Terminal devices, network devices, and methods

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

Background Art

[0002] As is well known, a unified TCI framework has been introduced to replace the TCI state or spatial relation framework for beam indication. Recently, it has been proposed to support physical downlink shared channel (PDSCH) transmission in a coherent joint transmission (CJT) scheme. However, it remains unclear how to support PDSCH transmission in the CJT scheme within the unified TCI framework, and further research is needed.

Summary of the Invention

Problems to be Solved by the Invention

[0003] Generally, 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 Problems

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

[0005] In a second embodiment, a terminal device is provided, the terminal device comprising a processor, the processor configured to schedule a PDSCH transmission in the CJT scheme, receive the DCI indicating a set of TCI states, and determine which of the set of TCI states will be used in a further transmission, wherein when the PDSCH transmission is performed in the CJT scheme, the further transmission is not performed in the CJT scheme.

[0006] In a third embodiment, a method of communication is provided. The method includes scheduling a PDSCH transmission in a CJT scheme, receiving the DCI indicating a set of TCI states in a terminal device, receiving information about QCL parameter compensation for the PDSCH transmission, and receiving the PDSCH transmission based on the set of TCI states and the QCL parameter compensation information.

[0007] In a fourth embodiment, a method of communication is provided. The method includes scheduling a PDSCH transmission in a CJT scheme, receiving the DCI representing a set of TCI states in a terminal device, and determining which of the set of TCI states is to be used in a further transmission, wherein the PDSCH transmission is performed in a CJT scheme and the further transmission is not performed in a CJT scheme.

[0008] In a fifth embodiment, a computer-readable medium storing instructions is provided. When the instructions are executed on at least one processor, the instructions cause the at least one processor to perform the method described in the third or fourth embodiment of the present disclosure.

[0009] It should be understood that the summary portion of the invention is not intended to identify any important or fundamental features of the embodiments of this disclosure, nor to limit the scope of this disclosure. Other features of this disclosure should be readily apparent from the following description. [Brief explanation of the drawing]

[0010] The above-mentioned and other objectives, features, and advantages of this disclosure will be further clarified by describing in more detail some embodiments of this disclosure in the attached drawings.

[0011] [Figure 1] This figure shows an exemplary communication network on which the embodiments of this disclosure can be implemented.

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

[0013] [Figure 2B]Schematic diagram showing problems in other transmissions when PDSCH transmission is performed in the CJT mode according to some exemplary embodiments of the present disclosure.

[0014] [Figure 3] Schematic diagram showing a communication process for configuring TCI for PDSCH transmission in the CJT mode according to some exemplary embodiments of the present disclosure.

[0015] [Figure 4] Schematic diagram showing a communication process for PDSCH transmission in the CJT mode according to some exemplary embodiments of the present disclosure.

[0016] [Figure 5A] Schematic diagram showing an exemplary communication process using the TRS as a QCL reference according to some exemplary embodiments of the present disclosure.

[0017] [Figure 5B] Schematic diagram showing a communication process using the CSI-RS for channel measurement as a QCL reference according to some exemplary embodiments of the present disclosure.

[0018] [Figure 6] Schematic diagram showing a communication process for determining TCI for transmission without CJT according to some exemplary embodiments of the present disclosure.

[0019] [Figure 7] Flowchart showing an exemplary method executed by a terminal device according to some embodiments of the present disclosure.

[0020] [Figure 8] Flowchart showing another exemplary method executed by a terminal device according to some embodiments of the present disclosure.

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

[0022] In the figure, the same or similar reference numerals represent the same or similar elements.

Embodiments for Carrying out 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 merely described for the purpose of explanation and are helpful for those skilled in the art to understand and implement the present disclosure, and do not imply any limitation to the scope of the present disclosure. The present disclosure described in the present disclosure can be implemented in various ways other than those described below.

[0024] In the following description and claims, unless otherwise defined, all technical and scientific terms used have the same meaning as commonly understood by those skilled in the art to which the present disclosure pertains.

[0025] As used herein, the term “terminal device” refers to any device having wireless or wired communication capabilities. Examples of terminal devices include user equipment (UE), personal computers, desktops, mobile phones, cellular phones, smartphones, personal digital assistants (PDA), 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 communication where X represents pedestrians, vehicles, or infrastructure / networks, devices for Integrated Access and Backhaul (IAB), Small Data Transmission (SDT), mobility, Multicast and Broadcast Services (MBS), positioning, dynamic / flexible redundancy in commercial networks, RedCap (reduced capability), and High Altitude Platforms (HAP) encompassing satellites and Unmanned Aircraft Systems (UAS). This includes satellite-mounted vehicles or aircraft-mounted vehicles within a non-terrestrial network (NTN), including a Platform; extended reality (XR) devices that include 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 human operators and are commonly referred to as drones."Terminal equipment" includes, but is not limited to, devices on a vehicle, high-speed train (HST), or image acquisition devices such as digital cameras, sensor game devices, music storage and playback devices, or internet devices that enable wireless or wired internet access and browsing. "Terminal equipment" may further have "multicast / broadcast" capabilities to support public safety and mission-critical, V2X applications, transparent IPv4 / IPv6 multicast distribution, IPTV, smart TV, wireless services, wireless software distribution, group communications, and IoT applications. It may also incorporate one or more Subscriber Identity Modules (SIMs), known as multi-SIMs. The term "Terminal equipment" 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 that can provide or host a cell or coverage on which terminal devices can communicate. Examples of network devices include, but are not limited to, Node B (NodeB or NB), Evolutionary Node B (eNodeB or eNB), Next Generation Node B (gNB), Transmission Reception Point (TRP), Remote Radio Unit (RRU), Radio Head (RH), Remote Radio Head (RRH), Low-Power Nodes such as IAB Nodes, Femto Nodes, and Pico Nodes, Reconfigurable Intelligent Surfaces (RIS), and Network Control Repeaters.

[0027] Terminal devices or network devices may possess artificial intelligence (AI) or machine learning capabilities. Generally, this includes trained models derived from large amounts of data collected for specific functions, which can be used to predict certain information.

[0028] Terminal or network devices 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). Furthermore, they can operate on licensed / unlicensed / shared spectrum. Terminal devices may have two or more connections to network devices under multi-radio dual connectivity (MR-DC) application scenarios. Terminal or network devices can operate in full-duplex, flexible-duplex, and cross-split-duplex modes.

[0029] Network devices may have functions for network energy saving, self-organizing networks (SON), and minimization of drive tests (MDT). Terminals may have power saving functions.

[0030] Embodiments of this disclosure may be implemented, for example, in test equipment such as signal generators, signal analyzers, spectrum analyzers, network analyzers, test terminal devices, test network devices, and channel emulators.

[0031] Embodiments of this disclosure may be implemented in accordance with any generation of communication protocols currently known or to be developed in the future. Examples of communication protocols include, but are not limited to, the 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, the terminal device may be connected to a first network device and a second network device. One of the first and second network devices may be a master node and the other a secondary node. The first and second network devices 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 different RATs may be transmitted to the terminal device from at least one of the first or second network devices. 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 settings of the terminal device set by the second network device may be transmitted from the second network device via the first network device. Information regarding the reconfiguration of terminal devices set by the second network device may be transmitted from the second network device directly to the terminal devices or via the first network device.

[0033] The singular forms “one” and “the foregoing” used herein also include the plural form unless explicitly indicated in the context. The term “including” and its variations should be understood as non-restrictive, meaning “including, but not limited to.” The term “based on” should be understood as “at least partially based 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 identical subjects. The following may include other explicit and implicit definitions.

[0034] In some examples, values, procedures, or devices are referred to as “best,” “lowest,” “highest,” “minimum,” “maximum,” etc. Such descriptions are intended to show that a choice can be made from many commonly used functional alternatives, and it should be understood that such a choice does not necessarily have to be better, smaller, higher, or otherwise preferable than other choices.

[0035] As mentioned above, it remains unclear how PDSCH transmissions in the CJT scheme will be supported within the Unified TCI Framework. For example, it is unclear how PDSCH transmissions in the CJT scheme will be implemented within the Unified TCI Framework. It is also unclear how other transmissions will be handled if PDSCH transmissions are performed in the CJT scheme.

[0036] In view of this, embodiments of the present disclosure provide a communication solution to overcome the above-mentioned problems or other potential problems. In one solution, a terminal device schedules a PDSCH transmission in the CJT scheme, receives a 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 QCL parameter compensation information, the terminal device receives the PDSCH transmission. Thus, the PDSCH transmission in the CJT scheme can be correctly performed within a unified TCI framework.

[0037] In an alternative solution, the terminal device schedules a PDSCH transmission in the CJT scheme and receives a DCI indicating a set of TCI states. The terminal device determines which TCI states from the set of TCI states are to be used in a further transmission, and when the PDSCH transmission is performed in the CJT scheme, that further transmission is not performed in the CJT scheme. Thus, uplink and downlink transmissions in a unified TCI framework can be enhanced.

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

[0039] In this disclosure, some terms may refer to the same or similar physical meanings 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 to have the upper-layer parameter trs-Info" or "CSI-RS resource within NZP-CSI-RS-ResourceSet configured to have the upper-layer parameter trs-Info". The term "CSI-RS for channel measurement" may be used interchangeably with "a CSI-RS resource in an NZP-CSI-RS-ResourceSet that does not have the upper layer parameter trs-Info and is configured not to have upper layer parameter repetitions." The term "CSI-RS for beam measurement" may be used interchangeably with "CSI-RS resources in NZP-CSI-RS-ResourceSet configured to have upper layer parameter repeats." The term "QCL" may also mean that "two antenna ports are said to be pseudo-collocations if the large-scale characteristics of the channel from which symbols are transferred on one antenna port can be inferred from the channel from which symbols are transferred on the other antenna port. The large-scale characteristics include one or more of the following: delay spread, Doppler spread, Doppler shift, mean gain, mean delay, and spatial Rx parameters." The term "QCL parameter" may also mean "a large-scale characteristic that includes one or more of the following: delay spread, Doppler spread, Doppler shift, mean gain, mean delay, and spatial Rx parameter." The term "QCL reference for PDSCH, PDCCH, or CSI-RS" may also mean "a pseudo-collocation relationship between one or two downlink reference signals and the DM-RS port of a PDSCH, the DM-RS port of a PDCCH, or the CSI-RS port of a CSI-RS resource." The term "PDSCH CJT" may also mean "PDSCH transmitted using the CJT method." The terms "PDCCH, PUCCH, PUSCH" may also refer to "PDCCH, PUCCH, and PUSCH transmissions when PDSCH is transmitted using the CJT method." The term "DCI" may also mean "DCI Format 1_1 / 1_2" or "DCI Format 1_1 / 1_2 (with or without downlink (DL) assignment)". Since DCI Format 1_0 schedules common PDSCHs in most cases and does not include a TCI field, scheduled PDSCHs 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 indicator," "precoding matrix indicator," "TCI status," "transmit setting indicator," "quasi co-location (QCL)," "quasi co-location," "QCL parameter," "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-Control Resource Set Pool," "Multi-TRP," "Multi-TCI State," "Multi-TCI," "Multi-CORESET," and "Multi-Control Resource Set Pool," "MTRP," and "M-TCI," and "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” means an antenna array (having one or more antenna elements) available to a network device located at a specific geographical location. While some embodiments of this disclosure have been described with reference to multi-TRP scenarios (or single-TRP scenarios) as examples, these embodiments are for illustrative purposes only and are intended to help those skilled in the art understand and implement this disclosure, and do not imply any limitation on the scope of this disclosure. It should be understood that the contents of this disclosure described herein can be implemented in a variety of ways different from those described below. As used herein, the terms “network” / “network device” mean one or more network devices. Therefore, the terms “network,” “network device,” and “one or more network devices” may be used interchangeably. As used here, the QCL type may include the following types: - "typeA": {Doppler shift, Doppler spread, mean delay, delay spread} - "typeB": {Doppler shift, Doppler spread} - "typeC": {Doppler shift, mean delay} - "typeD": {spatial Rx parameter}.

[0040] Examples of communication environments Figure 1 shows an exemplary communication network 100 that can implement embodiments of the present disclosure. The communication network 100 includes a network device 120 and a terminal device 110. The network device 120 may include TRPs 131 to 134, and may provide services to the terminal device 110 via any of the TRPs 131 to 134.

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

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

[0043] Communication in the communication network 100 may conform to any appropriate 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, communication may be performed in accordance with any generation of communication protocol currently known or to be developed in the future. 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 network, 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 only and does not imply any limitation to the disclosure. The communication network 100 may include any suitable number of network devices and / or terminal devices and / or TRPs suitable for carrying out embodiments of the disclosure.

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

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

[0047] Recently, regarding the extension of the Unified TCI Framework, it has been agreed that up to two joint TCI states may be indicated and applied 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 to use up to two TCI states to provide QCL information for four TRPs.

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

[0050] The network may perform compensation based on the reported CJT CSI, which could potentially alter the large-scale characteristics of subsequent PDSCH CJTs. If the UE only records those characteristics from the most recent measurements of the reference signal, some inconsistencies may exist, potentially degrading PDSCH demodulation performance. In the worst case, the PDSCH CJT may fail. In other words, if the UE is unaware of network adjustments, it may have incorrect, outdated, or expired QCL assumptions.

[0051] More specifically, network compensation to support PDSCH CJT is for fine-syncing multiple TRPs, for example, to align the initial phase of the transmitted signal. Network compensation can be observed on the UE side to cause changes in the time domain and / or frequency domain of the signal, changes in the delay domain and / or Doppler domain of the signal, and signal delay adjustment, phase rotation, Doppler shift, and frequency adjustment.

[0052] Furthermore, problems may occur in other transmissions that do not use the CJT method. Figure 2B is a schematic diagram illustrating problems in other transmissions when a PDSCH transmission is performed in the CJT method, according to some exemplary embodiments of the present disclosure. As shown in Figure 2B, at timing T7, the UE may receive a scheduling for a PDSCH CJT via PDCCH. The scheduling may indicate one or more TCI states for the PDSCH CJT. At timing T8, the UE may begin applying the indicated one or more TCI states. However, the UE performs a PDSCH reception from the network via TRP1, TRP2, TRP3 and TRP4. Furthermore, the UE performs a PDCCH reception or a 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. Joint TCI states can further provide UL power control parameters and path loss references. However, only PDSCH can be transmitted in CJT mode. Up to two TCI states can be mapped to one TCI code point in the DCI for PDSCH CJT. Those TCI states may not provide appropriate QCL information and / or power control information for PDCCH / PUCCH / PUSCH and CSI-RS or SRS transmissions.

[0054] In view of the foregoing, embodiments of this disclosure provide communication solutions to overcome the above-mentioned problems and other potential problems. These solutions are described in detail below.

[0055] Example of implementing TCI configuration for PDSCH CJT In this embodiment, the TCI settings for PDSCH CJT are provided. The TCI settings will be described in relation to Figure 3.

[0056] Figure 3 is a schematic diagram showing a communication process 300 for setting up a TCI for a PDSCH CJT according to some exemplary embodiments of the present disclosure. For illustrative purposes, the process 300 will be described with reference to Figure 1.

[0057] Referring to Figure 3, the terminal device 110 may transmit UE capability information to the network device 120 (310). For example, the network device 120 may transmit radio resource control (RRC) settings related to the UE capability report to the terminal device 110. The terminal device 110 may report its capability to the network device 120 based on the RRC settings. 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 appropriate capability report is also possible.

[0058] Based on the UE capability report, the network device 120 may transmit the PDSCH CJT transmission method settings to the terminal device 110 (320). In some embodiments, the network device 120 may transmit the settings via an RRC message. Alternatively, or further, the network device 120 may enable PDSCH CJT using a medium access control 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), a component carrier (CC), or a bandwidth. In some embodiments, the configuration may be associated with a group of BWPs, CCs, or bandwidths. 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 for channel measurement (i.e., CSI-RS resource or resource set) 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, 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, qcl-Type2:CSI-RS resource 2 / CSI-RS resource set 2, type B. For examples 2, 3, and 4 above, additional UE capability reporting is required 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, the power control parameters for the UL power control setting may be set for PUCCH, PUSCH, and SRS transmissions for this TCI state. The identity (ID) of a reference signal (e.g., a CSI-RS setting or synchronization signal (SS) block) may be set for PUSCH path loss estimation for this TCI state.

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

[0064] In some embodiments, the network device 120 may configure a set of CSI-RS resources and a CSI report for PDSCH CJT. For example, the set of CSI-RS resources may include K_csi CSI-RS resources, for example, K_csi ≤ M_trp, where M_trp represents the number of TRPs selected by the terminal device 110 for 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 of length N_trp. In some examples, K_csi = N_trp.

[0065] In some embodiments, the network device 120 may configure a set of TRSs. For example, the set of TRSs may include M_trs TRSs, e.g., 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 each TRP. The terminal device 110 may measure each TRS and obtain a set of QCL parameters for each TRP. In some examples, M_trs = 1, transmitted collectively from multiple TRPs, and the multiple TRPs are transparent to the terminal device 110, and the terminal device 110 may measure this TRS and obtain QCL parameters for the equivalent transmission point or virtual transmission point. In some examples, one of the TRSs may be a reference TRS, transmitted from the reference TRP.

[0066] Optionally, the network device 120 may set, for example, based on UE capability reporting, the number and / or maximum number of TCI states that can be mapped to a single TCI code point, for example, {1,2} or {1,2,3,4}. 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, for each cell / BWP in which a PDSCH CJT is configured, the number and / or maximum number of TCI states that can be mapped to a single TCI code point may be configured separately. In some embodiments, for each cell / BWP in which a PDSCH CJT is configured, the number and / or maximum number of TCI states that can be mapped to a single TCI code point may be configured to be the same. In some embodiments, for each configured CORESET, the number and / or maximum number of TCI states that can be mapped to a single TCI code point may be configured separately. In some embodiments, for each configured CORESET except CORESET 0, the number and / or maximum number of TCI states that can be mapped to a single TCI code point may be configured to be the same.

[0068] Continuing to refer to Figure 3, the network device 120 may send a MAC CE to the terminal device 110 that activates a subset of TCI states in the list of TCI states (330). The MAC CE may further provide a mapping between TCI states and TCI code points 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 code point in the DCI for PDSCH CJT, the terminal device 110 may measure the DL RS of this TCI state and obtain QCL parameters for the equivalent or virtual transmit point.

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

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

[0072] In some embodiments, two TCI states DL RS may be set or transmitted with the same transmit power or the same power offset relative to a reference transmit power, for example, they may be set to have the same parameter powerControlOffsetSS value.

[0073] In some embodiments, the 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, the first TCI state is associated with a first delay, and the second TCI state is associated with a second delay. In this case, the terminal device 110 may assume that the delay applied to the PDSCH CJT is the maximum value, or the first and second delays. In another example, the first TCI state is associated with a first Doppler, and the second TCI state is associated with a second Doppler. In this case, the terminal device 110 may assume that the Doppler applied to 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, then 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] Examples of implementing PDSCH CJT within the unified TCI framework In this embodiment, a solution for PDSCH transmission in the CJT scheme is provided. This solution will be described with reference to Figure 4.

[0077] Figure 4 is a schematic diagram showing a communication process 400 for PDSCH transmission in a CJT scheme according to some exemplary embodiments of the present disclosure. For illustrative purposes, the process 400 will be described with reference to Figure 1.

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

[0079] In some embodiments, the capability of the terminal device 110 may include the duration of QCL parameter compensation. For example, the capability of the terminal device 110 may include the duration during which the terminal device 110 can acquire new QCL parameters based on QCL parameter compensation. In another example, the capability of the terminal device 110 may include the duration during which the terminal device 110 can apply QCL parameter compensation. In yet another example, the capability of the terminal device 110 may include the 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 Figure 4, the network device 120 may transmit a reference signal (for convenience, also referred to here as the first reference signal) as a QCL reference (420). 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 measurement.

[0081] Referring to Figure 4, the network device 120 may transmit CSI-RS for channel or interference measurement to the terminal device 110 (430). In one 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 for CSI-RS, terminal device 110 may report the CSI for PDSCH CJT to network device 120 (440). For example, a Type-II codebook and its improvements 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 may be used to determine the reference TRP. In yet another example, the selection of M_trp CSI-RS resources from K_csi CSI-RS resources or N_trp TRPs may be reported. If M_trp = N_trp is set 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 precise synchronization between TRPs to adjust the signals coherently transmitted from different TRPs. Compensation may be a method of adjustment for the time domain and / or frequency domain. Compensation may be a method of adjustment for one or more of the mean delay, delay spread, Doppler shift, and Doppler spread (in other words, QCL type A / B / C / D parameters). Compensation may be a method of adjustment for one or more of the phase shift and frequency shift. Compensation may be a method of adjustment for the transmit power. These are just examples, and it should be understood that network adjustments may depend on the implementation of the network.

[0084] Continuing with Figure 4, the network device 120 may transmit a DCI via the PDCCH to schedule a PDSCH CJT (460). The DCI indicates a set of TCI states. In some embodiments, the DCI may include a TCI field that notifies the terminal device 110 of the 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] Referring to Figure 4, the network device 120 may transmit QCL parameter compensation information for PDSCH CJT to the terminal device 110 (470). In some embodiments, the network device 120 may include the QCL parameter compensation information within the DCI. In this case, the terminal device 110 may obtain the QCL parameter compensation information from the DCI. It should be understood that the QCL parameter compensation information may be transmitted separately from the DCI.

[0086] In some embodiments, the QCL parameter compensation information may include compensation for time-domain parameters. In some embodiments, the QCL parameter compensation information may include compensation for frequency-domain parameters, such as frequency values ​​or frequency shifts. In some embodiments, the QCL parameter compensation information may include compensation for phase parameters, such as phase values ​​or phase shifts. In some embodiments, the QCL parameter compensation information may include compensation for delay parameters, such as average delay or delay spread. In some embodiments, the QCL parameter compensation information may include compensation for Doppler parameters, such as Doppler shift or 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 or not QCL parameter compensation has been applied. In some embodiments, the indication may include the exact value of the compensation applied. For example, for delay parameters, the indication may include X μs. For Doppler parameters, the indication may include X Hz. For phase parameters, the indication may include X degrees. For power parameters, 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 a single TCI code point in the DCI, QCL parameter compensation information may be provided via a second TCI state.

[0089] Based on the TCI state set and QCL parameter compensation information, terminal device 110 may receive PDSCH CJT (480).

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

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

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

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

[0094] In some embodiments, if the first reference signal is periodic or semi-permanent, the second set of reference signals may include another set of the first reference signals, i.e., another opportunity to transmit the first reference signal.

[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 (which for convenience may also be referred to here as the third set of reference signals). In some embodiments where the first set of reference signals is a set of periodic TRS signals, the third set of reference signals may be a set of aperiodic TRS signals. In some embodiments, the set of TCI states may be applied to the PDSCH CJT after the transmission of the latest additional reference signal following DCI reception.

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

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

[0098] For illustrative purposes, several exemplary embodiments will be described with reference to Figures 5A and 5B. Figure 5A is a schematic diagram showing 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] As shown in Figure 5A, terminal device 110 may receive TRS 1 from TRP 131 and TRS 2 from TRP 132 as QCL references. Terminal device 110 may also 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 transmit the CSI report to network device 120. Network device 120 may perform network adjustments. In this example, it is assumed that additional adjustments for TRP 132 are performed on mean delay, phase, Doppler shift, or frequency shift. Network device 120 may decide to perform PDSCH CJT using TRPs 131 and 132. The network device 120 may send a PDCCH to the terminal device 110 to schedule the PDSCH CJT, and then send the PDSCH CJT via TRPs 131 and 132.

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

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

[0102] As shown in Figure 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 adjustments. In this example, assume that additional adjustments for TRP 132 are performed on mean delay, phase, Doppler shift, or frequency shift. Network device 120 may decide to perform a 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 the modification to the example in Figure 5B above, if TRP 131 and TRP 133 are used for CJT, the additional RS may be TRS 3 for TRP 133, and the network device 120 may need to activate the TCI state for TRP 133 and deactivate the TCI state for TRP 132.

[0104] Other examples of transmission implementations within the unified TCI framework In this embodiment, a TCI state determination solution is provided for transmission without CJT. This solution will be described in relation to Figure 6.

[0105] Figure 6 is a schematic diagram showing a communication process 600 for determining the TCI for transmission without CJT, according to some exemplary embodiments of the present disclosure. For illustrative purposes, the process 600 will be described with reference to Figure 1.

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

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

[0108] Other details regarding the TCI setup for PDSCH CJT are similar to those described in relation to Figure 3, and therefore will not be repeated here for brevity.

[0109] Continuing with Figure 6, the network device 120 may send a DCI to the terminal device 110 via PDCCH to schedule a PDSCH CJT (620). This DCI indicates a set of TCI states. The operation in step 610 is similar to the operation in step 460 in Figure 4, and therefore will not be repeated here for brevity.

[0110] The terminal device 110 may determine which TCI state from the set of TCI states is to be used in a further transmission (630). When a 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 location 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, the terminal device 110 may receive an instruction from the network device 120 for a TCI state set for the further transmission (631). Thus, the TCI state for the further transmission may be separated from the TCI state for the PDSCH CJT. In other words, the TCI state for the PDSCH CJT is not applied to the further transmission.

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

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

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

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

[0117] In some embodiments, PDCCH reception may be separated from the TCI states for PDSCH CJT. In other words, the set of TCI states indicated for PDSCH CJT does not apply to PDCCH reception. In some embodiments, if CJT is enabled, an RRC setting may be used to inform terminal device 110 that none of the indicated TCI states may apply to CORESET. In some embodiments, terminal device 110 assumes, regardless of the RRC setting, that the TCI states or QCL assumptions for PDSCH CJT are not identical to any TCI states or QCL assumptions applied to CORESET used for DL ​​DCI reception. In some embodiments, terminal device 110 may expect a dedicated TCI state, a set TCI state, or an indicated TCI state for PDCCH. In some embodiments, terminal device 110 may report to network device 120 its ability, including information that the terminal device supports additional TCI state settings for PDCCH reception.

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

[0119] In some embodiments, several rules may be defined. For example, 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 PDSCH CJT, PDCCH is always transmitted with the QCL assumption of the first indicated joint TCI state. In yet another example, terminal device 110 may apply the first of two TCI states that maps to two TCI states and corresponds to the lowest TCI code point among the TCI code points applicable to PDSCH.

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

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

[0122] In some embodiments, the ratio of PDCCH EPRE to CSI-RS EPRE is indicated by network device 120, where 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 two or more TCI states are indicated for PDSCH CJT.

[0123] In some embodiments, the ratio of the PDCCH EPRE to the CSI-RS EPRE relates to the power offset between a dedicated DL-RS set as the QCL reference in the TCI state for the PDCCH and a CSI-RS set as the QCL reference in the TCI state corresponding to the reference / strongest TRP, or in the first indicated joint TCI state when two or more TCI states are indicated for the PDSCH CJT.

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

[0125] Embodiment 2 In this embodiment, for 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 compensation is not applied to the CSI-RS measurement.

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

[0127] In some embodiments, CSI-RS measurements may be separated from the TCI states for PDSCH CJT. In other words, the set of TCI states indicated for PDSCH CJT does not apply to CSI-RS measurements. In some embodiments, when CJT is enabled, RRC settings may be used to inform terminal device 110 that none of the indicated TCI states may apply to the CSI-RS resource or resource set. In some embodiments, regardless of the RRC settings, terminal device 110 may indicate that the TCI states or QCL assumptions for PDSCH CJT are not applicable. CSI-RSAssume that it is not identical to any TCI state or QCL assumption applicable to it. In some embodiments, terminal device 110 may expect that QCL information exists specifically for CSI-RS. In some embodiments, terminal device 110 may report to network device 120 its ability to support additional QCL information for CSI-RS on the same symbol.

[0128] In some embodiments, CSI-RS measurements may be at least partially associated with TCI states for PDSCH CJT on the same OFDM symbol. In other words, a set of TCI states shown for PDSCH CJT is applicable to CSI-RS on the same symbol. In some embodiments where additional information is provided to the terminal device 110, the terminal device 110 may select one of the shown TCI states. CSI-RS RRC settings may be used to indicate that they may be applied to. 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 to network device 120 its ability, including information that terminal device 110 supports the use of TCI state settings for PDSCH CJT for CSI-RS on the same symbol.

[0129] In some embodiments, several rules may be defined. For example, assume that the terminal device 110 uses the QCL of the reference / strongest TRP previously reported. 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 two TCI states that corresponds to the lowest TCI code point among the TCI code points that are mapped to two TCI states and are applicable to the PDSCH.

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

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

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

[0133] In some embodiments, UL transmissions may be separated from the TCI states for PDSCH CJT. In other words, the set of TCI states shown for 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 settings may be used to inform terminal device 110 that none of the shown 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 anticipate dedicated power control parameters and / or path loss reference signal information configured for PUCCH, PUSCH, or SRS, either individually or in combination. In some embodiments, terminal device 110 may report to network device 120 its ability to support additional power control parameters and / or path loss reference signal information for PUCCH, PUSCH, or SRS, either individually or in combination.

[0134] In some embodiments, a UL transmission may be associated at least partially with a TCI state for a PDSCH CJT. In other words, a set of TCI states indicated for a PDSCH CJT can provide power control parameters and / or path loss reference signal information for a PUSCH, PUCCH, or SRS transmission. In some embodiments where additional information is provided to the terminal device 110, an RRC setting may be used to inform the terminal device 110 that it may apply the 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 DL RS with the minimum path loss. In other words, we propose that the transmit power is determined based on the TCI state corresponding to the reference TRP, nearest TRP, or strongest TRP. The transmit power may be minimized by the power control parameter setting and 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 to the network device 120 its ability to support the use of the terminal device, including information about the terminal device that supports the use of the TCI state setting for PDSCH CJT to determine the power control parameter and / or path loss reference signal information for PUCCH, PUSCH, or SRS, individually or in combination.

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

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

[0138] Process 600 ensures that other transmissions are also executed correctly when PDSCH is executed in the CJT format. Processes 300 to 600 may be performed separately or in any appropriate combination.

[0139] Examples of implementation of the method Therefore, embodiments of this disclosure provide communication methods implemented in terminal devices and network devices. These methods will be described below with reference to Figures 7-8.

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

[0141] In block 710, terminal device 110 receives a DCI that schedules PDSCH transmission in the CJT scheme. The DCI indicates 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 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 the following: compensation for time-domain parameters, compensation for frequency-domain parameters, compensation for phase parameters, compensation for delay parameters, compensation for Doppler parameters, compensation for transmit power, or an indication of whether or not QCL parameter compensation is applicable.

[0144] In block 730, terminal device 110 receives PDSCH transmission based on the TCI state setting and QCL parameter compensation information.

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

[0146] In some embodiments, a first set of reference signals is received based on a set of TCI states at a first timing. In these embodiments, the terminal device 110 may receive a second set of reference signals based on a set of TCI states at a second timing later than the first timing, and determine a third set of QCL parameters based on a second measurement of 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 states at a first timing. In these embodiments, the terminal device 110 may receive a second set of reference signals based on a set of TCI states at a second timing later than the first timing, and determine a third set of QCL parameters based on a second measurement of the second set of reference signals. The terminal device 110 may then receive a PDSCH transmission based on the third set of QCL parameters and QCL parameter compensation information.

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

[0149] In some embodiments, the second set of reference signals may include one of the following: a set of DMRS for PDSCH transmission, another set of first 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 include at least one of the following: information supporting QCL parameter compensation, or the duration of QCL parameter compensation.

[0152] In some embodiments, the terminal device 110 may receive the PDSCH transmission after a certain duration following the reception of the DCI by applying information on the TCI state setting and QCL parameter compensation.

[0153] Method 700 allows PDSCH transmission in the CJT scheme to be well supported within the Unified TCI Framework.

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

[0155] In block 810, terminal device 110 This is a DCI that schedules PDSCH transmissions in the CJT scheme and receives a DCI that indicates a set of TCI states.

[0156] In block 820, terminal device 110 This determines which TCI states from the set of TCI states will be used in further transmissions, and when a PDSCH transmission is performed in the CJT manner, the subsequent transmission will not be performed in the CJT manner.

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

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

[0159] In some embodiments, the terminal device 110 may receive QCL parameter compensation information for PDSCH transmission and ensure that the QCL parameter compensation information is not applied to further transmissions.

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

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

[0162] Figure 9 is a schematic block diagram of a device 900 suitable for implementing an embodiment of the present disclosure. The device 900 can be considered as another exemplary embodiment of the terminal device 110 and network device 120 shown in Figure 1. Thus, the device 900 may be implemented in or as part of the terminal device 110 and network device 120.

[0163] As illustrated, the device 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 the 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 node referred to herein may actually have multiple antennas. The communication interface may represent any interface necessary 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, an 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 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 Figure 1. Embodiments of the present specification 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, a combination of the processor 910 and memory 920 may form 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, such as non-temporary computer-readable storage media, semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory, as non-limiting examples. Although only one memory 920 is shown in device 900, there may be several physically different memory modules in device 900. Processor 910 may be of any type suitable for a local technology network and may include, as non-limiting examples, one or more of general-purpose computers, dedicated computers, microprocessors, digital signal processors (DSPs), and processors based on multi-core processor architectures. Device 900 may have multiple processors, for example, application-specific integrated circuit chips that are temporally dependent on a clock that synchronizes the main processor.

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

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

[0168] As used herein, the term “circuit” may mean a hardware circuit and / or a combination of a hardware circuit and software. For example, a circuit may be a combination of an analog and / or digital hardware circuit and software / firmware. In yet another example, a circuit may be any part of a hardware processor having a digital signal processor, software and one or more memories, which work together to cause a device such as a terminal or 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 a part thereof that requires software / firmware for operation, but the software may not be present if it is not required for operation. As used herein, the term “circuit” also includes the implementation of a hardware circuit or one or more processors alone, or a part of a hardware circuit or one or more processors and their (or their) accompanying software and / or firmware.

[0169] In short, embodiments of this disclosure can provide the following solutions.

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

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

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

[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 a first measurement of the first set of reference signals, and receiving the PDSCH transmission based on the first set of QCL parameters and the QCL parameter compensation information.

[0174] In some embodiments, the terminal device receives the PDSCH transmission by determining a second set of QCL parameters by modifying a first set of QCL parameters based on the QCL parameter compensation information, and by 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 a 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 a set of TCI states at a second timing later than the first timing, determining a third set of QCL parameters based on a second measurement of 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 a 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 a set of TCI states at a second timing later than the first timing, determining a third set of QCL parameters based on a second measurement of the second set of reference signals, and receiving the PDSCH transmission based on the third set of QCL parameters and the QCL parameter compensation information.

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

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

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

[0180] In some embodiments, the terminal device further reports the capabilities of the terminal device, which include at least one of the following: information supporting the QCL parameter compensation, or the duration of the QCL parameter compensation.

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

[0182] In another solution, the terminal device includes a processor, which is configured to schedule a PDSCH transmission in the CJT scheme, receive the DCI indicating a set of TCI states, and determine which of the set of TCI states will be used in a further transmission, wherein when the PDSCH transmission is performed in the CJT scheme, the further transmission is not performed in the CJT scheme.

[0183] In some embodiments, the further transmission includes at least one of the following: a PDCCH transmission, a CSI-RS transmission at the same time-domain location 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 instruction for the TCI state set for further transmission, or by determining a predetermined TCI state from a 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 the TCI state that provides a downlink reference signal with the lowest path loss from the set of TCI states as the predetermined TCI state.

[0187] In some embodiments, the terminal device further receives information regarding QCL parameter compensation for the PDSCH transmission and ensures that the QCL parameter compensation information is not 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 setting indicating that the first TCI state provides reference information for the PDSCH transmission and 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 the following: average delay, delay spread, Doppler shift, Doppler spread, phase parameter, or transmit power parameter.

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

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

[0192] In an alternative solution, the method of communication includes scheduling a PDSCH transmission in the CJT scheme, receiving the DCI, which represents a set of TCI states, in a terminal device, and determining which of the set of TCI states is to be used in a further transmission, wherein the PDSCH transmission is performed in the CJT scheme, and the further transmission is not performed in the CJT scheme.

[0193] Overall, various embodiments of the Disclosure may be implemented in hardware or dedicated circuitry, software, logic, or any combination thereof. Some embodiments may be implemented in hardware, while others may be implemented in firmware or software that can be executed by a controller, microprocessor, or other computing device. Although various embodiments of the Disclosure are illustrated and described using block diagrams, flowcharts, or any other pictorial representation, it should be understood that any blocks, devices, systems, techniques, or methods described herein may be implemented, in non-limiting examples, in hardware, software, firmware, dedicated circuitry or logic, general-purpose hardware or controllers or other computing devices, or any combination thereof.

[0194] This disclosure further provides at least one computer program product tangibly stored on a non-temporary computer-readable storage medium. The computer program product includes computer-executable instructions, such as instructions contained in a program module, which are executed within a device on a target real or virtual processor to perform the processes or methods described above with reference to Figures 1 to 8. Generally, a program module includes routines, programs, libraries, objects, classes, components, data structures, etc., that perform a specific task or realize a specific abstract data type. In various embodiments, the functions of program modules may be combined or separated among program modules as needed. The machine-executable instructions of a program module may be executed within a local or distributed device. In a distributed device, program modules may reside in both local and remote storage media.

[0195] Program code for performing the methods of this 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 dedicated computer, or other programmable data processing device, and when executed by the processor or controller, the program code may implement the functions / operations specified in the flowcharts and / or block diagrams. The program code may run entirely on a machine, partially on a machine, as an independent software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0196] The program code described above may be implemented on a machine-readable medium, which may be any tangible medium that can contain or store programs used by or associated with an instruction execution system, device, or apparatus. 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, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or apparatus, or any suitable combination of the aforementioned mediums. More specific examples of machine-readable storage media may include electrical connections with one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disc read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the above.

[0197] While the operations have been described in a specific order, it should not be understood that, in order to obtain the desired results, these operations must be performed in the specific order shown, or in a sequential order, or that all of the described operations must be performed. In some cases, multitasking and parallel processing may be advantageous. Similarly, while some specific implementation details are included in the above discussion, these should not be interpreted as limitations on the scope of this disclosure, but rather as descriptions of features that may be specific to a particular embodiment. Some features described in the context of individual embodiments may be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may be implemented separately in multiple embodiments, or in any suitable subcombination.

[0198] While this disclosure has been described in language specific to structural features and / or methodological behavior, it should be understood that the disclosure as defined in the attached claims is not necessarily limited to the specific features or behaviors described above. Rather, the specific features and behaviors described above are disclosed as exemplary forms of implementing the claims.

Claims

1. Means for receiving first information from a network device, including the state of a first transmission configuration indicator (TCI) and a second TCI state for physical downlink shared channel (PDSCH) transmission, The system includes means for receiving from the network device a radio resource control (RRC) setting indicating one of the first TCI state and the second TCI state, which is applied to a first transmission including a physical downlink control channel (PDCCH) transmission or a channel state information-reference signal (CSI-RS) transmission, If the PDSCH transmission is using the coherent joint transmission (CJT) method, The QCL parameters for the second TCI state for the PDSCH transmission are different from the QCL parameters for the second TCI state for the first transmission. Terminal device.

2. If the PDSCH transmission is in the CJT format, The first TCI state and the second TCI state are of the same QCL type, and the same QCL type includes QCL type A. The terminal device according to claim 1.

3. The first TCI state provides information on the first Doppler shift, first Doppler spread, first mean delay, and first delay spread for the PDSCH transmission. The second TCI state provides information on the second average delay and the second delay spread for the PDSCH transmission. The terminal device according to claim 1.

4. Second information, including an instruction indicating whether delay parameter compensation is applied to the PDSCH transmission, is received from the network device. The terminal device according to claim 1.

5. The second information includes a compensation delay parameter for the PDSCH transmission, a compensation phase parameter for the PDSCH transmission, and a compensation frequency parameter for the PDSCH transmission. The terminal device according to claim 4.

6. Means for transmitting first information to a terminal device, including the state of a first transmission configuration indicator (TCI) and a second TCI state for physical downlink shared channel (PDSCH) transmission, The system includes means for transmitting to the terminal device a radio resource control (RRC) setting indicating one of the first TCI state and the second TCI state, which is applied to a first transmission including a physical downlink control channel (PDCCH) transmission or a channel state information-reference signal (CSI-RS) transmission, If the PDSCH transmission is using the coherent joint transmission (CJT) method, The QCL parameters for the second TCI state for the PDSCH transmission are different from the QCL parameters for the second TCI state for the first transmission. Network device.

7. If the PDSCH transmission is in the CJT format, The first TCI state and the second TCI state are of the same QCL type, and the same QCL type includes QCL type A. The network device according to claim 6.

8. The first TCI state provides information on the first Doppler shift, first Doppler spread, first mean delay, and first delay spread for the PDSCH transmission. The second TCI state provides information on the second average delay and the second delay spread for the PDSCH transmission. The network device according to claim 6.

9. Second information, including an instruction indicating whether delay parameter compensation is applied to the PDSCH transmission, is transmitted to the terminal device. The network device according to claim 6.

10. The second information includes a compensation delay parameter for the PDSCH transmission, a compensation phase parameter for the PDSCH transmission, and a compensation frequency parameter for the PDSCH transmission. The network device according to claim 9.

11. A method performed by a terminal device, Receiving first information from a network device, including the state of a first transmission configuration indicator (TCI) and a second TCI state for physical downlink shared channel (PDSCH) transmission, The process includes receiving from the network device a radio resource control (RRC) setting indicating one of the first TCI state and the second TCI state, which is applied to a first transmission that includes a physical downlink control channel (PDCCH) transmission or a channel state information-reference signal (CSI-RS) transmission, If the PDSCH transmission is using the coherent joint transmission (CJT) method, The QCL parameters for the second TCI state for the PDSCH transmission are different from the QCL parameters for the second TCI state for the first transmission. method.

12. If the PDSCH transmission is in the CJT format, The first TCI state and the second TCI state are of the same QCL type, and the same QCL type includes QCL type A. The method according to claim 11.

13. The first TCI state provides information on the first Doppler shift, first Doppler spread, first mean delay, and first delay spread for the PDSCH transmission. The second TCI state provides information on the second average delay and the second delay spread for the PDSCH transmission. The method according to claim 11.

14. A method performed by a network device, Transmitting first information to a terminal device, including the state of a first transmission configuration indicator (TCI) and a second TCI state for physical downlink shared channel (PDSCH) transmission, The method includes transmitting to the terminal device a radio resource control (RRC) setting indicating one of the first TCI state and the second TCI state, which is applied to a first transmission that includes a physical downlink control channel (PDCCH) transmission or a channel state information-reference signal (CSI-RS) transmission, If the PDSCH transmission is using the coherent joint transmission (CJT) method, The QCL parameters for the second TCI state for the PDSCH transmission are different from the QCL parameters for the second TCI state for the first transmission. method.

15. If the PDSCH transmission is in the CJT format, The first TCI state and the second TCI state are of the same QCL type, and the same QCL type includes QCL type A. The method according to claim 14.

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