJTcodebook structure is given by formula (1) below:where Wl n(n = 1, ... , N) is a matrix with columns formed by the selected spatial-domain (SD) basis vectors, Wf n(n = 1, ... , N) is a matrix with columns formed by the selected frequency-domain (FD) basis vectors, and lV2 n(n = 1, N) is the matrix of combination coefficients.

[0048] The FD basis vectors are defined by a discrete Fourier transform (DFT) codebook, hence there is a correspondence between indices of the FD basis vectors and channel propagation delays. In fact, the delay domain is the definition domain of a discrete signal obtained by a DFT transformation of a signal measured in the frequency domain. Similarly, the SD basis vectors are defined by a DFT codebook, hence there is a correspondence between indices of the SD basis vectors and channel propagation angles of arrival.

[0049] The SD basis vectors are selected separately for each reported TRP. The FD basis vectors may be either selected jointly across TRPs, if codebook ‘mode-2’ is configured; or jointly across TRPs with a TRP specific phase shift, if codebook ‘mode-1’ is configured. Hence, with mode-2, a single set of FD basis vectors is used in the PMI representation for all TRPs, i.e., Wf= Wf l= ••• = Wf N. In both codebook modes, the number of selected FD basis vectors per TRP or across TRPs (i.e., the number of column vectors in Wfor in each of the matrices Wf l, Wf 2,is defined by a configuration parameter M.

[0050] Both NCJT and CJT operations may assume full overlap of MIMO layers in time and frequency resources, i.e., they both assume time synchronization between TRPs is within the cyclic prefix (CP) of a symbol. CJT also assumes phase synchronisation between TRPs such that precoding of a MIMO layer can be applied across antenna ports of multiple TRPs.

[0051] In the absence of the time synchronization, a performance loss is encountered in the CJT performance. The reason for that loss is that in Rel-18 eType II CSI, a common set of FD component basis Wf is assumed across all TRPs (as indicated above) and when there is a significant propagation delay between the different TRPs, but it is difficult to find a common delay window and the CSI is not captured correctly. Note that the larger the delay window, M, the higher UL overhead. Although mode-1 may account for an inter-TRP time delay offset, however the max time delay offset that can be resolved from mode-1 is not sufficient to resolve a delay up to cyclic prefix length.

[0052] In an inter-site CJT scenario, the cooperating TRPs are located in different cell sites. In this case, the receive timing difference between the signals transmitted from antenna ports of different TRPs can be considerable given the size of the CJT deployment, especially in the presence of a non-ideal backhaul. For example, the receive timing difference between the signals transmitted by antennas of two transmitting TRPs, at a UE, is the combination of a TRP relative time alignment error (TAE) and a radio frequency (RF)propagation delay difference, as shown in FIG. 1 B.

[0053] The time offsets arise from a time alignment error between TRPs tTAE, i.e. the hardware caused time offset is common for all UEs within a TRP, however, what the UE measures is the combined delay of propagation delay plus hardware caused time offset, which is represented by formula (2) below: tTRp = tTAE + prop (2) where the propagation delay tpropis specific for each UE-TRP channel, hence the final measured delay by the UE is specific for each UE-TRP channel.

[0054] The motivation for delay compensation is when the inter-TRP delay exceeds the delay range that can be resolved by the PMI calculation. If PMI is calculated with a frequency granularity of a subband, then 1 / subband is the maximum delay that can be resolved and any delay larger than this cause aliasing in the delay domain, resulting in a mismatch between the PMI and the actual composite CJT channel formed by the two TRPs.

[0055] FIG. 1 C illustrates an example schematic of a composite CJT channel delay profile 130 exceeding the delay range resolvable by the PMI frequency granularity. As illustrated, the aliasing occurs in the observed delay range, and thus a delay compensation for TRP 2 with respect to TRP 1 is needed for the precoder to match the actual composite CJT channel.

[0056] The TAE information may be fed back to the gNB, enables the gNB to apply the necessary compensation on the precoder weights before PDSCH transmission. However, prior to PMI calculation, if the channels from the different TRPs are not aligned, performance loss is encountered.

[0057] FIG. 1 D illustrates an example schematic of channels 140 measured on one port by one UE connected to 4 different TRPs in presence of TRP specific TAE. As illustrated, the UE cannot capture channels from TRP 1 and TRP 3 in one delay window without pre-alignment (or pre-compensation of the channels).

[0058] I n addition, if the step of CSI-RS pre-compensation is ignored, there would be a mismatch between the actual channel encountered by the PDSCH and the PMI available computed at the UE side. FIG. 1 E illustrates an example schematic of UE throughput performance 150 in presence of TAE. As illustrated, the performance loss due to the mismatch is shown by comparing the solid line 151 and the dashed line 152. Hence, the compensation of the effect of the inter-TRP delay offset prior to PMI computation is needed.

[0059] It is proposed to establish this linkage between the stand-alone-report indicating the estimated time alignment error between UE and gNB on one side and the PMI report on the other side. For example, which value should the UE use for pre-compensation prior to PMI computation and how to include this value is discussed.

[0060] Example embodiments of the present disclosure provide a solution for pre-compensation configuration for inter-TRP calibration. In this solution, first configuration may be provided to a terminal device, and accordingly the terminal device may perform pre-compensation of the CSI quantity for a first set of TRPsbut not for a second set of TRPs. As such, the pre-compensation configuration can be flexible. For example, a condition such as workload at a TRP and a UE capability can be considered, and thus the pre-compensation will be more efficient. Principles and some example embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0061] FIG. 1 F illustrates an example of a network environment 100 in which some example embodiments of the present disclosure may be implemented. The environment 100, which may be a part of a communication network, comprises a terminal device 102 and a network device 104.

[0062] The network device 104 may include a plurality of TRPs, such as NTRP TPRS, where NTRP is a positive integer. In some examples, the network device 104 may be regarded as a serving gNB of the plurality of TRPs. For example, the serving gNB may be one of the plurality of TRPs, or the serving gNB may be a gNB different from any of the NTRP TPRS.

[0063] The communication environment 100 may comprise any suitable number of devices and cells. In the communication environment 100, the network device 104 can provide services to the terminal device 102, and the network device 104 and the terminal device 102 may communicate data and control information with each other. In some embodiments, the network device 104 and the terminal device 102 may communicate with direct links / channels.

[0064] In the environment 100, a link from the network device 104 to the terminal device 102 is referred to as a downlink (DL), while a link from the terminal device 102 to the network device 104 is referred to as an uplink (UL). In downlink, the network device 104 is a transmitting (TX) device (or a transmitter) and the terminal device 102 is a receiving (RX) device (or a receiver). In uplink, the terminal device 102 is a transmitting TX device (or a transmitter) and the network device 104 is a RX device (or a receiver). It is to be understood that the network device 104 may provide one or more serving cells. In some embodiments, the network device 104 can provide multiple cells.

[0065] Communications in the network environment 100 may be implemented according to any proper communication protocol(s), comprising, but not limited to, cellular communication protocols of the first generation (1 G), the second generation (2G), the third generation (3G), the fourth generation (4G), the fifth generation (5G) and the sixth generation (6G) and the like, wireless local network communication protocols such as Institute for Electrical and Electronics Engineers (IEEE) 802.11 and the like, and / or any other protocols currently known or to be developed in the future. Moreover, the communication may utilize any proper wireless communication technology, comprising but not limited to: Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Frequency Division Duplex (FDD), Time Division Duplex (TDD), Multiple-Input Multiple-Output (MIMO), Orthogonal Frequency Division Multiple (OFDM), Discrete Fourier Transform spread OFDM (DFT-s-OFDM) and / or any other technologies currently known or to be developed in the future.

[0066] It is to be understood that the numbers of devices (i.e., the terminal device 102 and the networkdevice 104) and their connection relationships and types shown in FIG. 1 F are only for the purpose of illustration without suggesting any limitation. For example, the environment 100 may include any suitable numbers of devices adapted for implementing embodiments of the present disclosure. For example, while FIG. 1 F depicts the terminal device 102 as a mobile phone, the terminal device 102 may be any type of user equipment.

[0067] FIG. 2 illustrates an example of a process flow 200 in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the process flow 200 will be described with reference to FIG. 1 F. The process flow 200 involves a terminal device 102 and a network device 104. It would be appreciated that although the process flow 200 has been described in the network environment 100 of FIG. 1 F, this process flow may be likewise applied to other communication scenarios.

[0068] At 210, the network device 104 determine first configuration information and second configuration information for a pre-compensation configuration. In some implementations, the first configuration information may indicate that the pre-compensation should be performed at the terminal device 102, while the second configuration information may indicate that the pre-compensation will not be performed at the terminal device 102.

[0069] In the present disclosure, a hybrid configuration may be determined which may include two options: option 1 and option 2. In some examples, option 1 may indicate that the terminal device 102 performs the pre-compensation of CSI quantity. In some examples, option 2 may indicate that the terminal device 102 does not perform the pre-compensation of CSI quantity, for example, a gNB or TRP performs the precompensation of CSI quantity. It is allowed that the option 1 and option 2 may be simultaneously configurable for a given UE, i.e. some of the TRPs within the set of connected TRPs are connected with option 1 while the rest are connected with option2.

[0070] In some embodiments, the hybrid configuration can be adjusted dynamically, e.g., according to an actual condition, such as channel quantity, workload of TRP, etc.

[0071] At 220, the network device 104 transmits, and the terminal device 102 receives, the first configuration information, e.g., indicates that the terminal device 102 should perform a pre-compensation of CSI quantity for a first set of TRPs. In some implementations, the first configuration information may be included in a radio resource control (RRC) message or RRC signalling.

[0072] In some embodiments, the RRC message / signalling may further explicitly or implicitly indicates the first set of TRPs which is associated with the first configuration information. In some examples, the RRC message / signalling may include an indication of the first set of TRPs that associated with the first configuration information.

[0073] In some other examples, the RRC message / signalling may include an indication of a second set of TRPs that not associated with the first configuration information. In this case, the terminal device 102 may determine the first set of TRPs based on the RRC message / signalling, for example, the first set of TRPs maybe the rest TRPs other than the second set of TRPs; and thus the terminal determine 102 may be aware of which TRP(s) is / are associated with the first configuration information.

[0074] In some embodiments, the network device 104 may further transmit (not shown in FIG. 2) an indication triggering the first configuration for the first set of TRPs. In some examples, the triggering indication may be included in downlink control information (DCI) and / or a medium access control (MAC) control element (CE). In some examples, a two-step mechanism may be used. In some examples, the triggering indication may indicate the first set of TRPs that the first configuration information will apply.

[0075] In some examples, the DCI and / or the MAC-CE may include a bitmap with a plurality of bits, e.g., NTRP bits. For example, the plurality of bits may correspond to a plurality of TRPs respectively. If one bit is set as a first value, then a TRP corresponding to the bit with the first value may be regarded as one of the first set of TRPs. If another bit is set as a second value, then another TRP corresponding to the bit with the second value will not be regarded as one of the first set of TRPs, e.g., be one of a second set of TRPs. For instance, the first value is 1 (or 0) and the second value is 0 (or 1).

[0076] As such, the network device 104 may dynamically determine which TRP(s) can apply the first configuration information, and dynamically triggers the first configuration information for the determined TRP(s). Take a specific TRP as an examples, the specific TRP may be configured to be not associated with the first configuration information firstly, and the triggering indication in DCI / MAC-CE allows a switch the specific TRP to be associated with the first configuration information. For instance, a user load of the specific TRP may change, thus the pre-compensation for the specific TRP may change from option 1 to option 2, or vice versa, and then the network device 104 may use the triggering indication in DCI / MAC-CE to adapt the change.

[0077] In some embodiments of the present disclosure, multiple TRPs (such as NTRP TRPS, or selected N TRPs) may include or consist of the first set of TRPs and the second set of TRPs. I n case the first (or second) set of TRPs is indicated or determined, the terminal device 102 may also determine the second (or the first) set of TRPs. For example, the terminal device 102 may determine the first set of TRPs that applies the first configuration information.

[0078] At 230, the terminal device 102 performs the pre-compensation of CSI quantity for the first set of TRPs. The first set of TRPs may include one or more TRPs, and thus option 1 will be applied for each of the one or more TRPs.

[0079] The terminal device 102 will not perform the pre-compensation of CSI quantity for the second set of TRPs, that is, the terminal device 102 refrains from performing a pre-compensation for the second set of TRPs that is not associated with the first configuration information.

[0080] It should be understood that the pre-compensation at 230 is performed prior to PMI computation.

[0081] For any TRP in the first set of TRPs, such as TRP1 , the terminal device 102 may perform the precompensation of CSI quantity based on TAE information from the TRP1 or based on a pre-stored TAE value.In some embodiments, the first configuration information may further indicate to perform the precompensation of CSI quantity whether based on TAE information from the TRP or based on a pre-stored TAE value.

[0082] In some examples, for any TRP in the first set of TRPs, such as TRP1 , the terminal device 102 may receive TAE information from the TRP1 , and then the terminal device 102 may perform the precompensation of CSI quantity based on TAE information from the TRP1 . That is, the gNB or TRP makes its own decision on the value for pre-compensation, and provide it to the terminal device 102 through the TAE information.

[0083] In some examples, for any TRP in the first set of TRPs, such as TRP1 , the terminal device 102 may perform the pre-compensation of CSI quantity based on a pre-stored TAE value (i.e., a TAE value that is stored at the terminal device 102). For example, the pre-stored TAE value may be based on historical information, such as a previous report based on previous transmission of TRS / CSI-RS. In some examples, the terminal device 102 may transmit the pre-stored TAE value to the network device 104, as such, the network device 104 can be aware of the TAE value used for pre-compensation of CSI quantity. For instance, the pre-stored TAE value may be included in a PMI report from the terminal device 102 to the network device 104. As such, a linkage between the stand-alone report indicating the pre-stored TAE value and the PMI report can be established.

[0084] For any TRP in the first set of TRPs, such as TRP2, the TRP2 may perform the pre-compensation, e.g., prior to a transmission of CSI-RS to the terminal device 102. Since there is no need for the terminal device 102 to perform pre-compensation for TRP2, the UE complexity can be reduced. It is to be understood that the gNB / TRP may use any value of TAE for the pre-compensation, without notifying the terminal device 102, that is, it may depend on gNB implementation. In addition or alternatively, the TRP2 may transmit, to the terminal device 102, a UE specific CSI-RS after the pre-compensation by TRP2.

[0085] In addition or alternatively, the terminal device 102 may transmit a PMI report to the network device 104 at 240, e.g., after performing pre-compensation. Each TRP may transmit a CSI-RS to the terminal device 102, and accordingly a PMI report may be generated by the terminal device 102.

[0086] In the present disclosure, a UE specific CSI-RS or a UE group specific CSI-RS may be required, since the pre-compensation based on TAE is specific to the UE-TRP channel.

[0087] In some implementations, the first configuration information may be disabled for the first set of TRPs, e.g., after performing the pre-compensation of the CSI quantity for the first set of TRPs. In some implementations, the first configuration information may be enabled for a TRP (e.g., at least a TRP) in the second of TRPs, e.g., after performing the pre-compensation of the CSI quantity for the first set of TRPs. That is, option 1 and option 2 may be switched.

[0088] In some other implementations, option 1 or option 2 may be configured as a default option, and the first configuration information may be enabled or disabled according to the default option, e.g., afterperforming the pre-compensation of the CSI quantity for the first set of TRPs.

[0089] In some other implementations, the network device 104 may further transmit an instruction to the terminal device 102, for instructing the terminal device 102 to switch between options 1 and 2.

[0090] FIG. 3 illustrates an example use case for allowing hybrid configuration options for TAE compensation 300 in accordance with some example embodiments of the present disclosure. As illustrated, TRP 321 is densely populated and connected to several UEs including UE1-UE4 and UE 310; and TRP 322 is less populated.

[0091] In a case, UE 310 is served by both TRPs 321 and 322, e.g., in a CJT Rel-18 configuration. Due to lack of resources on TRP 321 , it can only receive cell-specific shared CSI-RS resources, and the UE 310 can be configured to perform pre-compensation for TRP 321 . TRP-2 can afford to allocate a UE specific CSI- RS resource for UE 310, and TRP 2 can decide to perform pre-compensation by itself (i.e. option 2), thereby reducing the processing requirements on UE 310 and reducing the amount of signaling needed between TRP 322 and UE 310.

[0092] In another case, the UE 310 may be firstly served by TRP 322 in a single TRP mode, and at a later stage UE 310 is served by both TRPs 321 and 322, e.g., the CJT configuration with TRP 321 is started. In this case, latency would be expected if TRP 321 would have to re-configure UE specific CSI-RS for UE 310. It is to be noted that in some scenarios, the UE 310 may have already been listening to the cell specific shared CSI-RS resource of TRP 321 before connecting to TRP 321 in CJT mode.

[0093] According to embodiments with reference to FIGS. 2-3, a solution for pre-compensation configuration is provided. The terminal device may be configured to perform the pre-compensation of CSI quantity for a first set of TRPs but not for a second set of TRPs. For the second set of TRPs, the precompensation may be performed by the TRP and the terminal device doesn’t need to do so. For example, a TRP in the second set of TRPs may transmit a UE-specific CSI-RS (which is already pre-compensated by the TRP) to the terminal device. In some examples, the terminal device may be configured to use a TAE value from a TRP or use a pre-stored TAE value for the pre-compensation. In some other examples, which TAE value is to be used for pre-compensation can be depend on UE implementation. For example, the TAE value used by the terminal device for compensation may be provided to the network device.

[0094] As such, a hybrid configuration may be used for CJT, and the performance loss can be mitigated. Specifically, UE-side compensation for some TRPs and gNB-side pre-compensation for other TPRs are combined, thereby optimizing resource use and ensuring accurate CSI quantity.

[0095] It should be noted that the process flow 200 is only one illustrative example without any limitation in the present disclosure, some other examples are also applied and the present disclosure does not limit for this aspect.

[0096] FIG. 4 illustrates a flowchart 400 of a method implemented at a terminal device in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 400 willbe described from the perspective of the terminal device 102 with reference to FIG. 1 F.

[0097] At block 410, the terminal device 102 receives, from a network device, first configuration information indicating to the terminal device to perform a pre-compensation of a CSI quantity. At block 420, the terminal device 102 performs a pre-compensation of a CSI quantity; and perform a pre-compensation of the CSI quantity for at least a first set of TRPs that is associated with the first configuration information, and refrains from performing a pre-compensation for a second set of TRPs that is not associated with the first configuration information.

[0098] In some example embodiments, the first configuration information is included in RRC signalling, wherein the RRC signalling comprises at least one of: an indication of the first set of TRPs associated with the first configuration information, or an indication of the second set of TRPs not associated with the first configuration information.

[0099] In some example embodiments, the terminal device receives, from a TRP in the first set of TRPs, TAE information to be used for pre-compensation; and performs the pre-compensation of CSI quantity based on the TAE information for the TRP.

[0100] In some example embodiments, the terminal device performs the pre-compensation of CSI quantity based on a pre-stored TAE value, where the pre-stored TAE value is included in a PMI report transmitted to the network device.

[0101] In some example embodiments, the terminal device disables the first configuration information after performing the pre-compensation of the CSI quantity for the first set of TRP. In some example embodiments, the terminal device enables the first configuration information for a second set of TRPs that is different from the first set of TRPs.

[0102] In some example embodiments, the terminal device transmits, to the network device, a PMI report after the pre-compensation of the CSI quantity.

[0103] In some example embodiments, the terminal device receives, from the network device, an indication triggering the first configuration information for the first set of TRPs. In some example embodiments, the indication is included in a DCI and / or a MAC-CE comprising a bitmap, wherein the bitmap comprises a plurality of bits corresponding to a plurality of TRPs respectively.

[0104] In some example embodiments, a bit with a first value indicates that a corresponding TRP applies the first configuration information, and another bit with a second value indicates that a corresponding TRP does not apply the first configuration information.

[0105] FIG. 5 illustrates a flowchart 500 of a method implemented at a network device in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 500 will be described from the perspective of the network device 104 with reference to FIG. 1 F.

[0106] At block 510, the network device 104 determines first configuration information and second configuration information, wherein the first configuration information indicates that a pre-compensation of aCSI quantity is to be performed by a terminal device, and wherein the second configuration information indicates that a pre-compensation of a CSI quantity is not performed by the terminal device. At block 520, the network device 104 transmits, to the terminal device, the first configuration information indicating to the terminal device to perform a pre-compensation of a CSI quantity.

[0107] In some example embodiments, the first configuration information is included in RRC signalling, wherein the RRC signalling comprises at least one of: an indication of the first set of TRPs associated with the first configuration information, or an indication of the second set of TRPs not associated with the first configuration information.

[0108] In some example embodiments, the network device instructs a TRP in a first set of TRPs associated with the first configuration information to provide TAE information to the terminal device; or transmits, to the terminal device, the TAE information associated with the TRP in the first set of TRPs. The TAE information is to be used by the terminal device for the pre-compensation of the CSI quantity for the TRP.

[0109] In some example embodiments, the network device receives, from the terminal device, a pre-stored TAE value which is used by the terminal device for the pre-compensation of the CSI quantity, wherein the pre-stored TAE value is included in a PMI report.

[0110] In some example embodiments, the network device instructs a TRP in a second set of TRPs not associated with the first configuration information to perform the pre-compensation of CSI quantity.

[0111] In some example embodiments, the network device disables the first configuration information after performing the pre-compensation of the CSI quantity for a first set of TRPs. In some example embodiments, the network device enables the first configuration information for a second set of TRPs that is different from the first set of TRPs.

[0112] In some example embodiments, the network device receives, from the terminal device, a PMI report after the pre-compensation of the CSI quantity.

[0113] In some example embodiments, the network device transmits, to the terminal device, an indication triggering the first configuration information for a first set of TRPs.

[0114] In some example embodiments, the indication is included in a DCI and / or a MAC-CE comprising a bitmap, wherein the bitmap comprises a plurality of bits corresponding to a plurality of TRPs respectively.

[0115] In some example embodiments, a bit with a first value indicates that a corresponding TRP applies the first configuration information, and another bit with a second value indicates that a corresponding TRP does not apply the first configuration information.

[0116] In some example embodiments, an apparatus (for example, the terminal device 102) comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive, from a network device, first configuration information indicating to the terminal device to perform a pre-compensation of a CSI quantity; and perform a precompensation of the CSI quantity for at least a first set of TRPs that is associated with the first configurationinformation, and refrain from performing a pre-compensation for a second set of TRPs that is not associated with the first configuration information.

[0117] In some example embodiments, the at least one memory storing instructions that, when executed by the at least one processor, further cause the apparatus to perform operations that discussed above that carried out by the terminal device 102.

[0118] In some example embodiments, an apparatus (for example, the network device 104) comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: determine first configuration information and second configuration information, wherein the first configuration information indicates that a pre-compensation of a CSI quantity is to be performed by a terminal device, and wherein the second configuration information indicates that a precompensation of a CSI quantity is not performed by the terminal device; and transmit, to the terminal device, the first configuration information indicating to the terminal device to perform a pre-compensation of a CSI quantity.

[0119] In some example embodiments, the at least one memory storing instructions that, when executed by the at least one processor, further cause the apparatus to perform operations that discussed above that carried out by the network device 104.

[0120] In some example embodiments, an apparatus capable of performing the method 400 (for example, the terminal device 102) may comprise means for performing the respective steps of the method 400. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

[0121] In some example embodiments, the apparatus comprises: means for receiving, at a terminal device from a network device, first configuration information indicating to the terminal device to perform a precompensation of a CSI quantity; and means for performing a pre-compensation of the CSI quantity for at least a first set of TRPs that is associated with the first configuration information, and refrain from performing a pre-compensation for a second set of TRPs that is not associated with the first configuration information.

[0122] In some example embodiments, the apparatus comprises means for performing various other operations carried out by the terminal device 102 as described above with reference to FIGS. 2-3.

[0123] In some example embodiments, an apparatus capable of performing the method 500 (for example, the network device 104) may comprise means for performing the respective steps of the method 500. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

[0124] In some example embodiments, the apparatus comprises: means for determining, at a network device, first configuration information and second configuration information, wherein the first configuration information indicates that a pre-compensation of a CSI quantity is to be performed by a terminal device, and wherein the second configuration information indicates that a pre-compensation of a CSI quantity is notperformed by the terminal device; and means for transmitting, by the network device to the terminal device, the first configuration information indicating to the terminal device to perform a pre-compensation of a CSI quantity.

[0125] In some example embodiments, the apparatus comprises means for performing various other operations carried out by the network device 104 as described above with reference to FIGS. 2-3.

[0126] FIG. 6 illustrates a simplified block diagram of a device 600 that is suitable for implementing some example embodiments of the present disclosure. The device 600 may be provided to implement the communication device, for example the terminal device 102, or the network device 104 as shown in FIG. 1 F. As shown, the device 600 includes one or more processors 610, one or more memories 620 coupled to the processor 610, and one or more communication modules 640 coupled to the processor 610.

[0127] The communication module 640 is for bidirectional communications. The communication module 640 has at least one antenna to facilitate communication. The communication interface may represent any interface that is necessary for communication with other network elements.

[0128] The processor 610 may be of any type suitable to the local technical network and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 600 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

[0129] The memory 620 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 624, an electrically programmable read only memory (EPROM), a flash memory, a hard disk, a compact disc (CD), a digital video disk (DVD), and other magnetic storage and / or optical storage. Examples of the volatile memories include, but are not limited to, a random access memory (RAM) 622 and other volatile memories that will not last in the power-down duration.

[0130] A computer program 630 includes computer executable instructions that are executed by the associated processor 610. The program 630 may be stored in the ROM 624. The processor 610 may perform any suitable actions and processing by loading the program 630 into the RAM 622.

[0131] The embodiments of the present disclosure may be implemented by means of the program 630 so that the device 600 may perform any process of the disclosure as discussed with reference to FIGS. 2-5. The embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

[0132] In some example embodiments, the program 630 may be tangibly contained in a computer readable medium which may be included in the device 600 (such as in the memory 620) or other storage devices that are accessible by the device 600. The device 600 may load the program 630 from the computer readable medium to the RAM 622 for execution. The computer readable medium may include any types of tangiblenon-volatile storage, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like.

[0133] FIG. 7 illustrates a block diagram of an example of a computer readable medium 700 in accordance with some example embodiments of the present disclosure. The computer readable medium 700 has the program 630 stored thereon. It is noted that although the computer readable medium 700 is depicted in form of CD or DVD in FIG. 7, the computer readable medium 700 may be in any other form suitable for carry or hold the program 630.

[0134] Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, apparatus, system, technique or method described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

[0135] The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computerexecutable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out the method as described above with reference to any of FIGS. 2-5. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

[0136] Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the processor or controller, cause the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

[0137] In the context of the present disclosure, the computer program codes or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable medium, andthe like.

[0138] The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. The term “non- transitory,” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM).

[0139] Further, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable subcombination.

[0140] Although the present disclosure has been described in languages specific to structural features and / or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

WHAT IS CLAIMED IS:1 . A terminal device comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the terminal device at least to: receive, from a network device, first configuration information indicating to the terminal device to perform a pre-compensation of a channel state information (CSI) quantity; and perform a pre-compensation of the CSI quantity for at least a first set of transmission and reception points (TRP) that is associated with the first configuration information, and refrain from performing a pre-compensation for a second set of TRPs that is not associated with the first configuration information.

2. The terminal device of claim 1 , wherein the first configuration information is included in radio resource control (RRC) signalling, wherein the RRC signalling comprises at least one of: an indication of the first set of TRPs associated with the first configuration information, or an indication of the second set of TRPs not associated with the first configuration information.

3. The terminal device of claim 1 or 2, wherein the at least one processor is configured to cause the terminal device to: receive, from a TRP in the first set of TRPs, time alignment error (TAE) information to be used for pre-compensation; and perform the pre-compensation of CSI quantity based on the TAE information for the TRP.

4. The terminal device of claim 1 or 2, wherein the at least one processor is configured to cause the terminal device to: perform the pre-compensation of CSI quantity based on a pre-stored TAE value; and wherein the pre-stored TAE value is included in a precoding matrix indicator (PMI) report transmitted to the network device.

5. The terminal device of any of claims 1-4, wherein the at least one processor is configured to cause the terminal device to: disable the first configuration information after performing the pre-compensation of the CSI quantity for the first set of TRPs; and / or enable the first configuration information for a second set of TRPs that is different from the first set of TRPs.

6. The terminal device of any of claims 1 -5, wherein at least one processor is configured to cause the terminal device to: transmit, to the network device, a precoding matrix indicator (PMI) report after the pre-compensation of the CSI quantity.

7. The terminal device of claim 1 , wherein the at least one processor is configured to cause the terminal device to: receive, from the network device, an indication triggering the first configuration information for the first set of TRPs.

8. The terminal device of claim 7, wherein the indication is included in downlink control information (DCI) and / or a medium access control (MAC) control element (CE) comprising a bitmap, wherein the bitmap comprises a plurality of bits corresponding to a plurality of TRPs respectively.

9. The terminal device of claim 8, wherein a bit with a first value indicates that a corresponding TRP applies the first configuration information, and another bit with a second value indicates that a corresponding TRP does not apply the first configuration information.

10. A network device comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the network device at least to: determine first configuration information and second configuration information, wherein the first configuration information indicates that a pre-compensation of a channel state information (CSI) quantity is to be performed by a terminal device, and wherein the second configuration information indicates that a pre-compensation of a CSI quantity is not performed by the terminal device; and transmit, to the terminal device, the first configuration information indicating to the terminal device to perform a pre-compensation of a CSI quantity.11 . The network device of claim 10, wherein the first configuration information is included in radio resource control (RRC) signalling, wherein the RRC signalling comprises at least one of: an indication of a first set of TRPs associated with the first configuration information, or an indication of a second set of TRPs not associated with the first configuration information.

12. The network device of claim 10, wherein the at least one processor is configured to cause the network device to: transmit, to the terminal device, an indication triggering the first configuration information for a first set of TRPs, wherein the indication is included in downlink control information (DCI) and / or a medium access control (MAC) control element (CE) comprising a bitmap, wherein the bitmap comprises a plurality of bits corresponding to a plurality of TRPs respectively.

13. A method comprising: receiving, at a terminal device and from a network device, first configuration information indicating to the terminal device to perform a pre-compensation of channel state information reference (CSI) quantity; and performing a pre-compensation of the CSI quantity for at least a first set of transmission and reception points (TRP) that is associated with the first configuration information, and refraining from performing a precompensation for a second set of TRPs that is not associated with the first configuration information.

14. A method comprising: determining, at a network device, first configuration information and second configuration information, wherein the first configuration information indicates that a pre-compensation of a channel state information (CSI) quantity is to be performed by a terminal device, and wherein the second configuration information indicates that a pre-compensation of a CSI quantity is not performed by the terminal device; and transmitting, by the network device and to a terminal device, the first configuration information indicating to the terminal device to perform a pre-compensation of a CSI quantity.

15. A non-transitory computer readable medium comprising program instructions that, when executed by an apparatus, cause the apparatus to perform at least the method of claim 13 or 14.

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