User device and method thereof

Abstract

The embodiments of the present disclosure relate to a method, an apparatus, and a computer-readable medium for communication. The method implemented in a terminal device includes, in response to switching to a second frequency portion, determining a time interval during which the terminal device uses a first reference signal received from a network device on a first frequency portion as a Quasi Co-location (QCL) reference signal. The terminal device performs communication with the network device before the time interval ends based on a first set of properties obtained by measuring at least the first reference signal. The method also includes obtaining a second set of properties within the time interval by measuring a second reference signal received from the network device on the second frequency portion, where the second reference signal and the first reference signal have a first identity. The method also includes, after the time interval, performing communication with the network device on the second frequency portion using the second reference signal as the QCL reference signal based on the second set of properties.

Description

[Technical field]

[0001] TECHNICAL FIELD Embodiments of the present disclosure relate generally to the field of telecommunications, and more particularly to communication methods, apparatus, and computer-readable media. [Background technology]

[0002] Cross component carrier (CC) beam indication or cross bandwidth part (BWP) beam indication is supported from Release 15 via the transmission configuration indicator (TCI) state. The TCI state contains an information element (IE) of the quasi co-location-Info (QCL) containing the CC identity (ID) or BWP ID of the cell field or the bwp-Id field. If this field is not present, the TCI state applies to the serving cell for which it is configured.

[0003] In Release 17, the TCI state pool was introduced to avoid double signaling. If there is no CC ID or BWP ID for a QCL-Type A or D source reference signal (RS) in the QCL-Info of a TCI state, the terminal device shall assume that the QCL-Type A or D source RS is in the BWP or CC to which the TCI state applies.

[0004] Additionally, BWP or CC switching is supported. Immediately after BWP or CC switching, the terminal cannot obtain the large scale property from the indicated TCI state if there is a QCL-Type A or D source RS in the BWP or CC to which the TCI state applies, if the BWP ID or CC ID is not configured for the RS. Summary of the Invention [Problem to be solved by the invention]

[0005] Generally, the exemplary embodiments of the present disclosure provide a communication method, apparatus, and computer-readable medium. [Means for solving the problem]

[0006] In a first aspect, a method for communication implemented in a terminal device is provided. The method includes, in response to switching to a second frequency portion, determining a time interval during which the terminal device uses a first reference signal received from a network device on a first frequency portion as a Quasi Co-location (QCL) reference signal. The terminal device performs communication with the network device before the time interval ends based on a first set of properties obtained by measuring the first reference signal. The method also includes obtaining a second set of properties within the time interval by measuring a second reference signal received from the network device on the second frequency portion. Both the second reference signal and the first reference signal have a first identity. The method also includes, after the time interval, performing communication with the network device on the second frequency portion using the second reference signal as the QCL reference signal based on the second set of properties.

[0007] In a second aspect, a method for communication implemented in a network device is provided. The method includes determining a time interval during which a terminal device uses a first reference signal transmitted by the network device on a first frequency part as a QCL reference signal in response to switching to a second frequency part, and the terminal device performs communication with the network device before the time interval ends based on a first set of properties obtained by measuring the first reference signal. The method also includes transmitting a second reference signal to the terminal device on the second frequency part after the start of the time interval. Both the second reference signal and the first reference signal have a first identification. The method also includes performing communication with the terminal device on the second frequency part after the time interval using the second reference signal as the QCL reference signal.

[0008] In a third aspect, there is provided a terminal device comprising a processor and a memory storing instructions, the memory and the instructions configured to cause the terminal device, using the processor, to perform a method according to the first aspect.

[0009] In a fourth aspect there is provided a network device comprising a processor and a memory storing instructions configured to, using the processor, cause the network device to perform a method according to the second aspect.

[0010] In a fifth aspect, there is provided a computer readable medium storing instructions which, when executed on at least one processor of an apparatus, cause the apparatus to perform a method according to the first aspect.

[0011] In a sixth aspect, there is provided a computer readable medium storing instructions which, when executed on at least one processor of an apparatus, cause the apparatus to perform a method according to the second aspect.

[0012] It should be understood that this summary is not intended to identify key or essential features of the embodiments of the present disclosure, nor to limit the scope of the present disclosure. Other features of the present disclosure will be readily apparent from the following description. [Brief description of the drawings]

[0013] The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description of several embodiments of the present disclosure in the accompanying drawings.

[0014] [Figure 1] FIG. 1 illustrates an exemplary communications network in which embodiments of the present disclosure may be implemented.

[0015] [Diagram 2] FIG. 1 is a diagram showing an example of BWP switching or CC switching in the prior art.

[0016] [Diagram 3] FIG. 2 is an example signaling diagram illustrating an example process for frequency part switching in accordance with some embodiments of the present disclosure.

[0017] [Figure 4A] FIG. 2 illustrates an example format of a Media Access Control Control Element (MAC CE) activation command in accordance with some embodiments of the present disclosure. [Figure 4B] FIG. 2 illustrates an example format of a Media Access Control Control Element (MAC CE) activation command in accordance with some embodiments of the present disclosure. [Figure 4C] FIG. 2 illustrates an example format of a Media Access Control Control Element (MAC CE) activation command in accordance with some embodiments of the present disclosure.

[0018] [Diagram 5] FIG. 2 illustrates an example of BWP switching or CC switching according to some embodiments of the present disclosure.

[0019] [Figure 6A] FIG. 13 illustrates an example of BWP switching or CC switching according to some other embodiments of the present disclosure.

[0020] [Figure 6B] FIG. 13 illustrates an example of BWP switching or CC switching according to some other embodiments of the present disclosure.

[0021] [Figure 7] FIG. 13 is a diagram showing an example of BWP switching or CC switching according to yet another embodiment of the present disclosure.

[0022] [Figure 8] FIG. 13 is a diagram showing an example of BWP switching or CC switching according to yet another embodiment of the present disclosure.

[0023] [Figure 9] 1 is a flowchart of an exemplary method according to some embodiments of the present disclosure.

[0024] [Figure 10] 4 is a flowchart of an exemplary method according to some alternative embodiments of the present disclosure.

[0025] [Figure 11] FIG. 1 is a schematic block diagram of an apparatus suitable for implementing embodiments of the present disclosure.

[0026] In the drawings, the same or similar reference numbers represent the same or similar elements. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] The principles of the present disclosure will now be described with reference to some exemplary embodiments. It should be understood that these embodiments are provided for illustrative purposes only, to assist those skilled in the art in understanding and implementing the present disclosure, and do not imply any limitations on the scope of the present disclosure. The disclosure described herein can be implemented in various ways different from those described below.

[0028] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0029] 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 (PDAs), portable computers, tablets, wearable devices, internet of things (IoT) devices, Ultra-reliable and Low Latency Communication (URLLC) devices, Internet of Everything (IoE) devices, machine type communication (MTC) devices, vehicle-mounted devices for V2X communications where X means pedestrian, vehicle, or infrastructure / network, devices for Integrated Access and Integrated Access and Backhaul (IAB), satellite- or airborne vehicles in a Non-terrestrial network (NTN) including High Altitude Platforms (HAPs) including satellites and Unmanned Aircraft Systems (UASs), Augmented Reality (AR), Mixed Reality (MR), and other applications. These include, but are not limited to, extended reality (XR) devices that include different types of reality, such as virtual reality (VR), unmanned aerial vehicles (UAVs), which are aircraft without a human pilot and are commonly referred to as drones, devices on high speed trains (HSTs), image acquisition devices such as digital cameras, sensor game devices, music storage and playback devices, or Internet appliances that enable wireless or wired Internet access and browsing.The "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, over-the-air software distribution, group communication and IoT applications. It may also incorporate one or more Subscriber Identity Modules (SIMs), known as multi-SIMs. The term "Terminal Equipment" may be used interchangeably with UE, mobile station, subscriber station, mobile terminal, user terminal, or wireless device.

[0030] The term "network device" as used herein means a device capable of providing or hosting a cell or coverage in which a terminal device can communicate. Examples of network devices include, but are not limited to, a Node B (NodeB or NB), an evolved Node B (eNodeB or eNB), a next generation Node B (gNB), a transmission reception point (TRP), a remote radio unit (RRU), a radio head (RH), a remote radio head (RRH), an IAB node, a femto node, a pico node, a low power node such as a reconfigurable intelligent surface (RIS), etc.

[0031] The terminal device or network device may have the capability of artificial intelligence (AI) or machine learning. Generally, it includes a model trained from a large amount of data collected for a specific function and can be used to predict some information.

[0032] The terminal device or network device may operate on several frequency ranges, such as FR1 (410 MHz-7125 MHz), FR2 (24.25 GHz-71 GHz), frequency bands greater than 100 GHz, and Tera Hertz (THz). It can also operate on licensed / unlicensed / shared spectrum. The terminal device may have two or more connections with the network device under Multi-Radio Dual Connectivity (MR-DC) application scenarios. The terminal device or network device can operate in full duplex, flexible duplex, and cross division duplex modes.

[0033] Embodiments of the present disclosure may be implemented in test equipment, such as, for example, a signal generator, a signal analyzer, a spectrum analyzer, a network analyzer, a test terminal equipment, a test network equipment, a channel emulator, and the like.

[0034] As used herein, the singular forms "a," "an," and "said" include the plural forms unless the context clearly indicates otherwise. The term "comprises" and variations thereof should be understood as open-ended terms meaning "including, but not limited to." The term "based on" should be understood as "based at least in part on." The terms "some embodiments" and "embodiments" should be understood as "at least some embodiments." The term "another embodiment" should be understood as "at least one other embodiment." Terms such as "first," "second," and the like may refer to different or the same object. The following may include other explicit and implicit definitions.

[0035] In some instances, values, procedures, or devices are referred to as "best," "lowest," "highest," "minimum," "maximum," etc. It should be understood that such descriptions are intended to illustrate that selections can be made from among many functional alternatives used, and that such selections are not necessarily better, smaller, higher, or otherwise more preferred than other selections.

[0036] In the following, the terms "PUSCH transmission", "PUSCH transmission occasion", "uplink transmission", "PUSCH repetition", "PUSCH occasion" and "PUSCH reception" may be used interchangeably. The terms "transmission", "transmission occasion" and "repetition" may be used interchangeably. The terms "precoder", "precoding", "precoding matrix", "beam", "spatial relationship information", "spatial relationship info", "TPMI", "precoding information", "precoding information and layer number", "precoding matrix indicator (PMI)", "precoding matrix indicator", "transmit precoding matrix support", "precoding matrix indication", "TCI state", "transmission configuration indicator", "quasi co-location (QCL)", "quasi-co-location", "QCL parameters" and "spatial relationship" may be used interchangeably. The terms "SRI", "SRS resource set index", "UL TCI", "UL spatial domain filter", "UL beam", "combined TCI" may be used interchangeably. The terms "QCL Reference", "QCL Source", "QCL Reference RS", "QCL Source RS", and "QCL RS" may be used interchangeably. The terms "BWP / CC", "BWP", "CC", "carrier", "SCell", "cell", "serving cell", "cell group", and "physical cell" may be used interchangeably. The terms "Release 17", "r17", and "Rel 17" may be used interchangeably.

[0037] FIG. 1 illustrates an exemplary communication network 100 in which embodiments of the present disclosure may be implemented. The network 100 includes a terminal device 110 and a network device 120 serving the terminal device 110. The serving area of ​​the network device 120 is referred to as a cell 102. It should be understood that the number of network devices and terminal devices is given for illustrative purposes only and no limitation is implied. The system 100 may include any suitable number of network devices and terminal devices suitable for implementing embodiments of the present disclosure. Although not shown, it should be understood that one or more terminal devices may be within the cell 102 and be served by the network device 120.

[0038] Communications within communication network 100 may be accomplished according to any generation of communication protocols now known or 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) communication protocols, 5.5G, 5G-Advanced networks, or sixth generation (6G) networks.

[0039] As mentioned above, cross CC beam indication or cross BWP beam indication is supported via TCI state from Release 15 onwards. The TCI state includes a QCL Info IE that includes the CC ID or BWP ID of the cell or bwp-Id field. For example, the TCI-State IE may include the following information: TCI-State ::= SEQUENCE { tci-StateId TCI-StateId, qcl-Type QCL-Info, qcl-Type2 QCL-Info OPTIONAL, -- Need R ... } QCL-Info ::= SEQUENCE { cell ServCellIndex OPTIONAL, -- Need R bwp-Id BWP-Id OPTIONAL, -- Cond CSI-RS-Indicated referenceSignal CHOICE { csi-rs NZP-CSI-RS-ResourceId, ssb SSB-Index }, qcl-Type ENUMERATED {typeA, typeB, typeC, typeD}, ... }

[0040] Table 1 shows the description of the QCL-Info field. [Table 1]

[0041] An RS from another CC may be configured as a QCL Type C or Type D source RS by setting both the CC ID and the RS ID. A QCL Type A or Type B source RS must be located in the serving cell as the target RS, i.e. cross-CC is not supported. If the CC ID is not present, the CC ID is the CC ID for which this TCI state is set.

[0042] From Release 17, the TCI state pool may be configured in a reference BWP or CC and can be shared by other BWPs or CCs with reference links to the reference BWP or CC, which can reduce a lot of signaling redundancy. If no BWP ID or CC ID exists, this BWP ID or CC ID of the RS is the BWP ID or CC ID for which this TCI state applies. The target RS, i.e. the QCL type A or B source RS, must be located in the serving cell, since cross-CC is still not supported.

[0043] Additionally, BWP or CC switching is supported. Immediately after BWP or CC switching, the terminal cannot obtain the large scale property from the indicated TCI state if there is a QCL-Type A or D source RS in the BWP or CC to which the TCI state applies, if the BWP ID or CC ID is not configured for the RS. BWP or CC switching causes the problem that the BWP / CC ID+RS ID points to an RS in the second BWP or CC, but the terminal has not performed measurements in the second BWP or CC. Therefore, the terminal cannot receive DL transmissions using the RS as QCL reference. This is explained with reference to FIG. 2.

[0044] FIG. 2 illustrates an example 200 of BWP or CC switching in the prior art. As illustrated, in a normal case 200A, the terminal device receives RSs 211-1, 211-2, 211-3, and 211-4 from a network device in a first BWP or first CC (also referred to as a first BWP / CC). It should be understood that the transmissions of RSs 211-1 to 211-7 may be multiple transmissions of a single RS, for example, periodic transmissions of the single RS. The terminal device receives a physical downlink control channel (PDCCH) 212 in the first BWP / CC, which schedules a physical downlink shared channel (PDSCH) 213. Based on a QCL relationship 214 indicated in a TCI state included in the PDCCH 212, the terminal device 110 receives the PDSCH 213.

[0045] It should be noted that cross BWP / CC QCL-Type A relationship is not yet supported. This means that the tracking RS and the PDCCH / PDSCH demodulation reference signal (DMRS) should be in the same BWP / CC. Therefore, one reasonable configuration may be that there is always no BWP / CC ID for the source RS of QCL-Type A. This kind of configuration indeed has some advantages. For example, it can reduce the required number of TCI states to be configured and avoid redundant TCI state activation signaling.

[0046] However, when considering BWP / CC switching, particularly in the case of dynamic switching, one problem can be identified, which is explained with reference to problem case 200B in FIG.

[0047] In the problematic case 200B, the terminal device receives a physical downlink control channel (PDCCH) 222 that schedules a physical downlink shared channel (PDSCH) 223 in a second BWP or a second CC (also referred to as a second BWP / CC). The ID+RS ID of the second BWP / CC refers to RSs 231-1, 231-2, and 231-3 in the second BWP / CC. It should be understood that the transmissions of RSs 231-1 to 231-3 may be multiple transmissions of a single RS, for example, periodic transmissions of the single RS. Immediately after the BWP switch or CC switch, the terminal device cannot obtain the large scale properties of RSs 231-1, 231-2, and 231-3 because the terminal device has not performed measurements in the second BWP or CC. Therefore, the terminal device cannot use RSs 231-1, 231-2 and 231-3 as QCL references to receive PDSCH 223. In other words, if there is no BWP / CC ID for the QCL-Type A source RS in the QCL-Info in the TCI state, the terminal device may not be able to obtain measurement results from the QCL-Type A source RS immediately after a BWP / CC switch.

[0048] It should be understood that the dashed arrows in FIG. 2 do not represent actual transmissions or measurements.

[0049] To solve the above problem and one or more other potential problems, an embodiment of the present disclosure provides a solution for frequency part switching. According to the solution, in response to switching to a second frequency part, the terminal device determines a time interval during which the terminal device uses a first RS received from a network device in a first frequency part as a QCL source RS. Before the time interval ends, the terminal device performs communication with the network device based on a first set of properties by measuring at least the first RS. The terminal device obtains a second set of properties within the time interval by measuring at least a second RS received from the network device in a second frequency part. Both the second RS and the first RS have a first identity. After the time interval, the terminal device performs communication with the network device in the second frequency part based on the second set of properties using the second RS as a QCL source RS. In this way, the terminal device is given enough time to measure a new RS identified by the identity of the second frequency part and the identity of the RS.

[0050] The principles of the present disclosure will now be described with reference to Figures 3-10. Reference is now made to Figure 3, which illustrates a signaling diagram illustrating a process 300 for frequency portion switching in accordance with some exemplary embodiments of the present disclosure. For illustrative purposes, the process 300 will be described with reference to Figure 1. The process 300 may involve a terminal device 110 and a network device 120 as shown in Figure 1. Although the process 300 has been described with reference to the communications network 100 of Figure 1, the process may be applied to other communications scenarios as well.

[0051] As shown in FIG. 3, terminal device 110 switches (340) to a second frequency portion.

[0052] In some embodiments, the terminal device 110 may switch from a first frequency portion to a second frequency portion. In some embodiments, the terminal device 110 may switch from a frequency portion other than the first frequency portion and the second frequency portion to the second frequency portion. In some embodiments, each of the first frequency portion and the second frequency portion may be a BWP or a CC. In some embodiments, each of the first frequency portion and the second frequency portion may be a carrier, a cell, a physical cell, a cell group, a band, or a band combination.

[0053] In some embodiments, the first frequency portion may be one of: an active BWP before a BWP switch, an active CC before a CC switch, a BWP or CC to which scheduling information is transmitted, a BWP or CC with a TCI-State set, a BWP or CC with a Release 17 TCI-State set, a BWP or CC with one or more TCI state pools set, a reference BWP or reference CC, a default BWP or default CC, an initial downlink or uplink BWP, or an initial downlink or uplink CC.

[0054] In an embodiment in which each of the first and second frequency parts is a BWP or a CC, switching from one frequency part to another frequency part is also referred to as a BWP / CC switching. For illustrative purposes, the embodiments of the present disclosure will be described with a BWP / CC as an example of the first and second frequency parts. Of course, the present disclosure may also be applied to switching of frequency parts other than a BWP / CC switching.

[0055] In some embodiments, the BWP switching may be based on a timer. This timer may be the bwp-InactivityTimer. In some other embodiments, the BWP switching may be based on a dynamic indication. For example, the BWP switching may be based on a bandwidth part indicator in the DCI.

[0056] The terminal device 110 does not need to transmit uplink (UL) signals or receive downlink (DL) signals during the switching delay.

[0057] In some embodiments, CC switching may be based on a timer. This timer may be sCellDeactivationTimer. In some embodiments, CC switching may be based on configuration or reconfiguration via radio resource control (RRC) signaling. Additionally, CC switching may dynamically activate or deactivate CCs via MAC CE. CC switching may also be cross-carrier scheduling between activated CCs via carrier indicators in the DCI.

[0058] In some embodiments, a set time interval for switching may be set, T switch This set time interval may be expressed as T BWPswitchdelay This set time interval may include a switching delay for the BWP switching, which may be represented by T CCswitchdelay The set time interval may include a switching delay for a CC switching, which may be represented by n+T switch The terminal 110 does not need to transmit any UL signal or receive any DL signal during the switchover, where n represents the starting slot when the terminal 110 learns of the switchover. For example, the terminal 110 learns of the switchover by receiving, decoding, or acknowledging a BWP / CC switchover command.

[0059] In some embodiments, optionally, before the switchover, terminal device 110 may receive configuration information from network device 120 (310).

[0060] In some embodiments, this configuration information may include a TCI state pool configuration. In some embodiments, this configuration information may be configured per CC configuration, per band combination, per band or CC group, or per CC or BWP.

[0061] In some embodiments, the configuration information may include at least one of: a starting slot when the terminal device 110 becomes aware of the switch, a configured time interval for the switch, a periodicity of the second RS, a configured number of transmission occasions for the second RS, a QCL type of the second RS, numerology information of the second RS, or a predefined capability-related value of the terminal device 110.

[0062] In an embodiment in which the configuration information includes a TCI state pool configuration, the TCI state pool configuration may include the following information: TCI state pool (optional) tciStatePoolId (optional) List of TCI-State-r17 list of {cell (optional) + bwp-Id (optional) + tci-State_r17} TCI-State-r17 tci-StateId_r17 tci-StateType (optional) qcl-Type1: QCL-Info-r17 qcl-Type2: QCL-Info-r17 (if configured) QCL-Info-r17 cell (optional) bwp-Id (optional) referenceSignal choice of { NZP-CSI-RS-ResourceId (CSI-RS for beam management or CSI-RS for tracking, used for DL / UL TCI or Joint TCI state); SSB-Index; SRS ResourceId (SRS for beam management, used for UL TCI); } qcl-Type ENUMERATED{typeA, typeB, typeB, typeD} pathloss RS (optional) choice of{ SSB-Index; NZP-CSI-RS-ResourceId (periodic CSI-RS); }

[0063] TCI-State-r17 may be referred to as Release 17 TCI State. QCL-Info-r17 may be referred to as Release 17 QCL-Info. Table 2 shows the descriptions of the TCI-State-r17 and QCL-Info-r17 fields. [Table 2]

[0064] Note that the BWP / CC ID of a TCI state in the TCI state pool is different from the BWP / CC ID of the RS. If there is no BWP / CC ID of a TCI state in the TCI state pool, the configured BWP / CC ID or the scheduling / scheduled / applied BWP / CC ID is assumed.

[0065] It should also be noted that one plausible example for the BWP / CC ID of an RS is: no BWP / CC ID is set for QCL type A / B / C source RS and a tracking RS should be placed per BWP / CC, significantly reducing the number of required TCI states; a BWP / CC ID is set for QCL type D source RS and points to the BWP / CC for beam management, so that the same receive (transmit if UL) beam is applied across the BWP / CC.

[0066] Also, it should be noted that for other CC / BWPs that do not have a dedicated TCI state pool configuration, the BWP / CC ID may be linked to a CC / BWP that is configured to have a TCI state pool.

[0067] In some embodiments, optionally, prior to the switchover, the terminal device 110 may receive (320) a DCI or MAC CE activation command from the network device 120. The DCI or MAC CE activation command includes a TCI state indication. A TCI state identification (ID) in the TCI state indication points to a TCI state in the TCI state pool.

[0068] In some embodiments, the conventional format of the MAC CE activation command as shown in Figures 4A, 4B, and 4C may be reused with the following modifications. For example, if the reference BWP / CC is known (e.g., via RRC configuration), and only one TCI state pool is configured in the reference BWP / CC, the terminal device 110 may use the (serving cell ID and BWP ID) indicated in the conventional MAC CE command to find the reference BWP / CC via the configured link between the BWP / CCs. In some embodiments, the MAC CE activation command may activate the TCI state in all linked BWP / CCs. In some embodiments, the MAC CE activation command may activate the TCI state in all linked active BWP / CCs. Additionally, in Figure 4A, Ti may be the order (i-th or (i+1)-th) of the TCI state in the configured TCI state list via the TCI state pool configuration. In Figures 4B and 4C, the TCI state ID refers to the TCI state in the TCI state pool, not the TCI state configured in the BWP / CC with the indicated (serving cell ID+BWP ID).

[0069] Additionally, the TCI states may be grouped into multiple subsets, with the TCI states in each subset associated with a different physical cell ID (PCI). For example, the TCI states associated with the serving cell may be grouped into a first subset, and the TCI states associated with non-serving cells (i.e., with a different PCI than the serving cell) may be grouped into a second subset. In some embodiments, the TCI state activation is based on the order of the TCI states in the first subset and the order of the TCI states in the second subset. In other embodiments, the TCI state activation is based on the order of the TCI states associated with the serving cell's PCI and the order of the TCI states associated with different PCIs.

[0070] Optionally, a MAC CE activation command as shown in Figure 4A can be used to activate the TCI state that applies to at least the terminal device dedicated channel / RS, and a MAC CE activation command as shown in Figure 4B can be used to activate the TCI state that applies to non-dedicated channels / RS, e.g., common PDCCH. In some embodiments, when a MAC CE activation command as shown in Figure 4B is used to indicate the TCI state for the PDCCH, the corresponding PDCCH includes a TCI field that points to the Release 15 / 16 TCI state only for the scheduled PDSCH. In some embodiments, when a MAC CE activation command as shown in Figure 4A indicates the TCI state for the PDCCH (i.e., Release 17, common TCI), the corresponding PDCCH includes a TCI field that points to the Release 17 TCI state for all channels / RS for which the indicated TCI state applies, including at least one of the terminal device dedicated PDCCH / PDSCH, terminal device dedicated PUCCH / PUSCH.

[0071] In other embodiments, the new format of the DCI or MAC CE activation command for the PDCCH may include at least one of {TCI state pool ID, BWP / CC ID, TCI state ID}. In some embodiments, the DCI or MAC CE activation command may activate the TCI state in the indicated BWP / CC. In some embodiments, if the reference BWP / CC is known (e.g., via RRC configuration), and only one TCI state pool is configured in the reference BWP / CC, the terminal device 110 may use the (serving cell ID and BWP ID) indicated in the DCI or MAC CE command to find the reference BWP / CC via the configured link between the BWP / CCs. In some embodiments, the DCI or MAC CE activation command may activate the TCI state in all linked BWP / CCs. In some embodiments, the DCI or MAC CE activation command may activate the TCI state in all linked active BWP / CCs.

[0072] 3, in some embodiments, optionally, prior to switching, terminal device 110 may obtain a first set of properties by measuring at least a first RS (330). Terminal device 110 may record the obtained first set of properties.

[0073] In some embodiments, the first RS may be identified by a first frequency part ID and an RS ID, for example, the first RS may be identified by a first BWP / CC ID+RS ID.

[0074] In some embodiments, the RS ID may be the ID of the RS in the QCL-Info of the TCI state for at least one of the following: - Type A / B / C RS only, - In addition, Type D RS, - plus the path loss RS.

[0075] In some embodiments, the first BWP / CC ID may be an ID for one of the following: - the active BWP / CC before the BWP / CC switch, - BWP / CC to which scheduling information is sent, - BWP / CC with TCI-State set, - BWP / CC with TCI-State set to Release 17, - BWP / CC with TCI state pool configured, - Reference BWP / CC, - Default BWP / CC (e.g. BWP / CC with a specific ID, such as min / max ID), - Initial DL / UL BWP / CC.

[0076] 3, in response to the switch, the terminal device 110 determines (350) a time interval during which the terminal device 110 uses the first RS received from the network device 120 in the first frequency portion as the QCL RS. Before the time interval expires, the terminal device 110 performs communication with the network device 120 based on the first set of properties by measuring the first RS.

[0077] In some embodiments, terminal device 110 may determine a start slot (denoted by n as described above) when the terminal learns of the switch based on configuration information received from network device 120. Terminal device 110 may also determine a configured time interval for the switch (T as described above) based on the configuration information. switch The terminal device 110 may determine a QCL time interval for acquiring the second set of properties. In the following, the QCL time interval for acquiring the second set of properties is represented as T QCL Then, the terminal device 110 may determine this time interval based on at least one of the starting slot, the configured time interval for switching, and the QCL time interval.

[0078] In some embodiments, the QCL time interval T QCL may be related to the periodicity of the second RS. For example, the QCL time interval T QCL may be N times the periodicity of the second RS, and the end of the time interval means after the Nth transmission occasion or the Nth measurement occasion of the second RS after the BWP / CC switch. In some embodiments, N may be determined based on configuration information from the network device 120, the capabilities of the terminal device 110, or standard requirements.

[0079] In some embodiments, the QCL time interval T QCL may be related to the QCL type of the second RS. For example, the QCL time interval T QCL may be N1 for type A, N2 for type B, N3 for type C, N4 for type D, and N5 for path loss RS.

[0080] In some embodiments, the QCL time interval T QCL may be related to a numerology such as subcarrier spacing (SCS).

[0081] In some embodiments, the QCL time interval T QCL may be a set value, a predefined value, or a value related to the capabilities of the terminal device 110.

[0082] Upon determining the time interval, the terminal device 110 obtains (360) a second set of properties within the time interval by measuring at least a second reference signal received from the network device 120 in a second frequency portion. The first RS and the second RS have a first identity (ID). Hereinafter, the first ID may also be referred to as a first RS ID. In some embodiments, the first RS and the second RS may have different identities. In other words, the first RS and the second RS have different RS IDs. In some embodiments, when the first RS and the second RS have different RS IDs, the terminal device 110 obtains (360) a second set of properties within the time interval by measuring at least the second RS received from the network device 120 in the second frequency portion and determining a time interval during which the terminal device uses the first reference signal received from the network device in the first frequency portion as a quasi-co-location (QCL) reference signal in response to switching to the second frequency portion, and the terminal device performs communication with the network device before the time interval expires based on the first set of properties obtained by measuring at least the first reference signal, and the first reference signal and the second reference signal have different RS IDs.

[0083] In some embodiments, the first RS and the second RS may be RSs of the same QCL type. For example, the first RS and the second RS may be RSs of QCL type A, QCL type B, or QCL type C. For the sake of explanation, QCL type A, QCL type B, and QCL type C may also be referred to as QCL type A / B / C.

[0084] In some embodiments, terminal device 110 may obtain the second set of properties by: Terminal device 110 may determine a QCL type of the second RS based on configuration information received from network device 120. Terminal device 110 may then determine the second set of properties based on the QCL type by measuring the second RS in a second frequency portion.

[0085] In some embodiments, the terminal device 110 may determine the second set of properties based on the OCL type by: If the QCL type is QCL type A, the terminal device 110 may determine the Doppler shift, Doppler spread, average delay, and delay spread based on the measurement results of the second RS; If the QCL type is QCL type B, the terminal device 110 may determine the Doppler shift and Doppler spread based on the measurement results of the second RS; If the QCL type is QCL type C, the terminal device 110 may determine the Doppler shift and average delay based on the measurement results of the second RS; If the QCL type is QCL type D, the terminal device 110 may determine the spatial Rx parameters based on the measurement results of the second RS.

[0086] Upon acquiring the second set of properties, after the time interval, the terminal device 110 performs (370) communication with the network device 120 in the second frequency portion based on the second set of properties using the second RS as the QCL source RS.

[0087] FIG. 5 illustrates an example 500 of BWP switching or CC switching according to some embodiments of the present disclosure. Overall, in the example 500, the terminal device 110 may maintain the QCL assumption before the terminal device 110 can obtain a new stable result after several measurements of the QCL-Type A source RS in the new BWP / CC. A time interval may be introduced for the terminal device 110 to measure the RS identified by (the second BWP / CC ID+the first RS ID). During this time interval, the terminal device 110 is allowed to communicate with the network device 120 based on the QCL assumption for the RS (i.e., the first BWP ID+the first RS ID) in the last BWP before the BWP switching. The length of the time interval may be N (e.g., 3) times the periodicity of the corresponding RS.

[0088] Specifically, as shown, the terminal device 110 receives first RSs 511-1, 511-2, and 511-3 from the network device 120 in a first BWP / CC. The first RSs 511-1, 511-2, and 511-3 may be identified by (first BWP / CC ID+RS ID). It should be understood that the transmissions of RSs 511-1 to 511-3 may be multiple transmissions of a single RS, for example, periodic transmissions of the single RS. The terminal device 110 receives a PDCCH 512 that schedules a PDSCH 513 in a second BWP / CC. The dashed arrows in FIG. 5 do not represent actual transmissions.

[0089] The network device 120 transmits the second RSs 521-1, 521-2, and 521-3 in the second BWP / CC. It should be understood that the transmissions of RSs 521-1 through 521-3 may be multiple transmissions of a single RS, for example, periodic transmissions of the single RS. The second BWP / CC ID is not present for the RS in the QCL-Info of the TCI state.

[0090] At the start 531 of time interval 530, terminal device 110 completes the switching procedure to the second BWP / CC. After switching to the second BWP / CC, terminal device 110 uses the first RS identified by (first BWP / CC ID+RS ID) as the QCL RS until time interval 530 ends at 532.

[0091] Within this time interval 530, the terminal device 110 acquires a second set of properties by measuring second RSs 521-1 and 521-2 within a second BWP / CC.

[0092] After time interval 530, terminal device 110 uses second RS 521-3 identified by (second BWP / CC ID+RS ID) as the QCL reference RS. Additionally, after time interval 530, terminal device 110 receives PDSCH 514 in the second BWP / CC based on the second set of properties. Additionally, after this time interval, terminal device receives / transmits all channels / RSs for which the indicated TCI state applies, including at least one of terminal device dedicated PDCCH / PDSCH, terminal device dedicated PUCCH / PUSCH, in the second BWP / CC based on the second set of properties.

[0093] An embodiment of the present disclosure supports terminal device 110 assuming that the QCL-Type A source RS is in the last BWP / CC before the BWP / CC switch if there is no BWP / CC ID for the QCL-Type A source RS, until terminal device 110 can obtain new measurements in the new BWP / CC. Additionally, an embodiment of the present disclosure allows terminal device 110 enough time to measure the new RS identified by (second BWP / CC ID+RS ID).

[0094] In some embodiments, a BWP / CC switch deactivates the TCI state from which the BWP / CC was switched, In some embodiments, a BWP / CC switch activates the TCI state to which the BWP / CC was switched.

[0095] In some embodiments, after switching to the second BWP / CC, the terminal device assumes that the QCL source RS in the QCL-Info of the old TCI state is in the first BWP / CC until the terminal device receives a TCI state activation or indication based on the MAC CE or DCI. The old TCI state may be the TCI state that applies when the terminal device 110 learns of the switch by receiving, decoding, or acknowledging a BWP / CC switch command.

[0096] In some embodiments, after switching to the second BWP / CC, the terminal device assumes that the QCL source RS in the QCL-Info in the old TCI state is in the first BWP / CC before this time interval expires, and until the terminal device receives a TCI state activation or indication based on a MAC CE or DCI, the terminal device assumes that the QCL source RS in the QCL-Info in the old TCI state is in the second BWP / CC after this time interval expires. The old TCI state may be the TCI state that is applied when the terminal device 110 learns of the switch by receiving, decoding, or acknowledging a BWP / CC switch command.

[0097] In some embodiments, after switching to the second BWP / CC, the terminal device assumes that the QCL source RS in the QCL-Info of the indicated TCI state is in the first BWP / CC until the terminal device receives a TCI state activation or indication based on a MAC CE or DCI. The indicated TCI state may be the TCI state received immediately before, or immediately after, the BWP / CC switch command.

[0098] In some embodiments, after switching to the second BWP / CC, the terminal device assumes that the QCL source RS in the QCL-Info of the indicated TCI state is in the first BWP / CC before the time interval expires, and until the terminal device receives a TCI state activation or indication based on a MAC CE or DCI, the terminal device assumes that the QCL source RS in the QCL-Info of the indicated TCI state is in the second BWP / CC after the time interval expires. The indicated TCI state may be the TCI state received immediately before or immediately after along with the BWP / CC switch command.

[0099] In some embodiments, the terminal device 110 may switch back from the second frequency part to the first frequency part due to expiration of a timer. For example, in case of BWP switching, the timer may be the conventional RRC IE bwp-InactivityTimer (hereinafter also referred to as bwp-InactivityTimer), which is the time interval in ms during which the terminal device 110 switches back to the default bandwidth part (see TS 38.321, clause 5.15). For example, in case of CC switching, such as MAC CE based SCell activation, the timer may be the conventional RRC IE sCellDeactivationTimer.

[0100] In some embodiments, considering a timer-based BWP / CC switching, immediately after switching back from the second BWP to the first BWP, for example due to expiration of the configured bwp-InactivityTimer, the terminal device 110 may still have measurement results available from the RS in BWP#1 if the timer value is small, for example smaller than [1280ms]. In such an embodiment, in response to switching back to the first frequency part, the terminal device 110 may determine the time period of the timer from the last transmission on the first frequency part. For example, the time period of the timer is related to the configured value of the bwp-InactivityTimer.

[0101] In some embodiments, the last transmission may be a transmission of the RS, which may be identified by (first BWP / CC ID+RS ID). Alternatively, this last transmission may be any transmission, including a data transmission.

[0102] If the time period is less than the first threshold, the terminal device 110 may use the first RS as a QCL source RS to perform communication with the network device 120 in the first frequency portion. The first threshold may be predefined, may be set by the network device 120, or may be reported as a capability by the terminal device 110. This will be described with reference to FIG. 6A.

[0103] FIG. 6A illustrates an example 600 of a BWP or CC switching according to some embodiments of the present disclosure.

[0104] As shown, terminal device 110 receives first RSs 611-1 and 611-2 from network device 120 in a first BWP / CC. The first RSs 611-1 and 611-2 may be identified by (first BWP / CC ID+RS ID). Terminal device 110 receives PDSCH 613 in a second BWP / CC using first RSs 611-1 and 611-2 as QCL source RSs. The dashed arrows in FIG. 6A do not represent actual transmissions or measurements.

[0105] The network device 120 transmits the second RSs 621-1 and 621-2 in a second BWP / CC.

[0106] After switching to the second BWP / CC and acquiring a second set of properties by measuring second RSs 621-1 and 621-2 in the second BWP / CC, the terminal device 110 receives a PDSCH 614 in the second BWP / CC based on the second set of properties.

[0107] The terminal device 110 switches back from the second BWP / CC to the first BWP / CC because the bwp-InactivityTimer expires at 630. Because the time period of the bwp-InactivityTimer since the last transmission in the first BWP / CC is less than the first threshold, the terminal device 110 receives the PDSCH 612 in the first BWP / CC using the first RSs 611-1 and 611-2 as QCL source RSs.

[0108] The solution of embodiment 600 allows stable transmission to be achieved faster if terminal device 110 can reuse previous QCL assumptions.

[0109] On the other hand, if the time period is equal to or greater than the first threshold, the terminal device 110 may use the second RS as the QCL source RS to communicate with the network device 120 in the first frequency portion. The terminal device 110 may obtain a third set of properties by measuring the first RS, and use the first RS as the QCL RS to communicate with the network device 120 in the first frequency portion based on the third set of properties. In other words, for timer-based BWP / CC switching, some embodiments of the present disclosure support the terminal device 110 to assume that the QCL-Type A source RS is in the last BWP / CC before the BWP / CC switching only if the value of the timer is greater than a threshold when there is no BWP / CC ID for the QCL-Type A source RS. This will be described with reference to FIG. 6B.

[0110] FIG. 6B illustrates an example 605 of a BWP or CC switch according to some embodiments of the present disclosure.

[0111] Example 605 differs significantly from example 600 in that the time period of the bwp-InactivityTimer since the last transmission in the first BWP / CC is greater than the first threshold.

[0112] The terminal device 110 switches back from the second BWP / CC to the first BWP / CC because the bwp-InactivityTimer expires at 631. After the switch, the terminal device 110 receives the PDSCH 641 using the second RSs 621-1, 621-2, and 621-3 as QCL source RSs.

[0113] Additionally, since the time period of bwp-InactivityTimer since the last transmission in the first BWP / CC is greater than or equal to the first threshold, after switching, the terminal device 110 acquires a third set of properties by measuring the first RSs 611-3 and 611-4 in the first BWP / CC, and receives the PDSCH 642 in the first BWP / CC using the first RSs 611-3 and 611-4 as QCL RSs.

[0114] In some embodiments, the terminal device 110 may further switch from the second frequency portion to the third frequency portion before the second set of properties is acquired. In such embodiments, in response to the further switch, the terminal device 110 may determine the length of time that the scheduling frequency portion is active. If the length of time is equal to or greater than a second threshold, the terminal device 110 may determine the reference frequency portion to be the scheduling frequency portion. If the length of time is less than the second threshold, the terminal device 110 may determine the reference frequency portion to be the active frequency portion before the last frequency portion switch. This will be described with reference to FIG. 7.

[0115] FIG. 7 is a diagram illustrating an example BWP or CC switching 700 according to some embodiments of the present disclosure.

[0116] As shown, terminal device 110 receives first RSs 711-1, 711-2, and 711-3 from network device 120 in a first BWP / CC. First RSs 711-1, 711-2, and 711-3 may be identified by (first BWP / CC ID+RS ID). Terminal device 110 receives PDCCH 712, which schedules PDSCH 713, in a second BWP / CC.

[0117] The terminal device 110 receives a PDSCH 713 in a second BWP / CC using the first RSs 711-2 and 711-3 as QCL source RSs. The dashed arrows in Figure 7 do not represent actual transmissions or measurements. The network device 120 transmits a second RS 721-1 in the second BWP / CC.

[0118] Before acquiring the second set of properties by measuring the second RS 721-1 in the second BWP / CC, terminal device 110 switches from the second BWP / CC to a third BWP / CC. Terminal device 110 receives a PDCCH 714 that schedules a PDSCH 715 in the third BWP / CC.

[0119] Because the length of time that the scheduling BWP / CC (i.e., the second BWP / CC) is active is less than the second threshold, the terminal device 110 determines the reference BWP / CC to be the first BWP / CC before the last BWP / CC switch. Thus, the terminal device 110 receives a PDSCH 715 in the third BWP / CC based on the first set of properties using the first RSs 711-2 and 711-3 as QCL source RSs. In the third BWP / CC, the terminal device 110 obtains a fourth set of properties by measuring the third RSs 731-1 and 731-2. Then, the terminal device 110 receives a PDSCH 716 based on the fourth set of properties using the third RSs 731-1 and 731-2 as QCL RSs.

[0120] The solution of embodiment 700 avoids the problem of fast BWP / CC switching.

[0121] As mentioned above, the TCI-State IE may indicate qcl-Type1 and qcl-Type2. For example, qcl-Type1 may be QCL type A, B, or C for DL, and qcl-Type2 may be QCL type D for UL Tx spatial filter for DL ​​or UL.

[0122] In some embodiments, the terminal device 110 may obtain a first set of properties by measuring a first RS and a third RS, and obtain a second set of properties by measuring a second RS and a fourth RS. The third RS and the fourth RS both have a second ID (also referred to as a second RS ID). In some embodiments, the first RS and the second RS may be QCL type A / B / C RSs, and the third RS and the fourth RS may be QCL type D RSs. In such embodiments, if there is no BWP / CC ID in the QCL-Info of both TCI states for the QCL type A / B / C RSs and for the QCL type D RSs, the terminal device 110 may treat the QCL type A / B / C and QCL type D assumptions differently.

[0123] In some embodiments, the QCL type A / B / C RSs (i.e., the first RS and the second RS) may be identified by a first RS ID, and the QCL type D RSs (i.e., the third RS and the fourth RS) may be identified by a second RS ID, and the following scenarios need to be handled by assuming that no BWP / CC ID is present in the QCL-Info of both TCI states for the QCL type A / B / C RSs and for the QCL type D RSs:

[0124] Scenario 1: The first RS ID and the second RS ID are different, and a QCL type D relationship is always assumed between an RS identified by the first BWP / CC ID + second RS ID and an RS identified by the second BWP / CC ID + second RS ID, e.g., a third RS and a fourth RS.

[0125] Scenario 2: The first RS ID and the second RS ID are different, and no QCL type-D relationship is always assumed between the third RS and the fourth RS.

[0126] Scenario 3: The first RS ID and the second RS ID are the same, and a QCL type D relationship is always assumed between the third RS and the fourth RS.

[0127] Scenario 4: The first RS ID and the second RS ID are the same, and no QCL type-D relationship is assumed at any time between the third RS and the fourth RS.

[0128] In some embodiments, the different time intervals depend on whether the QCL type D RS and the QCL type A / B / C RS are the same or whether a QCL type D relationship is assumed between the third RS and the fourth RS.

[0129] In some embodiments, if a QCL type-D relationship is assumed between the third RS and the fourth RS, it means that both RSs may be received via the same receive (Rx) beam. In such embodiments, there is no need to correct the Rx beam after BWP / CC switching.

[0130] In another embodiment, if no QCL type-D relationship is assumed between the third RS and the fourth RS, it means that both RSs may or may not be received via the same Rx beam. In such an embodiment, the terminal device 110 may select a correction time interval (T BeamRefinement Next, the terminal device 110 may determine the correction time interval and the QCL time interval T QCL Based on this, the QCL time interval T QCL For example, the terminal device 110 may update T QCL max(T QCL ,T BeamRefinement ) or (T QCL +T BeamRefinement ) may be extended.

[0131] In an embodiment where the QCL type D relationship is not assumed, if the first RS ID and the second RS ID are different, it means that the terminal device 110 can obtain the QCL type A parameters using another TCI set for the QCL type D RS. Therefore, the terminal device 110 may need to correct the Rx beam after the BWP / CC switching. In addition, the terminal device 110 may QCL and T BeamRefinement The longer of the two is T QCL In other words, the terminal device 110 may update max(T QCL ,T BeamRefinement ) in T QCL may be updated.

[0132] In an embodiment where the QCL type D relationship is not assumed, if the first RS ID and the second RS ID are the same, it means that the terminal device 110 needs to obtain QCL type A and D parameters from the same RS. The terminal device 110 needs to first find the Rx beam (QCL type D parameters), and then apply this Rx beam to further obtain QCL type A parameters. In addition, the terminal device 110 needs to QCL and T BeamRefinement With T QCL may be updated.

[0133] In some embodiments, for the UL, a QCL-Type D source RS should be interpreted as meaning that the target RS may transmit via the same transmit (Tx) beam as the source RS, or the target RS may transmit via a Tx beam corresponding to the Rx beam for the source RS.

[0134] In some embodiments, during this time interval, the terminal device 110 may receive only the second RS without further communication with the network device 120. The QCL reference RS may always be identified by the second BWP / CC ID+RS ID, as agreed in Rel-17, as will be described with reference to FIG.

[0135] FIG. 8 is a diagram illustrating an example 800 of a BWP or CC switch according to some embodiments of the present disclosure.

[0136] As shown, embodiment 800 is similar to embodiment 500. Embodiment 800 differs from embodiment 500 in that in embodiment 800, terminal device 110 receives only second RSs 421-1 and 421-2 in the second frequency portion without receiving PDSCH 413 from network device 120 with the indicated TCI state applied.

[0137] In an embodiment in which the terminal device 110 receives only the second RS within this time interval without performing communication with the network device 120 based on the indicated TCI state, the terminal device 110 may determine this time interval by performing the following:

[0138] The terminal device 110 may receive the DCI from the network device 120. The DCI includes a bandwidth part indicator (BWP ID) field and a Transmission Configuration Indicator (TCI) field.

[0139] If the bandwidth part indicator field indicates a new BWP, the terminal device 110 determines the slot when the DCI was acknowledged, the number of symbols after the last symbol of the acknowledgement, and the configured time interval for switching (T switch ) and the QCL time interval (T QCL ) the timing of applying the TCI may be determined based on the above.

[0140] On the other hand, if the bandwidth part indicator field indicates the current BWP, the terminal device 110 may determine the TCI application timing based on the slot when the DCI was acknowledged and the number of symbols after the last symbol of the acknowledgement.

[0141] In some embodiments, if the bandwidth part indicator field indicates a new BWP and the TCI field indicates a new TCI state that is different from the current TCI state, the terminal device 110 determines the slot when the DCI was acknowledged, the number of symbols after the last symbol of the acknowledgement, and the configured time interval for switching (T switch ) and the QCL time interval (T QCL ) to determine the TCI application timing. If the bandwidth part indicator field indicates a new BWP and the TCI field indicates the same TCI state as the current TCI state, the terminal device 110 determines the slot when the DCI was acknowledged, the number of symbols after the last symbol of the acknowledgement, and the set time interval for switching (T switch ) the timing of applying the TCI may be determined based on the above.

[0142] When the TCI application timing is determined, the terminal device 110 may determine a time interval based on the TCI application timing. For example, the terminal device 110 may determine the TCI application timing as the end of a time interval.

[0143] Alternatively, in an embodiment in which within this time interval the terminal device 110 receives only the second RS without performing communication with the network device 120 based on the indicated TCI state, this time interval may be related to the value of the bwp-InactivityTimer and may be related to the length of time the scheduling BWP / CC is active.

[0144] After the determined TCI application timing, the terminal device receives a PDSCH based on the indicated TCI state, and if there is no BWP / CC ID for the QCL source RS in the QCL-Info of the TCI state, the terminal device assumes that the QCL source RS is within the BWP / CC to which the TCI state applies. Additionally, after the determined TCI application timing, the terminal device receives / transmits all channels / RSs to which the indicated TCI state applies, including at least one of the terminal device dedicated PDCCH / PDSCH and the terminal device dedicated PUCCH / PUSCH, according to the QCL assumption that the QCL source RS is within the BWP / CC to which the TCI state applies.

[0145] 9 is a flowchart of an example method 900 according to some embodiments of the present disclosure. In some embodiments, the method 900 may be implemented in a terminal device. For example, the method 900 may be implemented in a terminal device 110 as shown in FIG.

[0146] In response to switching to the second frequency portion, the terminal device determines a time interval during which the terminal device uses a first RS received from the network device on the first frequency portion as a QCL RS, at block 910. The terminal device performs communication with the network device before the time interval expires based on at least a first set of properties obtained by measuring the first RS.

[0147] In block 920, the terminal device obtains a second set of properties within the time interval by measuring at least a second RS received from the network device in a second frequency portion, the second RS and the first RS having a first identity.

[0148] In block 930, after the time interval, the terminal device performs communication with the network device on the second frequency portion using the second RS as a QCL RS based on the second set of properties.

[0149] In some embodiments, determining a time interval includes determining a start slot when the terminal device becomes aware of the switch and a configured time interval for the switch based on configuration information received from the network device, determining a QCL time interval for acquiring the second set of properties, and determining the time interval based on at least one of the start slot, the configured time interval for the switch, and the QCL time interval.

[0150] In some embodiments, determining the QCL time interval includes obtaining at least one parameter from the configuration information, among a periodicity of the second reference signal, a set number of transmission occasions of the second reference signal, a QCL type of the second reference signal, numerology information of the second reference signal, or a predefined capability-related value of the terminal device, and determining the QCL time interval based on the at least one parameter.

[0151] In some embodiments, the configured number is determined from at least one of configuration information, terminal device capabilities, or standard requirements.

[0152] In some embodiments, obtaining the second set of properties includes determining a QCL type of the second reference signal based on configuration information received from the network device, and determining the second set of properties based on the QCL type by measuring the second reference signal at the second frequency portion.

[0153] In some embodiments, the switch from the first frequency portion to the second frequency portion is a bandwidth part (BWP) switch or a component carrier (CC) switch.

[0154] In some embodiments, the first frequency portion is one of: an active BWP before a BWP switch, an active CC before a CC switch, a BWP or CC to which scheduling information is transmitted, a BWP or CC in which a TCI-State is set, a BWP or CC in which one or more TCI state pools are set, a reference BWP or reference CC, a default BWP or default CC, an initial downlink or uplink BWP, or an initial downlink or uplink CC.

[0155] In some embodiments, the method 900 further includes, in response to switching back from the second frequency portion to the first frequency portion due to expiration of a timer, determining a time period of the timer since a last transmission on the first frequency portion, and, in accordance with a determination that the time period is less than a first threshold, performing communication with the network device on the first frequency portion using the first reference signal as the QCL reference signal.

[0156] In some embodiments, method 900 further includes, in accordance with a determination that the time period is greater than or equal to the first threshold, performing communication with the network device on the first frequency portion using the second reference signal as the QCL reference signal, obtaining a third set of properties by measuring the first reference signal, and performing communication with the network device on the first frequency portion using the first reference signal as the QCL reference signal based on the third set of properties.

[0157] In some embodiments, the time period is related to the value of the bwp-Inactivity Timer.

[0158] In some embodiments, the method 900 further includes determining a length of time that a scheduling frequency portion is active in response to switching from the second frequency portion to a third frequency portion before the second set of properties is acquired, determining a reference frequency portion to be a scheduling frequency portion in accordance with a determination that the length of time is greater than or equal to a second threshold, and determining the reference frequency portion to be an active frequency portion before the last frequency portion switch in accordance with a determination that the length of time is less than the second threshold.

[0159] In some embodiments, the first set of properties is obtained by measuring the first reference signal and the third reference signal, and the second set of properties is obtained by measuring the second reference signal and the fourth reference signal, both of which have a second identity. In such embodiments, determining the QCL time interval includes determining a correction time interval for correcting a receive beam after the switching if a QCL type-D relationship is not assumed between the third reference signal and the fourth reference signal, and updating the QCL time interval based on the correction time interval and the QCL time interval.

[0160] In some embodiments, updating the QCL time interval includes updating the QCL time interval by the longer of the correction time interval and the QCL time interval when the first identification information of the first reference signal and the second reference signal is different from the second identification information of the third reference signal and the fourth reference signal.

[0161] In some embodiments, updating the QCL time interval includes updating the QCL time interval by the sum of the QCL time interval and the correction time interval when the first identification information of the first reference signal and the second reference signal is the same as the second identification information of the third reference signal and the fourth reference signal.

[0162] In some embodiments, within the time interval, the terminal device receives only the second reference signal without performing further communication with the network device. In such embodiments, determining the time interval includes receiving downlink control information from the network device, the downlink control information including a bandwidth part indicator field and a Transmission Configuration Indicator (TCI) field, determining a TCI application timing based on a slot when the downlink control information was acknowledged and a number of symbols after a last symbol of the acknowledgment, a configuration time interval for the switch, and a QCL time interval according to a determination that the bandwidth part indicator field indicates a new bandwidth part, determining the TCI application timing based on the slot when the downlink control information was acknowledged and the number of symbols after a last symbol of the acknowledgment, according to a determination that the bandwidth part indicator field indicates a current bandwidth part, and determining the time interval based on the TCI application timing.

[0163] In some embodiments, the method 900 further includes receiving configuration information from the network device, the configuration information including at least one of a starting slot when the terminal device becomes aware of the switch, a configured time interval for the switch, a periodicity of the second reference signal, a configured number of transmission occasions for the second reference signal, a QCL type of the second reference signal, numerology information of the second reference signal, or a predefined capability-related value of the terminal device.

[0164] In some embodiments, the method 900 further includes obtaining a TCI state indication from downlink control information or a MAC CE activation command from the network device. In some embodiments, a TCI state identification (ID) in the TCI state indication refers to a TCI state in a TCI state pool.

[0165] 10 is a flowchart of an example method 1000 according to some embodiments of the present disclosure. In some embodiments, the method 1000 may be implemented in a network device. For example, the method 1000 may be implemented in a network device 120 as shown in FIG.

[0166] In response to switching to the second frequency portion, the network device determines a time interval during which the terminal device uses a first RS transmitted by the network device on the first frequency portion as a QCL RS, at block 1010. The terminal device performs communication with the network device before the time interval expires based on at least a first set of properties obtained by measuring the first RS.

[0167] In block 1020, the network device transmits a second RS to the terminal device on the second frequency portion after the start of the time interval, the second RS and the first RS having a first identification.

[0168] In block 1030, the network device performs communication with the terminal device on the second frequency portion using the second RS as the QCL RS after the time interval.

[0169] In some embodiments, the method 1000 further includes transmitting configuration information to the terminal device, the configuration information including at least one of a starting slot when the terminal device learns of the switch, a configured time interval for the switch, a periodicity of the second reference signal, a configured number of transmission occasions of the second reference signal, a QCL type of the second reference signal, numerology information of the second reference signal, or a predefined capability-related value of the terminal device.

[0170] In some embodiments, the method 1000 further includes transmitting to the terminal device downlink control information or a MAC CE activation command including a TCI state indication, in such an embodiment, a TCI state identification (ID) in the TCI state indication refers to a TCI state in a TCI state pool.

[0171] In some embodiments, the method 1000 further includes transmitting the second reference signal to the terminal device within the time interval without performing further communication with the terminal device.

[0172] 11 is a schematic block diagram of an apparatus 1100 suitable for implementing some embodiments of the present disclosure. The apparatus 1100 may be considered as another exemplary embodiment of the terminal apparatus 110 or the network apparatus 120 shown in FIG. 1. Thus, the apparatus 1100 may be implemented in the terminal apparatus 110 or the network apparatus 120, or as at least a part thereof.

[0173] As shown, the apparatus 1100 comprises a processor 1110, a memory 1120 coupled to the processor 1110, a suitable transmitter (TX) and receiver (RX) 1140 coupled to the processor 1110, and a communication interface coupled to the TX / RX 1140. The memory 1120 stores at least a portion of a program 1130. The TX / RX 1140 is used for bidirectional communication. The TX / RX 1140 has at least one antenna to facilitate communication, although the access nodes referred to herein may in practice have multiple antennas. The communication interface may represent any interface required for communication with other network elements, such as an X2 interface for bidirectional communication between gNBs or 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 a gNB or eNB and a relay node (RN), or a Uu interface for communication between a gNB or eNB and a terminal device.

[0174] The program 1130 is assumed to include program instructions that, when executed by the associated processor 1110, enable the device 1100 to operate according to embodiments of the present disclosure, as described herein with reference to Figures 1 and 3-10. The embodiments of the present disclosure may be realized by computer software executable by the processor 1110 of the device 1100, or by hardware, or by a combination of software and hardware. The processor 1110 may be configured to implement various embodiments of the present disclosure. Furthermore, the combination of the processor 1110 and the memory 1120 may form a processing means 1150 suitable for implementing various embodiments of the present disclosure.

[0175] The memory 1120 may be of any type suitable for a local technology network and may be implemented using any suitable data storage technology, such as, by way of non-limiting example, non-transitory computer-readable storage media, semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. Although only one memory 1120 is shown in the device 1100, there may be several physically different memory modules in the device 1100. The processor 1110 may be of any type suitable for a local technology network and may include, by way of non-limiting example, one or more of a general purpose computer, a special purpose computer, a microprocessor, a digital signal processor (DSP) and a processor based on a multi-core processor architecture. The device 1100 may have multiple processors, for example application specific integrated circuit chips time-slaved to a clock that synchronizes the main processor.

[0176] Components included in the devices and / or apparatus of the present disclosure may be implemented in various ways, including software, hardware, firmware, or any combination thereof. In one embodiment, one or more units may be implemented using software and / or firmware, such as machine-executable instructions stored on a storage medium. In addition to or in lieu of machine-executable instructions, some or all of the units in the devices and / or apparatus may be implemented, at least in part, by one or more hardware logic components. By way of example and not limitation, exemplary types of hardware logic components that may be used include Field-programmable Gate Arrays (FPGAs), Application-specific Integrated Circuits (ASICs), Application-specific Standard Products (ASSPs), System-on-a-chip systems (SOCs), Complex Programmable Logic Devices (CPLDs), and the like.

[0177] Overall, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic, or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor, or other computing device. Although various aspects of the embodiments of the present disclosure have been illustrated and described using block diagrams, flow charts, or some other pictorial representations, it should be understood that the blocks, devices, systems, techniques, or methods described herein may be implemented, by way of non-limiting examples, in hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing device, or any combination thereof.

[0178] The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as instructions included in a program module, that execute in a device on a target real or virtual processor to perform a process or method described above with reference to any one of Figures 3 to 10. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data types. In various embodiments, the functionality of the program modules may be combined or split between program modules as appropriate. The machine-executable instructions of the program modules may be executed in local or distributed devices. In a distributed device, the program modules may be located in both local and remote storage media.

[0179] Program codes for carrying out the methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, a special purpose computer, or other programmable data processing device, and when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may run entirely on the machine, partially on the machine, as a separate software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0180] The above program code may be implemented on a machine-readable medium, which may be any tangible medium that can contain or store a program used by or associated with an instruction execution system, 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, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or apparatus, or any suitable combination of the aforementioned media. More specific examples of the machine-readable storage medium may include an electrical connection having one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the aforementioned.

[0181] It should be understood that although operations have been described in a particular order, it is not required that such operations be performed in the particular order shown, or in any sequential order, or that all of the operations described be performed, in order to achieve desired results. In some cases, multitasking or parallel processing may be advantageous. Similarly, although details of several specific embodiments are included in the above discussion, these should not be construed as limitations on the scope of the disclosure, but rather as descriptions of features that may be unique to certain embodiments. Some features described in the context of individual embodiments may be realized 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.

[0182] Although the present disclosure has been described in language specific to structural features and / or methodological acts, it should be understood that the present disclosure, as defined in the appended claims, is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

1. A user equipment (UE), Means for supporting a BWP switch configured to switch an active BWP from a first bandwidth part (BWP) to which a first transmission configuration indicator (TCI) state applies to a second BWP to which a second TCI state applies, the first TCI state being associated with a first downlink (DL) reference signal and the second TCI state being associated with a second DL reference signal; means for configuring the UE to perform the communication in the first TCI state before a delay in the second BWP when the UE has information about the second TCI state for performing the communication in the second BWP; means for assuming that the second DL reference signal is configured in the second BWP to which the second TCI state applies if the second DL reference signal is a quasi-co-location type A or D source reference signal (QCL (quasi co-location) type A / D source RS) and a bwp-id for the second DL reference signal in the QCL-info of the second TCI state is not configured; A UE including:

2. The UE is configured to perform the communication in the second TCI state after the delay within the second BWP if the UE has the information regarding the second TCI state for performing the communication in the second BWP. The UE of claim 1.

3. The UE is configured to apply the first TCI state from a reference BWP.

3. The UE according to claim 1 or 2.

4. means for assuming that the first DL reference signal is set in the first BWP to which the first TCI state applies if the first DL reference signal is a QCL-type A / D source RS and a bwp-id for the first DL reference signal in the QCL-info of the first TCI state is not set; The UE of claim 1 or 2, further comprising:

5. A means for receiving the first DL reference signal on the first BWP; means for receiving the second DL reference signal on the second BWP; The UE of claim 4 further comprising:

6. The communication includes receiving a physical downlink control channel (PDCCH), 3. The UE according to claim 1 or 2.

7. The communication includes receiving a physical downlink shared channel (PDSCH), 3. The UE according to claim 1 or 2.

8. A method for a user equipment (UE), comprising: Supporting a BWP switch configured to switch an active BWP from a first bandwidth part (BWP) to which a first transmission configuration indicator (TCI) state applies to a second BWP to which a second TCI state applies, the first TCI state being associated with a first downlink (DL) reference signal and the second TCI state being associated with a second DL reference signal; The UE is configured to perform the communication in the first TCI state before a delay in the second BWP when the UE has information about the second TCI state for performing the communication in the second BWP; If the second DL reference signal is a quasi-co-location type A or D source reference signal (QCL (quasi co-location) type A / D source RS) and a bwp-id for the second DL reference signal in the QCL-info of the second TCI state is not set, it is assumed that the second DL reference signal is set in the second BWP to which the second TCI state applies; The method includes:

9. The UE is configured to perform the communication in the second TCI state after the delay within the second BWP if the UE has the information regarding the second TCI state for performing the communication in the second BWP. The method according to claim 8.

10. The UE is configured to apply the first TCI state from a reference BWP.

10. The method according to claim 8 or 9.

11. If the first DL reference signal is a QCL-type A / D source RS and a bwp-id for the first DL reference signal in the QCL-info of the first TCI state is not set, it is assumed that the first DL reference signal is set in the first BWP to which the first TCI state applies; The method of claim 8 or 9, further comprising:

12. Receiving the first DL reference signal on the first BWP; and receiving the second DL reference signal on the second BWP; The method of claim 11 further comprising:

13. The communication includes receiving a physical downlink control channel (PDCCH), 10. The method according to claim 8 or 9.

14. The communication includes receiving a physical downlink shared channel (PDSCH), 10. The method according to claim 8 or 9.

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