Default spatial relationship of PUCCH and SRS with multi-TRP

Abstract

Systems, devices, and methods are described that enable multi-TRP operation with a single DCI and with multiple DCIs. A single DCI or multiple DCIs for the TRP are used for PUCCH and SRS transmissions. A spatial relationship between CORESET reception and PUCCH transmission or between SRS repetitions is provided. The association of PUCCH transmissions depends on whether a single spatial relationship or multiple spatial relationships are used. The associations are default, explicit, and implicit associations between TRPs and CORESET or TCI states.

Description

[Technical Field]

[0001] [Priority Claim] This application claims the benefit of priority to International Application No. PCT / CN2020 / 102652, filed July 17, 2020, and International Application No. PCT / CN2020 / 102853, filed July 17, 2020, each of which is incorporated herein by reference in its entirety.

[0002] Embodiments relate to wireless communication in a fifth generation (5G) New Radio (NR) system. Some embodiments relate to multiple transmit / receive point (TRP) operation in a 5G system. [Background technology]

[0003] The use and complexity of 3GPP® LTE systems (including LTE and LTE-Advanced systems) is increasing due to both the increasing types of device user equipment (UE) using network resources and the increasing amount of data and bandwidth used by various applications, such as video streams, running on these UEs. Due to the enormous increase in the number and diversity of communicating devices, the corresponding network environment, including routers, switches, bridges, gateways, firewalls, and load balancers, is becoming increasingly complex, especially with the advent of 5G systems. As expected, numerous problems arise with the emergence of any new technology. [Brief explanation of the drawings]

[0004] In the figures, which are not necessarily drawn to scale, like reference numbers may describe like components in different figures. Like reference numbers with different subscripts may represent different instances of like components. The figures generally illustrate various embodiments described herein by way of example, not limitation.

[0005] [Figure 1A]1 illustrates a network architecture in accordance with some aspects.

[0006] [Figure 1B] 1 illustrates a non-roaming 5G system architecture in accordance with some aspects.

[0007] [Figure 1C] 1 illustrates a non-roaming 5G system architecture in accordance with some aspects.

[0008] [Figure 2] 1 illustrates a block diagram of a communication device according to some embodiments.

[0009] [Figure 3A] 1 illustrates a single downlink control information (DCI) TRP operation according to some embodiments.

[0010] [Figure 3B] 1 illustrates multi-DCI TRP operation according to some embodiments.

[0011] [Figure 4] 1 illustrates a Medium Access Control (MAC) Control Element (MAC-CE) according to some embodiments.

[0012] [Figure 5] 1 illustrates a MAC-CE for updating spatial relationships of semi-persistent sounding reference signals (SRS) according to some embodiments.

[0013] [Figure 6] 1 illustrates a MAC-CE for updating spatial relationships of aperiodic SRS according to some embodiments.

[0014] [Figure 7] 1 illustrates a default spatial relationship determination for a physical uplink control channel (PUCCH) according to some embodiments.

[0015] [Figure 8] 1 illustrates a PUCCH default spatial relationship based on Control Resource Set (CORESET) Transmission Configuration Indicator (TCI) state and TRP according to some embodiments.

[0016] [Figure 9] 10 illustrates another PUCCH default spatial relationship based on CORESET TCI state and TRP according to some embodiments.

[0017] [Figure 10] 1 illustrates an example of an association between a TRP and a TCI state according to some embodiments.

[0018] [Figure 11] 10 illustrates an example of a PUCCH default spatial relationship with implicit association according to some embodiments.

[0019] [Figure 12] 10 illustrates another example of a PUCCH default spatial relationship with implicit association according to some embodiments.

[0020] [Figure 13] 10 illustrates an example of a PUCCH default spatial relationship with explicit association according to some embodiments.

[0021] [Figure 14] 10 illustrates another example of a PUCCH default spatial relationship with explicit association according to some embodiments.

[0022] [Figure 15] 10 illustrates another example of a PUCCH default spatial relationship with explicit association according to some embodiments.

[0023] [Figure 16] 10 illustrates another example of a PUCCH with multiple spatial relationships in accordance with some embodiments.

[0024] [Figure 17] 10 illustrates another example of a PUCCH with multiple spatial relationships in accordance with some embodiments.

[0025] [Figure 18] 10 illustrates another example of a PUCCH with multiple spatial relationships in accordance with some embodiments.

[0026] [Figure 19] 10 illustrates another example of a PUCCH with multiple spatial relationships in accordance with some embodiments.

[0027] [Figure 20] 10 illustrates another example of a PUCCH with multiple spatial relationships in accordance with some embodiments.

[0028] [Figure 21(a)] 1 illustrates an example of an SRS with multiple spatial relationships with sequential mapping in accordance with some embodiments.

[0029] [Figure 21(b)] 1 illustrates an example of an SRS with multiple spatial relationships with periodic mapping according to some embodiments.

[0030] [Figure 22] 1 illustrates an example of a semi-persistent SRS activation / deactivation MAC CE with multiple spatial relationships according to some embodiments.

[0031] [Figure 23] 1 illustrates an example of an aperiodic SRS spatial relationship indication MAC CE according to some embodiments.

[0032] [Figure 24] 10 illustrates an example of SRS default spatial relationships with CORESET according to some embodiments.

[0033] [Figure 25] 10 illustrates an example of SRS default spatial relationships by CORESET TCI state and TRP according to some embodiments.

[0034] [Figure 26] 10 illustrates another example of SRS default spatial relationships according to CORESET TCI states and TRPs in accordance with some embodiments.

[0035] [Figure 27] 1 illustrates an example of an implicit association between a TCI state and a TRP according to some embodiments.

[0036] [Figure 28] 10 illustrates an example of an SRS default spatial relationship with an implicit association between a TCI and a TRP according to some embodiments.

[0037] [Figure 29] 10 illustrates another example of an SRS default spatial relationship with an implicit association between a TCI and a TRP according to some embodiments.

[0038] [Figure 30] 1 illustrates an example of an explicit association between a TCI state and a TRP according to some embodiments.

[0039] [Figure 31] 10 illustrates an example of an SRS default spatial relationship with explicit association between TCI and TRP according to some embodiments.

[0040] [Figure 32] 10 illustrates another example of an SRS default spatial relationship with an explicit association between a TCI and a TRP according to some embodiments.

[0041] [Figure 33] 1 illustrates an example of an SRS with multiple spatial relationships determined by associations between CORESETs and TRPs according to some embodiments.

[0042] [Figure 34] 1 illustrates an example of an SRS with multiple spatial relationships determined by associations between CORESET TCIs and TRPs according to some embodiments.

[0043] [Figure 35] 10 illustrates another example of an SRS with multiple spatial relationships determined by associations between CORESET TCIs and TRPs according to some embodiments.

[0044] [Figure 36] 1 illustrates an example of an SRS with multiple spatial relationships determined by associations between TCIs and TRPs according to some embodiments.

[0045] [Figure 37] 10 illustrates another example of an SRS with multiple spatial relationships determined by associations between TCIs and TRPs according to some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0046] The following description and drawings sufficiently illustrate specific embodiments to enable those skilled in the art to practice the embodiments. Other embodiments may incorporate structural, logical, electrical, process, and other changes. Portions and features of some embodiments may be included in, or substituted for, portions and features of other embodiments. The claimed embodiments encompass all available equivalents of such claims.

[0047] 1A illustrates a network architecture in accordance with some aspects. Network 140A includes 3GPP LTE / 4G and NG network functions. The network functions can be implemented as discrete network elements on dedicated hardware, as software instances running on dedicated hardware, and / or as virtualized functions instantiated on a suitable platform, such as dedicated hardware or a cloud infrastructure.

[0048] Network 140A is shown to include user equipment (UE) 101 and UE 102. UEs 101 and 102 are shown as smartphones (e.g., handheld touchscreen mobile computing devices capable of connecting to one or more cellular networks), but may include any mobile or non-mobile computing device, such as a portable (laptop) or desktop computer, a wireless handset, a drone, or any other computing device that includes a wired and / or wireless communication interface. UEs 101 and 102 may be collectively referred to herein as UE 101, and UE 101 may be used to perform one or more of the techniques disclosed herein.

[0049] Any of the wireless links described herein (e.g., used in network 140A or any other illustrated network) may operate according to any exemplary wireless communication technology and / or standard. Any spectrum management scheme may be used, including, for example, dedicated licensed spectrum, unlicensed spectrum, or (licensed) shared spectrum (such as Licensed Shared Access (LSA) at 2.3-2.4 GHz, 3.4-3.6 GHz, 3.6-3.8 GHz, and other frequencies, and Spectrum Access System (SAS) at 3.55-3.7 GHz and other frequencies). Different single-carrier or orthogonal frequency domain multiplexing (OFDM) modes (CP-OFDM, SC-FDMA, SC-OFDM, filter bank-based multicarrier (FBMC), OFDMA, etc.), particularly 3GPP NR, may be used by assigning OFDM carrier data bit vectors to corresponding symbol resources.

[0050] In some aspects, either of the UEs 101 and 102 may comprise an Internet of Things (IoT) UE or a Cellular IoT (CIoT) UE, which may include a network access layer designed for low-power IoT applications utilizing short-lived UE connections. In some aspects, either of the UEs 101 and 102 may comprise a Narrowband (NB) IoT UE (e.g., enhanced NB-IoT (eNB-IoT) UE and enhanced FeNB-IoT UE, etc.). The IoT UE may utilize technologies such as public land mobile network (PLMN), proximity-based services (ProSe) or device-to-device (D2D) communications, sensor networks, or machine-to-machine (M2M) or machine-type communications (MTC) to exchange data with an MTC server or device over an IoT network. The M2M or MTC exchange of data may be a machine-initiated exchange of data. The IoT network includes interconnecting IoT UEs, which may include uniquely identifiable embedded computing devices (within the Internet infrastructure), over short-lived connections. The IoT UE may run background applications (e.g., keep-alive messages, status updates, etc.) to facilitate IoT network connectivity. In some aspects, either of the UEs 101 and 102 may include an enhanced MTC (eMTC) UE or a supplemental enhanced MTC (FeMTC) UE.

[0051] The UEs 101 and 102 may be configured to be connected, e.g., communicatively coupled, to a radio access network (RAN) 110. The RAN 110 may be, for example, an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN), a NextGen RAN (NG RAN), or some other type of RAN.

[0052] UEs 101 and 102 utilize connections 103 and 104, respectively, each of which includes a physical communication interface or layer (described in further detail below), which in this example are shown as radio interfaces for enabling a communicative coupling and may be compatible with cellular communication protocols such as the Global System for Mobile Communications (GSM) protocol, a Code Division Multiple Access (CDMA) network protocol, a Push-to-Talk (PTT) protocol, a PTT over Cellular (POC) protocol, a Universal Mobile Telecommunications System (UMTS) protocol, a 3GPP Long Term Evolution (LTE) protocol, a Fifth Generation (5G) protocol, a New Radio (NR) protocol, etc.

[0053] In an aspect, the UEs 101 and 102 may further directly exchange communication data via the ProSe interface 105. The ProSe interface 105 may alternatively be referred to as a sidelink (SL) interface, which includes one or more logical channels, including, but not limited to, a physical sidelink control channel (PSCCH), a physical sidelink shared channel (PSSCH), a physical sidelink discovery channel (PSDCH), a physical sidelink broadcast channel (PSBCH), and a physical sidelink feedback channel (PSFCH).

[0054] The UE 102 is shown as configured to access an access point (AP) 106 via a connection 107. The connection 107 may include, for example, a local wireless connection, such as a connection consistent with any IEEE 802.11 protocol, according to which the AP 106 may include a Wireless Fidelity (WiFi) router. In this example, the AP 106 is shown as being connected to the Internet without being connected to a core network of a wireless system (described in more detail below).

[0055] The RAN 110 may include one or more access nodes that enable the connections 103 and 104. These access nodes (ANs) may be referred to as base stations (BSs), NodeBs, evolved NodeBs (eNBs), next-generation NodeBs (gNBs), RAN nodes, etc., and may include earth stations (e.g., terrestrial access points) or satellite stations that provide coverage within a geographic area (e.g., a cell). In some aspects, the communication nodes 111 and 112 may be transmit / receive points (TRPs). When the communication nodes 111 and 112 are NodeBs (e.g., eNBs or gNBs), one or more TRPs may function within the communication cell of the NodeB. The RAN 110 may include one or more RAN nodes for providing a macrocell, e.g., a macro RAN node 111, and one or more RAN nodes for providing a femtocell or picocell (e.g., a cell having a smaller coverage area, smaller user capacity, or higher bandwidth compared to a macrocell), e.g., a low-power (LP) RAN node 112.

[0056] Either of the RAN nodes 111 and 112 may terminate air interface protocols and may be the first point of contact for the UEs 101 and 102. In some aspects, either of the RAN nodes 111 and 112 may perform various logical functions for the RAN 110, including, but not limited to, radio bearer management, uplink and downlink dynamic radio resource management and data packet scheduling, and radio network controller (RNC) functions such as mobility management. In examples, either of the nodes 111 and / or 112 may be a gNB, an eNB, or another type of RAN node.

[0057] The RAN 110 is shown as communicatively coupled to a core network (CN) 120 via an S1 interface 113. In an aspect, the CN 120 may be an evolved packet core (EPC) network, a next-generation packet core (NPC) network, or some other type of CN (e.g., as shown with reference to FIGS. 1B-1C ). In this aspect, the S1 interface 113 is divided into two parts: an S1-U interface 114 that carries traffic data between the RAN nodes 111 and 112 and a serving gateway (S-GW) 122, and an S1-mobility management entity (MME) interface 115 that is a signaling interface between the RAN nodes 111 and 112 and the MME 121.

[0058] In this aspect, the CN 120 includes an MME 121, an S-GW 122, a packet data network (PDN) gateway (P-GW) 123, and a home subscriber server (HSS) 124. The MME 121 may be similar in function to the control plane of a legacy Serving General Packet Radio Service (GPRS) Support Node (SGSN). The MME 121 may manage mobility aspects during access, such as gateway selection and tracking area list management. The HSS 124 may include a database of network users containing subscription-related information to support network entity handling of communication sessions. The CN 120 may include one or several HSSs 124s, depending on the number of mobile subscribers, equipment capabilities, network organization, etc. For example, the HSS 124 may provide support for routing / roaming, authentication, authorization, naming / addressing resolution, location dependency, etc.

[0059] The S-GW 122 may terminate the S1 interface 113 towards the RAN 110 and route data packets between the RAN 110 and the CN 120. Additionally, the S-GW 122 may be a local mobility anchor point for inter-RAN node handovers and may also provide an anchor for inter-3GPP mobility. Other roles of the S-GW 122 may include lawful interception, charging, and some policy enforcement.

[0060] The P-GW 123 may terminate the SGi interface toward the PDN. The P-GW 123 may route data packets between the EPC network 120 and external networks, such as a network including an application server 184 (alternatively referred to as an application function (AF)), via an Internet Protocol (IP) interface 125. The P-GW 123 may also communicate data to other external networks 131A, which may include the Internet, an IP Multimedia Subsystem (IPS) network, and other networks. Generally, the application server 184 may be an element providing applications (e.g., a UMTS packet service (PS) domain, an LTE PS data service, etc.) that use IP bearer resources with the core network. In this aspect, the P-GW 123 is shown as communicatively coupled to the application server 184 via the IP interface 125. The application server 184 may also be configured to support one or more communication services (e.g., a voice over Internet Protocol (VoIP) session, a PTT session, a group communication session, a social networking service, etc.) for the UEs 101 and 102 via the CN 120.

[0061] The P-GW 123 may further be a policy enforcement and charging data collection node. The Policy and Charging Rules Function (PCRF) 126 is the policy and charging control element of the CN 120. In a non-roaming scenario, in some aspects, there may be a single PCRF in a Home Public Land Mobile Network (HPLMN) associated with the UE's Internet Protocol Connectivity Access Network (IP-CAN) session. In a roaming scenario with local breakout of traffic, there may be two PCRFs associated with the UE's IP-CAN session: a Home PCRF (H-PCRF) in the HPLMN and a Visited PCRF (V-PCRF) in a Visited Public Land Mobile Network (VPLMN). The PCRF 126 may be communicatively coupled to the application server 184 via the P-GW 123.

[0062] In some aspects, the communications network 140A may be an IoT network or a 5G network, including a 5G New Radio Network using communications in licensed (5G NR) and unlicensed (5G NR-U) spectrum. One of the current enablers of IoT is narrowband IoT (NB-IoT). Operation in unlicensed spectrum may include dual connectivity (DC) operation in unlicensed spectrum and standalone LTE systems, according to which LTE-based technologies operate exclusively in unlicensed spectrum without the use of an "anchor" in licensed spectrum, referred to as MuLTEFire. Further enhanced operation of LTE systems in licensed and unlicensed spectrum is expected in future releases and 5G systems. Such enhanced operation may include techniques for sidelink resource allocation and UE processing behavior for NR sidelink V2X communications.

[0063] The NG system architecture may include a RAN 110 and a 5G network core (5GC) 120. The NG-RAN 110 may include multiple nodes such as a gNB and an NG-eNB. The core network 120 (e.g., a 5G core network or 5GC) may include an access and mobility function (AMF) and / or a user plane function (UPF). The AMF and UPF may be communicatively coupled to the gNB and the NG-eNB via an NG interface. More specifically, in some aspects, the gNB and the NG-eNB may be connected to the AMF by an NG-C interface and to the UPF by an NG-U interface. The gNB and the NG-eNB may be coupled to each other via an Xn interface.

[0064] In some aspects, the NG system architecture can use reference points between various nodes provided by 3GPP Technical Specification (TS) 23.501 (e.g., V15.4.0, 2018-12). In some aspects, each of the gNB and NG-eNB can be implemented as a base station, a mobile edge server, a small cell, a home eNB, and so on. In some aspects, the gNB can be a master node (MN), and the NG-eNB can be a secondary node (SN) in the 5G architecture.

[0065] 1B illustrates a non-roaming 5G system architecture in accordance with some aspects. In particular, FIG. 1B illustrates a 5G system architecture 140B in a reference point representation. More specifically, a UE 102 can communicate with a RAN 110 and one or more other 5G network entities. The 5G system architecture 140B includes multiple network functions (NFs), such as an AMF 132, a session management function (SMF) 136, a policy control function (PCF) 148, an application function (AF) 150, a UPF 134, a network slice selection function (NSSF) 142, an authentication server function (AUSF) 144, and a unified data management (UDM) / home subscriber server (HSS) 146.

[0066] The UPF 134 can provide connectivity to the data network (DN) 152, which may include, for example, operator services, Internet access, or third-party services. The AMF 132 can be used to manage access control and mobility and may also include network slice selection functionality. The AMF 132 may provide UE-based authentication, authorization, mobility management, etc., and may be independent of access technology. The SMF 136 can be configured to set up and manage various sessions according to network policies. Thus, the SMF 136 may be responsible for session management and assigning IP addresses to UEs. The SMF 136 may also select and control the UPF 134 for data transfer. The SMF 136 may be associated with a single session of the UE 101 or multiple sessions of the UE 101. That is, the UE 101 may have multiple 5G sessions. A different SMF may be assigned to each session. The use of different SMFs may allow each session to be managed individually. As a result, the functionality of each session may be independent of each other.

[0067] The UPF 134 can be deployed in one or more configurations according to the desired service type and can be connected to a data network. The PCF 148 can be configured to provide a policy framework using network slicing, mobility management, and roaming (similar to a PCRF in a 4G communication system). The UDM can be configured to store subscriber profiles and data (similar to an HSS in a 4G communication system).

[0068] The AF 150 may provide information about packet flows to the PCF 148, which is responsible for policy control to support the desired QoS. The PCF 148 may configure mobility and session management policies for the UE 101. To this end, the PCF 148 may use the packet flow information to determine appropriate policies for the appropriate operation of the AMF 132 and SMF 136. The AUSF 144 may store data for UE authentication.

[0069] In some aspects, the 5G system architecture 140B includes multiple IP multimedia core network subsystem entities, such as an IP multimedia subsystem (IMS) 168B and a call session control function (CSCF). More specifically, the IMS 168B includes a CSCF, which can operate as a proxy CSCF (P-CSCF) 162B, a serving CSCF (S-CSCF) 164B, an emergency CSCF (E-CSCF) (not shown in FIG. 1B), or an interrogate CSCF (I-CSCF) 166B. The P-CSCF 162B can be configured to be the first point of contact for the UE 102 within the IM subsystem (IMS) 168B. The S-CSCF 164B can be configured to handle session state in the network, and the E-CSCF can be configured to handle certain aspects of the emergency session, such as routing the emergency request to the correct emergency center or PSAP. The I-CSCF 166B can be configured to serve as the point of contact within an operator's network for all IMS connections destined for that network operator's subscribers or roaming subscribers currently located within the network operator's service area. In some aspects, the I-CSCF 166B can be connected to another IP multimedia network 170E, e.g., an IMS operated by a different network operator.

[0070] In some aspects, the UDM / HSS 146 can be coupled to an application server 160E, which can include a telephony application server (TAS) or another application server (AS). The AS 160B can be coupled to the IMS 168B via the S-CSCF 164B or the I-CSCF 166B.

[0071] The reference point representation indicates that interactions may exist between corresponding NF services. For example, Figure 1B shows the following reference points: N1 (between the UE 102 and the AMF 132), N2 (between the RAN 110 and the AMF 132), N3 (between the RAN 110 and the UPF 134), N4 (between the SMF 136 and the UPF 134), N5 (between the PCF 148 and the AF 150, not shown), N6 (between the UPF 134 and the DN 152), N7 (between the SMF 136 and the PCF 148, not shown), N8 (between the UDM 146 and the AMF 132, not shown), N9 (between two UPFs 134, not shown), N10 (between the UDM 146 and the SMF 136, not shown), 1B shows N11 (between the AMF 132 and the SMF 136, not shown), N12 (between the AUSF 144 and the AMF 132, not shown), N13 (between the AUSF 144 and the UDM 146, not shown), N14 (between two AMFs 132, not shown), N15 (between the PCF 148 and the AMF 132 in the case of a non-roaming scenario, or between the PCF 148, the visited network, and the AMF 132 in the case of a roaming scenario, not shown), N16 (between two SMFs, not shown), and N22 (between the AMF 132 and the NSSF 142, not shown). Other reference point representations not shown in FIG. 1B may also be used.

[0072] 1C illustrates a 5G system architecture 140C and a service-based representation. In addition to the network entities illustrated in FIG. 1B, the system architecture 140C may also include a network exposure function (NEF) 154 and a network repository function (NRF) 156. In some aspects, the 5G system architecture may be service-based, and interactions between network functions may be represented by corresponding point-to-point reference points N or service-based interfaces.

[0073] 1C , the 5G system architecture 140C may include the following service-based interfaces: Namf 158H (service-based interface indicated by AMF 132), Nsmf 158I (service-based interface indicated by SMF 136), Nnef 158B (service-based interface indicated by NEF 154), Npcf 158D (service-based interface indicated by PCF 148), Nudm 158E (service-based interface indicated by UDM 146), Naf 158F (service-based interface indicated by AF 150), Nnrf 158C (service-based interface indicated by NRF 156), Nnssf 158A (service-based interface indicated by NSSF 142), and Nausf 158G (service-based interface indicated by AUSF 144). Other service-based interfaces not shown in FIG. 1C (eg, Nudr, N5g-eir, and Nudsf) may also be used.

[0074] The NR-V2X architecture can support reliable, low-latency sidelink communications with a variety of traffic patterns, including periodic and aperiodic communications with random packet arrival times and sizes. The techniques disclosed herein can be used to support high reliability in distributed communication systems with dynamic topologies, including sidelink NR V2X communication systems.

[0075] 2 illustrates a block diagram of a communications device according to some embodiments. Communications device 200 may be dedicated network equipment such as a dedicated computer, a personal or laptop computer (PC), a UE such as a tablet PC or smartphone, an eNB, software running on a server to configure the server to operate as a network device, a virtual device, or any machine capable of executing instructions (sequentially or otherwise) specifying actions to be performed by that machine. For example, communications device 200 may be implemented as one or more of the devices shown in FIGS. 1A through 1C. Note that communications described herein may be encoded prior to transmission by transmitting entities (e.g., UE, gNB) for reception by the receiving entity (e.g., gNB, UE) and decoded after reception by the receiving entity.

[0076] As described herein, examples may include or operate on logic or multiple components, modules, or mechanisms. Modules and components are tangible entities (e.g., hardware) capable of performing specific operations and may be configured or arranged in a specific manner. In examples, circuits may be configured in a specific manner (e.g., internally or with respect to external entities such as other circuits) as modules. In examples, all or part of one or more computer systems (e.g., standalone, client, or server computer systems) or one or more hardware processors may be configured by firmware or software (e.g., instructions, application portions, or applications) as modules that operate to perform specific operations. In examples, software may reside on a machine-readable medium. In examples, software, when executed by underlying hardware of modules, causes the hardware to perform specific operations.

[0077] Thus, the terms "module" (and "component") are understood to encompass tangible entities that are physically constructed entities, specifically configured (e.g., hardwired) or temporarily (e.g., transiently) configured (e.g., programmed) to operate in a particular manner or to perform some or all of the operations described herein. Considering examples where modules are temporarily configured, each of the modules need not be instantiated at any one time. For example, if the modules include a general-purpose hardware processor that is configured using software, the general-purpose hardware processor may be configured as different modules at different times. Thus, the software may configure the hardware processor, for example, to configure a particular module at one time and another module at a different time.

[0078] The communications device 200 may include a hardware processor (or equivalent processing circuitry) 202 (e.g., a central processing unit (CPU), a GPU, a hardware processor core, or any combination thereof), a main memory 204, and a static memory 206, some or all of which may be in communication with each other via an interlink (e.g., a bus) 208. The main memory 204 may include any or all of removable and non-removable storage, volatile memory, or non-volatile memory. The communications device 200 may further include a display unit 210, such as a video display, an alphanumeric input device 212 (e.g., a keyboard), and a user interface (UI) navigation device 214 (e.g., a mouse). In an example, the display unit 210, the input device 212, and the UI navigation device 214 may be touchscreen displays. Communications device 200 may additionally include a storage device (e.g., a drive unit) 216, a signal generating device 218 (e.g., a speaker), a network interface device 220, and one or more sensors, such as a global positioning system (GPS) sensor, a compass, an accelerometer, or other sensor. Communications device 200 may further include an output controller, such as a serial (e.g., Universal Serial Bus (USB), parallel, or other wired or wireless (e.g., infrared (IR), near field communication (NFC), etc.) connection, for communicating with or controlling one or more peripheral devices (e.g., a printer, a card reader, etc.).

[0079] Storage device 216 may include a non-transitory machine-readable medium 222 (hereinafter simply referred to as machine-readable medium) that stores one or more data structures or sets of instructions 224 (e.g., software) embodied in or utilized by any one or more of the techniques or functions described herein. The instructions 224 may reside, completely or at least partially, within main memory 204, static memory 206, and / or hardware processor 202 during execution thereof by communications device 200. While machine-readable medium 222 is depicted as a single medium, the term "machine-readable medium" may include a single medium or multiple media (e.g., a centralized or distributed database, and / or associated caches and servers) configured to store one or more instructions 224.

[0080] The term "machine-readable medium" may include any medium capable of storing, encoding, or carrying instructions for execution by communication device 200 and causing communication device 200 to perform any one or more of the techniques of this disclosure, or any medium capable of storing, encoding, or carrying data structures used by or associated with such instructions. Non-limiting examples of machine-readable media may include solid-state memories and optical / magnetic media. Specific examples of machine-readable media may include non-volatile memory, such as semiconductor memory devices (e.g., electrically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM)) and flash memory devices, magnetic disks, such as internal hard disks and removable disks, optical / magnetic disks, wireless access memory (RAM), and CD-ROM and DVD-ROM disks.

[0081] The instructions 224 may further be transmitted or received over a communications network using a transmission medium 226 via a network interface device 220 utilizing any one of a number of wireless local area network (WLAN) transport protocols (e.g., Frame Relay, Internet Protocol (IP), Transmission Control Protocol (TCP), User Datagram Protocol (UDP), Hypertext Transfer Protocol (HTTP), etc.). Exemplary communications networks may include a local area network (LAN), a wide area network (WAN), a packet data network (e.g., the Internet), a mobile telephone network (e.g., a cellular network), a plain old telephone (POTS) network, and a wireless data network. Communications over the network may include one or more different protocols, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards known as Wi-Fi®, the IEEE 802.16 family of standards known as WiMAX®, the IEEE 802.15.4 family of standards, the Long Term Evolution (LTE) family of standards, the Universal Mobile Telecommunications System (UMTS) family of standards, peer-to-peer (P2P) networks, next generation (NG) / fifth generation (5G) standards, among others. In an example, the network interface device 220 may include one or more physical jacks (e.g., Ethernet, coaxial, or phone jack) or one or more antennas to connect to the transmission medium 226.

[0082] It should be noted that, as used herein, the term “circuitry” refers to, is a part of, or includes hardware components such as electronic circuits, logic circuits, processors (shared, dedicated, or group) and / or memories (shared, dedicated, or group), application-specific integrated circuits (ASICs), field programmable devices (FPDs) (e.g., field programmable gate arrays (FPGAs), programmable logic devices (PLDs), complex PLDs (CPLDs), high-volume PLDs (HCPLDs), structured ASICs, or programmable SoCs), digital signal processors (DSPs), etc., configured to provide a described function. In some embodiments, a circuitry may execute one or more software or firmware programs to provide at least some of the described functionality. The term “circuitry” may also refer to a combination of one or more hardware elements (or a combination of circuits used in an electrical or electronic system) with program code used to perform the functions of the program code. In these embodiments, the combination of hardware elements and program code may be referred to as a particular type of circuit.

[0083] The term "processor circuitry" or "processor," as used herein, therefore, refers to, is a part of, or includes circuitry capable of sequentially and automatically performing a series of arithmetic or logical operations, or recording, storing, and / or transferring digital data. The term "processor circuitry" or "processor" may refer to one or more application processors, one or more baseband processors, physical central processing units (CPUs), single or multi-core processors, and / or any other device capable of executing or otherwise operating computer-executable instructions, such as program code, software modules, and / or functional processes.

[0084] Multi-TRP operation was introduced in 5G NR Rel-16. In 5G NR Rel-16, multi-TRP operation was used for the physical downlink shared channel (PDSCH). Depending on different backhaul assumptions (ideal or non-ideal backhaul), multi-TRP operation includes single-DCI operation and multi-DCI operation. FIG. 3A illustrates single-downlink control information (DCI) TRP operation according to some embodiments. FIG. 3B illustrates multi-DCI TRP operation according to some embodiments. Note that for convenience, only some elements are shown, and other elements may be present. As shown in FIGS. 3A and 3B, the system 300 includes multiple TRPs (TRP#A 302a, TRP#B 302b) communicating with the UE 304. The TRP#A 302a and the TRP#B 302b may each transmit multiple PDSCHs using different beams. One of the multiple PDSCHs from each of TRP#A 302a and TRP#B 302b may be received by the UE 304.

[0085] Single-DCI operation, such as that shown in FIG. 3A, can be employed with an ideal backhaul assumption. In single-DCI operation, a single physical downlink control channel (PDCCH) transmission may schedule PDSCH transmissions from multiple TRPs. This is shown in FIG. 3A as PDSCH#1 from TRP#A 302a scheduling according to the PDCCH from TRP#A 302a. Multi-DCI operation, such as that shown in FIG. 3B, can be employed with a non-ideal backhaul assumption. In multi-DCI operation, each TRP may use a single PDCCH to schedule a corresponding PDSCH transmission. This is shown in FIG. 3B as PDSCH#1 from TRP#A 302a scheduling PDCCH#1 from TRP#A 302a and PDSCH#2 from TRP#B 302b scheduling PDCCH#2 from TRP#B 302b.

[0086] In multi-DCI multi-TRP operation, multiple control resource set (CORESET) pools may exist. Each CORESET is a set of physical resources and parameters used to carry PDCCH / DCI. One CORESET may be configured with the parameter CORESETPoolIndex, which can distinguish TRPs. For example, a value of 0 for CORESETPoolIndex may correspond to TRP #A, and a value of 1 may correspond to TRP #B.

[0087] In single DCI multi-TRP operation, a codepoint in the transmission configuration indication (TCI) field in the DCI can be associated with one or two TCI states. Figure 4 shows a MAC-CE according to some embodiments. The MAC-CE can be used to configure a TCI codepoint with multiple TCI states. The fields of the MAC-CE are defined as follows:

[0088] Serving Cell ID: This field indicates the identity of the serving cell to which the MAC CE applies. The length of the field is 5 bits.

[0089] Bandwidth Fraction Indicator (BWP) ID: This field indicates the DL BWP to which the MAC CE applies as a codepoint in the DCI Bandwidth Fraction Indicator field as specified in TS38.212. The length of the BWP ID field is 2 bits.

[0090] C i :This field is the TCI state ID i,2 If this field is set to "1", it indicates whether an octet containing the TCI State ID is present. i,2 If this field is set to "0", the TCI State ID is i,2 There is no octet containing

[0091] TCI State ID i,j: This field indicates the TCI state identified by TCI-StateId as specified in TS38.331, where i is the index of the codepoint in the DCI transmission configuration indication field as specified in TS38.212, and the TCI state ID i,j indicates the j-th TCI state indicated for the i-th code point in the DCI transmission configuration indication field. The TCI code point to which the TCI state is mapped is the TCI state ID i,j It is determined by its ordinal position among all TCI codepoints that have a set of fields, i.e., TCI Status ID 0,1 and TCI State ID 0,2 The first TCI codepoint with 1,1 and TCI State ID 1,2 The second TCI codepoint with a TCI State ID is mapped to codepoint value 1, and so on. i,2 is C i Optionally based on the indication in the field. The maximum number of activated TCI codepoints is 8, and the maximum number of TCI states mapped to a TCI codepoint is 2.

[0092] R: Reserved bits set to "0"

[0093] In NR Rel-15, a MAC-CE is defined to update the spatial relationship of semi-persistent SRS. In Rel-16, another MAC-CE is defined to update the spatial relationship of aperiodic SRS. Figure 5 shows a MAC-CE for updating the spatial relationship of semi-persistent SRS according to some embodiments. The MAC-CE in Figure 5 is for semi-persistent (SP) SRS activation / deactivation. The fields of the MAC-CE in Figure 5 are defined as follows:

[0094] A / D: This field indicates whether to activate or deactivate the indicated SP SRS resource set. The field is set to 1 to indicate activation, otherwise it indicates deactivation.

[0095] Cell ID of SRS resource set: This field indicates the identity of the serving cell, which contains the activated / deactivated SP SRS resource set. If the C field is set to 0, this field also contains the resource ID i Indicates the identity of the serving cell that contains all resources indicated by the field. The length of the field is 5 bits.

[0096] BWP ID of SRS resource set: This field indicates the UL BWP as a codepoint of the DCI Bandwidth Portion Indicator field as specified in TS38.212, which contains the activated / deactivated SP SRS resource set. If the C field is set to 0, this field also contains the resource ID i This field indicates the identity of the BWP that contains all resources indicated by the field. The field is 2 bits in length.

[0097] C: This field indicates whether the octets containing the Resource Serving Cell ID and Resource BWP ID fields are present. If this field is set to 1, the octets containing the Resource Serving Cell ID and Resource BWP ID fields are present; otherwise, they are not present.

[0098] Supplementary Uplink (SUL): This field indicates whether the MAC CE applies to a normal uplink (NUL) carrier or to an SUL carrier configuration. This field is set to 1 to indicate that it applies to an SUL carrier configuration, and is set to 0 to indicate that it applies to a NUL carrier configuration.

[0099] SP SRS Resource Set ID: This field indicates the SP SRS Resource Set ID identified by SRS-ResourceSetId as specified in TS38.331, which is to be activated or deactivated. The length of the field is 4 bits.

[0100] F i : This field indicates the type of resource used as the spatial relationship of the SRS resource in the SP SRS resource set indicated using the SP SRS Resource Set ID field. F0 refers to the first SRS resource in the resource set, F1 refers to the second SRS resource, and so on. The field is set to 1 to indicate that a non-zero power (NZP) channel status information (CSI)-RS resource index is used, or 0 to indicate that either a synchronization signal block (SSB) index or an SRS resource index is used. The length of the field is 1 bit. This field is only present if MAC CE is used for activation, i.e., the A / D field is set to 1.

[0101] Resource ID i : This field contains the identifier of the resource used to derive the spatial relationship for SRS resource i. Resource ID 0 refers to the first SRS resource in the resource set, resource ID 1 refers to the second SRS resource, and so on. F i If F is set to 0 and the first bit of this field is set to 1, the remainder of this field contains the SSB-Index as specified in TS38.331. iis set to 0 and the first bit of this field is set to 0, the remainder of this field contains the SRS-ResourceId as specified in TS38.331. The length of the field is 7 bits. This field is only present if MAC CE is used for activation, i.e., the A / D field is set to 1.

[0102] Resource Serving Cell ID i : This field indicates the identity of the serving cell whose resources are used to derive the spatial relationship in which SRS resource i is located. The length of the field is 5 bits.

[0103] Resource BWP ID i : This field indicates the UL BWP as the codepoint of the DCI Bandwidth Fraction Indicator field as specified in TS38.212, which resource is used to derive the spatial relationship in which SRS resource i is located. The length of the field is 2 bits.

[0104] R: Reserved bits set to 0

[0105] 6 illustrates a MAC-CE for updating spatial relationships of aperiodic SRS according to some embodiments. The fields of the MAC-CE are defined as follows:

[0106] Cell ID of SRS resource set: This field indicates the identity of the serving cell, which contains the indicated access point (AP) SRS resource set. If the C field is set to 0, this field also contains the resource ID i Indicates the identity of the serving cell that contains all resources indicated by the field. The length of the field is 5 bits.

[0107] BWP ID of SRS Resource Set: This field indicates the UL BWP as a codepoint of the DCI Bandwidth Portion Indicator field as specified in TS38.212, which contains the indicated AP SRS resource set. If the C field is set to 0, this field also indicates the resource ID i This field indicates the identity of the BWP that contains all resources indicated by the field. The field is 2 bits in length.

[0108] C: This field indicates whether the octets containing the Resource Serving Cell ID and Resource BWP ID fields are present. If this field is set to 1, the octets containing the Resource Serving Cell ID and Resource BWP ID fields are present; otherwise, they are not present.

[0109] SUL: This field indicates whether the MAC CE applies to the NUL carrier or the SUL carrier configuration. This field is set to 1 to indicate that it applies to the SUL carrier configuration, and is set to 0 to indicate that it applies to the NUL carrier configuration.

[0110] AP SRS Resource Set ID: This field indicates the AP SRS Resource Set ID identified by SRS-ResourceSetId as specified in TS38.331. The length of the field is 4 bits.

[0111] F i: This field indicates the type of resource used as the spatial relationship of the SRS resource in the AP SRS resource set indicated using the AP SRS Resource Set ID field. F0 refers to the first SRS resource in the resource set, F1 refers to the second SRS resource, and so on. The field is set to 1 to indicate that the NZP CSI-RS resource index is being used, and it is set to 0 to indicate that either the SSB index or the SRS resource index is being used. The length of the field is 1 bit. This field is only present if MAC CE is used for activation, i.e., the A / D field is set to 1.

[0112] Resource ID i : This field contains the identifier of the resource used to derive the spatial relationship for SRS resource i. Resource ID 0 refers to the first SRS resource in the resource set, resource ID 1 refers to the second SRS resource, and so on. F i If F is set to 0 and the first bit of this field is set to 1, the remainder of this field contains the SSB-Index as specified in TS38.331. i If is set to 0 and the first bit of this field is set to 0, the remainder of this field contains the SRS-ResourceId as specified in TS38.331. The length of the field is 7 bits.

[0113] Resource Serving Cell ID i : This field indicates the identity of the serving cell in which the resource used to derive the spatial relationship of SRS resource i is located. The length of the field is 5 bits.

[0114] Resource BWP ID i: This field indicates the UL BWP as the codepoint of the DCI Bandwidth Fraction Indicator field as specified in TS38.212, where the resource used to derive the spatial relationship of SRS resource i is located. The length of the field is 2 bits.

[0115] R: Reserved bits set to 0

[0116] In NR Rel-16, another MAC-CE is defined to update the spatial relationship of the PUCCH, details of which are found in TS38.321.

[0117] In NR Rel-15, for PUSCH scheduling with DCI format0_0, a default spatial relationship may be applied. This default spatial relationship may be the spatial relationship of the PUCCH resource with the lowest resource ID on a component carrier (CC). If no PUCCH resource is configured on a CC or if a PUCCH resource is configured but without a spatial relationship, then the UE is not expected to be scheduled by DCI0_0.

[0118] In NR Rel-16, default beam operation is defined for SRS, PUCCH, and PUSCH scheduled by DCI0_0 to reduce overhead. If the default beam is enabled for SRS / PUCCH, then the SRS / PUCCH may be configured without spatial relationship information, and the MAC-CE that updates the spatial relationship of the SRS / PUCCH may not be transmitted, so that MAC-CE overhead is reduced. If the default beam is enabled for PUSCH, then the PUSCH may be scheduled by DCI format0_0 even if no PUCCH resource is configured on the CC or if a PUCCH resource is configured but without spatial relationship.

[0119] If the parameter enableDefaultBeamPlForSRS is set to "enabled", then the default spatial relationship / path loss reference signal for SRS operation is the TCI state / QCL assumption of the CORESET with the lowest ID if a CORESET is configured on the CC, or the activated TCI state with the lowest ID of the PDSCH if no CORESET is configured on the CC.

[0120] If the parameter enableDefaultBeamPlForPUCCH is set to "enabled", then the default spatial relationship / path loss reference signal for PUCCH is the TCI state / QCL assumption of the CORESET with the lowest ID if the CORESET is configured on the CC.

[0121] If the parameter enableDefaultBeamPlForPUSCH0_0 is set to "enabled", then the default spatial relationship / path loss reference signal of the PUSCH scheduled by DCI0_0 is the TCI state / QCL assumption of the CORESET with the lowest ID if no PUCCH resources are configured on the active BWP in the CC, or if PUCCH resources are configured but without spatial relationship, then the default spatial relationship / path loss reference signal may follow the default spatial relationship / path loss reference signal of those PUCCH resources.

[0122] However, the existing default spatial relationship design for SRS / PUCCH / PUSCH applies to single TRP. To support multi-TRP operation, the default spatial relationship design is further enhanced as described below for both single DCI and multi-DCI transmissions.

[0123] Default PUCCH spatial relationship for multiple TRPs with single DCI

[0124] 1. A single spatial relationship associated with one PUCCH resource

[0125] In single-DCI multi-TRP operation, one PUCCH resource may be associated with only one spatial relationship. To reduce overhead, a default beam / spatial relationship may be applied to PUCCH transmission. An existing parameter, for example, enableDefaultBeamPlForPUCCH, can be reused to indicate whether the default spatial relationship / beam for PUCCH transmission is enabled. If this parameter is enabled, then the spatial relationship and path loss reference signal are not configured for the PUCCH transmission. This avoids additional MAC-CE transmissions to update the spatial relationship for PUCCH transmission and reduces overhead.

[0126] In single DCI multi-TRP operation, a PUCCH can be associated with one TRP. The association can be defined at the PUCCH resource set level / PUCCH resource group level / PUCCH resource level by a new parameter associatedTRP-PUCCH. Alternatively, the TRP associated with a PUCCH can be configured / updated via MAC-CE. If a PUCCH resource is indicated by a DCI, the parameter associatedTRP-PUCCH can also be included in the DCI as a new field. In another example, the TRP associated with a PUCCH can be implicitly represented by a PUCCH resource group ID or a PUCCH resource set ID.

[0127] The association between PUCCH and TRP in this section (Section 1) is not limited to the default beam operation for PUCCH - the association can also be applied in other scenarios for PUCCH transmission. The association can be defined at the PUCCH resource set level / PUCCH resource group level / PUCCH resource level or in the PUCCH spatial relationship information.

[0128] The default spatial relationship / default path loss reference signal for the PUCCH may be determined according to the associated TRP. The association between the PUCCH and the TRP, i.e., associatedTRP-PUCCH, may be linked to the TRP, for example, via a TRP ID. The TRP ID may be, for example, a logical or physical cell ID. Alternatively, the association between the PUCCH and the TRP may be linked to one TRP, for example, via a CORESET, a CORESET pool, a TCI state, etc., as described in the following sections.

[0129] [1.1 Spatial relationships determined based on explicit associations between CORESET and TRP]

[0130] In the case of single DCI multi-TRP operation, a CORESET may also be associated with one TRP. A CORESET pool may also be defined for single DCI multi-TRP operation. The association between a CORESET and a TRP may be defined by an RRC parameter, for example, singleDCI-CORESETPoolIndex. If singleDCI-CORESETPoolIndex is set to 0, the CORESET is transmitted from TRP #A, and if singleDCI-CORESETPoolIndex is set to 1, the CORESET is transmitted from TRP #B.

[0131] For PUCCH transmission, the PUCCH can be associated with different CORESET pools via associatedTRP-PUCCH: if associatedTRP-PUCCH is set to 0, then the PUCCH is associated with CORESET pool index #0, i.e., TRP #A, and if set to 1, then the PUCCH is associated with TRP #B.

[0132] In this case, if enableDefaultBeamPlForPUCCH is enabled and neither spatial relation nor path loss reference signal is configured for PUCCH, the default spatial relation / path loss reference signal for PUCCH applies and may be determined as follows:

[0133] Alt1: The default PUCCH spatial relationship / path loss reference signal may follow the TCI / QCL assumptions of one CORESET. The default spatial relationship / path loss reference signal of the PUCCH may follow the TCI state / QCL assumptions of the lowest-indexed CORESET among those CORESETs whose configured single DCI-CORESETPoolIndex is the same as the CORESET pool associated with the PUCCH, and in the latest slot, one or more CORESETs whose configured single DCI-CORESETPoolIndex is the same as the CORESET pool associated with the PUCCH are monitored by the UE. The "latest slot" is prior to the PUCCH transmission. The associated CORESET pool with the PUCCH is indicated by associatedTRP-PUCCH, or the associated CORESET pool is the same as the scheduling CORESET if the PUCCH is indicated by DCI.

[0134] In the case of PUCCH indicated by DCI, the default spatial relationship / path loss reference signal may alternatively follow the TCI state / QCL assumption of the scheduling CORESET.

[0135] This association may also apply in the case of dynamic switching between single-TRP and multi-TRP operation.

[0136] 7 illustrates a default spatial relationship determination for PUCCH in accordance with some embodiments, where CORESET in a single DCI is associated with a TRP.

[0137] [1.2 Spatial relationships determined based on explicit associations between CORESETs (multi-TCI states) and TRPs]

[0138] In the case of single-DCI multi-TRP operation, if a CORESET is configured with multiple activated TCI states, then the TCI state of the CORESET is associated with one TRP. A TCI state may be associated with one TRP via a TRP ID, which may be, for example, a logical or physical cell ID as described above. Alternatively, a CORESET pool may be defined, one CORESET pool may represent one TRP, and an association may be defined between the TCI state and the CORESET pool. In this case, the parameter associatedTRP-TCI may be introduced in TCI-State. Alternatively, the association between the TCI state and the TRP may be configured / updated via the MAC-CE. In another alternative, the order of the TCI states of one CORESET may implicitly indicate the association between the TCI state and the TRP. For example, if one CORESET is configured with two active TCI states, then the first TCI state is associated with the first TRP, and the second TCI state is associated with the second TRP.

[0139] CORESET may be configured with a CORESET pool index or without a CORESET pool index. In this case, if enableDefaultBeamPlForPUCCH is enabled and neither spatial relation nor path loss reference signal is configured for PUCCH, the default spatial relation / path loss reference signal for PUCCH may be applied and determined as follows:

[0140] Alt1: The default PUCCH spatial relationship / path loss reference signal may follow one TCI / QCL assumption for one CORESET. The default spatial relationship / path loss reference signal for the PUCCH may follow the TCI state / QCL assumption associated with the same TRP as the PUCCH for the CORESET with the lowest index among those CORESETs with at least one activated TCI state, and the TCI state is associated with the same TRP as the PUCCH in the most recent slot in which one or more such CORESETs are monitored by the UE (either explicitly via the TCI state associatedTRP-TCI or implicitly via the ordering of the TCI states). The "most recent slot" is prior to the PUCCH transmission.

[0141] The associated TRP with the PUCCH may be indicated by associatedTRP-PUCCH. Alternatively, the associated CORESET pool may be the same as the scheduling CORESET if the PUCCH is indicated by DCI. For PUCCHs indicated by DCI, the default spatial relationship / path loss reference signal may alternatively follow the TCI state / QCL assumption of the scheduling CORESET associated with the same TRP as the PUCCH.

[0142] Alt2: The default PUCCH spatial relationship / path loss reference signal may follow one TCI state. The default spatial relationship / path loss reference signal of the PUCCH may follow the TCI state / QCL hypothesis with the lowest TCI state ID among those TCI states of the CORESET, where the TCI state is associated with the same TRP as the PUCCH (either explicitly via the TCI state associatedTRP-TCI or implicitly via the order of the TCI states) in the latest slot in which at least one CORESET with at least one TCI state associated with the same TRP as the PUCCH is monitored by the UE. The "latest slot" is prior to the PUCCH transmission.

[0143] The associated TRP with the PUCCH may be indicated by associatedTRP-PUCCH. Alternatively, the associated CORESET pool may be the same as the scheduling CORESET if the PUCCH is indicated by DCI. For PUCCHs indicated by DCI, the default spatial relationship / path loss reference signal may alternatively follow the TCI state / QCL assumption of the scheduling CORESET associated with the same TRP as the PUCCH.

[0144] This may also apply in the case of dynamic switching between single-TRP and multi-TRP operation.

[0145] FIG. 8 illustrates PUCCH default spatial relationships based on CORESET TCI state and TRP according to some embodiments. 9 illustrates another PUCCH default spatial relationship based on CORESET TCI state and TRP in accordance with some embodiments. In particular, FIG. 8 illustrates an example of Alt1 operation, and FIG. 9 illustrates an example of Alt2 operation.

[0146] [1.3 Spatial relationships determined based on implicit associations between TCI states and TRPs]

[0147] In single DCI multi-TRP operation, for the TCI states of the PDSCH, at least one TCI codepoint contains multiple TCI states. Some constraints are introduced for the TCI states of the PDSCH. The order of the TCI states may implicitly indicate the association between the TRP and the TCI state. In an example, for those TCI codepoints containing multiple TCI states, the first TCI state may be associated with the same TRP, and the second TCI state may be associated with another TRP. For example, the TCI state ID i,j In this case, for all code points that contain multiple TCI states, the TCI state ID i,1 can be associated with TRP #A, and TCI state ID i,2 may be associated with TRP #B. 10 illustrates an example of an association between a TRP and a TCI state according to some embodiments. In particular, FIG. 10 illustrates an example of an implicit association between a TCI state and a TRP.

[0148] For PUCCH, the association between TRP and PUCCH may be defined as follows: if the parameter associatedTRP-PUCCH is set to 0, the PUCCH is associated with the first TCI state, i.e., TRP #A, in those TCI codepoints that contain multiple TCI states, and if set to 1, the PUCCH is associated with the second TCI state, i.e., TRP #B.

[0149] In this case, if enableDefaultBeamPlForPUCCH is enabled and neither spatial relation nor path loss reference signal is configured for PUCCH, the default spatial relation / path loss reference signal for PUCCH may be applied and determined as follows:

[0150] Alt1: The default PUCCH spatial relationship / path loss reference signal may dynamically follow the indicated TCI state. The default spatial relationship / path loss reference signal of the PUCCH may follow one of the indicated TCI states / QCL assumptions for PDSCH reception in the latest slot in which PDSCH reception with multiple TCI states is performed. Whether to follow the first state or the second TCI state may be further indicated by the parameter associatedTRP-PUCCH in the RRC or DCI. In the case of a PUCCH indicated by a DCI, the default spatial relationship / path loss reference signal may alternatively follow the TCI state / QCL assumption of the scheduling CORESET.

[0151] Alt2: The default PUCCH spatial relationship / path loss reference signal may semi-statically follow one TCI state indicated by one TCI state codepoint. The default spatial relationship / path loss reference signal of the PUCCH may follow one of the TCI states corresponding to the lowest codepoint among the TCI states activated for the PDSCH. Whether to follow the first state or the second TCI state is further indicated by the parameter associatedTRP-PUCCH in the RRC or DCI. For the PUCCH indicated by the DCI, the default spatial relationship / path loss reference signal may alternatively follow the TCI state / QCL assumption of the scheduling CORESET.

[0152] FIG. 11 illustrates an example of PUCCH default spatial relationships with implicit associations according to some embodiments. Figure 12 illustrates another example of a PUCCH default spatial relationship with implicit association according to some embodiments. In particular, Figure 11 illustrates the above Alt1 example, and Figure 12 illustrates the above Alt2 example of an implicit association between TCI and TRP.

[0153] [1.4 Spatial relationships determined based on explicit associations between TCI states and TRPs]

[0154] A downlink TCI state may be associated with one TRP. For example, a TCI state may be associated with one TRP, e.g., via a TRP ID; alternatively, a CORESET pool may be defined as one CORESET pool representing one TRP, and the association may be defined between the TCI state and the CORESET pool. A parameter associatedTRP-TCI may be introduced in TCI-State. Alternatively, the association between the TCI state and the TRP may be configured / updated via the MAC-CE. In another example, the order of the TCI states may implicitly indicate the association between the TRP and the TCI state when one codepoint indicates multiple TCI states.

[0155] Figure 13 illustrates an example of a PUCCH default spatial relationship with explicit association according to some embodiments. Figure 13 illustrates an example of an explicit association between a TCI state and a TRP. In this case, if enableDefaultBeamPlForPUCCH is enabled and neither a spatial relationship nor a path loss reference signal is configured for PUCCH, the default spatial relationship / path loss reference signal for PUCCH is applied and is determined as follows:

[0156] Alt1: Default PUCCH spatial relationship / path loss reference signals may dynamically follow the indicated TCI state. Default spatial relationship / path loss reference signals for PUCCH may follow the indicated TCI state / QCL assumption for PDSCH reception in the latest slot in which PDSCH reception is performed with one TCI state whose associatedTRP-TCI has the same value as associatedTRP-PUCCH. For PUCCH indicated by DCI, default spatial relationship / path loss reference signals may alternatively follow the TCI state / QCL assumption of the scheduling CORESET.

[0157] Alt2: The default PUCCH spatial relationship / path loss reference signal may semi-statically follow one TCI state indicated by one TCI state codepoint. The default spatial relationship / path loss reference signal for the PUCCH may follow the TCI state with the lowest TCI state ID among those TCI states whose associatedTRP-TCI has the same value as the associatedTRP-PUCCH. For the PUCCH indicated by the DCI, the default spatial relationship / path loss reference signal may alternatively follow the TCI state / QCL assumption of the scheduling CORESET. In another example, the default spatial relationship / path loss reference signal for the PUCCH may follow one TCI state indicated by the lowest TCI state codepoint that includes multiple TCI states. The TCI state may be associated with the same TRP as the PUCCH.

[0158] This may also apply in the case of dynamic switching between single-TRP and multi-TRP operation.

[0159] FIG. 14 illustrates another example of a PUCCH default spatial relationship with explicit association according to some embodiments. Figure 15 illustrates another example of a PUCCH default spatial relationship with an explicit association according to some embodiments. In particular, Figure 14 illustrates the above Alt1 example with an explicit association between a TCI and a TRP, and Figure 15 illustrates the above Alt2 example with an explicit association between a TCI and a TRP.

[0160] 2. Multiple spatial relationships associated with one PUCCH resource

[0161] In single-DCI multi-TRP operation, when one PUCCH resource is configured with multiple spatial relationships, multiple default beams / spatial relationships may be applied to PUCCH transmission to reduce overhead. A new RRC parameter, such as enableMultipleDefaultBeam-PUCCH, may be introduced to indicate whether multiple default spatial relationships / beams are enabled for PUCCH transmission. If this parameter is enabled, then spatial relationships and path loss reference signals are not configured for PUCCH. Alternatively, spatial relationships and path loss reference signals may be configured but instead ignored. In this way, the gNB may avoid additional MAC-CE transmissions to update the spatial relationships of PUCCH transmissions, and overhead may be reduced. The parameter enableMultipleDefaultBeam-PUCCH may be included in UplinkConfig, PUCCH-Config, or PUCCH-Resource. If the parameter enableMultipleDefaultBeam-PUCCH is included in UplinkConfig or PUCCH-Config, all PUCCH resources are enabled with multiple default spatial relationships. If the parameter enableMultipleDefaultBeam-PUCCH is included in PUCCH-Resource, this PUCCH resource is enabled with multiple default spatial relationships. The parameter enableMultipleDefaultBeam-PUCCH may be defined at the PUCCH resource set level / PUCCH resource group level.

[0162] When multiple spatial relationships are associated with one PUCCH resource, the spatial relationships may be associated with different TRPs. In an example, the order of the (default) spatial relationships may implicitly indicate the associated TRPs. For example, a first (default) spatial relationship is associated with a first TRP, and a second (default) spatial relationship is associated with a second TRP. In another example, a PUCCH may be explicitly associated with multiple TRPs via a new RRC parameter.

[0163] The association between PUCCH and TRP in this section (Section 2) is not limited to the default beam operation for PUCCH, and it may be applied to other scenarios for PUCCH transmission. The association may be defined at the PUCCH resource set level / PUCCH resource group level / PUCCH resource level, or in the PUCCH spatial relationship information.

[0164] The default spatial relationship / default path loss reference signal for the PUCCH may be determined as described in the following sections.

[0165] [2.1 Spatial relationship determined based on the association between CORESET and TRP]

[0166] In the case of single DCI multi-TRP operation, a CORESET may also be associated with one TRP. A CORESET pool may also be defined for single DCI multi-TRP operation. The association between a CORESET and a TRP may be defined by an RRC parameter, for example, singleDCI-CORESETPoolIndex. If singleDCI-CORESETPoolIndex is set to 0, the CORESET is transmitted from TRP #A, and if singleDCI-CORESETPoolIndex is set to 1, the CORESET is transmitted from TRP #B.

[0167] In this case, if enableMultipleDefaultBeam-PUCCH is enabled and neither spatial relation nor path loss reference signal is configured for PUCCH, the default spatial relation / path loss reference signal for PUCCH may be applied and determined as follows:

[0168] Alt 1: Multiple default PUCCH spatial relationship / path loss reference signals independently follow the TCI / QCL assumptions of one CORESET. A first default spatial relationship / path loss reference signal of the PUCCH may follow the TCI state / QCL assumptions of the lowest-indexed CORESET(s) associated with the first TRP in the most recent slot in which the UE monitors the one or more CORESET(s) associated with the first TRP. A second default spatial relationship / path loss reference signal of the PUCCH may follow the TCI state / QCL assumptions of the lowest-indexed CORESET(s) associated with the second TRP in the most recent slot in which the UE monitors the one or more CORESET(s) associated with the second TRP.

[0169] 16 illustrates another example of a PUCCH having multiple spatial relationships according to some embodiments. In particular, in FIG. 14, the PUCCH has multiple spatial relationships determined according to the association between CORESET and TRP.

[0170] 2.2 Spatial relationships determined based on the association between CORESET (multiple TCI states) and TRP

[0171] In the case of single-DCI multi-TRP operation, if a CORESET is configured with multiple activated TCI states, then the TCI state of the CORESET is associated with one TRP. A TCI state may be associated with one TRP, for example, via a TRP ID. Alternatively, a CORESET pool may be defined as one CORESET pool that may represent one TRP, and the association may be defined between the TCI state and the CORESET pool. A parameter associatedTRP-TCI may be introduced in TCI-State. Alternatively, the association between the TCI state and the TRP may be configured / updated via the MAC-CE. In another alternative, the order of the TCI states of one CORESET may implicitly indicate the association between the TCI state and the TRP. For example, if one CORESET is configured with two active TCI states, then the first TCI state is associated with the first TRP, and the second TCI state is associated with the second TRP.

[0172] CORESET may be configured with a CORESET pool index or may be configured without a CORESET pool index. In this case, if enableMultipleDefaultBeam-PUCCH is enabled and neither spatial relation nor path loss reference signal is configured for PUCCH, the default spatial relation / path loss reference signal for PUCCH may be applied and determined as follows:

[0173] Alt 1: Multiple default PUCCH spatial relationship / path loss reference signals independently follow one TCI / QCL assumption of one CORESET. A first default spatial relationship / path loss reference signal of the PUCCH may follow the TCI state / QCL assumption associated with a first TRP of the lowest-indexed CORESET having at least one TCI state associated with the first TRP in the most recent slot in which one or more such CORESETs are monitored by the UE. A second default spatial relationship / path loss reference signal of the PUCCH may follow the TCI state / QCL assumption associated with a second TRP of the lowest-indexed CORESET having at least one TCI state associated with the second TRP in the most recent slot in which one or more CORESETs associated with the second TRP are monitored by the UE.

[0174] Alt2: Multiple default PUCCH spatial relationship / path loss reference signals sequentially following the TCI / QCL assumptions of one CORESET. The PUCCH default spatial relationship / path loss reference signals may sequentially follow the TCI state / QCL assumptions of the CORESET with the lowest index among those CORESETs configured in multiple activation states associated with different TRPs in the latest slot in which one or more such CORESETs are monitored by the UE.

[0175] Alt3: Multiple default PUCCH spatial relationship / path loss reference signals that sequentially follow the TCI / QCL assumptions of the scheduling CORESET. The PUCCH default spatial relationship / path loss reference signals sequentially follow the TCI state / QCL assumptions of the scheduling CORESET when the scheduling CORESET is configured with multiple active TCI states.

[0176] Note: For Alt.2 / Alt.3, PUCCH can be configured with or without TRP association. CORESET TCI state can be configured with or without TRP association. Association includes explicit or implicit association.

[0177] FIG. 17 illustrates another example of a PUCCH with multiple spatial relationships in accordance with some embodiments. Figure 18 illustrates another example of a PUCCH with multiple spatial relationships in accordance with some embodiments. In particular, Figure 17 illustrates the above Alt1 example with an association between a CORESET TCI and a TRP, and Figure 18 illustrates the above Alt2 example of an association between a CORESET TCI and a TRP.

[0178] [2.3 Spatial relationships determined based on associations between TCI states and TRPs]

[0179] In an embodiment, in the case of single DCI multi-TRP operation, if at least one TCI codepoint indicates multiple TCI states, the default spatial relationship / path loss reference signal for the PUCCH may be determined as follows:

[0180] Alt1: Multiple default PUCCH spatial relationship / path loss reference signals dynamically follow the indicated TCI states of the PDSCH. The default spatial relationship / path loss reference signals of the PUCCH sequentially follow the indicated TCI states / QCL assumptions for PDSCH reception in the latest slot in which the PDSCH is received in multiple TCI states indicated by one TCI codepoint.

[0181] Alt2: Multiple default PUCCH spatial relationship / path loss reference signals semi-statically follow multiple TCI states indicated by one TCI state codepoint. The default spatial relationship / path loss reference signal for the PUCCH sequentially follows the TCI state corresponding to the lowest TCI codepoint among the TCI codepoints that include multiple TCI states activated for the PDSCH.

[0182] Alt3: Multiple default PUCCH spatial relationship / path loss reference signals are semi-statically and independently derived. If the TCI states are configured in explicit association with the TRP, then the first default spatial relationship / path loss reference signal of the PUCCH may follow the TCI state with the lowest TCI state ID among those TCI states associated with the first TRP, and the second default spatial relationship / path loss reference signal of the PUCCH may follow the TCI state with the lowest TCI state ID among those TCI states associated with the second TRP. In this embodiment, the PUCCH may be configured with or without association with the TRP. The TCI states may be configured with or without association with the TRP. The association includes explicit or implicit association.

[0183] FIG. 19 illustrates another example of a PUCCH with multiple spatial relationships in accordance with some embodiments. Figure 20 illustrates another example of a PUCCH with multiple spatial relationships in accordance with some embodiments. In particular, Figure 19 illustrates the above Alt1 example with multiple spatial relationships determined according to an association between TCI and TRP, and Figure 20 illustrates the above Alt2 example with multiple spatial relationships determined according to an association between TCI and TRP.

[0184] The methods in Section 1 and Section 2 may be used jointly. For example, if in a system some PUCCH resources are associated with only one spatial relationship and some PUCCH resources are associated with multiple spatial relationships, then the method from Section 1 may be used to derive default spatial relationships for those PUCCH resources with one spatial relationship, and the method from Section 2 may be used to derive default spatial relationships for those PUCCH resources with multiple spatial relationships.

[0185] [Default SRS spatial relationship for multi-TRP with single DCI]

[0186] [1. SRS configuration with multiple spatial relationships]

[0187] For SRS transmission in multiple TRPs with a single DCI, one SRS resource may consist of multiple spatial relations / Tx beams. The SRS resource may be transmitted with repetitions, and different spatial relations may apply to the repetitions, for example, targeting different TRPs. FIG. 21(a) illustrates an example of an SRS with multiple spatial relationships with sequential mapping according to some embodiments. Figure 21(b) shows an example of an SRS with multiple spatial relationships with periodic mapping according to some embodiments. That is, Figure 21(a) shows a sequential mapping between SRS spatial relationships and SRS repetitions, and Figure 21(b) shows a periodic mapping between SRS spatial relationships and SRS repetitions. A TRP may not trigger an SRS transmission; one purpose of the SRS is to derive the spatial relationship for PUSCH transmissions.

[0188] All or some of the SRS resources in one SRS resource set may be configured with multiple spatial relationships. In an SRS resource set, multiple path loss reference signals may also be configured targeting different TRPs. An example of an RRC configuration for SRS resources with multiple spatial relationships may be as follows: SRS-Resource ::= SEQUENCE { ... ... resourceType CHOICE { aperiodic SEQUENCE { ... }, semi-persistent SEQUENCE { periodicityAndOffset-sp SRS-PeriodicityAndOffset, ... }, periodic SEQUENCE { periodicityAndOffset-p SRS-PeriodicityAndOffset, ... } }, sequenceId INTEGER (0..1023), spatialRelationInfo SRS-SpatialRelationInfo OPTIONAL, -- Need R spatialRelationInfo-List SEQUENCE (SIZE(1..maxNrofSRS-spatialRelationInfo-1)) OF SRS-SpatialRelationInfo OPTIONAL ..., [[ resourceMapping-r16 SEQUENCE { startPosition-r16 INTEGER (0..13), nrofSymbols-r16 ENUMERATED {n1, n2, n4}, repetitionFactor-r16 ENUMERATED {n1, n2, n4} } OPTIONAL -- Need R ]] }

[0189] As shown, a parameter additionalSpatialRelationInfo may be introduced into the RRC configuration to optionally indicate a second spatial relationship of the SRS.

[0190] 22 illustrates an example of a semi-persistent SRS activation / deactivation MAC CE with multiple spatial relationships according to some embodiments. The fields of the MAC-CE may be defined as follows:

[0191] M: This field indicates whether multiple spatial relationships are configured for one SRS resource. If this field is set to '1', then multiple spatial relationships are configured for SRS resource i, e.g., F i,0 and F i,1 If this field is set to '0', then only one spatial relationship is configured for the SRS resource i, e.g., F i,1 is constructed for non-existent octets.

[0192] F i,j : This field indicates the type of resource used as the spatial relation j of SRS resource i in the SP SRS resource set indicated using the SP SRS Resource Set ID field. F 0,0 refers to the first spatial relationship of the first SRS resource in the resource set, and F 0,1 refers to the second spatial relationship of the first SRS resource in the resource set, and F 1,0 refers to the first spatial relationship of the second SRS resource in the resource set, and F 1,1 refers to the second spatial relationship of the second SRS resource in the resource set, and so on. The field is set to 1 to indicate that the NZP CSI-RS resource index is used, and to 0 to indicate that either the SSB index or the SRS resource index is used. The length of the field is 1 bit. This field is only present if MAC CE is used for activation, e.g., the A / D field is set to 1.

[0193] Resource ID i,j : This field contains the identifier of the resource used to derive the spatial relation j for SRS resource i. Resource ID 0,0 refers to the first spatial relationship of the first SRS resource in the resource set, and the resource ID 0,1 refers to the second spatial relationship of the first SRS resource in the resource set, and the resource ID 1,0refers to the first spatial relationship of the second SRS resource in the resource set, and the resource ID 1,1 refers to the second spatial relationship of the second SRS resource in the resource set, and so on. i,j If F is set to 0 and the first bit of this field is set to 1, the remainder of this field contains the SSB-Index as specified in TS38.331. i,j is set to 0 and the first bit of this field is set to 0, the remainder of this field contains the SRS-ResourceId as specified in TS38.331. The length of the field is 7 bits. This field is only present if MAC CE was used for activation, e.g., the A / D field is set to 1.

[0194] Resource Serving Cell ID i,j : This field indicates the identity of the serving cell in which the resource used to derive the spatial relationship j of SRS resource i is located. The length of the field is 5 bits.

[0195] Resource BWP ID i,j : This field indicates the UL BWP as the codepoint of the DCI Bandwidth Fraction Indicator field as specified in TS38.212, where the resource used to derive the spatial relationship j of SRS resource i is located. The length of the field is 2 bits.

[0196] The other fields are the same as those previously described.

[0197] Figure 23 shows an example of an aperiodic SRS spatial relationship indication MAC CE according to some embodiments. The field definitions are the same as above, except for the AP SRS resource set ID field, which indicates the aperiodic SRS resource set. In the DCI, the code point of the SRI field may indicate multiple spatial relationships. For example, if the SRI indicates SRS resource #2, then multiple spatial relationships of SRS resource #2 are indicated.

[0198] [2. A single spatial relationship associated with one SRS resource]

[0199] In single-DCI multi-TRP operation, one SRS resource is associated with only one spatial relationship. To reduce overhead, a default beam / spatial relationship may be applied to SRS transmission. An existing parameter, for example, enableDefaultBeamPlForSRS, can be reused to indicate whether the default spatial relationship / beam for SRS transmission is enabled. If this parameter is enabled, then the spatial relationship and path loss reference signal are not configured for the SRS. In this case, further MAC-CE transmissions to update the spatial relationship of the SRS transmission may be avoided, and overhead may be reduced.

[0200] In single DCI multi-TRP, an SRS is associated with one TRP. The association can be defined at the SRS resource set level / SRS resource level by a new parameter associatedTRP-SRS. Alternatively, the TRP associated with an SRS can be configured / updated via the MAC-CE. If the SRS resource is triggered by a DCI, the parameter associatedTRP-SRS can also be included in the DCI as a new field. In another example, the TRP associated with an SRS can be implicitly represented by the SRS resource set ID.

[0201] The association between the SRS and the TRP in this section (Section 2) is not limited to the default beam operation for the SRS. It may also be applied in other scenarios of SRS transmission, such as codebook / non-codebook based transmission. The association may be defined at the SRS resource set level / SRS resource level or in the SRS spatial relationship information.

[0202] The default spatial relationship / default path loss reference signal of an SRS may be determined according to the associated TRP. The association between an SRS and a TRP, e.g., associatedTRP-SRS, may be linked to the TRP, e.g., via a TRP ID (the TRP ID may be a logical or physical cell ID). Alternatively, the association between an SRS and a TRP may be linked to one TRP, e.g., via a CORESET, a CORESET pool, a TCI state, etc., as described in the following sections. In some cases, default beam operation may not be applicable to SRS transmission for beam management. In other cases, a TRP may not trigger an SRS transmission, and as described above, one purpose of the SRS is to derive the spatial relationship of a PUSCH transmission. In the absence of an SRS transmission, then, the default SRS spatial relationship is derived assuming that the SRS is transmitted in the first slot of a PUSCH transmission.

[0203] [2.1 Spatial relationships determined based on explicit associations between CORESET and TRP]

[0204] In the case of single DCI multi-TRP operation, a CORESET may also be associated with one TRP. A CORESET pool may also be defined for single DCI multi-TRP. The association between a CORESET and a TRP may be defined by an RRC parameter, for example, singleDCI-CORESETPoolIndex. If singleDCI-CORESETPoolIndex is set to 0, the CORESET is transmitted from TRP #A, and if singleDCI-CORESETPoolIndex is set to 1, the CORESET is transmitted from TRP #B.

[0205] In case of SRS transmission, the SRS is associated with a different CORESET pool via associatedTRP-SRS: if associatedTRP-SRS is set to 0, then the SRS is associated with CORESET pool index #0, e.g., TRP #A, and if associatedTRP-SRS is set to 1, then the SRS is associated with TRP #B.

[0206] In this case, if enableDefaultBeamPlForSRS is enabled and neither spatial relation nor path loss reference signal is configured for SRS transmission, the default spatial relation / path loss reference signal for SRS may be applied and determined as follows:

[0207] Alt1: Default SRS spatial relationship / path loss reference signals may follow the TCI / QCL assumptions of one CORESET: The default spatial relationship / path loss reference signals of the SRS may follow the TCI state / QCL assumptions of the CORESET with the lowest index among one or more CORESETs whose configured singleDCI-CORESETPoolIndex is the same as the CORESET pool associated with the SRS in the latest slot in which the UE monitors one or more CORESETs whose configured singleDCI-CORESETPoolIndex is the same as the CORESET pool associated with the SRS. The "latest slot" is prior to the SRS transmission.

[0208] The associated CORESET pool with the SRS is indicated by associatedTRP-SRS. Alternatively, the associated CORESET pool is the same as the scheduling CORESET if the SRS is triggered by a DCI.

[0209] In the case of SRS triggered by DCI, the default spatial relationship / path loss reference signal may alternatively follow the TCI state / QCL assumptions of the scheduling CORESET.

[0210] This may also apply in the case of dynamic switching between single-TRP and multi-TRP operation. 24 illustrates an example of an SRS default spatial relationship according to CORESET in accordance with some embodiments. In particular, FIG. 24 illustrates an example of an SRS default spatial relationship determination when CORESET in a single DCI is associated with a TRP.

[0211] [2.2 Spatial relationships determined based on explicit associations between CORESETs (multi-TCI states) and TRPs]

[0212] In the case of single-DCI multi-TRP operation, if a CORESET is configured with multiple activated TCI states, then the TCI state of the CORESET is associated with one TRP. A TCI state may be associated with one TRP, for example, via a TRP ID (which may be a logical or physical cell ID). Alternatively, a CORESET pool may be defined, where one CORESET pool represents one TRP, and an association may be defined between the TCI state and the CORESET pool. The parameter associatedTRP-TCI is introduced in TCI-State. Alternatively, the association between the TCI state and the TRP may be configured / updated via the MAC-CE. In another alternative, the order of the TCI states of one CORESET may implicitly indicate the association between the TCI state and the TRP. For example, if one CORESET is configured with two active TCI states, then the first TCI state is associated with the first TRP, and the second TCI state is associated with the second TRP.

[0213] A CORESET may be configured with or without a CORESET pool index.

[0214] In this case, if enableDefaultBeamPlForSRS is enabled and neither spatial relationship nor path loss reference signal is configured for an SRS, the default spatial relationship / path loss reference signal for the SRS may be applied and determined as follows:

[0215] Alt1: Default SRS spatial relationship / path loss reference signals may follow one TCI / QCL assumption for one CORESET: The default spatial relationship / path loss reference signal for an SRS may follow the TCI state / QCL assumption associated with the same TRP as the SRS in the lowest-indexed CORESET among those CORESETs with at least one activated TCI state, where the TCI state is associated with the same TRP as the SRS in the most recent slot in which one or more such CORESETs are monitored by the UE (explicitly via the TCI state associatedTRP-TCI or implicitly via the order of the TCI states). The "most recent slot" is prior to the SRS transmission. The associated TRP with the SRS may be indicated by associatedTRP-SRS. Alternatively, the associated CORESET pool may be the same as the scheduling CORESET if the SRS is triggered by a DCI. In the case of a DCI-triggered SRS, alternatively, the default spatial relationship / path loss reference signal may follow the TCI state / QCL assumptions associated with the same TRP as the SRS in the scheduling CORESET.

[0216] Alt2: Default SRS spatial relationship / path loss reference signals may follow one TCI state: The default spatial relationship / path loss reference signals of the SRS may follow the TCI state / QCL assumption with the lowest TCI state ID among those TCI states of the CORESET, where the TCI state is associated with the same TRP as the SRS (explicitly via the TCI state associatedTRP-TCI or implicitly via the order of the TCI states) in the latest slot in which at least one CORESET with at least one TCI state associated with the same TRP as the SRS is monitored by the UE. The "latest slot" is prior to the SRS transmission. The associated TRP with the SRS is indicated by associatedTRP-SRS. Alternatively, the associated CORESET pool may be the same as the scheduling CORESET if the SRS is triggered by DCI. In the case of a DCI-triggered SRS, the default spatial relationship / path loss reference signals may alternatively follow the TCI state / QCL assumption of the scheduling CORESET associated with the same TRP as the SRS.

[0217] This may also apply in the case of dynamic switching between single-TRP and multi-TRP operation. FIG. 25 illustrates an example of SRS default spatial relationships by CORESET TCI state and TRP according to some embodiments. Figure 26 shows another example of SRS default spatial relationships according to CORESET TCI states and TRPs in accordance with some embodiments. In particular, Figure 25 shows the Alt1 operation described above, while Figure 26 shows the Alt2 operation.

[0218] 2.3 Spatial relationships determined based on implicit associations between TCI states and TRPs

[0219] In single DCI multi-TRP operation, for the TCI states of the PDSCH, at least one TCI codepoint includes multiple TCI states. Some constraints may be introduced for the TCI states of the PDSCH. The order of the TCI states may implicitly indicate the association between the TRP and the TCI state. In an example, for those TCI codepoints that include multiple TCI states, the first TCI state may be associated with the same TRP, and the second TCI state may be associated with another TRP. For example, the TCI state IDs as shown above may be used. i,j In this case, for all code points that contain multiple TCI states, the TCI state ID i,1 is associated with TRP #A and TCI State ID i,2 is associated with TRP #B. FIG. 27 illustrates an example of an implicit association between a TCI state and a TRP according to some embodiments.

[0220] In the case of an SRS, the association between a TRP and an SRS may be defined as follows: if the parameter associatedTRP-SRS is set to 0, the SRS is associated with the first TCI state in those TCI codepoints that contain multiple TCI states, e.g., TRP #A, and if associatedTRP-SRS is set to 1, the SRS is associated with the second TCI state, e.g., TRP #B.

[0221] In this case, if enableDefaultBeamPlForSRS is enabled and neither spatial relationship nor path loss reference signal is configured for an SRS, the default spatial relationship / path loss reference signal for the SRS may be applied and determined as follows:

[0222] Alt1: Default SRS spatial relationship / path loss reference signals may dynamically follow indicated TCI states: The default spatial relationship / path loss reference signals of the SRS may follow one of the indicated TCI states / QCL assumptions for PDSCH reception in the latest slot in which PDSCH reception with multiple TCI states is performed. Whether to follow the first state or the second TCI state is further indicated by the parameter associatedTRP-SRS in the RRC message or DCI. In case of an SRS triggered by a DCI, the default spatial relationship / path loss reference signals may alternatively follow the TCI state / QCL assumption of the scheduling CORESET.

[0223] Alt2: The default SRS spatial relationship / path loss reference signal may semi-statically follow one TCI state indicated by one TCI state codepoint: The default spatial relationship / path loss reference signal of the SRS may follow one of the TCI-States corresponding to the lowest codepoint among the TCI codepoints that include multiple TCI states activated for the PDSCH. Whether to follow the first state or the second TCI state may be further indicated by the parameter associatedTRP-SRS in the RRC message or DCI. Alternatively, for an SRS triggered by a DCI, the default spatial relationship / path loss reference signal may follow the TCI state / QCL assumption of the scheduling CORESET.

[0224] FIG. 28 illustrates an example of an SRS default spatial relationship with an implicit association between a TCI and a TRP according to some embodiments. Figure 29 illustrates another example of an SRS default spatial relationship with an implicit association between a TCI and a TRP according to some embodiments. In particular, Figure 28 illustrates the Alt1 operation described above, while Figure 29 illustrates the Alt2 operation.

[0225] 2.4 Spatial relationships determined based on explicit associations between TCI states and TRPs

[0226] A downlink TCI state may be associated with one TRP. For example, a TCI state may be associated with one TRP, e.g., via a TRP ID (logical or physical cell ID). Alternatively, a CORESET pool may be defined, where one CORESET pool represents one TRP, and an association is defined between the TCI state and the CORESET pool. A parameter associatedTRP-TCI may be introduced in TCI-State. Alternatively, the association between the TCI state and the TRP may be configured / updated via the MAC-CE. In another example, the order of the TCI states may implicitly indicate the association between the TRP and the TCI state when one codepoint indicates multiple TCI states. FIG. 30 illustrates an example of an explicit association between a TCI state and a TRP according to some embodiments.

[0227] In this case, if enableDefaultBeamPlForSRS is enabled and neither spatial relationship nor path loss reference signal is configured for an SRS, the default spatial relationship / path loss reference signal for the SRS may be applied and determined as follows:

[0228] Alt1: Default SRS spatial relationship / path loss reference signals may dynamically follow indicated TCI state: The default spatial relationship / path loss reference signals of an SRS may follow the indicated TCI state / QCL assumption for PDSCH reception in the latest slot in which PDSCH reception is performed with one TCI state whose associatedTRP-TCI has the same value as associatedTRP-SRS. In case of an SRS triggered by DCI, the default spatial relationship / path loss reference signals may alternatively follow the TCI state / QCL assumption of the scheduling CORESET.

[0229] Alt2: The default SRS spatial relationship / path loss reference signal may semi-statically follow one TCI state indicated by one TCI state codepoint: The default spatial relationship / path loss reference signal of the SRS may follow the TCI-State with the lowest TCI state ID among those TCI states whose associatedTRP-TCI has the same value as the associatedTRP-SRS. For an SRS indicated by a DCI, the default spatial relationship / path loss reference signal may alternatively follow the TCI state / QCL assumption of the scheduling CORESET. In another example, the default spatial relationship / path loss reference signal of the SRS may follow one TCI state indicated by the lowest TCI state codepoint that includes multiple TCI states. The TCI state is associated with the same TRP as the SRS.

[0230] This may also apply in the case of dynamic switching between single-TRP and multi-TRP operation. FIG. 31 illustrates an example of an SRS default spatial relationship with explicit association between TCI and TRP according to some embodiments. Figure 32 shows another example of an SRS default spatial relationship with an explicit association between a TCI and a TRP according to some embodiments. In particular, Figure 31 shows the Alt1 operation described above, while Figure 32 shows the Alt2 operation.

[0231] 3. Multiple spatial relationships associated with one SRS resource

[0232] In a single DCI multi-TRP scenario, when one SRS resource is configured with multiple spatial relationships, multiple default beams / spatial relationships may be applied to the SRS transmission to reduce overhead. A new RRC parameter, such as enableMultipleDefaultBeam-SRS, may be introduced to indicate whether multiple default spatial relationships / beams are enabled for the SRS transmission. If this parameter is enabled, then spatial relationships and path loss reference signals are not configured for the SRS transmission. Alternatively, spatial relationships and path loss reference signals may be configured but ignored. In this way, additional MAC-CE transmissions for updating the spatial relationships of the SRS transmission may be avoided, and overhead may be reduced. The parameter enableMultipleDefaultBeam-SRS may be defined at the SRS resource set level / SRS resource level.

[0233] When multiple spatial relationships are associated with one SRS resource, the spatial relationships may be associated with different TRPs. In an example, the order of the (default) spatial relationships may implicitly indicate the associated TRPs. For example, a first (default) spatial relationship may be associated with a first TRP, and a second (default) spatial relationship may be associated with a second TRP. In another example, an SRS may be explicitly associated with multiple TRPs via a new RRC parameter.

[0234] The association between the SRS and the TRP in this section (Section 3) is not limited to the default beam operation for the SRS. The association may also be applied in other scenarios of SRS transmission, such as codebook / non-codebook-based transmission. The association may be defined at the SRS resource set level / SRS resource level or in the SRS spatial relationship information.

[0235] The default spatial relationship / default path loss reference signal of the SRS may be determined as described in the following section. The default beam operation may not be applicable to SRS transmission for beam management. The TRP may not trigger SRS transmission, and as mentioned above, one purpose of the SRS is to derive the spatial relationship of the PUSCH transmission. If there is no SRS transmission, then the default SRS spatial relationship is derived assuming that the SRS is transmitted in the first slot of the PUSCH transmission.

[0236] [3.1 Spatial relationship determined based on the association between CORESET and TRP]

[0237] In the case of single DCI multi-TRP operation, a CORESET may also be associated with one TRP. A CORESET pool may also be defined for single DCI multi-TRP operation. The association between a CORESET and a TRP may be defined by an RRC parameter, for example, singleDCI-CORESETPoolIndex; if singleDCI-CORESETPoolIndex is set to 0, the CORESET is transmitted from TRP #A, and if it is set to 1, the CORESET is transmitted from TRP #B.

[0238] In this case, if enableMultipleDefaultBeam-SRS is enabled and neither spatial relationship nor path loss reference signal is configured for an SRS, the default spatial relationship / path loss reference signal for the SRS is applied and determined as follows:

[0239] Alt1: Multiple default SRS spatial relationship / path loss reference signals independently follow the TCI / QCL assumptions of one CORESET: A first default spatial relationship / path loss reference signal of an SRS may follow the TCI state / QCL assumptions of the CORESET with the lowest index among the one or more CORESETs associated with the first TRP in the most recent slot in which the UE monitors the CORESET(s) associated with the first TRP.

[0240] The second default spatial relationship / path loss reference signal of the SRS shall follow the TCI state / QCL assumption of the CORESET(s) associated with the second TRP with the lowest index in the most recent slot in which the CORESET(s) associated with the second TRP are monitored by the UE. FIG. 33 illustrates an example of an SRS with multiple spatial relationships determined by associations between CORESETs and TRPs according to some embodiments.

[0241] 3.2 Spatial relationships determined based on the association between CORESET (multiple TCI states) and TRP

[0242] In the case of single-DCI multi-TRP operation, if a CORESET is configured with multiple activated TCI states, then the TCI state of the CORESET is associated with one TRP. A TCI state may be associated with one TRP, for example, via a TRP ID (e.g., a logical or physical cell ID). Alternatively, a CORESET pool may be defined, where one CORESET pool may represent one TRP, and an association is defined between the TCI state and the CORESET pool. A parameter associatedTRP-TCI may be introduced in TCI-State. Alternatively, the association between the TCI state and the TRP may be configured / updated via the MAC-CE. In another alternative, the order of the TCI states of one CORESET may implicitly indicate the association between the TCI state and the TRP. For example, if one CORESET is configured with two active TCI states, then the first TCI state is associated with the first TRP, and the second TCI state is associated with the second TRP.

[0243] CORESET may be configured with a CORESET pool index or may be configured without a CORESET pool index. In this case, if enableMultipleDefaultBeam-SRS is enabled and neither spatial relations nor path loss reference signals are configured for SRS operation, the default spatial relations / path loss reference signals for SRS operation may be applied and determined as follows:

[0244] Alt1: Multiple default SRS spatial relationship / path loss reference signals independently follow one TCI / QCL assumption of one CORESET: A first default spatial relationship / path loss reference signal of the SRS may follow the TCI state / QCL assumption associated with a first TRP of the lowest-indexed CORESET having at least one TCI state associated with the first TRP in the most recent slot in which one or more such CORESETs are monitored by the UE. A second default spatial relationship / path loss reference signal of the SRS may follow the TCI state / QCL assumption associated with a second TRP of the lowest-indexed CORESET having at least one TCI state associated with the second TRP in the most recent slot in which one or more CORESETs associated with the second TRP are monitored by the UE.

[0245] Alt2: Multiple default SRS spatial relationship / path loss reference signals sequentially follow the TCI / QCL assumptions of one CORESET: The default spatial relationship / path loss reference signals of the SRS may sequentially follow the TCI state / QCL assumptions of the CORESET with the lowest index among those CORESETs configured with multiple activation states associated with different TRPs in the latest slot in which one or more such CORESETs are monitored by the UE.

[0246] Alt3: Multiple default SRS spatial relationship / path loss reference signals sequentially follow the TCI / QCL assumptions of the scheduling CORESET: The SRS default spatial relationship / path loss reference signals sequentially follow the TCI state / QCL assumptions of the scheduling CORESET when the scheduling CORESET is configured with multiple active TCI states.

[0247] For Alt.2 / Alt.3, the SRS may be configured with or without association with a TRP. The TCI state of the CORESET may be configured with or without association with a TRP. Association includes explicit or implicit association. FIG. 34 illustrates an example of an SRS with multiple spatial relationships determined by associations between CORESET TCIs and TRPs according to some embodiments. Figure 35 illustrates another example of an SRS with multiple spatial relationships determined by associations between CORESET TCIs and TRPs in accordance with some embodiments. In particular, Figure 34 illustrates the Alt1 operation described above, while Figure 35 illustrates the Alt2 operation.

[0248] 3.3 Spatial relationships determined based on associations between TCI states and TRPs

[0249] For single DCI multi-TRP operation, if at least one TCI codepoint indicates multiple TCI states, the default spatial relationship / path loss reference signal for the SRS may be determined as follows:

[0250] Alt1: Multiple default SRS spatial relationship / path loss reference signals dynamically follow the indicated TCI state of the PDSCH: The default spatial relationship / path loss reference signal of the SRS sequentially follows the indicated TCI state / QCL assumption of the PDSCH reception in the latest slot in which the PDSCH is received in multiple TCI states indicated by one TCI codepoint.

[0251] Alt2: Multiple default SRS spatial relationship / path loss reference signals semi-statically follow multiple TCI states indicated by one TCI state codepoint: The default spatial relationship / path loss reference signal of the SRS sequentially follows the TCI state corresponding to the lowest codepoint among the TCI codepoints containing multiple TCI states activated for the PDSCH.

[0252] Alt3: Multiple default SRS spatial relationship / path loss reference signals are semi-statically and independently derived: if TCI states are configured in explicit association with TRPs, then a first default spatial relationship / path loss reference signal of the SRS may follow the TCI state with the lowest TCI state ID among those TCI states associated with the first TRP, and a second default spatial relationship / path loss reference signal of the SRS may follow the TCI state with the lowest TCI state ID among those TCI states associated with the second TRP.

[0253] In this embodiment, the SRS may be configured with or without association with a TRP. The TCI state may be configured with or without association with a TRP. The association may include explicit or implicit association. FIG. 36 illustrates an example of an SRS with multiple spatial relationships determined by associations between TCIs and TRPs according to some embodiments. Figure 37 illustrates another example of an SRS with multiple spatial relationships determined by associations between TCIs and TRPs in accordance with some embodiments. In particular, Figure 36 illustrates the Alt1 operation described above, while Figure 37 illustrates the Alt2 operation.

[0254] The methods in Section 2 and Section 3 may be used jointly. For example, if in a system some SRS resources are associated with only one spatial relationship and some SRS resources are associated with multiple spatial relationships, then the method from Section 2 may be used to derive default spatial relationships for those SRSs with one spatial relationship, while the method from Section 3 may be used to derive default spatial relationships for those SRSs with multiple spatial relationships.

[0255] While the embodiments have been described with reference to certain exemplary embodiments, it will be apparent that various modifications and variations can be made to these embodiments without departing from the broader scope of the present disclosure. Accordingly, the specification and drawings are to be regarded in an illustrative sense, and not a restrictive sense. The accompanying drawings, which form a part of this application, show, by way of example, and not by way of limitation, specific embodiments in which the subject matter may be practiced. The illustrated embodiments are described in sufficient detail to enable those skilled in the art to practice the teachings disclosed herein. Other embodiments may be utilized and derived therefrom, such that structural and logical substitutions and changes may be made without departing from the scope of the present disclosure. Accordingly, this detailed description is not to be construed in a limiting sense, and the scope of various embodiments is defined solely by the appended claims, including the full range of equivalents to which such claims are entitled.

[0256] Subject matter may be referred to herein by the term "embodiments," individually and / or collectively, merely for convenience and when more than one inventive concept is actually disclosed, without intending to intentionally limit the scope of the present application to any single inventive concept. Thus, while multiple specific embodiments are shown and described herein, it should be understood that any configuration intended to achieve the same purpose may be substituted for the multiple specific embodiments shown. The present disclosure is intended to cover any and all adaptations or variations of the various embodiments. Combinations of the above embodiments, as well as other embodiments not specifically described herein, will be apparent to those of skill in the art upon reviewing the above description.

[0257] In this document, the terms "a" or "an" are used to include one or more than one, as is common in patent documents, independently of any other instance or use of "at least one" or "one or more." In this document, the term "or" is used to refer to something non-exclusive, or "A or B" is used to include "A but not B," "B but not A," and "A and B," unless otherwise stated. In this document, the terms "including" and "in which" are used as the plain-language equivalents of the respective terms "comprising" and "wherein." Also, in the following claims, the terms "including" and "comprising" are open-ended, i.e., a system, UE, article, composition, formulation, or process that includes multiple elements in addition to those listed after such term in a claim is still considered to be within the scope of that claim. Moreover, in the following claims, the terms "first," "second," and "third," etc., are used merely as labels and are not intended to impose numerical requirements on their objects.

[0258] The Abstract of the Disclosure is provided to comply with 37 CFR § 1.72(b), requiring an abstract that will allow the reader to quickly ascertain the nature of the technical disclosure. The Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, various features may be found grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure should not be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter may consist of less than all features of a single disclosed embodiment. Accordingly, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment. [Other possible items] [Item 1] 1. A Transmit-Receive Point (TRP) device, comprising: determining, by a user equipment (UE), that a single downlink control information (DCI) is to be used for multi-TRP operation for a plurality of TRPs, including a TRP; indicating to the UE a number of spatial relationships to be used for a physical uplink control channel (PUCCH) transmission from the UE; Indicating to the UE a spatial relationship between the transmission of the PUCCH and the reception of a control resource set (CORESET), the spatial relationship depending on multiple spatial relationships used, the spatial relationship being based on an association depending on whether a single spatial relationship or multiple spatial relationships are used, the association being selected from a default association, an explicit association, and an implicit association between a TRP and at least one of the CORESET or a transmission configuration indication (TCI) state; receiving the PUCCH from the UE based on the spatial relationship; and a processing circuit configured to: a memory configured to store the spatial relationship; and An apparatus comprising: [Item 2] Item 1. The apparatus of item 1, wherein, in the case of the single spatial relationship, the processing circuitry is configured to indicate the default association via a radio resource control (RRC) parameter enableDefaultBeamPlForPUCCH. [Item 3] In the case of the single spatial relationship, the processing circuitry may define the spatial relationship at one of a PUCCH resource set level, a PUCCH resource group level, or a PUCCH resource level as: Radio Resource Control (RRC) parameter associatedTRP-PUCCH, Medium Access Control (MAC) Control Element (MAC-CE), a new RRC parameter associatedTRP-PUCCH in the single DCI; or Implicit representation by PUCCH resource group identification (ID) or PUCCH resource configuration ID Item 1. The device according to item 1, configured as indicated by at least one of: [Item 4] 2. The apparatus of claim 1, wherein, in the case of the single spatial relationship, the processing circuitry is configured to avoid configuring the UE with the spatial relationship and path loss reference signal of the PUCCH in response to determining that default beam operation is enabled for the PUCCH. [Item 5] In the case of the single spatial relationship, each of a plurality of CORESETs is associated with a different TRP of the plurality of TRPs, a CORESET pool is defined for the single DCI multi-TRP operation, the association between each CORESET and a TRP is defined by a radio resource control (RRC) parameter singleDCI-CORESETPoolIndex, the PUCCH is associated with a specific CORESET pool via an RRC parameter associatedTRP-PUCCH, and the default spatial relationship is: In the latest slot in which one or more CORESETs whose configured single DCI-CORESETPoolIndex is the same as the CORESET pool associated with the PUCCH are monitored by the UE, the TCI state assumption of the CORESET with the lowest index among the CORESETs whose configured single DCI-CORESETPoolIndex is the same as the CORESET pool associated with the PUCCH; or Scheduling CORESET TCI State Item 1, according to one of the following: [Item 6] In the case of the single spatial relationship: The CORESET is configured with a plurality of TCI states, each of which is associated with a specific TRP via a TRP identifier, or each CORESET pool of a plurality of CORESET pools represents one of the TRPs, and the explicit association is between each TCI state and the corresponding CORESET pool, and the processing circuitry is configured to provide the association in a radio resource control (RRC) parameter associatedTRP-TCI via a TCI state or a medium access control (MAC) control element (MAC-CE), or The order of the TCI states in the CORESET indicates the association between the TCI states and the particular TRP. Item 1, wherein the device is one of: [Item 7] In the case of the single spatial relationship: The processing circuit is configured to indicate to the UE whether the PUCCH follows a TCI state of a particular TRP of a CORESET with a lowest index in a latest slot in which one or more CORESETs are monitored by the UE, or follows a TCI state with a lowest TCI state identifier (ID) among the TCI states of the one or more CORESETs; The association of the TCI state with the specific TRP is indicated via a radio resource control (RRC) parameter associatedTRP-TCI or via the order of the TCI states; The TRP associated with the PUCCH is indicated by an RRC parameter associatedTRP-PUCCH, or a CORESET pool associated with a scheduling CORESET is the same as the scheduling CORESET when the PUCCH is indicated by the single DCI. [Item 8] In the case of the single spatial relationship: At least one TCI codepoint contains multiple TCI states, 2. The apparatus of claim 1, wherein the order of the TCI states implicitly indicates the association between the TRP and the TCI state. [Item 9] or the processing circuit is configured to indicate to the UE that the PUCCH is to follow the specific TCI state among multiple TCI states for Physical Downlink Shared Channel (PDSCH) reception in the latest slot in which PDSCH reception is performed by the UE, the specific TCI state being indicated by a Radio Resource Control (RRC) parameter associatedTRP-PUCCH or the single DCI, so that the default spatial relationship of the single spatial relationship dynamically follows a specific TCI state; or 2. The apparatus of claim 1, wherein the processing circuit is configured to indicate to the UE that the PUCCH is to follow one of a set of TCI states corresponding to a lowest TCI codepoint among TCI codepoints including multiple TCI states, so that the single spatial relationship semi-statically follows another specific TCI state indicated by a TCI state codepoint, and the specific TCI state is indicated by the RRC parameter associatedTRP-PUCCH or by the single DCI. [Item 10] For TCI associations, Each TCI state is associated with a different TRP via a TRP identification (ID), or Each CORESET pool among multiple CORESET pools represents a different TRP, and each TCI state is associated with a different CORESET pool. is one of the The processing circuitry may transmit the TCI association to the UE. Radio Resource Control (RRC) parameter associatedTRP-TCI, a Medium Access Control (MAC) Control Element (MAC-CE) for indicating said association between a TCI state and a TRP; or When one TCI codepoint indicates multiple TCI states, an implicit representation by the order of the TCI states to indicate the association between the TCI states and the TRP. Item 1. The device of item 1, configured as shown in one of the following: [Item 11] or, for the single spatial relationship to dynamically follow a specific TCI state, the processing circuitry is configured to indicate to the UE that the PUCCH follows the specific TCI state among multiple TCI states for Physical Downlink Shared Channel (PDSCH) reception in the latest slot in which PDSCH reception is performed by the UE, the specific TCI state being indicated by a Radio Resource Control (RRC) parameter associatedTRP-TCI having the same value as an RRC parameter associatedTRP-PUCCH or by the single DCI; or 2. The apparatus of claim 1, wherein the processing circuitry is configured to indicate to the UE that the PUCCH will follow one of a set of TCI states corresponding to a lowest TCI state identification (ID) among the TCI states whose RRC parameter associatedTRP-TCI has the same value as the RRC parameter associatedTRP-PUCCH, or another TCI state indicated by a lowest TCI codepoint among TCI codepoints including multiple TCI states whose RRC parameter associatedTRP-TCI has the same value as the RRC parameter associatedTRP-PUCCH, so that the single spatial relationship semi-statically follows another specific TCI state indicated by a TCI state codepoint. [Item 12] the processing circuitry is configured to indicate to the UE that PUCCH resources are configured with multiple spatial relationships via a Radio Resource Control (RRC) parameter enableMultipleDefaultBeam-PUCCH, which, when enabled, indicates that spatial relationships and path loss reference signals are not configured for the PUCCH; or Each CORESET of the plurality of CORESETs is associated with a different TRP, and the processing circuit is configured to indicate the association between the CORESET and the TRP to the UE via a radio resource control (RRC) parameter singleDCI-CORESETPoolIndex. Item 1, wherein the device is at least one of: [Item 13] 2. The apparatus of claim 1, wherein, in the case of the single spatial relationship, the processing circuitry is configured to indicate to the UE that the PUCCH follows the TCI state of the CORESET with the lowest index among the CORESETs associated with a particular TRP in the latest slot in which one or more of the CORESETs associated with the particular TRP are monitored by the UE. [Item 14] In the case of the single spatial relationship: The CORESET is configured with a plurality of TCI states, each of which is associated with a specific TRP via a TRP identifier, or each CORESET pool of a plurality of CORESET pools represents one of the TRPs, and the explicit association is between each TCI state and the corresponding CORESET pool, and the processing circuitry is configured to provide the association in a radio resource control (RRC) parameter associatedTRP-TCI via a TCI state or a medium access control (MAC) control element (MAC-CE), or The order of the TCI states in the CORESET indicates the association between the TCI states and the particular TRP. Item 1, wherein the device is one of: [Item 15] In the case of the default spatial relationship of the single spatial relationship, In a latest slot in which one or more first CORESETs are monitored by the UE, the first default spatial relationship follows a first TCI state associated with a first TRP of a CORESET with a lowest index among the first CORESETs having at least one TCI state associated with the first TRP, and the second default spatial relationship follows a second TCI state associated with a second TRP of a CORESET with a lowest index among the second CORESETs having at least one TCI state associated with the second TRP, in a latest slot in which one or more second CORESETs are monitored by the UE; or The default spatial relationship sequentially follows the TCI state associated with the lowest indexed third CORESET among the third CORESETs having multiple TCI states associated with different TRPs in the latest slot in which one or more third CORESETs are monitored by the UE; or The default spatial relationship follows the TCI states of the scheduling CORESET in sequence when the scheduling CORESET is configured with multiple active TCI states. Item 1, wherein the device is one of: [Item 16] In the case of the single spatial relationship, at least one TCI code point is as follows: a plurality of default spatial relationships dynamically follow a TCI state of a physical downlink shared channel (PDSCH), and the default spatial relationship of a PUCCH sequentially follows the TCI state of a PDSCH reception in a latest slot in which the PDSCH is received in a plurality of TCI states indicated by one of the at least one TCI code point; The plurality of default spatial relationships are semi-statically based on a TCI state corresponding to a lowest TCI codepoint among TCI codepoints including a plurality of TCI states activated for the PDSCH; or The plurality of default spatial relationships are derived semi-statically and independently when the TCI state of the PDSCH is explicitly associated with a TRP. If the TCI indicates multiple conditions, one of which is Next, the first default spatial relationship of the PUCCH follows the TCI state having the first lowest TCI state identifier (ID) among the TCI states associated with the first TRP, and the second default spatial relationship of the PUCCH follows the TCI state having the second lowest TCI state ID among the TCI states associated with the second TRP. [Item 17] 1. A Transmit-Receive Point (TRP) device, comprising: determining, by a user equipment (UE), that a single downlink control information (DCI) is to be used for multi-TRP operation for a plurality of TRPs, including a TRP; Indicating to the UE multiple spatial relationships used for repetitions of a sounding reference signal (SRS), at least some of the SRS resources of an SRS resource set for transmitting repetitions of the SRS with multiple spatial relationships, different spatial relationships of the at least some of the SRS resources targeting different TRPs, and an indication of the multiple spatial relationships provided in the single DCI via a codepoint in an SRI field for aperiodic SRS or a medium access control (MAC) control element (MAC-CE) for aperiodic or semi-persistent SRS; receiving the SRS based on the spatial relationship from the UE; and a processing circuit configured to: a memory configured to store the spatial relationship; and An apparatus comprising: [Item 18] the processing circuitry is further configured to indicate to the UE that each of the SRS resources is associated with a single spatial relationship, whether a default spatial relationship is enabled for the SRS transmission, and that the spatial relationship is not configured for the SRS transmission if the default spatial relationship is enabled; Each SRS is associated with a different TRP, and Radio Resource Control (RRC) parameter associatedTRP-SRS, Triggered by the single DCI, the single DCI including the RRC parameter associatedTRP-SRS; or Implicitly represented by the SRS resource set identifier (ID) The MAC-CE, Item 18. The apparatus of item 17, wherein the SRS resource set level or the SRS resource level is defined by at least one of: [Item 19] 1. A non-transitory computer-readable storage medium storing instructions for execution by one or more processors of a transmit-receive point (TRP), the one or more processors configuring the TRP to: determining, by a user equipment (UE), that a single downlink control information (DCI) is to be used for multi-TRP operation for a plurality of TRPs, including a TRP; indicating to the UE a number of spatial relationships to be used by the UE; Indicating to the UE a spatial relationship between transmission of a physical uplink control channel (PUCCH) and reception of a control resource set (CORESET), the spatial relationship depending on a number of spatial relationships used, the spatial relationship being based on an association depending on whether a single spatial relationship or multiple spatial relationships are used, the association being selected from a default association, an explicit association, and an implicit association between a TRP and at least one of a control resource set (CORESET) or a transmission configuration indication (TCI) state; receiving the PUCCH from the UE based on the spatial relationship; Configure to do, medium. [Item 20] 20. The medium of claim 19, wherein, in the case of the single spatial relationship, the one or more processors configure the TRP to indicate the default association by a radio resource control (RRC) parameter enableDefaultBeamPlForPUCCH when the instructions are executed.

Claims

1. 1. A Transmit-Receive Point (TRP) device, comprising: determining, by a user equipment (UE), that a single downlink control information (DCI) is to be used for multi-TRP operation for multiple TRPs including the TRP; indicating to the UE a number of spatial relationships to be used for physical uplink control channel (PUCCH) transmissions from the UE; Indicating to the UE a spatial relationship between the transmission of the PUCCH and the reception of a control resource set (CORESET), the spatial relationship depending on multiple spatial relationships used, the spatial relationship being based on an association depending on whether a single spatial relationship or multiple spatial relationships are used, the association being selected from a default association, an explicit association, and an implicit association between a TRP and at least one of the CORESET or a transmission configuration indication (TCI) state; receiving the PUCCH from the UE based on the spatial relationship; and a processing circuit configured to: a memory configured to store the spatial relationship; and An apparatus comprising:

2. 2. The apparatus of claim 1, wherein, for the single spatial relationship, the processing circuitry is configured to indicate the default association via a radio resource control (RRC) parameter enableDefaultBeamPlForPUCCH.

3. In the case of the single spatial relationship, the processing circuitry may define the spatial relationship at one of a PUCCH resource set level, a PUCCH resource group level, or a PUCCH resource level as: Radio Resource Control (RRC) parameter associatedTRP-PUCCH, Medium Access Control (MAC) Control Element (MAC-CE); a new RRC parameter associated TRP-PUCCH in the single DCI; or Implicit representation by PUCCH resource group identification (ID) or PUCCH resource configuration ID 3. The apparatus of claim 1, configured as indicated by at least one of:

4. 4. The apparatus of claim 1, wherein, in the case of the single spatial relationship, the processing circuitry is configured to avoid configuring the UE with the spatial relationship and path loss reference signal of the PUCCH in response to determining that default beam operation is enabled for the PUCCH.

5. In the case of the single spatial relationship, each of the multiple CORESETs is associated with a different TRP of the multiple TRPs, a CORESET pool is defined for single DCI multi-TRP operation, the association between each CORESET and a TRP is defined by a radio resource control (RRC) parameter singleDCI-CORESETPoolIndex, and the PUCCH is associated with a specific CORESET pool via an RRC parameter associatedTRP-PUCCH, and the default spatial relationship is: In the latest slot in which one or more CORESETs whose configured single DCI-CORESETPoolIndex is the same as the CORESET pool associated with the PUCCH are monitored by the UE, the TCI state assumption of the lowest indexed CORESET among the CORESETs whose configured single DCI-CORESETPoolIndex is the same as the CORESET pool associated with the PUCCH; or Scheduling CORESET TCI State 5. The device according to claim 1, wherein the device is in accordance with one of the following:

6. In the case of the single spatial relationship: The CORESET is configured with a plurality of TCI states, each of which is associated with a specific TRP via a TRP identifier, or each CORESET pool of a plurality of CORESET pools represents one of the TRPs, and the explicit association is between each TCI state and the corresponding CORESET pool, and the processing circuit is configured to provide the association in a radio resource control (RRC) parameter associatedTRP-TCI via a TCI state or a medium access control (MAC) control element (MAC-CE), or The order of the TCI states in the CORESET indicates the association between the TCI states and the particular TRP.

6. The device according to claim 1, wherein the device is one of:

7. In the case of the single spatial relationship: The processing circuit is configured to indicate to the UE whether the PUCCH follows a TCI state of a specific TRP of a CORESET with a lowest index in a latest slot in which one or more CORESETs are monitored by the UE, or follows a TCI state with a lowest TCI state identifier (ID) among the TCI states of the one or more CORESETs; The association of the TCI state with the specific TRP is indicated via a Radio Resource Control (RRC) parameter associatedTRP-TCI or via the order of the TCI states; 7. The apparatus according to claim 1, wherein the TRP associated with a PUCCH is indicated by an RRC parameter associatedTRP-PUCCH, or a CORESET pool associated with a scheduling CORESET is the same as the scheduling CORESET when the PUCCH is indicated by the single DCI.

8. In the case of the single spatial relationship: At least one TCI codepoint includes multiple TCI states; The apparatus of claim 1 , wherein an order of the plurality of TCI states implicitly indicates the association between the TRP and the TCI state.

9. or to cause the default spatial relationship of the single spatial relationship to dynamically follow a specific TCI state, the processing circuitry is configured to indicate to the UE that the PUCCH follows the specific TCI state among multiple TCI states for Physical Downlink Shared Channel (PDSCH) reception in the latest slot in which PDSCH reception is performed by the UE, the specific TCI state being indicated by a Radio Resource Control (RRC) parameter associatedTRP-PUCCH or the single DCI; or 9. The apparatus of claim 1, wherein the processing circuitry is configured to indicate to the UE that the PUCCH is to follow one of a set of TCI states corresponding to a lowest TCI codepoint among TCI codepoints that include multiple TCI states, such that the single spatial relationship semi-statically follows another specific TCI state indicated by a TCI state codepoint, and the specific TCI state is indicated by the RRC parameter associatedTRP-PUCCH or by the single DCI.

10. In the case of TCI association, Each TCI state is associated with a different TRP via a TRP identification (ID), or Each CORESET pool among multiple CORESET pools represents a different TRP, and each TCI state is associated with a different CORESET pool. It is one of The processing circuitry may be configured to transmit the TCI association to the UE. Radio Resource Control (RRC) parameter associatedTRP-TCI, a Medium Access Control (MAC) Control Element (MAC-CE) for indicating said association between a TCI state and a TRP; or When one TCI codepoint indicates multiple TCI states, an implicit representation by the order of the TCI states to indicate the association between the TCI states and TRPs.

10. The apparatus of claim 1, configured as shown in one of the figures.

11. or, for the single spatial relationship to dynamically follow a specific TCI state, the processing circuitry is configured to indicate to the UE that the PUCCH follows the specific TCI state among multiple TCI states for Physical Downlink Shared Channel (PDSCH) reception in the latest slot in which PDSCH reception is performed by the UE, the specific TCI state being indicated by a Radio Resource Control (RRC) parameter associatedTRP-TCI having the same value as an RRC parameter associatedTRP-PUCCH or by the single DCI; or 11. The apparatus of claim 1, wherein the processing circuitry is configured to indicate to the UE that the PUCCH will follow one of a set of TCI states corresponding to a lowest TCI state identification (ID) among the TCI states whose RRC parameter associatedTRP-TCI has the same value as the RRC parameter associatedTRP-PUCCH, or another TCI state indicated by a lowest TCI codepoint among TCI codepoints including multiple TCI states whose RRC parameter associatedTRP-TCI has the same value as the RRC parameter associatedTRP-PUCCH, so that the single spatial relationship semi-statically follows another specific TCI state indicated by a TCI state codepoint.

12. the processing circuitry is configured to indicate to the UE that PUCCH resources are configured with multiple spatial relationships via a Radio Resource Control (RRC) parameter enableMultipleDefaultBeam-PUCCH, which, when enabled, indicates that spatial relationships and path loss reference signals are not configured for the PUCCH; or Each CORESET of the plurality of CORESETs is associated with a different TRP, and the processing circuit is configured to indicate the association between the CORESET and the TRP to the UE via a radio resource control (RRC) parameter singleDCI-CORESETPoolIndex.

12. The device according to claim 1, wherein the device is at least one of:

13. 13. The apparatus of claim 1, wherein, in the case of the single spatial relationship, the processing circuitry is configured to indicate to the UE that the PUCCH follows the TCI state of a CORESET with a lowest index among the CORESETs associated with a particular TRP in a most recent slot in which one or more of the CORESETs associated with the particular TRP are monitored by the UE.

14. In the case of the single spatial relationship: The CORESET is configured with a plurality of TCI states, each of which is associated with a specific TRP via a TRP identifier, or each CORESET pool of a plurality of CORESET pools represents one of the TRPs, and the explicit association is between each TCI state and the corresponding CORESET pool, and the processing circuit is configured to provide the association in a radio resource control (RRC) parameter associatedTRP-TCI via a TCI state or a medium access control (MAC) control element (MAC-CE), or The order of the TCI states in the CORESET indicates the association between the TCI states and the particular TRP.

14. The device according to claim 1, wherein the device is one of:

15. In the case of the default spatial relationship of the single spatial relationship, In the latest slot in which one or more first CORESETs are monitored by the UE, the first default spatial relationship follows a first TCI state associated with a first TRP of a CORESET with a lowest index among first CORESETs having at least one TCI state associated with the first TRP, and the second default spatial relationship follows a second TCI state associated with a second TRP of a CORESET with a lowest index among second CORESETs having at least one TCI state associated with the second TRP, in the latest slot in which one or more second CORESETs are monitored by the UE; The default spatial relationship sequentially follows the TCI state associated with the lowest indexed CORESET among the third CORESETs having multiple TCI states associated with different TRPs in the latest slot in which one or more third CORESETs are monitored by the UE; or The default spatial relationship follows the TCI states of the scheduling CORESET in sequence when the scheduling CORESET is configured with multiple active TCI states.

15. The device according to claim 1, wherein the device is one of:

16. In the case of the single spatial relationship, at least one TCI code point is as follows: multiple default spatial relationships dynamically follow a TCI state of a physical downlink shared channel (PDSCH), and the multiple default spatial relationships of a PUCCH sequentially follow the TCI state of a PDSCH reception in a latest slot in which the PDSCH is received in multiple TCI states indicated by one of the at least one TCI code point. The plurality of default spatial relationships are semi-statically based on a TCI state corresponding to a lowest TCI codepoint among TCI codepoints comprising a plurality of TCI states activated for the PDSCH; or The multiple default spatial relationships are derived semi-statically and independently when the TCI states of the PDSCH are explicitly associated with TRPs. If the TCI indicates multiple TCI conditions, one of 16. The apparatus of claim 1, wherein the first default spatial relationship of the PUCCH follows a TCI state having a first lowest TCI state identifier (ID) among the TCI states associated with a first TRP, and the second default spatial relationship of the PUCCH follows a TCI state having a second lowest TCI state ID among the TCI states associated with a second TRP.

17. 1. A Transmit-Receive Point (TRP) device, comprising: determining, by a user equipment (UE), that a single downlink control information (DCI) is to be used for multi-TRP operation for multiple TRPs including the TRP; Indicating to the UE multiple spatial relationships used for Sounding Reference Signal (SRS) repetitions, wherein at least some of the SRS resources of an SRS resource set for transmitting the SRS repetitions have multiple different spatial relationships, the multiple different spatial relationships targeting different TRPs, and an indication of the multiple different spatial relationships is provided in the single DCI via a codepoint in an SRI field for aperiodic SRS or a Medium Access Control (MAC) Control Element (MAC-CE) for aperiodic or semi-persistent SRS; receiving the SRS based on the spatial relationship from the UE; and a processing circuit configured to: a memory configured to store the spatial relationship; and An apparatus comprising:

18. the processing circuitry is further configured to indicate to the UE that each of the SRS resources is associated with a single spatial relationship, whether a default spatial relationship is enabled for SRS transmission, and that the spatial relationship is not configured for the SRS transmission if the default spatial relationship is enabled; Each SRS is associated with a different TRP, and Radio Resource Control (RRC) parameters associatedTRP-SRS, Triggered by the single DCI, the single DCI including the RRC parameter associated TRP-SRS; or Implicitly represented by the SRS resource set identifier (ID) the MAC-CE, 18. The apparatus of claim 17, wherein the SRS resource set level is defined by at least one of:

19. A processor at a Transmit-Receive Point (TRP) a procedure for determining, by a user equipment (UE), that a single downlink control information (DCI) is to be used for multi-TRP operation for multiple TRPs including the TRP; a procedure for indicating to the UE a number of spatial relationships to be used for a physical uplink control channel (PUCCH) transmission from the UE; a procedure for indicating to the UE a spatial relationship between the transmission of the PUCCH and the reception of a control resource set (CORESET), the spatial relationship depending on multiple spatial relationships used, the spatial relationship being based on an association depending on whether a single spatial relationship or multiple spatial relationships are used, the association being selected from a default association, an explicit association, and an implicit association between a TRP and at least one of a control resource set (CORESET) or a transmission configuration indication (TCI) state; receiving the PUCCH from the UE based on the spatial relationship; A computer program for executing

20. 20. The computer program product of claim 19, further comprising: configuring the TRP to indicate the default association by a radio resource control (RRC) parameter enableDefaultBeamPlForPUCCH in the case of the single spatial relationship.

21. A computer-readable storage medium storing a computer program according to claim 19 or 20.

22. A processor at a transmit-receive point (TRP), comprising: a procedure for determining, by a user equipment (UE), that a single downlink control information (DCI) is to be used for multi-TRP operation for multiple TRPs including the TRP; a procedure for indicating to the UE multiple spatial relationships used for sounding reference signal (SRS) repetitions, wherein at least some of the SRS resources of an SRS resource set for transmitting the SRS repetitions have multiple different spatial relationships, the multiple different spatial relationships targeting different TRPs, and an indication of the multiple different spatial relationships is provided in the single DCI via a codepoint in an SRI field for aperiodic SRS or a medium access control (MAC) control element (MAC-CE) for aperiodic or semi-persistent SRS; receiving, from the UE, the SRS based on the spatial relationship; A computer program for executing

23. A computer-readable storage medium storing the computer program of claim 22.

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