Terminal device, network device and method

Abstract

In one aspect, a terminal device schedules a PDSCH transmission in a CJT scheme, receives DCI indicating a set of TCI states, receives information on QCL parameter compensation for the PDSCH transmission, and receives the PDSCH transmission based on the set of TCI states and the information on QCL parameter compensation. In this way, PDSCH CJT can be supported within a unified TCI framework.

Description

[Technical Field]

[0001] FIELD Exemplary embodiments of the present disclosure relate generally to the field of telecommunications, and more particularly to an apparatus and method for communication in a unified transmission configuration indicator (TCI) framework. [Background technology]

[0002] As is well known, a unified TCI framework has been introduced to replace the TCI state or spatial relationship framework for beam direction. Recently, it has been proposed to support physical downlink shared channel (PDSCH) transmission in a coherent joint transmission (CJT) scheme. However, how to support PDSCH transmission in a CJT scheme within the unified TCI framework is still unclear and needs to be further studied. Summary of the Invention [Problem to be solved by the invention]

[0003] Overall, the exemplary embodiments of the present disclosure provide a method, apparatus, and computer storage medium for communication in a unified TCI framework. [Means for solving the problem]

[0004] In a first aspect, a terminal device is provided, the terminal device including a processor configured to cause the terminal device to receive downlink control information (DCI) for scheduling PDSCH transmission in a CJT scheme, the DCI indicating a set of TCI states, receive information of quasi co-location (QCL) parameter compensation for the PDSCH transmission, and receive the PDSCH transmission based on the set of TCI states and the information of the QCL parameter compensation.

[0005] In a second aspect, there is provided a terminal device including a processor configured to cause the terminal device to schedule a PDSCH transmission in a CJT manner, receive the DCI indicating a set of TCI states, and determine a TCI state from the set of TCI states to be used in a further transmission, wherein when the PDSCH transmission is performed in the CJT manner, the further transmission is not performed in the CJT manner.

[0006] In a third aspect, there is provided a method of communication, the method including: receiving, at a terminal device, the DCI that schedules a PDSCH transmission in a CJT scheme and indicates a set of TCI states; receiving information about QCL parameter compensation for the PDSCH transmission; and receiving the PDSCH transmission based on the set of TCI states and the information about QCL parameter compensation.

[0007] In a fourth aspect, there is provided a method of communication, the method including: receiving, at a terminal device, the DCI that schedules a PDSCH transmission in a CJT manner and indicates a set of TCI states; and determining a TCI state from the set of TCI states to be used in a further transmission, wherein when the PDSCH transmission is performed in the CJT manner, the further transmission is not performed in the CJT manner.

[0008] In a fifth aspect, there is provided a computer-readable medium storing instructions that, when executed on at least one processor, cause the at least one processor to perform a method according to the third or fourth aspect of the present disclosure.

[0009] It should be understood that this Summary of the Invention is not intended to identify key or essential features of the embodiments of the present disclosure, nor to limit the scope of the present disclosure. Other features of the present disclosure will be readily apparent from the following description. [Brief explanation of the drawings]

[0010] The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description of several embodiments of the present disclosure in the accompanying drawings.

[0011] [Figure 1] FIG. 1 illustrates an exemplary communication network in which embodiments of the present disclosure may be implemented.

[0012] [Figure 2A] FIG. 2 is a schematic diagram illustrating a problem in network compensation based on reported channel state information (CSI) for PDSCH transmission in a CJT scheme, in accordance with some example embodiments of the present disclosure;

[0013] [Figure 2B]FIG. 10 is a schematic diagram illustrating a problem in other transmissions when PDSCH transmission is performed in a CJT manner, according to some example embodiments of the present disclosure.

[0014] [Figure 3] FIG. 1 is a schematic diagram illustrating a communication process for configuring TCI for PDSCH transmission in a CJT scheme, in accordance with some example embodiments of the present disclosure.

[0015] [Figure 4] FIG. 2 is a schematic diagram illustrating a communication process for PDSCH transmission in a CJT scheme, in accordance with some example embodiments of the present disclosure.

[0016] [Figure 5A] FIG. 1 is a schematic diagram illustrating an example communication process using a TRS as a QCL reference, according to some example embodiments of the present disclosure.

[0017] [Figure 5B] FIG. 1 is a schematic diagram illustrating a communication process using a CSI-RS for channel measurement as a QCL reference, according to some example embodiments of the present disclosure.

[0018] [Figure 6] FIG. 1 is a schematic diagram illustrating a communication process for determining TCI for transmission without CJT, according to some example embodiments of the present disclosure.

[0019] [Figure 7] 1 is a flowchart illustrating an exemplary method performed by a terminal device, according to some embodiments of the present disclosure.

[0020] [Figure 8] 10 is a flowchart illustrating another exemplary method performed by a terminal device, according to some embodiments of the present disclosure.

[0021] [Figure 9]FIG. 1 is a schematic block diagram of an apparatus suitable for implementing embodiments of the present disclosure.

[0022] In the drawings, the same or similar reference numbers represent the same or similar elements. DETAILED DESCRIPTION OF THE INVENTION

[0023] The principles of the present disclosure will be described with reference to several embodiments. It should be understood that these embodiments are set forth for illustrative purposes only to aid those skilled in the art in understanding and practicing the present disclosure, and do not imply any limitations on the scope of the present disclosure. The present disclosure described in this disclosure can be implemented in various ways other than those described below.

[0024] In the following description and claims, unless defined otherwise, all technical and scientific terms used have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0025] As used herein, the term "terminal device" refers to any device with wireless or wired communication capabilities. Examples of terminal devices include user equipment (UE), personal computers, desktops, mobile phones, cellular phones, smartphones, personal digital assistants (PDAs), portable computers, tablets, wearable devices, Internet of Things (IoT) devices, Ultra-reliable and Low Latency Communication (URLLC) devices, Internet of Everything (IoE) devices, machine type communication (MTC) devices, in-vehicle devices for V2X communications where X stands for pedestrian, vehicle, or infrastructure / network, devices for Integrated Access and Backhaul (IAB), Small Data Transmission (SDT), mobility, Multicast and Broadcast Services (MBS), positioning, dynamic / flexible duplication in commercial networks, reduced capability (RedCap), High Altitude Platforms (HAP) including satellites and Unmanned Aircraft Systems (UAS). Satellite-based or airborne vehicles within a non-terrestrial network (NTN) including a satellite-based platform, extended reality (XR) devices including different types of reality such as augmented reality (AR), mixed reality (MR), and virtual reality (VR), and unmanned aerial vehicles (UAVs), which are aircraft without a human pilot and are commonly referred to as drones."Terminal Device" includes, but is not limited to, a mobile device (UE), a device on a high-speed train (HST), an image capture device such as a digital camera, a sensor game device, a music storage and playback device, or an internet device that enables wireless or wired internet access and browsing. A "terminal device" may also have "multicast / broadcast" capabilities to support public safety and mission-critical applications, V2X applications, transparent IPv4 / IPv6 multicast distribution, IPTV, smart TV, wireless services, over-the-air software distribution, group communication, and IoT applications. It may also incorporate one or more subscriber identity modules (SIMs), known as multi-SIMs. The term "terminal device" may be used interchangeably with UE, mobile station, subscriber station, mobile terminal, user terminal, or wireless device.

[0026] The term "network device" refers to a device capable of providing or hosting a cell or coverage area within which terminal devices can communicate. Examples of network devices include, but are not limited to, a Node B (Node B or NB), an evolved Node B (eNode B or eNB), a next generation Node B (gNB), a transmission reception point (TRP), a remote radio unit (RRU), a radio head (RH), a remote radio head (RRH), an IAB node, a low-power node such as a femto node or a pico node, a reconfigurable intelligent surface (RIS), a network-controlled repeater, etc.

[0027] A terminal device or a network device may have artificial intelligence (AI) or machine learning capabilities, which generally include a model trained from a large amount of data collected for a specific function and can be used to predict some information.

[0028] The terminal device or network device may operate on several frequency ranges, such as FR1 (410 MHz to 7125 MHz), FR2 (24.25 GHz to 71 GHz), frequency bands greater than 100 GHz, and Terahertz (THz). It can also operate on licensed, unlicensed, and shared spectrum. The terminal device may have two or more connections with the network device under a Multi-Radio Dual Connectivity (MR-DC) application scenario. The terminal device or network device can operate in full duplex, flexible duplex, and cross-division duplex modes.

[0029] The network device may have a function of network energy saving, self-organizing networks (SON) / minimization of drive tests (MDT). The terminal may have a function of power saving.

[0030] Embodiments of the present disclosure may be implemented in test equipment, such as, for example, a signal generator, a signal analyzer, a spectrum analyzer, a network analyzer, a test terminal device, a test network device, a channel emulator, and the like.

[0031] Embodiments of the present disclosure may be performed in accordance with any currently known or future developed generation of communication protocols, including, but not limited to, first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, fifth generation (5G) communication protocols, 5.5G, 5G-Advanced networks, or sixth generation (6G) networks.

[0032] In one embodiment, a terminal device may be connected to a first network device and a second network device. One of the first network device and the second network device may be a master node, and the other may be a secondary node. The first network device and the second network device may use different radio access technologies (RATs). In one embodiment, the first network device may be a first RAT device, and the second network device may be a second RAT device. In one embodiment, the first RAT device is an eNB, and the second RAT device is a gNB. Information regarding the different RATs may be transmitted to the terminal device from at least one of the first network device or the second network device. In one embodiment, the first information may be transmitted from the first network device to the terminal device, and the second information may be transmitted from the second network device directly or via the first network device to the terminal device. In one embodiment, information regarding the terminal device configuration configured by the second network device may be transmitted from the second network device via the first network device. The information regarding the reconfiguration of the terminal device configured by the second network device may be transmitted to the terminal device directly from the second network device or via the first network device.

[0033] As used herein, the singular forms "a," "an," and "said" include the plural forms unless the context clearly indicates otherwise. The term "comprises" and variations thereof should be understood as open-ended terms meaning "including, but not limited to." The term "based on" should be understood as "based at least in part on." The terms "one embodiment" and "embodiment" should be understood as "at least one embodiment." The term "another embodiment" should be understood as "at least one other embodiment." Terms such as "first," "second," etc. may refer to different or the same object. The following may include other explicit and implicit definitions.

[0034] In some instances, values, procedures, or devices are referred to as "best," "lowest," "highest," "minimum," "maximum," etc. It should be understood that such descriptions are intended to illustrate that selections may be made from among many functional alternatives used, and that such selections are not necessarily better, smaller, higher, or otherwise more preferred than other selections.

[0035] As mentioned above, it is still unclear how to support PDSCH transmission in the CJT method within the unified TCI framework. For example, it is unclear how PDSCH transmission in the CJT method will be performed within the unified TCI framework. It is also unclear how other transmissions will be performed when PDSCH transmission is performed in the CJT method.

[0036] In view of this, embodiments of the present disclosure provide a communication solution to overcome the above problems or other potential problems. In one solution, a terminal device schedules a PDSCH transmission in the CJT scheme, receives DCI indicating a set of TCI states, and receives information on QCL parameter compensation for the PDSCH transmission. Based on the set of TCI states and the information on QCL parameter compensation, the terminal device receives the PDSCH transmission. In this way, the PDSCH transmission in the CJT scheme can be correctly performed within a unified TCI framework.

[0037] In another solution, the terminal device schedules a PDSCH transmission in the CJT manner and receives DCI indicating a set of TCI states. The terminal device determines a TCI state from the set of TCI states to be used in a further transmission, and when the PDSCH transmission is performed in the CJT manner, the further transmission is not performed in the CJT manner. In this way, uplink and downlink transmissions in a unified TCI framework can be enhanced.

[0038] The principles and embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0039] In this disclosure, some terms may refer to the same or similar physical meaning and may be used interchangeably. Some illustrative examples are given below: The term "tracking reference signal (TRS)" may be used interchangeably with "NZP-CSI-RS-ResourceSet configured with the higher layer parameter trs-Info" or "CSI-RS resources in NZP-CSI-RS-ResourceSet configured with the higher layer parameter trs-Info". The term "CSI-RS for channel measurements" may be used interchangeably with "CSI-RS resources in the NZP-CSI-RS-ResourceSet that are configured without the higher layer parameter trs-Info and without the higher layer parameter repetition". The term "CSI-RS for beam measurement" may be used interchangeably with "CSI-RS resources in the NZP-CSI-RS-ResourceSet configured with higher layer parameter repetition". The term "QCL" may mean "Two antenna ports are said to be quasi-collocated if the large-scale characteristics of the channel through which symbols on one antenna port are transmitted can be inferred from the channel through which symbols on the other antenna port are transmitted. The large-scale characteristics include one or more of the following: delay spread, Doppler spread, Doppler shift, average gain, average delay, and spatial Rx parameters." The term “QCL ​​parameters” may mean that the large scale characteristics include one or more of delay spread, Doppler spread, Doppler shift, mean gain, mean delay, and spatial Rx parameters. The term “QCL ​​reference for PDSCH, PDCCH, CSI-RS” may mean “a quasi-co-location relationship between one or two downlink reference signals and a DM-RS port of PDSCH, a DM-RS port of PDCCH, or a CSI-RS port of CSI-RS resources.” The term "PDSCH CJT" may mean "PDSCH transmitted in the CJT mode." The term "PDCCH, PUCCH, PUSCH" may mean "PDCCH, PUCCH, PUSCH transmission when PDSCH is transmitted in the CJT mode." The term "DCI" may refer to "DCI format 1_1 / 1_2" or "DCI format 1_1 / 1_2 (with or without downlink (DL) allocation)". As DCI format 1_0 schedules common PDSCH in most cases and does not contain a TCI field, scheduled PDSCH may only be transmitted in s-TRP mode. The terms "precoder", "precoding", "precoding matrix", "beam", "spatial relationship information", "spatial relationship info", "precoding information", "precoding information and number of layers", "precoding matrix indicator (PMI)", "precoding matrix indicator", "transmit precoding matrix indication", "precoding matrix indication", "TCI state", "transmit configuration indicator", "quasi co-location (QCL)", "quasi co-location", "QCL parameters", "QCL assumption", "QCL relationship" and "spatial relationship" may be used interchangeably. The terms "single TRP", "single TCI state", "single TCI", "S-TCI", "single control resource set (CORESET)", "single CORESET pool", "s-TRP" and "S-TCI state" may be used interchangeably. The terms "multi-TRP", "multi-TCI state", "multi-CORESET", "multi-controlled resource set pool", "multi-TRP", "multi-TCI state", "multi-TCI", "multi-CORESET" and "multi-controlled resource set pool", "MTRP" and "M-TCI", "M-TRP" may be used interchangeably. The terms "resource", "resource within a resource set", and "resource set" may be used interchangeably. The terms "group", "subset" and "set" may be used interchangeably. The terms "transmit power", "energy per resource element (EPRE)", "linear average over the power contributions", and "average gain" may be used interchangeably. As used herein, the term "TRP" refers to an antenna array (having one or more antenna elements) available to a network device located at a particular geographic location. While some embodiments of the present disclosure have been described with reference to a multi-TRP scenario (or a single-TRP scenario) as an example, these embodiments are for illustrative purposes only and are intended to assist those skilled in the art in understanding and practicing the present disclosure, and do not imply any limitation on the scope of the present disclosure. It should be understood that the subject matter of the present disclosure described herein can be implemented in various ways different from those described below. As used herein, the term "network" / "network device" means one or more network devices. Thus, the terms "network," "network device," and "one or more network devices" may be used interchangeably. As used herein, QCL type may include the following types: - "typeA": {Doppler shift, Doppler spread, average delay, delay spread}, - "typeB": {Doppler shift, Doppler spread}, - "typeC": {Doppler shift, average delay}, - "typeD":{Spatial Rx parameters}.

[0040] Example of communication environment 1 illustrates an exemplary communication network 100 in which embodiments of the present disclosure can be implemented. The communication network 100 includes a network device 120 and a terminal device 110. The network device 120 may include TRPs 131-134 and may provide services to the terminal device 110 via any of the TRPs 131-134.

[0041] In the communication network 100, the link from the network device 120 to the terminal device 110 is called the downlink (DL), while the link from the terminal device 110 to the network device 120 is called the uplink (UL).

[0042] Furthermore, both single TRP mode transmission and MTRP transmission may be supported by the example of Figure 1. Specifically, in single TRP mode, the terminal device 110 communicates with the network device 120 via one of the TRPs 131-134. Alternatively, in MTRP mode, the terminal device 110 communicates with the network device 120 via two or more of the TRPs 131-134.

[0043] Communications in communication network 100 may conform to any suitable standard, including, but not limited to, Long Term Evolution (LTE), LTE-Evolution, LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), Code Division Multiple Access (CDMA), and Global System for Mobile Communications (GSM). Furthermore, communications may be performed according to any currently known or future-developed generation of communication protocols. Examples of communication protocols include, but are not limited to, first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, fifth generation (5G), 5.5G, 5G-Advanced networks, or sixth generation (6G) communication protocols.

[0044] It should be understood that the number of network devices, terminal devices, or TRPs in Figure 1 is given for illustrative purposes and does not imply any limitations on the present disclosure. Communications network 100 may include any appropriate number of network devices and / or terminal devices and / or TRPs suitable for implementing embodiments of the present disclosure.

[0045] In some embodiments, the terminal device 110 may monitor a set of PDCCH candidates in one or more CORESETs in an active DL bandwidth part (BWP) on each activated serving cell for which PDCCH monitoring is configured according to a corresponding search space set, where monitoring means receiving and decoding each PDCCH candidate according to the monitored DCI format.

[0046] In some embodiments, the network device 120 may transmit a DCI indicating a joint unified TCI state to the terminal device 110. The joint unified TCI state provides a reference signal for determining a QCL type and a QCL reference signal. For the UL, the unified TCI state further provides a transmit (TX) beam, an Uplink-power Control, and a path loss reference RS.

[0047] Recently, it has been agreed that a unified TCI framework extension may indicate up to two joint TCI states and apply to CJT-based PDSCH reception. It has also been agreed that PDSCH transmission in the CJT scheme may be supported. Specifically, up to four TRPs may be used for PDSCH transmission. PDSCH transmission is a single DCI-based MTRP scheme. Up to two joint TCI states may be indicated for PDSCH transmission. Other channels or signals, such as PDCCH, PUCCH, or PUSCH, do not use the CJT scheme.

[0048] In this case, it is unclear how up to two TCI states can be used to provide QCL information for four TRPs.

[0049] Furthermore, problems may occur with the QCL assumption. Figure 2A is a schematic diagram 200A illustrating a problem in network compensation based on reported CSI for PDSCH transmission in the CJT scheme, according to some example embodiments of the present disclosure. As shown in Figure 2A, a set of TCI states is configured or activated for a UE at timing T1. The UE may measure a set of TRSs and record large-scale characteristics at timing T2. Based on a set of CSI-RSs received from the network (NW) at timing T3, the UE may report CSI for the PDSCH CJT at timing T4. At timing T5, the UE may receive scheduling for the PDSCH CJT via a PDCCH. The scheduling may indicate one or more TCI states for the PDSCH CJT. The one or more TCI states indicated via the PDCCH are typically selected from the configured / activated TCI states. At timing T6, the UE receives the PDSCH CJT.

[0050] It can be seen that the network may perform compensation based on the reported CJT CSI, which may change the large-scale characteristics of the subsequent PDSCH CJT. If the UE only records those characteristics from the most recent measurement of the reference signal, there may be some discrepancies, which may degrade PDSCH demodulation performance. In the worst case, the PDSCH CJT may not be successful. In other words, if the UE is not aware of the network coordination, the UE may have an incorrect, outdated, or outdated QCL assumption.

[0051] More specifically, network compensation to support PDSCH CJT is to achieve fine-sync among multiple TRPs, e.g., to align the initial phase of the transmitted signal. It can be observed at the UE side that network compensation can cause changes in the time and / or frequency domain of the signal, changes in the delay and / or Doppler domain of the signal, and delay adjustment, phase rotation, Doppler shift, and frequency adjustment of the signal.

[0052] Furthermore, problems may occur in other transmissions that do not use the CJT scheme. Figure 2B is a schematic diagram 200B illustrating problems in other transmissions when PDSCH transmissions are performed using the CJT scheme, according to some example embodiments of the present disclosure. As shown in Figure 2B, at timing T7, the UE may receive scheduling for the PDSCH CJT via the PDCCH. The scheduling may indicate one or more TCI states for the PDSCH CJT. At timing T8, the UE may start applying the indicated one or more TCI states. However, the UE performs PDSCH reception from the network via TRP1, TRP2, TRP3, and TRP4. Furthermore, the UE performs PDCCH reception or PUCCH or PUSCH transmission via TRP1.

[0053] The unified TCI framework is designed for fast and low-overhead TCI updates of PDCCH / PDSCH / PUCCH / PUSCH. The joint TCI state can further provide UL power control parameters and path loss reference. However, only PDSCH can be transmitted in the CJT manner. Up to two TCI states can be mapped to one TCI codepoint in the DCI for PDSCH CJT. These TCI states may not provide adequate QCL and / or power control information for PDCCH / PUCCH / PUSCH and CSI-RS or SRS transmissions.

[0054] In view of the above, embodiments of the present disclosure provide communication solutions to overcome the above problems and other potential problems, which are described in detail below.

[0055] Example of TCI configuration for PDSCH CJT In this embodiment, a TCI configuration for PDSCH CJT is provided, which will be described in conjunction with FIG.

[0056] 3 is a schematic diagram illustrating a communication process 300 for configuring TCI for PDSCH CJT, according to some exemplary embodiments of the present disclosure. For purposes of explanation, the process 300 will be described with reference to FIG.

[0057] 3, terminal device 110 may transmit UE capability information to network device 120 (310). For example, network device 120 may transmit radio resource control (RRC) configuration related to the UE capability report to terminal device 110. Terminal device 110 may report the capabilities of terminal device 110 to network device 120 based on the RRC configuration. In some embodiments, the UE capability report may include information that the UE supports PDSCH transmission in the CJT scheme. It should be understood that any other suitable capability report is also possible.

[0058] Based on the UE capability report, the network device 120 may transmit 320 a configuration of the PDSCH CJT transmission scheme to the terminal device 110. In some embodiments, the network device 120 may transmit the configuration via an RRC message. Alternatively or additionally, the network device 120 may enable the PDSCH CJT using a medium access control element (MAC CE) or DCI.

[0059] In some embodiments, the configuration may include a list of TCI states. In some embodiments, the TCI states in the list may be joint TCI states. In some embodiments, the TCI states in the list may be DL TCI states. In some embodiments, the TCI states in the list may be UL TCI states.

[0060] In some embodiments, the configuration may be associated with a bandwidth part (BWP) or a component carrier (CC) or a band. In some embodiments, the configuration may be associated with a group of BWPs or CCs or bands. In some embodiments, the configuration may be associated with a TRP or a group of TRPs.

[0061] In some embodiments, the list of TCI states may include only one TCI state. In Example 1 for QCL configuration, the TRS may be configured as a QCL reference signal, e.g., qcl-Type1:TRS1, Type A. In Example 2 for QCL configuration, the CSI-RS (i.e., CSI-RS resource or resource set) for channel measurement may be configured as a QCL reference signal, e.g., qcl-Type1:CSI-RS Resource 1 / CSI-RS Resource Set 1, Type A. In Example 3 for QCL configuration, two or more TRS may be configured as QCL reference signals, e.g., qcl-Type1:TRS1, Type A and qcl-Type2:TRS2, Type B. In Example 4 for QCL configuration, two or more CSI-RS for channel measurement may be configured as QCL reference signals, e.g., qcl-Type1:CSI-RS Resource 1 / CSI-RS Resource Set 1, Type A and qcl-Type2:CSI-RS Resource 2 / CSI-RS Resource Set 2, Type B. For the above examples 2, 3 and 4, an additional UE capability report is needed to inform the network whether the UE can support such configurations.

[0062] In some embodiments where the list of TCI states may include only one TCI state, for an UL power control configuration, power control parameters may be configured for PUCCH, PUSCH, and SRS transmission for this TCI state, and a reference signal (e.g., CSI-RS configuration or synchronization signal (SS) block) identity (ID) may be configured for PUSCH path loss estimation for this TCI state.

[0063] In some embodiments, if no TCI state is configured, PDSCH CJT may also be supported in a UE-transparent manner. In some embodiments, if only one TCI state is configured, PDSCH CJT may be supported based on that one TCI state. In some embodiments, if only two TCI states are configured, PDSCH CJT may be supported based on these TCI states. In some embodiments, if more than two TCI states are configured, further selection, for example via MAC CE or DCI, may be required to indicate up to two TCI states to the UE.

[0064] In some embodiments, network device 120 may configure a set of CSI-RS resources and a CSI report for the PDSCH CJT. For example, the set of CSI-RS resources may include K_csi CSI-RS resources, e.g., K_csi≦M_trp, where M_trp represents the number of TRPs selected by terminal device 110 for CSI CJT. In some examples, M_trp≦N_trp, where N_trp represents the number of TRPs used for CSI CJT reporting. The selection of M_trp from N_trp may be reported using a bitmap with length N_trp. In some examples, K_csi=N_trp.

[0065] In some embodiments, network device 120 may configure a set of TRSs. For example, the set of TRSs may include M_trs TRSs, where M_trs≦N_trp, where N_trp represents the number of TRPs used for CSI CJT reporting. Each of the M_trs TRSs may be transmitted from a respective TRP. Terminal device 110 may measure each TRS and obtain a set of QCL parameters for each TRP. In some examples, M_trs=1, and multiple TRPs are transmitted collectively, transparent to terminal device 110. Terminal device 110 may measure this TRS and obtain QCL parameters for an equivalent transmission point or a virtual transmission point. In some examples, one of the TRSs may be a reference TRS and transmitted from the reference TRP.

[0066] Optionally, the network device 120 may set the number and / or maximum number of TCI states that can be mapped to one TCI code point, e.g., {1,2} or {1,2,3,4}, based on, e.g., a UE capability report. In some embodiments, the number and / or maximum number of TCI states may be less than or equal to the number of K_csi CSI-RS resources for CJT CSI reporting or the number of N_trp={1,2,3,4} coordinated TRPs for CJT CSI reporting.

[0067] In some embodiments, the number and / or maximum number of TCI states that can be mapped to one TCI code point may be configured separately for each cell / BWP in which the PDSCH CJT is configured. In some embodiments, the number and / or maximum number of TCI states that can be mapped to one TCI code point may be configured to be the same for each cell / BWP in which the PDSCH CJT is configured. In some embodiments, the number and / or maximum number of TCI states that can be mapped to one TCI code point may be configured separately for each configured CORESET. In some embodiments, the number and / or maximum number of TCI states that can be mapped to one TCI code point may be configured to be the same for each configured CORESET except for CORESET 0.

[0068] 3, network device 120 may send 330 a MAC CE to terminal device 110 that activates a subset of the TCI states in the list of TCI states. The MAC CE may further provide a mapping between the TCI states and the TCI codepoints in the DCI.

[0069] In some embodiments, the TRS corresponding to an activated TCI state may be considered activated. In some embodiments, if one TCI state is mapped to a TCI codepoint in the DCI for the PDSCH CJT, the terminal device 110 may measure the DL RS of this TCI state and obtain QCL parameters for an equivalent or virtual transmission point.

[0070] In some embodiments, two TCI states may be mapped to one TCI code point in the DCI for PDSCH transmission, where the first TCI state may provide reference information for the PDSCH transmission and the second TCI state may provide additional information for the PDSCH transmission that is different from the reference information.

[0071] In some embodiments, the additional information may include at least one of an average delay, a delay spread, a Doppler shift, a Doppler spread, a phase parameter, or a transmit power parameter. In some embodiments, the average delay may include a maximum average delay of the PDSCH transmission. In some embodiments, the delay spread may include a maximum delay spread of the PDSCH transmission. In some embodiments, the phase parameter may include an absolute phase, an initial phase, a phase shift, or a phase rotation. In some embodiments, the transmit power parameter may include a transmit power or a power offset.

[0072] In some embodiments, the DL RSs in the two TCI states may be configured or transmitted with the same transmit power or the same power offset relative to a reference transmit power, e.g., they may be configured to have the same parameter powerControlOffsetSS value.

[0073] In some embodiments, two TCI states may provide two different values ​​for a parameter, and the terminal device may assume that the applied value of the parameter is the maximum, minimum, average, or weighted average of the two values. For example, a first TCI state is associated with a first delay, and a second TCI state is associated with a second delay. In this case, the terminal device 110 may assume that the delay applied for the PDSCH CJT is the maximum value, or the first and second delays. In another example, a first TCI state is associated with a first Doppler, and a second TCI state is associated with a second Doppler. In this case, the terminal device 110 may assume that the Doppler applied for the PDSCH CJT is the average value, or the first and second delays. Furthermore, the terminal device 110 may assume that the applied value of the parameter is the value associated with the first TCI state or the second TCI state.

[0074] In some alternative embodiments, if one TCI state can provide two QCL reference signals, two TCI states can provide four QCL reference signals. For example, TCI state 1 provides qcl-Type1: TRS 1 or CSI-RS resource 1, Type A, and qcl-Type2: TRS 2 or CSI-RS resource 2, Types A / B / C. TCI state 2 provides qcl-Type1: TRS 3 or CSI-RS resource 3, Type A, and qcl-Type2: TRS 4 or CSI-RS resource 4, Types A / B / C.

[0075] Process 300 allows up to two TCI states to be used to provide QCL information for four TRPs so that the correct QCL assumption can be provided to the terminal device.

[0076] Implementation of PDSCH CJT within the Unified TCI Framework In this embodiment, a solution for PDSCH transmission in the CJT scheme is provided, which will be explained in relation to FIG.

[0077] 4 is a schematic diagram illustrating a communication process 400 for PDSCH transmission in a CJT scheme, according to some exemplary embodiments of the present disclosure. For purposes of explanation, the process 400 will be described with reference to FIG.

[0078] As shown in FIG. 4, terminal device 110 may report its capabilities to network device 120 (410). In some embodiments, the capabilities of terminal device 110 may include information on support for QCL parameter compensation. For example, the capabilities of terminal device 110 may include an indication of whether terminal device 110 can support compensation for one or more QCL parameters. In another example, the capabilities of terminal device 110 may include information on a range of QCL parameter compensation that terminal device 110 can support. In another example, the capabilities of terminal device 110 may include an indication of whether terminal device 110 can support demodulating PDSCH CJT using only the indicated TCI state (i.e., old QCL parameters).

[0079] In some embodiments, the capabilities of the terminal device 110 may include a duration of QCL parameter compensation. For example, the capabilities of the terminal device 110 may include a duration during which the terminal device 110 can acquire new QCL parameters based on the QCL parameter compensation. In another example, the capabilities of the terminal device 110 may include a duration during which the terminal device 110 can apply QCL parameter compensation. In yet another example, the capabilities of the terminal device 110 may include a duration during which the terminal device 110 can apply the indicated TCI state together with QCL parameter compensation. It should be understood that any combination of the above information is also possible.

[0080] Continuing with reference to FIG. 4, the network device 120 may transmit 420 a reference signal (also referred to herein as a first reference signal for convenience) as a QCL reference. In some embodiments, the first reference signal may be explicitly set as a QCL reference in the TCI state. In some embodiments, the first reference signal may be implicitly determined. In some embodiments, the first reference signal may be a TRS. In some embodiments, the first reference signal may be a CSI-RS for channel measurements.

[0081] 4, the network device 120 may transmit 430 CSI-RS for channel or interference measurement to the terminal device 110. In an example, K_csi CSI-RS may be transmitted from N_trp TRPs. In another example, one CSI-RS may be repeatedly transmitted from N_trp TRPs.

[0082] Based on the measurements on the CSI-RS, the terminal device 110 may report CSI for the PDSCH CJT to the network device 120 (440). For example, a Type-II codebook and its refinements may be reported. In another example, a strongest coefficient indicator (SCI) may be reported. The SCI may be applied across all N CSI-RS resources and used to determine a reference TRP. In yet another example, a selection of M_trp CSI-RS resources from the K_csi CSI-RS resources or N_trp TRP may be reported. If M_trp = N_trp is configured as a limit by the network, the selection of M_trp CSI-RS resources may not be reported.

[0083] Based on the reported CSI, the network device 120 may perform adjustments to the PDSCH CJT (450). For example, the network device 120 may determine the number of TRPs to be used for the PDSCH CJT and perform fine synchronization between the TRPs to adjust signals coherently transmitted from different TRPs. The compensation may be an adjustment method for the time domain and / or the frequency domain. The compensation may be an adjustment method for one or more of the average delay, delay spread, Doppler shift, and Doppler spread (in other words, QCL Type A / B / C / D parameters). The compensation may be an adjustment method for one or more of the phase shift and the frequency shift. The compensation may be an adjustment method for the transmit power. It should be understood that these are merely examples and that the network adjustments may depend on the network implementation.

[0084] Continuing with reference to FIG. 4, network device 120 may transmit 460 a DCI via the PDCCH scheduling the PDSCH CJT. The DCI indicates a set of TCI states. In some embodiments, the DCI may include a TCI field that informs terminal device 110 of a QCL assumption for PDSCH reception. The TCI field may include the number of TRPs for the PDSCH CJT. It should be understood that the TCI field is optional.

[0085] 4, network device 120 may transmit information on QCL parameter compensation for PDSCH CJT to terminal device 110 (470). In some embodiments, network device 120 may include the information on QCL parameter compensation in DCI. In this case, terminal device 110 may obtain the information on QCL parameter compensation from the DCI. It should be understood that the information on QCL parameter compensation may be transmitted separately from the DCI.

[0086] In some embodiments, the QCL parameter compensation information may include compensation for a time-domain parameter. In some embodiments, the QCL parameter compensation information may include compensation for a frequency-domain parameter, such as a frequency value or a frequency shift. In some embodiments, the QCL parameter compensation information may include compensation for a phase parameter, such as a phase value or a phase shift. In some embodiments, the QCL parameter compensation information may include compensation for a delay parameter, such as a mean delay or a delay spread. In some embodiments, the QCL parameter compensation information may include compensation for a Doppler parameter, such as a Doppler shift or a Doppler spread. In some embodiments, the QCL parameter compensation information may include compensation for transmit power.

[0087] In some embodiments, the QCL parameter compensation information may include an indication of whether QCL parameter compensation has been applied. In some embodiments, the indication may include the exact value of the compensation applied. For example, for a delay parameter, the indication may include X μs. For a Doppler parameter, the indication may include X Hz. For a phase parameter, the indication may include X degrees. For a power parameter, the indication may include X dB. In some embodiments, the indication may be signaled for each TCI state. In some embodiments, the reference TRP may not require any compensation to be applied.

[0088] In some embodiments where two TCI states are mapped to one TCI codepoint in the DCI, information for QCL parameter compensation may be provided via the second TCI state.

[0089] Based on the set of TCI states and the information about the QCL parameter compensation, terminal device 110 may receive 480 the PDSCH CJT.

[0090] In some embodiments, terminal device 110 may receive a first set of reference signals based on a set of TCI states and determine a set of QCL parameters (also referred to herein as a first set of QCL parameters for convenience) based on measurements on the first set of reference signals (also referred to herein as first measurements for convenience) (481). Terminal device 110 may then receive a PDSCH CJT based on the first set of QCL parameters and QCL parameter compensation information (481'). In some embodiments, terminal device 110 may determine another set of QCL parameters (also referred to herein as a second set of QCL parameters for convenience) by modifying the first set of QCL parameters based on the QCL parameter compensation information (482), and receive a PDSCH transmission based on the second set of QCL parameters (482'). For example, if detailed values ​​have already been indicated as QCL parameter compensation information, terminal device 110 may apply those values, for example, scaled or offset, to previous measurements on the first reference signals (i.e., first measurements). Thus, the QCL parameters may be adjusted based on previous measurements.

[0091] Alternatively, terminal device 110 may ignore previous measurements and update the set of QCL parameters using additional reference signal measurements. In some embodiments, terminal device 110 may receive 483 another set of reference signals (also referred to herein as a second set of reference signals for convenience) based on the set of TCI conditions and determine 483' a third set of QCL parameters based on second measurements for the second set of reference signals. Terminal device 110 may then receive 483'' a PDSCH transmission based on the third set of QCL parameters.

[0092] Alternatively or additionally, terminal device 110 may receive a PDSCH transmission based on the third set of QCL parameters and the QCL parameter compensation information. In some embodiments, terminal device 110 may modify 484 the third set of QCL parameters using the QCL parameter compensation information and receive 484' the PDSCH transmission based on the modified set of QCL parameters.

[0093] In some embodiments, the second set of reference signals may include a set of demodulation reference signals (DMRS) for PDSCH transmissions. In some embodiments, terminal device 110 may measure the set of DMRS and obtain a third set of QCL parameters based solely on the measurements for the set of DMRS.

[0094] In some embodiments, if the first reference signals are periodic or semi-persistent, the set of second reference signals may include another set of the first reference signals, i.e., another transmission opportunity for the first reference signals.

[0095] In some embodiments, the second set of reference signals may include a set of reference signals associated with the first set of reference signals (also referred to herein as a third set of reference signals for convenience). In some embodiments where the first set of reference signals is a set of periodic TRSs, the third set of reference signals may be a set of aperiodic TRSs. In some embodiments, the set of TCI states may be applied to the PDSCH CJT after the most recent additional reference signal transmission after DCI reception.

[0096] In some embodiments, terminal device 110 may receive a PDSCH transmission by applying the set of TCI states and QCL parameter compensation information a certain duration after receiving the DCI. In some embodiments, terminal device 110 may receive a PDSCH transmission by applying the set of TCI states and QCL parameter compensation information a certain duration after transmitting an acknowledgment for receiving the DCI. This duration may be reported as a capability of terminal device 110.

[0097] Process 400 allows PDSCH transmission in a CJT manner to be supported within a unified TCI framework.

[0098] For illustrative purposes, some exemplary embodiments will be described with reference to Figures 5A and 5B. Figure 5A is a schematic diagram illustrating an exemplary communication process 500A using a TRS as a QCL reference, according to some exemplary embodiments of the present disclosure. For illustrative purposes, process 500A will be described with reference to Figure 1.

[0099] 5A , terminal device 110 may receive TRS 1 from TRP 131 and TRS 2 from TRP 132 as QCL references. Terminal device 110 may receive CSI-RS 1 from TRP 131, CSI-RS 2 from TRP 132, CSI-RS 3 from TRP 133, and CSI-RS 4 from TRP 134. Terminal device 110 may send a CSI report to network device 120. Network device 120 may perform network adjustment. In this example, it is assumed that additional adjustment for TRP 132 is performed on mean delay, phase, Doppler shift, or frequency shift. Network device 120 may determine to perform PDSCH CJT using TRPs 131 and 132. The network device 120 may transmit a PDCCH scheduling the PDSCH CJT to the terminal device 110 and transmit the PDSCH CJT via the TRPs 131 and 132 .

[0100] In a modification to the example of FIG. 5A above, if TRP 131 and TRP 133 are used for CJT, the additional RS may be TRS 3 for TRP 133, and network device 120 may need to activate the TCI state for TRP 133 and deactivate the TCI state for TRP 132.

[0101] 5B is a schematic diagram illustrating a communication process 500B using a CSI-RS for channel measurements as a QCL reference, according to some exemplary embodiments of the present disclosure. For illustrative purposes, process 500B will be described with reference to FIG. 1.

[0102] 5B , terminal device 110 may receive CSI-RS 1 from TRP 131 and CSI-RS 2 from TRP 132 as QCL references for channel measurement. Terminal device 110 may further receive CSI-RS 3 from TRP 133 and CSI-RS 4 from TRP 134 for channel measurement. Terminal device 110 may transmit the CSI report to network device 120. Network device 120 may perform network adjustment. In this example, it is assumed that additional adjustment for TRP 132 is performed on mean delay, phase, Doppler shift, or frequency shift. Network device 120 may determine to perform PDSCH CJT using TRPs 131 and 132. Network device 120 may transmit a PDCCH scheduling the PDSCH CJT to terminal device 110 and transmit the PDSCH CJT via TRPs 131 and 132.

[0103] In a modification to the example of FIG. 5B above, if TRP 131 and TRP 133 are used for CJT, the additional RS may be TRS 3 for TRP 133, and network device 120 may need to activate the TCI state for TRP 133 and deactivate the TCI state for TRP 132.

[0104] Other transmission implementations within the unified TCI framework In this embodiment, a TCI state determination solution is provided for transmission without CJT, which will be described in connection with FIG.

[0105] 6 is a schematic diagram illustrating a communication process 600 for determining a TCI for a transmission without a CJT, according to some exemplary embodiments of the present disclosure. For purposes of explanation, the process 600 will be described with reference to FIG.

[0106] 6, network device 120 may transmit 610 a TCI configuration for the PDSCH CJT to terminal device 110. In some embodiments in which two TCI states are indicated, the configuration may indicate that a first TCI state provides reference information for the PDSCH CJT and that a second TCI state provides additional information for the PDSCH CJT that is different from the reference information.

[0107] In some embodiments, the additional information may include at least one of an average delay, a delay spread, a Doppler shift, a Doppler spread, a phase parameter, or a transmit power parameter. In some embodiments, the average delay may include a maximum average delay of the PDSCH CJT. In some embodiments, the delay spread may include a maximum delay spread of the PDSCH CJT. In some embodiments, the phase parameter may include at least one of a phase value, an initial phase, a phase shift, or a phase rotation. In some embodiments, the transmit power parameter may include at least one of a power value or a power offset.

[0108] Other details of the TCI configuration for PDSCH CJT are similar to those described in connection with FIG. 3 and will not be repeated here for the sake of brevity.

[0109] Continuing with reference to Figure 6, network device 120 may transmit 620 a DCI scheduling a PDSCH CJT to terminal device 110 via the PDCCH. The DCI indicates a set of TCI states. The operations of step 610 are similar to those of step 460 of Figure 4 and will not be repeated here for brevity.

[0110] Terminal device 110 may determine a TCI state from the set of TCI states to use in a further transmission (630). When the PDSCH transmission is performed in the CJT manner, the further transmission is not performed in the CJT manner.

[0111] In some embodiments, the further transmission may include a PDCCH transmission. In some embodiments, the further transmission may include a CSI-RS transmission. In some embodiments, the further transmission may include a CSI-RS transmission at the same time-domain position as the PDSCH CJT. In some embodiments, the further transmission may include a PUCCH transmission. In some embodiments, the further transmission may include a PUSCH transmission. In some embodiments, the further transmission may include an SRS transmission.

[0112] In some embodiments, terminal device 110 may receive 631 an indication of the TCI state configured for the further transmission from network device 120. In this way, the TCI state for the further transmission may be decoupled from the TCI state for the PDSCH CJT. In other words, the TCI state for the PDSCH CJT does not apply to the further transmission.

[0113] In some embodiments, terminal device 110 may determine a predetermined TCI state from the set of TCI states as the TCI state (632). Thus, the TCI state for the further transmission may be associated at least in part with the TCI state for the PDSCH CJT. In some embodiments, terminal device 110 may determine a TCI state configured to provide reference information for the PDSCH CJT as the predetermined TCI state. In some embodiments, terminal device 110 may determine a TCI state from the set of TCI states that provides a downlink reference signal with the lowest path loss as the predetermined TCI state.

[0114] In some embodiments, terminal device 110 may receive information about QCL parameter compensation for PDSCH CJT. The operation of receiving the information about QCL parameter compensation is similar to that described in FIG. 3 and will not be repeated here for brevity. In these embodiments, terminal device 110 may prevent the information about QCL parameter compensation from being applied to further transmissions.

[0115] For illustrative purposes, several exemplary embodiments are described below in relation to Embodiments 1 to 3.

[0116] Embodiment 1 In this embodiment, if multiple joint TCI states are indicated for the PDSCH CJT, for PDCCH reception, the QCL assumption may be based on one of the indicated TCI states for the PDSCH CJT. The compensation applied to the PDSCH CJT is not applied to the PDCCH.

[0117] In some embodiments, PDCCH reception may be separated from the TCI state for PDSCH CJT. In other words, the set of TCI states indicated for PDSCH CJT does not apply to PDCCH reception. In some embodiments, RRC configuration may be used to indicate that terminal device 110 may not apply any of the indicated TCI states to CORESET when CJT is enabled. In some embodiments, terminal device 110 assumes that the TCI state or QCL assumption for PDSCH CJT is not identical to any TCI state or QCL assumption applied for CORESET used for reception of DL DCI, regardless of RRC configuration. In some embodiments, terminal device 110 may expect a dedicated TCI state, a configured TCI state, or an indicated TCI state for PDCCH. In some embodiments, terminal device 110 may report its capabilities to network device 120, including information about whether the terminal device supports additional TCI state configurations for PDCCH reception.

[0118] In some embodiments, PDCCH reception may be at least partially associated with the TCI state for the PDSCH CJT. In other words, a set of TCI states indicated for the PDSCH CJT is applicable to PDCCH reception. In some embodiments in which additional information is provided to terminal device 110, an RRC configuration may be used to indicate that terminal device 110 may apply one of the indicated TCI states to CORESET. For example, one of the indicated TCI states may be the first or second of the indicated joint TCI states. In some embodiments, terminal device 110 may report its capabilities to network device 120, including information regarding terminal device support for TCI state settings for the PDSCH CJT that can also be used for PDCCH reception.

[0119] In some embodiments, some rules may be defined. For example, the PDCCH is always transmitted from the reference / strongest TRP. In other words, it is assumed that the QCL according to the TCI state corresponds to the reference / strongest TRP. In another example, if two or more TCI states are indicated for the PDSCH CJT, the PDCCH is always transmitted with the QCL assumption of the first indicated joint TCI state. In yet another example, the terminal device 110 may apply the first TCI state of the two TCI states that is mapped to the two TCI states and corresponds to the lowest TCI codepoint among the TCI codepoints applicable to the PDSCH.

[0120] In some embodiments where there are two TCI states, one TCI state, or no TCI indication for the PDSCH CJT, if network compensation is applied to the PDSCH CJT, compensation is not applied to the PDCCH, and the PDCCH is always transmitted without compensation. For example, terminal device 110 may use the original / old QCL assumption configured / indicated for the PDSCH CJT for PDCCH reception.

[0121] In some embodiments, the ratio of PDCCH EPRE to CSI-RS energy per resource element (EPRE) is assumed as 0 dB, where the CSI-RS is configured as the QCL reference in the TCI state corresponding to the reference / strongest TRP, or in the first indicated joint TCI state if more than one TCI state is indicated for the PDSCH CJT.

[0122] In some embodiments, the ratio of PDCCH EPRE to CSI-RS EPRE is indicated by the network device 120, where the CSI-RS is set as the QCL reference in the TCI state corresponding to the reference / strongest TRP, or in the first indicated joint TCI state when more than one TCI state is indicated for the PDSCH CJT.

[0123] In some embodiments, the ratio of PDCCH EPRE to CSI-RS EPRE is related to the power offset between the dedicated DL-RS configured as QCL reference in the TCI state for the PDCCH and the CSI-RS configured as QCL reference in the TCI state corresponding to the reference / strongest TRP or in the first indicated joint TCI state if more than one TCI state is indicated for the PDSCH CJT.

[0124] Thus, a correct QCL assumption can be provided for the PDCCH.

[0125] Embodiment 2 In this embodiment, for a CSI-RS transmitted on the same OFDM symbol as a PDSCH CJT with two TCI states enabled, the QCL assumption may be based on one of the indicated TCI states for the PDSCH CJT, and no compensation is applied to the CSI-RS measurements.

[0126] In some embodiments, the CSI-RS may be an aperiodic CSI-RS resource in a CSI-RS resource set associated with a CSI trigger state. In some embodiments, the CSI-RS may be a periodic or semi-persistent CSI-RS. In some embodiments, other signals, for example, other CSI-RS, may also be transmitted on the same OFDM symbol as the PDSCH CJT and the CSI-RS.

[0127] In some embodiments, CSI-RS measurements may be separated from the TCI states for the PDSCH CJT. In other words, the set of TCI states indicated for the PDSCH CJT does not apply to CSI-RS measurements. In some embodiments, an RRC configuration may be used to signal that terminal device 110 may not apply any of the indicated TCI states to the CSI-RS resource or resource set if CJT is enabled. In some embodiments, terminal device 110 assumes that the TCI state or QCL assumption for the PDSCH CJT is not identical to any TCI state or QCL assumption applied for the CORESET used for reception of DL DCI, regardless of the RRC configuration. In some embodiments, terminal device 110 may expect QCL information to be present exclusively for CSI-RS. In some embodiments, terminal device 110 may report its capabilities to network device 120, including information regarding the terminal's support of additional QCL information for CSI-RS on the same symbol.

[0128] In some embodiments, CSI-RS measurements may be at least partially associated with the TCI state for the PDSCH CJT on the same OFDM symbol. In other words, the set of TCI states indicated for the PDSCH CJT is applicable to the CSI-RS on the same symbol. In some embodiments in which additional information is provided to the terminal device 110, an RRC configuration may be used to indicate that the terminal device 110 may apply one of the indicated TCI states to the CORESET. For example, one of the indicated TCI states may be the first or second of the indicated joint TCI states. In some embodiments, the terminal device 110 may report its capabilities to the network device 120, including information regarding whether the terminal device supports TCI state settings for the PDSCH CJT that can also be used for the CSI-RS on the same symbol.

[0129] In some embodiments, several rules may be defined. For example, assume that the QCL of the reference / strongest TRP previously reported by the terminal device 110 is used. In another example, if two or more TCI states are indicated for the PDSCH CJT, it may always be assumed that the first indicated joint TCI state is used. In yet another example, the terminal device 110 may apply the first TCI state of the two TCI states that is mapped to the two TCI states and corresponds to the lowest TCI codepoint applicable to the PDSCH.

[0130] In some embodiments where there are two TCI states, one TCI state, or no TCI indication for the PDSCH CJT, if network compensation is applied to the PDSCH CJT, compensation is not applied to the CSI-RS measurements. For example, terminal device 110 may use the original / old QCL assumption configured / indicated for the PDSCH CJT for the CSI-RS measurements. In some alternative embodiments, compensation may also be applied to the CSI-RS measurements. In this case, terminal device 110 may need to report in the CSI report that compensation has been applied.

[0131] Thus, a correct QCL assumption can be provided for CSI-RS measurements.

[0132] Embodiment 3 In this embodiment, when multiple joint TCI states are indicated for the PDSCH CJT, for the UL transmission, the transmit power may be determined based on the TCI state among the set of TCI states that provides the DL RS with the smallest path loss. In some embodiments, the UL transmission may be a PUSCH, a PUCCH, or an SRS. Assume that two TCI states are mapped to one TCI codepoint in the DCI for the PDSCH CJT.

[0133] In some embodiments, UL transmission may be separated from the TCI states for the PDSCH CJT. In other words, the set of TCI states indicated for the PDSCH CJT does not provide power control parameters and / or path loss reference signal information for PUSCH, PUCCH, or SRS transmissions. In some embodiments, when CJT is enabled, RRC configuration may be used to indicate to terminal device 110 that none of the indicated TCI states may apply to PUSCH transmissions or SRS resources configured for codebook or non-codebook-based PUSCH transmissions. In some embodiments, terminal device 110 may expect dedicated power control parameters and / or path loss reference signal information configured for PUCCH, PUSCH, or SRS, respectively or jointly. In some embodiments, terminal device 110 may report its capabilities to network device 120, including information regarding the terminal's support of additional power control parameters and / or path loss reference signal information for PUCCH, PUSCH, or SRS, respectively or jointly.

[0134] In some embodiments, an UL transmission may be at least partially associated with a TCI state for the PDSCH CJT. In other words, the set of TCI states indicated for the PDSCH CJT may provide power control parameters and / or path loss reference signal information for PUSCH, PUCCH, or SRS transmissions. In some embodiments in which additional information is provided to terminal device 110, an RRC configuration may be used to indicate that terminal device 110 may apply power control parameters and / or path loss reference signal information associated with one of the indicated TCI states to a PUSCH, PUCCH, or SRS transmission. For example, one of the indicated TCI states may be the first or second of the indicated joint TCI states.

[0135] In some embodiments, several rules may be defined. For example, the PUSCH, PUCCH, or SRS transmit power is always determined based on the TCI state that provides the DL RS with the smallest path loss. In other words, it is proposed that the transmit power be determined based on the TCI state corresponding to the reference TRP, the closest TRP, or the strongest TRP. The transmit power may be minimized depending on the power control parameter setting and the path loss. In another example, the PUSCH, PUCCH, or SRS transmit power is always transmitted with the power control parameter associated with the first indicated joint TCI state. In some embodiments, the terminal device 110 may report its capabilities to the network device 120, including information about the terminal device that supports the TCI state setting for the PDSCH CJT that can also be used to determine the power control parameters and / or path loss reference signal information for the PUCCH, PUSCH, or SRS, individually or jointly.

[0136] In some embodiments, if network compensation is applied to the PDSCH CJT (in this case, the most likely example is that the network device 120 compensates for DL ​​Tx power), this compensation is not applied to the path loss measurement, and this compensation is not applied to the UL power compensation.

[0137] In this way, the correct power control parameters can be provided for the terminal device.

[0138] By the process 600, when the PDSCH is performed in the CJT manner, other transmissions can also be performed correctly. Note that the above processes 300 to 600 may be performed separately or in any suitable combination.

[0139] Example of the method Therefore, embodiments of the present disclosure provide communication methods implemented in a terminal device and a network device, which are described below with reference to Figures 7-8.

[0140] 7 illustrates an exemplary communication method 700 implemented in a terminal device, according to some embodiments of the present disclosure. For example, method 700 may be performed in terminal device 110 as shown in FIG. 1. For purposes of explanation, method 700 will be described with reference to FIG. 1. It should be understood that method 700 may include additional blocks not shown and / or omit some blocks that are shown, and that the scope of the present disclosure is not limited in this respect.

[0141] In block 710, the terminal device 110 receives DCI scheduling PDSCH transmission in the CJT scheme, the DCI indicating a set of TCI states.

[0142] In block 720, the terminal device 110 receives information on QCL parameter compensation for PDSCH transmission. In some embodiments, the DCI may include the information on QCL parameter compensation. In this case, the terminal device may obtain the information on QCL parameter compensation from the DCI.

[0143] In some embodiments, the QCL parameter compensation information includes at least one of compensation for a time domain parameter, compensation for a frequency domain parameter, compensation for a phase parameter, compensation for a delay parameter, compensation for a Doppler parameter, compensation for transmit power, or an indication of whether QCL parameter compensation is applied.

[0144] In block 730, terminal device 110 receives a PDSCH transmission based on the set of TCI states and the QCL parameter compensation information.

[0145] In some embodiments, terminal device 110 may receive a first set of reference signals based on the set of TCI states and determine a first set of QCL parameters based on first measurements for the first set of reference signals. Terminal device 110 may receive a PDSCH transmission based on the first set of QCL parameters and the QCL parameter compensation information. In some embodiments, terminal device 110 may determine a second set of QCL parameters by modifying the first set of QCL parameters based on the QCL parameter compensation information and receive a PDSCH transmission based on the second set of QCL parameters.

[0146] In some embodiments, the first set of reference signals is received based on the set of TCI conditions at a first timing. In these embodiments, the terminal device 110 may receive a second set of reference signals based on the set of TCI conditions at a second timing that is later than the first timing, and determine a third set of QCL parameters based on second measurements for the second set of reference signals. The terminal device 110 may receive a PDSCH transmission based on the third set of QCL parameters.

[0147] In some embodiments, a first set of reference signals is received based on a set of TCI conditions at a first timing. In these embodiments, terminal device 110 may receive a second set of reference signals based on a set of TCI conditions at a second timing that is later than the first timing, and determine a third set of QCL parameters based on second measurements for the second set of reference signals. Terminal device 110 may then receive a PDSCH transmission based on the third set of QCL parameters and the QCL parameter compensation information.

[0148] In some embodiments, terminal device 110 may ignore the first measurements for the first set of reference signals.

[0149] In some embodiments, the second set of reference signals may include one of a set of DMRS for PDSCH transmissions, another first set of reference signals, or a third set of reference signals associated with the first set of reference signals.

[0150] In some embodiments, the first reference signal may be a TRS. In some embodiments, the first reference signal may be a CSI-RS.

[0151] In some embodiments, the terminal device 110 may report its capabilities, which may include at least one of information of support for QCL parameter compensation or duration of QCL parameter compensation.

[0152] In some embodiments, terminal device 110 may receive a PDSCH transmission by applying the set of TCI states and QCL parameter compensation information after a certain duration from receiving the DCI.

[0153] By the method 700, PDSCH transmission in a CJT manner can be well supported within a unified TCI framework.

[0154] 8 illustrates another exemplary communication method 800 implemented in a terminal device, according to some embodiments of the present disclosure. For example, method 800 may be performed in terminal device 110, such as that shown in FIG. 1. For purposes of explanation, method 800 will be described with reference to FIG. 1. It should be understood that method 800 may include additional blocks not shown and / or omit some blocks that are shown, and that the scope of the present disclosure is not limited in this respect.

[0155] In block 810, terminal device 120 schedules PDSCH transmission in the CJT scheme and receives DCI indicating a set of TCI states.

[0156] In block 820, the terminal device 120 determines a TCI state from the set of TCI states to be used in a further transmission, and when the PDSCH transmission is performed in the CJT manner, the further transmission is not performed in the CJT manner.

[0157] In some embodiments, the further transmission may include at least one of a PDCCH transmission, a CSI-RS transmission at the same time domain position as the PDSCH transmission, a PUCCH transmission, or a PUSCH transmission.

[0158] In some embodiments, the terminal device may receive an indication of a TCI state configured for a further transmission and determine a predetermined TCI state from the set of TCI states as the TCI state. In some embodiments, the terminal device may determine a TCI state configured to provide reference information for a PDSCH transmission as the predetermined TCI state. In some embodiments, the further transmission includes a PUCCH transmission or a PUSCH transmission, the terminal device 110 may determine a TCI state from the set of TCI states that provides a downlink reference signal with the lowest path loss as the predetermined TCI state.

[0159] In some embodiments, terminal device 110 may receive information of QCL parameter compensation for a PDSCH transmission and may not apply the QCL parameter compensation information to further transmissions.

[0160] In some embodiments, the set of TCI states may include a first TCI state and a second TCI state, in which the terminal device may receive a configuration indicating that the first TCI state provides reference information for the PDSCH transmission and that the second TCI state provides additional information for the PDSCH transmission that is different from the reference information.

[0161] In some embodiments, the additional information may include at least one of an average delay, a delay spread, a Doppler shift, a Doppler spread, a phase parameter, or a transmit power parameter. In some embodiments, the average delay may include a maximum average delay of the PDSCH transmission. In some embodiments, the delay spread may include a maximum delay spread of the PDSCH transmission. In some embodiments, the phase parameter may include at least one of a phase value, an initial phase, a phase shift, or a phase rotation. In some embodiments, the transmit power parameter may include at least one of a power value or a power offset.

[0162] 9 is a schematic block diagram of an apparatus 900 suitable for implementing embodiments of the present disclosure. The apparatus 900 may be considered as another exemplary implementation of the terminal device 110 and the network device 120 shown in FIG. 1. Accordingly, the apparatus 900 may be implemented in, or as at least a part of, the terminal device 110 and the network device 120.

[0163] As shown, the apparatus 900 comprises a processor 910, a memory 920 coupled to the processor 910, a suitable transmitter (TX) and receiver (RX) 940 coupled to the processor 910, and a communication interface coupled to the TX / RX 940. The memory 910 stores at least a portion of a program 930. The TX / RX 940 is used for bidirectional communication. The TX / RX 940 has at least one antenna to facilitate communication, although the access nodes referred to herein may actually have multiple antennas. The communication interface may represent any interface required for communication with other network elements, such as an X2 interface for bidirectional communication between eNBs, an S1 interface for communication between a Mobility Management Entity (MME) / Serving Gateway (S-GW) and an eNB, a Un interface for communication between an eNB and a relay node (RN), or a Uu interface for communication between an eNB and a terminal device.

[0164] It is assumed that the program 930 includes program instructions that, when executed by the associated processor 910, enable the device 900 to operate according to embodiments of the present disclosure, as described herein with reference to FIG. 1. The embodiments herein may be implemented by computer software executable by the processor 910 of the device 900, by hardware, or by a combination of software and hardware. The processor 910 may be configured to implement various embodiments of the present disclosure. Furthermore, the combination of the processor 910 and the memory 920 may form a processing means 950 suitable for implementing various embodiments of the present disclosure.

[0165] Memory 920 may be of any type suitable for a local technology network and may be implemented using any suitable data storage technology, including, by way of non-limiting example, non-transitory computer-readable storage media, semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. While only one memory 920 is shown in device 900, there may be several physically distinct memory modules within device 900. Processor 910 may be of any type suitable for a local technology network and may include, by way of non-limiting example, one or more of a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. Device 900 may have multiple processors, for example, application-specific integrated circuit chips time-slaved to a clock that synchronizes the main processor.

[0166] In some embodiments, a terminal device comprises circuitry configured to schedule a PDSCH transmission in a CJT scheme, receive the DCI indicating a set of TCI states, receive information on QCL parameter compensation for the PDSCH transmission, and receive the PDSCH transmission based on the set of TCI states and the information on QCL parameter compensation.

[0167] In some embodiments, a terminal device comprises a circuit configured to schedule a PDSCH transmission in a CJT manner, receive the DCI indicating a set of TCI states, and determine a TCI state from the set of TCI states to be used in a further transmission, wherein when the PDSCH transmission is performed in the CJT manner, the further transmission is not performed in the CJT manner.

[0168] As used herein, the term "circuitry" may refer to a hardware circuit and / or a combination of a hardware circuit and software. For example, a circuit may be a combination of analog and / or digital hardware circuitry and software / firmware. As yet another example, a circuit may be any portion of a hardware processor with software, including a digital signal processor, software, and one or more memories, that cooperate to cause a device, such as a terminal device or a network device, to perform various functions. In yet another example, a circuit may be a hardware circuit and / or a processor, such as a microprocessor or portion thereof, that requires software / firmware for operation, although software may not be present if not necessary for operation. As used herein, the term "circuitry" also includes an implementation of a hardware circuit or one or more processors only, or a hardware circuit or portion of one or more processors and its / their associated software and / or firmware.

[0169] In summary, the embodiments of the present disclosure can provide the following solutions:

[0170] In one solution, a terminal device includes a processor, and the processor is configured to cause the terminal device to schedule a PDSCH transmission in a CJT scheme, receive the DCI indicating a set of TCI states, receive information on QCL parameter compensation for the PDSCH transmission, and receive the PDSCH transmission based on the set of TCI states and the information on QCL parameter compensation.

[0171] In some embodiments, the DCI includes information on the QCL parameter compensation, and the terminal device receives the information on the QCL parameter compensation by obtaining the information on the QCL parameter compensation from the DCI.

[0172] In some embodiments, the QCL parameter compensation information includes at least one of compensation for a time domain parameter, compensation for a frequency domain parameter, compensation for a phase parameter, compensation for a delay parameter, compensation for a Doppler parameter, compensation for transmit power, or an indication of whether the QCL parameter compensation is applied.

[0173] In some embodiments, the terminal device receives the PDSCH transmission by receiving a first set of reference signals based on the set of TCI states, determining a first set of QCL parameters based on first measurements for the first set of reference signals, and receiving the PDSCH transmission based on the first set of QCL parameters and information about the QCL parameter compensation.

[0174] In some embodiments, the terminal device receives the PDSCH transmission by determining a second set of QCL parameters by modifying the first set of QCL parameters based on the information of the QCL parameter compensation, and receiving the PDSCH transmission based on the second set of QCL parameters.

[0175] In some embodiments, a first set of reference signals is received based on the set of TCI states at a first timing, and the terminal device receives the PDSCH transmission by receiving a second set of reference signals based on the set of TCI states at a second timing that is later than the first timing, determining a third set of QCL parameters based on second measurement values ​​for the second set of reference signals, and receiving the PDSCH transmission based on the third set of QCL parameters.

[0176] In some embodiments, a first set of reference signals is received based on the set of TCI states at a first timing. In these embodiments, the terminal device receives the PDSCH transmission by receiving a second set of reference signals based on the set of TCI states at a second timing that is later than the first timing, determining a third set of QCL parameters based on second measurements for the second set of reference signals, and receiving the PDSCH transmission based on the third set of QCL parameters and information about the QCL parameter compensation.

[0177] In some embodiments, the terminal device further ignores first measurements for the first set of reference signals.

[0178] In some embodiments, the second set of reference signals includes one of a set of DMRS for the PDSCH transmission, another first set of reference signals, or a third set of reference signals associated with the first set of reference signals.

[0179] In some embodiments, the first reference signal is a TRS or a CSI-RS.

[0180] In some embodiments, the terminal device further reports capabilities of the terminal device, the capabilities including at least one of information of support for the QCL parameter compensation or a duration of the QCL parameter compensation.

[0181] In some embodiments, the terminal device further receives the PDSCH transmission by applying the set of TCI states and the QCL parameter compensation information after a certain duration from receiving the DCI.

[0182] In another solution, a terminal device comprises a processor, the processor being configured to cause the terminal device to schedule a PDSCH transmission in a CJT manner, receive the DCI indicating a set of TCI states, and determine a TCI state from the set of TCI states to be used in a further transmission, wherein when the PDSCH transmission is performed in the CJT manner, the further transmission is not performed in the CJT manner.

[0183] In some embodiments, the further transmission comprises at least one of a PDCCH transmission, a CSI-RS transmission at the same time domain position as the PDSCH transmission, a PUCCH transmission, or a PUSCH transmission.

[0184] In some embodiments, the terminal device determines the TCI state by receiving an indication of the TCI state that is set for the further transmission or by determining a predetermined TCI state from the set of TCI states as the TCI state.

[0185] In some embodiments, the terminal device determines the predetermined TCI state by determining a TCI state that is configured to provide reference information for the PDSCH transmission as the predetermined TCI state.

[0186] In some embodiments, the further transmission includes a PUCCH transmission or a PUSCH transmission, and the terminal device determines the predetermined TCI state by determining, from the set of TCI states, a TCI state that provides a downlink reference signal with the lowest path loss as the predetermined TCI state.

[0187] In some embodiments, the terminal device further receives information of QCL parameter compensation for the PDSCH transmission, and prevents the QCL parameter compensation information from being applied to the further transmission.

[0188] In some embodiments, the set of TCI states includes a first TCI state and a second TCI state, and the terminal device further receives a configuration indicating that the first TCI state provides reference information for the PDSCH transmission and that the second TCI state provides additional information for the PDSCH transmission that is different from the reference information.

[0189] In some embodiments, the additional information includes at least one of a mean delay, a delay spread, a Doppler shift, a Doppler spread, a phase parameter, or a transmit power parameter.

[0190] In some embodiments, the average delay comprises a maximum average delay of the PDSCH transmission, or the delay spread comprises a maximum delay spread of the PDSCH transmission.

[0191] In another solution, a communication method includes receiving, at a terminal device, the DCI that schedules a PDSCH transmission in a CJT scheme and indicates a set of TCI states; receiving information about QCL parameter compensation for the PDSCH transmission; and receiving the PDSCH transmission based on the set of TCI states and the information about QCL parameter compensation.

[0192] In another solution, a communication method includes scheduling a PDSCH transmission in a CJT manner, receiving the DCI in a terminal device indicating a set of TCI states, and determining a TCI state from the set of TCI states to be used in a further transmission, wherein when the PDSCH transmission is performed in the CJT manner, the further transmission is not performed in the CJT manner.

[0193] Overall, 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 executable by a controller, microprocessor, or other computing device. While various aspects of embodiments of the present disclosure have been illustrated and described using block diagrams, flowcharts, or other pictorial representations, it should be understood that the blocks, devices, systems, techniques, or methods described herein may be implemented, by way of non-limiting example, in hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing device, or any combination thereof.

[0194] The present disclosure further provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as instructions included in program modules, that execute in a device on a target real or virtual processor to perform the processes or methods described above with reference to FIGS. 1-8. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data types. In various embodiments, the functionality of the program modules may be combined or split between program modules as desired. The machine-executable instructions of the program modules may be executed in local or distributed devices. In a distributed device, program modules may be located in both local and remote storage media.

[0195] Program code for carrying out the 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, a special-purpose computer, or other programmable data processing device, and when executed by the processor or controller, cause the program code to implement the functions / acts specified in the flowcharts and / or block diagrams. The program code may run entirely on the machine, partially on the machine, as a separate software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0196] The above-described program code may be embodied on a machine-readable medium, which may be any tangible medium that can contain or store a program used by or associated with an instruction execution system, apparatus, or device. The machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. The machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the aforementioned media. More specific examples of a machine-readable storage medium may include 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), 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 above.

[0197] It should be noted that, although operations have been described in a particular order, it should not be understood that performing such operations in the particular order shown, or in any sequential order, or performing all of the operations described, is required to achieve desirable results. In some cases, multitasking and parallel processing may be advantageous. Similarly, while several specific implementation details are included in the above discussion, these should not be construed as limitations on the scope of the disclosure, but rather as descriptions of features that may be specific to particular embodiments. Some features that are described in the context of individual 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.

[0198] Although the present disclosure has been described in language specific to structural features and / or methodological acts, it should be understood that the present disclosure, as 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

1. A terminal device, a processor; The processor causes the terminal device to receiving downlink control information (DCI) that schedules a physical downlink shared channel (PDSCH) transmission in a coherent joint transmission (CJT) scheme and indicates a set of transmission configuration indicator (TCI) states; receiving quasi co-location (QCL) parameter compensation information for the PDSCH transmission; receiving the PDSCH transmission based on the set of TCI states and the QCL parameter compensation information. Terminal device.

2. The DCI includes information of the QCL parameter compensation, The terminal device receives the information on the QCL parameter compensation by acquiring the information on the QCL parameter compensation from the DCI. The terminal device according to claim 1 .

3. The information of the QCL parameter compensation is Compensation for time domain parameters, Compensation for frequency domain parameters, compensation for phase parameters, Compensation for delay parameters, Compensation for Doppler parameters, Compensation for transmission power, or an indication of whether the QCL parameter compensation is applied or not. The terminal device according to claim 1 .

4. The terminal device receiving a first set of reference signals based on the set of TCI states; determining a first set of QCL parameters based on first measurements for the first set of reference signals; receiving the PDSCH transmission based on the first set of QCL parameters and the QCL parameter compensation information, thereby receive the PDSCH transmission The terminal device according to claim 1 .

5. The terminal device determining a second set of QCL parameters by modifying the first set of QCL parameters based on the QCL parameter compensation information; receiving the PDSCH transmission based on the second set of QCL parameters, whereby receive the PDSCH transmission The terminal device according to claim 4.

6. a first set of reference signals is received based on the set of TCI states at a first timing; The terminal device receiving a second set of reference signals based on the set of TCI states at a second timing that is later than the first timing; determining a third set of QCL parameters based on second measurements for the second set of reference signals; receiving the PDSCH transmission based on the third set of QCL parameters, whereby receive the PDSCH transmission The terminal device according to claim 1 .

7. a first set of reference signals is received based on the set of TCI states at a first timing; The terminal device receiving a second set of reference signals based on the set of TCI states at a second timing that is later than the first timing; determining a third set of QCL parameters based on second measurements for the second set of reference signals; receiving the PDSCH transmission based on the third set of QCL parameters and the QCL parameter compensation information, thereby receive the PDSCH transmission The terminal device according to claim 1 .

8. The terminal device further Ignoring first measurements for the first set of reference signals.

8. The terminal device according to claim 6 or 7.

9. The second set of reference signals comprises: a set of demodulation reference signals (DMRS) for the PDSCH transmission; another set of first reference signals; or a third set of reference signals associated with the first set of reference signals.

8. The terminal device according to claim 6 or 7.

10. The first reference signal is a tracking reference signal (TRS) or a channel state information reference signal (CSI-RS). The terminal device according to claim 9.

11. The terminal device further reporting the capabilities of said terminal device; The ability is Supporting information for the QCL parameter compensation; or the duration of the QCL parameter compensation. The terminal device according to claim 1 .

12. The terminal device further receiving the PDSCH transmission by applying the set of TCI states and the QCL parameter compensation information after a certain duration from receiving the DCI; The terminal device according to claim 1 .

13. A terminal device, a processor; The processor causes the terminal device to receiving downlink control information (DCI) that schedules a physical downlink shared channel (PDSCH) transmission in a coherent joint transmission (CJT) scheme and indicates a set of transmission configuration indicator (TCI) states; determining a TCI state from the set of TCI states to be used in further transmissions; When the PDSCH transmission is performed in the CJT manner, the further transmission is not performed in the CJT manner. Terminal device.

14. The further transmission may comprise: Physical downlink control channel (PDCCH) transmission; A channel state information reference signal (CSI-RS) transmission at the same time domain position as the PDSCH transmission; physical uplink control channel (PUCCH) transmission, or physical uplink shared channel (PUSCH) transmission. The terminal device according to claim 13.

15. The terminal device receiving an indication of the TCI state that is set for the further transmission; or determining a predetermined TCI state from the set of TCI states as the TCI state; Determining the TCI Status The terminal device according to claim 13.

16. The terminal device determining a TCI state configured to provide reference information for the PDSCH transmission as the predetermined TCI state; The terminal device according to claim 15.

17. the further transmission comprises a physical uplink control channel (PUCCH) transmission or a physical uplink shared channel (PUSCH) transmission; The terminal device determining a TCI state that provides a downlink reference signal with the lowest path loss among the set of TCI states as the predetermined TCI state; The terminal device according to claim 15.

18. The terminal device further receiving information on quasi co-location (QCL) parameter compensation for the PDSCH transmission; Preventing the QCL parameter compensation information from being applied to the further transmission. The terminal device according to claim 13.

19. the set of TCI conditions includes a first TCI condition and a second TCI condition; The terminal device further receiving a configuration indicating that the first TCI state provides reference information for the PDSCH transmission and that the second TCI state provides additional information for the PDSCH transmission that differs from the reference information; The terminal device according to claim 1 or 13.

20. A method of communication comprising: receiving, at a terminal device, downlink control information (DCI) that schedules a physical downlink shared channel (PDSCH) transmission in a coherent joint transmission (CJT) scheme and indicates a set of transmission configuration indicator (TCI) states; receiving information about quasi co-location (QCL) parameter compensation for the PDSCH transmission; receiving the PDSCH transmission based on the set of TCI states and the QCL parameter compensation information; A method comprising:

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