Method and apparatus for enabling a multiple transmission-reception point operation in a wireless communication system
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- GOOGLE LLC
- Filing Date
- 2023-09-29
- Publication Date
- 2026-07-08
AI Technical Summary
Enabling multiple transmission-reception point (M-TRP) operation under the unified transmission configuration indicator (TCI) states framework is challenging due to increased complexity in determining which channels or reference signals can apply unified TCI states, especially when UE-initiated beam selection is enabled.
The proposed solution involves determining the applicability of unified TCI states for receiving physical downlink shared channel (PDSCH) transmissions and configuring signals to indicate whether channels or reference signals apply UE-suggested beams, thereby reducing latency and avoiding beam failures.
This approach enables efficient M-TRP operation by reducing latency in beam selection/switching, ensuring consistent application of unified TCI states, and minimizing the risk of radio link failures.
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Figure CN2023123036_03042025_PF_FP_ABST
Abstract
Description
METHOD AND APPARATUS FOR ENABLING A MULTIPLE TRANSMISSION-RECEPTION POINT OPERATION IN A WIRELESS COMMUNICATION SYSTEMTECHNICAL FIELD
[0001] The present disclosure relates generally to wireless communication, and more particularly, to a multiple transmission-reception point (M-TRP) operation in a wireless communication system.BACKGROUND
[0002] The Third Generation Partnership Project (3GPP) specifies a radio interface referred to as fifth generation (5G) new radio (NR) (5G NR) . An architecture for a 5G NR wireless communication system includes a 5G core (5GC) network, a 5G radio access network (5G-RAN) , a user equipment (5G UE) , etc. The 5G NR architecture seeks to provide increased data rates, decreased latency, and / or increased capacity compared to prior generation cellular communication systems.
[0003] Wireless communication systems, in general, provide various telecommunication services (e.g., telephony, video, data, messaging, broadcasts, etc. ) based on multiple-access technologies, such as orthogonal frequency division multiple access (OFDMA) technologies, that support communication with multiple UEs. Improvements in mobile broadband continue the progression of such wireless communication technologies. For example, extending the unified transmission configuration indicator (TCI) states framework to the M-TRP operation is important, however, it is difficult to enable the M-TRP operation under the unified TCI states framework.
[0004] BRIEF SUMMARY
[0005] The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects. This summary neither identifies key or critical elements of all aspects nor delineates the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.
[0006] Under the unified TCI states framework, a UE may be indicated one or more unified TCI states that can be applied for downlink (DL) and / or uplink (UL) channel (s) and reference signal (s) RS (s) . The unified TCI states framework reduces the signaling overhead and latency of beam indication.
[0007] A physical downlink shared channel (PDSCH) transmission may follow or apply the indicated unified TCI state (s) (e.g., a first, a second, or both indicated unified TCI states) . However, for some control resource sets (CORESETs) or physical downlink control channels (PDCCHs) , the network (NW) entity may configure these CORESETs or PDCCHs to not follow or apply the indicated unified TCI state (s) . For example, the NW) entity may configure CORESET#0 or CORESET (s) at least associated with commons search space (CSS) sets to not follow or apply the indicated unified TCI state (s) . Usually, the PDSCH transmission scheduled by the CORESET#0 or CORESET (s) associated with the CSS sets would carry a common signal, e.g., broadcast signal. Such PDSCH transmission (s) is / are also received by other UEs in the same physical serving cell. Thus, when the PDSCH transmission (s) is / are scheduled by these CORESETs, it may be of increased complexity to determine whether the scheduled PDSCH can follow the unified TCI states.
[0008] UE-initiated beam selection / switching may be supported in 5G NR, which allows the UE to report a recommended reference signal or unified TCI state. The recommended reference signal or unified TCI state may correspondingly become or derive the serving beam or serving TCI state for communication between the UE and the NW entity. In some examples, the NW entity may send further confirmation to confirm or approve the recommended reference signal or unified TCI state. In this way, the latency of the beam switching is reduced, and the potential beam failure may be avoided. However, the set of UL / DL channel (s) or RS (s) being able to apply the UE-suggested beams has been undefined and may not be the same as those applying the unified TCI states indicated by the NW entity. Therefore, it may be of increased complexity to determine which UL / DL channels or RSs can apply or follow the UE-suggested beam (s) or the TCI state (s) .
[0009] In a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM) or a lower-layer triggered mobility (LTM) procedure for reducing latency when performing cell switching, a field may be added in a PDCCH order for early timing advance (TA) acquisition, which may be referred to as a cell indicator field. This field may be used to indicate whether the triggered random access (RA) procedure is for the serving cell or the LTM candidate cell (s) . However, for an M-TRP 2 timing advance (2TA) scenario, another field may be introduced in the PDCCH order at least for inter-cell 2TA. The another field is for indicating which physical random access channel (PRACH) configuration is to be used, e.g., either PRACH configuration for the serving cell or PRACH configuration for the candidate cell (s) (e.g., neighboring cell (s) ) . It may be of increased complexity to interpret these two fields when they are present together in the PDCCH order.
[0010] Aspects of the present disclosure address the above-noted and other deficiencies by determining the applicability of unified TCI states in receiving a PDSCH transmission, for example, determining whether / how to use / apply the indicated joint / DL TCI states for the PDSCH transmission scheduled by a CORESET not following the indicated joint / DL TCI states. The PDSCH transmission may be used to transmit a cell-specific signal, e.g., broadcast signal. Whether the PDSCH transmission can use / apply / follow the indicated joint / DL TCI states when the PDSCH transmission is scheduled by a PDCCH in the CORESET is based on whether the CORESET uses / applies / follows the indicated joint / DL TCI states and / or a downlink control information (DCI) format. As an example, a TCI selection field in a DCI or TCI selection parameter provided by higher layers only works when the scheduling CORESET uses / applies / follows the indicated joint / DL TCI state (s) . If the scheduling CORESET does not use / apply / follow the indicated joint / DL TCI state (s) , the scheduled PDSCH transmission uses / applies / follows the same beam as the scheduling CORESET. As another example, the TCI selection field or TCI selection parameter still works even when the scheduling CORESET does not use / apply / follow the indicated joint / DL TCI state (s) . As still another example, the TCI selection parameter only works when the scheduling CORESET uses / applies / follows the indicated joint / DL TCI state (s) , but the TCI selection field still works even when the scheduling CORESET does not use / apply / follow the indicated joint / DL TCI state (s) .
[0011] According to some aspects, a UE receives, from a network entity, a first control signal indicating a first set of transmission configuration indicator (TCI) states. The UE receives from the network entity, a second control signal scheduling a physical downlink shared channel (PDSCH) transmission for a multiple transmission-reception point (M-TRP) scheme. The second control signal is associated with a second set of TCI states. The UE receives, from the network entity, the PDSCH transmission using at least one TCI state of the first set of TCI states or using the second set of TCI states based on a configuration of the second control signal.
[0012] According to some aspects, a NW entity transmits, to a UE, a first control signal indicating a first set of transmission configuration indicator (TCI) states. The NW entity transmits, to the UE, a second control signal scheduling a physical downlink shared channel (PDSCH) transmission for a multiple transmission-reception point (M-TRP) scheme. The second control signal is associated with a second set of TCI states. The NW entity transmits, to the UE (102) , the PDSCH transmission using at least one TCI state of the first set of TCI states or using the second set of TCI states based on a configuration of the second control signal.
[0013] Aspects of the present disclosure also address the above-noted and other deficiencies by determining which channels / RSs can follow or apply beams or TCI states suggested by a UE, when UE-indicated beam selection / switching is enabled. In one example, the NW entity configures a signal to indicate whether a channel or RS applies a UE-suggested beam. The signal may include a radio resource control (RRC) message, a MAC-CE or a DCI. Whether the channel or RS applies the UE-suggested beam may be configured per channel, per RS, per channel group, or per RS set. In another example, the UE suggests / indicates which channel / RS may apply the UE-suggested beam when reporting the UE-suggested beam. The channels or RSs using / following / applying the UE-suggested beam may not be able to use / follow / apply the NW-indicated beam, or vice-versa.
[0014] According to some aspects, a UE receives, from a network entity, a first control signal configuring UE-initiated beam selection for a multiple transmission-reception point (M-TRP) scheme. The UE transmits, to the network entity, a report indicating one or more UE-selected beams based on the first control channel. The UE communicates with the network entity using the one or more UE-selected beams for at least one of a channel or a reference signal for the M-TRP scheme.
[0015] According to some aspects, a NW entity transmits, to a UE, a first control signal configuring UE-initiated beam selection for a multiple transmission-reception point (M-TRP) scheme. The NW entity receives, from the UE, a report indicating one or more UE-selected beams based on the first control channel. The NW entity communicates with the UE using the one or more UE-selected beams for at least one of a channel or a reference signal for the M-TRP scheme.
[0016] Aspects of the present disclosure further address the above-noted and other deficiencies by determining how to interpret fields in a PDCCH order for triggering a contention-free random access (CFRA) procedure when the UE is configured with an inter-cell 2TA and an LTM simultaneously. For the inter-cell M-TRP 2TA, a first field (e.g., a second DCI field or a PRACH configuration field) is introduced in the PDCCH order to indicate which PRACH configuration to use for triggered the CFRA procedure. The first field may indicate a PRACH configuration for a serving cell or a PRACH configuration for a neighboring cell (e.g., PRACH configuration associated with an additional physical cell identifier (PCI) ) . For the LTM procedure, a second field (e.g., a third DCI field or a cell indicator field) is introduced in the PDCCH order to indicate a candidate cell for which the triggered CFRA is intended. The second field may indicate a serving cell or one of the configured candidate cells. In one example, the first field (e.g., the PRACH configuration field) applies when the second field (e.g., the cell indicator field) indicates a serving cell. In another example, the second field (e.g., cell indicator field) applies when the first field (e.g., PRACH configuration field) indicates a serving cell PRACH configuration. In still another example, a third field (e.g., a fourth DCI field) in the PDCCH order is introduced to indicate whether to apply the first field and / or the second field.
[0017] According to some aspects, a UE receives, from a network entity, a control signal including a first field or a second field different from the first field in a physical downlink control channel (PDCCH) order. The first field indicates that the PDCCH order is for triggering contention-free random access (CFRA) for a serving cell or a neighboring cell. The second field indicates that the PDCCH order is for triggering a lower-layer triggered mobility (LTM) procedure for the serving cell or a candidate cell. The UE communicates with the network entity based on at least one of the first field or the second field of the control signal.
[0018] According to some aspects, a NW entity transmits, to a UE, a control signal including a first field or a second field different from the first field in a physical downlink control channel (PDCCH) order. The first field indicates that the PDCCH order is for triggering contention-free random access (CFRA) for a serving cell or a neighboring cell. The second field indicates that the PDCCH order is for triggering a lower-layer triggered mobility (LTM) procedure for the serving cell or a candidate cell. The NW entity communicates with the UE based on at least one of the first field or the second field of the control signal.
[0019] By using the above techniques, the M-TRP operation is enabled under the unified TCI framework. The latency in the beam selection / switching may be reduced. The UE and the NW entity may have a common understanding on which channels / RS to apply the unified TCI states. Thus, the risk of a beam failure or a radio link failure (RLF) may be reduced or avoided. The performance of the wireless system may be improved.BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 illustrates a diagram of a wireless communications system that includes a plurality of user equipments (UEs) and network entities in communication over one or more cells according to an embodiment.
[0021] FIG. 2A illustrates a diagram of an example system with a distributed base station and / or a UE according to an embodiment.
[0022] FIG. 2B illustrates a diagram of an example base station including a central unit (CU) and a distributed unit (DU) of a distributed base station in the system of FIG. 1B according to an embodiment.
[0023] FIG. 3A illustrates a diagram of an example protocol stack according to an embodiment.
[0024] FIG. 3B illustrates a diagram of another example protocol stack according to an embodiment.
[0025] FIG. 4 is a signaling diagram illustrating communications between a UE and a network entity for a PDSCH transmission according to an embodiment.
[0026] FIG. 5A is a diagram illustrating an example of a PDSCH transmission according to an embodiment.
[0027] FIG. 5B is a diagram illustrating another example of a PDSCH transmission according to an embodiment.
[0028] FIG. 5C is a diagram illustrating yet another example of a PDSCH transmission according to an embodiment.
[0029] FIG. 6 is a signaling diagram illustrating communications between a UE and a network entity for a UE-initiated beam selection according to an embodiment.
[0030] FIG. 7 is a signaling diagram illustrating communications between a UE and a network entity for interpreting a PDCCH order according to an embodiment.
[0031] FIG. 8 is a flowchart of a method of wireless communication at a UE for a PDSCH transmission according to an embodiment.
[0032] FIG. 9 is a flowchart of a method of wireless communication at a network entity for a PDSCH transmission according to an embodiment.
[0033] FIG. 10 is a flowchart of a method of wireless communication at a UE for a UE-initiated beam selection according to an embodiment.
[0034] FIG. 11 is a flowchart of a method of wireless communication at a network entity for a UE-initiated beam selection according to an embodiment.
[0035] FIG. 12 is a flowchart of a method of wireless communication at a UE for interpreting a PDCCH order according to an embodiment.
[0036] FIG. 13 is a flowchart of a method of wireless communication at a network entity for indicating a PDCCH order according to an embodiment.
[0037] FIG. 14 is a diagram illustrating a hardware implementation for an example UE apparatus according to some embodiments.
[0038] FIG. 15 is a diagram illustrating a hardware implementation for one or more example network entities according to some embodiments.DETAILED DESCRIPTION
[0039] FIG. 1 illustrates a diagram 100 of a wireless communications system associated with a plurality of cells 190. The wireless communications system includes user equipments (UEs) 102 and base stations / network entities 104. Some base stations may include an aggregated base station architecture and other base stations may include a disaggregated base station architecture. The aggregated base station architecture utilizes a radio protocol stack that is physically or logically integrated within a single radio access network (RAN) node. A disaggregated base station architecture utilizes a protocol stack that is physically or logically distributed among two or more units (e.g., radio unit (RU) 106, distributed unit (DU) 108, central unit (CU) 110) . For example, a CU 110 is implemented within a RAN node, and one or more DUs 108 may be co-located with the CU 110, or alternatively, may be geographically or virtually distributed throughout one or multiple other RAN nodes. The DUs 108 may be implemented to communicate with one or more RUs 106. Any of the RU 106, the DU 108 and the CU 110 can be implemented as virtual units, such as a virtual radio unit (VRU) , a virtual distributed unit (VDU) , or a virtual central unit (VCU) . The base station / network entity 104 (e.g., an aggregated base station or disaggregated units of the base station, such as the RU 106 or the DU 108) , may be referred to as a transmission reception point (TRP) .
[0040] Operations of the base station 104 and / or network designs may be based on aggregation characteristics of base station functionality. For example, disaggregated base station architectures are utilized in an integrated access backhaul (IAB) network, an open-radio access network (O-RAN) network, or a virtualized radio access network (vRAN) , which may also be referred to a cloud radio access network (C-RAN) . Disaggregation may include distributing functionality across the two or more units at various physical locations, as well as distributing functionality for at least one unit virtually, which can enable flexibility in network designs. The various units of the disaggregated base station architecture, or the disaggregated RAN architecture, can be configured for wired or wireless communication with at least one other unit. For example, the base stations 104d, 104e and / or the RUs 106a, 106b, 106c, 106d may communicate with the UEs 102a, 102b, 102c, 102d, and / or 102s via one or more radio frequency (RF) access links based on a Uu interface. In examples, multiple RUs 106 and / or base stations 104 may simultaneously serve the UEs 102, such as by intra-cell and / or inter-cell access links between the UEs 102 and the RUs 106 / base stations 104.
[0041] The RU 106, the DU 108, and the CU 110 may include (or may be coupled to) one or more interfaces configured to transmit or receive information / signals via a wired or wireless transmission medium. For example, a wired interface can be configured to transmit or receive the information / signals over a wired transmission medium, such as via the fronthaul link 160 between the RU 106d and the baseband unit (BBU) 112 of the base station 104d associated with the cell 190d. The BBU 112 includes a DU 108 and a CU 110, which may also have a wired interface (e.g., midhaul link) configured between the DU 108 and the CU 110 to transmit or receive the information / signals between the DU 108 and the CU 110. In further examples, a wireless interface, which may include a receiver, a transmitter, or a transceiver, such as an RF transceiver, configured to transmit and / or receive the information / signals via the wireless transmission medium, such as for information communicated between the RU 106a of the cell 190a and the base station 104e of the cell 190e via cross-cell communication beams 136-138 of the RU 106a and the base station 104e.
[0042] The RUs 106 may be configured to implement lower layer functionality. For example, the RU 106 is controlled by the DU 108 and may correspond to a logical node that hosts RF processing functions, or lower layer PHY functionality, such as execution of fast Fourier transform (FFT) , inverse FFT (iFFT) , digital beamforming, physical random access channel (PRACH) extraction and filtering, etc. The functionality of the RU 106 may be based on the functional split, such as a functional split of lower layers.
[0043] The RUs 106 may transmit or receive over-the-air (OTA) communication with one or more UEs 102. For example, the RU 106b of the cell 190b communicates with the UE 102b of the cell 190b via a first set of communication beams 132 of the RU 106b and a second set of communication beams 134b of the UE 102b, which may correspond to inter-cell communication beams or, in some examples, cross-cell communication beams. For instance, the UE 102b of the cell 190b may communicate with the RU 106a of the cell 190a via a third set of communication beams 134a of the UE 102b and a fourth set of communication beams 136 of the RU 106a. DUs 108 can control both real-time and non-real-time features of control plane and user plane communications of the RUs 106.
[0044] Any combination of the RU 106, the DU 108, and the CU 110, or reference thereto individually, may correspond to a base station 104. Thus, the base station 104 may include at least one of the RU 106, the DU 108, or the CU 110. The base stations 104 provide the UEs 102 with access to a core network. The base stations 104 may relay communications between the UEs 102 and the core network (not shown) . The base stations 104 may be associated with macrocells for higher-power cellular base stations and / or small cells for lower-power cellular base stations. For example, the cell 190e may correspond to a macrocell, whereas the cells 190a-190d may correspond to small cells. Small cells include femtocells, picocells, microcells, etc. A network that includes at least one macrocell and at least one small cell may be referred to as a “heterogeneous network. ”
[0045] Transmissions from a UE 102 to a base station 104 / RU 106 are referred to as uplink (UL) transmissions, whereas transmissions from the base station 104 / RU 106 to the UE 102 are referred to as downlink (DL) transmissions. Uplink transmissions may also be referred to as reverse link transmissions and downlink transmissions may also be referred to as forward link transmissions. For example, the RU 106d utilizes antennas of the base station 104d of cell 190d to transmit a downlink / forward link communication to the UE 102d or receive an uplink / reverse link communication from the UE 102d based on the Uu interface associated with the access link between the UE 102d and the base station 104d / RU 106d.
[0046] Communication links between the UEs 102 and the base stations 104 / RUs 106 may be based on multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and / or transmit diversity. The communication links may be associated with one or more carriers. The UEs 102 and the base stations 104 / RUs 106 may utilize a spectrum bandwidth of Y MHz (e.g., 5, 10, 15, 20, 100, 400, 800, 1600, 2000, etc. MHz) per carrier allocated in a carrier aggregation of up to a total of Yx MHz, where x component carriers (CCs) are used for communication in each of the uplink and downlink directions. The carriers may or may not be adjacent to each other along a frequency spectrum. In examples, uplink and downlink carriers may be allocated in an asymmetric manner, with more or fewer carriers allocated to either the uplink or the downlink. A primary component carrier and one or more secondary component carriers may be included in the component carriers. The primary component carrier may be associated with a primary cell (PCell) and a secondary component carrier may be associated with a secondary cell (SCell) .
[0047] Some UEs 102, such as the UEs 102a and 102s, may perform device-to-device (D2D) communications over sidelink. For example, a sidelink communication / D2D link utilizes a spectrum for a wireless wide area network (WWAN) associated with uplink and downlink communications. Such sidelink / D2D communication may be performed through various wireless communications systems, such as wireless fidelity (Wi-Fi) systems, Bluetooth systems, Long Term Evolution (LTE) systems, New Radio (NR) systems, etc.
[0048] The UEs 102 and the base stations 104 / RUs 106 may each include a plurality of antennas. The plurality of antennas may correspond to antenna elements, antenna panels, and / or antenna arrays that may facilitate beamforming operations. For example, the RU 106b transmits a downlink beamformed signal based on a first set of communication beams 132 to the UE 102b in one or more transmit directions of the RU 106b. The UE 102b may receive the downlink beamformed signal based on a second set of communication beams 134b from the RU 106b in one or more receive directions of the UE 102b. In a further example, the UE 102b may also transmit an uplink beamformed signal (e.g., sounding reference signal (SRS) ) to the RU 106b based on the second set of communication beams 134b in one or more transmit directions of the UE 102b. The RU 106b may receive the uplink beamformed signal from the UE 102b in one or more receive directions of the RU 106b. The UE 102b may perform beam training to determine the best receive and transmit directions for the beamformed signals. The transmit and receive directions for the UEs 102 and the base stations 104 / RUs 106 may or may not be the same.
[0049] In further examples, beamformed signals may be communicated between a first base station / RU 106a and a second base station 104e. For instance, the base station 104e of the cell 190e may transmit a beamformed signal to the RU 106a based on the communication beams 138 in one or more transmit directions of the base station 104e. The RU 106a may receive the beamformed signal from the base station 104e of the cell 190e based on the RU communication beams 136 in one or more receive directions of the RU 106a. In further examples, the base station 104e transmits a downlink beamformed signal to the UE 102e based on the communication beams 138 in one or more transmit directions of the base station 104e. The UE 102e receives the downlink beamformed signal from the base station 104e based on UE communication beams 130 in one or more receive directions of the UE 102e. The UE 102e may also transmit an uplink beamformed signal to the base station 104e based on the UE communication beams 130 in one or more transmit directions of the UE 102e, such that the base station 104e may receive the uplink beamformed signal from the UE 102e in one or more receive directions of the base station 104e.
[0050] The base station 104 may include and / or be referred to as a network entity. That is, “network entity” may refer to the base station 104 or at least one unit of the base station 104, such as the RU 106, the DU 108, and / or the CU 110. The base station 104 may also include and / or be referred to as a next generation evolved Node B (ng-eNB) , a next generation NB (gNB) , an evolved NB (eNB) , an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS) , an extended service set (ESS) , a TRP, a network node, network equipment, or other related terminology. The base station 104 or an entity at the base station 104 can be implemented as an IAB node, a relay node, a sidelink node, an aggregated (monolithic) base station, or a disaggregated base station including one or more RUs 106, DUs 108, and / or CUs 110. A set of aggregated or disaggregated base stations may be referred to as a next generation-radio access network (NG-RAN) . In some examples, the UE 102a operates in dual connectivity (DC) with the base station 104e and the base station / RU 106a. In such cases, the base station 104e can be a master node and the base station / RU 160a can be a secondary node.
[0051] Uplink / downlink signaling may also be communicated via a satellite positioning system (SPS) 114. In an example, the SPS 114 associated with the cell 190c may be in communication with one or more UEs 102, such as the UE 102c, and one or more base stations 104 / RUs 106, such as the RU 106c. The SPS 114 may correspond to one or more of a Global Navigation Satellite System (GNSS) , a global position system (GPS) , a non-terrestrial network (NTN) , or other satellite position / location system. The SPS 114 may be associated with LTE signals, NR signals (e.g., based on round trip time (RTT) and / or multi-RTT) , wireless local area network (WLAN) signals, a terrestrial beacon system (TBS) , sensor-based information, NR enhanced cell ID (NR E-CID) techniques, downlink angle-of-departure (DL-AoD) , downlink time difference of arrival (DL-TDOA) , uplink time difference of arrival (UL-TDOA) , uplink angle-of-arrival (UL-AoA) , and / or other systems, signals, or sensors.
[0052] Still referring to FIG. 1, in certain aspects, any of the UEs 102 may include a M-TRP component 140 configured to receive, from a network entity, a first control signal indicating a first set of transmission configuration indicator (TCI) states. The M-TRP component 140 is configured to receive from the network entity, a second control signal scheduling a physical downlink shared channel (PDSCH) transmission for a M-TRP scheme. The second control signal is associated with a second set of TCI states. The M-TRP component 140 is configured to receive, from the network entity, the PDSCH transmission using at least one TCI state of the first set of TCI states or using the second set of TCI states based on a configuration of the second control signal. For example, the PDSCH transmission refers to a data transmission over or via the PDSCH.
[0053] In certain aspects, any of the base stations 104 or a network entity of the base stations 104 may include a configuration component 150 configured to transmit, to a UE, a first control signal indicating a first set of transmission configuration indicator (TCI) states. The configuration component 150 is configured to transmit, to the UE, a second control signal scheduling a physical downlink shared channel (PDSCH) transmission for a multiple transmission-reception point (M-TRP) scheme. The second control signal is associated with a second set of TCI states. The configuration component 150 is configured to transmit, to the UE (102) , the PDSCH transmission using at least one TCI state of the first set of TCI states or using the second set of TCI states based on a configuration of the second control signal.
[0054] Still referring to FIG. 1, in certain aspects, any of the UEs 102 may include the M-TRP component 140 configured to receive, from a network entity, a first control signal configuring UE-initiated beam selection for a multiple transmission-reception point (M-TRP) scheme. The M-TRP component 140 is configured to transmit, to the network entity, a report indicating one or more UE-selected beams based on the first control channel. The M-TRP component 140 is configured to communicate with the network entity using the one or more UE-selected beams for at least one of a channel or a reference signal for the M-TRP scheme.
[0055] In certain aspects, any of the base stations 104 or a network entity of the base stations 104 may include the configuration component 150 configured to transmit, to a UE, a first control signal configuring UE-initiated beam selection for a multiple transmission-reception point (M-TRP) scheme. The configuration component 150 is configured to receive, from the UE, a report indicating one or more UE-selected beams based on the first control channel. The configuration component 150 is configured to communicate with the UE using the one or more UE-selected beams for at least one of a channel or a reference signal for the M-TRP scheme.
[0056] Still referring to FIG. 1, in certain aspects, any of the UEs 102 may include the M-TRP component 140 configured to receive, from a network entity, a control signal including a first field or a second field different from the first field in a physical downlink control channel (PDCCH) order. In some examples, the first field indicates that the PDCCH order is for triggering contention-free random access (CFRA) for a serving cell or a neighboring cell. In some examples, the first field indicates that the PDCCH order is for triggering the CFRA for the serving cell or a candidate cell. The second field indicates that the PDCCH order is for triggering a lower-layer triggered mobility (LTM) procedure for the serving cell or a candidate cell. The M-TRP component 140 is configured to communicate with the network entity based on at least one of the first field or the second field of the control signal.
[0057] In certain aspects, any of the base stations 104 or a network entity of the base stations 104 may include the configuration component 150 configured to transmit, to a UE, a control signal including a first field or a second field different from the first field in a physical downlink control channel (PDCCH) order. In some examples, the first field indicates that the PDCCH order is for triggering contention-free random access (CFRA) for a serving cell or a neighboring cell. In some examples, the first field indicates that the PDCCH order is for triggering the CFRA for the serving cell or a candidate cell. The second field indicates that the PDCCH order is for triggering a lower-layer triggered mobility (LTM) procedure for the serving cell or a candidate cell. The configuration component 150 is configured to communicates with the UE based on at least one of the first field or the second field of the control signal.
[0058] Accordingly, FIG. 1 describes a wireless communication system that may be implemented in connection with aspects of one or more other figures described herein. Further, although the following description may be focused on 5G NR, the concepts described herein may be applicable to other similar areas, such as 5G-Advanced and future versions, LTE, LTE-advanced (LTE-A) , and other wireless technologies, such as 6G. It is also noted that the ideas, concepts or embodiments throughout the document may be applied for issue (s) or procedure (s) with similar consideration (s) or regard (s) in LTE / NR / 6G or other RATs.
[0059] FIG. 2A illustrates a diagram of an example system 100b with a distributed base station and / or a UE according to an embodiment. Referring to FIG. 2A, an example of wireless communication system 200 includes a UE 102, a base station (BS) 104a, a base station 104b, and a core network (CN) 115. The base stations 104a and 104b can operate in a RAN 105 connected to the core network (CN) 115. The CN 115 can be implemented as an evolved packet core (EPC) 111 or a fifth generation (5G) core (5GC) 160, for example. The CN 115 can also be implemented as a sixth generation (6G) core in another example.
[0060] The base station 104a can cover one or more cells (e.g., cells 124 and 125) with one or more transmit and / or receive points (TRPs) , and the base station 104b can similarly cover one or more cells (e.g., cell 126) with one or more TRPs. For example, the base station 104a operates cell 124 with TRPs 107-1 and 107-2 and operates cell 125 with TRP 107-3, and the base station 104b operates cell 126 with TRPs 109-1 and 109-2. The cells 124 and 125 are operated on the same carrier frequency / frequencies. The cell 126 can be operated on the same carrier frequency / frequencies as the cells 124 and 125. Alternatively, the cell 126 can be operated on different carrier frequency / frequencies from the cells 124 and 125. In some implementations, the base station 104a connects each of the TRPs 107-1, 107-2 and 107-3 via a fiber connection or an Ethernet connection. If the base station 104a is a gNB, the cells 124 and 125 are NR cells. If the base station 104a is an (ng-) eNB, the cells 124 and 125 are evolved universal terrestrial radio access (EUTRA) cells. Similarly, if the base station 104b is a gNB, the cell 126 is an NR cell, and if the base station 104b is an (ng-) eNB, the cell 126 is an EUTRA cell. The cells 124, 125, and 126 can be in the same Radio Access Network Notification Areas (RNA) or different RNAs. In general, the RAN 105 can include any number of base stations, and each of the base stations can cover one, two, three, or any other suitable number of cells. The UE 102 can support at least a 5G NR (or simply, “NR” ) or E-UTRA air interface to communicate with the base station 104a via the TRP 107-1, TRP 107-2 and / or TRP-3. Similarly, the UE 102 can support at least a 5G NR (or simply, “NR” ) or E-UTRA air interface to communicate with the base station 104b via the TRP 109-1 and / or TRP 109-2. Each of the base stations 104a, 104b can connect to the CN 115 via an interface (e.g., S1 or NG interface) . The base stations 104a and 104b also can be interconnected via an interface (e.g., X2 or Xn interface) for interconnecting NG RAN nodes.
[0061] When a base station (e.g., the base station 104a or 104b) transmits DL data via a TRP (e.g., the TRP 107-1, TRP 107-2, TRP 107-3, TRP 109-1 or TRP 109-2) , the base station 104a can generate a packet including the data transmit the packet to the TRP 107-1. For example, the packet can be a fronthaul transport protocol data unit. The TRP extracts the data from the packet and transmits the data. In some implementations, the base station 104a can include control information for time-critical control and management information directly related to the data in the packet, and the TRP can transmit the data in accordance with the control information. In some implementations, the data includes In-phase and Quadrature (IQ) data, a physical layer bit sequence, or a MAC PDU. When the TRP receives data from a UE (e.g., UE 102) , the TRP generates a packet including the data and transmit the packet to the base station 104a. In some implementations, the data includes IQ data, a physical layer bit sequence, or a MAC PDU.
[0062] Among other components, the EPC 111 can include a Serving Gateway (SGW) 118, a Mobility Management Entity (MME) 113, and a Packet Data Network Gateway (PGW) 116. The SGW 118 in general is configured to transfer user-plane packets related to audio calls, video calls, Internet traffic, etc., and the MME 113 is configured to manage authentication, registration, paging, and other related functions. The PGW 116 provides connectivity from the UE 102 to one or more external packet data networks, e.g., an Internet network and / or an Internet Protocol (IP) Multimedia Subsystem (IMS) network. The 5GC 160 includes a User Plane Function (UPF) 162 and an Access and Mobility Management Function (AMF) 164, and / or Session Management Function (SMF) 166. Generally, the UPF 162 is configured to transfer user-plane packets related to audio calls, video calls, Internet traffic, etc., the AMF 164 is configured to manage authentication, registration, paging, and other related functions, and the SMF 166 is configured to manage PDU sessions.
[0063] As illustrated in FIG. 2A, the base station 104a supports cells 124 and 125, and the base station 104b supports a cell 126. The cells 124, 125, and 126 can partially overlap, so that the UE 102 can select, reselect, or hand over from one of the cells 124, 125, and 126 to another. To directly exchange messages or information, the base station 104a and base station 104b can support an X2 or Xn interface. In general, the CN 115 can connect to any suitable number of base stations supporting NR cells and / or EUTRA cells.
[0064] The base station 104a is equipped with processing hardware 230 that can include one or more general-purpose processors (e.g., CPUs) and a non-transitory computer-readable memory storing instructions that the one or more general-purpose processors execute. Additionally or alternatively, the processing hardware 230 can include special-purpose processing units. The processing hardware 230 can include a PHY controller 232 configured to transmit data and control signal on physical DL channels and DL reference signals with one or more user devices (e.g. UE 102) via one or more TRPs (e.g., TRP 107-1, TRP 107-2 and / or TRP 107-3) . The PHY controller 232 is also configured to receive data and control signal on physical UL channels and / or UL reference signals with the one or more user devices via the one or more TRPs (e.g., TRP 107-1, TRP 107-2 and / or TRP 107-3) . The processing hardware 230 in an example implementation includes a MAC controller 234 configured to perform a random access (RA) procedure with one or more user devices, manage UL timing advance for the one or more user devices, receive UL MAC PDUs from the one or more user devices, and transmit DL MAC PDUs to the one or more user devices. The processing hardware 230 can further include an RRC controller 236 to implement procedures and messaging at the RRC sublayer of the protocol communication stack. The base station 104b can include processing hardware 240 that is similar to processing hardware 230. In particular, components 242, 244, and 246 can be similar to the components 232, 234, and 236, respectively.
[0065] The UE 102 is equipped with processing hardware 250 that can include one or more general-purpose processors such as CPUs and non-transitory computer-readable memory storing machine-readable instructions executable on the one or more general-purpose processors, and / or special-purpose processing units. The PHY controller 252 is also configured to receive data and control signal on physical DL channels and / or DL reference signals with the base station 104a or 104b via one or more TRPs (e.g., TRP 107-1, TRP 107-2, TRP 107-3, TRP 109-1 and / or TRP 109-2) . The PHY controller 252 is also configured to transmit data and control signal on physical UL channels and / or UL reference signals with the base station 104a or 104b via the one or more TRPs (e.g., TRP 107-1, TRP 107-2, TRP 107-3, TRP 109-1 and / or TRP 109-2) . The processing hardware 250 in an example implementation includes a MAC controller 254 configured to perform a random access procedure with base station 104a or 104b, manage UL timing advance for the one or more user devices, transmit UL MAC PDUs to the base station 104a or 104b, and receive DL MAC PDUs from the base station 104a or 104b. The processing hardware 250 can further include an RRC controller 256 to implement procedures and messaging at the RRC sublayer of the protocol communication stack.
[0066] FIG. 2B illustrates a diagram of an example base station including a central unit (CU) and a distributed unit (DU) of a distributed base station in the system of FIG. 1B according to an embodiment. In FIG. 2B, an example distributed or disaggregated implementation of one or both of the base stations 104a, 104b is illustrated. In this implementation, each of the base station 104a and / or 104b includes a central unit (CU) 110 and one or more distributed units (DUs) 108. The CU 110 includes processing hardware, such as one or more general-purpose processors (e.g., CPUs) and a computer-readable memory storing machine-readable instructions executable on the general-purpose processor (s) , and / or special-purpose processing units. For example, the CU 110 can include a PDCP controller (e.g., PDCP controller 234, 244) , an RRC controller (e.g., RRC controller 236, 246) , and / or an RRC inactive controller (e.g., RRC inactive controller 138, 148) . In some implementations, the CU 110 can include an RLC controller configured to manage or control one or more RLC operations or procedures. In other implementations, the CU 110 does not include an RLC controller.
[0067] Each of the DUs 108 also includes processing hardware that can include one or more general-purpose processors (e.g., CPUs) and computer-readable memory storing machine-readable instructions executable on the one or more general-purpose processors, and / or special-purpose processing units. For example, the processing hardware can include a MAC controller (e.g., MAC controller 232, 242) configured to manage or control one or more MAC operations or procedures (e.g., a random access procedure) , and / or an RLC controller configured to manage or control one or more RLC operations or procedures. The processing hardware can also include a physical layer controller configured to manage or control one or more physical layer operations or procedures.
[0068] In some implementations, the RAN 105 supports Integrated Access and Backhaul (IAB) functionality. In some implementations, the DU 108 operates as an (IAB) -node, and the CU 110 operates as an IAB-donor.
[0069] In some implementations, the CU 110 can include a logical node CU-CP 110A that hosts the control plane part of the PDCP protocol of the CU 110. The CU 110 can also include logical node (s) CU-UP 110B that hosts the user plane part of the PDCP protocol and / or SDAP protocol of the CU 110. The CU-CP 110A can transmit control information (e.g., RRC messages, F1 application protocol messages) , and the CU-UP 110B can transmit data packets (e.g., SDAP PDUs or IP packets) .
[0070] The CU-CP 110A can be connected to multiple CU-UPs 110B through the E1 interface. The CU-CP 110A selects the appropriate CU-UP 110B for the requested services for the UE 102. In some implementations, a single CU-UP 110B can be connected to multiple CU-CPs 110A through the E1 interface. If the CU-CP 110A and DU (s) 108 belong to a gNB, the CU-CP 110A can be connected to one or more DU 108s through an F1-C interface and / or an F1-U interface. If the CU-CP 110A and DU(s) 108 belong to an ng-eNB, the CU-CP 110A can be connected to DU (s) 108 through a W1-C interface and / or a W1-U interface. In some implementations, one DU 108 can be connected to multiple CU-UPs 110B under the control of the same CU-CP 110A. In such implementations, the connectivity between a CU-UP 110B and a DU 108 is established by the CU-CP 110A using Bearer Context Management functions.
[0071] FIG. 3A illustrates, in a simplified manner, an example protocol stack 300 according to which the UE 102 can communicate with an eNB / ng-eNB or a gNB (e.g., one or both of the base stations 104a, 104b) . In the example stack 300, a physical layer (PHY) 202A of EUTRA provides transport channels to the EUTRA MAC sublayer 204A, which in turn provides logical channels to the EUTRA RLC sublayer 206A. The EUTRA RLC sublayer 206A in turn provides RLC channels to a EUTRA PDCP sublayer 208 and, in some cases, to an NR PDCP sublayer 210. Similarly, the NR PHY 202B provides transport channels to the NR MAC sublayer 204B, which in turn provides logical channels to the NR RLC sublayer 206B. The NR RLC sublayer 206B in turn provides data transfer services to the NR PDCP sublayer 210. The NR PDCP sublayer 210 in turn can provide data transfer services to the SDAP sublayer 212 or an RRC sublayer (not shown in FIG. 3A) . The UE 102, in some implementations, supports both the EUTRA and the NR stack as shown in FIG. 3A, to support handover between EUTRA and NR base stations and / or to support dual connectivity (DC) over EUTRA and NR interfaces. Further, as illustrated in FIG. 3A, the UE 102 can support layering of NR PDCP 210 over EUTRA RLC 206A, and SDAP sublayer 212 over the NR PDCP sublayer 210.
[0072] The EUTRA PDCP sublayer 208 and the NR PDCP sublayer 210 receive packets (e.g., from an IP layer, layered directly or indirectly over the PDCP layer 208 or 210) that can be referred to as SDUs, and output packets (e.g., to the RLC layer 206A or 206B) that can be referred to as PDUs. Except where the difference between SDUs and PDUs is relevant, this disclosure for simplicity refers to both SDUs and PDUs as “packets. ”
[0073] On a control plane, the EUTRA PDCP sublayer 208 and the NR PDCP sublayer 210 can provide signaling radio bearers (SRBs) to the RRC sublayer (not shown in FIG. 3A) to exchange RRC messages or NAS messages, for example. On a user plane, the EUTRA PDCP sublayer 208 and the NR PDCP sublayer 210 can provide data radio bearers (DRBs) to support data exchange. Data exchanged on the NR PDCP sublayer 210 can be SDAP PDUs, IP packets, or Ethernet packets.
[0074] FIG. 3B illustrates a diagram of another example protocol stack according to an embodiment. It is possible to functionally split the radio protocol stack, as shown by the radio protocol stack 350 in FIG. 3B. The CU at one or both of the base stations 104a, 104b can hold all the control and upper layer functionalities (e.g., RRC 214, SDAP 212, NR PDCP 210) , while the lower layer operations (e.g., NR RLC 206B, NR MAC 204B, and NR PHY 202B) are delegated to the DU. To support connection to a 5GC, NR PDCP 210 provides SRBs to RRC 214, and NR PDCP 210 provides DRBs to SDAP 212 and SRBs to RRC 214.
[0075] FIG. 4 is a signaling diagram 400 illustrating communications between a UE 102 and a network entity 104 for a PDSCH transmission according to an embodiment. The network entity 104 may correspond to a base station or a unit of a base station, such as the RU 106, the DU 108, the CU 110, etc. The network entity 104 may communicate with the UE 102 via TRP 107-1, 107-2 or 107-3. The PDSCH transmission may refer to a data transmission over a PDSCH.
[0076] The network entity 104 may configure some CORESET or PDCCHs to not use or follow or apply the indicated unified TCI state (s) . For example, the network entity 104 may configure CORESET#0 or CORESET (s) at least associated with commons search space (CSS) sets to not use or follow or apply the indicated unified TCI state (s) . Usually, the PDSCH transmission scheduled by the CORESET#0 or CORESET (s) associated with the CSS sets would carry common signal, e.g., broadcast signal. Such PDSCH transmission is also received by other UEs in the same physical serving cell. Thus, when the PDSCH transmission is scheduled by these CORESETs, it may be of increased complexity to determine whether the scheduled PDSCH transmission can use (e.g., apply or follow) the unified TCI states.
[0077] Referring to FIG. 4, the UE 102 may transmit or report 410 UE capability (s) for supporting unified TCI states for the M-TRP scheme. The network entity 104 may receive 410 the UE capability (s) for supporting the unified TCI states for the M-TRP scheme. Then, the network entity 104 may transmit 420 a first RRC message including an RRC configuration for configuring a list of TCI state (s) , e.g., one or more joint / DL TCI state (s) . The network entity 104 may then transmit 430 a second RRC message including an RRC configuration for configuring which indicated joint / DL TCI state (s) are applied for the PDSCH. In some implementations, the first RRC message and the second RRC message may be the same RRC message. Then, the network entity 104 transmits 440 a medium access control-control element (MAC-CE) activating a subset of joint / DL TCI state (s) (e.g., a number of joint / DL TCI state (s) ) from the list of joint / DL TCI state (s) (e.g., the configured joint / DL TCI state (s) ) . The UE 104 receives 440 the MAC-CE activating a subset of joint / DL TCI state (s) from the list of joint / DL TCI state (s) . Afterwards, the network entity 104 may transmit 450 a DCI indicating one or more joint / DL TCI state (s) from the activated joint / DL TCI state (s) . The UE 102 may receive 450 the DCI indicating the one or more joint / DL TCI state (s) from the activated joint / DL TCI state (s) . If the MAC-CE only activates one joint / DL TCI state or only indicates two joint / DL TCI state (s) , each of which is associated with different TRP or TRP identifier, the two activated joint / DL TCI states are the first indicated joint / DL TCI state and the second indicated joint / DL TCI state respectively. In such case, transmitting the DCI 450 can be skipped. The activated or indicated joint / DL TCI state (s) may be referred as a first set of TCI states. The first set of TCI states may include the activated subset of joint / DL TCI state (s) from the list of joint / DL TCI state (s) (e.g., by the MAC-CE) or the indicated one or more joint / DL TCI state (s) from the activated joint / DL TCI state (s) (e.g., by the DCI) . The MAC-CE which activates the subset of joint / DL TCI state (s) from the list of joint / DL TCI state (s) or the DCI which indicates the one or more joint / DL TCI state (s) from the activated joint / DL TCI state (s) may be referred as a first control signal. The first control signal may include the MAC-CE which activates the subset of joint / DL TCI state (s) from the list of joint / DL TCI state (s) or the DCI which indicates the one or more joint / DL TCI state (s) from the activated joint / DL TCI state (s) .
[0078] Then, the network entity 104 transmits 460 a PDCCH transmission in a CORESET scheduling the PDSCH transmission. The UE 102 receives 460 the PDCCH transmission in the CORESET scheduling the PDSCH transmission. The PDCCH transmission may refer to a transmission over a PDCCH. The scheduling PDCCH transmission may comprise a DCI with a DCI format 1_0 or a DCI format 1_1 / 1_2. The PDCCH transmission (e.g., DCI) in the scheduling CORESET (i.e., a CORESET with the scheduling PDCCH / DCI) may not use or apply or follow the indicated joint / DL TCI state (s) . The one or more TCI states for receiving the PDCCH transmission (e.g., DCI) in the scheduling CORESET may be referred as a second set of TCI states. The second set of TCI states is for receiving the scheduling CORESET (e.g., the PDCCH transmission or the DCI) . In some examples, the second set of TCI states is different than the first set of TCI states. In some other examples, the second set of TCI states are the same as the first set of TCI states.
[0079] The UE 102 and / or the BS 104 determine (s) 470 whether and how to use / apply the activated or indicated joint / DL TCI state (s) to receive the PDSCH transmission based on a configuration of the scheduling PDCCH transmission. In some examples, the configuration of the scheduling PDCCH transmission includes whether the scheduling CORESET (i.e., a CORESET with the scheduling PDCCH / DCI) applies / follows the indicated joint / DL TCI state (s) . The configuration of the scheduling PDCCH transmission may include whether the second set of TCI states is different than the first set of TCI states. The configuration of the scheduling PDCCH may further include a DCI format including the DCI format 1_0 or the DCI format 1_1 / 1_2.
[0080] Afterwards, the network entity 104 transmits 480 the PDSCH transmission scheduled by the PDCCH in the CORESET based on the configuration of the scheduling PDCCH transmission. The UE 102 receives 480 the PDSCH transmission scheduled by the PDCCH in the CORESET based on the configuration of the scheduling PDCCH transmission.
[0081] In some examples, a TRP (e.g., TRP 107-1, TRP 107-2, TRP 107-3, TRP 109-1 and / or TRP 109-2) may be associated with or identified by a TRP identifier. In some implementations, a NW entity (e.g., the base station 104a or 104b) includes or configures a TRP identifier in UL configuration (s) that the NW entity transmits to a UE (e.g., the UE 102) for UL transmission (s) via a TRP identified by the TRP identifier. In some implementation, the UL configuration (s) include downlink control information (DCI) transmitted on a PDCCH, and / or physical uplink shared channel (PUSCH) configuration, physical uplink control channel (PUCCH) configuration and / or sounding reference signal (SRS) configuration included in a RRC message (e.g., RRC reconfiguration message or a RRC resume message) that the NW entity transmits to the UE. In some implementations, the UL transmission (s) include PUSCH transmission (s) , PUCCH transmission (s) and / or SRS transmission (s) . In some implementations, the NW entity includes a TRP identifier in DL configuration (s) that the NW entity transmits to the UE 102 for DL transmission (s) via a TRP identified by the TRP identifier. In one implementation, the DL configuration (s) include DCI transmitted on a PDCCH, and / or channel state information (CSI) resource configuration, physical downlink shared channel (PDSCH) configuration (s) and / or physical downlink control channel (PDCCH) configuration (s) included in a RRC message (e.g., RRC reconfiguration message or a RRC resume message) that the NW entity transmits to the UE. In some implementations, the DL transmission (s) include CSI reference signal (CSI-RS) transmission (s) , synchronization signal block (SSB) transmission (s) , PDSCH transmission (s) and / or PDCCH transmission (s) .
[0082] In some examples, the NW entity does not transmit / configure a TRP identifier to the UE and uses an implicit indication to indicating a TRP to the UE. In one implementation, the implicit indication can be one of the following configuration parameters: a CORESETPoolIndex, a value (candidate) of a CORESETPoolIndex, dataScramblingIdentityPDSCH, dataScramblingIdentityPDSCH2-r16, or PUCCH-ResourceGroup-r16. In such implementations, the UE derives a TRP (identifier) from the implicit indication. In some implementations, the NW entity transmits a RRC message (e.g., RRC reconfiguration message or a RRC resume message) including the configuration parameters to the UE.
[0083] In some examples, the NW entity configures or indicates the UE a first TRP identifier. In some implementations, the UE derives a first TRP identifier (value) . In some implementations, the NW entity configures or indicates the UE a second TRP identifier (value) . In some implementations, the UE derives a second TRP identifier (value) . In some implementations, the first TRP identifier can be associated with the first TRP. In some implementations, the second TRP identifier can be associated with the second TRP.
[0084] In some implementations, the NW entity configures that a serving cell is associated with the first TRP or the first TRP identifier (value) . In some implementations, the NW entity configures a first control resource set (CORESET) associated with the serving cell or first TRP. The NW entity can configure CORESETPoolIndex #0 to identify the first CORESET. In one implementation, the NW entity can transmit to the UE a RRC message (e.g., a RRC setup message, a RRC reconfiguration message or a RRC resume message) configuring the first CORESET and / or including the CORESETPoolIndex #0. Thus, the UE monitors a PDCCH on the first CORESET to receive DCIs from the NW entity, which implies that the UE monitors a PDCCH or receives DCIs via the first TRP from the NW entity (i.e., from the first TRP) . In such a case, the UE determines that CORESETPoolIndex #0 indicates a TRP (i.e., the first TRP) of the NW entity.
[0085] In one implementation, the NW entity configures that the serving cell associated with the second TRP or the second TRP identifier (value) . In other implementation, the second TAG is associated with a non-serving cell, and the NW entity indicates or configures the association in a RRC message. In one implementation, the NW entity configures the non-serving cell associated with the second TRP or the second TRP identifier (value) . In some implementations, the NW entity configures a second CORESET is associated with the serving cell, non-serving cell or second TRP. The NW entity can configure CORESETPoolIndex #1 to identify the second CORESET. In one implementation, the NW entity can transmit to the UE a RRC message (e.g., a RRC setup message, a RRC reconfiguration message or a RRC resume message) configuring the second CORESET and / or including the CORESETPoolIndex #1. Thus, the UE monitors a PDCCH on the second CORESET to receive DCIs from the NW entity, which implies that the UE monitors a PDCCH or receives DCIs via the second TRP from the NW entity (i.e., from the second TRP) . In such a case, the UE determines that CORESETPoolIndex #1 indicates a TRP (i.e., the second TRP) .
[0086] In some implementations, the NW entity can configure the UE one or more TCI state lists for a component carrier (CC) of a serving cell, where the CC could be PCell or SCell. For example, the NW entity can configure a joint TCI state list for a CC of a serving cell. For example, the NW entity can configure a DL TCI state list and / or a UL TCI state list for a CC of a serving cell. One joint TCI state list can comprise one or more joint TCI states. One DL TCI state list can comprise one or more DL TCI states. One UL TCI state list can comprise one or more UL TCI states.
[0087] In some implementations, the NW entity can configure the UE a first RRC parameter unifiedTCI-StateType. The first RRC parameter unifiedTCI-StateType can be a per-serving-cell configuration. The first RRC parameter unifiedTCI-StateType can indicate which type of TCI state list (s) for a serving cell. For example, the first RRC parameter unifiedTCI-StateType can indicate “joint” or “separate” . The first RRC parameter unifiedTCI-StateType can provide one or more the following purpose: if the first RRC parameter for a CC of serving cell indicates “joint” , the NW entity could explicitly or implicitly configure the UE one or more joint TCI state list (s) for the CC of serving cell or the UE; if the first RRC parameter for a CC of serving cell indicates “separate” , the NW entity could explicitly or implicitly configure the UE one or more DL TCI state list (s) for the CC of serving cell; and / or if the first RRC parameter for a CC of serving cell indicates “separate” , the NW entity could explicitly or implicitly configure the UE one or more UL TCI state list (s) for the CC of serving cell.
[0088] In some examples, if the NW entity explicitly configures the UE one or more TCI state list (s) for a CC of a serving cell, it could imply that the NW entity configures the one or more TCI state list (s) (explicitly) under RRC configuration (e.g., ServingCellConfig) for a CC of the serving cell.
[0089] In some examples, if the NW entity implicitly configures the UE one or more TCI state list (s) for a CC of serving cell, it could imply at least one of the followings: the NW entity configures the one or more TCI state list (s) under RRC configuration (e.g., ServingCellConfig) for other serving cell (s) / CCs or a reference serving cell / CC; the UE refers the one or more TCI state list (s) for other serving cell (s) / CCs or a reference serving cell / CC; and / or the UE determines that the one or more TCI state list (s) , which is for other serving cell / CCs or a reference serving cell / CC, is also for the CC of the serving cell.
[0090] In some examples, the NW entity can transmit a first MAC-CE (e.g., transmitting 440 the MAC-CE) to the UE when or after the NW entity configures the UE one or more TCI state list (s) for the CC of serving cell; and / or the UE refers or determines one or more TCI state list (s) for the CC of serving cell.
[0091] In some examples, the first MAC-CE can activate or indicate one or more TCI states from the one or more TCI state list (s) . The one or more TCI states activated / indicated by the first MAC-CE can map to one or more TCI codepoints in a TCI field. In some cases, the UE can (directly) apply or use the one or more TCI states activated / indicated by the first MAC-CE for performing DL and / or UL transmission (subsequently) .
[0092] In some examples, if the number of TCI states activated / indicated by the first MAC-CE is larger than one, those TCI states activated / indicated by the first MAC-CE can map to one or more TCI codepoints in a TCI field in a DCI. In some implementations, if the number of TCI states activated / indicated by the first MAC-CE is one, the UE can (directly) apply or use the TCI state activated / indicated by the first MAC-CE for performing DL and / or UL transmission (subsequently) . In some implementations, if the number of TCI states activated / indicated by the first MAC-CE is two, and / or if the two TCI states activated / indicated by the first MAC-CE are associated with different TRP identifier or applicable for different TRP, the UE can (directly) apply or use these two TCI states activated / indicated by the first MAC-CE for performing corresponding DL and / or UL transmission (subsequently) .
[0093] In some examples, one TCI state can be mapped to one TCI codepoint, based on the first MAC-CE. In some cases, more than one TCI states can be mapped to one TCI codepoint, based on the first MAC-CE. In some cases, the TCI codepoint can indicate one of the followings: one or more joint TCI states (some could be TCI states associated with the first TRP (identifier) , the other could be TCI states associated with the second TRP (identifier) ) , one or more DL TCI states (some could be TCI states associated with the first TRP (identifier) , the other could be TCI states associated with the second TRP (identifier) ) , one or more UL TCI states (some could be TCI states associated with the first TRP (identifier) , the other could be TCI states associated with the second TRP (identifier) ) , or one or more DL TCI states and one or more UL TCI states (some could be TCI states associated with the first TRP (identifier) , the other could be TCI states associated with the second TRP (identifier) ) .
[0094] In some examples, the number of joint TCI states indicated in a TCI codepoint by the NW entity can be up to 4. In some cases, the number of DL TCI states indicated in a TCI codepoint by the NW entity can be up to 4. In some cases, the number of UL TCI states indicated in a TCI codepoint by the NW entity can be up to 4.
[0095] For example, one of the followings can be mapped to a TCI codepoint: one joint TCI state associated with the first TRP (identifier) , the other one joint TCI state associated with the second TRP (identifier) ; one DL TCI state associated with the first TRP (identifier) , one UL TCI state associated with the second TRP (identifier) ; one DL TCI state associated with the first TRP (identifier) , the other one DL TCI state associated with the second TRP (identifier) ; one UL TCI state associated with the first TRP (identifier) , the other one UL TCI state associated with the second TRP (identifier) ; one DL TCI state and one UL TCI state associated with the first TRP (identifier) , one joint TCI state associated with the second TRP (identifier) ; one DL TCI state and one UL TCI state associated with the first TRP (identifier) , one DL TCI state associated with the second TRP (identifier) ; or one DL TCI state and one UL TCI state associated with the first TRP (identifier) , one ULTCI state associated with the second TRP (identifier) .
[0096] In some examples, the UE can receive a first DCI (e.g., receiving 450 the DCI) indicating one or more TCI states. The first DCI can indicate one or more TCI states by the TCI field in the first DCI. In response to receiving the first DCI, the UE can transmit, to the NW entity, a first acknowledgement signal via a PUCCH or PUSCH transmission. In response to transmitting the first acknowledgement signal, the UE can apply or use the one or more TCI states activated / indicated by the first DCI for performing DL and / or UL transmission. In some cases, in response to transmitting the first acknowledgement signal, the UE can apply or use the one or more TCI states activated / indicated by the first DCI for performing DL and / or UL transmission, after a first application time period. In some cases, the UE can apply or use the one or more TCI states activated / indicated by the first DCI for performing DL and / or UL transmission, starting from a first slot.
[0097] In some examples, the first slot can be the earliest slot that is at least the first application time period after the last symbol of the PUCCH or PUSCH transmission. In some cases, the earliest slot (for determining the first slot) and / or the first application time period can be determined based on the active BWP with the smallest SCS among the active BWP (s) of the carrier / serving cell (s) applying the one or more TCI states. In some cases, the first application time period can be in unit of one of the followings: symbol, sub-slot, slot, sub-frame, frame, ms, or second. In some cases, the first application time period can be beamAppTime.
[0098] In some examples, the UE can receive the first MAC-CE indicating one or more TCI states. For example, the first MAC-CE may indicate one TCI state. For example, the first MAC-CE may indicate more than one TCI states, each of them can be associated with different TRP or TRP identifier. For example, the first MAC-CE may indicate two TCI states, where one is associated with the first TRP (identifier) and the other is associated with the second TRP (identifier) . In such cases, the UE may not receive a DCI indicating one or more TCI states for applying for subsequent DL and / or UL transmission. In response to receiving the first MAC-CE, the UE may transmit, to the NW entity, a second acknowledgement signal via a PUCCH or PUSCH transmission. In response to transmitting the second acknowledgement signal, the UE may apply or use the one or more TCI states activated / indicated by the first MAC-CE for performing DL and / or UL transmission. In some cases, in response to transmitting the second acknowledgement signal, the UE may apply or use the one or more TCI states activated / indicated by the first MAC-CE for performing DL and / or UL transmission, after a second application time period. In some cases, the UE may apply or use the one or more TCI states activated / indicated by the first MAC-CE for performing DL and / or UL transmission, starting from a second slot.
[0099] In some examples, the second slot can be the earliest slot that is at least the second application time period after the (last) slot of the PUCCH or PUSCH transmission. In some cases, the second application time period can be In some cases, μ can be the SCS configuration for the PUCCH or PUSCH transmission; can be the subcarrier spacing configuration for kmax with a value of 0 for frequency range 1, and kmax is provided by K-Mac or kmac=0 if K-Mac is not provided.
[0100] In some examples, the NW entity may transmit a DCI (e.g., the first DCI) to indicate a first joint / DL / UL TCI state and / or a second joint / DL / UL TCI state to the UE, e.g., by TCI field in the DCI. In some cases, the first joint / DL / UL TCI state and / or the second joint / DL / UL TCI state may be from the one or more TCI states activated by the first MAC-CE. In some other implementations, the NW entity may transmit a MAC-CE (e.g., the first MAC-CE) to indicate a first joint / DL / UL TCI state and / or a second joint / DL / UL TCI state to the UE, that is, activation of only a first joint / DL / UL TCI state and / or a second joint / DL / UL TCI state. The first joint / DL / UL TCI state may be referred to as a first joint TCI state or a first DL TCI state or a first UL TCI state. The second joint / DL / UL TCI state may be referred to as a second joint TCI state or a second DL TCI state or a second UL TCI state. In some cases, the first joint / DL TCI state may be associated with a first TRP or a first TRP identifier. In some cases, the second joint / DL TCI state may be associated with a second TRP or a second TRP identifier.
[0101] In some examples, the NW entity could configure the UE one or more additional PCI. The one or more additional PCI (s) could correspond to one or more neighboring cell (s) around the physical serving cell of the UE. In some cases, an additional PCI could be a physical cell index or a logical index corresponding to a physical cell index of a neighboring cell. If a CORESET or a TCI state or a RRC configuration is associated with or includes an additional PCI, it could imply that the CORESET or TCI state or RRC configuration is associated with or applied for or transmitted from a neighboring cell corresponding to the additional PCI.
[0102] In some examples, the NW entity could configure the UE one or more candidate cell configuration (s) . The one or more candidate cell configuration (s) could include information of neighboring cell (s) or non-serving cell (s) of the UE. The one or more candidate cell configuration (s) could include information of candidate target cell of the UE for performing a LTM procedure. A candidate cell configuration could comprise or be one of a RRCReconfiguration message, a CellGroupConfig IE or a SpCellConfig IE. A candidate cell could be current configured / activated secondary cell (SCell) of the UE.
[0103] In some examples, the candidate cell configuration could comprise at least one of the followings: a candidate cell configuration ID, a PCI or a logical index of PCI (e.g., PCI index) , one or more TCI state lists for a candidate cell, a configuration for DL RS (s) (e.g., SSB or CSI-RS) for measuring L1-RSRP and / or L1-SINR for / in a candidate cell, or a configuration for UL RS (s) (e.g., SRS) for measuring UL CSI for / in a candidate cell.
[0104] In some examples, the NW entity may transmit the UE a cell switch command. In one example, the NW entity may transmit the cell switch command via MAC-CE or PDSCH. In some implementations, the UE may receive a second DCI from the NW entity. The second DCI could schedule a PDSCH carrying the CSC.
[0105] In some examples, the cell switch command could indicate a target cell. In some implementations, the cell switch command may comprise a candidate cell configuration ID. It is noted that throughout this disclosure, a target cell may be or stand for a candidate cell indicated by a cell switch command. In response to receiving the cell switch command or after the action time of the cell switch command, the UE may perform LTM procedure based on the cell switch command. The UE may determine target cell and / or its corresponding configuration based on the candidate cell configuration ID indicated in the cell switch command. Upon completing the LTM procedure, the target cell indicated by the cell switch command may become a new serving cell or a PCell. Upon completing the LTM procedure, the UE moves from the source cell to the target cell. It is noted that throughout this disclosure, the source cell may be or stand for the (original or previous) serving cell before receiving the CSC or completing LTM procedure.
[0106] In some examples, the CSC could comprise or carry at least one of the following information or field (s) : information to identify target cell (s) , TA related information, a beam indication for target cell (for example, one joint or one pair of UL and DL unified TCI state (index) ) , active DL / UL BWP (s) for target cell or candidate cell, an instruction to trigger aperiodic TRS transmitted from target cell, where the aperiodic TRS may be quasi-co-located (QCLed) with the downlink reference signal configured in the beam indication signaling for target cell, if beam indication signaling for target cell exists in the first CSC, an instruction to trigger CSI acquisition of target cell and corresponding report to target cell, an instruction to trigger aperiodic CSI-RS for pathloss measurement for uplink power control, where the aperiodic CSI-RS may be quasi-co-located (QCLed) with the downlink reference signal configured in the beam indication signaling for target cell, if beam indication signaling for target cell exists in the first CSC, an instruction to trigger aperiodic SRS transmission to target cell, or a C-RNTI.
[0107] In some examples, the NW entity may configure the UE a common CORESET, which may be one of the following CORESET:
[0108] - a CORESET at least associated with a Type0-PDCCH CSS set on the primary cell of the MCG,
[0109] ○ in some cases, the Type0-PDCCH CSS set may be configured by pdcch-ConfigSIB1 in MIB or by searchSpaceSIB1 in PDCCH-ConfigCommon or by searchSpaceZero in PDCCH-ConfigCommon for a DCI format 1_0 with CRC scrambled by a SI-RNTI,
[0110] ○ in some cases, the Type0-PDCCH CSS set may be configured by searchSpaceZero by providing searchSpaceID=0 for searchSpaceMCCH or searchSpaceMTCH for a DCI format 4_0 with CRC scrambled by a MCCH-RNTI or a G-RNTI for broadcast,
[0111] - a CORESET at least associated with a Type0A-PDCCH CSS set on the primary cell of the MCG,
[0112] ○ in some cases, the Type0A-PDCCH CSS set may be configured by searchSpaceOtherSystemInformation in PDCCH-ConfigCommon for a DCI format 1_0 with CRC scrambled by a SI-RNTI,
[0113] - a CORESET at least associated with a Type0B-PDCCH CSS set on the primary cell of the MCG,
[0114] ○ in some cases, the Type0B-PDCCH CSS set may be configured by searchSpaceMCCH and searchSpaceMTCH for a DCI format 4_0 with CRC scrambled by a MCCH-RNTI or a G-RNTI for broadcast,
[0115] - a CORESET at least associated with a Type1-PDCCH CSS set on the primary cell,
[0116] ○ in some cases, the Type1-PDCCH CSS set may be configured by ra-SearchSpace in PDCCH-ConfigCommon for a DCI format with CRC scrambled by a RA-RNTI, a MsgB-RNTI, or a TC-RNTI,
[0117] - a CORESET at least associated with a Type1A-PDCCH CSS set on the primary cell ,
[0118] ○ in some cases, the Type1A-PDCCH CSS set may be configured by sdt-SearchSpace in PDCCH-ConfigCommon for a DCI format with CRC scrambled by a C-RNTI or a CS-RNTI, which may be associated with communication in RRC_INACTIVE state,
[0119] - a CORESET at least associated with a Type2-PDCCH CSS set on the primary cell of the MCG,
[0120] ○ in some cases, the Type2-PDCCH CSS set may be configured by pagingSearchSpace in PDCCH-ConfigCommon for a DCI format 1_0 with CRC scrambled by a P-RNTI,
[0121] - a CORESET at least associated with a Type2A-PDCCH CSS set on the primary cell of the MCG,
[0122] ○ in some cases, the Type2A-PDCCH CSS set may be configured by pei-SearchSpace in pei-ConfigBWP for a DCI format 2_7 with CRC scrambled by a PEI-RNTI, or
[0123] - a CORESET at least associated with a Type3-PDCCH CSS set,
[0124] ○ in some cases, the Type3-PDCCH CSS set may be configured by SearchSpace in PDCCH-Config with searchSpaceType = common for DCI formats with CRC scrambled by INT-RNTI, SFI-RNTI, TPC-PUSCH-RNTI, TPC-PUCCH-RNTI, TPC-SRS-RNTI, or CI-RNTI and, only for the primary cell, C-RNTI, MCS-C-RNTI, CS-RNTI (s) , or PS-RNTI, or
[0125] ○ in some cases, the Type3-PDCCH CSS set may be configured by SearchSpace in pdcch-ConfigMulticast for DCI formats with CRC scrambled by G-RNTI, or G-CS-RNTI, or
[0126] ○ in some cases, the Type3-PDCCH CSS set may be configured by searchSpaceMCCH and searchSpaceMTCH on a secondary cell for a DCI format 4_0 with CRC scrambled by a MCCH-RNTI or a G-RNTI for broadcast.
[0127] In some examples, the common CORESET may be configured by the NW entity to not follow or apply the indicated joint / DL TCI state (s) (e.g., the first joint / DL TCI state or the second joint / DL TCI state) .
[0128] In some examples, the NW entity may configure the UE a UE-specific CORESET, which may be one of the following CORESET: a CORESET only associated with a Type3-PDCCH CSS set on the primary cell, or a USS set on the primary cell or secondary cell. In some cases, the Type3-PDCCH CSS set may be configured by SearchSpace in PDCCH-Config with searchSpaceType = common for DCI formats with CRC scrambled by, C-RNTI, MCS-C-RNTI, CS-RNTI (s) , or PS-RNTI, or in some cases, the USS set may be configured by SearchSpace in PDCCH-Config with searchSpaceType = ue-Specific for DCI formats with CRC scrambled by C-RNTI, MCS-C-RNTI, SP-CSI-RNTI, CS-RNTI (s) , SL-RNTI, SL-CS-RNTI, or SL Semi-Persistent Scheduling V-RNTI.
[0129] In some examples, the UE-specific CORESET may always follow or apply the indicated joint / DL TCI state (s) (e.g., the first joint / DL TCI state or the second joint / DL TCI state) , i.e., no need of further RRC configuration to indicate whether to use / follow / apply.
[0130] FIGs. 5A-5C are diagrams illustrating examples of a PDSCH transmission according to embodiments of the disclosure. The DL beam indication for the PDSCH transmission scheduled by CORESET (s) not applying the indicated TCI may be based on whether the PDSCH transmission is with a scheduling offset larger than or equal to a threshold. The threshold may be reported by the UE via UE capability or configured by the NW entity or pre-defined, e.g., 28 symbols. FIGs. 5A-5C illustrates examples of the DL beam indication for the PDSCH transmission for the above-threshold scenario.
[0131] FIG. 5A is a diagram illustrating an example of a PDSCH transmission, e.g., whether / how to apply indicated joint / DL TCI states for the PDSCH transmission, according to an embodiment. Techniques related to performing a beam indication under the M-TRP scheme and indicating DCI fields in an PDCCH order are discussed, e.g., how to perform a beam indication for the PDSCH scheduled by CORESET (s) not applying indicated TCI is discussed. As an example, at least for an S-DCI M-TRP scheme, when the PDSCH is scheduled by a scheduling CORESET, which does not apply indicated TCI state, e.g., CORESET#0 or a CORESET (at least) associated with CSS, it is challenging to perform the beam indication.
[0132] In some examples, the UE 102 receives 580-1a, 580-2a the scheduled PDSCH transmission using at least one TCI state of the indicated TCI state (s) (e.g., joint / DL TCI state (s) ) based on the configuration of the scheduling DCI in the CORESET indicating the scheduling DCI in the CORESET applies / follows the indicated joint / DL TCI state (s) , then further based on the DCI format; and / or the UE receives 580-3a the scheduled PDSCH transmission via the same quasi-co-location (QCL) assumption or the TCI state (s) (e.g., the second set of TCI states) for receiving the CORESET (e.g., the DCI in the CORESET) scheduling the PDSCH when the CORESET is not configured to follow / apply the indicated joint / DL TCI state (s) .
[0133] Referring to FIG. 5A, the UE 102 receives 540 a MAC-CE activating a first subset of TCI state (s) (e.g., a number of joint / DL TCI state (s) ) from a list of TCI state (s) (e.g., the configured joint / DL TCI state (s) ) . Then, the UE 102 may receive 550 a DCI indicating one or more joint / DL TCI state from the activated joint / DL TCI state (s) . If the MAC-CE only activates one joint / DL TCI state or only indicates two joint / DL TCI state (s) , each of which is associated with different TRP or TRP identifier, the two activated joint / DL TCI states are the first indicated joint / DL TCI state and the second indicated joint / DL TCI state respectively. In such case, receiving the DCI 550 can be skipped.
[0134] Afterwards, the UE 102 receives (e.g., decodes) 560 a DL scheduling DCI, e.g., PDCCH, on a CORESET scheduling the PDSCH transmission. The DL beam determination for the PDSCH may be based on whether the PDSCH transmission is with a scheduling offset larger than or equal to a threshold. The threshold may be reported by the UE via UE capability or configured by the NW entity or pre-defined, e.g., 28 symbols. When the scheduling offset is above the threshold, the PDSCH may be scheduled by a DCI with a DCI format 1_0 or a DCI format 1_1 / 1_2. If the scheduling DCI has the DCI format 1_1 / 1_2, a TCI selection field in the DCI may be used to indicate the one or more joint / DL TCI state from the activated joint / DL TCI state (s) for the DL beam. If the scheduling DCI has a DCI format 1_0, a TCI selection parameter may be used to indicate the one or more joint / DL TCI state for the DL beam. The TCI selection parameter may be an RRC parameter. The UE may receive the TCI selection parameter by an RRC message (not shown) .
[0135] When the scheduling offset is below the threshold, if UE supports more than one default beams, both the first and second indicated TCI states may be used or applied for the DL beam; if UE does not support more than one default beams, the first indicated TCI may be used or applied for the DL beam.
[0136] For CORESET#0 or a CORESET associated with CSS (Common CORESET) , CORESET#0 or a CORESET associated with CSS may not be configured to apply indicated TCI state (s) . In some examples, whether or not to apply indicated TCI state (s) may be the same for CORESET#0 (or a CORESET associated with CSS) and its scheduled PDSCH.
[0137] As illustrated in FIG. 5A, the UE 102 and / or the BS 104 determine (s) 570-1a, 570-2a whether and how to apply the activated or indicated joint / DL TCI state (s) to receive the PDSCH based on a configuration of the scheduling PDCCH. For example, the configuration of the scheduling PDCCH includes whether the scheduling CORESET (i.e., the CORESET with the scheduling PDCCH / DCI) applies / follows the indicated joint / DL TCI state (s) . The UE 102 and / or the BS 104 may determine 570-1a whether and how to apply the activated or indicated joint / DL TCI state (s) to receive the PDSCH based on whether the scheduling CORESET applies / follows the indicated joint / DL TCI state (s) . When the scheduling CORESET applies / follows (or is configured to apply / follow) the indicated joint / DL TCI state (s) , the UE 102 and / or the BS 104 may determine 570-2a how to apply the activated or indicated joint / DL TCI state (s) to receive the PDSCH based on a DCI format such as the DCI format 1_0 or the DCI format 1_1 / 1_2.
[0138] In some examples, the NW entity may configure the RRC parameter for the UE. For example, the RRC parameter is a second RRC parameter (e.g., referring to FIG. 4, the UE may receive 430 the second RRC parameter from the NW entity) . The NW entity may configure the second RRC parameter to indicate TCI selection for the PDSCH scheduled by DCI format 1_0. The second RRC parameter may be the RRC parameter for TCI selection. The second RRC parameter may be applied for the PDSCH scheduled by the DCI with the DCI format 1_0 (e.g., applyIndicatedTCIState-DCI-1-0) . In some examples, the NW entity may use the second RRC parameter to indicate the UE which joint / DL TCI state (s) are applied for receiving PDSCH scheduled by the DCI. Candidate value (s) indicated by the second RRC parameter may be the first joint / DL TCI state, or the second joint / DL TCI state or both the first and the second joint / DL TCI states.
[0139] In some examples, the second RRC parameter may apply or be effective only when the NW entity indicates both the first and the second indicated joint / DL TCI state (e.g., by a TCI field in the DCI in the DCI format 1_1 / 1_2) . If the NW entity only indicates the first indicated joint / DL TCI state or only indicates the second indicated joint / DL TCI state (e.g., by the TCI field) , the UE may apply whichever indicated joint / DL TCI state (i.e., the first or the second indicated joint / DL TCI state) (e.g., by the TCI field) to receive PDSCH scheduled by the DCI with the DCI format 1_0.
[0140] In some examples, the NW entity indicating both the first and the second indicated joint / DL / UL TCI state (e.g., by the TCI field in the DCI format 1_1 / 1_2) may imply or refer to that the UE maintains two active TCI states or maintains the first and the second indicated joint / DL / UL TCI states. As discussed above, the NW entity 104 configures one or more joint / DL / UL TCI states. The NW entity 104 activates a subset of configured joint / DL / UL TCI states. The NW entity 104 may use the TCI field to indicate one or two of the activated joint / DL / UL TCI states. The one or more joint / DL / UL TCI states indicated by the TCI field may be referred to as “the indicated joint / DL / UL TCI state (s) ” . If only one or two configured joint / DL / UL TCI states are activated, transmitting the TCI field can be skipped, then, the one or two activated joint / DL / UL TCI states become “the indicated joint / DL TCI state (s) ” . The indicated joint / DL / UL TCI state (s) include the one or more joint / DL / UL TCI states indicated by the TCI field, or the one or two activated joint / DL / UL TCI states when transmitting the TCI field is skipped. The second RRC message (e.g., referring to FIG. 4, the UE may receive 430 the second RRC parameter from the NW entity) is used to indicate which indicated joint / DL TCI state is applied for the PDSCH transmission scheduled by the DCI format 1_0, because not all of the channels or RSs apply both indicated TCI states. For example, one channel may apply only the first indicated TCI state.
[0141] In some examples, if the NW entity does not configure the second RRC parameter, the UE may apply (only) the first joint / DL TCI states to receive PDSCH scheduled by the DCI with DCI format 1_0. In some other examples, if the NW entity does not configure the second RRC parameter, if the NW entity only indicates the first indicated joint / DL TCI state or only indicates the second indicated joint / DL TCI state (by the TCI field) , the UE may apply whichever indicated joint / DL TCI state (i.e., the first or the second indicated joint / DL TCI state) to receive PDSCH scheduled by the DCI with DCI format 1_0; if the NW entity indicates both the first and the second indicated joint / DL TCI state (by TCI field) , the UE may apply (only) the first joint / DL TCI states to receive PDSCH scheduled by the DCI with DCI format 1_0.
[0142] In some examples, the NW entity may only configure the second RRC parameter in a secondary cell (SCell) . Thus, the second RRC parameter may only be applicable to a SCell. In some other examples, the NW entity may only configure the second RRC parameter in primary cell (PCell) and / or primary secondary cell (PSCell) . Thus, the second RRC parameter may only be applicable to PCell and / or PSCell.
[0143] In some examples, the NW entity may configure a TCI selection field in the DCI with the DCI format 1_1 / 1_2 to indicate TCI selection for the PDSCH scheduled by the DCI with the DCI format 1_1 / 1_2. For example, the TCI selection field is a first DCI field in the DCI with the DCI format 1_1 or 1_2. In some examples, the first DCI field may not be present even the first DCI field is configured. In some examples, the first DCI field may be present only when the NW entity indicates both the first indicated joint / DL TCI state and the second indicated joint / DL TCI state (by TCI field) . If the NW entity only indicates the first indicated joint / DL TCI state or only indicates the second indicated joint / DL TCI state (by TCI field) , the UE may apply whichever indicated joint / DL TCI state (i.e., the first or the second indicated joint / DL TCI state) to receive PDSCH scheduled by the DCI with DCI format 1_1 / 1_2.
[0144] In some examples, the first DCI field may be a field for TCI selection (e.g., TCI selection field) . In some examples, the NW entity may use the first DCI field to indicate the UE which joint / DL TCI state (s) are applied for receiving PDSCH scheduled by the DCI. Candidate value (s) indicated by the first DCI field may be the first joint / DL TCI state, or the second joint / DL TCI state or both the first and the second joint / DL TCI states.
[0145] In some examples, if the NW entity does not configure the first DCI field in the DCI with the DCI format 1_1 or 1_2 or if the first DCI field is not present in the DCI with DCI format 1_1 or 1_2, the UE may apply both the first and the second joint / DL TCI states to receive PDSCH scheduled by the DCI with DCI format 1_1 or 1_2.
[0146] In some examples, if the NW entity does not configure the first DCI field in the DCI with DCI format 1_1 or 1_2 or if the first DCI field is not present in a DCI with DCI format 1_1 or 1_2, when the NW entity only indicates the first indicated joint / DL TCI state or only indicates the second indicated joint / DL TCI state (by the TCI field) , the UE may apply whichever indicated joint / DL TCI state (i.e., the first or the second indicated joint / DL TCI state) to receive PDSCH scheduled by the DCI with DCI format 1_1 or 1_2; when the NW entity indicates both the first and the second indicated joint / DL TCI state (by TCI field) , the UE may apply both the first and the second joint / DL TCI states to receive PDSCH scheduled by the DCI with DCI format 1_1 / 1_2.
[0147] In some examples, the second RRC parameter and / or the first DCI field may only be applicable for PDSCH with the scheduling offset larger than or equal to a threshold. The threshold may be reported by the UE via UE capability or configured by the NW entity or pre-defined, e.g., 28 symbols.
[0148] In some examples, the NW entity may configure the UE a third RRC configuration to indicate TCI selection for CORESET (s) . In some examples, the third RRC configuration may be a RRC configuration for indicating whether a CORESET follows / applies indicated unified TCI state (s) and / or for indicating TCI selection for the CORESET. The third RRC configuration may be applied for CORESET#0, the common CORESET or a UE-specific CORESET. In some examples, the NW entity may use this third RRC configuration to indicate the UE which joint / DL TCI state (s) are applied for receiving a CORESET. In some examples, candidate value (s) indicated by the third RRC configuration to be applied for a UE-specific CORESET may be the first joint / DL TCI state, or the second joint / DL TCI state or both the first and the second joint / DL TCI states. In some examples, candidate value (s) indicated by the third RRC configuration to be applied for CORESET#0 or the common CORESET may be the first joint / DL TCI state, or the second joint / DL TCI state, both the first and the second joint / DL TCI states, or none of the first and the second joint / DL TCI states. The third RRC configuration configured for a CORESET may indicate that the CORESET does not apply any of the indicated joint / DL TCI states. The third RRC configuration may indicate the UE that a CORESET does not apply any of the indicated joint / DL TCI states, by indicating “none of the first and the second joint / DL TCI states” .
[0149] In some examples, if the NW entity does not configure the third RRC configuration for a CORESET, it may imply that the CORESET does not apply any of the indicated joint / DL TCI states.
[0150] In some examples, the third RRC configuration may be configured per-CORESET. In some implementations, the third RRC configuration for at least CORESET#0 or the common CORESET may comprise two RRC parameters, one of which is for indicating whether a CORESET follows / applies indicated unified TCI state (s) and the other is for indicating TCI selection for the CORESET (i.e., first, second, or both) . In some cases, the NW entity may only configure the third RRC configuration for a UE operating in an M-TRP S-DCI mode. In some other cases, the NW entity may configure the third RRC configuration for a UE operating in the M-TRP S-DCI mode or an M-TRP M-DCI mode.
[0151] Still referring to FIG. 5A, in some examples, the UE 102 receives 580-1a, 580-2a the PDSCH transmission using at least one TCI state of the indicated TCI state (s) (e.g., joint / DL TCI state (s) ) based on the configuration of the CORESET indicating / carrying the scheduling DCI uses / applies / follows the indicated TCI state (s) , then further based on the DCI format. In some examples, the TCI selection field or the TCI selection parameter only works when the scheduling DCI in the CORESET applies / follows the indicated TCI state (s) . In some examples, the UE receives 580-1a the scheduled PDSCH via the indicated joint / DL TCI state (s) instructed by the second RRC parameter. The second RRC parameter may be applicable for the PDSCH scheduled by the DCI format 1_0 only when the scheduling DCI in the CORESET for the PDSCH transmission is configured to apply / follow the indicated joint / DL TCI state (s) .
[0152] In some examples, the UE receives 580-3a the scheduled PDSCH transmission via the same QCL assumption or the TCI state (s) (e.g., the second set of TCI states) for receiving the CORESET (e.g., the DCI in the CORESET) scheduling the PDSCH when the CORESET is not configured to follow / apply indicated joint / DL TCI state (s) . If the scheduling CORESET is CORESET#0 or the common CORESET and / or if the scheduling CORESET does not apply / follow the indicated joint / DL TCI state (s) , the UE may not follow or apply the instruction from the second RRC parameter to receive the PDSCH scheduled by DCI format 1_0. In some examples, this may be applicable for the PCell or PSCell. In some examples, this may be applicable for the scheduling PDCCH in one of the search spaces: Type 0 / 0A / 0B / 1 / 1A / 1B / 2 common search space, where the search space type is defined in 3GPP TS 38.213 section 10.1.
[0153] In some examples, the UE receives 580-2a the scheduled PDSCH transmission via the indicated joint / DL TCI state (s) instructed by the first DCI field. The first DCI field may be applicable for the PDSCH transmission scheduled by the DCI format 1_1 / 1_2 only when the scheduling CORESET for the PDSCH is configured to apply / follow indicated joint / DL TCI state (s) . In some examples, if the scheduling CORESET does not apply / follow indicated joint / DL TCI state (s) , the UE may not follow or apply the instruction from the first DCI field to receive the PDSCH scheduled by DCI format 1_1 / 1_2.
[0154] The UE may receive 580-3a the scheduled PDSCH transmission via the same QCL assumption or the TCI state (s) (e.g., the second set of TCI states) for receiving the CORESET (e.g., the DCI in the CORESET) scheduling the PDSCH. In some examples, the UE may apply or use 580-3a the same beam or QCL assumption or reference signal for deriving spatial reception parameter or the same TCI state (s) as that of the scheduling CORESET to receive the PDSCH transmission scheduled by the DCI format 1_0 or the DCI format 1_1 / 1_2 on the scheduling CORESET.
[0155] In some examples, if the scheduling CORESET does not apply / follow indicated joint / DL TCI state (s) , the UE may apply or use 580-3a the same beam or QCL assumption or reference signal for deriving spatial reception parameter or the same TCI state (s) as that of the scheduling CORESET to receive the PDSCH transmission scheduled by the DCI format 1_0 or the DCI format 1_1 / 1_2 on the scheduling CORESET; otherwise, the UE may apply or use 580-1a, 580-2a the indicated joint / DL TCI state (s) (indicated by the first TCI field or the second RRC parameter) for the PDSCH transmission to receive the scheduled PDSCH transmission.
[0156] FIG. 5B is a diagram illustrating another example of a PDSCH transmission according to an embodiment. In some examples, the UE receives 580-1b, 580-2b the PDSCH transmission using at least one TCI state of the indicated joint / DL TCI state (s) based on a TCI selection parameter or a TCI selection field associated with a DCI format when the scheduling CORESET does not apply / follow the indicated TCI state (s) . The TCI selection field or the TCI selection parameter may still work even when the scheduling CORESET does not apply / follow the indicated TCI state (s) .
[0157] Referring to FIG. 5B, the UE 102 receives 540 a MAC-CE activating the first subset of TCI state (s) (e.g., a number of joint / DL TCI state (s) ) from the list of TCI state (s) (e.g., the configured joint / DL TCI state (s) ) . Then, the UE 102 may receive 550 the DCI indicating one or more joint / DL TCI state from the activated joint / DL TCI state (s) . Afterwards, the UE 102 receives (e.g., decodes) 560b a DL scheduling DCI, e.g., PDCCH, on a CORESET scheduling the PDSCH transmission, and the CORESET may be configured to not follow / apply indicated joint / DL TCI state (s) .
[0158] As illustrated in FIG. 5B, the UE 102 and / or the BS 104 determine (s) 570b whether and how to apply the activated or indicated joint / DL TCI state (s) to receive the PDSCH based on a DCI format of the scheduling DCI such as the DCI format 1_0 or the DCI format 1_1 / 1_2.
[0159] In some examples, the UE receives 580-1b the PDSCH transmission via the indicated joint / DL TCI state (s) instructed by the RRC parameter (e.g., the second RRC parameter) for the PDSCH scheduled by the DCI format 1_0, when the scheduling CORESET does not apply / follow the indicated TCI state (s) . The second RRC parameter may still be applicable for the PDSCH scheduled by the DCI format 1_0 even when the scheduling CORESET for the PDSCH does not apply / follow the indicated joint / DL TCI state (s) . In some examples, if the scheduling CORESET does not apply / follow indicated joint / DL TCI state (s) , the UE may still follow or apply 580-1b the instruction from the second RRC parameter to receive the PDSCH scheduled by the DCI format 1_0. In some examples, this may be applicable for the secondary cell (SCell) . In some examples, this may be applicable for the scheduling PDCCH in one of the search spaces: Type 3 common search space or UE specific search space, where the search space type is defined in 3GPP TS 38.213 section 10.1.
[0160] In some examples, the UE receives 580-2b the PDSCH transmission via the indicated joint / DL TCI state (s) instructed by the first DCI field for the PDSCH scheduled by the DCI format 1_1 / 1_2, when the scheduling CORESET does not apply / follow the indicated TCI state (s) . The first DCI field may still be applicable for the PDSCH scheduled by the DCI format 1_1 / 1_2 even when the scheduling CORESET for the does not apply / follow indicated joint / DL TCI state (s) . In some examples, if the scheduling CORESET does not apply / follow the indicated joint / DL TCI state (s) , the UE may still follow or apply 580-2b the instruction from the first DCI field to receive the PDSCH scheduled by the DCI format 1_1 / 1_2.
[0161] FIG. 5C is a diagram illustrating yet another example of a PDSCH transmission according to an embodiment. In some examples, the TCI selection parameter only works when scheduling CORESET applies / follows indicated TCI state (s) , but the TCI selection field still works even when the scheduling CORESET does not apply / follow the indicated TCI state (s) .
[0162] Referring to FIG. 5C, the UE 102 receives 540 a MAC-CE activating the first subset of TCI state (s) (e.g., a number of joint / DL TCI state (s) ) from the list of TCI state (s) (e.g., the configured joint / DL TCI state (s) ) . The UE 102 may receive 550 the DCI indicating one or more joint / DL TCI state from the activated joint / DL TCI state (s) . Afterwards, the UE 102 receives (e.g., decodes) 560 a DL scheduling DCI, e.g., PDCCH, on a CORESET scheduling the PDSCH transmission.
[0163] As illustrated in FIG. 5C, the UE 102 and / or the BS 104 may determine 570-1c whether and how to apply the activated or indicated joint / DL TCI state (s) to receive the PDSCH based on a DCI format of the scheduling DCI (such as the DCI format 1_0 or the DCI format 1_1 / 1_2) . If the DCI format is the DCI format 1_0, the UE 102 and / or the BS 104 may determine 570-2c whether to use or apply the activated or indicated TCI state (s) to receive the PDSCH based on a TCI selection parameter or not using the activated or indicated TCI state (s) based on whether the CORESET is configured to follow / apply the indicated TCI state (s) .
[0164] In some examples, if the PDSCH is scheduled by the DCI format 1_0 on the scheduling CORESET, UE may receive 580-3c the scheduled PDSCH transmission via the same QCL assumption or TCI state (s) (e.g., the second set of TCI states) for receiving the CORESET when the scheduling CORESET for the PDSCH does not apply / follow the indicated joint / DL TCI state (s) ; and the UE may receive 580-2c the scheduled PDSCH transmission via the indicated joint / DL TCI state (s) instructed by the second RRC parameter when the scheduling CORESET for the PDSCH applies / follows the indicated joint / DL TCI state (s) . The second RRC parameter may be not applicable for the PDSCH when the scheduling CORESET for the PDSCH does not apply / follow the indicated joint / DL TCI state (s) if the PDSCH is scheduled by the DCI format 1_0 on the scheduling CORESET. In such cases, the UE may not follow or apply the instruction from the second RRC parameter to receive the PDSCH scheduled by the DCI format 1_0. In such cases, the UE may not follow or apply the instruction from the second RRC parameter to receive the PDSCH scheduled by the DCI format 1_0. In such cases, the UE may apply or use the same beam or QCL assumption or reference signal for deriving spatial reception parameter or the same TCI state (s) as that of the scheduling CORESET to receive the PDSCH.
[0165] In some examples, if the PDSCH is scheduled by the DCI format 1_1 / 1_2 on the scheduling CORESET, the UE receives 580-1c the scheduled PDSCH transmission via the indicated joint / DL TCI state (s) instructed by the first DCI field. When the PDSCH is scheduled by the DCI format 1_1 / 1_2 on the scheduling CORESET, the first DCI field may be still applicable for the PDSCH even if the scheduling CORESET for the PDSCH does not apply / follow the indicated joint / DL TCI state (s) . In such cases, the UE may still follow or apply the instruction from the first DCI field to receive the PDSCH scheduled by DCI format 1_1 / 1_2. In some cases, this may be applicable for the PCell or PSCell. In some cases, this may be applicable for the scheduling PDCCH in one of the search spaces: Type 0 / 0A / 0B / 1 / 1A / 1B / 2 common search space, where the search space type is defined in 3GPP TS 38.213 section 10.1.
[0166] In some examples, the UE 102 and / or the BS 104 determine (s) whether and how to apply the activated or indicated joint / DL TCI state (s) to receive the PDSCH transmission based the UE capability (or RRC configuration) to the techniques as described in connection with FIGs. 5A-5C.
[0167] In some examples, the NW entity may configure whether the PDSCH transmission, scheduled by the CORESET not applying / following indicated joint / DL TCI state (s) , should follow / apply indicated joint / DL TCI state (s) . If the NW entity configures that the PDSCH transmission should apply / follow indicated joint / DL TCI state (s) , regardless of whether its scheduling CORESET applies / follows indicated joint / DL TCI state (s) , the UE may apply one of the first, the second or both of the first and the second indicated joint / DL TCI state (s) to receive the PDSCH transmission. If the NW entity configures that the PDSCH transmission should apply / follow indicated joint / DL TCI state (s) , regardless of whether its scheduling CORESET applies / follows indicated joint / DL TCI state (s) , the second RRC parameter and / or the first DCI field (if configured) is applicable for indicating whether to use the first, the second or both of the first and the second indicated joint / DL TCI state (s) to receive the PDSCH.
[0168] In some examples, the NW entity may configure whether the PDSCH transmission scheduled by the CORESET not applying / following indicated joint / DL TCI state (s) should follow / apply indicated joint / DL TCI state (s) , based on the UE capability. The UE may indicate that whether the UE supports that the PDSCH transmission scheduled by the CORESET not applying / following indicated joint / DL TCI state (s) can follow / apply the indicated joint / DL TCI state (s) .
[0169] In addition to scenarios discussed as in FIGs. 5A-5C, there are some other scenarios. In some examples, before the UE decodes the PDCCH scheduling the PDSCH transmission successfully in a slot, the UE may (attempt to) buffer or receive (potential) the PDSCH transmission via one or more default beams or the joint / DL TCI state (s) . In some examples, the one or more default beams or the joint / DL TCI state (s) used by the UE to buffer / receive PDSCH transmission may not be the same as that indicated by the second RRC parameter or the first DCI field.
[0170] In some examples, the UE may report a first UE capability to indicate one of the following: for the M-TRP M-DCI mode or S-DCI mode, whether the UE supports two default beams or receiving beams for buffering / receiving PDSCH before the UE decodes successfully the scheduling PDCCH of the PDSCH, or for M-TRP M-DCI mode or S-DCI mode, whether the UE supports two default beams or receiving beams for receiving a PDSCH, where the scheduling offset between the scheduling PDCCH and the PDSCH is below a threshold, or for M-TRP M-DCI mode or S-DCI mode, whether the UE supports more than one default beam or receiving beam for buffering / receiving PDSCH before the UE decodes successfully the scheduling PDCCH of the PDSCH, or for M-TRP M-DCI mode or S-DCI mode, whether the UE supports more than one default beam or receiving beam for receiving a PDSCH, where the scheduling offset between the scheduling PDCCH and the PDSCH is below a threshold.
[0171] In some examples, the UE may apply the indicated TCI state, regardless of configuration of whether to apply indicated TCI state (s) . In some examples, if the UE indicates, via the first UE capability, that the UE supports two or more than one default beams for buffering / receiving PDSCH, the UE may use the first and the second indicated joint / DL TCI states for buffering / receiving PDSCH in a slot before the UE decodes successfully the scheduling PDCCH of the PDSCH, if the NW entity indicates the first and the second indicated joint / DL TCI states. The UE may perform such behavior regardless of whether the UE is configured to monitor a CORESET not applying / following indicated joint / DL TCI state (s) in the slot.
[0172] In some examples, if the UE indicates, via the first UE capability, that the UE does not support two or more than one default beams for buffering / receiving PDSCH, the UE may use (only) the first indicated joint / DL TCI states for buffering / receiving PDSCH in a slot before the UE decodes successfully the scheduling PDCCH of the PDSCH, if the NW entity indicates the first and the second indicated joint / DL TCI states. The UE may perform such behavior regardless of whether the UE is configured to monitor a CORESET not applying / following indicated joint / DL TCI state (s) in the slot.
[0173] In some examples, if the NW entity only indicates one joint / DL TCI state (e.g., only the first or only the second indicated joint / DL TCI state) , the UE may use the indicated joint / DL TCI state (the first or the second indicated joint / DL TCI state) for buffering / receiving PDSCH before the UE decodes successfully the scheduling PDCCH of the PDSCH in a slot, regardless of whether the UE supports two or more than one default beams for buffering / receiving PDSCH.
[0174] In some examples, the UE may consider the DL beam of CORESET (s) not applying indicated TCI state (s) when determining how to buffer / receive PDSCH. If the UE indicates, via the first UE capability, that the UE supports two or more than one default beams for buffering / receiving PDSCH, when the UE is configured to monitor a CORESET not applying / following indicated joint / DL TCI state (s) in the slot, the UE may use a third beam and one of the first or the second indicated joint / DL TCI states for buffering / receiving PDSCH in a slot before the UE decodes successfully the scheduling PDCCH of the PDSCH, where the NW entity indicates the first and the second indicated joint / DL TCI states. If there is a CORESET not applying indicated TCI state (s) , the UE may use the DL beam of the CORESET and one of the first or second indicated TCI state (s) . Otherwise, the UE may use both the first and second indicated TCI state (s) .
[0175] In some examples, the third beam may be a DL beam or QCL assumption or a reference signal for deriving spatial reception parameters or a TCI state for receiving the CORESET not applying / following indicated joint / DL TCI state (s) . In some examples, if the UE is configured to monitor more than one CORESET (s) not applying / following indicated joint / DL TCI state (s) in the slot, the third beam may be a DL beam or QCL assumption or a reference signal for deriving spatial reception parameters or a TCI state for receiving the CORESET with lowest CORESET index among the more than one CORESET (s) . If the UE is not configured to monitor a CORESET not applying / following indicated joint / DL TCI state (s) in the slot (or there is no such CORESET) , the UE may use the first and the second indicated joint / DL TCI states for buffering / receiving PDSCH in the slot before the UE decodes successfully the scheduling PDCCH of the PDSCH, where the NW entity indicates the first and the second indicated joint / DL TCI states.
[0176] In some examples, if the UE indicates, via the first UE capability, that the UE does not support two or more than one default beams for buffering / receiving PDSCH, If there is a CORESET not applying indicated TCI state (s) , the UE may use the DL beam of the CORESET. Otherwise, the UE may use the first indicated TCI state. If the UE is configured to monitor a CORESET not applying / following indicated joint / DL TCI state (s) in the slot, the UE may use a third beam for buffering / receiving PDSCH in a slot before the UE decodes successfully the scheduling PDCCH of the PDSCH. In some cases, the third beam may be a DL beam or QCL assumption or a reference signal for deriving spatial reception parameters or a TCI state for receiving the CORESET not applying / following indicated joint / DL TCI state (s) . In some cases, if the UE is configured to monitor more than one CORESET (s) not applying / following indicated joint / DL TCI state (s) in the slot, the third beam may be a DL beam or QCL assumption or a reference signal for deriving spatial reception parameters or a TCI state for receiving the CORESET with lowest CORESET index among the more than one CORESET (s) ,
[0177] If the UE is not configured to monitor a CORESET not applying / following indicated joint / DL TCI state (s) in the slot (or there is no such CORESET) , when the NW entity indicates the first and the second indicated joint / DL TCI states, the UE may use the first indicated joint / DL TCI states for buffering / receiving PDSCH in the slot before the UE decodes successfully the scheduling PDCCH of the PDSCH; alternatively, the UE may use the second indicated joint / DL TCI states in this case.
[0178] If the UE is not configured to monitor a CORESET not applying / following indicated joint / DL TCI state (s) in the slot (or there is no such CORESET) , when the NW entity only indicates one joint / DL TCI state (the first or the second indicated joint / DL TCI state) , the UE may use the indicated joint / DL TCI state (the first or the second indicated joint / DL TCI state) for buffering / receiving PDSCH before the UE decodes successfully the scheduling PDCCH of the PDSCH in the slot.
[0179] FIG. 6 is a signaling diagram 600 illustrating communications between a UE 102 and a network entity 104 for a UE-initiated beam selection according to an embodiment. UE-initiated beam selection / switching or update may be supported, e.g., in 5G NR, which allows UE to report a recommended reference signal or unified TCI state. The recommended reference signal or the unified TCI state may correspondingly become the serving beam or serving TCI state for communication between the UE 102 and the NW entity 104. In some implementations, the NW entity 104 may send further confirmation to confirm the recommended reference signal or unified TCI state. In this way, the latency in the beam switching is reduced, and the potential beam failure may be avoided. However, the set of UL / DL channel (s) or RS(s) applying the UE-suggested beams may not be the same as those applying the unified TCI states indicated by the NW entity 104. Therefore, it is challenging to determine how to perform the UE-initiated beam switching, which UL / DL channels or RSs can apply or follow the UE-selected beam (s) (e.g., the UE-suggested beam (s) ) or the TCI state (s) , whether the NW entity sends feedback, and timeline issues.
[0180] Referring to FIG. 6, the UE 102 may transmit or report 610 a UE capability for supporting a UE-initiated beam selection / switching. The UE 102 may transmit 610, to the network entity, a UE capability report indicating the UE capability for supporting an M-TRP scheme based on the UE-initiated beam selection. The NW entity 104 may receive 610, from the UE, the UE capability report indicating the UE capability for supporting the M-TRP scheme based on the UE-initiated beam selection.
[0181] The NW entity 104 transmits 620, to the UE, a first control signal (e.g., an RRC signal including an RRC configuration) configuring a UE-initiated beam selection. The UE 102 receives 620, from the network entity, the first control signal (e.g., an RRC signal including an RRC configuration) configuring the UE-initiated beam selection. The NW entity 104 may configure 620 the UE-initiated beam selection / switching to the UE, based on the UE capability.
[0182] The NW entity 104 may then transmit 630 a second control signal for configuring / indicating whether a channel or RS applies / follows the UE-selected (e.g., UE suggested, UE preferred or qualified) beam (s) from the UE-initiated beam selection / switching. The UE 102 may then receive 630 the second control signal for configuring / indicating whether the channel or RS applies / follows the UE-selected (e.g., UE suggested, UE preferred or qualified) beam (s) from the UE-initiated beam selection / switching. The second control signal may indicate which DL / UL channel (s) or RS (s) is / are applicable for applying the one or more UE-selected (e.g., UE preferred or qualified) beams. The second control signal may be a RRC parameter, a MAC-CE or a DCI. In some examples, the second control signal may be common for all DL and / or UL channel (s) or RS (s) .
[0183] In some examples, the second control signal may be specific to a DL channel / RS or a UL channel / RS. For example, the NW entity may configure a first second control signal for PDCCH, a second second control signal for PUCCH, a third second control signal for AP CSI-RS, a fourth second control signal for SRS, and possibly more such second control signals for other channel (s) and RS (s) . If the second control signal is an RRC signal, whether a channel or RS could apply the one or more UE-selected beams may be configured per channel, per RS, per channel group, or per RS set.
[0184] In some examples, the UE 102 transmits 640, to the network entity, a report indicating one or more UE-selected beams (e.g., UE suggested, UE preferred or qualified beams) based on the first control signal. The NW entity 104 receives 640, from the UE, the report indicating the one or more UE-selected beams based on the first control signal. If the NW entity configures 620 the UE-initiated beam selection / switching to the UE, the UE may indicate 640 the one or more UE-selected beams (e.g., UE suggested, UE preferred or qualified beams) in the report. The indicated one or more UE-selected beams (e.g., UE suggested, UE preferred or qualified beams) may be one single beam, or may be at least two beams, each of which is associated with a different TRP or TRP identifier. The UE may report one or more beams for the M-TRP operation. The UE may report one or more additional beams to update the beam for a channel / RS that does not follow / apply the indicated joint / DL / UL TCI state (i.e., NW indicated beam) . UE may report the beams for channels or RSs following / applying indicated joint / DL / UL TCI states and the other beams for channels or RSs not following / applying indicated TCI states by a single report or separate report.
[0185] In some examples, the UE 102 may also suggest which channel / RS could apply the one or more UE-selected beams (e.g., UE suggested, UE preferred or qualified beams) when reporting the one or more UE-selected beams. The report may further indicate the at least one of the channel or the reference signal to use the one or more UE-selected beams.
[0186] In response to the report, the NW entity 104 may feedback or transmit 650 a confirmation message to confirm the one or more UE-selected beams (e.g., UE suggested, UE preferred or qualified beams) indicated by the UE can apply. The UE 102 may receive 650 the confirmation message to confirm the one or more UE-selected beams (e.g., UE suggested, UE preferred or qualified beams) indicated by the UE can apply.
[0187] The UE 102 and / or the NW entity 104 may determine 670 whether to apply the one or more UE-selected beams (e.g., UE suggested, UE preferred or qualified beams) from the UE-initiated beam selection / switching to receive a channel or RS based on the second control signal. The UE 102 communicates 680 with the NW entity 104 using the one or more UE-selected beams for at least one of a channel or a reference signal for the M-TRP scheme. The NW entity 104 communicates 680 with the UE 102 using the one or more UE-selected beams for at least one of a channel or a reference signal for the M-TRP scheme. For example, the NW entity 104 transmits 680 a channel or RS indicated by the second control signal using / applying the one or more UE-selected beams, and the UE 102 receives 680 the channel or RS indicated by the second control signal using / applying the one or more UE-selected beams. Upon the transmission of the report or the reception of the confirmation message, the UE may apply the one or more UE-selected beams (e.g., UE suggested, UE preferred or qualified beams) in the report for a subset or all of DL / UL channel (s) or RS (s) . Upon the transmission of the report or the reception of the confirmation message, the UE may apply the one or more UE-selected beams (e.g., UE suggested, UE preferred or qualified beams) in the report, and not apply the previously applied joint / DL / UL TCI state indicated by the NW entity or previously applied one or more UE-selected beams (e.g., UE suggested, UE preferred or qualified beams) in a last report. Channels or RSs following / applying one or more UE-selected beams may not be able to follow / apply the NW-indicated beam, vice versa
[0188] In some examples, the one or more UE-selected (e.g., UE preferred or qualified) beams in the report may be in form of a reference signal or deriving spatial transmission or reception parameters. In some other examples, the one or more UE-selected (e.g., UE preferred or qualified) beams in the report may be in form of one or more joint / DL / UL TCI state (s) . In some cases, the amount of reported joint / DL / UL TCI state (s) may depend on whether a joint or separate TCI state mode is configured and / or whether an S-TRP or an M-TRP operation is configured.
[0189] In some examples, a channel or RS that can apply or follow the joint / DL / UL TCI state indicated by the NW entity may not be able to apply / follow the one or more UE-selected (e.g., UE preferred or qualified) beams in the report. A channel or RS that cannot apply or follow the joint / DL / UL TCI state indicated by the NW entity may be able to apply / follow the one or more UE-selected (e.g., UE preferred or qualified) beams in the report. For example, a CORESET#0 which is configured to apply / follow indicated joint / DL TCI state (s) may not be able to apply / follow the one or more UE-selected (e.g., UE preferred or qualified) beams in the report. For another example, a periodic CSI-RS which is configured to not apply / follow indicated joint / DL TCI state (s) may be able to apply / follow the one or more UE-selected (e.g., UE preferred or qualified) beams in the report.
[0190] In some examples, the NW entity may configure the UE to report more than one (e.g., two) UE-selected (e.g., UE preferred or qualified) beams for the M-TRP operation, where each beam corresponds to one TRP or is associated with a TRP identifier. In one example, the first reported beam updates the first indicated joint / DL / UL TCI state and the second reported beam updates the second indicated joint / DL / UL TCI state. Thus, the UE applies the first reported beam for the channels / RSs applying the first indicated joint / DL / UL TCI state and the UE applies the second reported beam for the channels / RSs applying the second indicated joint / DL / UL TCI state. In some other examples, the UE may report one or more additional beams to update the beam for a channel / RS that does not follow / apply the indicated joint / DL / UL TCI state. The UE may report the beams to update the beam for channels / RSs following or applying indicated joint / DL / UL TCI states and the beams to update the beam for channels / RSs not following / applying indicated TCI states by a single report or separate report.
[0191] FIG. 7 is signaling diagram 700 illustrating communications between a UE 102 and a network entity 104 for interpreting a PDCCH order according to an embodiment. For inter-cell M-TRP 2TA, a new DCI field (e.g., a first field or a second DCI field) is introduced in PDCCH order to indicate which PRACH configuration to use for triggered a contention free random access (CFRA) . The new DCI field (e.g., a first field or a second DCI field) may indicate a PRACH configuration for a serving cell or a PRACH configuration for a candidate cell (e.g., a neighboring cell, a PRACH configuration associated with an additional PCI) . For LTM (L1 / L2 triggered mobility) , a new DCI field (e.g., a second filed or a third DCI field) is introduced in the PDCCH order to indicate which candidate cell for which the triggered CFRA is intended. The new DCI field (e.g., a second filed or a third DCI field) may indicate a serving cell or one of configured candidate cell. It is challenging to interpret the two new DCI fields when both present in the PDCCH order.
[0192] In some examples, if the NW entity configures the UE inter-cell M-TRP 2TA, the NW entity may configure the UE one or more PRACH configurations associated with one or more configured additional PCIs. In some cases, each of the one or more PRACH configurations is associated with each of the one or more configured additional PCIs, i.e., one-to-one mapping.
[0193] In some examples, the NW entity may configure the second DCI field in the PDCCH order for triggering CFRA. In some cases, the second DCI field may indicate whether the PDCCH order is triggering CFRA for serving cell or neighboring cell. In some cases, the second DCI field may indicate whether the PDCCH order is associated with the serving cell PCI or the neighboring cell PCI. In some cases, the second DCI field may indicate whether the PDCCH order is triggering CFRA for TAG associated with the serving cell PCI or neighboring cell PCI. In some cases, the second DCI field may indicate whether to apply PRACH configuration associated with the serving cell PCI or that associated with additional PCI in CFRA triggered by the PDCCH order. The second DCI field may be a one-bit field, where one candidate value may indicate the PRACH configuration associated with the serving cell PCI and the other one may indicate that associated with additional PCI. The second DCI field may be a PRACH configuration indication field.
[0194] In some examples, the NW entity may configure the UE to perform LTM. In some cases, the NW entity may further configure the UE to acquire TA value, preferably via RA procedure, before the UE receives a CSC (or early TA acquisition) . If the NW entity configures the UE to acquire TA value before the UE receives a CSC (or early TA acquisition) , the NW entity may configure a third DCI field in a PDCCH order for triggering CFRA. In some cases, the third DCI field may indicate whether the PDCCH order is triggered for the serving cell or a LTM candidate cell. In some cases, the bit-width of the third DCI field may be related to the number of LTM candidate cells with early TA acquisition. In some cases, the bit-width of the third DCI field may be determined based on log (C+1) , where C is the number of LTM candidate cells configured / enabled with early TA acquisition. In some cases, one codepoint of the third DCI field is to indicate serving cell, e.g., the lowest codepoint ( “0” or “00” or “000” ) , or the highest codepoint. The third DCI field may be a cell indicator field.
[0195] Referring to FIG. 7, a UE 102 receives 720, from a network entity104, a control signal including a first field or a second field different from the first field in a PDCCH order. The network entity 104 transmits 720, to the UE 102, the control signal including the first field or the second field different from the first field in the PDCCH order. In some examples, the first field indicates that the PDCCH order is for triggering a CFRA for a serving cell or a neighboring cell. In some examples, the first field indicates that the PDCCH order is for triggering the CFRA for the serving cell or a candidate cell. The second field indicates that the PDCCH order is for triggering an LTM procedure for the serving cell or a candidate cell. The UE and / or BS may determine 770 how to interpret the PDCCH order. The UE 102 communicates 780 with the network entity 104 based on at least one of the first field (e.g., the second DCI field) or the second field (e.g., the third DCI field) of the control signal. The network entity 104 communicates 780 with the UE 102 based on at least one of the first field (e.g., the second DCI field) or the second field (e.g., the third DCI field) of the control signal.
[0196] In some examples, the first field (e.g., the second DCI field or the PRACH configuration field) only applies when the second field or the third DCI field (e.g., cell indicator field) indicates a serving cell. In some examples, if both the second DCI field and the third DCI field are configured or present in the PDCCH order, the UE only processes or applies the second DCI field when the third DCI field indicates serving cell, or the UE only processes or applies the second DCI field when the third DCI field indicates the PDCCH order is for serving cell, or the UE only processes or applies the second DCI field when the third DCI field indicates the lowest (or alternatively the highest) codepoint.
[0197] For example, if the third DCI field indicates the serving cell, the UE may apply the PRACH configuration associated with serving cell PCI or additional PCI according to instruction from the second DCI field.
[0198] In some examples, the second field (e.g., the third DCI field or the cell indicator field) only applies when the first field (e.g., the second DCI field or the PRACH configuration field) indicates a serving cell PRACH configuration. In some examples, if both the second DCI field and the third DCI field are configured or present in the PDCCH order, the UE only processes or applies the third DCI field when the second DCI field indicates the PDCCH order is associated with serving cell, or the UE only processes or applies the third DCI field when the second DCI field indicates the UE to apply PRACH configuration associated with serving cell or serving PCI for RA procedure triggered by the PDCCH order, or the UE only processes or applies the third DCI field when the second DCI field indicates the lowest (or alternatively the highest) codepoint.
[0199] For example, if the second DCI field indicates the PDCCH order is associated with serving cell, the UE may apply trigger RA procedure for the serving cell or a LTM candidate cell according to instruction from the third DCI field.
[0200] In some examples, a third DCI field (e.g., a fourth DCI field) in the PDCCH order is introduced to indicate whether to apply the first DCI field or the second field. If both the second DCI field and the third DCI field are configured or present in the PDCCH order, or if the NW entity configures inter-cell M-TRP 2TA and LTM simultaneously, the fourth DCI field may be configured by the NW entity or present in the PDCCH order. In some cases, the fourth DCI field may indicate whether to apply the second DCI field or the third DCI field in the PDCCH order. In some cases, the fourth DCI field may indicate whether the PDCCH order is associated with inter-cell M-TRP 2TA or LTM.
[0201] In some examples, the second DCI field and the third DCI field may be one DCI field. In some cases, how to interpret the one DCI field may be dependent on the fourth DCI field. The bit-width of the one DCI field may be determined based on max (1, log (C+1) ) , where C is the number of LTM candidate cells with early TA acquisition.
[0202] In some examples, if the fourth DCI field indicates the PDCCH order is associated with inter-cell M-TRP 2TA, the UE may only use one bit of the one DCI field, and the remaining bits, if any, are reserved, and / or the UE may use one bit of the one DCI field to determine whether to apply PRACH configuration associated with serving cell PCI or that associated with additional PCI in CFRA triggered by the PDCCH order.
[0203] In some examples, if the fourth DCI field indicates the PDCCH order is associated with LTM, the UE may use the one DCI field to determine whether the PDCCH order is triggered for serving cell or a LTM candidate cell. In some examples, the fourth DCI field may be one bit in the one DCI field.
[0204] In some examples, the DCI second field (PRACH configuration field) and the third DCI field (cell indicator field) indications are not allowed to be present together, e.g., the inter-cell 2TA and the early TA acquisition for LTM cannot be configured together.
[0205] In some examples, the NW entity may refrain from configuring the inter-cell M-TRP 2TA and LTM to the UE simultaneously. In some cases, the NW entity may refrain from configuring the second DCI field and the third DCI field in the PDCCH order simultaneously. In some cases, the NW entity may still be allowed to configure the intra-cell M-TRP 2TA and LTM to the UE simultaneously. Alternatively, the NW entity may refrain from configuring intra-cell M-TRP 2TA (or M-TRP 2TA) and LTM to the UE simultaneously.
[0206] In some examples, for a serving cell configured with LTM, the NW entity may refrain from configuring more than one timing advance groups (TAGs) for the serving cell or a serving cell groups that contains the serving cell. Alternatively, for a serving cell group with more than one TAGs configured, the NW entity may refrain from configuring LTM for any serving cell within the serving cell group. Alternatively, for a serving cell with more than one TAGs configured, the NW entity may refrain from configuring LTM for the serving cell.
[0207] In some other examples, for a serving cell configured with LTM, the NW entity may refrain from configuring both additional PCIs and more than one TAGs for the serving cell or a serving cell groups that contains the serving cell. The NW entity may be allowed to configure only one of additional PCIs or more than one TAGs for the serving cell or a serving cell groups that contains the serving cell. Alternatively, for a serving cell group with additional PCIs and more than one TAGs configured, the NW entity may refrain from configuring LTM for any serving cell within the serving cell group. Alternatively, for a serving cell with additional PCIs and more than one TAGs configured, the NW entity may refrain from configuring LTM for the serving cell.
[0208] In some examples, the UE may not expect to receive configuration (s) of inter-cell M-TRP 2TA and LTM simultaneously. In some cases, the UE may not expect that the second DCI field and the third DCI field are present in a PDCCH order simultaneously.
[0209] In some examples, if the UE receives configuration (s) of inter-cell M-TRP 2TA and LTM simultaneously or if both the second DCI field and the third DCI field are present in a PDCCH order, the UE may discard or may not use or process the configuration (s) , or the UE may consider or determines it is error case or error configuration, or the UE may perform RRC reconfiguration, or the UE may discard or may not use or process the second DCI field and / or the third DCI field.
[0210] FIGs. 4 and 5A-5C illustrate the examples of the PDSCH transmission. FIG. 6 illustrates the example of the UE-initiated beam selection. FIG. 7 illustrates the example of interpreting the PDCCH order. FIGs. 8-13 show methods for implementing one or more aspects of FIGs. 4-7. In particular, FIGs. 8, 10 and 12 show implementations by the UE 102 of the one or more aspects of FIGs. 4-7. FIG. 9, 11 and 13 show implementations by the network entity 104 of the one or more aspects of FIGs. 4-7.
[0211] FIG. 8 illustrates a flowchart 800 of a method of wireless communication at a UE for a PDSCH transmission according to an embodiment. With reference to FIGs. 1-5C, the method may be performed by the UE 102. In embodiments, the UE 102 may transmit 810, to a network entity 104, a UE capability report indicating a UE capability of the UE 102 for supporting an M-TRP scheme. For example, referring to FIG. 4, the UE 102 may transmit or report 410 UE capability (s) for supporting unified TCI states for the M-TRP scheme.
[0212] The UE 102 receives 840, from the network entity 104, a first control signal indicating a first set of TCI states. For example, referring to FIG. 4, the UE 102 receives 440 the MAC-CE activating a subset of joint / DL TCI state (s) from the list of joint / DL TCI state (s) . The UE 102 may receive 450 the DCI indicating the one or more joint / DL TCI state (s) from the activated joint / DL TCI state (s) . If the MAC-CE only activates one joint / DL TCI state or only indicates two joint / DL TCI state (s) , each of which is associated with different TRP or TRP identifier, the two activated joint / DL TCI states are the first indicated joint / DL TCI state and the second indicated joint / DL TCI state respectively. In such case, transmitting the DCI 450 can be skipped. The first set of TCI states may include the activated subset of joint / DL TCI state (s) from the list of joint / DL TCI state (s) (e.g., by the MAC-CE) or the indicated one or more joint / DL TCI state (s) from the activated joint / DL TCI state (s) (e.g., by the DCI) . The first control signal may include the MAC-CE which activates the subset of joint / DL TCI state (s) from the list of joint / DL TCI state (s) or the DCI which indicates the one or more joint / DL TCI state (s) from the activated joint / DL TCI state (s) .
[0213] The UE 102 receives 860, from the network entity 104, a second control signal scheduling a PDSCH transmission for the M-TRP scheme. The second control signal is associated with a second set of TCI states. For example, referring to FIG. 4, the UE 102 receives 460 the PDCCH transmission in the CORESET scheduling the PDSCH transmission. The one or more TCI states for receiving the PDCCH transmission (e.g., DCI) in the scheduling CORESET may be referred as a second set of TCI states. The second set of TCI states is for receiving the scheduling CORESET (e.g., the PDCCH transmission or the DCI) .
[0214] The UE 102 receives 880, from the network entity 104, the PDSCH transmission using at least one TCI state of the first set of TCI states or using the second set of TCI states based on a configuration of the second control signal. For example, referring to FIG. 4, the UE 102 receives 480 the PDSCH transmission scheduled by the PDCCH in the CORESET based on the configuration of the scheduling PDCCH transmission. FIG. 8 describes a method from a UE-side of a wireless communication link, whereas FIG. 9 describes a method from a network-side of the wireless communication link.
[0215] FIG. 9 is a flowchart 900 of a method of wireless communication at a network entity. With reference to FIGs. 1-5C, the method may be performed by one or more network entities 104, which may correspond to a base station or a unit of the base station, such as the RU 106, the DU 108, and / or the CU 110. In embodiments, the network entity 104 may receive 910, from a UE 102, a UE capability report indicating a UE capability of the UE 102 for supporting an M-TRP scheme. For example, referring to FIG. 4, the network entity 104 may receive 410 the UE capability (s) for supporting the unified TCI states for the M-TRP scheme.
[0216] The network entity 104 transmits 940, to the UE102, a first control signal indicating a first set of TCI states. For example, referring to FIG. 4, the network entity 104 transmits 440 an MAC-CE) activating a subset of joint / DL TCI state (s) (e.g., a number of joint / DL TCI state (s) ) from the list of joint / DL TCI state (s) (e.g., the configured joint / DL TCI state (s) ) . The network entity 104 may transmit 450 a DCI indicating one or more joint / DL TCI state (s) from the activated joint / DL TCI state (s) . If the MAC-CE only activates one joint / DL TCI state or only indicates two joint / DL TCI state (s) , each of which is associated with different TRP or TRP identifier, the two activated joint / DL TCI states are the first indicated joint / DL TCI state and the second indicated joint / DL TCI state respectively. In such case, transmitting the DCI 450 can be skipped. The first set of TCI states may include the activated subset of joint / DL TCI state (s) from the list of joint / DL TCI state (s) (e.g., by the MAC-CE) or the indicated one or more joint / DL TCI state (s) from the activated joint / DL TCI state (s) (e.g., by the DCI) . The first control signal may include the MAC-CE which activates the subset of joint / DL TCI state (s) from the list of joint / DL TCI state (s) or the DCI which indicates the one or more joint / DL TCI state (s) from the activated joint / DL TCI state (s) .
[0217] The network entity 104 transmits 960, to the UE102, a second control signal scheduling a PDSCH transmission for the M-TRP scheme. The second control signal is associated with a second set of TCI states. For example, referring to FIG. 4, the network entity 104 transmits 460 a PDCCH transmission in a CORESET scheduling the PDSCH transmission. The one or more TCI states for receiving the PDCCH transmission (e.g., DCI) in the scheduling CORESET may be referred as a second set of TCI states. The second set of TCI states is for receiving the scheduling CORESET (e.g., the PDCCH transmission or the DCI) .
[0218] The network entity 104 transmits 980, to the UE102, the PDSCH transmission using at least one TCI state of the first set of TCI states or using the second set of TCI states based on a configuration of the second control signal. For example, referring to FIG. 4, t the network entity 104 transmits 480 the PDSCH transmission scheduled by the PDCCH in the CORESET based on the configuration of the scheduling PDCCH transmission.
[0219] FIG. 10 illustrates a flowchart 1000 of a method of wireless communication at a UE for a UE-initiated beam selection according to an embodiment. With reference to FIGs. 1-3B and 6, the method may be performed by the UE 102. In embodiments, the UE 102 may transmit 1010, to a network entity 104, a UE capability report indicating a UE capability of the UE 102 for supporting an M-TRP scheme based on a UE-initiated beam selection. For example, referring to FIG. 6, the UE 102 may transmit 610, to the network entity, a UE capability report indicating the UE capability for supporting an M-TRP scheme based on the UE-initiated beam selection.
[0220] The UE 102 receives 1020, from the network entity 104, a first control signal configuring a UE-initiated beam selection for a multiple transmission-reception point (M-TRP) scheme. For example, referring to FIG. 6, the UE 102 receives 620, from the network entity, the first control signal (e.g., an RRC signal including an RRC configuration) configuring the UE-initiated beam selection.
[0221] The UE 102 may receive 1030, from the network entity, a second control signal indicating the at least one of the channel or the reference signal to use the one or more UE-selected beams. For example, referring to FIG. 6, the UE 102 may then receive 630 the second control signal for configuring / indicating whether the channel or RS applies / follows the UE-selected (e.g., UE suggested, UE preferred or qualified) beam (s) from the UE-initiated beam selection / switching.
[0222] The UE 102 transmits 1040, to the network entity (104) , a report indicating one or more UE-selected beams based on the first control signal. For example, referring to FIG. 6, the UE 102 transmits 640, to the network entity, a report indicating one or more UE-selected beams (e.g., UE suggested, UE preferred or qualified beams) based on the first control signal. The NW entity 104 receives 640, from the UE, the report indicating the one or more UE-selected beams based on the first control signal.
[0223] The UE 102 may receive 1050, from the network entity 104, a confirmation message to confirm the one or more UE-selected beams. For example, referring to FIG. 6, the UE 102 may receive 650 the confirmation message to confirm or approve the one or more UE-selected beams (e.g., UE suggested, UE preferred or qualified beams) indicated by the UE can apply.
[0224] The UE 102 communicates 1080 with the network entity 104, using the one or more UE-selected beams for at least one of a channel or a reference signal for the M-TRP scheme. For example, referring to FIG. 6, the UE 102 communicates 680 with the NW entity 104 using the one or more UE-selected beams for at least one of a channel or a reference signal for the M-TRP scheme. FIG. 10 describes a method from a UE-side of a wireless communication link, whereas FIG. 11 describes a method from a network-side of the wireless communication link.
[0225] FIG. 11 is a flowchart 1100 of a method of wireless communication at a network for a UE-initiated beam selection according to an embodiment. With reference to FIGs. 1-3B and 6, the method may be performed by one or more network entities 104, which may correspond to a base station or a unit of the base station, such as the RU 106, the DU 108, and / or the CU 110. In embodiments, the network entity 104 may receive 1110, from a UE 102, a UE capability report indicating a UE capability of the UE 102 for supporting an M-TRP scheme based on a UE-initiated beam selection. For example, referring to FIG. 6, the UE 102 may transmit 610, to the network entity, a UE capability report indicating the UE capability for supporting an M-TRP scheme based on the UE-initiated beam selection.
[0226] The network entity 104 transmits 1120, to the UE 102, a first control signal configuring a UE-initiated beam selection for a multiple transmission-reception point (M-TRP) scheme. For example, referring to FIG. 6, the NW entity 104 transmits 620, to the UE, a first control signal (e.g., an RRC signal including an RRC configuration) configuring a UE-initiated beam selection.
[0227] The network entity 104 may transmit 1130, to the UE 102, a second control signal indicating the at least one of the channel or the reference signal to use the one or more UE-selected beams. For example, referring to FIG. 6, the NW entity 104 may then transmit 630 a second control signal for configuring / indicating whether a channel or RS applies / follows the UE-selected (e.g., UE suggested, UE preferred or qualified) beam (s) from the UE-initiated beam selection / switching.
[0228] The network entity 104 receives 1140, from the UE 102, a report indicating one or more UE-selected beams based on the first control signal. For example, referring to FIG. 6, the NW entity 104 receives 640, from the UE, the report indicating the one or more UE-selected beams based on the first control signal.
[0229] The network entity 104 may transmit 1150, to the UE 102, a confirmation message to confirm the one or more UE-selected beams. For example, referring to FIG. 6, the NW entity 104 may feedback or transmit 650 a confirmation message to confirm or approve the one or more UE-selected beams (e.g., UE suggested, UE preferred or qualified beams) indicated by the UE can apply.
[0230] The network entity 104 communicates 1180 with the UE 102, using the one or more UE-selected beams for at least one of a channel or a reference signal for the M-TRP scheme. For example, referring to FIG. 6, the NW entity 104 communicates 680 with the UE 102 using the one or more UE-selected beams for at least one of a channel or a reference signal for the M-TRP scheme.
[0231] FIG. 12 illustrates a flowchart 1200 of a method of wireless communication at a UE for interpreting a PDCCH order according to an embodiment. With reference to FIGs. 1-3B and 7, the method may be performed by the UE 102. In embodiments, the UE 102 receives 1220, from a network entity 104, a control signal including a first field or a second field different from the first field in a PDCCH order. In some examples, the first field indicates that the PDCCH order is for triggering a CFRA for a serving cell or a neighboring cell. In some examples, the first field indicates that the PDCCH order is for triggering the CFRA for the serving cell or a candidate cell. The second field indicates that the PDCCH order is for triggering an LTM procedure for the serving cell or the candidate cell. For example, referring to FIG. 7, a UE 102 receives 720, from a network entity104, a control signal including a first field or a second field different from the first field in a PDCCH order. The first field indicates that the PDCCH order is for triggering a CFRA for a serving cell or a candidate cell. The second field indicates that the PDCCH order is for triggering an LTM procedure for the serving cell or the candidate cell.
[0232] The UE 102 communicates 1280 with the network entity 104 based on at least one of the first field or the second field of the control signal. For example, referring to FIG. 7, the UE 102 communicates 780 with the network entity 104 based on at least one of the first field (e.g., the second DCI field) or the second field (e.g., the third DCI field) of the control signal. FIG. 12 describes a method from a UE-side of a wireless communication link, whereas FIG. 13 describes a method from a network-side of the wireless communication link.
[0233] FIG. 13 is a flowchart 1300 of a method of wireless communication at a network for indicating a PDCCH order according to an embodiment. With reference to FIGs. 1-3B and 7, the method may be performed by one or more network entities 104, which may correspond to a base station or a unit of the base station, such as the RU 106, the DU 108, and / or the CU 110. In embodiments, the network entity 104 transmits 1320, to a UE 102, a control signal including a first field or a second field different from the first field in a PDCCH order. In some example, the first field indicates that the PDCCH order is for triggering a CFRA for a serving cell or a neighboring cell. In some examples, the first field indicates that the PDCCH order is for triggering the CFRA for the serving cell or a candidate cell. The second field indicates that the PDCCH order is for triggering an LTM procedure for the serving cell or the candidate cell. For example, referring to FIG. 7, the network entity 104 transmits 720, to the UE 102, the control signal including the first field or the second field different from the first field in the PDCCH order. The first field indicates that the PDCCH order is for triggering a CFRA for a serving cell or a candidate cell. The second field indicates that the PDCCH order is for triggering an LTM procedure for the serving cell or the candidate cell.
[0234] The network entity 104 communicates 1380 with the UE 102 based on at least one of the first field or the second field of the control signal. For example, referring to FIG. 7, The network entity 104 communicates 780 with the UE 102 based on at least one of the first field (e.g., the second DCI field) or the second field (e.g., the third DCI field) of the control signal. A UE apparatus 1402, as described in FIG. 14, may perform the method of flowchart 800, 1000 and 1200. The one or more network entities 104, as described in FIG. 15, may perform the method of flowchart 900, 1100 and 1300.
[0235] FIG. 14 is a diagram 1400 illustrating an example of a hardware implementation for a UE apparatus 1402. The UE apparatus 1402 may be the UE 102, a component of the UE 102, or may implement UE functionality. The UE apparatus 1402 may include an application processor 1406, which may have on-chip memory 1406’ . In examples, the application processor 1406 may be coupled to a secure digital (SD) card 1408 and / or a display 1410. The application processor 1406 may also be coupled to a sensor (s) module 1412, a power supply 1414, an additional module of memory 1416, a camera 1418, and / or other related components.
[0236] The UE apparatus 1402 may further include a wireless baseband processor 1426, which may be referred to as a modem. The wireless baseband processor 1426 may have on-chip memory 1426'. Along with, and similar to, the application processor 1406, the wireless baseband processor 1426 may also be coupled to the sensor (s) module 1412, the power supply 1414, the additional module of memory 1416, the camera 1418, and / or other related components. The wireless baseband processor 1426 may be additionally coupled to one or more subscriber identity module (SIM) card (s) 1420 and / or one or more transceivers 1430 (e.g., wireless RF transceivers) .
[0237] Within the one or more transceivers 1430, the UE apparatus 1402 may include a Bluetooth module 1432, a WLAN module 1434, an SPS module 1436 (e.g., GNSS module) , and / or a cellular module 1438. The Bluetooth module 1432, the WLAN module 1434, the SPS module 1436, and the cellular module 1438 may each include an on-chip transceiver (TRX) , or in some cases, just a transmitter (TX) or just a receiver (RX) . The Bluetooth module 1432, the WLAN module 1434, the SPS module 1436, and the cellular module 1438 may each include dedicated antennas and / or utilize antennas 1440 for communication with one or more other nodes. For example, the UE apparatus 1402 can communicate through the transceiver (s) 1430 via the antennas 1440 with another UE (e.g., sidelink communication) and / or with a network entity 104 (e.g., uplink / downlink communication) , where the network entity 104 may correspond to a base station or a unit of the base station, such as the RU 106, the DU 108, or the CU 110.
[0238] The wireless baseband processor 1426 and the application processor 1406 may each include a computer-readable medium / memory 1426', 1406', respectively. The additional module of memory 1416 may also be considered a computer-readable medium / memory. Each computer-readable medium / memory 1426', 1406', 1416 may be non-transitory. The wireless baseband processor 1426 and the application processor 1406 may each be responsible for general processing, including execution of software stored on the computer-readable medium / memory 1426', 1406', 1416. The software, when executed by the wireless baseband processor 1426 / application processor 1406, causes the wireless baseband processor 1426 / application processor 1406 to perform the various functions described herein. The computer-readable medium / memory may also be used for storing data that is manipulated by the wireless baseband processor 1426 / application processor 1406 when executing the software. The wireless baseband processor 1426 / application processor 1406 may be a component of the UE 102. The UE apparatus 1402 may be a processor chip (e.g., modem and / or application) and include just the wireless baseband processor 1426 and / or the application processor 1406. In other examples, the UE apparatus 1402 may be the entire UE 102 and include the additional modules of the apparatus 1402.
[0239] As discussed in FIG. 1 and implemented with respect to FIG. 8, the M-TRP component 140 is configured to receive, from a network entity, a first control signal indicating a first set of TCI states. The M-TRP component 140 is configured to receive from the network entity, a second control signal scheduling a PDSCH transmission for a M-TRP scheme. The second control signal is associated with a second set of TCI states. The M-TRP component 140 is configured to receive, from the network entity, the PDSCH transmission using at least one TCI state of the first set of TCI states or using the second set of TCI states based on a configuration of the second control signal.
[0240] As discussed in FIG. 1 and implemented with respect to FIG. 10, the M-TRP component 140 is configured to receive, from a network entity, a first control signal configuring a UE-initiated beam selection for an M-TRP scheme. The M-TRP component 140 is configured to transmit, to the network entity, a report indicating one or more UE-selected beams based on the first control channel. The M-TRP component 140 is configured to communicate with the network entity using the one or more UE-selected beams for at least one of a channel or a reference signal for the M-TRP scheme.
[0241] As discussed in FIG. 1 and implemented with respect to FIG. 12, the M-TRP component 140 is configured to receive, from a network entity, a control signal including a first field or a second field different from the first field in a PDCCH order. In some examples, the first field indicates that the PDCCH order is for triggering a CFRA for a serving cell or a neighboring cell. In some examples, the first field indicates that the PDCCH order is for triggering the CFRA for the serving cell or a candidate cell. The second field indicates that the PDCCH order is for triggering an LTM procedure for the serving cell or a candidate cell. The M-TRP component 140 is configured to communicate with the network entity based on at least one of the first field or the second field of the control signal. The M-TRP component 140 may be within the application processor 1406 (e.g., at 140a) , the wireless baseband processor 1426 (e.g., at 140b) , or both the application processor 1406 and the wireless baseband processor 1426. The M-TRP component 140a-140b may be one or more hardware components specifically configured to carry out the stated processes / algorithm, implemented by one or more processors configured to perform the stated processes / algorithm, stored within a computer-readable medium for implementation by the one or more processors, or a combination thereof.
[0242] FIG. 15 is a diagram 1500 illustrating an example of a hardware implementation for one or more network entities 104. The one or more network entities 104 may be a base station, a component of a base station, or may implement base station functionality. The one or more network entities 104 may include, or may correspond to, at least one of the RU 106, the DU, 108, or the CU 110. The CU 110 may include a CU processor 1546, which may have on-chip memory 1546'. In some aspects, the CU 110 may further include an additional module of memory 1556 and / or a communications interface 1548, both of which may be coupled to the CU processor 1546. The CU 110 can communicate with the DU 108 through a midhaul link 162, such as an F1 interface between the communications interface 1548 of the CU 110 and a communications interface 1528 of the DU 108.
[0243] The DU 108 may include a DU processor 1526, which may have on-chip memory 1526'. In some aspects, the DU 108 may further include an additional module of memory 1536 and / or the communications interface 1528, both of which may be coupled to the DU processor 1526. The DU 108 can communicate with the RU 106 through a fronthaul link 160 between the communications interface 1528 of the DU 108 and a communications interface 1508 of the RU 106.
[0244] The RU 106 may include an RU processor 1506, which may have on-chip memory 1506'. In some aspects, the RU 106 may further include an additional module of memory 1516, the communications interface 1508, and one or more transceivers 1530, all of which may be coupled to the RU processor 1506. The RU 106 may further include antennas 1540, which may be coupled to the one or more transceivers 1530, such that the RU 106 can communicate through the one or more transceivers 1530 via the antennas 1540 with the UE 102.
[0245] The on-chip memory 1506', 1526', 1546' and the additional modules of memory 1516, 1536, 1556 may each be considered a computer-readable medium / memory. Each computer-readable medium / memory may be non-transitory. Each of the processors 1506, 1526, 1546 is responsible for general processing, including execution of software stored on the computer-readable medium / memory. The software, when executed by the corresponding processor (s) 1506, 1526, 1546 causes the processor (s) 1506, 1526, 1546 to perform the various functions described herein. The computer-readable medium / memory may also be used for storing data that is manipulated by the processor (s) 1506, 1526, 1546 when executing the software. In examples, the configuration component 150 may sit at any of the one or more network entities 104, such as at the CU 110; both the CU 110 and the DU 108; each of the CU 110, the DU 108, and the RU 106; the DU 108; both the DU 108 and the RU 106; or the RU 106.
[0246] As discussed in FIG. 1 and implemented with respect to FIG. 9, the configuration component 150 is configured to transmit, to a UE, a first control signal indicating a first set of transmission configuration indicator (TCI) states. The configuration component 150 is configured to transmit, to the UE, a second control signal scheduling a PDSCH transmission for an M-TRP scheme. The second control signal is associated with a second set of TCI states. The configuration component 150 is configured to transmit, to the UE 102, the PDSCH transmission using at least one TCI state of the first set of TCI states or using the second set of TCI states based on a configuration of the second control signal.
[0247] As discussed in FIG. 1 and implemented with respect to FIG. 9, the configuration component 150 is configured to transmit, to a UE, a first control signal configuring UE-initiated beam selection for a multiple transmission-reception point (M-TRP) scheme. The configuration component 150 is configured to receive, from the UE, a report indicating one or more UE-selected beams based on the first control channel. The configuration component 150 is configured to communicate with the UE using the one or more UE-selected beams for at least one of a channel or a reference signal for the M-TRP scheme.
[0248] As discussed in FIG. 1 and implemented with respect to FIG. 9, the configuration component 150 is configured to transmit, to a UE, a control signal including a first field or a second field different from the first field in a PDCCH order. In some examples, the first field indicates that the PDCCH order is for triggering a CFRA for a serving cell or a neighboring cell. In some examples, the first field indicates that the PDCCH order is for triggering the CFRA for the serving cell or a candidate cell. The second field indicates that the PDCCH order is for triggering an LTM procedure for the serving cell or a candidate cell. The configuration component 150 is configured to communicates with the UE based on at least one of the first field or the second field of the control signal. The configuration component 150 may be within one or more processors of the one or more network entities 104, such as the RU processor 1506 (e.g., at 150a) , the DU processor 1526 (e.g., at 150b) , and / or the CU processor 1546 (e.g., at 150c) . The configuration component 150a-150c may be one or more hardware components specifically configured to carry out the stated processes / algorithm, implemented by one or more processors 1506, 1526, 1546 configured to perform the stated processes / algorithm, stored within a computer-readable medium for implementation by the one or more processors 1506, 1526, 1546, or a combination thereof.
[0249] It is noted that throughout this disclosure, the UE may have one or more of the following attributes or behaviors. The following attributes or behaviors of the UE may also imply associated attributes or behaviors of a NW entity.
[0250] ● The UE may be configured with and / or served by the NW entity in a serving cell.
[0251] ● The UE may (be configured to) communicate with the NW entity in the serving cell.
[0252] ● The UE may be configured with one or more serving cells by the NW entity, which may include the serving cell.
[0253] ● The UE may be activated or be indicated, by the NW entity, to activate one or more serving cells, which may include the serving cell.
[0254] ● The UE may be configured and / or indicated, by the NW entity, one or more BWP. The UE may be indicated and / or configured, by the NW entity, a BWP (in the serving cell) .
[0255] ○ In some cases, the BWP may be activated as an active BWP.
[0256] ○ In some cases, the BWP may be referred to an active BWP
[0257] ○ In some cases, the BWP may be an active DL BWP.
[0258] ○ In some cases, the BWP may be an active UL BWP.
[0259] ○ In some cases, the BWP may be an initial BWP.
[0260] ○ In some cases, the BWP may be a default BWP.
[0261] ○ In some cases, the BWP may be a dormant BWP.
[0262] ● The UE may be in one of RRC_CONNECTED state, RRC_INACTIVE state or RRC_IDLE state.
[0263] It is noted that throughout this disclosure, when a procedure or description is related to a serving cell, it may mean the procedure or description is related to an active (DL / UL) BWP in the serving cell.
[0264] It is noted that throughout this disclosure, a neighboring cell can be referred to or replaced with one or some of the followings:
[0265] ● Non-serving cell,
[0266] ● A cell with PCI different that of the serving cell,
[0267] ● A TRP associated with a PCI different from that of the serving cell.
[0268] It is noted that throughout this disclosure, if the NW entity configures the UE inter-cell M-TRP 2TA in a serving cell, it may imply that the NW entity configures two TAGs to be associated with the serving cell, where one TAG is associated with serving cell PCI and the other TAG is associated with additional PCI in the serving cell. The additional PCI may be associated with or configured in an activated TCI state for the serving cell.
[0269] It is noted that throughout this disclosure, if the NW entity configures the UE intra-cell M-TRP 2TA, it may imply that the NW entity configures two TAGs to be associated with a serving cell, where both TAG are associated with serving cell and / or no additional PCI is configured.
[0270] It is noted that throughout this disclosure, a scheduling CORESET could mean or be referred to as a CORESET with a scheduling PDCCH. A scheduling CORESET for a PDSCH could mean or be referred to as a CORESET with a PDCCH or DCI scheduling the PDSCH.
[0271] It is noted that throughout this disclosure, an action time of a TCI state or beam indication could mean the actual timing when the TCI state or beam indication is applicable or takes effect, which could be later than the timing of receiving the TCI state or beam indication.
[0272] It is noted that throughout this disclosure, for case (s) that a NW entity configures or indicates the UE to operate with the S-TRP mode in a serving cell or a BWP, or for case (s) that a serving cell or a BWP is operated with the S-TRP mode, it can imply or be referred to be one of the followings:
[0273] - No TRP identifier or no TRP-related index is configured or indicated, by the NW entity, to any channel or RS in the serving cell or BWP, and / or
[0274] - (only) One TRP identifier or TRP-related index is configured or indicated, by the NW entity, to any channel or RS in the serving cell or BWP, and / or
[0275] - When the UE or the NW entity transmits / receives a transmission, (only) one TRP identifier or TRP-related index is configured or indicated or involved to the transmission or the beam / TCI state applied for the transmission.
[0276] It is noted that throughout this disclosure, for case (s) that a NW entity configures or indicates the UE to operate with the M-TRP mode in a serving cell or a BWP, or for case (s) that a serving cell or a BWP is operated with the M-TRP mode, it can imply or be referred to be one of the followings:
[0277] - More than one TRP identifier or TRP-related index is configured or indicated, by the NW entity, to at least one channel or RS in the serving cell or BWP, and / or
[0278] - One TRP identifier or TRP-related index is configured or indicated, by the NW entity, to one channel or RS in the serving cell or BWP; and the UE derives or determines another one TRP identifier or TRP-related index applied for or associated with at least one channel or RS in the serving cell or BWP, and / or
[0279] - When the UE or the NW entity transmits / receives a transmission, more than one TRP identifier or TRP-related index is configured or indicated or involved to the transmission or the beam / TCI state applied for the transmission, and / or
[0280] - The NW entity configures, to the UE, a higher layer parameter PDCCH-Config that contains two different values of coresetPoolIndex in ControlResourceSet in the serving cell or BWP, and / or
[0281] - The UE receives, from the NW entity, a MAC-CE (e.g., PDSCH TCI activation MAC-CE) in the serving cell or BWP, which indicates that at least one TCI codepoint is mapped to two TCI states.
[0282] It is noted that throughout this disclosure, for case (s) that a NW entity configures or indicates the UE to operate with (M-TRP) M-DCI mode in a serving cell or a BWP, or for case (s) that a serving cell or a BWP is operated with (M-TRP) M-DCI mode, it can imply or be referred to be one of the followings:
[0283] - More than one TRP identifier or TRP-related index is configured or indicated, by the NW entity, to at least one channel or RS in the serving cell or BWP, and / or
[0284] - One TRP identifier or TRP-related index is configured or indicated, by the NW entity, to one channel or RS in the serving cell or BWP; and the UE derives or determines another one TRP identifier or TRP-related index applied for or associated with at least one channel or RS in the serving cell or BWP, and / or
[0285] - The NW entity configures, to the UE, a higher layer parameter PDCCH-Config that contains two different values of coresetPoolIndex in ControlResourceSet in the serving cell or BWP.
[0286] It is noted that throughout this disclosure, for case (s) that a NW entity configures or indicates the UE to operate with (M-TRP) S-DCI mode in a serving cell or a BWP, or for case (s) that a serving cell or a BWP is operated with (M-TRP) S-DCI mode, it can imply or be referred to be one of the followings:
[0287] - When the UE or the NW entity transmits / receives a transmission, more than one TRP identifier or TRP-related index is configured or indicated or involved to the transmission or the beam / TCI state applied for the transmission, and / or
[0288] - The UE receives, from the NW entity, a MAC-CE (e.g., PDSCH TCI activation MAC-CE) in the serving cell or BWP, which indicates that at least one TCI codepoint is mapped to two TCI states, each of which is associated with different TRP or different TRP identifier (value) .
[0289] ○ For example, at least one TCI codepoint is mapped to two joint TCI states, each of which is associated with different TRP or different TRP identifier (value) . For another example, at least one TCI codepoint is mapped to two DL TCI states or two UL TCI states, each of which is associated with different TRP or different TRP identifier (value) . For another example, at least one TCI codepoint is mapped to a DL TCI state and a pair of DL TCI state and UL TCI state, where the DL TCI state and the pair is associated with different TRP or different TRP identifier (value) .
[0290] It is noted that throughout this disclosure, a TRP identifier could mean or be referred to a (candidate) value of a TRP identifier. The first TRP identifier could be a first candidate value of a TRP identifier or a first TRP identifier value. The second TRP identifier could be a second candidate value of a TRP identifier or a second TRP identifier value.
[0291] It is noted that throughout this disclosure, an expression of “X / Y” may include meaning of “X or Y” . It is noted that throughout this disclosure, an expression of “X / Y” may include meaning of “X and Y” . It is noted that throughout this disclosure, an expression of “X / Y” may include meaning of “X and / or Y” . It is noted that throughout this disclosure, an expression of “ (A) B” or “B (A) ” may include concept of “only B” . It is noted that throughout this disclosure, an expression of “ (A) B” or “B (A) ” may include concept of “A+B” or “B+A” .
[0292] It is noted that some or all of the foregoing or the following embodiments could be jointly combined or formed to be a new or another one embodiment.
[0293] It is noted that the foregoing or the following embodiments can be used to solve at least (but not limited to) the issue (s) or scenario (s) mentioned in this disclosure.
[0294] The following additional considerations may apply to the foregoing and the following discussions.
[0295] It is noted that any two or more than two of the foregoing or the following paragraphs, (sub) -bullets, points, actions, or claims described in each method / embodiment / implementation may be combined logically, reasonably, and properly to form a specific method.
[0296] It is noted that any sentence, paragraph, (sub) -bullet, point, action, or claim described in each of the foregoing or the following embodiment (s) / implementation (s) / concept (s) may be implemented independently and separately to form a specific method. Dependency, e.g. “based on” , “more specifically” , “where” or etc., in embodiment (s) / implementation (s) / concept (s) mentioned in this disclosure is just one possible embodiment which would not restrict the specific method.
[0297] It is noted that, some or all of the following terminology and assumption may be used hereafter.
[0298] BS: a network central unit or a network node in NR which is used to control one or multiple TRPs which are associated with one or multiple cells. Communication between BS and TRP (s) is via fronthaul. BS may be referred to as central unit (CU) , eNB, gNB, or NodeB.
[0299] TRP: a transmission and reception point provides network coverage and directly communicates with UEs. TRP may be referred to as distributed unit (DU) or network node.
[0300] Cell: a cell is composed of one or multiple associated TRPs, i.e. coverage of the cell is composed of coverage of all associated TRP (s) . One cell is controlled by one BS or a NW entity. Cell may be referred to as TRP group (TRPG) .
[0301] Serving beam: serving beam for a UE is a beam generated by a network node, e.g. TRP, which is configured to be used to communicate with the UE, e.g. for transmission and / or reception.
[0302] Candidate beam: candidate beam for a UE is a candidate of a serving beam. Serving beam may or may not be candidate beam.
[0303] A user device in which the techniques of this disclosure can be implemented (e.g., the UE 102) can be any suitable device capable of wireless communications such as a smartphone, a tablet computer, a laptop computer, a mobile gaming console, a point-of-sale (POS) terminal, a health monitoring device, a drone, a camera, a media-streaming dongle or another personal media device, a wearable device such as a smartwatch, a wireless hotspot, a femtocell, or a broadband router. Further, the user device in some cases may be embedded in an electronic system such as the head unit of a vehicle or an advanced driver assistance system (ADAS) . Still further, the user device can operate as an internet-of-things (IoT) device or a mobile-internet device (MID) . Depending on the type, the user device can include one or more general- purpose processors, a computer-readable memory, a user interface, one or more network interfaces, one or more sensors, etc.
[0304] Certain embodiments are described in this disclosure as including logic or a number of components or modules. Modules may can be software modules (e.g., code stored on non-transitory machine-readable medium) or hardware modules. A hardware module is a tangible unit capable of performing certain operations and may be configured or arranged in a certain manner. A hardware module can comprise dedicated circuitry or logic that is permanently configured (e.g., as a special-purpose processor, such as a field programmable gate array (FPGA) or an application-specific integrated circuit (ASIC) ) to perform certain operations. A hardware module may also comprise programmable logic or circuitry (e.g., as encompassed within a general-purpose processor or other programmable processor) that is temporarily configured by software to perform certain operations. The decision to implement a hardware module in dedicated and permanently configured circuitry, or in temporarily configured circuitry (e.g., configured by software) may be driven by cost and time considerations.
[0305] When implemented in software, the techniques can be provided as part of the operating system, a library used by multiple applications, a particular software application, etc. The software can be executed by one or more general-purpose processors or one or more special-purpose processors.
[0306] The specific order or hierarchy of blocks in the processes and flowcharts disclosed herein is an illustration of example approaches. Hence, the specific order or hierarchy of blocks in the processes and flowcharts may be rearranged. Some blocks may also be combined or deleted. Dashed lines may indicate optional elements of the diagrams. The accompanying method claims present elements of the various blocks in an example order, and are not limited to the specific order or hierarchy presented in the claims, processes, and flowcharts.
[0307] The detailed description set forth herein describes various configurations in connection with the drawings and does not represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough explanation of various concepts. However, these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts.
[0308] Aspects of wireless communication systems, such as telecommunication systems, are presented with reference to various apparatuses and methods. These apparatuses and methods are described in the following detailed description and are illustrated in the accompanying drawings by various blocks, components, circuits, processes, call flows, systems, algorithms, etc. (collectively referred to as “elements” ) . These elements may be implemented using electronic hardware, computer software, or combinations thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.
[0309] An element, or any portion of an element, or any combination of elements may be implemented as a “processing system” that includes one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs) , central processing units (CPUs) , application processors, digital signal processors (DSPs) , reduced instruction set computing (RISC) processors, systems-on-chip (SoC) , baseband processors, field programmable gate arrays (FPGAs) , programmable logic devices (PLDs) , state machines, gated logic, discrete hardware circuits, and other similar hardware configured to perform the various functionality described throughout this disclosure. One or more processors in the processing system may execute software, which may be referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, or any combination thereof.
[0310] If the functionality described herein is implemented in software, the functions may be stored on, or encoded as, one or more instructions or code on a computer-readable medium, such as a non-transitory computer-readable storage medium. Computer-readable media includes computer storage media and can include a random-access memory (RAM) , a read-only memory (ROM) , an electrically erasable programmable ROM (EEPROM) , optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of these types of computer-readable media, or any other medium that can be used to store computer executable code in the form of instructions or data structures that can be accessed by a computer. Storage media may be any available media that can be accessed by a computer.
[0311] Aspects, implementations, and / or use cases described herein may be implemented across many differing platform types, devices, systems, shapes, sizes, and packaging arrangements. For example, the aspects, implementations, and / or use cases may come about via integrated chip implementations and other non-module-component based devices, such as end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail / purchasing devices, medical devices, artificial intelligence (AI) -enabled devices, machine learning (ML) -enabled devices, etc. The aspects, implementations, and / or use cases may range from chip-level or modular components to non-modular or non-chip-level implementations, and further to aggregate, distributed, or original equipment manufacturer (OEM) devices or systems incorporating one or more techniques described herein.
[0312] Devices incorporating the aspects and features described herein may also include additional components and features for the implementation and practice of the claimed and described aspects and features. For example, transmission and reception of wireless signals necessarily includes a number of components for analog and digital purposes, such as hardware components, antennas, RF-chains, power amplifiers, modulators, buffers, processor (s) , interleavers, adders / summers, etc. Techniques described herein may be practiced in a wide variety of devices, chip-level components, systems, distributed arrangements, aggregated or disaggregated components, end-user devices, etc., of varying configurations.
[0313] The description herein is provided to enable a person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not limited to the aspects described herein, but are to be interpreted in view of the full scope of the present disclosure consistent with the language of the claims.
[0314] Reference to an element in the singular does not mean “one and only one” unless specifically stated, but rather “one or more. ” Terms such as “if, ” “when, ” and “while” do not imply an immediate temporal relationship or reaction. That is, these phrases, e.g., “when, ” do not imply an immediate action in response to or during the occurrence of an action, but simply imply that if a condition is met then an action will occur, but without requiring a specific or immediate time constraint for the action to occur. The terms “may” , “might” , and “can” , as used in this disclosure, often carry certain connotations. For example, “may” refers to a permissible feature that may or may not occur, “might” refers to a feature that probably occurs, and “can” refers to a capability (e.g., capable of) . The phrase “For example” often carries a similar connotation to “may” and, therefore, “may” is sometimes excluded from sentences that include “for example” or other similar phrases.
[0315] Unless specifically stated otherwise, the term “some” refers to one or more. Combinations such as “at least one of A, B, or C” or “one or more of A, B, or C”include any combination of A, B, and / or C, such as A and B, A and C, B and C, or A and B and C, and may include multiples of A, multiples of B, and / or multiples of C, or may include A only, B only, or C only. Sets should be interpreted as a set of elements where the elements number one or more. Terms or articles such as “a” , “an” , and / or “the” may refer to one of an item, feature, element, etc., that the term or article precedes, or may refer to more than one of said item, feature, element, etc. that the term or article precedes. For example, the recitation “a widget” does not preclude reference to multiples of said widget, as “multiple widgets” necessarily includes “awidget” . Hence, the recitation “a widget” may be interpreted as “at least one widget” or, similarly, interpreted as “one or more widgets” .
[0316] Unless otherwise specifically indicated, ordinal terms such as “first” and “second” do not necessarily imply an order in time, sequence, numerical value, etc., but are used to distinguish between different instances of a term or phrase that follows each ordinal term.
[0317] Reference numbers, as used in the specification and figures, are sometimes cross-referenced among drawings to denote same or similar features. A feature that is exactly the same in multiple drawings may be labeled with the same reference number in the multiple drawings. A feature that is similar among the multiple drawings, but not exactly the same, may be labeled with reference numbers that have different leading numbers but have one or more of the same trailing numbers (e.g., 206, 306, 406, etc., may refer to similar features in the drawings) . Hence, like numbers may refer to like actions.
[0318] Structural and functional equivalents to elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are encompassed by the claims. The words “module, ” “mechanism, ” “element, ” “device, ” and the like may not be a substitute for the word “means. ” As such, no claim element is to be construed as a means plus function unless the element is expressly recited using the phrase “means for. ” As used herein, the phrase “based on” shall not be construed as a reference to a closed set of information, one or more conditions, one or more factors, or the like. In other words, the phrase “based on A” , where “A” may be information, a condition, a factor, or the like, shall be construed as “based at least on A” unless specifically recited differently.
[0319] The following examples are illustrative only and may be combined with other examples or teachings described herein, without limitation.
[0320] Example 1 is a method of wireless communication at a UE, including: receiving, from a network entity, a first control signal indicating a first set of transmission configuration indicator (TCI) states; receiving, from the network entity, a second control signal scheduling a physical downlink shared channel (PDSCH) transmission for a multiple transmission-reception point (M-TRP) scheme, the second control signal being associated with a second set of TCI states; and receiving, from the network entity, the PDSCH transmission using at least one TCI state of the first set of TCI states or using the second set of TCI states based on a configuration of the second control signal.
[0321] Example 2 may be combined with example 1 and includes that transmitting, to the network entity, a UE capability report indicating a UE capability of the UE (102) for supporting the M-TRP scheme.
[0322] Example 3 may be combined with any of the examples 1-2 and further includes that the second control signal is a downlink control information (DCI) on a physical downlink control channel (PDCCH) in a control resource set (CORESET) , the method further includes receiving, from the network entity (104) , at least one of a TCI selection parameter or a TCI selection field indicating at least one TCI state of the first set of TCI states.
[0323] Example 4 may be combined with any of the examples 1-3 and further includes that the receiving, from the network entity, the PDSCH transmission includes receiving the PDSCH transmission using the at least one TCI state of the first set of TCI states based on the configuration of the second control signal indicating the second set of TCI states is same as the first set of TCI states, wherein the at least one TCI state is further based on a DCI format.
[0324] Example 5 may be combined with any of the examples 1-3 and further includes that the receiving, from the network entity, the PDSCH transmission includes based on the DCI format being a second DCI format, receiving the PDSCH transmission using the at least one TCI state of the first set of TCI states based on a TCI selection field; or based on the DCI format being a first DCI format, receiving (480, 580-2c, 580-3c) the PDSCH transmission using the at least one TCI state of the first set of TCI states based on a TCI selection parameter or using the second set of TCI states based on the configuration of the second control signal indicating the second set of TCI states is same or different than the first set of TCI states respectively.
[0325] Example 6 may be combined with any of the examples 1-3 and further includes that the receiving, from the network entity, the PDSCH transmission includes receiving the PDSCH transmission using the at least one TCI state of the first set of TCI states based on the configuration of the second control signal indicating the second set of TCI states is different than the first set of TCI states. The at least one TCI state is based on a TCI selection parameter or a TCI selection field associated with a DCI format.
[0326] Example 7 may be combined with any of the examples 1-3 and further includes that the receiving the PDSCH transmission is further based on a UE capability.
[0327] Example 8 is a method of wireless communication at a network entity, including: transmitting, to a UE, a first control signal indicating a first set of transmission configuration indicator (TCI) states; transmitting, to the UE, a second control signal scheduling a physical downlink shared channel (PDSCH) transmission for a multiple transmission-reception point (M-TRP) scheme, the second control signal being associated with a second set of TCI states and transmitting, to the UE, the PDSCH transmission using at least one TCI state of the first set of TCI states or using the second set of TCI states based on a configuration of the second control signal.
[0328] Example 9 may be combined with example 8 and further includes that receiving, from the UE, a UE capability report indicating a UE capability of the UE for supporting the M-TRP scheme.
[0329] Example 10 may be combined with any of the examples 8-9 and further includes that the transmitting, to the UE, the PDSCH transmission includes: transmitting the PDSCH transmission using the at least one TCI state of the first set of TCI states based on the configuration of the second control signal indicating the second set of TCI states is same as the first set of TCI states, wherein the at least one TCI state is further based on a DCI format.
[0330] Example 11 may be combined with any of the examples 8-9 and further includes that the transmitting, to the UE, the PDSCH transmission includes: based on the DCI format being a second DCI format, transmitting the PDSCH transmission using at least one TCI state of the first set of TCI states based on a TCI selection field; or based on the DCI format being a first DCI format, transmitting the PDSCH transmission using at least one TCI state of the first set of TCI states based on a TCI selection parameter or using the second set of TCI states based on the configuration of the second control signal indicating the second set of TCI states is same or different than the first set of TCI states respectively.
[0331] Example 12 may be combined with any of the examples 8-9 and further includes that the transmitting, to the UE, the PDSCH transmission includes: transmitting the PDSCH transmission using at least one TCI state of the first set of TCI states based on the configuration of the second control signal indicating the second set of TCI states is different than the first set of TCI states. The at least one TCI state is based on a TCI selection parameter or a TCI selection field associated with a DCI format.
[0332] Example 13 is a method of wireless communication at a UE, including: receiving (620) , from a network entity (104) , a first control signal configuring UE-initiated beam selection for a multiple transmission-reception point (M-TRP) scheme; transmitting (640) , to the network entity (104) , a report indicating one or more UE-selected beams based on the first control signal; and communicating (680) with the network entity (104) using the one or more UE-selected beams for at least one of a channel or a reference signal for the M-TRP scheme.
[0333] Example 14 may be combined with example 13 and includes that transmitting (610) , to the network entity (104) , a UE capability report indicating a UE capability of the UE (102) for supporting the M-TRP scheme based on the UE-initiated beam selection; and receiving (650) , from the network entity (104) , a confirmation message to confirm the one or more UE-selected beams.
[0334] Example 15 may be combined with any of the examples 13-14 and further includes that receiving (630) , from the network entity, a second control signal indicating the at least one of the channel or the reference signal to use the one or more UE-selected beams.
[0335] Example 16 may be combined with any of the examples 13-14 and further includes that the report further indicates the at least one of the channel or the reference signal to use the one or more UE-selected beams.
[0336] Example 17 is a method of wireless communication at a network entity, including: transmitting (620) , to a user equipment (UE) (102) , a first control signal configuring UE-initiated beam selection for a multiple transmission-reception point (M-TRP) scheme; receiving (640) , from the UE (102) , a report indicating one or more UE-selected beams based on the first control signal; and communicating (680) with the UE (102) using the one or more UE-selected beams for at least one of a channel or a reference signal for the M-TRP scheme.
[0337] Example 18 may be combined with example 17 and includes that receiving (610) , from the UE (102) , a UE capability report indicating a UE capability of the UE (102) for supporting the M-TRP scheme based on the UE-initiated beam selection; and transmitting (650) , to the UE (102) , a confirmation message to confirm the one or more UE-selected beams.
[0338] Example 19 may be combined with any of the examples 17-18 and further includes that transmitting (630) , to the UE (102) , a second control signal indicating the at least one of the channel or the reference signal to use the one or more UE-selected beams.
[0339] Example 20 may be combined with any of the examples 17-18 and further includes that the report further indicates the at least one of the channel or the reference signal to use the one or more UE-selected beams.
[0340] Example 21 is a method of wireless communication at a UE, including: receiving, from a network entity (104) , a control signal including a first field or a second field different from the first field in a physical downlink control channel (PDCCH) order, the first field indicating that the PDCCH order is for triggering contention-free random access (CFRA) for a serving cell or a candidate cell, the second field indicating that the PDCCH order is for triggering a lower-layer triggered mobility (LTM) procedure for the serving cell or the candidate cell; and communicating with the network entity (104) based on at least one of the first field or the second field of the control signal.
[0341] Example 22 may be combined with example 21 and includes that the first field is a physical random access channel (PRACH) configuration field, and the second field is a cell indicator field.
[0342] Example 23 may be combined with any of the examples 21-22 and further includes that the communicating with the network entity (104) includes: communicating with the network entity (104) based on the first field when the second field indicates the serving cell.
[0343] Example 24 may be combined with any of the examples 21-22 and further includes that the communicating with the network entity (104) includes: communicating with the network entity (104) based on the second field when the first field indicates that the PDCCH order is associated with the serving cell.
[0344] Example 25 may be combined with any of the examples 21-22 and further includes that the control signal further includes a third field indicating whether to apply the at least one of the first field or the second field in the PDCCH order.
[0345] Example 26 is a method of wireless communication at a network entity, including: transmitting, to a user equipment (UE) (102) , a control signal including a first field or a second field different from the first field in a physical downlink control channel (PDCCH) order, the first field indicating that the PDCCH order is for triggering contention-free random access (CFRA) for a serving cell or a candidate cell, the second field indicating that the PDCCH order is for triggering a lower-layer triggered mobility (LTM) procedure for the serving cell or the candidate cell; and communicating with the UE (102) based on at least one of the first field or the second field of the control signal.
[0346] Example 27 may be combined with example 26 and includes that the first field is a physical random access channel (PRACH) configuration field, and wherein the second field is a cell indicator field.
[0347] Example 28 may be combined with any of the examples 26-27 and further includes that the communicating with the UE (102) includes: communicating with the UE (102) based on the first field when the second field indicates the serving cell.
[0348] Example 29 may be combined with any of the examples 26-27 and further includes that the communicating with the UE (102) includes: communicating with the UE (102) based on the second field when the first field indicates that the PDCCH order is associated with the serving cell.
[0349] Example 30 may be combined with any of the examples 26-27 and further includes that the control signal further includes a third field indicating whether to apply the at least one of the first field or the second field in the PDCCH order.
[0350] Example 31 is an apparatus for wireless communication including a transceiver, a memory, and a processor coupled to the memory and the transceiver. The apparatus is configured to implement a method as in any of claims 1-30.
[0351] Example 32 is an apparatus for wireless communication including means for implementing a method as in any of examples 1-30.
[0352] Example 33 is a non-transitory computer-readable medium storing computer executable code, the code when executed by a processor causes the processor to implement a method as in any of examples 1-30.
Claims
1.A method of wireless communication at a user equipment (UE) (102) , comprising:receiving (440, 450) , from a network entity (104) , a first control signal indicating a first set of transmission configuration indicator (TCI) states;receiving (460) , from the network entity (104) , a second control signal scheduling a physical downlink shared channel (PDSCH) transmission for a multiple transmission-reception point (M-TRP) scheme, the second control signal being associated with a second set of TCI states; andreceiving (480) , from the network entity (104) , the PDSCH transmission using at least one TCI state of the first set of TCI states or using the second set of TCI states based on a configuration of the second control signal.2.The method of claim 1, further comprising:transmitting (410) , to the network entity (104) , a UE capability report indicating a UE capability of the UE (102) for supporting the M-TRP scheme.3.The method of any of claims 1-2, wherein the second control signal is a downlink control information (DCI) on a physical downlink control channel (PDCCH) in a control resource set (CORESET) , the method further comprising:receiving (430, 450) , from the network entity (104) , at least one of a TCI selection parameter or a TCI selection field indicating at least one TCI state of the first set of TCI states.4.The method of any of claims 1-3, wherein the receiving (480) , from the network entity (104) , the PDSCH transmission comprises:receiving (480, 580-1a, 580-2a) the PDSCH transmission using the at least one TCI state of the first set of TCI states based on the configuration of the second control signal indicating the second set of TCI states is same as the first set of TCI states, wherein the at least one TCI state is further based on a DCI format.5.The method of any of claims 1-3, wherein the receiving (480) , from the network entity (104) , the PDSCH transmission comprises:based on the DCI format being a second DCI format, receiving (480, 580-1c) the PDSCH transmission using the at least one TCI state of the first set of TCI states based on a TCI selection field; orbased on the DCI format being a first DCI format, receiving (480, 580-2c, 580-3c) the PDSCH transmission using the at least one TCI state of the first set of TCI states based on a TCI selection parameter or using the second set of TCI states based on the configuration of the second control signal indicating the second set of TCI states is same or different than the first set of TCI states respectively.6.The method of any of claims 1-3, wherein the receiving (480) , from the network entity (104) , the PDSCH transmission comprises:receiving (480, 580-1b, 580-2b) the PDSCH transmission using the at least one TCI state of the first set of TCI states based on the configuration of the second control signal indicating the second set of TCI states is different than the first set of TCI states, wherein the at least one TCI state is based on a TCI selection parameter or a TCI selection field associated with a DCI format.7.The method of any of claims 1-3, wherein the receiving (480) the PDSCH transmission is further based on a UE capability.8.A method of wireless communication at a network entity (104) , comprising:transmitting (440, 450) , to a user equipment (UE) (102) , a first control signal indicating a first set of transmission configuration indicator (TCI) states;transmitting (460) , to the UE (102) , a second control signal scheduling a physical downlink shared channel (PDSCH) transmission for a multiple transmission-reception point (M-TRP) scheme, the second control signal being associated with a second set of TCI states andtransmitting (480) , to the UE (102) , the PDSCH transmission using at least one TCI state of the first set of TCI states or using the second set of TCI states based on a configuration of the second control signal.9.The method of claim 8, further comprising:receiving (410) , from the UE (102) , a UE capability report indicating a UE capability of the UE (102) for supporting the M-TRP scheme.10.The method of any of claims 8-9, wherein the transmitting (480) , to the UE (102) , the PDSCH transmission comprises:transmitting (480, 580-1a, 580-2a) the PDSCH transmission using the at least one TCI state of the first set of TCI states based on the configuration of the second control signal indicating the second set of TCI states is same as the first set of TCI states, wherein the at least one TCI state is further based on a DCI format.11.The method of any of claims 8-9, wherein the transmitting (480) , to the UE (102) , the PDSCH transmission comprises:based on the DCI format being a second DCI format, transmitting (480, 580-1c) the PDSCH transmission using at least one TCI state of the first set of TCI states based on a TCI selection field; orbased on the DCI format being a first DCI format, transmitting (480, 580-2c, 580-3c) the PDSCH transmission using at least one TCI state of the first set of TCI states based on a TCI selection parameter or using the second set of TCI states based on the configuration of the second control signal indicating the second set of TCI states is same or different than the first set of TCI states respectively.12.The method of any of claims 8-9, wherein the transmitting (480) , to the UE (102) , the PDSCH transmission comprises:transmitting (480, 580-1b, 580-2b) the PDSCH transmission using at least one TCI state of the first set of TCI states based on the configuration of the second control signal indicating the second set of TCI states is different than the first set of TCI states, wherein the at least one TCI state is based on a TCI selection parameter or a TCI selection field associated with a DCI format.13.An apparatus for wireless communication comprising a transceiver, a memory, and a processor coupled to the memory and the transceiver, the apparatus being configured to implement a method as in any of claims 1-12.