Method for default pathloss reference signal and beam
By employing default beams and PL-RS in 5G NR wireless communication systems, the complexity of beam management in 5G NR is mitigated, enhancing communication reliability and reducing overhead in FR 2 communications.
Patent Information
- Application Number
- PCT/CN2023/129643
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2023-11-03
- Publication Date
- 2025-05-08
AI Technical Summary
The unified transmission configuration indicator (TCI) scheme in 5G NR wireless communication systems increases overhead and reduces communication reliability due to complex beam management procedures, especially in Frequency Range 2 (FR 2) communications.
Implementing default beam and pathloss-reference signal (PL-RS) techniques that allow user equipment (UE) to communicate with the network entity using pre-configured default beams and PL-RS, based on quasi-co-location (QCL) parameters or uplink spatial transmission filters, thereby reducing the need for explicit beam indication signaling.
This approach reduces the overhead of beam indication signaling operations, prevents beam mismatch situations, and improves channel performance for both downlink and uplink communications before the UE applies indicated TCI states.
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Figure CN2023129643_08052025_PF_FP_ABST
Abstract
Description
METHOD FOR DEFAULT PATHLOSS REFERENCE SIGNAL AND BEAMTECHNICAL FIELD
[0001] The present disclosure relates generally to wireless communication, and more particularly, to default beam and default pathloss reference signal (PL-RS) .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, 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, a unified transmission configuration indicator (TCI) scheme is designed to streamline beam management for multi-beam operations. The unified TCI scheme may cause multiple scenarios that require highly efficient beam management procedures to handle these scenarios.
[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] Next generation communication systems (e.g., five generation (5G) and sixth generation (6G) wireless technology) use beam management techniques to improve throughput to meet wireless user requirements. Beam management techniques are increasingly complicated because of an adoption of higher frequency bands, user mobility, and an increased antenna count. Specifically, in Frequency Range 2 (FR 2) based communications, the overhead associated with beam management operations and new beams reporting might increase, which might lead to reduced communication reliability. To overcome the communication reliability, a unified transmission configuration indicator (TCI) scheme is designed to streamline beam management for multi-beam operations. The unified TCI scheme enables a network entity to transmit at least one joint TCI state or a unified TCI state to a user equipment (UE) . The network entity configures the joint or uplink unified TCI states in the initial radio control resource (RRC) configuration or RRC reconfiguration.
[0007] However, a unified TCI scheme may cause multiple scenarios that require highly efficient beam management procedures to handle these scenarios. For example, in one scenario, the unified TCI scheme needs to consider the 2-step random access procedure, in which the UE transmits a message A (MsgA) including a physical random access channel (PRACH) and a physical uplink shared channel (PUSCH) and receives a random access response (RAR) from the network entity without a transmission of the message 3 (Msg3) .
[0008] Aspects of the present disclosure address the above-noted and other deficiencies by implementing default beam and pathloss-reference signal (PL-RS) techniques that handle the multiple scenarios. In one example, a UE receives, from a network entity, a configuration configuring a random access (RA) procedure. The configuration also configures TCI states. Accordingly, the UE communicates with the network entity according to the default beam or the default PL-RS that was determined based on a quasi-co-location (QCL) parameter for a first downlink reference signal, or an uplink spatial transmission filter associated with the at least one RA procedure and a pathloss associated with a second downlink reference signal.
[0009] In this manner, the network entity does not need to transmit the beam indication signaling. The network entity and the UE can communicate based on the default beam and PL-RS that can reduce the overhead of beam indication signaling operations. In addition, the network entity and the UE can communicate without a possibility of a beam mismatch situation, which may improve the channel performance for the downlink and uplink before the UE applies the indicated TCI states.
[0010] According to some aspects, a UE receives, from a network entity, control signaling configuring at least one RA procedure from a plurality of RA procedures and configuring a list of TCI states. Prior to an activation of at least one TCI state from the list of TCI states or a UE-initiated beam, the UE communicates with the network entity using at least one of: a default beam or a default PL-RS based on at least one of: a QCL parameter for a first downlink reference signal, or an uplink spatial transmission filter associated with the at least one RA procedure and a pathloss associated with a second downlink reference signal.
[0011] According to some aspects, a network entity transmits, to a UE, control signaling configuring at least one RA procedure from a plurality of RA procedures and configuring a list of TCI states. Prior to an activation of at least one TCI state from the list of TCI states or a UE-initiated beam, the network entity communicates with the UE using at least one of: a default beam or a default PL-RS based on at least one of: a QCL parameter for a first downlink reference signal, or an uplink spatial transmission filter associated with the at least one RA procedure and a pathloss associated with a second downlink reference signal.BRIEF DESCRIPTION OF THE DRAWINGS
[0012] 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.
[0013] FIG. 2 is an example for the uplink (UL) and downlink (DL) beam determination before network entity and UE applying the indicated transmission configuration indication (TCI) state (s) according to an embodiment.
[0014] FIG. 3 is an example is a signaling diagram illustrating communications between a UE and a network entity for Procedure for default beam and pathloss-reference signal (PL-RS) for DL and UL channel according to an embodiment.
[0015] FIG. 4 is an example for the default beam determination based on the synchronization signal block / channel state information-reference signal (SSB / CSI-RS) resource index according to an embodiment.
[0016] FIG. 5 An example for the default beam determination based on the time-domain location of SSB / CSI-RS according to an embodiment.
[0017] FIG. 6 is an example for the default beam determination based on the network entity's configuration according to an embodiment.
[0018] FIG. 7 is an example for the default beam determination based on the UE report according to an embodiment.
[0019] FIG. 8 is an example for the default beam determination based on the time-domain location of message A (MsgA) or message 3 (Msg3) physical uplink shared channel (PUSCH) according to an embodiment.
[0020] FIG. 9 is an example for the default beam determination based on the network entity's configuration according to an embodiment.
[0021] FIG. 10 is an example for the default beam determination based on the UE report according to an embodiment.
[0022] FIG. 11 is a flowchart of a method of wireless communication at a UE according to an embodiment.
[0023] FIG. 12 is a flowchart of a method of wireless communication at a network entity according to an embodiment.
[0024] FIG. 13 is a diagram illustrating a hardware implementation for an example UE apparatus according to some embodiments.
[0025] FIG. 14 is a diagram illustrating a hardware implementation for one or more example network entities according to some embodiments.DETAILED DESCRIPTION
[0026] 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) .
[0027] 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.
[0028] 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.
[0029] 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.
[0030] 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.
[0031] 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. ”
[0032] 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.
[0033] 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) .
[0034] 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.
[0035] 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.
[0036] 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.
[0037] 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 106a can be a secondary node.
[0038] Still referring to FIG. 1, in certain aspects, any of the UEs 102 may include a UE Default Beam Management component 140 configured to receive, from a network entity, control signaling configuring at least one RA procedure from a plurality of RA procedures and configuring a list of TCI states; prior to an activation of at least one TCI state from the list of TCI states or a UE-initiated beam, communicate with the network entity using at least one of: a default beam or a default PL-RS based on at least one of: a QCL parameter for a first downlink reference signal, or an uplink spatial transmission filter associated with the at least one RA procedure and a pathloss associated with a second downlink reference signal.
[0039] In certain aspects, any of the base stations 104 or a network entity of the base stations 104 may include a NE Default Beam Management component 150 configured to transmit, to a UE, control signaling configuring at least one RA procedure from a plurality of RA procedures and configuring a list of TCI states; prior to an activation of at least one TCI state from the list of TCI states or a UE-initiated beam, communicate with the UE using at least one of: a default beam or a default PL-RS based on at least one of: a QCL parameter for a first downlink reference signal, or an uplink spatial transmission filter associated with the at least one RA procedure and a pathloss associated with a second downlink reference signal.
[0040] 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.
[0041] For Multiple-Input Multiple-Output (MIMO) system, the network entity 104 and the UE 102 may maintain a plurality of beams, and a good network entity 104 and UE 102 beam pair can provide a good link budget so as to improve the coverage. Usually, the network entity 104 can configure a list of transmission configuration indication (TCI) states by Radio Resource Control (RRC) signaling for each bandwidth part (BWP) , and transmit a medium access control (MAC) control element (CE) to activate at least one TCI states corresponding to at least one TCI codepoints in a downlink control information (DCI) . If the network entity 104 activates TCI state (s) corresponding to a TCI codepoint, the network entity 104 and UE may communicate based on the TCI state (s) activated by the MAC CE after the action time of the MAC CE. Otherwise, the network entity 104 may further transmit a Downlink Control Information (DCI) indicating the TCI state (s) corresponding to one of the TCI codepoints and the network entity 104 and the UE 102 may communicate based on the TCI state (s) indicated by the TCI codepoint in the DCI after the action time of the DCI.
[0042] FIG. 2 illustrates a diagram 200 of a procedure for determining the uplink (UL) and downlink (DL) beam before the network entity and the UE apply the indicated TCI states.
[0043] Referring to FIG. 2, the UE 102 selects a random access (RA) preamble from a set of predefined preambles. After choosing the preamble, the UE 102 transmits the preamble on message 1 (Msg1) : PRACH 224.
[0044] In response to receiving Msg1, the network entity 104 transmits an RA response called Msg2 226. Msg2 includes information, such as the Time Advance (TA) command for timing adjustment, a Random Access Radio Network Temporary Identifier (RA-RNTI) , and an initial uplink grant for the UE.
[0045] The UE 102 transmits Msg3 228 on the physical uplink shared channel (PUSCH) . Msg3 may include RRC message or just data.
[0046] The network entity 104 transmits RRC reconfiguration 230. The RRC reconfiguration may indicate a list of transmission configuration indication (TCI) states.
[0047] The network entity 104 transmits a TCI indication 232 indicating one or more TCI states from the list of configured TCI states.
[0048] The beam is applied 236 after an acknowledgment (ACK) feedback 234 of the TCI indication 232. The TCI state is applied 236 based on an action time after the ACK feedback associated with the DCI format conveying the TCI state.
[0049] The UE 102 receives the physical downlink control channel (PDCCH) / physical downlink shared channel (PDSCH) and channel state information reference signal (CSI-RS) applying the indicated TCI state based on the beam as the SSB / CSI-RS associated with the PRACH. The UE 102 transmits the PUSCH / physical uplink control channel (PUCCH) and the SRS applying the indicated TCI state based on the beam as indicated in the Msg3.
[0050] When unified TCI state is configured (defined after the initial RRC reconfiguration or RRC reconfiguration with sync procedure which configures at least one TCI states in the TCI list, and before the UE 102 applies the indicated TCI states) , the UE 102 may use the beam, i.e., uplink (UL) transmission (TX) spatial filter, for message 3 (Msg3) , which is scheduled by the RAR, to transmit the PUSCH, PUCCH, and SRS applying the indicated TCI state. The UE 102 may receive the demodulation reference signal (DM-RS) of PDSCH, the DM-RS of PDCCH, and CSI-RS applying the indicated TCI state based on the quasi-co-location (QCL) parameters as the synchronization signal physical broadcast channel (SS / PBCH) block (SSB) or CSI-RS resource associated with the PRACH during the RA procedure. In one example, the corresponding specification is defined in 3GPP TS 38.214 section 5.1.5 as follows:
[0051] After the UE 102 receives an initial higher layer configuration of dl-OrJointTCI-StateList with at least one TCI-State and before the application of an indicated TCI state from the configured TCI states, the UE 102 assumes that the DM-RS of PDSCH and the DM-RS of PDCCH and the CSI-RS applying the indicated TCI state are QCL with the SS / PBCH block the UE 102 identified during the initial access procedure.
[0052] After the UE 102 receives an initial higher layer configuration of dl-OrJointTCI-StateList with at least one TCI-State or ul-TCI-StateList with at least one TCI-UL-State and before application of an indicated TCI state from the configured TCI states, the UE 102 assumes that the UL TX spatial filter, if applicable, for the dynamic-grant and configured-grant based PUSCH and PUCCH, and for the SRS applying the indicated TCI state, is the same as that for a PUSCH transmission scheduled by a RAR UL grant during the initial access procedure.
[0053] After the UE 102 receives a higher layer configuration of dl-OrJointTCI-StateList with at least one TCI-State as part of a Reconfiguration with sync procedure as described in [3GPP TS 38.331] and before applying an indicated TCI state from the configured TCI states, the UE 102 assumes that the DM-RS of PDSCH and the DM-RS of PDCCH, and the CSI-RS applying the indicated TCI state are QCL with the SS / PBCH block or the CSI-RS resource the UE 102 identified during the RA procedure initiated by the Reconfiguration with sync procedure as described in [3GPP TS 38.331] .
[0054] After the UE 102 receives a higher layer configuration of dl-OrJointTCI-StateList with at least one TCI-State or at least one TCI-UL-State as part of a Reconfiguration with sync procedure as described in [3GPP TS 38.331] and before applying an indicated TCI state from the configured TCI states, the UE 102 assumes that the UL TX spatial filter, if applicable, for the dynamic-grant and configured-grant based PUSCH and PUCCH, and for SRS applying the indicated TCI state, is the same as that for a PUSCH transmission scheduled by a RAR UL grant during the RA procedure initiated by the Reconfiguration with sync procedure as described in [3GPP TS 38.331] .
[0055] In addition, if the network entity 104 does not configure the pathloss reference signal (PL-RS) in the RRC signaling or before the UE 102 is provided with dedicated RRC parameters, the UE 102 calculates the pathloss based on the SSB that the UE 102 uses to decode the master information block (MIB) in PCell or the SSB that the UE 102 used to acquire the time and frequency synchronization for an SCell.
[0056] Further, for an uplink channel, e.g., PUCCH or SRS, if the network entity 104 does not configure PL-RS and spatial relation information, e.g., PUCCH-SpatialRelationInfo or SRS-SpatialRelationInfo, the network entity 104 may configure the UE 102 to determine the beam and PL-RS based on the periodic DL RS configured in the TCI state in the control resource set (CORESET) with the lowest CORESET identifier (ID) in the same serving cell as the PUCCH or SRS. In one example, the network entity 104 provides the configuration by RRC parameter enableDefaultBeamPL-ForPUCCH and enableDefaultBeamPL-ForSRS for PUCCH and SRS, respectively.
[0057] When more than one joint or uplink unified TCI states are configured in the initial RRC reconfiguration or RRC reconfiguration with sync procedure, after the UE 102 receives the RRC reconfiguration and before the UE 102 applies the indicated TCI states, the determination of the UE beam and PL-RS is unaddressed with respect to the following scenarios.
[0058] Scenario 1: The RA procedure is based on 2-step RA, where the UE 102 transmits a message A (MsgA) including a PRACH and PUSCH and receives an RAR from the network entity 104 without Msg3 transmission.
[0059] Scenario 2: The default beam for SCell. The SCell and PCell may be in different bands, and it may be impossible for the UE 102 to use the same beam and PL-RS for SCell channels as PCell.
[0060] Scenario 3: The network entity 104 enables the default beam and PL-RS for some UL channels (e.g., PUSCH, PUCCH, and SRS) based on the TCI / QCL for a CORESET, in the RRC reconfiguration.
[0061] Scenario 4: The network entity 104 configures the multiple transmission and reception points (mTRP) operation in the RRC reconfiguration, e.g., the network entity 104 configures a mTRP transmission scheme, e.g., spatial domain multiplexing (SDM) , single frequency network (SFN) , frequency domain multiplexing (FDM) , time domain multiplexing (TDM) , or coherent joint transmission (CJT) for at least one DL or UL channel, or the network entity 104 configures two CORESET pool indexes (or the network entity 104 configures CORESET pool index 1) .
[0062] Scenario 5: The PRACH in the RA procedure may be associated with at least one SSB / CSI-RS resources.
[0063] Scenario 6: The UE 102 may transmit the Msg3 PUSCH based on at least one beam.
[0064] Scenario 7: The network entity 104 does not provide PL-RS and does not enable the default beam and PL-RS for some UL channels, e.g., PUSCH, PUCCH, and SRS, in the RRC configuration.
[0065] Scenario 8: When the UE initiated beam switching is enabled, the UE 102 may apply the UE initiated beam or TCI state instead of the indicated TCI states. After the UE 102 receives the initial RRC reconfiguration or RRC reconfiguration with sync procedure and before the UE 102 applies the UE initiated beam (s) or TCI states.
[0066] With a determination of the default beam and PL-RS technique addressing the above-mentioned scenarios, the network entity 104 does not need to transmit the beam indication signaling. The network entity 104 and UE 102 may communicate based on the default beam and PL-RS, which might reduce the overhead for beam indication signaling. With such technique, the network entity 104 and UE 102 can communicate without a beam mismatch, which might also improve the performance for the DL and UL channels before the UE 102 applies the indicated TCI states.
[0067] In summary, this technique proposes a method for determining the default beam and PL-RS before the UE 102 applies the first indicated TCI states after initial access or after handover (RRC reconfiguration with synchronization) for the above-described scenarios, where the method can also be extended to lower-layer triggered mobility (LTM) without TCI indicated in the cell switching command (CSC) , including: default beam for DL channel / RS reception; default beam and PL-RS for UL channel / RS transmission. It is understood that the techniques described herein may also apply to other scenarios for determining the default beam and PL-RS for communication prior to the UE 102 applying the first indicated TCI states.
[0068] FIG. 3 is a signaling diagram 300 illustrating communications between a UE 102 and a network entity 104 for Procedure for default beam and PL-RS for DL and UL channel 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.
[0069] The DL channel may include at least one of PDSCH, PDCCH, or CSI-RS. The UL channel may include at least one of PUSCH, PUCCH, or SRS. Note that the PUCCH in PCell also indicates the PUCCH in primary secondary cell (PSCell) or PUCCH in PUCCH-SCell (an SCell with PUCCH configured) . A joint TCI indicate a TCI state configured in dl-OrJointqCI-StateList. An activated TCI for a CORESET indicates a TCI indicated by a MAC CE or DCI.
[0070] The network entity 104 and the UE 102 perform random access (RA) procedure 302 based on 2-step random access channel (RACH) procedure or 4-step RACH procedure.
[0071] The UE 102 may receive 304 (network entity 104 may transmit 304) , from a network entity 104, a control signaling for RRC reconfiguration corresponding to the RA procedure 302. In some implementations, the control signaling may be a RRC reconfiguration. In some other implementations, the control signaling may be a CSC that triggers a cell switching with RRC parameters update or reconfiguration.
[0072] The network entity 104 and the UE 102 determine the default beam for at least one DL channel or the default beam and PL-RS for at least one UL channel after the control signaling for RRC reconfiguration and before the network entity 104 and the UE 102 apply the indicated TCI state (s) or UE initiated beam (s) or TCI state (s) . The network entity 104 and the UE 102 may determine the default beam and / or PL-RS based on at least one of the following: the SSB used to decode MIB, the SSB / CSI-RS identified during the RA procedure, the SSB for time / frequency acquisition, the beam for Msg3 or MsgA PUSCH, the DL RS in the TCI for at least one CORESET, or the TCI state (s) from the configured TCI state list.
[0073] After the network entity 104 and the UE 102 apply the indicated TCI state (s) or UE initiated beam (s) or TCI state (s) 308, the network entity 104 and UE may further communicate 310 (e.g., at least one DL channel or at least one UL channel) based on the beam (s) corresponding to the indicated TCI state (s) or UE initiated beam (s) or TCI state (s) .
[0074] In this disclosure, unless specified, a RRC signaling may indicate a RRC reconfiguration message from gNB to UE, or a System Information Block (SIB) , where the SIB can be an existing SIB (e.g., SIB1) or a new SIB (e.g., SIB J, where J is an integer above 21) transmitted by gNB. In some implementations, the network entity 104 may receive the UE capability from a UE or from a core network (e.g., Access and Mobility Management Function (AMF) ) or another network entity.
[0075] FIGs. 1-3 illustrate techniques for default beam and PL-RS for DL and UL channel. FIGs. 4-12 show methods for implementing one or more aspects of FIGs. 1-3. In particular, FIG. 11 shows an implementation by the UE 102 of the one or more aspects of FIGs. 1-3. FIG. 12 shows an implementation by the network entity 104 of the one or more aspects of FIGs. 1-3.
[0076] In an embodiment, when more than one joint or uplink unified TCI states are configured in the initial RRC reconfiguration or RRC reconfiguration with sync procedure corresponding to a 2-step RA procedure, after the UE 102 receives the RRC reconfiguration and before the UE 102 applies the indicated TCI states or before the UE 102 applies the UE initiated beam (s) or TCI state (s) , the UE 102 transmits at least one UL channels based on the UL TX spatial filter for the MsgA PUSCH. The UL channel may include dynamic-grant PUSCH, configured-grant PUSCH, PUCCH and SRS applying the indicated TCI states.
[0077] In one example, after the UE 102 receives an initial higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State or ul-TCI-StateList with more than one TCI-UL-State and before application of an indicated TCI state from the configured TCI states, the UE 102 assumes that the UL TX spatial filter, if applicable, for dynamic-grant and configured-grant based PUSCH and PUCCH, and for SRS applying the indicated TCI state, is the same as that for a PUSCH transmission scheduled by a RAR UL grant or MsgA PUSCH transmission during the initial access procedure.
[0078] In another example, after the UE 102 receives a higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State or more than one TCI-UL-State as part of a Reconfiguration with sync procedure as described in [3GPP TS 38.331] and before applying an indicated TCI state from the configured TCI states, the UE 102 assumes that the UL TX spatial filter, if applicable, for dynamic-grant and configured-grant based PUSCH and PUCCH, and for SRS applying the indicated TCI state, is the same as that for a PUSCH transmission scheduled by a RAR UL grant or MsgA PUSCH transmission during RA procedure initiated by the Reconfiguration with sync procedure as described in [3GPP TS 38.331] .
[0079] In another example, after the UE 102 receives an initial higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State or ul-TCI-StateList with more than one TCI-UL-State and before application of an indicated TCI state from the configured TCI states or application of a UE initiated beam or TCI state, the UE 102 assumes that the UL TX spatial filter, if applicable, for dynamic-grant and configured-grant based PUSCH and PUCCH, and for SRS applying the indicated TCI state, is the same as that for a PUSCH transmission scheduled by a RAR UL grant or MsgA PUSCH transmission during the initial access procedure.
[0080] In another example, after the UE 102 receives a higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State or more than one TCI-UL-State as part of a Reconfiguration with sync procedure as described in [3GPP TS 38.331] and before applying an indicated TCI state from the configured TCI states or application of a UE initiated beam or TCI state, the UE 102 assumes that the UL TX spatial filter, if applicable, for dynamic-grant and configured-grant based PUSCH and PUCCH, and for SRS applying the indicated TCI state, is the same as that for a PUSCH transmission scheduled by a RAR UL grant or MsgA PUSCH transmission during RA procedure initiated by the Reconfiguration with sync procedure as described in [3GPP TS 38.331] .
[0081] In an embodiment, when at least one joint or uplink unified TCI states are configured in the initial RRC reconfiguration or RRC reconfiguration with sync procedure corresponding to a 2-step RA procedure, after the UE 102 receives the RRC reconfiguration and before the UE 102 applies the indicated TCI states or before the UE 102 applies the UE initiated beam (s) or TCI state (s) , the UE 102 transmits at least one UL channels based on the UL TX spatial filter for the MsgA PRACH. The UL channel may include dynamic-grant PUSCH, configured-grant PUSCH, PUCCH, and SRS applying the indicated TCI states.
[0082] In one example, after the UE 102 receives an initial higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State or ul-TCI-StateList with more than one TCI-UL-State and before application of an indicated TCI state from the configured TCI states, the UE 102 assumes that the UL TX spatial filter, if applicable, for dynamic-grant and configured-grant based PUSCH and PUCCH, and for SRS applying the indicated TCI state, is the same as that for a PUSCH transmission scheduled by a RAR UL grant or MsgA PRACH transmission during the initial access procedure.
[0083] In another example, after the UE 102 receives a higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State or more than one TCI-UL-State as part of a Reconfiguration with sync procedure as described in [3GPP TS 38.331] and before applying an indicated TCI state from the configured TCI states, the UE 102 assumes that the UL TX spatial filter, if applicable, for dynamic-grant and configured-grant based PUSCH and PUCCH, and for SRS applying the indicated TCI state, is the same as that for a PUSCH transmission scheduled by a RAR UL grant or MsgA PRACH transmission during RA procedure initiated by the Reconfiguration with sync procedure as described in [3GPP TS 38.331] .
[0084] In another example, after the UE 102 receives an initial higher layer configuration of dl-OrJointTCI-StateList with at least one TCI-State or ul-TCI-StateList with at least one TCI-UL-State and before application of an indicated TCI state from the configured TCI states or application of a UE initiated beam or TCI state, the UE 102 assumes that the UL TX spatial filter, if applicable, for dynamic-grant and configured-grant based PUSCH and PUCCH, and for SRS applying the indicated TCI state, is the same as that for a PUSCH transmission scheduled by a RAR UL grant or MsgA PRACH transmission during the initial access procedure.
[0085] In another example, after the UE 102 receives a higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State or more than one TCI-UL-State as part of a Reconfiguration with sync procedure as described in [3GPP TS 38.331] and before applying an indicated TCI state from the configured TCI states or application of a UE initiated beam or TCI state, the UE 102 assumes that the UL TX spatial filter, if applicable, for dynamic-grant and configured-grant based PUSCH and PUCCH, and for SRS applying the indicated TCI state, is the same as that for a PUSCH transmission scheduled by a RAR UL grant or MsgA PRACH transmission during RA procedure initiated by the Reconfiguration with sync procedure as described in [3GPP TS 38.331] .
[0086] In an embodiment, when at least one joint or uplink unified TCI states are configured in the initial RRC reconfiguration or RRC reconfiguration with sync procedure corresponding to a 2-step RA procedure, after UE 102 receives the RRC reconfiguration and before the UE 102 applies the indicated TCI states or before the UE 102 applies the UE initiated beam (s) or TCI state (s) , the UE 102 transmits at least one UL channels based on the UL TX spatial filter for the first joint or uplink TCI state configured in the TCI state list. The UL channel may include dynamic-grant PUSCH, configured-grant PUSCH, PUCCH and SRS applying the indicated TCI states. In other examples, the UE 102 transmits at least one UL channels based on the UL TX spatial filter for the joint or uplink TCI state with lowest TCI state ID configured in the TCI state list. In yet other examples, the UE 102 transmits at least one UL channels based on the UL TX spatial filter for the first activated joint or uplink TCI state.
[0087] In an embodiment, when at least one joint or uplink unified TCI states are configured in the initial RRC reconfiguration or RRC reconfiguration with sync procedure corresponding to a 2-step RA procedure, after the UE 102 receives the RRC reconfiguration and before the UE applies the indicated TCI states or before the UE 102 applies the UE initiated beam (s) or TCI state (s) , the UE 102 transmits at least one UL channels based on the UL TX spatial filter as the DL reception (RX) spatial filter to receive the SSB / CSI-RS associated with the PRACH. The UL channel may include dynamic-grant PUSCH, configured-grant PUSCH, PUCCH, and SRS applying the indicated TCI states. In other examples, the UE 102 transmits at least one UL channels based on the UL TX spatial filter as the DL reception (RX) spatial filter to receive MsgB RAR reception. In yet other examples, the UE 102 transmits at least one UL channels based on the UL TX spatial filter as the DL RX spatial filter to receive MsgB PDSCH reception.
[0088] In an embodiment, when at least one joint or uplink unified TCI states are configured in the initial RRC reconfiguration or RRC reconfiguration with sync procedure corresponding to a 2-step RA procedure, after the UE 102 receives the RRC reconfiguration and before the UE 102 applies the indicated TCI states or before the UE applies the UE initiated beam (s) or TCI state (s) , the UE 102 transmits at least one UL channels based on the default beam configured by the network entity 104. The network entity 104 may configure the default beam based on one of the beams for MsgA PUSCH, the beam for MsgA PRACH, the first TCI state in the configured TCI state list or the beam for the SSB / CSI-RS identified in the RA procedure. The UL channel may include dynamic-grant PUSCH, configured-grant PUSCH, PUCCH and SRS applying the indicated TCI states.
[0089] Further, the UE 102 may report the UE capability indicating the supported default beam (s) based on at least one of the beams for MsgA PUSCH, the beam for MsgA PRACH, the first TCI state in the configured TCI state list or the beam for the SSB / CSI-RS identified in the RA procedure, or other above-described methods.
[0090] In an embodiment, when at least one joint or downlink / uplink unified TCI states are configured in the initial RRC reconfiguration or RRC reconfiguration with sync procedure, after the UE 102 receives the RRC reconfiguration and before the UE 102 applies the indicated TCI states or before the UE 102 applies the UE initiated beam (s) or TCI state (s) , for SCell, the UE 102 receives at least one DL channels based on the QCL parameters derived from the SSB for time and frequency synchronization, or transmits at least one UL channels based on the UL TX spatial filter as the DL RX spatial filter to receive the SSB for time and frequency synchronization. The DL channel may include PDSCH, PDCCH and CSI-RS applying the indicated TCI states. The UL channel may include dynamic-grant PUSCH, configured-grant PUSCH, PUCCH and SRS applying the indicated TCI states.
[0091] In one example, after the UE 102 receives an initial higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State and before the application of an indicated TCI state from the configured TCI states, the UE 102 assumes that DM-RS of PDSCH and DM-RS of PDCCH and the CSI-RS applying the indicated TCI state are quasi co-located with the SS / PBCH block the UE identified during the initial access procedure or the SS / PBCH block the UE acquired the time and frequency synchronization for a SCell.
[0092] In another example, after a UE 102 receives an initial higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State or ul-TCI-StateList with more than one TCI-UL-State and before application of an indicated TCI state from the configured TCI states, the UE 102 assumes that the UL TX spatial filter, if applicable, for dynamic-grant and configured-grant based PUSCH and PUCCH, and for SRS applying the indicated TCI state, is the same as that for a PUSCH transmission scheduled by a RAR UL grant during the initial access procedure or the DL RX spatial filter for the SS / PBCH block the UE 102 acquired the time and frequency synchronization for a SCell.
[0093] In another example, after a UE 102 receives a higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State as part of a Reconfiguration with sync procedure as described in [3GPP TS 38.331] and before applying an indicated TCI state from the configured TCI states, the UE 102 assumes that DM-RS of PDSCH and DM-RS of PDCCH, and the CSI-RS applying the indicated TCI state are QCL with the SS / PBCH block or the CSI-RS resource the UE 102 identified during the RA procedure initiated by the Reconfiguration with sync procedure as described in [3GPP TS 38.331] or the SS / PBCH block the UE 102 acquired the time and frequency synchronization for a SCell.
[0094] In another example, after the UE 102 receives a higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State or more than one TCI-UL-State as part of a Reconfiguration with sync procedure as described in [3GPP TS 38.331] and before applying an indicated TCI state from the configured TCI states, the UE 102 assumes that the UL TX spatial filter, if applicable, for dynamic-grant and configured-grant based PUSCH and PUCCH, and for SRS applying the indicated TCI state, is the same as that for a PUSCH transmission scheduled by a RAR UL grant during RA procedure initiated by the Reconfiguration with sync procedure as described in [3GPP TS 38.331] or the DL RX spatial filter for the SS / PBCH block the UE acquired the time and frequency synchronization for a SCell.
[0095] In another example, after the UE 102 receives an initial higher layer configuration of dl-OrJointTCI-StateList with at least one TCI-State and before application of an indicated TCI state from the configured TCI states or application of a UE initiated beam or TCI state, the UE 102 assumes that DM-RS of PDSCH and DM-RS of PDCCH and the CSI-RS applying the indicated TCI state are QCL with the SS / PBCH block the UE 102 identified during the initial access procedure or the SS / PBCH block the UE acquired the time and frequency synchronization for a SCell.
[0096] In another example, after the UE 102 receives an initial higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State or ul-TCI-StateList with more than one TCI-UL-State and before application of an indicated TCI state from the configured TCI states or application of a UE initiated beam or TCI state, the UE 102 assumes that the UL TX spatial filter, if applicable, for dynamic-grant and configured-grant based PUSCH and PUCCH, and for SRS applying the indicated TCI state, is the same as that for a PUSCH transmission scheduled by a RAR UL grant during the initial access procedure or the DL RX spatial filter for the SS / PBCH block the UE acquired the time and frequency synchronization for a SCell.
[0097] In another example, after the UE 102 receives a higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State as part of a Reconfiguration with sync procedure as described in [3GPP TS 38.331] and before applying an indicated TCI state from the configured TCI states or application of a UE initiated beam or TCI state, the UE 102 assumes that DM-RS of PDSCH and DM-RS of PDCCH, and the CSI-RS applying the indicated TCI state are quasi co-located with the SS / PBCH block or the CSI-RS resource the UE 102 identified during the RA procedure initiated by the Reconfiguration with sync procedure as described in [3GPP TS 38.331] or the SS / PBCH block the UE 102 acquired the time and frequency synchronization for a SCell.
[0098] In another example, after the UE 102 receives a higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State or more than one TCI-UL-State as part of a Reconfiguration with sync procedure as described in [3GPP TS 38.331] and before applying an indicated TCI state from the configured TCI states or application of a UE initiated beam or TCI state, the UE 102 assumes that the UL TX spatial filter, if applicable, for dynamic-grant and configured-grant based PUSCH and PUCCH, and for SRS applying the indicated TCI state, is the same as that for a PUSCH transmission scheduled by a RAR UL grant during RA procedure initiated by the Reconfiguration with sync procedure as described in [3GPP TS 38.331] or the DL RX spatial filter for the SS / PBCH block the UE 102 acquired the time and frequency synchronization for a SCell.
[0099] In an embodiment, when at least one joint or downlink / uplink unified TCI states are configured in the initial RRC reconfiguration or RRC reconfiguration with sync procedure, after UE receives the RRC reconfiguration and before the UE 102 applies the indicated TCI states or before the UE 102 applies the UE initiated beam (s) or TCI state (s) , for SCell, the UE 102 receives at least one DL channels based on the first joint or downlink TCI state configured in the joint or downlink TCI state list in a BWP (e.g., active BWP, initial BWP or the first BWP) for the SCell, or transmits at least one UL channels based on the UL TX spatial filter for the first joint or uplink TCI state configured in the joint or uplink TCI state list in a BWP (e.g., active BWP, initial BWP or the first BWP) for the SCell. The DL channel may include PDSCH, PDCCH and CSI-RS applying the indicated TCI states. The UL channel may include dynamic-grant PUSCH, configured-grant PUSCH, PUCCH and SRS applying the indicated TCI states.
[0100] In an embodiment, when at least one joint or downlink / uplink unified TCI states are configured in the initial RRC reconfiguration or RRC reconfiguration with sync procedure, after UE receives the RRC reconfiguration and before the UE a102 applies the indicated TCI states or before the UE 102 applies the UE initiated beam (s) or TCI state (s) , for SCell, the UE receives at least one DL channels or transmits at least one UL channels based on a configured default beam. The DL channel may include PDSCH, PDCCH and CSI-RS applying the indicated TCI states. The UL channel may include dynamic-grant PUSCH, configured-grant PUSCH, PUCCH and SRS applying the indicated TCI states.
[0101] The network entity 104 may configure the default beam based on one of the beams for SSB for time and frequency synchronization, the first TCI state in the configured TCI state list or the beam for the SSB / CSI-RS or MsgA / Msg3 PUSCH identified in the RA procedure. The network entity 104 may transmit the configuration by RRC signaling or MAC CE, e.g., MAC CE activating the SCell.
[0102] Further, in some implementations, the UE 102 may report the UE capability indicating the supported default beam (s) based on at least one of the beams for SSB for time and frequency synchronization, the first TCI state in the configured TCI state list or the beam for the SSB / CSI-RS or MsgA / Msg3 PUSCH identified in the RA procedure.
[0103] In an embodiment, when at least one joint or uplink unified TCI states are configured and default beam and PL-RS is enabled for at least one UL channel (e.g., enableDefaultBeamPL-ForPUSCH0-0, enableDefaultBeamPL-ForPUCCH and enableDefaultBeamPL-ForSRS) in the initial RRC reconfiguration or RRC reconfiguration with sync procedure, after UE 102 receives the RRC reconfiguration and before the UE 102 applies the indicated TCI states or before the UE 102 applies the UE initiated beam (s) or TCI state (s) , the UE 102 transmits at least one UL channels based on the UL TX spatial filter as the DL RX spatial filter for the DL RS in a TCI state for a CORESET with lowest ID in the active BWP. The UL channel may include dynamic-grant PUSCH, configured-grant PUSCH, PUCCH and SRS applying the indicated TCI states. In one example, the TCI state refers to the indicated TCI states or UE initiated beam (s) or TCI state (s) , whichever is applied for the CORESET. In another one example, when determining CORESET with lowest ID, the UE only considers / selects CORESET (s) applying the indicated TCI states. In another one example, when default beam and PL-RS is enabled for at least one UL channel in the initial RRC reconfiguration or RRC reconfiguration with sync procedure, the network entity 104 shall ensure the CORESET with lowest ID in the active BWP applies the indicated TCI state.
[0104] In one example, after the UE 102 receives an initial higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State or ul-TCI-StateList with more than one TCI-UL-State and before application of an indicated TCI state from the configured TCI states, the UE 102 assumes that the UL TX spatial filter, if applicable, for dynamic-grant and configured-grant based PUSCH (if enableDefaultBeamPL-ForPUSCH0-0 is not provided) and PUCCH (if enableDefaultBeamPL-ForPUCCH is not provided) , and for SRS (if enableDefaultBeamPL-ForSRS is not provided) applying the indicated TCI state, is the same as that for a PUSCH transmission scheduled by a RAR UL grant during the initial access procedure.
[0105] In another example, after the UE 102 receives a higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State or more than one TCf-UL-State as part of a Reconfiguration with sync procedure as described in [3GPP TS 38.331] and before applying an indicated TCI state from the configured TCI states, the UE 102 assumes that the UL TX spatial filter, if applicable, for dynamic-grant and configured-grant based PUSCH (if enableDefaultBeamPL-ForPUSCH0-0 is not provided) and PUCCH (if enableDefaultBeamPL-ForPUCCH is not provided) , and for SRS (if enableDefaultBeamPL-ForSRS is not provided) applying the indicated TCI state, is the same as that for a PUSCH transmission scheduled by a RAR UL grant during RA procedure initiated by the Reconfiguration with sync procedure as described in [3GPP TS 38.331] .
[0106] In another example, after the UE 102 receives an initial higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State or ul-TCI-StateList with more than one TCI-UL-State and before application of an indicated TCI state from the configured TCI states or application of a UE initiated beam or TCI state, the UE 102 assumes that the UL TX spatial filter, if applicable, for dynamic-grant and configured-grant based PUSCH (if enableDefaultBeamPL-ForPUSCH0-0 is not provided) and PUCCH (if enableDefaultBeamPL-ForPUCCH is not provided) , and for SRS (if enableDefaultBeamPL-ForSRS is not provided) applying the indicated TCI state, is the same as that for a PUSCH transmission scheduled by a RAR UL grant during the initial access procedure.
[0107] In another example, after the UE 102 receives a higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State or more than one TCI-UL-State as part of a Reconfiguration with sync procedure as described in [3GPP TS 38.331] and before applying an indicated TCI state from the configured TCI states or application of a UE initiated beam or TCI state, the UE 102 assumes that the UL TX spatial filter, if applicable, for dynamic-grant and configured-grant based PUSCH (if enableDefaultBeamPL-ForPUSCH0-0 is not provided) and PUCCH (if enableDefaultBeamPL-ForPUCCH is not provided) , and for SRS (if enableDefaultBeamPL-ForSRS is not provided) applying the indicated TCI state, is the same as that for a PUSCH transmission scheduled by a RAR UL grant during RA procedure initiated by the Reconfiguration with sync procedure as described in [3GPP TS 38.331] .
[0108] In another example, if the UE 102 is not provided pathlossReferenceRSs, and is not provided PUCCH-SpatialRelationInfo, and is provided enableDefaultBeamPL-ForPUCCH, and is not indicated with a TCI-State or TCI-UL-State, and is not provided coresetPoolIndex value of 1 for any CORESET, or is provided coresetPoolIndex value of 1 for all CORESETs, in ControlResourceSet and no codepoint of a TCI field, if any, in a DCI format of any search space set maps to two TCI states, the UE 102 determines a PL-RS resource index q_d for the PUCCH power control providing a periodic RS resource configured with qcl-Type set to ‘typeD’ in the TCI state or the QCL assumption of a CORESET with the lowest index in the active DL BWP of the primary cell. If the CORESET has two activated TCI states, the UE determines the RS resource index q_d based on the first activated TCI state. For a PUCCH transmission over multiple slots, a same q_d applies to the PUCCH transmission in each of the multiple slots.
[0109] In another example, if a UE 102 is not provided pathlossReferenceRSs in PUCCH-PowerControl, is provided enableDefaultBeamPL-ForPUCCH, and is not provided PUCCH-SpatialRelationInfo, and is not indicated with a TCI-State or TCI-UL-State, and is not provided coresetPoolIndex value of 1 for any CORESET, or is provided coresetPoolIndex value of 1 for all CORESETs, in ControlResourceSet and no codepoint of a TCI field, if any, in a DCI format of any search space set maps to two TCI states a spatial setting for a PUCCH transmission from the UE 102 is same as a spatial setting for PDCCH receptions by the UE in the CORESET with the lowest ID on the active DL BWP of the PCell and, if the CORESET has two activated TCI states, the UE 102 determines the spatial setting for the PUCCH transmission based on the first activated TCI state. For a PUCCH transmission over multiple slots, a same spatial setting applies to the PUCCH transmission in each of the multiple slots.
[0110] In another example, if the UE is not provided pathlossReferenceRS or SRS-PathlossReferenceRS-Id, is not provided spatialRelationInfo, and is provided enableDefaultBeamPL-ForSRS, and is not indicated with a TCI-State or TCI-UL-State, and is not provided coresetPoolIndex value of 1 for any CORESET, or is provided coresetPoolIndex value of 1 for all CORESETs, in ControlResourceSet and no codepoint of a TCI field, if any, in a DCI format of any search space set maps to two TCI states, the UE 102 determines a PL-RS resource index qd for the SRS power control providing a periodic RS resource configured with qcl-Type set to ‘typeD’ in the TCI state or the QCL assumption of a CORESET with the lowest index in the active DL BWP, if CORESETs are provided in the active DL BWP of serving cell c. If the CORESET has two activated TCI states, the UE 102 determines the RS resource index qd based on the first TCI state. the active PDSCH TCI state with lowest ID in the active DL BWP, if CORESETs are not provided in the active DL BWP of serving cell c.
[0111] In another example, when the higher layer parameter enableDefaultBeamPL-ForSRS is set ‘enabled’ , and if the higher layer parameter spatialRelationInfo for the SRS resource, except for the SRS resource with the higher layer parameter usage in SRS-ResourceSet set to ‘beamManagement’ or for the SRS resource with the higher layer parameter usage in SRS-ResourceSet set to ‘nonCodebook’ with configuration of associatedCSI-RS or for the SRS resource configured by the higher layer parameter SRS-PosResourceSet, is not configured in frequency range (FR) 2 (e.g., frequency range above 7GHz or 28GHz) and if the UE 102 is not configured with higher layer parameter (s) pathlossReferenceRS, and if the UE 102 is not configured with different values of coresetPoolIndex in ControlResourceSets, and is not provided with at least one TCI codepoint mapped with two TCI states, and if the UE 102 is not indicated with a TCI-State or TCI-UL-State for the SRS resource, the UE 102 shall transmit the target SRS resource in an active UL BWP of a CC, (i) according to the spatial relation, if applicable, with a reference to the RS configured with qcl-Type set to ‘typeD’ corresponding to the QCL assumption of the CORESET with the lowest controlResourceSetId in the active DL BWP in the component carrier (CC) . If the CORESET is activated with two TCI states, sfnSchemePdcch is configured and the UE 102 supports sfn-DefaultUL-BeamSetup-r17, UE 102 shall use the first TCI state as the QCL assumption; (ii) according to the spatial relation, if applicable, with a reference to the RS configured with qcl-Type set to ′typeD′ in the activated TCI state with the lowest ID applicable to PDSCH in the active DL BWP of the CC if the UE 102 is not configured with any CORESET in the active DL BWP of the CC.
[0112] In an embodiment, when at least one joint or uplink unified TCI states are configured and default beam and PL-RS is enabled for at least one UL channel (e.g., enableDefaultBeamPL-ForPUSCH0-0, enableDefaultBeamPL-ForPUCCH and enableDefaultBeamPL-ForSRS) in the initial RRC reconfiguration or RRC reconfiguration with sync procedure, after the UE 102 receives the RRC reconfiguration and before the UE 102 applies the indicated TCI states or before the UE 102 applies the UE initiated beam (s) or TCI state (s) , the UE 102 transmits at least one UL channels based on the UL TX spatial filter as the MsgA PUSCH or Msg3 PUSCH. The UL channel may include dynamic-grant PUSCH, configured-grant PUSCH, PUCCH and SRS applying the indicated TCI states.
[0113] In some implementations, the UE 102 only applies the enabled default beam or PL-RS when unified TCI state is not configured by the network entity 104. In some examples, the network entity 104 only configures / indicates the UE 102 to enable or use default beam or PL-RS when the network entity 104 does not configure unified TCI state for the UE 102. In some other implementations, the network entity 104 refrains from enabling the default beam (e.g., configuring enableDefaultBeamPL-ForPUSCH0-0, enableDefaultBeamPL-ForPUCCH or enableDefaultBeamPL-ForSRS) and configuring the unified TCI state for the same serving cell or BWP. Thus, the UE 102 does not expect the network entity 104 enable the default beam (e.g., configuring enableDefaultBeamPL-ForPUSCH0-0, enableDefaultBeamPL-ForPUCCH or enableDefaultBeamPL-ForSRS) and configure the unified TCI state for the same serving cell or BWP.
[0114] In one example, if the UE 102 is not provided pathlossReferenceRSs, and is not provided PUCCH-SpatialRelationInfo, and is provided enableDefaultBeamPL-ForPUCCH, and is not provided TCI-State in dl-OrJointTCI-StateList or TCI-UL-State, and is not provided coresetPoolIndex value of 1 for any CORESET, or is provided coresetPoolIndex value of 1 for all CORESETs, in ControlResourceSet and no codepoint of a TCI field, if any, in a DCI format of any search space set maps to two TCI states the UE 102 determines a PL-RS resource index qd for the PUCCH power control providing a periodic RS resource configured with qcl-Type set to ‘typeD’ in the TCI state or the QCL assumption of a CORESET with the lowest index in the active DL BWP of the primary cell. If the CORESET has two activated TCI states, the UE 102 determines the RS resource index qd based on the first activated TCI state. For a PUCCH transmission over multiple slots, a same qd applies to the PUCCH transmission in each of the multiple slots.
[0115] In another example, if a UE 102 is not provided pathlossReferenceRSs in PUCCH-PowerControl, is provided enableDefaultBeamPL-ForPUCCH, and is not provided PUCCH-SpatialRelationInfo, and is not provided TCI-State in dl-OrJointTCI-StateList or TCI-UL-State, and is not provided coresetPoolIndex value of 1 for any CORESET, or is provided coresetPoolIndex value of 1 for all CORESETs, in ControlResourceSet and no codepoint of a TCI field, if any, in a DCI format of any search space set maps to two TCI states a spatial setting for a PUCCH transmission from the UE 102 is same as a spatial setting for PDCCH receptions by the UE in the CORESET with the lowest ID on the active DL BWP of the PCell and, if the CORESET has two activated TCI states, the UE determines the spatial setting for the PUCCH transmission based on the first TCI state. For a PUCCH transmission over multiple slots, a same spatial setting applies to the PUCCH transmission in each of the multiple slots.
[0116] In another example, if the UE 102 is not provided pathlossReferenceRS or SRS-PathlossReferenceRS-Id, is not provided spatialRelationInfo, and is provided enableDefaultBeamPL-ForSRS, and is not provided TCI-State in dl-OrJointTCI-StateList or TCI-UL-State, and is not provided coresetPoolIndex value of 1 for any CORESET, or is provided coresetPoolIndex value of 1 for all CORESETs, in ControlResourceSet and no codepoint of a TCI field, if any, in a DCI format of any search space set maps to two TCI states, the UE determines a PL-RS resource index qd for the SRS power control providing a periodic RS resource configured with qcl-Type set to ‘typeD’ in (i) the TCI state or the QCL assumption of a CORESET with the lowest index in the active DL BWP, if CORESETs are provided in the active DL BWP of serving cell c. If the CORESET has two activated TCI states, the UE determines the RS resource index qd based on the first TCI state; (ii) the active PDSCH TCI state with lowest ID in the active DL BWP, if CORESETs are not provided in the active DL BWP of serving cell c.
[0117] In another example, when the higher layer parameter enableDefaultBeamPL-ForSRS is set ‘enabled’ , and if the higher layer parameter spatialRelationInfo for the SRS resource, except for the SRS resource with the higher layer parameter usage in SRS-ResourceSet set to ‘beamManagement’ or for the SRS resource with the higher layer parameter usage in SRS-ResourceSet set to ‘nonCodebook’ with configuration of associatedCSI-RS or for the SRS resource configured by the higher layer parameter SRS-PosResourceSet, is not configured in frequency range (FR) 2 (e.g., frequency range above 7GHz or 28GHz) and if the UE 102 is not configured with higher layer parameter (s) pathlossReferenceRS, and if the UE 102 is not configured with different values of coresetPoolIndex in ControlResourceSets, and is not provided at least one TCI codepoint mapped with two TCI states, and if the UE 102 is not provided TCI-State in dl-OrJointTCI-StateList or TCI-UL-State, the UE 102 shall transmit the target SRS resource in an active UL BWP of a CC according to the spatial relation, if applicable, with a reference to the RS configured with qcl-Type set to ′typeD′ corresponding to the QCL assumption of the CORESET with the lowest controlResourceSetId in the active DL BWP in the compontent carrier (CC) . If the CORESET is activated with two TCI states, sfnSchemePdcch is configured and the UE supports sfn-DefaultUL-BeamSetup-r17, UE shall use the first TCI state as the QCL assumption according to the spatial relation, if applicable, with a reference to the RS configured with qcl-Type set to ′typeD′ in the activated TCI state with the lowest ID applicable to PDSCH in the active DL BWP of the CC if the UE is not configured with any CORESET in the active DL BWP of the CC.
[0118] In an embodiment, when more than one joint or uplink unified TCI states and mTRP operation for at least one DL channels or UL channels are configured in the initial RRC reconfiguration or RRC reconfiguration with sync procedure, after UE receives the RRC reconfiguration and before the UE applies the indicated TCI states or before the UE applies the UE initiated beam (s) or TCI state (s) , the UE receives at least one DL channel (s) or transmits the UL channel (s) based on more than one default beams.
[0119] In some implementations, the network entity 104 configures the mTRP operation for an UL channel or DL channel by configuring at least one CORESET pool indexes, or by configuring mTRP scheme (e.g., SDM / FDM / TDM / SFN) for the UL or DL channel or configuring linkage for two search spaces for mTRP PDCCH. The UL channel may include PUSCH and PUCCH. The DL channel may include PDSCH and PDCCH.
[0120] In some implementations, the network entity 104 and UE 102 may determine the more than one default beams based on the N (N>1, e.g., N=2) TCI states configured by RRC reconfiguration, e.g., the first N TCI states in the configured joint or uplink or downlink TCI states lists, or N TCI states configured by the network entity 104. For the channel with mTRP operation configured, the UE 102 applies the N TCI states. For channel without mTRP operation configured, the UE 102 may apply one of the N TCI states, which may be configured by the RRC signaling, e.g., which indicates whether the UE 102 should apply the first or second TCI state, or the UE 102 may apply the SSB / CSI-RS identified for RA procedure for QCL determination for the DL channel or the MsgA or Msg3 PUSCH beam for the UL TX spatial filter for the UL channel.
[0121] In some implementations, the network entity 104 and UE 102 may determine one default beam for the channel corresponding to a CORESET pool index. The network entity 104 and UE 102 may determine the default beam for a CORESET pool based on the DL RS in the TCI state or QCL determination corresponding to a CORESET in the CORESET pool, e.g., CORESET with lowest ID among the CORESETs in the CORESET pool. If there are two DL RSs configured in the TCI state for the CORESETs, the network entity 104 and UE 102 determine the default beam based on the DL RS used for QCL-TypeD indication. If there are more than one TCI states (e.g., two TCI states) indicated for the CORESETs, the network entity 104 and UE 102 may determine the default beam based on a pre-defined TCI state, e.g., the first indicated TCI state, or a TCI state among the more than one TCI states configured by the network entity 104.
[0122] In an embodiment, when at least one joint or uplink unified TCI states and mTRP operation for at least one DL channels or UL channels are configured in the initial RRC reconfiguration or RRC reconfiguration with sync procedure, after the UE 102 receives the RRC reconfiguration and before the UE 102 applies the indicated TCI states or before the UE 102 applies the UE initiated beam (s) or TCI state (s) , the network entity 104 refrains from scheduling the at least one DL channels or UL channels with mTRP operation. The network entity 104 may schedule the at least one DL channels or UL channels based on single TRP operation. Thus, the UE 102 may not expect the network entity 104 schedules the at least one DL channels or UL channels with mTRP operation after UE 102 receives the initial RRC reconfiguration or RRC reconfiguration with sync procedure and before the UE applies the indicated TCI states or before the UE applies the UE initiated beam (s) or TCI state (s) .
[0123] In some other implementations, the network entity 104 may refrain from scheduling the at least one DL channels or UL channels with mTRP operation that requires the UE to perform simultaneous transmission and / or simultaneous reception with two different TCI states or QCL assumptions, e.g., SDM scheme, SFN scheme, FDM scheme, or channels from different CORESET pools that overlap in time domain.
[0124] FIG. 4 illustrates a diagram 400 of an example for the default beam determination based on the SSB / CSI-RS resource index (e.g., SSB / CSI-RS 1, SSB / CSI-RS 2, ..., SSB / CSI-RS K) according to an embodiment.
[0125] The UE 102 transmits a PRACH (also referred to as Msg1 or RA preamble) associated with SSB / CSI-RS 1 424A and transmits another PRACH (also referred to as Msg1 or RA preamble) associated with SSB / CSI-RS K 424B. In response to receiving Msg1, the network entity 104 transmits an RA response (RAR) referred to as Msg2 426. The UE 102 transmits Msg3 428 on the PUSCH. The network entity 104 transmits RRC Reconfiguration 430 that indicates a list of TCI states (configured TCI states) . The network entity 104 transmits a TCI indication (e.g., MAC-CE or DCI) 432 to indicate at least one TCI state from the list of TCI states. The UE 102 transmits ACK 434 for the TCI indication 432. The UE 102 applies the beam corresponding to the at least one TCI state based on action time after ACK transmission.
[0126] In some implementations, after the UE 102 receives the RRC reconfiguration 430 and before the UE 102 applies the indicated TCI states 436 or before the UE 102 applies the UE initiated beam (s) or TCI state (s) , the default beam may be determined based on the SSB / CSI-RS resource index (e.g., associated with PRACH transmission 424A, 424B) . For example, when more than one joint unified TCI states are configured in the initial RRC reconfiguration 430 or RRC reconfiguration 430 with sync procedure corresponding to the RA procedure with more than one SSBs / CSI-RSs identified, the UE 102 receives at least one DL channel (s) based one of the SSBs / CSI-RSs identified during the RA procedure. In some other implementations, the SSB / CSI-RS for default beam determination may be predefined or configured by the network entity or reported by the UE 102.
[0127] In some implementations, the network entity 104 and the UE 102 may determine the default beam based on the SSB / CSI-RS resource index. For example, the network entity 104 and the UE 102 determines the default beam based on the lowest or highest SSB / CSI-RS resource index of the SSBs / CSI-RSs identified during the RA procedure. Referring to FIG. 4, the network entity 104 and the UE 102 determines the default beam based on SSB / CSI-RS with a resource index of 1 associated with PRACH transmission 424A (e.g., based on the lowest SSB / CSI-RS resource index) . In other implementations, the network entity and UE determines the default beam based on SSB / CSI-RS with resource index of K associated with PRACH transmission 424B (e.g., based on the highest SSB / CSI-RS resource index) .
[0128] In one example, after the UE 102 receives an initial higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State and before application of an indicated TCI state from the configured TCI states, the UE 102 assumes that the DM-RS of PDSCH and the DM-RS of PDCCH and the CSI-RS applying the indicated TCI state are quasi co-located with the SS / PBCH block the UE 102 identified during the initial access procedure and if more than one SS / PBCH blocks are identified, the one with the lowest SS / PBCH index among identified SS / PBCH blocks is selected.
[0129] In another example, after a UE 102 receives a higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State as part of a Reconfiguration with sync procedure as described in [3GPP TS 38.331] and before applying an indicated TCI state from the configured TCI states, the UE 102 assumes that DM-RS of PDSCH and DM-RS of PDCCH, and the CSI-RS applying the indicated TCI state are quasi co-located with the SS / PBCH block or the CSI-RS resource the UE identified during the RA procedure initiated by the Reconfiguration with sync procedure as described in [3GPP TS 38.331] and if more than one SS / PBCH blocks or CSI-RS resources are identified, the one with the lowest SS / PBCH or CSI-RS resource index among identified SS / PBCH blocks or CSI-RS resources is selected.
[0130] FIG. 5 illustrates a diagram 500 of an example for the default beam determination based on the time-domain location of SSB / CSI-RS according to an embodiment.
[0131] The UE 102 transmits a PRACH (also referred to as Msg1 or RA preamble) associated with SSB / CSI-RS 1 524A and transmits another PRACH (also referred to as Msg1 or RA preamble) associated with SSB / CSI-RS K 524B. In response to receiving Msg1, the network entity 104 transmits an RA response (RAR) referred to as Msg2 526. The UE 102 transmits Msg3 528 on the PUSCH.
[0132] The network entity 104 transmits RRC Reconfiguration 530 that indicates a list of TCI states (configured TCI states) . The network entity 104 transmits a TCI indication (e.g., MAC-CE or DCI) 532 to indicate at least one TCI state from the list of TCI states. The UE 102 transmits ACK 534 for the TCI indication 532. The UE 102 applies the beam corresponding to the at least one TCI state based on action time after ACK transmission. The TCI state is applied 536 based on an action time after the ACK feedback 534 associated with the DCI format conveying the TCI state.
[0133] In some implementations, the network entity 104 and the UE 102 may determine default beam based on the time-domain location of the SSB / CSI-RS (e.g., associated with PRACH transmission 524A, 524B) (e.g., the one starting first or ending last) . Referring to FIG. 5, the network entity 104 and the UE 102 determines the default beam based on the SSB / CSI-RS that ends last (e.g., SSB / CSI-RS K associated with PRACH transmission 524B) . In other implementations, the network and UE determines the default beam based on the SSB / CSI-RS that starts first (e.g., SSB / CSI-RS 1 associated with PRACH transmission 524A) .
[0134] In one example, after the UE 102 receives an initial higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State and before application of an indicated TCI state from the configured TCI states, the UE 102 assumes that the DM-RS of PDSCH and DM-RS of PDCCH and the CSI-RS applying the indicated TCI state are QCL with the SS / PBCH block the UE identified during the initial access procedure. If more than one SS / PBCH blocks are identified, the one that ends later is selected.
[0135] In another example, after a UE receives a higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State as part of a Reconfiguration with sync procedure as described in [3GPP TS 38.331] and before applying an indicated TCI state from the configured TCI states, the UE assumes that DM-RS of PDSCH and DM-RS of PDCCH. The UE also assumes the CSI-RS applying the indicated TCI state are quasi co-located with the SS / PBCH block or the CSI-RS resource the UE identified during the RA procedure initiated by the Reconfiguration with sync procedure as described in [3GPP TS 38.331] . If more than one SS / PBCH blocks or CSI-RS resources are identified, the one that ends later is selected.
[0136] FIG. 6 illustrates a diagram 600 of an example for the default beam determination based on the network entity-configuration according to an embodiment.
[0137] The UE 102 transmits a PRACH (also referred to as Msg1 or RA preamble) associated with SSB / CSI-RS 1 624A and transmits another PRACH (also referred to as Msg1 or RA preamble) associated with SSB / CSI-RS K 624B. In response to receiving Msg1, the network entity 104 transmits an RA response (RAR) referred to as Msg2 626. The network entity 104 transmits RRC Reconfiguration 630 that indicates a list of TCI states (configured TCI states) . The RRC Reconfiguration 630 also indicates a default beam based on SSB / CSI-RS x (so the UE 102 uses this default beam to communicate prior to action time of 636) . The network entity 104 transmits a TCI indication (e.g., MAC-CE or DCI) 632 to indicate at least one TCI state from the list of TCI states. The UE 102 transmits ACK 634 for the TCI indication 632. The UE 102 applies the beam corresponding to the at least one TCI state based on action time after ACK transmission. The TCI state is applied 636 based on an action time after the ACK feedback 634 associated with the DCI format conveying the TCI state.
[0138] In some implementations, the network entity 104 and the UE 102 may determine the SSB / CSI-RS for the default beam determination based on network entity configuration. In one example, the network entity 104 transmits the RRC reconfiguration 630 that configures or indicates the SSB / CSI-RS resource index (es) among the identified SSB / CSI-RS resource for default beam determination. Referring to FIG. 6, the network entity indicates the SSB / CSI-RS resource index x (e.g., SSB / CSI-RS resource index 1 associated with PRACH transmission 624A or SSB / CSI-RS resource index K associated with PRACH transmission 624B) in the RRC reconfiguration 630 for determining the default beam. The network entity 104 may transmit the configuration / indication by RRC reconfiguration, MAC-CE or DCI. In one example, the network entity 104 transmits the configuration by the RAR 626. In another example, the network entity 104 transmits the configuration / indication by the DCI scheduling the UL or DL channel. Alternatively, the network entity 104 and the UE 102 determine the SSB / CSI-RS based on the location (e.g., time and frequency domain location) of the RAR or the message 4 (Msg4) from the network entity 104 in response to the Msg3. The associated SSB / CSI-RS for each candidate location of the Msg2 or Msg4 may be configured by the network entity 104 or predefined. In one example, the network entity 104 and the UE 102 determine the SSB / CSI-RS based on the SSB / CSI-RS that is QCLed with the Msg2 or Msg4.
[0139] In one example, after the UE 102 receives an initial higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State and before application of an indicated TCI state from the configured TCI states, the UE 102 assumes that the DM-RS of PDSCH and the DM-RS of PDCCH and the CSI-RS applying the indicated TCI state are quasi co-located with the SS / PBCH block. The UE 102 identified the SS / PBCH block during the initial access procedure. If more than one SS / PBCH blocks are identified, the SS / PBCH configured by ssbIndexForDefaultBeam is selected.
[0140] In another example, after the UE 102 receives a higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State as part of a Reconfiguration with sync procedure as described in [3GPP TS 38.331] and before applying an indicated TCI state from the configured TCI states, the UE 102 assumes that DM-RS of PDSCH and DM-RS of PDCCH, and the CSI-RS applying the indicated TCI state are quasi co-located with the SS / PBCH block or the CSI-RS resource. The UE 102 identified the SS / PBCH block or the CSI-RS resource during the RA procedure initiated by the Reconfiguration with sync procedure as described in [3GPP TS 38.331] . If more than one SS / PBCH blocks or CSI-RS resources are identified, the SS / PBCH blocks, or CSI-RS resources configured by ssbriCriForDefaultBeam is selected.
[0141] FIG. 7 illustrates a diagram 700 of an example for the default beam determination based on the UE report according to an embodiment.
[0142] The UE 102 transmits a PRACH (also referred to as Msg1 or RA preamble) associated with SSB / CSI-RS 1 724A and transmits another PRACH (also referred to as Msg1 or RA preamble) associated with SSB / CSI-RS K 724B. In response to receiving Msg1, the network entity 104 transmits an RA response (RAR) referred to as Msg2 726. The UE 102 transmits a PUSCH (Msg3) 728 using a beam associated with SSB / CSI-RS resource index x. Msg3 728 also indicates default beam (based on SSB / CSI-RS x) the UE 102 will use prior to action time of 736. The network entity 104 transmits RRC Reconfiguration 730 that indicates a list of TCI states (configured TCI states) . The network entity 104 transmits a TCI indication (e.g., MAC-CE or DCI) 732 to indicate at least one TCI state from the list of TCI states. The UE 102 transmits ACK 734 for the TCI indication 732. The UE 102 applies the beam corresponding to the at least one TCI state based on action time after ACK transmission. The TCI state is applied 736 based on an action time after the ACK feedback 734 associated with the DCI format conveying the TCI state.
[0143] In some implementations, the network entity 104 and the UE 102 determine the SSB / CSI-RS for the default beam determination based on the UE report from the UE 102. Referring to FIG. 7, the network entity 104 and the UE 102 determine the SSB / CSI-RS for determining the default beam based on the UE report. In one example, the UE 102 reports the SSB / CSI-RS resource index (es) (e.g., SSB / CSI-RS resource index 1 associated with PRACH transmission 724A, SSB / CSI-RS resource index K associated with PRACH transmission 724B) among the identified SSB / CSI-RS resource for default beam determination. In some implementations, the UE 102 may transmit the report by RRC message 730 or MAC CE or uplink control information. In one example, the UE 102 transmits the report by the Msg3. In another example, the UE 102 transmits the report by the RRC reconfiguration complete message. Alternatively, the network entity 104 and the UE 102 determine the SSB / CSI-RS based on the Msg3 location (time and / or frequency domain resource) . The association between each Msg3 location and SSB or CSI-RS may be configured by the network entity 104 or predefined.
[0144] In one example, after the UE 102 receives an initial higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State and before application of an indicated TCI state from the configured TCI states, the UE 102 assumes that the DM-RS of PDSCH and the DM-RS of PDCCH and the CSI-RS applying the indicated TCI state are quasi co-located with the SS / PBCH block. The UE 102 identified the SS / PBCH block during the initial access procedure. If more than one SS / PBCH blocks are identified, the SS / PBCH block reported by the UE 102 is selected.
[0145] In another example, after a UE 102 receives a higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State as part of a Reconfiguration with sync procedure as described in [3GPP TS 38.331] and before applying an indicated TCI state from the configured TCI states, the UE 102 assumes that the DM-RS of PDSCH and the DM-RS of PDCCH, and the CSI-RS applying the indicated TCI state are quasi co-located with the SS / PBCH block or the CSI-RS resource. The UE 102 identified the SS / PBCH block or the CSI-RS resource during the RA procedure initiated by the Reconfiguration with sync procedure as described in [3GPP TS 38.331] . If more than one SS / PBCH blocks or CSI-RS resources are identified, the SS / PBCH block, or the CSI-RS resource reported by the UE is selected.
[0146] In an embodiment, when more than one joint unified TCI states configured in the initial RRC reconfiguration or RRC reconfiguration with sync procedure corresponding to RA procedure with more than one SSBs / CSI-RSs identified, after the UE 102 receives the RRC reconfiguration and before the UE 102 applies the indicated TCI states or before the UE 102 applies the UE initiated beam (s) or TCI state (s) , the UE 102 receives at least one DL channel (s) based one of the configured TCI state. In some implementations, the TCI state may be predefined, for example, the first TCI state configured in the TCI state list, or configured by the network entity 104. In some other implementations, the TCI state may be the joint TCI state with the lowest TCI state ID configured in the TCI state list. In yet some other implementations, the TCI state may be the first activated TCI state. The network entity 104 may transmit the configuration by RRC reconfiguration or MAC CE or DCI. In one example, the network entity 104 transmits the configuration by the RAR. In another example, the network entity 104 transmits the configuration by the DCI scheduling the UL or DL channel.
[0147] FIG. 8 illustrates a diagram 800 of an example for the default beam determination based on the time-domain location of MsgA or Msg3 PUSCH according to an embodiment.
[0148] Referring to FIG. 8, after choosing a RA preamble based on measurements of the SSBs / CSI-RSs, the UE 102 transmits the RS preamble referred to as message 1 (Msg1) on PRACH. For example, the UE 102 transmits a PRACH (also referred to as Msg1 or RA preamble) associated with SSB / CSI-RS 1 824A and transmits another PRACH (also referred to as Msg1 or RA preamble) associated with SSB / CSI-RS K 824B.
[0149] In response to receiving Msg1 824A, 824B, the network entity 104 transmits an RA response (RAR) referred to as Msg2 826. The UE 102 transmits a PUSCH (Msg3) 828A using a beam associated with SSB / CSI-RS resource index 1 and another PUSCH (Msg3) 828B using a beam associated with SSB / CSI-RS resource index K. In some implementations, the UE 102 may use a similar technique when transmitting multiple MsgA PUSCHs for the 2-step RA procedure. The network entity 104 transmits RRC Reconfiguration 830 that indicates a list of TCI states (configured TCI states) . The network entity 104 transmits a TCI indication (e.g., MAC-CE or DCI) 832 to indicate at least one TCI state from the list of TCI states. The UE 102 transmits ACK 834 for the TCI indication 832. The UE 102 applies the beam corresponding to the at least one TCI state based on action time after ACK transmission. The TCI state is applied 836 based on an action time after the ACK feedback 834 associated with the DCI format conveying the TCI state.
[0150] In some implementations, when more than one joint or uplink unified TCI states configured in the initial RRC reconfiguration or RRC reconfiguration with sync procedure corresponding to RA procedure with Msg3 PUSCH or MsgA PUSCH with more than one UL TX spatial filters applied, after the UE 102 receives the RRC reconfiguration and before the UE 102 applies the indicated TCI states or before the UE applies the UE initiated beam (s) or TCI state (s) , the UE 102 transmits at least one UL channel (s) based one of the UL TX spatial filters for the Msg3 PUSCH or MsgA PUSCH during the RA procedure. In some implementations, the transmission occasion for the Msg3 PUSCH or MsgA PUSCH for default beam determination may be predefined or configured by the network entity 104 or reported by the UE 102.
[0151] In some implementations, the UE 102 may determine the default beam for the UL channel (s) based on the time-domain location of the Msg3 PUSCH or MsgA PUSCH, for example, the one starting or ending first or last. Referring to FIG. 8, the UE 102 determines the default beam for the UL channel (s) based on the time-domain location of the Msg3 PUSCH 828B that ends last. In other implementations, the UE 102 determines the default beam for the UL channel (s) based on the time-domain location of Msg3 PUSCH 828A that starts first.
[0152] In one example, after the UE 102 receives an initial higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State or ul-TCI-StateList with more than one TCI-UL-State and before application of an indicated TCI state from the configured TCI states, the UE 102 assumes that the UL TX spatial filter, if applicable, for dynamic-grant and configured-grant based PUSCH and PUCCH, and for SRS applying the indicated TCI state, is the same as that for a PUSCH transmission scheduled by a RAR UL grant during the initial access procedure. If the UE 102 transmits the PUSCH with more than one UL TX spatial filters, the UL TX spatial filter for the PUSCH that ends later is selected.
[0153] In another example, after the UE 102 receives a higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State or more than one TCI-UL-State as part of a Reconfiguration with sync procedure as described in [3GPP TS 38.331] and before applying an indicated TCI state from the configured TCI states, the UE 102 assumes that the UL TX spatial filter, if applicable, for dynamic-grant and configured-grant based PUSCH and PUCCH, and for SRS applying the indicated TCI state, is the same as that for a PUSCH transmission scheduled by a RAR UL grant during RA procedure initiated by the Reconfiguration with sync procedure as described in [3GPP TS 38.331] . If the UE 102 transmits the PUSCH with more than one UL TX spatial filters, the UL TX spatial filter for the PUSCH that ends later is selected.
[0154] FIG. 9 illustrates a diagram 900 of an example for the default beam determination based on the network entity’s configuration according to an embodiment.
[0155] The UE 102 transmits a PRACH (also referred to as Msg1 or RA preamble) associated with SSB / CSI-RS 1 924A and transmits another PRACH (also referred to as Msg1 or RA preamble) associated with SSB / CSI-RS K 924B. In response to receiving Msg1, the network entity 104 transmits an RA response (RAR) referred to as Msg2 926. The UE 102 transmits a PUSCH (Msg3) 928A using a beam associated with SSB / CSI-RS resource index 1 and another PUSCH (Msg3) 928B using a beam associated with SSB / CSI-RS resource index K. In some implementations, the UE 102 may use a similar technique when transmitting multiple MsgA PUSCHs for the 2-step RA procedure.
[0156] The network entity 104 transmits RRC Reconfiguration 930 that indicates a list of TCI states (configured TCI states) . The RRC Reconfiguration 930 also indicates a default beam based on SSB / CSI-RS x (so the UE 102 uses this default beam to communicate prior to action time of 936) . The network entity 104 transmits a TCI indication (e.g., MAC-CE or DCI) 932 to indicate at least one TCI state from the list of TCI states. The UE 102 transmits ACK 934 for the TCI indication 932. The UE 102 applies the beam corresponding to the at least one TCI state based on action time after ACK transmission. The TCI state is applied 936 based on an action time after the ACK feedback 934 associated with the DCI format conveying the TCI state.
[0157] In some implementations, the network entity 104 and UE determine default beam based on configuration from the network entity 104. In one example, the network entity 104 configures the SSB / CSI-RS resource indexes (e.g., 924A, 924B) among the SSB / CSI-RS resources associated with the Msg3 or MsgA PUSCH for default beam determination. Referring to FIG. 9, network entity 104 configures the SSB / CSI-RS resource index (e.g., 924A) associated with the Msg3 PUSCH (e.g., 928A) for determining the default beam. The network entity 104 may transmit the configuration / indication by RRC reconfiguration or MAC CE or DCI. In one example, the network entity 104 transmits the configuration / indication by the RAR. In another example, the network entity 104 transmits the configuration by the DCI scheduling the UL or DL channel. Figure 11 illustrates one example for the default beam determination based on the network entity’s configuration.
[0158] In one example, after the UE receives an initial higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State or ul-TCI-StateList with more than one TCI-UL-State and before application of an indicated TCI state from the configured TCI states, the UE 102 assumes that the UL TX spatial filter, if applicable, for dynamic-grant and configured-grant based PUSCH and PUCCH, and for SRS applying the indicated TCI state, is the same as that for a PUSCH transmission scheduled by a RAR UL grant during the initial access procedure. If the UE 102 transmits the PUSCH with more than one UL TX spatial filters, the UL TX spatial filter for the PUSCH associated with the SS / PBCH block configured by ssbIndexForDefaultBeam is selected.
[0159] In another example, after the UE 102 receives a higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State or more than one TCI-UL-State as part of a Reconfiguration with sync procedure as described in [3GPP TS 38.331] and before applying an indicated TCI state from the configured TCI states, the UE 102 assumes that the UL TX spatial filter, if applicable, for dynamic-grant and configured-grant based PUSCH and PUCCH, and for SRS applying the indicated TCI state, is the same as that for a PUSCH transmission scheduled by a RAR UL grant during RA procedure initiated by the Reconfiguration with sync procedure as described in [3GPP TS 38.331] . If the UE 102 transmits the PUSCH with more than one UL TX spatial filters, the one for the PUSCH associated with the SS / PBCH block or CSI-RS resource configured by ssbriCriForDefaultBeam is selected.
[0160] FIG. 10 illustrates a diagram 1000 of example for the default beam determination based on the UE report according to an embodiment.
[0161] Referring to FIG. 10, after choosing a RA preamble based on measurements of the SSBs / CSI-RSs, the UE 102 transmits the RS preamble referred to as message 1 (Msg1) on PRACH. For example, the UE 102 transmits a PRACH (also referred to as Msg1 or RA preamble) associated with SSB / CSI-RS 1 1024A and transmits another PRACH (also referred to as Msg1 or RA preamble) associated with SSB / CSI-RS K 1024B.
[0162] In response to receiving Msg1 1024A, 1024B, the network entity 104 transmits an RA response (RAR) referred to as Msg2 1026. The UE 102 transmits a PUSCH (Msg3) 1028A using a beam associated with SSB / CSI-RS resource index 1 and another PUSCH (Msg3) 1028B using a beam associated with SSB / CSI-RS resource index K. In some implementations, the UE 102 may use a similar technique when transmitting multiple MsgA PUSCHs for the 2-step RA procedure. The network entity 104 transmits a TCI indication (e.g., MAC-CE or DCI) 1032 to indicate at least one TCI state from the list of TCI states. The UE 102 transmits ACK 1034 for the TCI indication 1032. The UE 102 applies the beam corresponding to the at least one TCI state based on action time after ACK transmission. The TCI state is applied 1036 based on an action time after the ACK feedback 1034 associated with the DCI format conveying the TCI state.
[0163] The network entity 104 transmits RRC reconfiguration 1030A and the UE 102 transmits RRC reconfiguration complete 1030B. The network entity 104 transmits RRC Reconfiguration 1030A that indicates a list of TCI states (configured TCI states) . The RRC reconfiguration complete message 1030B includes a UE report on which default beam the UE 102 will use (based on SSB / CSI-RS x for default beam) .
[0164] In some implementations, the network entity 104 and the UE 102 may determine the default beam based on the UE report from the UE 102. In one example, the UE 102 reports the SSB / CSI-RS resource indexes (e.g., 1024A, 1024B) among the SSB / CSI-RS resources associated with the MsgA or Msg3 PUSCH for the default beam determination. The UE 102 may transmit the UE report by RRC message or MAC CE or uplink control information. In one example, the UE 102 transmits the UE report by the RRC reconfiguration complete message. Referring to FIG. 10, the network entity 104 and the UE 102 determine the default beam based on the UE report transmitted via the RRC reconfiguration complete 1030B.
[0165] In one example, after the UE 102 receives an initial higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State or ul-TCI-StateList with more than one TCI-UL-State and before application of an indicated TCI state from the configured TCI states, the UE 102 assumes that the UL TX spatial filter, if applicable, for dynamic-grant and configured-grant based PUSCH and PUCCH, and for SRS applying the indicated TCI state, is the same as that for a PUSCH transmission scheduled by a RAR UL grant during the initial access procedure. If the UE 102 transmits the PUSCH with more than one UL TX spatial filters, the UL TX spatial filter for the PUSCH associated with the SS / PBCH block reported by the UE is selected.
[0166] In another example, after the UE receives a higher layer configuration of dl-OrJointTCI-StateList with more than one TCI-State or more than one TCI-UL-State as part of a Reconfiguration with sync procedure as described in [3GPP TS 38.331] and before applying an indicated TCI state from the configured TCI states, the UE 102 assumes that the UL TX spatial filter, if applicable, for dynamic-grant and configured-grant based PUSCH and PUCCH, and for SRS applying the indicated TCI state, is the same as that for a PUSCH transmission scheduled by a RAR UL grant during RA procedure initiated by the Reconfiguration with sync procedure as described in [3GPP TS 38.331] . If the UE 102 transmits the PUSCH with more than one UL TX spatial filters, the one for the PUSCH associated with the SS / PBCH block or CSI-RS resource reported by the UE is selected.
[0167] In some implementations, the network entity 104 and the UE 102 may determine the default beam based on one of the SSBs / CSI-RSs that the UE identified during RA procedure. The network entity 104 and the UE 102 may determine the SSB / CSI-RS based on at least one of the following: The SSB / CSI-RS resource index; the time-domain location of the SSB / CSI-RS; whether the SSB / CSI-RS is used for time and frequency synchronization by the UE 102 or not.
[0168] In an embodiment, when more than one joint or uplink unified TCI states configured in the initial RRC reconfiguration or RRC reconfiguration with sync procedure corresponding to RA procedure with more than Msg3 PUSCH or MsgA PUSCH with more than one UL TX spatial filters applied, after UE receives the RRC reconfiguration and before the UE applies the indicated TCI states or before the UE 102 applies the UE initiated beam (s) or TCI state (s) , the UE 102 transmits at least one UL channel (s) based one of configured TCI states. The TCI state may be predefined, for example, the first TCI state configured in the TCI state list, or configured by the network entity 104. In other cases, the TCI state may be the joint TCI state or uplink TCI state with lowest TCI state ID configured in the TCI state list. In yet other cases, the TCI state may be the first activated TCI state. The network entity 104 may transmit the configuration by RRC reconfiguration or MAC CE or DCI. In one example, the network entity 104 transmits the configuration by the RAR. In another example, the network entity 104 transmits the configuration by the DCI scheduling the UL or DL channel.
[0169] In an embodiment, if the network entity 104 does not configure the PL-RS for PUCCH or PUSCH, and the network entity 104 disables the default beam / PL-RS, for example, the network entity 104 does not provide enableDefaultBeamPL-ForPUCCH and enableDefaultBeamPL-ForSRS, the UE 102 determines the pathloss based the SSB that the UE 102 decodes MIB for PCell or the SSB that the UE 102 used to acquire time and frequency synchronization for SCell.
[0170] In an example, for PUCCH, if the UE 102 is not provided pathlossReferenceRSs and enableDefaultBeamPL-ForPUCCH or before the UE 102 is provided dedicated higher layer parameters, the UE 102 calculates the pathloss PLb, f, c (qd) using a RS resource obtained from an SS / PBCH block with same SS / PBCH block index as the one the UE 102 uses to obtain MIB, or using the SS / PBCH block the UE 102 acquired the time and frequency synchronization for a SCell.
[0171] In another example, for SRS, if the UE 102 is not provided pathlossReferenceRS or SRS-PathlossReferenceRS-Id and enableDefaultBeamPL-ForSRS, or before the UE is provided dedicated higher layer parameters, the UE 102 calculates the pathloss PLb, f, c (qd) using a RS resource obtained from an SS / PBCH block with same SS / PBCH block index as the one the UE 102 uses to obtain MIB, or using the SS / PBCH block the UE acquired the time and frequency synchronization for a SCell.
[0172] In an example, for PUCCH, if the UE 102 is not provided pathlossReferenceRSs and enableDefaultBeamPL-ForPUCCH and if UE reports support of default pathloss RS for PUCCH, the UE calculates the pathloss PLb, f, c (qd) using a RS resource obtained from an SS / PBCH block with same SS / PBCH block index as the one the UE 102 uses to obtain MIB, or using the SS / PBCH block the UE 102 acquired the time and frequency synchronization for a SCell.
[0173] In another example, for SRS, if the UE 102 is not provided pathlossReferenceRS or SRS-PathlossReferenceRS-Id and enableDefaultBeamPL-ForSRS, and if the UE reports support of default pathloss RS for SRS, the UE 102 calculates the pathloss PLb, f, c (qd) using a RS resource obtained from an SS / PBCH block with same SS / PBCH block index as the one the UE uses to obtain MIB, or using the SS / PBCH block the UE acquired the time and frequency synchronization for a SCell.
[0174] FIG. 11 illustrates a flowchart 1100 of a method of wireless communication at a UE. With reference to FIGs. 1-10, the method may be performed by the UE 102.
[0175] In embodiments, the UE 102 receives 1104, from the network entity 104, control signaling configuring at least one RA procedure from a plurality of RA procedures and configuring a list of TCI states. In some implementations, the control signaling may include a first RRC message for configuring RA procedure and a second RRC message for configuring the list of TCI states. In some other implementations, the control signaling may include a single RRC message. In some implementations, at least one RA procedure includes a 2-step RA procedure. The plurality of RA procedures includes the 2-step RA procedure and the 4-step RA procedure. For example, referring to FIG. 3, the UE 102 receives 304 control signaling for RRC reconfiguration. In some implementations, the UE 102 may perform, with the network entity 104, an RA procedure configured in the control signaling.
[0176] In embodiments, prior to an activation of at least one TCI state from the list of TCI states or a UE-initiated beam, the UE 102 communicates 1110 with the network entity (104) using at least one of: a default beam or a default pathloss-reference signal (PL-RS) based 1106 on at least one of: a quasi-co-location (QCL) parameter for a first downlink reference signal, or an uplink spatial transmission filter associated with the at least one RA procedure and a pathloss associated with a second downlink reference signal. For example, referring to FIG. 3, the UE communicates 310 with the network entity 104 on at least one DL channel (s) based on default beam (s) or at least one UL channel (s) based on default beam and default PL-RS in PCell and / or SCell based 306 on at least one of: the SSB used to decode MIB, the SSB / CSI-RS identified during the RA procedure, the SSB for time / frequency acquisition, the beam for Msg3 or MsgA PUSCH, the DL RS in the TCI for at least one CORESET, or the TCI state (s) from the configured TCI state list.
[0177] In embodiments, the UE 102 may switch 1108 from the default beam to the UE-initiated beam or a TCI state indicated by the network entity 104. For example, referring to FIG. 3, the UE 102 switches 308 from the default beam to TCI indication from the network entity 104 or UE initiated beam switching.
[0178] In embodiments, the UE 102 may communicate 1110, with the network entity 104, based on the UE-initiated beam or the indicated TCI state. For example, referring to FIG. 3, the UE 102 communicates 310 with the network entity 104 using the at least one DL channel (s) or the at least one UL channel (s) based on beam (s) indicated by the network entity 104 or initiated by the UE 102.
[0179] FIG. 11 describes a method from a UE-side of a wireless communication link, whereas FIG. 12 describes a method from a network-side of the wireless communication link.
[0180] FIG. 12 is a flowchart 1200 of a method of wireless communication at a network entity. With reference to FIGs. 1-10, 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.
[0181] In embodiments, the network entity 104 transmits 1204, to the UE 102, control signaling configuring at least one RA procedure from a plurality of RA procedures and configuring a list of TCI states. In some implementations, the control signaling may include a first RRC message for configuring RA procedure and a second RRC message for configuring the list of TCI states. In some other implementations, the control signaling may include a single RRC message. In some implementations, at least one RA procedure includes a 2-step RA procedure. The plurality of RA procedures includes the 2-step RA procedure and the 4-step RA procedure. For example, referring to FIG. 3, the network entity 104 transmits 304 control signaling for RRC reconfiguration. In some implementations, the network entity 104 may perform, with the UE 102, an RA procedure configured in the control signaling.
[0182] In embodiments, prior to an activation of at least one TCI state from the list of TCI states or a UE-initiated beam, the network entity 104 communicates 1206 with the UE 102 using at least one of: a default beam or a default pathloss-reference signal (PL-RS) based on at least one of: a quasi-co-location (QCL) parameter for a first downlink reference signal, or an uplink spatial transmission filter associated with the at least one RA procedure and a pathloss associated with a second downlink reference signal. For example, referring to FIG. 3, the network entity 104 communicates 310 with the UE 102 on at least one DL channel (s) based on default beam (s) or at least one UL channel (s) based on default beam and default PL-RS in PCell and / or SCell based 306 on at least one of: the SSB used to decode MIB, the SSB / CSI-RS identified during the RA procedure, the SSB for time / frequency acquisition, the beam for Msg3 or MsgA PUSCH, the DL RS in the TCI for at least one CORESET, or the TCI state (s) from the configured TCI state list.
[0183] In embodiments, the network entity 104 may switch 1208 from the default beam to the UE-initiated beam or a TCI state indicated by the network entity 104. For example, referring to FIG. 3, the network entity 104 switches 308 from the default beam to TCI indication from the network entity 104 or UE initiated beam switching.
[0184] In embodiments, the network entity 104 may communicate 1210, with the UE 102, based on the UE-initiated beam or the indicated TCI state. For example, referring to FIG. 3, the network entity 104 communicates with the UE 102 using the at least one DL channel (s) or the at least one UL channel (s) based on beam (s) indicated by the network entity 104 or initiated by the UE 102.
[0185] A UE apparatus 1302, as described in FIG. 13, may perform the method of flowchart 1100. The one or more network entities 104, as described in FIG. 14, may perform the method of flowchart 1200.
[0186] FIG. 13 is a diagram 1300 illustrating an example of a hardware implementation for a UE apparatus 1302. The UE apparatus 1302 may be the UE 102, a component of the UE 102, or may implement UE functionality. The UE apparatus 1302 may include an application processor 1306, which may have on-chip memory 1306’. In examples, the application processor 1306 may be coupled to a secure digital (SD) card 1308 and / or a display 1310. The application processor 1306 may also be coupled to a sensor (s) module 1312, a power supply 1314, an additional module of memory 1316, a camera 1318, and / or other related components.
[0187] The UE apparatus 1302 may further include a wireless baseband processor 1326, which may be referred to as a modem. The wireless baseband processor 1326 may have on-chip memory 1326′. Along with, and similar to, the application processor 1306, the wireless baseband processor 1326 may also be coupled to the sensor (s) module 1312, the power supply 1314, the additional module of memory 1316, the camera 1318, and / or other related components. The wireless baseband processor 1326 may be additionally coupled to one or more subscriber identity module (SIM) card (s) 1320 and / or one or more transceivers 1330 (e.g., wireless RF transceivers) .
[0188] Within the one or more transceivers 1330, the UE apparatus 1302 may include a Bluetooth module 1332, a WLAN module 1334, an SPS module 1336 (e.g., GNSS module) , and / or a cellular module 1338. The Bluetooth module 1332, the WLAN module 1334, the SPS module 1336, and the cellular module 1338 may each include an on-chip transceiver (TRX) , or in some cases, just a transmitter (TX) or just a receiver (RX) . The Bluetooth module 1332, the WLAN module 1334, the SPS module 1336, and the cellular module 1338 may each include dedicated antennas and / or utilize antennas 1340 for communication with one or more other nodes. For example, the UE apparatus 1302 can communicate through the transceiver (s) 1330 via the antennas 1340 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.
[0189] The wireless baseband processor 1326 and the application processor 1306 may each include a computer-readable medium / memory 1326′, 1306′, respectively. The additional module of memory 1316 may also be considered a computer-readable medium / memory. Each computer-readable medium / memory 1326′, 1306′, 1316 may be non-transitory. The wireless baseband processor 1326 and the application processor 1306 may each be responsible for general processing, including execution of software stored on the computer-readable medium / memory 1326′, 1306′, 1316. The software, when executed by the wireless baseband processor 1326 / application processor 1306, causes the wireless baseband processor 1326 / application processor 1306 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 1326 / application processor 1306 when executing the software. The wireless baseband processor 1326 / application processor 1306 may be a component of the UE 102. The UE apparatus 1302 may be a processor chip (e.g., modem and / or application) and include just the wireless baseband processor 1326 and / or the application processor 1306. In other examples, the UE apparatus 1302 may be the entire UE 102 and include the additional modules of the apparatus 1302.
[0190] As discussed in FIG. 1 and implemented with respect to FIG. 11, the UE Default Beam Management component 140 is configured to receive, from a network entity, control signaling configuring at least one RA procedure from a plurality of RA procedures and configuring a list of TCI states; prior to an activation of at least one TCI state from the list of TCI states or a UE-initiated beam, communicate with the network entity using at least one of: a default beam or a default PL-RS based on at least one of: a QCL parameter for a first downlink reference signal, or an uplink spatial transmission filter associated with the at least one RA procedure and a pathloss associated with a second downlink reference signal.
[0191] The UE Default Beam Management component 140 may be within the application processor 1306 (e.g., at 140a) , the wireless baseband processor 1326 (e.g., at 140b) , or both the application processor 1306 and the wireless baseband processor 1326. The UE Default Beam Management 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.
[0192] FIG. 14 is a diagram 1400 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 1446, which may have on-chip memory 1446′. In some aspects, the CU 110 may further include an additional module of memory 1456 and / or a communications interface 1448, both of which may be coupled to the CU processor 1446. The CU 110 can communicate with the DU 108 through a midhaul link 162, such as an F1 interface between the communications interface 1448 of the CU 110 and a communications interface 1428 of the DU 108.
[0193] The DU 108 may include a DU processor 1426, which may have on-chip memory 1426′. In some aspects, the DU 108 may further include an additional module of memory 1436 and / or the communications interface 1428, both of which may be coupled to the DU processor 1426. The DU 108 can communicate with the RU 106 through a fronthaul link 160 between the communications interface 1428 of the DU 108 and a communications interface 1408 of the RU 106.
[0194] The RU 106 may include an RU processor 1406, which may have on-chip memory 1406′. In some aspects, the RU 106 may further include an additional module of memory 1416, the communications interface 1408, and one or more transceivers 1430, all of which may be coupled to the RU processor 1406. The RU 106 may further include antennas 1440, which may be coupled to the one or more transceivers 1430, such that the RU 106 can communicate through the one or more transceivers 1430 via the antennas 1440 with the UE 102.
[0195] The on-chip memory 1406′, 1426′, 1446′ and the additional modules of memory 1416, 1436, 1456 may each be considered a computer-readable medium / memory. Each computer-readable medium / memory may be non-transitory. Each of the processors 1406, 1426, 1446 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) 1406, 1426, 1446 causes the processor (s) 1406, 1426, 1446 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) 1406, 1426, 1446 when executing the software. In examples, the NE Default Beam Management 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.
[0196] As discussed in FIG. 1 and implemented with respect to FIG. 12, the NE Default Beam Management component 150 is configured to transmit, to a UE, control signaling configuring at least one RA procedure from a plurality of RA procedures and configuring a list of TCI states; prior to an activation of at least one TCI state from the list of TCI states or a UE-initiated beam, communicate with the UE using at least one of: a default beam or a default PL-RS based on at least one of: a QCL parameter for a first downlink reference signal, or an uplink spatial transmission filter associated with the at least one RA procedure and a pathloss associated with a second downlink reference signal.
[0197] The NE Default Beam Management component 150 may be within one or more processors of the one or more network entities 104, such as the RU processor 1406 (e.g., at 150a) , the DU processor 1426 (e.g., at 150b) , and / or the CU processor 1446 (e.g., at 150c) . The NE Default Beam Management 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 1406, 1426, 1446 configured to perform the stated processes / algorithm, stored within a computer-readable medium for implementation by the one or more processors 1406, 1426, 1446, or a combination thereof.
[0198] 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.
[0199] 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.
[0200] 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.
[0201] 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.
[0202] 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.
[0203] 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.
[0204] 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.
[0205] 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.
[0206] 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.
[0207] 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 “a widget” . Hence, the recitation “a widget” may be interpreted as “at least one widget” or, similarly, interpreted as “one or more widgets” .
[0208] 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.
[0209] 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.
[0210] 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.
[0211] The following examples are illustrative only and may be combined with other examples or teachings described herein, without limitation.
[0212] Example 1 is a method of wireless communication at a UE, including: receiving, from a network entity, control signaling configuring at least one RA procedure from a plurality of RA procedures and configuring a list of TCI states; and prior to an activation of at least one TCI state from the list of TCI states or a UE-initiated beam, communicating with the network entity using at least one of: a default beam or a default PL-RS based on at least one of:
[0213] a QCL parameter for a first downlink reference signal, or
[0214] an uplink spatial transmission filter associated with the at least one RA procedure and a pathloss associated with a second downlink reference signal.
[0215] Example 2 may be combined with Example 1 and further includes that the at least one RA procedure is a 2-step RA procedure, and further includes that the communicating using the default beam is based on at least one of:
[0216] a MsgA PUSCH, a MsgA PRACH, the at least one TCI state from the list of TCI states, a SSB or CSI-RS associated with the at least one RA procedure, or a configuration for the default beam.
[0217] Example 3 may be combined with Example 1 and further includes that the default beam is for a SCell, and wherein the communicating using the default beam is based on at least one of: a first SSB for a time and frequency synchronization, a second SSB for the at least one TCI state from the list of TCI states, or a configuration for the default beam.
[0218] Example 4 may be combined with Example 1 and further includes that the default beam is a network-enabled default beam, and wherein the communicating using the default beam is based on the default beam being at least one of: activated by the network entity, or indicated by the network entity during the at least one RA procedure.
[0219] Example 5 may be combined with Example 1 and further includes that the control signaling indicates mTRPs, and wherein the default beam is included in a plurality of default beams associated with a plurality of TCI states.
[0220] Example 6 may be combined with Example 1 and further includes that the at least RA procedure is associated with a plurality of SSB or CSI-RS resources, and wherein the communicating using the default beam is based on at least one of: an SSB or CSI-RS resource index, a time-domain location of the SSB or CSI-RS, the control signaling, a UE report for the SSB or CSI-RS, or the at least one TCI state from the list of TCI states.
[0221] Example 7 may be combined with Example 1 and further includes that the at least RA procedure includes a plurality of beams associated with a MsgA or a Msg3, and wherein the communicating using the default beam is based on at least one of: a time-domain location of a MsgA PUSCH or a Msg3 PUSCH, the control signaling, a UE report for a SSB or CSI-RS, the SSB or CSI-RS and a predefined protocol, or the at least one TCI state from the list of TCI states.
[0222] Example 8 may be combined with Example 1 and further includes that the control signaling omits a configuration for the default PL-RS and the at least one of: the default beam or the default PL-RS is disabled, a pathloss being based on a SSB used for decoding a MIB or acquiring a time and frequency synchronization.
[0223] Example 9 may be combined with any Examples 1-8 and further includes switching (308) from the default beam to the UE-initiated beam or a TCI state indicated by the network entity.
[0224] Example 10 is a method of wireless communication at a network entity, including: transmitting, to a UE, control signaling configuring at least one RA procedure from a plurality of RA procedures and configuring a list of TCI states; and prior to an activation of at least one TCI state from the list of TCI states or a UE-initiated beam, communicating with the UE at least one of: a default beam or a default PL-RS based on at least one of: a QCL parameter for a first downlink reference signal, or an uplink spatial transmission filter associated with the at least one RA procedure and a pathloss associated with a second downlink reference signal.
[0225] Example 11 may be combined with Example 10 and further includes that the at least one RA procedure is a 2-step RA procedure, and further includes that the communicating using the default beam is based on at least one of: a MsgA PUSCH, a MsgA PRACH, the at least one TCI state from the list of TCI states,
[0226] a SSB or CSI-RS associated with the at least one RA procedure, or a configuration for the default beam.
[0227] Example 12 may be combined with Example 10 and further includes that the default beam is for a SCell, and wherein the communicating using the default beam is based on at least one of: a first SSB for a time and frequency synchronization, a second SSB for the at least one TCI state from the list of TCI states, or a configuration for the default beam.
[0228] Example 13 may be combined with Example 10 and further includes that the default beam is a network-enabled default beam, and wherein the communicating using the default beam is based on the default beam being at least one of: activated by the network entity, or indicated by the network entity during the at least one RA procedure.
[0229] Example 14 may be combined with Example 10 and further includes that the control signaling indicates mTRPs, and wherein the default beam is included in a plurality of default beams associated with a plurality of TCI states.
[0230] Example 15 may be combined with Example 10 and further includes that the control signaling indicates mTRPs, and further includes that the default beam is excluded in a plurality of default beams associated with a plurality of TCI states.
[0231] Example 16 may be combined with Example 10 and further includes that the at least RA procedure is associated with a plurality of SSB or CSI-RS resources, and wherein the communicating using the default beam is based on at least one of: an SSB or CSI-RS resource index, a time-domain location of the SSB or CSI-RS, the control signaling, a UE report for the SSB or CSI-RS, or the at least one TCI state from the list of TCI states.
[0232] Example 17 may be combined with Example 10 and further includes that the at least RA procedure includes a plurality of beams associated with a MsgA or a Msg3, and wherein the communicating using the default beam is based on at least one of: a time-domain location of a MsgA PUSCH or a Msg3 PUSCH, the control signaling, a UE report for a SSB or CSI-RS, the SSB or CSI-RS and a predefined protocol, or the at least one TCI state from the list of TCI states.
[0233] Example 18 may be combined with Example 10 and further includes that the control signaling omits a configuration for the default PL-RS and the at least one of: the default beam or the default PL-RS is disabled, a pathloss being based on the SSB used for decoding a MIB or acquiring a time and frequency synchronization.
[0234] Example 20 may be combined with any Examples 10-18 and further includes switching from the default beam to the UE-initiated beam or a TCI state indicated by the network entity.
[0235] Example 21 is an apparatus for wireless communication for implementing a method as in any of examples 1-20.
[0236] Example 22 is an apparatus for wireless communication including means for implementing a method as in any of examples 1-20.
[0237] Example 23 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 1-20.
Claims
1.A method of wireless communication at a user equipment (UE) (102) , comprising:receiving (304) , from a network entity (104) , control signaling configuring at least one random access (RA) procedure from a plurality of RA procedures and configuring a list of transmission configuration indicator (TCI) states; andprior to an activation of at least one TCI state from the list of TCI states or a UE-initiated beam, communicating (306) with the network entity (104) using at least one of: a default beam or a default pathloss-reference signal (PL-RS) based on at least one of:a quasi-co-location (QCL) parameter for a first downlink reference signal, oran uplink spatial transmission filter associated with the at least one RA procedure and a pathloss associated with a second downlink reference signal.2.The method of claim 1, wherein the at least one RA procedure is a 2-step RA procedure, and wherein the communicating (306) using the default beam is based on at least one of:a message A (MsgA) physical uplink shared channel (PUSCH) ,a MsgA physical random access channel (PRACH) ,the at least one TCI state from the list of TCI states,a synchronization signal block (SSB) or channel state information reference signal (CSI-RS) associated with the at least one RA procedure, ora configuration for the default beam.3.The method of claim 1, wherein the default beam is for a secondary cell (SCell) , and wherein the communicating (306) using the default beam is based on at least one of:a first synchronization signal block (SSB) for a time and frequency synchronization,a second SSB for the at least one TCI state from the list of TCI states, ora configuration for the default beam.4.The method of claim 1, wherein the default beam is a network-enabled default beam, and wherein the communicating (306) using the default beam is based on the default beam being at least one of:activated by the network entity (104) , orindicated by the network entity (104) during the at least one RA procedure.5.The method of claim 1, wherein the control signaling indicates multiple transmission-reception points (mTRPs) , and wherein the default beam is included in a plurality of default beams associated with a plurality of TCI states.6.The method of claim 1, wherein the at least RA procedure is associated with a plurality of synchronization signal block (SSB) or channel state information reference signal (CSI-RS) resources, and wherein the communicating (306) using the default beam is based on at least one of:an SSB or CSI-RS resource index,a time-domain location of the SSB or CSI-RS,the control signaling,a UE report for the SSB or CSI-RS, orthe at least one TCI state from the list of TCI states.7.The method of claim 1, wherein the at least RA procedure includes a plurality of beams associated with a MsgA or a message 3 (Msg3) , and wherein the communicating (306) using the default beam is based on at least one of:a time-domain location of a MsgA physical uplink shared channel (PUSCH) or a Msg3 PUSCH,the control signaling,a UE report for a synchronization signal block (SSB) or channel state information reference signal (CSI-RS) ,the SSB or CSI-RS and a predefined protocol, orthe at least one TCI state from the list of TCI states.8.The method of claim 1, wherein the control signaling omits a configuration for the default PL-RS and the at least one of: the default beam or the default PL-RS is disabled, a pathloss being based on a synchronization signal block (SSB) used for decoding a master information block (MIB) or acquiring a time and frequency synchronization.9.The method of any of claims 1-8, further comprising:switching (308) from the default beam to the UE-initiated beam or a TCI state indicated by the network entity (104) .10.A method of wireless communication at a network entity, (104) , comprising:transmitting (304) , to a user equipment (UE) (102) control signaling configuring at least one random access (RA) procedure from a plurality of RA procedures and configuring a list of transmission configuration indicator (TCI) states; andprior to an activation of at least one TCI state from the list of TCI states or a UE-initiated beam, communicating (306) with the UE (102) using at least one of: a default beam or a default pathloss-reference signal (PL-RS) based on at least one of:a quasi-co-location (QCL) parameter for a first downlink reference signal, oran uplink spatial transmission filter associated with the at least one RA procedure and a pathloss associated with a second downlink reference signal.11.The method of claim 10, wherein the at least one RA procedure is a 2-step RA procedure, and wherein the communicating (306) using the default beam is based on at least one of:a message A (MsgA) physical uplink shared channel (PUSCH) ,a MsgA physical random access channel (PRACH) ,the at least one TCI state from the list of TCI states,a synchronization signal block (SSB) or channel state information reference signal (CSI-RS) associated with the at least one RA procedure, ora configuration for the default beam.12.The method of claim 10, wherein the default beam is for a secondary cell (SCell) , and wherein the communicating (306) using the default beam is based on at least one of:a first synchronization signal block (SSB) for a time and frequency synchronization,a second SSB for the at least one TCI state from the list of TCI states, ora configuration for the default beam.13.The method of claim 10, wherein the at least one RA procedure is associated with a plurality of synchronization signal block (SSB) or channel state information reference signal (CSI-RS) resources, and wherein the communicating (306) using the default beam is based on at least one of:an SSB or CSI-RS resource index,a time-domain location of the SSB or CSI-RS,the control signaling,a UE report for the SSB or CSI-RS, orthe at least one TCI state from the list of TCI states.14.The method of claim 10, wherein the control signaling omits a configuration for the default PL-RS and the at least one of: the default beam or the default PL-RS is disabled, a pathloss being based on a synchronization signal block (SSB) used for decoding a master information block (MIB) or acquiring a time and frequency synchronization.15.An apparatus for wireless communication comprising a memory, a transceiver, and a processor coupled to the memory and the transceiver, the apparatus being configured to implement a method as in any of claims 1-14.
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