EP4736333A1 - Dci based dual tci switching for multiple-rx capable ue - Google Patents

Abstract

An apparatus configured to communicate with a first transmission and reception point (TRP) and a second TRP and configured to process, based on signaling received from a base station, first downlink control information (DCI) indicating to switch a first Transmission Configuration Indicator (TCI) for the first TRP to a first value to receive data on a first Physical Downlink Shared Channel (PDSCH) corresponding to the first TRP, process, based on signaling received from the base station, second DCI indicating to switch a second TCI for the second TRP to a second value to receive data on a second PDSCH corresponding to the second TRP and determine the second TCI cannot be switched to the second value prior to a start of the second PDSCH.

Description

PCI Based Dual TCI switching for Multiple-Rx Capable UE Inventors: Jie Cui, Chunxuan Ye, Dawei Zhang, Hong He, Manasa Raghavan, Xiang Chen and Yang Tang

BACKGROUND

[0001] A user equipment (UE) may have multiple antenna panels that allows the UE to receive signals from multiple transmission and reception points (mTRPs) . The UE uses reception beams to receive the signals from the mTRPs. Periodically, the network may switch the reception beams that are used by the UE, e.g., based on group-based beam reporting (GBBR) sent from the UE to the network. The network conveys this information to the UE using a Transmission Configuration Indicator (TCI) . When operating in mTRP mode, the network may send the TCI for each TRP in separate Downlink Control Information (DCI) , e.g., multiple DCI (mDCI) .

[0002] However, these mDCI may arrive at the UE at different times. In some instances, one of the DCIs may not arrive in time for the UE to switch the TCI to receive the Physical Downlink Shared Channel (PDSCH) transmission. The UE needs to understand how to apply the TCI switching included in the mDCI when this occurs .

Summary

[0003] Some example embodiments are related to an apparatus configured to communicate with a first transmission and reception point (TRP) and a second TRP, the apparatus having processing circuitry configured to process, based on signaling received from a base station, first downlink control information (DCI) indicating to switch a first Transmission Configuration Indicator (TCI) for the first TRP to a first value to receive data on a first Physical Downlink Shared Channel (PDSCH) corresponding to the first TRP, process, based on signaling received from the base station, second DCI indicating to switch a second TCI for the second TRP to a second value to receive data on a second PDSCH corresponding to the second TRP and determine the second TCI cannot be switched to the second value prior to a start of the second PDSCH.

[0004] Other example embodiments are related to a method performed by an apparatus configured to communicate with a first transmission and reception point (TRP) and a second TRP, the method including processing, based on signaling received from a base station, first downlink control information (DCI) indicating to switch a first Transmission Configuration Indicator (TCI) for the first TRP to a first value to receive data on a first Physical Downlink Shared Channel (PDSCH) corresponding to the first TRP, processing, based on signaling received from the base station, second DCI indicating to switch a second TCI for the second TRP to a second value to receive data on a second PDSCH corresponding to the second TRP and determining the second TCI cannot be switched to the second value prior to a start of the second PDSCH.

Brief Description of the Drawings

[0005] Fig. 1 shows an example network arrangement according to various example embodiments.

[0006] Fig. 2 shows an example UE according to various example embodiments. [0007] Fig. 3 shows an example base station according to various example embodiments.

[0008] Fig. 4 shows a first timing diagram showing signals exchanged between the UE and a TRP #1 and a TRP #2 of a base station according to various example embodiments.

[0009] Fig. 5 shows a second timing diagram showing signals exchanged between the UE and a TRP #1 and a TRP #2 of a base station according to various example embodiments.

[0010] Fig. 6 shows a third timing diagram showing signals exchanged between the UE and a TRP #1 and a TRP #2 of a base station according to various example embodiments.

[0011] Fig. 7 shows a fourth timing diagram showing signals exchanged between the UE and a TRP #1 and a TRP #2 of a base station according to various example embodiments.

[0012] Fig. 8 shows a fifth timing diagram showing signals exchanged between the UE and a TRP #1 and a TRP #2 of a base station according to various example embodiments.

Detailed Description

[0013] The example embodiments may be further understood with reference to the following description and the related appended drawings, wherein like elements are provided with the same reference numerals. The example embodiments relate to Transmission Configuration Indicator (TCI) switching when a UE is operating in multiple transmission and reception point (mTRP) and the network sends TCI switching commands for each TRP in separate Downlink Control Information (DCI) , e.g., multiple DCI

(mDCI) .

[0014] The example embodiments are described with regard to a user equipment (UE) . However, reference to a UE is merely provided for illustrative purposes. The example embodiments may be utilized with any electronic component that may establish a connection to a network and is configured with the hardware, software, and/or firmware to exchange information and data with the network. Therefore, the UE as described herein is used to represent any electronic component.

[0015] The example embodiments are also described with reference to a 5G New Radio (NR) network and a next generation node B (gNB) . However, the example embodiments may also be implemented in other types of networks, including but not limited to LTE networks, future evolutions of the cellular protocol (e.g., 5G-advanced, 6G networks) , or any other type of network .

[0016] The gNB may be configured with multiple transmission and reception points (TRPs) . Throughout this description, a TRP generally refers to a set of components configured to transmit and/or receive a beam. In some embodiments, multiple TRPs may be deployed locally at the gNB. For example, the gNB may include multiple antenna arrays/panels that are each configured to generate a different beam. In other embodiments, multiple TRPs may be deployed at various different locations and connected to the gNB via a backhaul connection. For example, multiple small cells may be deployed at different locations and connected to the gNB. However, these examples are merely provided for illustrative purposes. TRPs may be configured to be adaptable to a wide variety of different conditions and deployment scenarios. Thus, any reference to a TRP being a particular network component or multiple TRPs being deployed in a particular arrangement is merely provided for illustrative purposes. The TRPs described herein may represent any type of network component configured to transmit and/or receive a beam.

[0017] The example embodiments are described with regard to multi-TRP (mTRP) operation. From the perspective of the UE, mTRP operation may include establishing and maintaining a connection with multiple TRPs at the same time. When operating in mTRP mode, the UE may report information to the network about the transmission (Tx) or reception (Rx) beams using group-based beam reporting (GBBR) . The GBBR may be based on target Transmission Configuration Indicator (TCI) reference signals (RSs) or Quasi Co-Located (QCLed) Type D RSs. The network may use the information to update the TCI of the UE, e.g. , switch Tx or Rx beams used by the UE .

[0018] The example embodiments provide logic for a UE to handle scenarios where TCI switches are instructed by the network for mTRPs but the UE does not have time to apply the TCI switches before the corresponding Physical Downlink Shared Channel (PDSCH) is scheduled to arrive. For example, the Downlink Control Information (DCI) including the TCI switch does not arrive in a sufficient time to switch the TCI for one or more TRPs. The example logic will be described in greater detail below . [0019] Fig. 1 shows an example network arrangement 100 according to various example embodiments. The example network arrangement 100 includes a UE 110. The UE 110 may be any type of electronic component that is configured to communicate via a network, e.g. , mobile phones, tablet computers, desktop computers, smartphones, phablets, embedded devices, wearables, Internet of Things (loT) devices (including connected vehicles) , etc. An actual network arrangement may include any number of UEs being used by any number of users. Thus, the example of one UE 110 is merely provided for illustrative purposes.

[0020] The UE 110 may be configured to communicate with one or more networks. In the example of the network arrangement 100, the network with which the UE 110 may wirelessly communicate is a 5G NR radio access network (RAN) 120. The UE 110 may also communicate with other types of networks (e.g. , 5G cloud RAN, a next generation RAN (NG-RAN) , a legacy cellular network, etc. ) and the UE 110 may also communicate with networks over a wired connection. With regard to the example embodiments, the UE 110 may establish a connection with the 5G NR RAN 120. Therefore, the UE 110 may have a 5G NR chipset to communicate with the NR RAN 120.

[0021] The 5G NR RAN 120 may be portions of a cellular network that may be deployed by a network carrier (e.g., Verizon, AT&T, T-Mobile, etc. ) . The RAN 120 may include cells or base stations that are configured to send and receive traffic from UEs that are equipped with the appropriate cellular chip set. In this example, the 5G NR RAN 120 includes the next generation NodeB (gNB) 120A. However, reference to a gNB is merely provided for illustrative purposes, any appropriate base station or cell may be deployed (e.g., Node Bs, evolved NodeBs (eNBs) , home eNBs (HeNBs) , macrocells, microcells, small cells, femtocells, etc. ) . In this network arrangement 100 a single gNB 120A is shown for illustrative purposes. As described above, the example embodiments are described with reference to the gNB 120A having two or more TRPs . In some example embodiments, instead of two or more TRPs, the UE 110 may receive simultaneously receive signals from two or more base stations, e.g., two or more gNBs .

[0022] Any association procedure may be performed for the UE 110 to connect to the 5G NR RAN 120. For example, as discussed above, the 5G NR RAN 120 may be associated with a particular network carrier where the UE 110 and/or the user thereof has a contract and credential information (e.g. , stored on a SIM card) . Upon detecting the presence of the 5G NR RAN 120, the UE 110 may transmit the corresponding credential information to associate with the 5G NR RAN 120. More specifically, the UE 110 may associate with a specific cell (e.g. , gNB 120A) .

[0023] The network arrangement 100 also includes a cellular core network 130, the Internet 140, an IP Multimedia Subsystem (IMS) 150, and a network services backbone 160. The cellular core network 130 manages the traffic that flows between the cellular network and the Internet 140. The IMS 150 may be generally described as an architecture for delivering multimedia services to the UE 110 using the IP protocol. The IMS 150 may communicate with the cellular core network 130 and the Internet 140 to provide the multimedia services to the UE 110. The network services backbone 160 is in communication either directly or indirectly with the Internet 140 and the cellular core network 130. The network services backbone 160 may be generally described as a set of components (e.g., servers, network storage arrangements, etc.) that implement a suite of services that may be used to extend the functionalities of the UE 110 in communication with the various networks.

[0024] Fig. 2 shows an example UE 110 according to various example embodiments. The UE 110 will be described with regard to the network arrangement 100 of Fig. 1. The UE 110 may represent any electronic device and may include a processor 205, a memory arrangement 210, a display device 215, an input/output (I/O) device 220, a transceiver 225, and other components 230. The other components 230 may include, for example, an audio input device, an audio output device, a battery that provides a limited power supply, a data acquisition device, ports to electrically connect the UE 110 to other electronic devices, sensors to detect conditions of the UE 110, etc.

[0025] The processor 205 may be configured to execute a plurality of engines for the UE 110. For example, the engines may include an mTRP TCI switching engine 235 for performing operations related to switching TCIs for multiple TRPs .

[0026] The above referenced engine being an application (e.g., a program) executed by the processor 205 is only example. The functionality associated with the engines may also be represented as a separate incorporated component of the UE 110 or may be a modular component coupled to the UE 110, e.g., an integrated circuit with or without firmware. For example, the integrated circuit may include input circuitry to receive signals and processing circuitry to process the signals and other information. The engines may also be embodied as one application or separate applications. In addition, in some UEs, the functionality described for the processor 205 is split among two or more processors such as a baseband processor and an applications processor. The example embodiments may be implemented in any of these or other configurations of a UE .

[0027] The memory arrangement 210 may be a hardware component configured to store data related to operations performed by the UE 110. The display device 215 may be a hardware component configured to show data to a user while the I/O device 220 may be a hardware component that enables the user to enter inputs. The display device 215 and the I/O device 220 may be separate components or integrated together such as a touchscreen. The transceiver 225 may be a hardware component configured to establish a connection with the 5G-NR RAN 120. Accordingly, the transceiver 225 may operate on a variety of different frequencies or channels (e.g. , set of consecutive frequencies) .

[0028] The transceiver 225 includes circuitry configured to transmit and/or receive signals (e.g., control signals, data signals) . Such signals may be encoded with information implementing any one of the methods described herein. The processor 205 may be operably coupled to the transceiver 225 and configured to receive from and/or transmit signals to the transceiver 225. The processor 205 may be configured to encode and/or decode signals (e.g., signaling from a base station of a network) for implementing any one of the methods described herein .

[0029] Fig. 3 shows an example base station 300 according to various example embodiments. The base station 300 may represent the gNB 120A or any other access node through which the UE 110 may establish a connection and manage network operations.

[0030] The base station 300 may include a processor 305, a memory arrangement 310, an input/output (I/O) device 315, a transceiver 320, and other components 325. The other components 325 may include, for example, an audio input device, an audio output device, a battery, a data acquisition device, ports to electrically connect the base station 300 to other electronic devices and/or power sources, etc.

[0031] The processor 305 may be configured to execute a plurality of engines for the base station 300. For example, the engines may include an mTRP TCI configuration engine 330 for performing operations related to configuring a UE to perform TCI switches for multiple TRPs.

[0032] The memory arrangement 310 may be a hardware component configured to store data related to operations performed by the base station 300. The I/O device 315 may be a hardware component or ports that enable a user to interact with the base station 300. The transceiver 320 may be a hardware component configured to exchange data with the UE 110 and any other UE in the network arrangement 100. The transceiver 320 may operate on a variety of different frequencies or channels (e.g., set of consecutive frequencies) . Therefore, the transceiver 320 may include one or more components (e.g., radios) to enable the data exchange with the various networks and UEs.

[0033] The transceiver 320 includes circuitry configured to transmit and/or receive signals (e.g., control signals, data signals) . Such signals may be encoded with information implementing any one of the methods described herein. The processor 305 may be operably coupled to the transceiver 320 and configured to receive from and/or transmit signals to the transceiver 320. The processor 305 may be configured to encode and/or decode signals (e.g., signaling from a UE) for implementing any one of the methods described herein.

[0034] Fig. 4 shows a first timing diagram 400 showing signals exchanged between the UE 110 and a TRP #1 410 and a TRP #2 420 of a base station (e.g. , gNB 120A) according to various example embodiments. Initially, the UE 110 may have a first Rx TCI #m for the TRP #1 410 and a second Rx TCI # n for the TRP #2 420. At a first time, the UE 110 sends a GBBR report 425 to the gNB 120A. As described above, the GBBR report may include measurements or other information related to TCI RSs or QCLed Type D RSs. In this example, the GBBR report may be for paired RSs for the two TRPs . When the UE 110 is operating in mTRP mode, the UE 110 may not be able to use every possible Rx beam available for TRP #1 410 with every possible Rx beam available for TRP #2 420. For example, some beams are not compatible with other beams because of interference or other reasons. Thus, when the GBBR report is sent by the UE 110, the GBBR report may report RSs for compatible beams, e.g., beam pairs.

[0035] In the example of Fig. 4, based on the GBBR report

425, the network (e.g., gNB 120A) may decide to switch the TCI of the UE 110 for both the TRP #1 410 and a TRP #2 420. In this example, the TCI switch may be as follows, TRP #1 410 is to switch from Rx TCI #m to Rx TCI #1 and a TRP #2 420 is to switch from Rx TCI #n to Rx TCI #2. The network will send the TCI switch using Downlink Control Information (DCI) . In this example, the DCI will be sent for each TRP, e.g., a first DCI #1 430 for the TRP #1 410 and a second DCI #2 440 for the TRP #2 420. This may be termed multi-DCI (mDCI) .

[0036] As shown in Fig. 4, the mDCI may arrive at the UE 110 at different times, e.g., the DCI #1 430 arrives at the UE 110 prior to the DCI #2 440. This is only an example and it is possible that the DCI #1 430 arrives at the UE 110 after the DCI #2 440. As shown in Fig. 4, there is a time interval between the arrival of the DCI and the Physical Downlink Shared Channel (PDSCH) for which the TCI is to be used to receive data, e.g., ti between DCI #1 430 and PDSCH #1 450 and tz between DCI #2 440 and PDSCH #2 460.

[0037] When the time interval is greater than or equal to a threshold time (e.g., a time duration for QCL) , the UE 110 has enough time to perform the TCI switch before the start of the corresponding PDSCH. However, if the time interval is less than the threshold time, the UE 110 does not have enough time to perform the TCI switch before the start of the corresponding PDSCH. In this example, it may be considered that ti is greater than the threshold but t2 is less than the threshold, e.g., the UE 110 has enough time to switch the TCI to TCI #1 for the TRP #1 410 before the PDSCH #1 450 but not enough time to switch the TCI to TCI #2 for the TRP #2 420 before the PDSCH #2 460. Thus, if the UE were to switch the TCI for one TRP but not the other TRP, there may be a TCI mismatch. For example, the Rx beam for TRP #1 410 may not be compatible with the Rx beam for the TRP #2 420. [0038] The example embodiments provide logic for addressing the scenario where the UE has enough time to switch a TCI for a first TRP but not enough time to switch a TCI for a second TCI. The following will provide various examples of the logic that may be implemented by the UE 110 to address the scenario described by way of example in Fig. 4. Thus, the below examples each consider that the scenario of Fig. 4 has occurred.

[0039] In a first example embodiment, the UE 110 will implement logic to fallback to TCIs for both the TRP #1 410 and the TRP #2 420. In a first option of the first example, the UE 110 may fallback to any Physical Downlink Control Channel (PDCCH) TCIs that can support simultaneous reception. As described above, the TCI switch is indicated for data reception in the PDSCH. However, the UE 110 may also be configured to receive control information in the PDCCH. In this option, the UE 110 may fallback to PDCCH TCIs that support simultaneous reception, e.g., if the TCIs support simultaneous reception of control information on the PDCCH, it is likely the UE 110 can use the same TCIs to receive data on the PDSCH. For example, the UE 110 may fallback to a TCI #x of PDCCH for the PDSCH #1 450 and to a TCI ty of PDCCH for the PDSCH #2 460, where the UE 110 is able to receive TCI tx and TCI ty simultaneously.

[0040] In this option, the UE 110 may report this fallback TCI pair information (e.g., TCI #x for the PDSCH #1 450 and TCI ty for the PDSCH #2 460) to the network. For example, the UE 110 may report this fallback TCI pair information using Uplink Control Information (UCI) , Radio Resource Control (RRC) signaling or Medium Access Control Control Element (MAC-CE) signaling . [0041] In a second option of the first example, the UE 110 may fallback to PDCCH TCIs with a fixed Core Resource Set

(CORESET) index. This fallback may be defined by standard (e.g. , the 3GPP standards) or pre-programmed into the UE 110 and the network. For example, for the PDSCH tl 450, the UE 110 may fallback to the TCI of the corresponding CORESET #i. This CORESET may be a scheduling PDCCH, a PDCCH in the same active bandwidth part (BWP) , or a predefined index) . Similarly, for the PDSCH #2 460, the UE 110 may fallback to the TCI of the corresponding CORESET tj . Again, this CORESET may be a scheduling PDCCH, a PDCCH in the same active BWP, or a predefined index.

[0042] In a third option of the first example, the UE 110 may fallback to PDCCH TCIs with a lowest CORESET index that can support simultaneous reception. For example, for the PDSCH #1 450, the UE 110 may fallback to the TCI tx of its corresponding CORESET ti (scheduling PDCCH, PDCCH in the same active BWP, or predefined index) and for the PDSCH #2 460, the UE 110 may fallback to the TCI #y of its corresponding CORESET #j (scheduling PDCCH, PDCCH in the same active BWP, or predefined index) , where the UE 110 is able to receive TCI #x and TCI ty simultaneously. In this option, in some examples, the UE 110 reports the TCI #x and TCI ty pair to the network. In other examples, the UE 110 does not report the TCI tx and TCI ty pair to the network.

[0043] In a second example, the UE 110 will apply the TCI switches included in the mDCI . In the second example, the UE 110 may apply to the TCI switches at different times based on various examples as will be described in greater detail below.

[0044] Fig. 5 shows a second timing diagram 500 showing signals exchanged between the UE 110 and a TRP #1 510 and a TRP #2 520 of a base station (e.g., gNB 120A) according to various example embodiments. The scenario described above with reference to Fig. 4 may be similar to the scenario shown in Fig. 5, e.g., the UE 110 has enough time to switch the TCI to TCI #1 for the

TRP #1 510 before the PDSCH #1 550 but not enough time to switch the TCI to TCI #2 for the TRP #2 520 before the PDSCH #2 560.

The example of Fig. 5 will be used to describe a first option of the second example.

[0045] In a first option of the second example, the UE 110 will apply the TCI switch for the PDSCH #1 550 when received in the DCI #1 530, e.g., the UE 110 will switch the TCI to TCI #1 for the TRP #1 510. The UE 110 will then receive the data on the PDSCH #1 550 using the TCI #1 when the PDSCH #1 550 begins.

[0046] In the first option of the second example, because the UE 110 receives the DCI #2 540 in not enough time to switch the TCI to TCI #2 for the TRP #2 520 before the start of the PDSCH #2 560, the UE 110 will mute a portion 565 of the PDSCH #2 560 before completing the TCI switch, e.g., the UE 110 will not attempt to receive data on the PDSCH #2 560 during the muted portion 565. The muted portion corresponds to the time difference between tz and the threshold, e.g., the total time the UE 110 uses to switch the TCI to TCI #2 for the TRP #2 520. Once the TCI is switched as shown at time 570 in Fig. 5, the UE 110 will then receive the data on the PDSCH #2 560 using the TCI #2. [0047] Fig. 6 shows a third timing diagram 600 showing signals exchanged between the UE 110 and a TRP #1 610 and a TRP #2 620 of a base station (e.g. , gNB 120A) according to various example embodiments. The scenario described above with reference to Fig. 4 may be similar to the scenario shown in Fig. 6, e.g. , the UE 110 has enough time to switch the TCI to TCI #1 for the

TRP #1 610 before the PDSCH #1 650 but not enough time to switch the TCI to TCI #2 for the TRP #2 620 before the PDSCH #2 660.

The example of Fig. 6 will be used to describe a second option of the second example.

[0048] In a second option of the second example, the UE 110 will apply the TCI switch for the PDSCH #1 650 when received in the DCI #1 630, e.g., the UE 110 will switch the TCI to TCI #1 for the TRP #1 610. The UE 110 will then receive the data on the PDSCH #1 650 using the TCI #1 when the PDSCH #1 650 begins. This is the same as the first option for the PDSCH #1 650.

[0049] In the second option of the second example, because the UE 110 receives the DCI #2 640 in not enough time to switch the TCI to TCI #2 for the TRP #2 620 before the start of the PDSCH #2 560, the UE 110 will use a default TCI for a default portion 665 of the PDSCH #2 560 before completing the TCI switch. In some examples, the default TCI may be the currently configured TCI, e.g., the TCI #n. In other examples, the default TCI may be a PDCCH TCI (e.g. , PDCCH is scheduling PDCCH, PDCCH in the same active BWP, or a predefined index) .

[0050] In further examples, the default TCI may be the default TCI for mTRP as defined in TS38.214. For example, in TS38.214 a default TCI is defined as, for both the cases when tci-Present InDCI is set to 'enabled' and tci-PresentlnDCI is not configured in RRC connected mode, if the offset between the reception of the DL DCI and the corresponding PDSCH is less than the threshold timeDurationForQCL, the UE may assume that the DM- RS ports of PDSCH of a serving cell are quasi co-located with the RS ( s ) with respect to the QCL parameter (s) used for PDCCH quasi co-location indication of the CORESET associated with a monitored search space with the lowest controlResourceSetld in the latest slot in which one or more CORESETs within the active BWP of the serving cell are monitored by the UE .

[0051] The default portion 665 corresponds to the time difference between t2 and the threshold, e.g. , the total time the UE 110 uses to switch the TCI to TCI #2 for the TRP #2 620. Once the TCI is switched as shown at time 670 in Fig. 6, the UE 110 will then receive the data on the PDSCH #2 660 using the TCI #2.

[0052] Fig. 7 shows a fourth timing diagram 700 showing signals exchanged between the UE 110 and a TRP #1 710 and a TRP #2 720 of a base station (e.g. , gNB 120A) according to various example embodiments. The scenario described above with reference to Fig. 4 may be similar to the scenario shown in Fig. 7, e.g. , the UE 110 has enough time to switch the TCI to TCI #1 for the

TRP #1 710 before the PDSCH #1 750 but not enough time to switch the TCI to TCI #2 for the TRP #2 720 before the PDSCH #2 760.

The example of Fig. 7 will be used to describe a third option of the second example.

[0053] In the third option of the second example, the UE 110 will hold the TCI switching for both the PDSCH #1 750 and the PDSCH #2 760 until the shortest interval (e.g. , the interval between DCI#2 740 and PDSCH#2 760) reaches the time threshold, e.g., the time duration for QCL . This is illustrated in Fig. 7 as the hold portion 755 of the PDSCH #1 750 and the hold portion 765 of the PDSCH #2 760.

[0054] During the hold portions 755 and 765, the UE 110 will attempt to receive the data on the PDSCH #1 750 and the PDSCH #2 760. In some examples, the UE 110 may use the previously configured TCIs, e.g., the TCI #m for the PDSCH #1 750 and the TCI #n for the PDSCH #2 760. In other examples, the UE 110 may use the fallback TCIs as was described above with reference to the first example, e.g. , any of the options of TCI selection of the first example.

[0055] Once the time threshold is met, e.g. , the UE 110 can switch the TCI for the TRP #2 720 to TCI #2 as illustrated at time 770 of Fig. 7, the UE 110 may then apply the TCI switch for the PDSCH #1 750 and the TCI switch for the PDSCH #2 760. The UE 110 will then receive the data on the PDSCH #1 750 using the TCI #1 and the data on the PDSCH #2 760 using the TCI #2.

[0056] Fig. 8 shows a fifth timing diagram 800 showing signals exchanged between the UE 110 and a TRP #1 810 and a TRP #2 820 of a base station (e.g. , gNB 120A) according to various example embodiments. The scenario described above with reference to Fig. 4 may be similar to the scenario shown in Fig. 8, e.g. , the UE 110 has enough time to switch the TCI to TCI #1 for the TRP #1 810 before the first occasion of the PDSCH #1 850 but not enough time to switch the TCI to TCI #2 for the TRP #2 820 before the first occasion of the PDSCH #2 860. Unlike the previous timing diagrams of Figs. 4-7, the timing diagram 800 of Fig. 8 also shows a second occasion of the PDSCH #1 870 and a second occasion of the PDSCH #2 880. The purpose of illustrating these additional occasions of the PDSCH will be described in greater detail below. The example of Fig. 8 will be used to describe a fourth option of the second example.

[0057] In the fourth option of the second example, the UE 110 will use a default TCI for both the first occasion of the PDSCH #1 750 and the first occasion of the PDSCH #2 760. That is, even though the UE 110 has enough time to switch the TCI for the TRP#1 810 to the TCI #1 for the first occasion of the PDSCH #1 750, the UE 110 will not make this TCI switch but will use the default TCI for the first occasion of the PDSCH #1 750. In some examples, the default TCI may be the currently configured TCI, e.g., the TCI #m for the TRP #1 810 and the TCI #n for the TRP #1 820. In other examples, the default TCI may be any of the examples of default TCIs described above for the other examples, such as a PDCCH TCI (e.g. , PDCCH is scheduling PDCCH, PDCCH in the same active BWP, or a predefined index) , default TCI defined by TS 38.214, etc.

[0058] Aft er the completion of the first occasion of the

PDSCH #1 850 and the first occasion of the PDSCH #2 860, the UE 110 will have enough time to switch the TCI for both the TRP #1 810 and the TRP #2 820 to the TCI configured by the corresponding DCI (e.g. , TCI #1 for the TRP #1 810 as indicated by DCI #1 830 and TCI #2 for the TRP #2 820 as indicated by DCI #2 840) . Thus, for the second occasion of the PDSCH #1 870 and the second occasion of the PDSCH #2 880, the UE 110 will receive the data on the corresponding PDSCH using the configured TCI (e.g., the data on the PDSCH #1 870 using the TCI #1 and the data on the PDSCH #2 880 using the TCI #2) .

[0059] In a third example, the UE 110 may check the previous GBBR (e.g., the GBBR 425) to determine if the UE 110 can support simultaneous reception of the new TCI of PDSCH #1 450 (e.g., TCI #1) and a default TCI of PDSCH #2 460. For example, once the gNB 120A receives the GBBR report 425 and selects the TCI pair, the gNB 120A may clear its buffer of the GBBR report 425. However, the UE 110 may retain the GBBR report in its buffer at least until the next GBBR report is generated. When the UE 110 experiences the scenario described with reference to Fig. 4, the UE 110 may refer back to the GBBR report that is still in the buffer to determine if the new TCI for the TCI of PDSCH #1 450 (e.g., TCI #1) and a default TCI of PDSCH #2 460 may be used, e.g., was that TCI pair (new TCI of PDSCH #1 450 and default TCI of PDSCH #2 460) reported in the GBBR report.

[0060] If yes, in some examples, the UE 110 may then indicate which previous GBBR pair is used or which TCI pair is used to network. In other examples, the UE 110 and the network assume that one specific TCI pair (e.g., specific index) in the previous GBBR report will be used. For example, the specific index may be the lowest index.

[0061] On the other hand, if the TCI pair is not included in the previous GBBR report, the UE 110 may use any of the options as described above with reference to the first and second examples . [0062] In the third example, the default TCI of PDSCH#2 may be the PDCCH TCI (e.g., PDCCH is scheduling PDCCH, PDCCH in the same active BWP, or a predefined index) . The default TCI may also be the default TCI for mTRP as defined in TS38.214.

Examples

[0063] In a first example, a method performed by an apparatus configured to communicate with a first transmission and reception point (TRP) and a second TRP, the method comprising processing, based on signaling received from a base station, first downlink control information (DCI) indicating to switch a first Transmission Configuration Indicator (TCI) for the first TRP to a first value to receive data on a first Physical Downlink Shared Channel (PDSCH) corresponding to the first TRP, processing, based on signaling received from the base station, second DCI indicating to switch a second TCI for the second TRP to a second value to receive data on a second PDSCH corresponding to the second TRP and determining the second TCI cannot be switched to the second value prior to a start of the second PDSCH.

[0064] In a second example, the method of the first example, further comprising switching the first TCI to a third value, wherein the third value corresponds to a TCI associated with a first Physical Downlink Control Channel (PDCCH) of the first TRP and switching the second TCI to a fourth value, wherein the fourth value corresponds to a TCI associated with a second Physical Downlink Control Channel (PDCCH) of the second TRP.

[0065] In a third example, the method of the second example, wherein signals are received simultaneously using the first TCI that is set to the third value and the second TCI that is set to the fourth value .

[ 0066] In a fourth example , the method of the third example , further comprising generating, for transmission to the base station, an indication that the first TCI is set to the third value and the second TCI is set to the fourth value .

[ 0067 ] In a fi fth example , the method of the third example, wherein the third value is based on a lowest core resource set ( CORESET ) index for the first TRP and the fourth value is based on a lowest CORESET index for the second TRP .

[ 0068 ] In a sixth example , the method of the fifth example, wherein the lowest CORESET index for each of the first TRP and the second TRP is based on a scheduling PDCCH, a PDCCH in the same active bandwidth part (BWP ) as the corresponding PDSCH, or a predefined index associated with the corresponding first or second TRP .

[ 0069] In a seventh example , the method of the second example , wherein the third value is based on a fixed core resource set ( CORESET ) index for the first TRP and the fourth value is based on a fixed CORESET index for the second TRP .

[ 0070 ] In an eighth example , the method of the seventh example , wherein the fixed CORESET index for each of the first TRP and the second TRP is based on a scheduling PDCCH, a PDCCH in the same active bandwidth part (BWP) as the corresponding PDSCH, or a predefined index associated with the corresponding first or second TRP . [0071] In a ninth example, the method of the first example, further comprising switching the first TCI to the first value, processing, based on signals received from the first TRP using the first TCI that is set to the first value, data on the first PDSCH, muting a starting portion of the second PDSCH, wherein the starting portion corresponds to a first time from the start of the second PDSCH to a second time during the second PDSCH used to switch the second TCI to the second value, switching the second TCI to the second value, processing, based on signals received from the second TRP using the second TCI that is set to the second value, data on the second PDSCH from the second time.

[0072] In a tenth example, the method of the first example, further comprising switching the first TCI to the first value, processing, based on signals received from the first TRP using the first TCI that is set to the first value, data on the first PDSCH, setting the second TCI to a default value at the start of the second PDSCH, processing, based on signals received from the second TRP using the second TCI that is set to the default value, data on the second PDSCH, switching the second TCI to the second value at a time after the start of the second PDSCH and before an end of the second PDSCH and processing, based on signals received from the second TRP using the second TCI that is set to the second value, data on the second PDSCH from the time .

[0073] In an eleventh example, the method of the tenth example, wherein the default value corresponds to a current TCI value, a TCI value of a scheduling PDCCH, a TCI value of a PDCCH in the same active bandwidth part (BWP) as the second PDSCH, or a predefined index associated with the second TRP.

[0074] In a twelfth example, the method of the tenth example, wherein the default value corresponds to a TCI that is quasi colocated (QCL) with reference signals with respect to QCL parameters used for a PDCCH quasi co-location indication of a core resources set (CORESET) associated with a monitored search space with a lowest CORESET identification in a latest slot in which one or more CORESETs within an active bandwidth part (BWP) of a serving cell is monitored by the UE .

[0075] In a thirteenth example, the method of the first example, further comprising setting the first TCI to a first default value at the start of the first PDSCH, processing, based on signals received from the first TRP using the first TCI that is set to the first default value, data on the first PDSCH, setting the second TCI to a second default value at the start of the second PDSCH, processing, based on signals received from the second TRP using the second TCI that is set to the second default value, data on the second PDSCH, switching the first TCI to the first value at a time after the start of the first PDSCH and before an end of the first PDSCH, wherein the time is based on an amount of time used to switch the second TCI to the second value, processing, based on signals received from the first TRP using the first TCI that is set to the first value, data on the first PDSCH from the time, switching the second TCI to the second value at the time after the start of the second PDSCH and before an end of the second PDSCH and processing, based on signals received from the second TRP using the second TCI that is set to the second value, data on the second PDSCH from the time .

[0076] In a fourteenth example, the method of the thirteenth example, wherein the first default value corresponds to a current TCI value of the first TCI and the second default value corresponds to a current TCI value of the second TCI.

[0077] In a fifteenth example, the method of the thirteenth example, wherein the first default value corresponds to a TCI associated with a first Physical Downlink Control Channel (PDCCH) of the first TRP and the second default value corresponds to a TCI associated with a second Physical Downlink Control Channel (PDCCH) of the second TRP.

[0078] In a sixteenth example, the method of the first example, further comprising setting the first TCI to a first default value for the first PDSCH, processing, based on signals received from the first TRP using the first TCI that is set to the first default value, data on the first PDSCH, setting the second TCI to a second default value for the second PDSCH and processing, based on signals received from the second TRP using the second TCI that is set to the second default value, data on the second PDSCH.

[0079] In a seventeenth example, the method of the sixteenth example, wherein the first default value corresponds to a current TCI value of the first TCI and the second default value corresponds to a current TCI value of the second TCI. [ 0080 ] In an eighteenth example , the method of the sixteenth example , wherein the first default value corresponds to a TCI associated with a first Physical Downlink Control Channel ( PDCCH) of the first TRP and the second default value corresponds to a TCI associated with a second Physical Downlink Control Channel ( PDCCH) of the second TRP .

[ 0081 ] In a nineteenth example, the method of the first example , further comprising generating, for transmission to the base station, a group-based beam reporting (GBBR) report for the first TRP and the second TRP and determining whether simultaneous reception is supported using the first TCI that is set to the first value and the second TCI that is set to a default value , wherein the processing circuitry determines simultaneous reception is supported based on the GBBR report .

[ 0082 ] In a twentieth example, the method of the nineteenth example , wherein the default value corresponds to a TCI value of a scheduling PDCCH, a TCI value of a PDCCH in the same active bandwidth part (BWP ) as the second PDSCH, or a predefined index associated with the second TRP .

[ 0083] In a twenty first example , the method of the nineteenth example , wherein the default value corresponds to a TCI that is quasi co-located ( QCL) with reference signals with respect to QCL parameters used for a PDCCH quasi co-location indication of a core resources set ( CORESET ) associated with a monitored search space with a lowest CORESET identi fication in a latest slot in which one or more CORESETs within an active bandwidth part (BWP ) of a serving cell . [0084] In a twenty second example, the method of the nineteenth example, wherein, when simultaneous reception is supported, the method further comprising processing, based on signals received from the first TRP using the second TCI that is set to the first value, data on the first PDSCH and processing, based on signals received from the second TRP using the second TCI that is set to the default value, data on the second PDSCH.

[0085] In a twenty third example, the method of the twenty second example, further comprising generating, for transmission to the base station, an indication that the first TCI is set to the first value and the second TCI is set to the default value.

[0086] In a twenty fourth example, the method of the twenty second example, wherein the first value and the default value are based on a predefined index.

[0087] In a twenty fifth example, the method of the twenty fourth example, wherein the predefined index is a lowest index.

[0088] In a twenty sixth example, a processor configured to perform any of the methods of the first through twenty fifth examples .

[0089] In a twenty seventh example, a user equipment (UE) configured to perform any of the methods of the first through twenty fifth examples.

[0090] Those skilled in the art will understand that the above-described example embodiments may be implemented in any suitable software or hardware configuration or combination thereof . An example hardware platform for implementing the example embodiments may include , for example, an Intel x86 based platform with compatible operating system, a Windows OS , a Mac platform and MAC OS , a mobile device having an operating system such as iOS , Android, etc . The example embodiments of the above described method may be embodied as a program containing lines of code stored on a non-transitory computer readable storage medium that , when compiled, may be executed on a processor or microprocessor .

[ 0091 ] Although this application described various embodiments each having different features in various combinations , those skilled in the art will understand that any of the features of one embodiment may be combined with the features of the other embodiments in any manner not speci fically disclaimed or which is not functionally or logically inconsistent with the operation of the device or the stated functions of the disclosed embodiments .

[ 0092 ] It is well understood that the use of personally identi fiable information should follow privacy policies and practices that are generally recogni zed as meeting or exceeding industry or governmental requirements for maintaining the privacy of users . In particular, personally identifiable information data should be managed and handled so as to minimi ze risks of unintentional or unauthori zed access or use , and the nature of authori zed use should be clearly indicated to users .

[ 0093] It will be apparent to those skilled in the art that various modi fications may be made in the present disclosure , without departing from the spirit or the scope of the disclosure . Thus , it is intended that the present disclosure cover modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalent .

Claims

What is claimed :

1 . An apparatus configured to communicate with a first transmission and reception point ( TRP ) and a second TRP, the apparatus comprising processing circuitry configured to : process , based on signaling received from a base station, first downlink control information ( DCI ) indicating to switch a first Transmission Configuration Indicator ( TCI ) for the first TRP to a first value to receive data on a first Physical Downlink Shared Channel ( PDSCH) corresponding to the first TRP ; process , based on signaling received from the base station, second DCI indicating to switch a second TCI for the second TRP to a second value to receive data on a second PDSCH corresponding to the second TRP ; and determine the second TCI cannot be switched to the second value prior to a start of the second PDSCH .

2 . The apparatus of claim 1 , wherein the processing circuitry is further configured to : switch the first TCI to a third value , wherein the third value corresponds to a TCI associated with a first Physical Downlink Control Channel ( PDCCH) of the first TRP; and switch the second TCI to a fourth value, wherein the fourth value corresponds to a TCI associated with a second Physical Downlink Control Channel ( PDCCH) of the second TRP .

3 . The apparatus of claim 2 , wherein signals are received simultaneously using the first TCI that is set to the third value and the second TCI that is set to the fourth value .

4 . The apparatus of claim 3 , wherein the processing circuitry is further configured to : generate , for transmission to the base station, an indication that the first TCI is set to the third value and the second TCI is set to the fourth value .

5 . The apparatus of claim 3 , wherein the third value is based on a lowest core resource set ( CORESET ) index for the first TRP and the fourth value is based on a lowest CORESET index for the second TRP .

6 . The apparatus of claim 2 , wherein the third value is based on a fixed core resource set ( CORESET ) index for the first TRP and the fourth value is based on a fixed CORESET index for the second TRP .

7 . The apparatus of claim 1 , wherein the processing circuitry is further configured to : switch the first TCI to the first value; process , based on signals received from the first TRP using the first TCI that is set to the first value, data on the first PDSCH; mute a starting portion of the second PDSCH, wherein the starting portion corresponds to a first time from the start of the second PDSCH to a second time during the second PDSCH used to switch the second TCI to the second value ; switch the second TCI to the second value ; and process , based on signals received from the second TRP using the second TCI that is set to the second value , data on the second PDSCH from the second time .

8 . The apparatus of claim 1 , wherein the processing circuitry is further configured to : switch the first TCI to the first value; process, based on signals received from the first TRP using the first TCI that is set to the first value, data on the first PDSCH; set the second TCI to a default value at the start of the second PDSCH; process, based on signals received from the second TRP using the second TCI that is set to the default value, data on the second PDSCH; switch the second TCI to the second value at a time after the start of the second PDSCH and before an end of the second PDSCH; and process, based on signals received from the second TRP using the second TCI that is set to the second value, data on the second PDSCH from the time.

9. The apparatus of claim 8, wherein the default value corresponds to a current TCI value, a TCI value of a scheduling PDCCH, a TCI value of a PDCCH in a same active bandwidth part (BWP) as the second PDSCH, or a predefined index associated with the second TRP .

10. The apparatus of claim 8, wherein the default value corresponds to a TCI that is quasi co-located (QCL) with reference signals with respect to QCL parameters used for a PDCCH quasi co-location indication of a core resources set (CORESET) associated with a monitored search space with a lowest CORESET identification in a latest slot in which one or more CORESETs within an active bandwidth part (BWP) of a serving cell is monitored.

11 . The apparatus of claim 1 , wherein the processing circuitry is further configured to : set the first TCI to a first default value at the start of the first PDSCH; process , based on signals received from the first TRP using the first TCI that is set to the first default value , data on the first PDSCH; set the second TCI to a second default value at the start of the second PDSCH; process , based on signals received from the second TRP using the second TCI that is set to the second default value , data on the second PDSCH; switch the first TCI to the first value at a time after the start of the first PDSCH and before an end of the first PDSCH, wherein the time is based on an amount of time used to switch the second TCI to the second value ; process , based on signals received from the first TRP using the first TCI that is set to the first value, data on the first PDSCH from the time ; switch the second TCI to the second value at the time after the start of the second PDSCH and before an end of the second PDSCH; and process , based on signals received from the second TRP using the second TCI that is set to the second value , data on the second PDSCH from the time .

12 . The apparatus of claim 11 , wherein the first default value corresponds to a current TCI value of the first TCI and the second default value corresponds to a current TCI value of the second TCI .

13. The apparatus of claim 11, wherein the first default value corresponds to a TCI associated with a first Physical Downlink Control Channel (PDCCH) of the first TRP and the second default value corresponds to a TCI associated with a second Physical Downlink Control Channel (PDCCH) of the second TRP.

14. The apparatus of claim 1, wherein the processing circuitry is further configured to: set the first TCI to a first default value for the first PDSCH; process, based on signals received from the first TRP using the first TCI that is set to the first default value, data on the first PDSCH; set the second TCI to a second default value for the second PDSCH; and process, based on signals received from the second TRP using the second TCI that is set to the second default value, data on the second PDSCH.

15. The apparatus of claim 14, wherein the first default value corresponds to a current TCI value of the first TCI and the second default value corresponds to a current TCI value of the second TCI.

16. The apparatus of claim 14, wherein the first default value corresponds to a TCI associated with a first Physical Downlink Control Channel (PDCCH) of the first TRP and the second default value corresponds to a TCI associated with a second Physical Downlink Control Channel (PDCCH) of the second TRP.

17 . The apparatus of claim 1 , wherein the processing circuitry is further configured to : generate , for transmission to the base station, a group- based beam reporting ( GBBR) report for the first TRP and the second TRP; and determine whether simultaneous reception is supported using the first TCI that is set to the first value and the second TCI that is set to a default value , wherein the processing circuitry determines simultaneous reception is supported based on the GBBR report .

18 . The apparatus of claim 17 , wherein the default value corresponds to a TCI value of a scheduling PDCCH, a TCI value of a PDCCH in a same active bandwidth part (BWP) as the second PDSCH, or a predefined index associated with the second TRP .

19 . The apparatus of claim 17 , wherein the default value corresponds to a TCI that is quasi co-located ( QCL) with reference signals with respect to QCL parameters used for a PDCCH quasi co-location indication of a core resources set ( CORESET ) associated with a monitored search space with a lowest CORESET identi fication in a latest slot in which one or more CORESETs within an active bandwidth part (BWP ) of a serving cell .

20 . The apparatus of claim 17 , wherein, when simultaneous reception is supported, the processing circuitry is further configured to : process , based on signals received from the first TRP using the second TCI that is set to the first value , data on the first PDSCH; and process, based on signals received from the second TRP using the second TCI that is set to the default value, data on the second PDSCH.