WO2024007316A1

WO2024007316A1 - Methods and apparatuses for multi-trp operation

Info

Publication number: WO2024007316A1
Application number: PCT/CN2022/104678
Authority: WO
Inventors: Kai Liu
Original assignee: Shenzhen Tcl New Technology Co., Ltd.
Priority date: 2022-07-08
Filing date: 2022-07-08
Publication date: 2024-01-11

Abstract

Methods and apparatuses for multiple-transmission reception point (multi-TRP) operation are disclosed. The method performed by a user equipment (UE) includes being configured with a first signaling from a network, wherein the first signaling is used for multi-TRP operation and/or receiving a second signaling from the network, wherein the second signaling is used for multi-TRP operation.

Description

METHODS AND APPARATUSES FOR MULTI-TRP OPERATION

BACKGROUND OF DISCLOSURE

1. Field of the Disclosure

The present disclosure relates to the field of wireless communication systems, and more particularly, to methods and apparatuses for multiple-transmission reception point (multi-TRP) operation, for example, the wireless communication systems operating in multiple-input multiple-output (MIMO) systems. More specifically, the target is to provide some solutions to activating and indicating transmission configuration indication (TCI) states for multi-TRP operation with unified TCI framework.

2. Description of the Related Art

MIMO is an effective approach to enhance the capacity of a radio link due to the multiplexing of both transmit and receive antennas. MIMO refers to a practical technique for sending and receiving more than one data signal simultaneously over the same radio channel, which improves the performance of spectral efficiency greatly. Progress has been achieved to enable the use of multi-TRP operation which is one of the key technologies of MIMO in an efficient manner.

In current art, single TRP operation is with unified TCI framework, and multi-TRP operation is without unified TCI framework. How to provide solutions to activating and indicating transmission configuration indication (TCI) states for multi-TRP operation with unified TCI framework is an open issue.

SUMMARY

An object of the present disclosure is to propose methods and apparatuses for multiple-transmission reception point (multi-TRP) operation.

In a first aspect of the present disclosure, a method for multi-TRP operation performed by a user equipment (UE) includes being configured with a first signaling from a network, wherein the first signaling is used for multi-TRP operation, and/or receiving a second signaling from the network, wherein the second signaling is used for multi-TRP operation.

In a second aspect of the present disclosure, a method for multi-TRP operation performed by a network includes configuring a first signaling to a user equipment (UE) , wherein the first signaling is used for multi-TRP operation, and/or transmitting a second signaling to the UE, wherein the second signaling is used for multi-TRP operation.

In a third aspect of the present disclosure, a user equipment (UE) comprises a memory, a transceiver, and a processor coupled to the memory and the transceiver. The processor is configured to perform the above method.

In a fourth aspect of the present disclosure, a network comprises a memory, a transceiver, and a processor coupled to the memory and the transceiver. The processor is configured to perform the above method.

In a fifth aspect of the present disclosure, a non-transitory machine-readable storage medium has stored thereon instructions that, when executed by a computer, cause the computer to perform the above method.

In a sixth aspect of the present disclosure, a chip includes a processor, configured to call and run a computer program stored in a memory, to cause a device in which the chip is installed to execute the above method.

In a seventh aspect of the present disclosure, a computer readable storage medium, in which a computer program is stored, causes a computer to execute the above method.

In an eight aspect of the present disclosure, a computer program product includes a computer program, and the computer program causes a computer to execute the above method.

In a ninth aspect of the present disclosure, a computer program causes a computer to execute the above method.

BRIEF DESCRIPTION OF DRAWINGS

In order to illustrate the embodiments of the present disclosure or related art more clearly, the following figures will be described in the embodiments are briefly introduced. It is obvious that the drawings are merely some embodiments of the present disclosure, a person having ordinary skill in this field can obtain other figures according to these figures without paying the premise.

FIG. 1 is a schematic diagram illustrating an example of a multi-TRP operation according to an embodiment of the present disclosure.

FIG. 2 is a block diagram of one or more user equipments (UEs) and a base station (e.g., gNB) of communication in a communication network system according to an embodiment of the present disclosure.

FIG. 3 is a flowchart illustrating a method for multi-TRP operation performed by a UE according to an embodiment of the present disclosure.

FIG. 4 is a flowchart illustrating method for multi-TRP operation by a base station according to an embodiment of the present disclosure.

FIG. 5 is a schematic diagram illustrating two examples of MAC CEs according to an embodiment of the present disclosure.

FIG. 6 is a schematic diagram illustrating an example of a DCI indicating TCI states once from an activated TCI state list corresponding to a TRP and the other DCI indicating TCI states from the other activated TCI state list corresponding to the other TRPs according to an embodiment of the present disclosure.

FIG. 7 is a schematic diagram illustrating an example of one DCI indicating TCI states from one activated TCI state list corresponding to one TRPs and TCI states from the other activated TCI state list corresponding to the other TRPs simultaneously according to an embodiment of the present disclosure.

FIG. 8 is a schematic diagram illustrating an example that a TCI filed in a DCI is extended to 4 bits, and the additive 1 bit is used to indicate TRP according to an embodiment of the present disclosure.

FIG. 9 is a schematic diagram illustrating an example that a TCI filed in a DCI is extended to 6 bits according to an embodiment of the present disclosure.

FIG. 10 is a schematic diagram illustrating an example that PUCCH resource or PUCCH resource sets can be associated with different TRPs according to an embodiment of the present disclosure.

FIG. 11 is a block diagram of a system for wireless communication according to an embodiment of the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the present disclosure are described in detail with the technical matters, structural features, achieved objects, and effects with reference to the accompanying drawings as follows. Specifically, the terminologies in the embodiments of the present disclosure are merely for describing the purpose of the certain embodiment, but not to limit the disclosure.

Multiple-input multiple-output (MIMO) is one of the key technologies in new radio (NR) systems and is successful in commercial deployment. In the communication system of MIMO, both UE and base station comprise of a large number of antenna elements. Especially for base station, these antenna elements can be distributed in different panels, as illustrated in FIG. 1. FIG. 1. illustrates that, in multiple-transmission reception point (multi-TRP) operation, each panel is placed at different position such that the base station can communicate with the UE better. Specifically, panels at different positions are named as multi-TRP in current specification. Both downlink (DL) and uplink (UL) channels can benefit from multi-TRP operation by leveraging spatial diversity to improve the throughput and reliability of transmission in case of unpredictable blockage between a TRP and a UE especially in a frequency range 2 (FR 2) .

FIG. 2 illustrates that, in some embodiments, one or more user equipments (UEs) 10 and a base station (e.g., gNB) 20 (or can be called a network) for communication in a communication network system 40 according to an embodiment of the present disclosure are provided. The communication network system 40 includes the one or more UEs 10 and the base station 20. The one or more UEs 10 may include a memory 12, a transceiver 13, and a processor 11 coupled to the memory 12 and the transceiver 13. The base station 20 may include a memory 22, a transceiver 23, and a processor 21 coupled to the memory 22 and the transceiver 23. The

processor

11 or 21 may be configured to implement proposed functions, procedures and/or methods described in this description. Layers of radio interface protocol may be implemented in the

processor

11 or 21. The

memory

12 or 22 is operatively coupled with the

processor

11 or 21 and stores a variety of information to operate the

processor

11 or 21. The

transceiver

13 or 23 is operatively coupled with the

processor

11 or 21, and the

transceiver

13 or 23 transmits and/or receives a radio signal.

The

processor

11 or 21 may include application-specific integrated circuit (ASIC) , other chipset, logic circuit and/or data processing device. The

memory

12 or 22 may include read-only memory (ROM) , random access memory (RAM) , flash memory, memory card, storage medium and/or other storage device. The

transceiver

13 or 23 may include baseband circuitry to process radio frequency signals. When the embodiments are implemented in software, the techniques described herein can be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. The modules can be stored in the

memory

12 or 22 and executed by the

processor

11 or 21. The

memory

12 or 22 can be implemented within the

processor

11 or 21 or external to the

processor

11 or 21 in which case those can be communicatively coupled to the

processor

11 or 21 via various means as is known in the art.

In some embodiments, the processor 11 is configured with a first signaling from the network 20, wherein the first signaling is used for multi-TRP operation, and/or the transceiver 13 is configured to receive a second signaling from the network 20, wherein the second signaling is used for multi-TRP operation.

In some embodiments, the processor 21 is configured to configure a first signaling to the UE 10, wherein the first signaling is used for multi-TRP operation, and/or the transceiver 23 is configured to transmit a second signaling to the UE 10, wherein the second signaling is used for multi-TRP operation.

FIG. 3 is a flowchart illustrating a method 300 for multi-TRP operation performed by a UE according to an embodiment of the present disclosure. In some embodiments, the method 300 for multi-TRP operation performed by the UE includes: a step 310, being configured with a first signaling from a network, wherein the first signaling is used for multi-TRP operation, and/or a step 320, receiving a second signaling from the network, wherein the second signaling is used for multi-TRP operation.

FIG. 4 is a flowchart illustrating a method 400 for multi-TRP operation by a base station (or can be called a network) according to an embodiment of the present disclosure. In some embodiments, the method 400 for multi-TRP operation performed by the network includes: a step 410, configuring a first signaling to a UE, wherein the first signaling is used for multi-TRP operation, and/or a step 420, transmitting a second signaling to the UE, wherein the second signaling is used for multi-TRP operation.

In some embodiments, the first signaling configures different join/downlink (DL) or uplink (UL) transmission configuration indication (TCI) state lists corresponding to different TRPs and/or different joint/separate TCI state indications corresponding to the different TRPs, and/or the second signaling activates and/or indicates TCI states corresponding to the different TRPs and/or supports a switching between a joint TCI state and a separate TCI state. In some embodiments, the first signaling comprises a radio resource control (RRC) signaling, and the second signaling comprises a medium access control (MAC) control element (CE) , a downlink control information (DCI) , and/or a higher parameter.

In some embodiments, the MAC CE comprises a legacy unified TCI state activation/deactivation MAC CE, the legacy unified TCI state activation/deactivation MAC CE is associated with different time units, and the legacy unified TCI state activation/deactivation MAC CE activates the TCI states corresponding to the different TRPs. In some embodiments, at an odd time unit, the TCI states indicated by TCI state identifier (ID) fields in the legacy unified TCI state activation/deactivation MAC CE are from a first joint/DL or UL TCI state list corresponding to a first TRP, and/or at an even time unit, the TCI states indicated by the TCI state ID fields are from a second joint/DL or UL TCI state list corresponding to a second TRP.

In some embodiments, the MAC CE comprises a first legacy unified TCI state activation/deactivation MAC CE and a second legacy unified TCI state activation/deactivation MAC CE transmitted simultaneously at a time unit. In some embodiments, the TCI states indicated by TCI state ID fields in the first legacy unified TCI state activation/deactivation MAC CE are from a first joint/DL or UL TCI state list corresponding to a first TRP, and/or the TCI states indicated by the TCI state ID fields in the second legacy unified TCI state activation/deactivation MAC CE are from a second joint/DL or UL TCI state list corresponding to a second TRP.

In some embodiments, a first field of R fields in at least one of the legacy unified TCI state activation/deactivation MAC CE, the first the legacy unified TCI state activation/deactivation MAC CE, and the second the legacy unified TCI state activation/deactivation MAC CE is used to indicate an association between one TCI state indicated by one TCI state ID filed and one TRP. In some embodiments, if a first field of R fields indicates a first value, the TCI states indicated by the TCI state ID fields are from the first joint/DL or UL TCI state list corresponding to the first TRP, and/or if the first field of R fields indicates a second value, the TCI states indicated by the TCI state ID fields are from the second joint/DL or UL TCI state list corresponding to the second TRP.

In some embodiments, one TCI state ID filed in at least one of the legacy unified TCI state activation/deactivation MAC CE, the first the legacy unified TCI state activation/deactivation MAC CE, and the second the legacy unified TCI state activation/deactivation MAC CE is used to activate up to two TCI states corresponding to the different TRPs. In some embodiments, a second field of R fields in at least one of the legacy unified TCI state activation/deactivation MAC CE, the first the legacy unified TCI state activation/deactivation MAC CE, and the second the legacy unified TCI state activation/deactivation MAC CE is used to indicate whether one TCI state ID filed actives one or two TCI states. In some embodiments, if a number of the TCI state indicated by the one TCI state ID filed is one, the association between the TCI state and the TRP is indicated by the first field of R fields. In some embodiments, the first field of R fields is further used to indicate a TRP index.

In some embodiments, in at least one of the legacy unified TCI state activation/deactivation MAC CE, the first the legacy unified TCI state activation/deactivation MAC CE, and the second the legacy unified TCI state activation/deactivation MAC CE, all of TCI state ID fields share the first field of R fields and the second field of R fields, or each TCI state ID filed has the first field of R fields and the second field of R fields.

In some embodiments, the DCI comprises a first DCI and a second DCI, the first DCI indicates the TCI states from an activated TCI state list corresponding to one TRP and the second DCI indicates the TCI states from another activated TCI state list corresponding to another TRP. In some embodiments, the first DCI and the second DCI are located at different time units.

In some embodiments, the DCI indicates the TCI states from an activated TCI state list corresponding to one TRP, and the DCI indicates the TCI states from another activated TCI state list corresponding to another TRP simultaneously. In some embodiments, one TCI filed in the DCI is extended to 4 bits, an additive 1 bit of the 4 bits is used to indicate the TRP. In some embodiments, one TCI filed in the DCI is extended to 6 bits, front 3 bits of the 6 bits are used to indicate the TCI states from the one activated TCI state list corresponding to the one TRP, and latter 3 bits of the 6 bits are used to indicate the TCI states from the another activated TCI state list corresponding to the another TRP.

In some embodiments, the DCI comprises a DL DCI, a TRP indicator for a physical uplink control channel (PUCCH) filed with 1 bit added in the DL DCI is used to indicate an association between a PUCCH resource and one TRP. In some embodiments, when the UE receives the TRP indicator for the PUCCH field in the DL DCI, the UE transmits a PUCCH indicated by the PUCCH field by using one TCI state corresponding to the TRP. In some embodiments, the higher parameter comprises PUCCH-Reousrce or PUCCH-ResourceSet, a TRP indicator RRC signaling with 1 bit added in the higher parameter is used to indicate an association between a PUCCH resource or a PUCCH resource set and one TRP. In some embodiments, when the UE receives a PUCCH resource indicator in the DCI, the UE transmits an indicated PUCCH by using the TCI state corresponding to the TRP according to the TRP indicator RRC signaling in the higher parameter. In some embodiments, PUCCH resources or PUCCH resource sets are associated with the different TRPs, and/or the PUCCH resources or the PUCCH resource sets are divided into different parts, and the different parts are corresponding to the different TRPs. In some embodiments, the TRP indicator is an explicit TRP index or another index associated with TRP such as an index of a CORESET pool, an SRS resource set index, or a CSI-RS resource set index.

In some embodiments, the higher parameter is extended to TRP-specific. In some embodiments, the higher parameter comprises unifiedtci-StateType-TRP1 and unifiedtci-StateType-TRP2, the unifiedtci-StateType-TRP1 indicates that the first TRP is the joint TCI state or the separate TCI state, and the unifiedtci-StateType-TRP2 indicates that the second TRP is the joint TCI state or the separate TCI state. In some embodiments, for multi-TRP operation, the MAC CE is used to support a dynamic switching between the joint TCI state and the separate TCI state. In some embodiments, the MAC CE has 2 bits, where a former bit of the 2 bits indicates that the TCI state corresponding to the first TRP is whether joint or separate, and a latter bit of the 2 bits indicates that the TCI state corresponding to the second TRP is whether joint or separate. In some embodiments, the MAC CE is further merged into another MAC CE, the another MAC CE is an unified TCI state activation/deactivation MAC CE.

Specifications and/or Discussions associated with Embodiment 1:

In current specification, for single TRP operation with unified TCI framework, one joint/DL TCI state list including M joint/DL TCI states and one UL TCI state list including N UL TCI states are configured within higher parameter PDSCH-Config and BWP-UplinkDedicated, respectively. A joint/DL TCI state provides a reference RS for determining QCL information for DL signals including PDSCH, PDCCH, CSI-RS and/or UL TX spatial filter for UL signals including PUSCH, PUCCH, SRS. A UL TCI state provides a reference RS for determining UL TX spatial filter. A unified TCI states activation/deactivation MAC CE selects several joint/DL TCI states from the joint/DL TCI state list and/or UL TCI states from the UL TCI state list to activate or deactivate. A TCI state filed in a DL DCI (e.g., DCI 1_1 and DCI 1_2) indicates one or two TCI states to apply.

In current specification, for multi-TRP operation without unified TCI framework, the signaling of DL beam indication and UL TX spatial filter is TCI state and spatial relation, respectively. Each DL and UL channel has its own TCI state list and spatial relation list, respectively. For example, a TCI state list for PDSCH and PDCCH is configured within higher parameters PDSCH-Config and PDCCH-Config, respectively. Similarly, a spatial relation list for PUCCH and SRS is configured within higher parameters PUCCH-Config and SRS-Config, respectively. Different MAC CEs are used for TCI state activation/deactivation for different channels. For PDCCH, enhanced TCI states indication for UE-specific PDCCH MAC CE is used. For PDSCH, (enhanced) TCI States Activation/Deactivation for UE-specific PDSCH MAC CE is used. For PUCCH, PUCCH spatial relation Activation/Deactivation for multiple TRP PUCCH repetition MAC CE is used. For PUSCH, the spatial relation is determined according to SRI filed in DCI. Specifically, A TCI state filed in a DL DCI (e.g., DCI 1_1 and DCI 1_2) indicates one or two TCI states to apply to PDSCH reception.

In Rel-18 WID, unified TCI framework are introduced for multi-TRP operation. To support multi-TRP, it is proposed two joint/DL TCI state list and two UL TCI state list are configured by RRC parameters. The first and second joint/DL TCI state lists include M1 and M2 joint/DL TCI states, respectively. The first and second UL TCI state lists include N1 and N2 UL TCI states, respectively. A joint/DL TCI state from the first and second joint/DL TCI state list provides a reference RS corresponding to the first and second TRP to determine QCL information and UL TX spatial filter corresponding to the first and second TRPs, respectively. A UL TCI state from the first and second UL TCI state list provides a reference RS corresponding to the first and second TRP to determine UL TX spatial filter corresponding to the first and second TRPs, respectively.

Examples associated with Embodiment 1:

In some examples, the legacy unified TCI states activation/deactivation MAC CE associated with different time units activates TCI states corresponding to different TRPs. At the odd time unit, the TCI states indicated by the TCI state ID fields are from the first joint/DL or UL TCI state list corresponding to the first TRP. At the even time unit, the TCI states indicated by the TCI state ID fields are from the second joint/DL or UL TCI state list corresponding to the second TRP. Therefore, network can activate TCI states corresponding to different TRPs individually by transmitting MAC CE at different time unit.

In some examples, the two legacy unified TCI states activation/deactivation MAC CEs can be transmitted simultaneously at a time unit. It is specific that the TCI states indicated by the TCI state ID fields in the former MAC CE are from the first joint/DL or UL TCI state list corresponding to the first TRP and the TCI states indicated by the TCI state ID fields in the latter MAC CE are from the second joint/DL or UL TCI state list corresponding to the second TRP. Therefore, network can activate TCI states corresponding to different TRPs simultaneously by transmitting MAC CE at the same time unit.

In some examples, one of the R fields (marked as T) in the legacy unified TCI states activation/deactivation MAC CE is used to indicate the association between a TCI state indicated by a TCI state ID filed and a TRP. If the T filed is ‘0’ , the TCI states indicated by the TCI state ID fields are from the first joint/DL or UL TCI state list corresponding to the first TRP. If the T filed is ‘1’ , the TCI states indicated by the TCI state ID fields are from the second joint/DL or UL TCI state list corresponding to the second TRP. Hence, network can activate TCI states corresponding to different TRPs individually by adjusting one of the T filed.

In some examples, a TCI state ID filed in the legacy unified TCI states activation/deactivation MAC CE is to activate up to two TCI states corresponding to different TRPs. One of these two TCI states indicated by the TCI state ID fields is from the first joint/DL or UL TCI state list corresponding to the first TRP. The other is from the second joint/DL or UL TCI state list corresponding to the second TRP. The TCI states corresponding to different TRPs do not need to activate simultaneously every time. Then, a new filed (marked as N) is added to indicate whether a TCI state ID filed actives one or two TCI state. If the number of TCI state indicated by a TCI state ID filed is one, an association between a TCI state and a TRP needs to be indicated. Then, a new filed (marked as T) is added to indicate TRP index. Hence, network can determine whether activate TCI states corresponding to different TRPs simultaneously or individually. FIG. 5 shows two examples of MAC CEs. In FIG. 5 (a) , all of TCI state ID fields share one N and T filed. In FIG. 5 (b) , each TCI state ID filed has corresponding one N and T filed.

Specifications and/or Discussions associated with Embodiment 2:

In current specification, for single TRP operation with unified TCI framework, unified TCI states activation/deactivation MAC CE is used to activate/deactivate joint/DL TCI states and/or UL TCI states. For simply, joint/DL TCI states and UL TCI states are collectively known as TCI states. The collection of these activated TCI states can be called an activated TCI state list. After activation of TCI states, a TCI filed (3 bits) in a DCI indicates TCI states from the activated TCI state list to apply to determining QCL information and/or UL TX spatial filter.

In Rel-18 WID, unified TCI framework is introduced for multi-TRP operation. Because of multi-TRP, two types of TCI states corresponding to two TRPs are activated by two MAC CEs or by two parts of one MAC CE, respectively. Hence, there are two activated TCI state lists corresponding to two TRPs, respectively. For single DCI based multi-TRP operation, only one TRP can transmit PDCCH such that there is only one DCI corresponding to one of TRPs at a time. Therefore, this one DCI needs to indicate two types of TCI states from the two activated TCI state list corresponding to different TRPs. Therefore, some mechanisms need to be introduced for a DCI to indicate two types of TCI states. It should be noted that the mechanisms can apply to not only single DCI based but also for multi-DCI based multi-TRP operation.

Examples associated with Embodiment 2:

In some examples, a DCI indicates TCI states once from an activated TCI state list corresponding to a TRP and the other DCI indicates TCI states from the other activated TCI state list corresponding to the other TRPs. These two DCIs can be located at different time unit. A UE distinguishes which DCI indicates TCI states corresponding to which TRP according to the time unit information. An example of this mechanism is shown in FIG. 6. The first MAC CE activates several TCI states corresponding to the first TRP. At the first time unit, UE receives the first DCI. If the TCI filed in the first DCI is ‘001’ , the first TCI state in the first activated TCI states corresponding to the first TRP is indicated. After the application time, a UE apply this new TCI state to receive DL signal (s) from the first TRP and transmitting UL signal (s) to the first TRP. The second MAC CE activates several TCI states corresponding to the second TRP. At the second time unit, UE receives the second DCI. If the TCI filed in the second DCI is ‘010’ , the third TCI state in the second activated TCI states corresponding to the second TRP is indicated. After the application time, a UE apply this new TCI state to receive DL signal (s) from the second TRP and transmitting UL signal (s) to the second TRP. By the way, the first and second time unit can be the odd and even slot, respectively.

In some examples, one DCI indicates TCI states from one activated TCI state list corresponding to one TRPs and TCI states from the other activated TCI state list corresponding to the other TRPs simultaneously. An example of this mechanism is shown in FIG. 7. The first MAC CE activates several TCI states corresponding to the first TRP. The second MAC CE activates several TCI states corresponding to the second TRP. At the first time point, UE receives the first DCI. If the TCI filed in the first DCI is ‘010, the third TCI state in the first activated TCI states corresponding to the first TRP and the third TCI state in the second activated TCI states corresponding to the second TRP is indicated. After the application time, a UE apply these two new TCI states to receive DL signal (s) from the first TRP and second TRP and transmitting UL signal (s) to the first TRP and second TRP.

In some examples, a TCI filed in a DCI is extended to 4 bits. The additive 1 bit is used to indicate TRP. This method is more flexible and explicit. An example of this mechanism is shown in FIG. 8. The first MAC CE activates several TCI states corresponding to the first TRP. At the first time point, UE receives the first DCI. If the TCI filed in the first DCI is ‘0001’ , the first TCI state in the first activated TCI states corresponding to the first TRP is indicated. After the application time, a UE apply this new TCI state to receive DL signal (s) from the first TRP and transmitting UL signal (s) to the first TRP. The second MAC CE activates several TCI states corresponding to the second TRP. At the second time point, UE receives the second DCI. If the TCI filed in the second DCI is ‘1010’ , the third TCI state in the second activated TCI states corresponding to the second TRP is indicated. After the application time, a UE apply this new TCI state to receive DL signal (s) from the second TRP and transmitting UL signal (s) to the second TRP.

In some examples, a TCI filed in a DCI is extended to 6 bits. The front 3 bits is used to indicate TCI states from one activated TCI state list corresponding to one TRP and the latter 3 bits is used to indicate TCI states from the other activated TCI state list corresponding to the other TRP. An example of this mechanism is shown in FIG. 9. The first MAC CE activates several TCI states corresponding to the first TRP. The second MAC CE activates several TCI states corresponding to the second TRP. At the first time point, UE receives the first DCI. If the TCI filed in the first DCI is ‘001010’ , the first TCI state in the first activated TCI states corresponding to the first TRP and the third TCI state in the second activated TCI states corresponding to the second TRP is indicated. After the application time, a UE apply these two new TCI states to receive DL signal (s) from the first TRP and second TRP and transmitting UL signal (s) to the first TRP and second TRP.

Specifications and/or Discussions associated with Embodiment 3:

In current specification, each UL channel is configured channel-specific spatial relation list and each UL channel has channel-specific MAC CE to select which spatial relation to apply. Specifically, spatial relation list for PUCCH is configured in higher parameters PUCCH-SpatialRelationInfo and (Enhanced) PUCCH spatial relation activation/deactivation MAC CE selects spatial relation to apply. For multi-TRP operation without unified TCI framework, a spatial relation is associated with a TRP such that a UE can know to transmit PUCCH to which TRP according to the applied spatial relation.

In Rel-18 WID, unified TCI framework is introduced for multi-TRP operation. For multi-TRP operation with unified TCI framework, a TCI state and an indicative MAC CE are not channel-specific. Generally, two TCI states corresponding to two TRPs are applied to UL transmission. A UE cannot know to transmit PUCCH to which TRP according to the applied TCI state. Therefore, some mechanisms need to be introduced to indicate PUCCH transmitted to which TRP. It should be noted that the mechanisms can be applied to the other UL signals such as PUSCH and SRS.

Examples associated with Embodiment 3:

In some examples, a TRP indicator for PUCCH filed with 1 bit added in DCI (e.g., DCI format 1_1, DCI format 1_2) can be used to indicate the association between a PUCCH resource and a TRP. The TRP indicator is an explicit TRP index or another index associated with TRP such as an index of the CORESET pool, an SRS resource set index, or a CSI-RS resource set index. When a UE receives the TRP indicator for PUCCH in DCI, the UE transmit the PUCCH indicated by DCI PUCCH resource indicator filed by using the TCI state corresponding to the TRP. For example, when the TRP indicator for PUCCH filed and the PUCCH resource indicator filed in DCI format 1_1 is ‘0’ and ‘000’ respectively, the UE transmits the first PUCCH by using the TCI state corresponding to the first TRP.

In some examples, a TRP indicator RRC signaling with 1 bit added in higher parameter PUCCH-Reousrce or PUCCH-ResourceSet can be used to indicate the association between a PUCCH resource or a PUCCH resource set and a TRP. The TRP indicator is an explicit TRP index, an index of the CORESET pool, an SRS resource set index, or a CSI-RS resource set index. When a UE receives the PUCCH resource indicator in DCI, the UE transmit the indicated PUCCH by using to TCI state corresponding to the TRP according to the TRP indicator RRC signaling in PUCCH-Resource or PUCCH-ResourceSet. For example, the TRP indicator RRC signaling is configured as ‘0’ in the first PUCCH resource and the PUCCH resource indicator filed in DCI format 1_1 is ‘000’ , the UE transmits the first PUCCH by using the TCI state corresponding to the first TRP.

In some examples, PUCCH resource or PUCCH resource sets can be associated with different TRPs implicitly. PUCCH resources or PUCCH resource sets can be divided into two parts and different parts are corresponding to different TRPs. FIG. 10 shows two classification methods. For example, the PUCCH resource indicator filed in DCI format 1_1 is ‘000’ , the UE transmits the first PUCCH by using the TCI state corresponding to the first TRP. The PUCCH resource indicator filed in DCI format 1_1 is ‘011’ , the UE transmits the fourth PUCCH by using the TCI state corresponding to the second TRP.

Specifications and/or Discussions associated with Embodiment 4:

In current specification, for single TRP operation with unified TCI framework, the switching between the joint TCI state and the separate TCI state is not dynamic which is configured by higher parameter unifiedtci-StateType.

Examples associated with Embodiment 4:

In some examples, for multi-TRP operation, it is proposed to extend this higher parameter to TRP-specific. For example, higher parameter unifiedtci-StateType-TRP1 indicate the first TRP is joint TCI state or separate TCI state and higher parameter unifiedtci-StateType-TRP2 indicate the second TRP is joint TCI state or separate TCI state.

In some examples, for multi-TRP operation, it is proposed to use MAC CE to support dynamic switching between the joint TCI state and the separate TCI state. For example, the MAC CE with 2 bits where the former bit indicates that the TCI state corresponding to the first TRP is whether joint or separate and the latter bit indicates that the TCI state corresponding to the second TRP is whether joint or separate. This MAC CE can also be merged into another MAC CE, such as unified TCI states activation/deactivation MAC CE.

In summary, some embodiments of the present disclosure provide some solutions to activating and indicating TCI states for multi-TRP operation with unified TCI framework. Two joint/DL or UL TCI state lists are established in RRC signaling. Different joint/DL or UL TCI state lists is corresponding to different TRPs. Several methods are proposed to activate TCI states from different TCI state lists corresponding to different TRPs. Several methods are proposed to indicate TCI states from different activated TCI state lists corresponding to different TRPs. Several methods are proposed to indicate which TRP the PUCCH is transmitted to. Advantages of some embodiments of the present disclosure include at least one of the followings. 1. Establishing two joint/DL or UL TCI state lists corresponding to different TRPs in RRC signaling. 2. Proposing several methods to activate TCI states from different TCI state lists corresponding to different TRPs. 3. Proposing several methods to indicate TCI states from different activated TCI state lists corresponding to different TRPs. 4. Proposing several methods to indicate which TRP the PUCCH is transmitted to.

FIG. 11 is a block diagram of an example system 700 for wireless communication according to an embodiment of the present disclosure. Embodiments described herein may be implemented into the system using any suitably configured hardware and/or software. FIG. 11 illustrates the system 700 including a radio frequency (RF) circuitry 710, a baseband circuitry 720, an application circuitry 730, a memory/storage 740, a display 750, a camera 760, a sensor 770, and an input/output (I/O) interface 780, coupled with each other at least as illustrated. The application circuitry 730 may include a circuitry such as, but not limited to, one or more single-core or multi-core processors. The processors may include any combination of general-purpose processors and dedicated processors, such as graphics processors, application processors. The processors may be coupled with the memory/storage and configured to execute instructions stored in the memory/storage to enable various applications and/or operating systems running on the system.

While the present disclosure has been described in connection with what is considered the most practical and preferred embodiments, it is understood that the present disclosure is not limited to the disclosed embodiments but is intended to cover various arrangements made without departing from the scope of the broadest interpretation of the appended claims.

Claims

A method for multiple-transmission reception point (multi-TRP) operation performed by a user equipment (UE) , comprising:

being configured with a first signaling from a network, wherein the first signaling is used for multi-TRP operation; and/or

receiving a second signaling from the network, wherein the second signaling is used for multi-TRP operation.
The method according to claim 1, wherein the first signaling configures different join/downlink (DL) or uplink (UL) transmission configuration indication (TCI) state lists corresponding to different TRPs and/or different joint/separate TCI state indications corresponding to the different TRPs; and/or

wherein the second signaling activates and/or indicates TCI states corresponding to the different TRPs and/or supports a switching between a joint TCI state and a separate TCI state.
The method according to claim 1 or 2, wherein the first signaling comprises a radio resource control (RRC) signaling, and the second signaling comprises a medium access control (MAC) control element (CE) , a downlink control information (DCI) , and/or a higher parameter.
The method according to claim 3, wherein the MAC CE comprises a legacy unified TCI state activation/deactivation MAC CE, the legacy unified TCI state activation/deactivation MAC CE is associated with different time units, and the legacy unified TCI state activation/deactivation MAC CE activates the TCI states corresponding to the different TRPs.
The method according to claim 4, wherein at an odd time unit, the TCI states indicated by TCI state identifier (ID) fields in the legacy unified TCI state activation/deactivation MAC CE are from a first joint/DL or UL TCI state list corresponding to a first TRP, and/or at an even time unit, the TCI states indicated by the TCI state ID fields are from a second joint/DL or UL TCI state list corresponding to a second TRP.
The method according to claim 3, wherein the MAC CE comprises a first legacy unified TCI state activation/deactivation MAC CE and a second legacy unified TCI state activation/deactivation MAC CE transmitted simultaneously at a time unit.
The method according to claim 6, wherein the TCI states indicated by TCI state ID fields in the first legacy unified TCI state activation/deactivation MAC CE are from a first joint/DL or UL TCI state list corresponding to a first TRP, and/or the TCI states indicated by the TCI state ID fields in the second legacy unified TCI state activation/deactivation MAC CE are from a second joint/DL or UL TCI state list corresponding to a second TRP.
The method according to any one of claims 4 to 7, wherein a first field of R fields in at least one of the legacy unified TCI state activation/deactivation MAC CE, the first the legacy unified TCI state activation/deactivation MAC CE, and the second the legacy unified TCI state activation/deactivation MAC CE is used to indicate an association between one TCI state indicated by one TCI state ID filed and one TRP.
The method according to claim 8, wherein if a first field of R fields indicates a first value, the TCI states indicated by the TCI state ID fields are from the first joint/DL or UL TCI state list corresponding to the first TRP, and/or if the first field of R fields indicates a second value, the TCI states indicated by the TCI state ID fields are from the second joint/DL or UL TCI state list corresponding to the second TRP.
The method according to any one of claims 4 to 9, wherein one TCI state ID filed in at least one of the legacy unified TCI state activation/deactivation MAC CE, the first the legacy unified TCI state activation/deactivation MAC CE, and the second the legacy unified TCI state activation/deactivation MAC CE is used to activate up to two TCI states corresponding to the different TRPs.
The method according to claim 10, wherein a second field of R fields in at least one of the legacy unified TCI state activation/deactivation MAC CE, the first the legacy unified TCI state activation/deactivation MAC CE, and the second the legacy unified TCI state activation/deactivation MAC CE is used to indicate whether one TCI state ID filed actives one or two TCI states.
The method according to claim 11, wherein if a number of the TCI state indicated by the one TCI state ID filed is one, the association between the TCI state and the TRP is indicated by the first field of R fields.
The method according to claim 12, wherein the first field of R fields is further used to indicate a TRP index.
The method according to any one of claims 4 to 13, wherein in at least one of the legacy unified TCI state activation/deactivation MAC CE, the first the legacy unified TCI state activation/deactivation MAC CE, and the second the legacy unified TCI state activation/deactivation MAC CE, all of TCI state ID fields share the first field of R fields and the second field of R fields, or each TCI state ID filed has the first field of R fields and the second field of R fields.
The method according to claim 3, wherein the DCI comprises a first DCI and a second DCI, the first DCI indicates the TCI states from an activated TCI state list corresponding to one TRP and the second DCI indicates the TCI states from another activated TCI state list corresponding to another TRP.
The method according to claim 15, wherein the first DCI and the second DCI are located at different time units.
The method according to claim 3, wherein the DCI indicates the TCI states from an activated TCI state list corresponding to one TRP, and the DCI indicates the TCI states from another activated TCI state list corresponding to another TRP simultaneously.
The method according to claim 3, wherein one TCI filed in the DCI is extended to 4 bits, an additive 1 bit of the 4 bits is used to indicate the TRP.
The method according to claim 3, wherein one TCI filed in the DCI is extended to 6 bits, front 3 bits of the 6 bits are used to indicate the TCI states from the one activated TCI state list corresponding to the one TRP, and latter 3 bits of the 6 bits are used to indicate the TCI states from the another activated TCI state list corresponding to the another TRP.
The method according to claim 3, wherein the DCI comprises a DL DCI, a TRP indicator for a physical uplink control channel (PUCCH) filed with 1 bit added in the DL DCI is used to indicate an association between a PUCCH resource and one TRP.
The method according to claim 20, wherein when the UE receives the TRP indicator for the PUCCH field in the DL DCI, the UE transmits a PUCCH indicated by the PUCCH field by using one TCI state corresponding to the TRP.
The method according to claim 3, wherein the higher parameter comprises PUCCH-Reousrce or PUCCH-ResourceSet, a TRP indicator RRC signaling with 1 bit added in the higher parameter is used to indicate an association between a PUCCH resource or a PUCCH resource set and one TRP.
The method according to claim 22, wherein when the UE receives a PUCCH resource indicator in the DCI, the UE transmits an indicated PUCCH by using the TCI state corresponding to the TRP according to the TRP indicator RRC signaling in the higher parameter.
The method according to claim 23, wherein PUCCH resources or PUCCH resource sets are associated with the different TRPs, and/or the PUCCH resources or the PUCCH resource sets are divided into different parts, and the different parts are corresponding to the different TRPs.
The method according to claim 3, wherein the higher parameter is extended to TRP-specific.
The method according to claim 25, wherein the higher parameter comprises unifiedtci-StateType-TRP1 and unifiedtci-StateType-TRP2, the unifiedtci-StateType-TRP1 indicates that the first TRP is the joint TCI state or the separate TCI state, and the unifiedtci-StateType-TRP2 indicates that the second TRP is the joint TCI state or the separate TCI state.
The method according to claim 3, wherein for multi-TRP operation, the MAC CE is used to support a dynamic switching between the joint TCI state and the separate TCI state.
The method according to claim 27, wherein the MAC CE has 2 bits, where a former bit of the 2 bits indicates that the TCI state corresponding to the first TRP is whether joint or separate, and a latter bit of the 2 bits indicates that the TCI state corresponding to the second TRP is whether joint or separate.
The method according to claim 27 or 28, wherein the MAC CE is further merged into another MAC CE, the another MAC CE is an unified TCI state activation/deactivation MAC CE.
A method for multiple-transmission reception point (multi-TRP) operation performed by a network, comprising:

configuring a first signaling to a user equipment (UE) , wherein the first signaling is used for multi-TRP operation; and/or

transmitting a second signaling to the UE, wherein the second signaling is used for multi-TRP operation.
A user equipment, comprising:

a memory;

a transceiver; and

a processor coupled to the memory and the transceiver;

wherein the processor is configured to execute the method of any one of claims 1 to 29.
A network, comprising:

a memory;

a transceiver; and

a processor coupled to the memory and the transceiver;

wherein the processor is configured to execute the method of claim 30.
A non-transitory machine-readable storage medium having stored thereon instructions that, when executed by a computer, cause the computer to perform the method of any one of claims 1 to 30.
A chip, comprising:

a processor, configured to call and run a computer program stored in a memory, to cause a device in which the chip is installed to execute the method of any one of claims 1 to 30.
A computer readable storage medium, in which a computer program is stored, wherein the computer program causes a computer to execute the method of any one of claims 1 to 30.
A computer program product, comprising a computer program, wherein the computer program causes a computer to execute the method of any one of claims 1 to 30.
A computer program, wherein the computer program causes a computer to execute the method of any one of claims 1 to 30.