System and method for TCI indication for multi-TRP transmission

Abstract

The invention relates to user equipment, base station equipment and corresponding methods for the user equipment and the base station. More specifically, the user equipment comprises: a transceiver that, in operation, receives one or more indications indicating a transmission configuration indication (TCI) state; and circuitry, in operation: obtaining one or more TCI state groups of the one or more indicated TCI states, where a TCI state group of the one or more TCI state groups corresponds to one or more spatial directions; and configuring one or more transmission opportunities for the uplink or downlink transmission channel based on the pre-configured association between the TCI state group and the transmission opportunities.

Description

Technical Field

[0001] The present disclosure relates to the transmission and reception of signals in a communication system. Specifically, the present disclosure relates to methods and apparatuses for such transmission and reception. Background Art

[0002] The 3rd Generation Partnership Project (3GPP) works on the technical specifications of next-generation cellular technologies, which are also known as the 5th Generation (5G) including the "New Radio" (NR) Radio Access Technology (RAT), operating in a frequency range up to 100 GHz. NR is a follower of the technologies represented by Long-Term Evolution (LTE) and LTE-Advanced (LTE-A).

[0003] For systems like LTE and NR, further improvements and options can facilitate the efficient operation of the communication system and specific devices related to the system. Summary of the Invention

[0004] One non-limiting and exemplary embodiment facilitates the efficient handling of the configuration of transmission opportunities when a new TCI state is received.

[0005] In one embodiment, the technology disclosed herein is characterized by an apparatus (e.g., a User Equipment (UE)). The apparatus includes a transceiver and circuitry. The transceiver receives, in operation, one or more indications indicating a Transmission Configuration Indicator (TCI) state. The circuitry, in operation: obtains one or more TCI state groups of the one or more indicated TCI states, wherein a TCI state group in the one or more TCI state groups corresponds to one or more spatial directions; and configures one or more transmission opportunities for an uplink or downlink transmission channel based on a pre-configured association between the TCI state group and the transmission opportunity.

[0006] It should be noted that a general or specific embodiment can be implemented as a system, a method, an integrated circuit, a computer program, a storage medium, or any selective combination thereof. For example, an integrated circuit can control the processes of a UE or a network node.

[0007] According to the specification and the drawings, additional benefits and advantages of the disclosed embodiments will become apparent. The benefits and / or advantages can be obtained individually by various embodiments and features of the specification and the drawings, and these embodiments and features do not all need to be provided in order to obtain one or more such benefits and / or advantages. Brief Description of the Drawings

[0008] Hereinafter, exemplary embodiments are described in more detail with reference to the accompanying drawings and figures.

[0009] Figure 1 An exemplary architecture of the 3GPP NR system is shown;

[0010] Figure 2 It is a schematic diagram showing the functional division between the NG-RAN and the 5GC;

[0011] Figure 3 It is a sequence diagram of the RRC connection establishment / reconfiguration process;

[0012] Figure 4 It is a schematic diagram showing the usage scenarios of enhanced mobile broadband (eMBB), massive machine type communication (mMTC), and ultra-reliable and low-latency communication (URLLC);

[0013] Figure 5 It is a block diagram showing an exemplary 5G system architecture for non-roaming;

[0014] Figure 6 It is a block diagram showing the exemplary functional structures of a base station and a user equipment;

[0015] Figure 7 It is a block diagram showing the exemplary functional structure of the circuit processing of the TCI state configuration that can be included in Figure 6 an exemplary user equipment;

[0016] Figure 8 It is a block diagram showing the exemplary functional structure of the TCI state configuration circuit that can be included in Figure 6 an exemplary base station device;

[0017] Figure 9 It is a flowchart showing the exemplary steps performed by a user equipment;

[0018] Figure 10 It is a flowchart showing the exemplary steps performed by a network node;

[0019] Figure 11 It is a schematic diagram showing the update of the TCI state according to a group;

[0020] Figure 12 It is a schematic diagram showing the update of the TCI state by replacing the current TCI state;

[0021] Figure 13 It shows an exemplary association of a list of TCI state groups and TCI states;

[0022] Figure 14 It shows exemplary TCI code points sorted according to TCI state groups;

[0023] Figure 15 It is a second exemplary flowchart showing the exemplary steps performed by a user equipment;

[0024] Figure 16It is a second exemplary flowchart showing exemplary steps performed by a network node. Detailed implementation

[0025] 5G NR system architecture and protocol stack

[0026] 3GPP has been working on the next version of the fifth-generation cellular technology (abbreviated as 5G), including the development of a new radio access technology (NR) operating in the frequency range up to 100 GHz. The first version of the 5G standard was completed at the end of 2017, which allowed the continuation of 5G NR standard-compliant trials and commercial deployments of smartphones.

[0027] The overall system architecture assumes an NG-RAN (Next Generation Radio Access Network) including gNBs, providing NG radio access user plane (SDAP / PDCP / RLC / MAC / PHY) and control plane (RRC) protocol terminations to UEs. gNBs are interconnected with each other via the Xn interface. gNBs are also connected to the NGC (Next Generation Core) via the Next Generation (NG) interface, more specifically, connected to the AMF (Access and Mobility Management Function) (e.g., a specific core entity performing AMF) via the NG-C interface, and connected to the UPF (User Plane Function) (e.g., a specific core entity performing UPF) via the NG-U interface. The NG-RAN architecture is illustrated in Figure 1 (see, for example, 3GPP TS 38.300 v15.6.0, section 4).

[0028] The user plane protocol stack of NR (see, for example, 3GPP TS 38.300, section 4.4.1) includes the PDCP (Packet Data Convergence Protocol, see section 6.4 of TS 38.300), RLC (Radio Link Control, see section 6.3 of TS 38.300), and MAC (Medium Access Control, see section 6.2 of TS 38.300) sublayers, which are terminated in the gNB on the network side. Additionally, a new access stratum (AS) sublayer (SDAP, Service Data Adaptation Protocol) is introduced above the PDCP (see, for example, subclause 6.5 of 3GPP TS 38.300). A control plane protocol stack is also defined for NR (see, for example, TS 38.300, section 4.4.2). An overview of the layer 2 functions is given in subclause 6 of TS38.300. The functions of the PDCP, RLC, and MAC sublayers are listed in sections 6.4, 6.3, and 6.2 of TS 38.300, respectively. The functions of the RRC layer are listed in subclause 7 of TS 38.300.

[0029] For example, the medium access control layer handles logical channel multiplexing and scheduling and scheduling-related functions, including handling different parameter sets.

[0030] The physical layer (PHY) is responsible for, for example, decoding, PHY HARQ processing, modulation, multi-antenna processing, and mapping of signals to appropriate physical time-frequency resources. It also handles the mapping of transport channels to physical channels. The physical layer provides services to the MAC layer in the form of transport channels. A physical channel corresponds to a set of time-frequency resources for the transmission of a specific transport channel, and each transport channel is mapped to a corresponding physical channel. For example, the physical channels are the PRACH (Physical Random Access Channel), PUSCH (Physical Uplink Shared Channel), and PUCCH (Physical Uplink Control Channel) for the uplink, and the PDSCH (Physical Downlink Shared Channel), PDCCH (Physical Downlink Control Channel), and PBCH (Physical Broadcast Channel) for the downlink.

[0031] The use cases / deployment scenarios of NR can include enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), and massive machine type communication (mMTC), which have different requirements in terms of data rate, latency, and coverage. For example, eMBB is expected to support peak data rates (20 Gbps for the downlink and 10 Gbps for the uplink) and user experience data rates, which are approximately three times the data rates provided by IMT-Advanced. On the other hand, in the case of URLLC, more stringent requirements are imposed on ultra-low latency (0.5 ms for both UL and DL for user plane latency) and high reliability (1 - 10^-5 within 1 ms). Finally, mMTC may preferably require a high connection density (1,000,000 devices / km2 in urban environments), large coverage in harsh environments, and extremely long-life batteries (15 years) for low-cost devices.

[0032] Therefore, an OFDM parameter set suitable for one use case (e.g., subcarrier spacing, OFDM symbol duration, cyclic prefix (CP) duration, number of symbols per scheduling interval) may not be well-suited for another use case. For example, compared to mMTC services, low-latency services may preferably require shorter symbol durations (and thus larger subcarrier spacings) and / or fewer symbols per scheduling interval (also known as TTI). In addition, deployment scenarios with large channel delay spreads may preferably require longer CP durations than scenarios with short delay spreads. The subcarrier spacing should be optimized accordingly to maintain a similar CP overhead. NR can support more than one value of subcarrier spacing. Accordingly, subcarrier spacings of 15 kHz, 30 kHz, 60 kHz... are currently being considered. The symbol duration T u and the subcarrier spacing Δf are related by the formula Δf = 1 / T uIs directly related. In a manner similar to that in the LTE system, the term "resource element" can be used to represent the smallest resource unit consisting of a subcarrier of the length of one OFDM / SC-FDMA symbol.

[0033] In the new radio system 5G-NR, for each parameter set and carrier, resource grids of subcarriers and OFDM symbols are defined for the uplink and downlink, respectively. Each element in the resource grid is called a resource element and is identified based on the frequency index in the frequency domain and the symbol position in the time domain (see 3GPP TS 38.211 v15.6.0). For example, downlink and uplink transmissions are organized into frames with a duration of 10 ms, and each frame consists of ten subframes with a duration of 1 ms each. In 5G NR implementations, the number of consecutive OFDM symbols in each subframe depends on the subcarrier spacing configuration. For example, for a 15-kHz subcarrier spacing, a subframe has 14 OFDM symbols (similar to LTE-compliant implementations, assuming a normal cyclic prefix). On the other hand, for a 30-kHz subcarrier spacing, a subframe has two time slots, and each time slot includes 14 OFDM symbols.

[0034] Compared with the LTE parameter sets (subcarrier spacing and symbol length), NR supports multiple different types of subcarrier spacings labeled by the parameter μ (in LTE, there is only a 15-kHz subcarrier spacing, corresponding to μ = 0 in NR). The types of NR parameter sets are summarized in 3GPP TS 38.211, v15.7.0.

[0035] 5G NR Functional Division between NG-RAN and 5GC

[0036] Figure 2 Illustrates the functional division between NG-RAN and 5GC. The NG-RAN logical nodes are gNB or ng-eNB. The 5GC has logical nodes AMF, UPF, and SMF.

[0037] In particular, gNB and ng-eNB host the following main functions:

[0038] - Functions for radio resource management, such as radio bearer control, radio access control, connection mobility control, and dynamic resource allocation (scheduling) to the UE in both the uplink and downlink;

[0039] - IP header compression, encryption, and integrity protection of data;

[0040] - Selecting the AMF when the UE attaches when the route to the AMF cannot be determined from the information provided by the UE;

[0041] - Routing of user plane data to one or more UPFs;

[0042] - Routing of control plane information to the AMF;

[0043] - Connection establishment and release;

[0044] - Scheduling and transmission of paging messages;

[0045] - Scheduling and transmission of system broadcast information (from the AMF or OAM);

[0046] - Measurement and measurement report configuration for mobility and scheduling;

[0047] - Transport-level packet marking in the uplink;

[0048] - Session management;

[0049] - Support for network slicing;

[0050] - QoS flow management and mapping to data radio bearers;

[0051] - Support for UEs in the RRC_INACTIVE state;

[0052] - Distribution function for NAS messages;

[0053] - Radio access network sharing;

[0054] - Dual connectivity;

[0055] - Tight interworking between NR and E-UTRA.

[0056] The Access and Mobility Management Function (AMF) hosts the following main functions:

[0057] - Non-Access Stratum NAS signaling termination;

[0058] - NAS signaling security;

[0059] - Access Stratum AS security control;

[0060] - Internal Core Network CN node signaling for mobility between 3GPP access networks;

[0061] - Idle mode UE reachability (including control and execution of paging retransmission);

[0062] - Registration area management;

[0063] - Support for mobility within and between systems;

[0064] - Access authentication;

[0065] - Access authorization, including checking of roaming rights;

[0066] - Mobility management control (subscription and policy);

[0067] - Support for network slicing;

[0068] - Session Management Function (SMF) selection.

[0069] In addition, the User Plane Function (UPF) hosts the following main functions:

[0070] - Anchor point for mobility within / across Radio Access Technologies (RATs) (when applicable);

[0071] - External PDU session point for interconnection with data networks;

[0072] - Packet routing and forwarding;

[0073] - Packet inspection and user plane part of policy rule enforcement;

[0074] - Traffic usage reporting;

[0075] - Uplink classifier to support routing of traffic flows to data networks;

[0076] - Branch point to support multi-homed PDU sessions;

[0077] - QoS handling in the user plane, such as packet filtering, gating, UL / DL rate enforcement;

[0078] - Uplink information flow verification (SDF to QoS flow mapping);

[0079] - Downlink packet buffering and downlink data notification triggering.

[0080] Finally, the Session Management Function (SMF) hosts the following main functions

[0081] - Session management;

[0082] - UE IP address allocation and management;

[0083] - Selection and control of the UPF function;

[0084] - Configure traffic steering at the User Plane Function (UPF) to route traffic to the appropriate destination;

[0085] - Control part of policy enforcement and QoS;

[0086] - Downlink data notification.

[0087] RRC connection establishment and reconfiguration procedures

[0088] Figure 3Illustrates some interactions between a UE, a gNB, and an AMF (5GC entity) in the context of the UE transitioning from RRC_IDLE to RRC_CONNECTED for the NAS part (see TS 38.300 v15.6.0).

[0089] RRC is the higher layer signaling (protocol) for UE and gNB configuration. Specifically, this transition involves the AMF preparing UE context data (including, for example, PDU session context, security keys, UE radio capabilities, and UE security capabilities, etc.), and sending it to the gNB together with an Initial Context Setup Request. Then, the gNB activates AS security with the UE, which is performed by the gNB sending a SecurityModeCommand message to the UE and the UE responding to the gNB with a SecurityModeComplete message. After that, the gNB performs reconfiguration to set up Signaling Radio Bearer 2 (SRB2) and one or more Data Radio Bearers (DRBs) by sending an RRCReconfiguration message to the UE and receiving an RRCReconfigurationComplete from the UE as a response. For a signaling-only connection, the steps related to RRCReconfiguration are skipped as SRB2 and DRB are not set up. Finally, the gNB notifies the AMF with an Initial Context Setup Response that the establishment process is complete.

[0090] Thus, in the present disclosure, there are provided entities of the fifth generation core (5GC) (e.g., AMF, SMF, etc.), which include a control circuit and a transmitter. The control circuit establishes a next generation (NG) connection with a gNodeB in operation, and the transmitter sends an Initial Context Setup message to the gNodeB via the NG connection in operation to cause the establishment of a signaling radio bearer between the gNodeB and a user equipment (UE). Specifically, the gNodeB sends radio resource control (RRC) signaling containing a resource allocation configuration information element to the UE via the signaling radio bearer. Then, the UE performs uplink transmission or downlink reception based on the resource allocation configuration.

[0091] Usage scenarios for IMT from 2020 and later

[0092] Figure 4Illustrates some use cases of 5G NR. In the 3rd Generation Partnership Project New Radio (3GPP NR), three use cases that have been envisioned by IMT-2020 to support a wide variety of services and applications are being considered. The Phase 1 specifications for enhanced mobile broadband (eMBB) have been included. In addition to further expanding eMBB support, current and future work will also involve the standardization of ultra-reliable and low-latency communication (URLLC) and massive machine-type communication. Figure 4 Illustrates some examples of the envisioned usage scenarios of IMT from 2020 onwards (see, for example, ITU-R M.2083 Figure 2 ).

[0093] The URLLC use case has strict requirements on capabilities such as throughput, latency, and availability, and has been envisioned as one of the enablers for future vertical applications such as wireless control of industrial manufacturing or production processes, remote medical surgery, distribution automation in smart grids, transportation safety, etc. The ultra-reliability of URLLC will be supported by identifying technologies that meet the requirements set in TR 38.913. For NR URLLC in Release 15, the key requirements include a target user plane latency of 0.5 ms for UL (uplink) and a target user plane latency of 0.5 ms for DL (downlink). The general URLLC requirement for a single transmission of a packet is a BLER (block error rate) of 1E-5 for a packet size of 32 bytes, where the user plane latency is 1 ms.

[0094] From the perspective of the physical layer, reliability can be improved in a variety of possible ways. The current scope for improving reliability involves defining a separate CQI table for URLLC, more compact DCI formats, repetition of PDCCH, etc. However, as NR becomes more stable and evolves (for the key requirements of NR URLLC), the scope for achieving ultra-reliability may widen. Specific use cases of NR URLLC in Rel.15 include augmented reality / virtual reality (AR / VR), e-health, e-safety, and mission-critical applications.

[0095] In addition, the technical enhancements targeted by NR URLLC aim at latency improvement and reliability improvement. Technical enhancements for latency improvement include configurable parameter sets, non-slot-based scheduling with flexible mapping, grant-free (configured grant) uplink, slot-level repetition for data channels, and downlink preemption. Preemption means stopping a transmission for which resources have already been allocated, and the allocated resources are used for another transmission that has been requested later but has lower latency / higher priority requirements. Thus, an already authorized transmission is preempted by a later transmission. Preemption can be applied independently of the specific service type. For example, a transmission for service type A (URLLC) can be preempted by a transmission for service type B (such as eMBB). Technical enhancements for reliability improvement include dedicated CQI / MCS tables for a target BLER of 1E-5.

[0096] Use cases for mMTC (massive machine type communication) are characterized by a very large number of connected devices that typically send relatively small amounts of non-latency-sensitive data. The devices are required to be low-cost and have a very long battery life. From the perspective of NR, leveraging very narrow bandwidth portions is a possible solution for energy conservation from the UE's perspective and achieving long battery life.

[0097] As mentioned above, it is desirable to widen the scope of reliability in NR. A key requirement for all scenarios (especially necessary for URLLC and mMTC) is high reliability or ultra-reliability. From both the radio perspective and the network perspective, several mechanisms can be considered to improve reliability. Generally, there are several key potential areas that can help improve reliability. These areas include compact control channel information, data / control channel repetition, and diversity in the frequency, time, and / or spatial domains. These areas are generally applicable to reliability regardless of the specific communication scenario.

[0098] For NR URLLC, other use cases with more stringent requirements have been identified, such as factory automation, the transportation industry, and power distribution, including factory automation, the transportation industry, and power distribution. The more stringent requirements are higher reliability (up to 10 -6 levels), higher availability, packet sizes up to 256 bytes, time synchronization as low as on the order of a few μs, where the value can be 1 μs or a few μs depending on the frequency range, and short latency on the order of approximately 0.5 to 1 ms depending on the use case, especially a target user plane latency of 0.5 ms.

[0099] In addition, for NR URLLC, several technical enhancements have been identified from a physical layer perspective. These include PDCCH (Physical Downlink Control Channel) enhancements related to compact DCI, PDCCH repetition, and increased PDCCH monitoring. In addition, UCI (Uplink Control Information) enhancements are related to enhanced HARQ (Hybrid Automatic Repeat Request) and CSI feedback enhancements. In addition, PUSCH enhancements related to micro-slot level hopping and retransmission / repetition enhancements have been identified. The term "micro-slot" refers to a transmission time interval (TTI) that includes a smaller number of symbols than a slot (a slot including 14 symbols).

[0100] QoS Control

[0101] The 5G QoS (Quality of Service) model is based on QoS flows and supports both QoS flows that require guaranteed flow bitrates (GBR QoS flows) and QoS flows that do not require guaranteed flow bitrates (non-GBR QoS flows). At the NAS level, a QoS flow is thus the finest granularity for QoS differentiation within a PDU session. QoS flows are identified within a PDU session by the QoS flow ID (QFI) carried in the encapsulation header on the NG-U interface.

[0102] For each UE, the 5GC establishes one or more PDU sessions. For each UE, the NG-RAN establishes at least one data radio bearer (DRB) together with the PDU session and may subsequently configure additional DRBs for (one or more) QoS flows for that PDU session (depending on when the NG-RAN does so), as shown, for example, in the reference above Figure 3 indicated. The NG-RAN maps packets belonging to different PDU sessions to different DRBs. NAS-level packet filters in the UE and 5GC associate UL and DL packets with QoS flows, while AS-level mapping rules in the UE and NG-RAN associate UL and DL QoS flows with DRBs.

[0103] Figure 5 illustrates the 5G NR non-roaming reference architecture (see TS23.501 v16.1.0, section 4.23). The application function (AF) (e.g., an external application server hosting 5G services) described exemplarily in Figure 4 interacts with the 3GPP core network to provide services, such as to support the impact of the application on traffic routing, the access network exposure function (NEF), or to interact with the policy framework for policy control (see Policy Control Function, PCF), e.g., QoS control. Based on the operator deployment, application functions considered to be trusted by the operator may be allowed to directly interact with the relevant network functions. Application functions that the operator does not allow direct access to network functions interact with the relevant network functions via the NEF using the external exposure framework.

[0104] Figure 5 Shows other functional units of the 5G architecture, namely the Network Slice Selection Function (NSSF), the Network Repository Function (NRF), the Unified Data Management (UDM), the Authentication Server Function (AUSF), the Access and Mobility Management Function (AMF), the Session Management Function (SMF), and the Data Network (DN), such as operator services, Internet access, or third-party services. All or part of the core network functions and application services can be deployed and run on a cloud computing environment.

[0105] Therefore, in the present disclosure, an application server (e.g., the AF of the 5G architecture) is provided. The application server includes a transmitter and a control circuit. The transmitter, in operation, sends a request including QoS requirements for at least one of URLLC, eMMB, and mMTC services to at least one of the functions (e.g., NEF, AMF, SMF, PCF, UPF, etc.) of the 5GC to establish a PDU session including a radio bearer between the gNodeB and the UE according to the QoS requirements, and the control circuit, in operation, uses the established PDU session to execute the service.

[0106] Control signal

[0107] In the present disclosure, the downlink control signal (information) related to the present disclosure may be a signal (information) sent through the PDCCH of the physical layer, or may be a signal (information) sent through the MAC control element (CE) or RRC of a higher layer. The downlink control signal may be a predefined signal (information).

[0108] The uplink control signal (information) related to the present disclosure may be a signal (information) sent through the PUCCH of the physical layer, or may be a signal (information) sent through the MAC CE or RRC of a higher layer. In addition, the uplink control signal may be a predefined signal (information). The uplink control signal may be replaced by uplink control information (UCI), the first-phase sidelink control information (SCI), or the second-phase SCI.

[0109] Terminal

[0110] A terminal or user terminal or user equipment or mobile station or mobile node is referred to as a user equipment (UE) in LTE and NR. This can be a mobile device or a communication device, such as a wireless phone, a smart phone, a tablet computer, or a USB (Universal Serial Bus) stick with the function of a user equipment. However, the term mobile device is not limited to this. Generally, a relay can also have the function of such a mobile device, and a mobile device can also be used as a relay. For example, a terminal is a physical entity (physical node) within a communication network. Further, the communication device can be any machine type communication device, such as an IoT device, etc. A node can have several functional entities. A functional entity refers to a software or hardware module that implements and / or provides a predetermined set of functions to other functional entities of the same or another node or network. A node can have one or more interfaces that attach the node to a communication facility or medium through which the node can communicate. Similarly, a network entity can have a logical interface that attaches a functional entity to a communication facility or medium through which the network entity can communicate with other functional entities or communication nodes.

[0111] Base station

[0112] In the present disclosure, a base station may be, for example, a transmission reception point (TRP), a cluster head, an access point, a remote radio head (RRH), an eNodeB (eNB), a gNodeB (gNB), a base station (BS), a base transceiver station (BTS), a base station unit, or a gateway. Additionally, in sidelink communication, a terminal may be employed instead of a base station. The base station may be a relay device that relays communication between a higher node and a terminal. The base station may also be a roadside unit. The base station may be a scheduling node or a network node, for example, forming part of a network for providing services to terminals. Specifically, the base station may provide wireless access to terminals. Communication between a terminal and a base station is typically standardized and may be defined by different layers such as PHY, MAC, RRC, etc. In LTE and NR, the radio interface protocol stack includes a physical layer, a medium access layer (MAC), and higher layers. In the control plane, a higher layer protocol, the radio resource control protocol, is provided. Via RRC, the base station may control the configuration of the terminal, and the terminal may communicate with the base station to perform control tasks such as connection and bearer establishment, modification, etc., measurements, and other functions. The term used in LTE is eNB (or eNodeB), while the currently used term in 5G NR is gNB. The term base station or radio base station here refers to a physical entity within a communication network. Like a mobile station, a base station may have several functional entities. A functional entity refers to a software or hardware module that implements and / or provides a predetermined set of functions to the same node or other functional entities of another node or network. The physical entity performs some control tasks regarding communication devices, including one or more of scheduling and configuration. Note that the base station functions and communication device functions may also be integrated within a single device. For example, a mobile terminal may also implement the functions of a base station for other terminals. The term used in LTE is eNB (or eNodeB), while the currently used term in 5G NR is gNB.

[0113] Uplink / Downlink / Sidelink

[0114] The present disclosure may be applied to any one of the uplink, downlink, and sidelink.

[0115] The present disclosure may be applied to, for example, uplink channels such as PUSCH, PUCCH, and PRACH, downlink channels such as PDSCH, PDCCH, and PBCH, and sidelink channels such as the physical sidelink shared channel (PSSCH), the physical sidelink control channel (PSCCH), and the physical sidelink broadcast channel (PSBCH).

[0116] PDCCH, PDSCH, PUSCH, and PUCCH are examples of a downlink control channel, a downlink data channel, an uplink data channel, and an uplink control channel, respectively. PSCCH and PSSCH are examples of a sidelink control channel and a sidelink data channel, respectively. PBCH and PSBCH are examples of a broadcast channel, and PRACH is an example of a random access channel.

[0117] Data Channel / Control Channel

[0118] The present disclosure can be applied to any one of a data channel and a control channel. The channels in the present disclosure can be replaced with a data channel including PDSCH, PUSCH, and PSSCH and / or a control channel including PDCCH, PUCCH, PBCH, PSCCH, and PSBCH.

[0119] Reference Signal

[0120] In the present disclosure, a reference signal is a signal known to both a base station and a mobile station, and each reference signal can be referred to as a reference signal (RS) or sometimes referred to as a pilot signal. The reference signal can be any one of DMRS, a channel state information reference signal (CSI-RS), a tracking reference signal (TRS), a phase tracking reference signal (PTRS), a cell-specific reference signal (CRS), and a sounding reference signal (SRS).

[0121] Time Interval

[0122] In the present disclosure, a time resource unit is not limited to one or a combination of a time slot and a symbol, and can be a time resource unit such as a frame, a superframe, a subframe, a time slot, a time slot sub-time slot, a micro time slot, or a time resource unit such as a symbol, an orthogonal frequency division multiplexing (OFDM) symbol, a single-carrier frequency division multiple access (SC-FDMA) symbol, or other time resource units. The number of symbols included in one time slot is not limited to any number of symbols exemplified in the above-described (one or more) embodiments, and can be other numbers of symbols.

[0123] Frequency Band

[0124] The present disclosure can be applied to any one of an authorized frequency band and an unauthorized frequency band.

[0125] Communication

[0126] The present disclosure can be applied to any one of communication between a base station and a terminal (Uu-link communication), communication between terminals (sidelink communication), and vehicle-to-everything (V2X) communication. The channels in the present disclosure can be replaced by PSCCH, PSSCH, physical sidelink feedback channel (PSFCH), PSBCH, PDCCH, PUCCH, PDSCH, PUSCH, and PBCH.

[0127] In addition, the present disclosure can also be applied to any network in a terrestrial network or a network other than a terrestrial network (NTN: non-terrestrial network) using satellites or high-altitude pseudo-satellites (HAPS). Additionally, the present disclosure can be applied to a network with a large cell size, as well as a terrestrial network with a large delay compared to the symbol length or slot length, such as an ultra-wideband transmission network.

[0128] Antenna port

[0129] An antenna port refers to a logical antenna (antenna group) formed by one or more physical antennas. In other words, an antenna port does not necessarily refer to a single physical antenna, and sometimes refers to an array antenna formed by multiple antennas, etc. For example, there is no definition of how many physical antennas form an antenna port, but an antenna port is defined as the smallest unit that allows a terminal to transmit a reference signal through it. An antenna port can also be defined as the smallest unit for the multiplication of precoding vector weighting.

[0130] Downlink control channel monitoring PDCCH DCI

[0131] Many functions operated by a UE involve monitoring the downlink control channel (e.g., PDCCH, see 3GPP TS38.300 v15.6.0, section 5.2.3) to receive specific control information or data destined for the UE, for example.

[0132] The following gives a non-exhaustive list of these functions:

[0133] - Paging message monitoring function,

[0134] - System information acquisition function,

[0135] - Signaling monitoring operation for discontinuous reception DRX function,

[0136] - Inactive monitoring operation for discontinuous reception DRX function,

[0137] - Random access response reception for random access function,

[0138] - Reordering function of the packet data convergence protocol PDCP layer.

[0139] As described above, PDCCH monitoring is performed by the UE to identify and receive information intended for the UE, such as control information and user traffic (e.g., DCI on the PDCCH and user data on the PDSCH indicated by the PDCCH).

[0140] Control information in the downlink (which may be referred to as downlink control information DCI) has the same purpose in 5G NR as DCI in LTE, i.e., a special set of control information for scheduling, for example, a downlink data channel (e.g., PDSCH) or an uplink data channel (e.g., PUSCH). In 5G NR, a number of different DCI formats have been defined (see Section 7.3.1 of TS38.212 v15.6.0).

[0141] The DCI format represents a predefined format for forming and transmitting the corresponding information. Specifically, DCI formats 0_1 and 1_1 are used to schedule the PUSCH and PDSCH in a cell, respectively.

[0142] PDCCH monitoring for each of these functions is for a specific purpose and thus starts and ends as described. PDCCH monitoring is generally controlled at least based on a timer operated by the UE. The timer has the purpose of controlling PDCCH monitoring, e.g., to limit the maximum amount of time the UE monitors the PDCCH. For example, the UE may not need to monitor the PDCCH indefinitely but can stop monitoring after a period of time to be able to save energy.

[0143] As described above, one of the purposes of DCI on the PDCCH is the dynamic scheduling of resources in the downlink or uplink or even the sidelink. Specifically, some formats of DCI are provided to carry an indication of resources (resource allocation RA) assigned to a data channel for a specific user. The resource allocation may include the specification of resources in the frequency domain and / or the time domain.

[0144] Physical resource block

[0145] Generally, the term "physical resource block" (PRB) refers to the smallest allocable resource unit available for (user) data transmission. In LTE and NR, a PRB has a predefined number (e.g., 12) of consecutive subcarriers in the frequency domain and a predefined number of symbols (e.g., 14 OFDM symbols in LTE) in the time domain.

[0146] Multiple transmit and receive points

[0147] The physical layer in NR can provide multi-antenna operations such as MIMO (Multiple Input, Multiple Output), which can include, for example, using a complex number of or multiple transmission and reception points (multi-TRP). For example, a user equipment can receive data from a complex number of TRP (transmission and reception points), where the complex number of TRP can be controlled by the same or different network nodes. The term multi-point transmission or coordinated multi-point transmission (CoMP) can also be used to include multi-TRP communications that include multi-TRP transmissions.

[0148] In the 3rd Generation Partnership Project (3GPP) for New Radio (NR) Rel.15, basic support for multiple transmission and reception points (multi-TRP) was specified. In NR Rel.16, multi-TRP can be further enhanced according to a new work item on NR MIMO (see RP-182067, “Revised WID (work item description): Enhancements on MIMO for NR”, Samsung, 3GPP TSG RAN (Technical Specification Group Radio Access Network) Meeting#81, Gold Coast, Australia, Sept 10 - 13, 2018).

[0149] For example, multi-TRP operations can be performed by a gNB having different antenna panels or radio heads corresponding to the TRP and different radio frequency units that operate using the respective antennas.

[0150] Moreover, in multi-TRP, several options can be envisioned regarding the positional relationship between the TRP, and the distance between two TRP can vary. For example, the TRP can be close such that the UE receives signals from these TRP from a similar angle. However, the TRP can also be located at a relatively large distance from each other, for example, at remote locations in a network cell. The UE served by two TRP can receive signaling from and send signaling to the respective TRP on uncorrelated channels. Thus, the gain in channel diversity can be optimally utilized.

[0151] Quasi-Co-Location (QCL)

[0152] According to the definition of QCL in Section 5.1.5 of TS38.214, the UE can be configured with a list of up to M TCI state configurations within the higher layer parameter PDSCH-Config to decode the PDSCH according to the detected PDCCH with DCI intended for the UE and a given serving cell, where M depends on the UE capability maxNumberConfiguredTCIstatesPerCC. Each TCI state contains parameters for configuring the quasi-co-location relationship between one or two downlink reference signals and the DM-RS ports of the PDSCH, the DM-RS ports of the PDCCH, or the CSI-RS ports of the CSI-RS resources. The quasi-co-location relationship is configured by the higher layer parameter qcl-Type1 for the first DL RS and qcl-Type2 for the second DL RS (if configured). For the case of two DL RSs, the QCL types should not be the same, regardless of whether the reference is for the same DL RS or different DL RSs. The quasi-co-location type corresponding to each DL RS is given by the higher layer parameter qcl-Type in QCL-Info and can take one of the following values:

[0153] - ‘QCL-TypeA’: {Doppler shift, Doppler spread, mean delay, delay spread}

[0154] - ‘QCL-TypeB’: {Doppler shift, Doppler spread}

[0155] - ‘QCL-TypeC’: {Doppler shift, mean delay}

[0156] - ‘QCL-TypeD’: {Spatial Rx parameter}

[0157] Transmission Configuration Indicator (TCI) state

[0158] Using the DL channel, the gNB indicates to the UE a list of new (indicated) TCI states. Such an indication can be represented by a bit sequence, e.g., a TCI code point. The TCI states in such code points can indicate UL, DL, or joint UL / DL (beam correspondence) spatial (transmission) directions.

[0159] The list (subset) of TCI states to be activated / deactivated is configured by a bitmap. If the bit in a specific position is set to ‘1’, it means it activates the TCI state mapped to the position of that bit. If the bit is set to ‘0’, it means it deactivates the TCI state mapped to the position of that bit.

[0160] The list of bit positions set to '1' is assigned to a small table called a code point, and the maximum size of the code point is 8. This means that only up to 8 bit fields in this MAC CE can be set to '1'. The positions of the '1' bits can be assigned to the code points in ascending order.

[0161] For example, the following fields are set to '1' and all other bits are set to '0'.

[0162] T4 = 1

[0163] T10 = 1

[0164] T11 = 1

[0165] T19 = 1

[0166] T25 = 1

[0167] T40 = 1

[0168] T45 = 1

[0169] T50 = 1

[0170] Then the code points are set as follows.

[0171] Code point 0 = 4

[0172] Code point 1 = 10

[0173] Code point 2 = 11

[0174] Code point 3 = 19

[0175] Code point 4 = 25

[0176] Code point 5 = 40

[0177] Code point 6 = 45

[0178] Code point 7 = 50

[0179] The TCI in DCI 1_1 indicates this code point index.

[0180] RRC signaling (from the base station to the UE) is used to configure up to 128 TCI states for the PDSCH and up to 64 TCI states for the PDCCH. All TCI states are deactivated by default after configuration and after handover.

[0181] In DCI format 1-1 for PDSCH scheduling (section 7.3.1.2.2 of 3GPP TS 38.212 V15.2.0), a field called Transmission Configuration Indicator (TCI) is included, which is used to indicate one of eight TCI states (if configured) using 3 bits. The UE can be configured with a list of up to M TCI states out of the available TCI states (i.e., the above 128 or 64 configured TCIs) configured by the parameter PDSCH-Config, which is configured in RRC (Radio Resource Control) signaling, an example of higher layer signaling in NR. Here, higher means a layer higher than the physical layer. In the example of the above DCI format 1-1, M = 8 corresponds to the maximum 3 bits in the TCI field. Each TCI state includes parameters for configuring the quasi-co-location relationship between one or two downlink reference signals and the DM-RS ports of the PDSCH. For example, the TCI state has the following format:

[0182]

[0183] For example, for a TCI state, two reference signals (e.g., RS A and RS B) can be indicated, and these reference signals can be used to derive some channel propagation parameters.

[0184] Then, the TCI state can be associated with a channel or signal using the tci-StateId. Such a signal / channel is quasi-co-located with RS A and RS B, which means that the same channel propagation parameters derived for RS A and RS B can be used for this RS / channel.

[0185] For the downlink, the reference signals in the TCI state can be CSI-RS or SSB, as shown in the above structure.

[0186] Further information on different QCL types and other relevant information can be found in section 5.1.5 of 3GPP TS 38.214 V15.16.0. Thus, a single PDCCH (single DCI) has up to 3 bits for TCI signaling to indicate one of the QCL assumptions of the eight configured states signaled to the TRP, and the same QCL assumption for other TRPs scheduled by the given PDCCH is assumed. Using this QCL assumption, the TCI state information signaled via DCI is particularly applicable to single TRP transmissions because the same QCL association may not be valid for a different TRP far from each other. Some modifications can facilitate the use of a single PDCCH to support independent TCI state signaling for multiple TRPs. For example, TRPs located geographically apart should have different QCL assumptions, so each TRP has independent TCI state signaling.

[0187] More precisely, Section 5.1.5 of 3GPP TS 38.214 defines that the UE receives an activation command, as described in clause 6.1.3.14 of [10, TS 38.321], for mapping up to 8 TCI states to the code points of the DCI field 'transmission configuration indication'. When the UE is to transmit a PUCCH with HARQ-ACK information in slot n of the PDSCH carrying the activation command, the indicated mapping between the TCI state and the code points of the DCI field 'transmission configuration indication' shall be applied starting from the first slot after the slot, where μ is the SCS configuration of the PUCCH. If tci-PresentInDCI is set to 'enabled' for the CORESET scheduling the PDSCH, and the time offset between the reception of the DL DCI and the corresponding PDSCH is equal to or greater than timeDurationForQCL (if applicable), then after the UE receives the initial higher layer configuration of the TCI state and before receiving the activation command, the UE may assume that the DM-RS ports of the PDSCH of the serving cell are quasi-co-located with the SS / PBCH block determined in the initial access procedure with respect to 'QCL-TypeA' and also with respect to 'QCL-TypeD' if applicable.

[0188] If the UE is configured with the higher layer parameter tci-PresentInDCI set to 'enabled' for the CORESET scheduling the PDSCH, the UE assumes that the TCI field is present in DCI format 1_1 of the PDCCH transmitted on the CORESET. If tci-PresentInDCI is not configured for the CORESET scheduling the PDSCH or the PDSCH is scheduled by DCI format 1_0, and the time offset between the reception of the DL DCI and the reception of the corresponding PDSCH is equal to or greater than the threshold timeDurationForQCL (if applicable) for determining the PDSCH antenna port quasi-co-location, where the threshold is based on the reported UE capabilities [13, TS38.306], then the UE assumes that the TCI state or QCL assumption of the PDSCH is the same as the TCI state or QCL assumption applied to the CORESET used for PDCCH transmission.

[0189] If tci-PresentInDCI is set to 'enabled', then the TCI field in the DCI in the scheduled component carrier points to the active TCI state in the scheduled component carrier or DL BWP, and when the PDSCH is scheduled by DCI format 1_1, the UE shall use the TCI state according to the value of the "Transmission Configuration Indication" field in the PDCCH with the detected DCI for determining the PDSCH antenna port quasi-co-location. If the time offset between the reception of the DL DCI and the corresponding PDSCH is equal to or greater than the threshold timeDurationForQCL, then the UE may assume that the DM-RS ports of the PDSCH of the serving cell are quasi-co-located with the RS in the TCI state with respect to the QCL type parameters given by the indicated TCI state, where the threshold is based on the reported UE capabilities [13, TS 38.306]. When the UE is configured with a single-slot PDSCH, the indicated TCI state shall be based on the active TCI state in the slot with the scheduled PDSCH. When the UE is configured with a multi-slot PDSCH, the indicated TCI state shall be based on the active TCI state in the first slot with the scheduled PDSCH, and the UE shall expect the active TCI state to be the same across the slots with the scheduled PDSCH. When the UE is configured with a CORESET associated with a search space set for cross-carrier scheduling, the UE expects tci-PresentInDci to be set to 'enabled' for the CORESET, and if one or more of the TCI states in the TCI state configured for the serving cell scheduled by the search space set include "QCL-TypeD", then the UE expects the time offset between the reception of the PDCCH detected in the search space set and the corresponding PDSCH to be greater than or equal to the threshold timeDurationForQCL.

[0190] For two cases where tci-PresentInDCI is set to 'enabled' and tci-PresentInDCI is not configured in RRC connected mode, if the offset between the reception of DL DCI and the corresponding PDSCH is less than the threshold timeDurationForQCL, then the UE may assume that the DM-RS ports of the PDSCH in the serving cell are QCL with the QCL parameters of the PDCCH quasi co-location indication for the CORESET, where the CORESET is associated with the monitored search space with the lowest controlResourceSetId in the latest time slot monitored by the UE among one or more CORESETs within the active BWP of the serving cell. In this case, if the "QCL-TypeD" of the PDSCH DM-RS is different from the "QCL-TypeD" of the PDCCH DM-RS that they overlap in at least one symbol, the UE is expected to preferentially receive the PDCCH associated with this CORESET. This also applies to the in-band CA case (when the PDSCH and CORESET are in different component carriers). If none of the configured TCI states of the serving cell that schedules the PDSCH include "QCL-TypeD", the UE shall obtain other QCL assumptions from the indicated TCI state that schedules the PDSCH, regardless of the time offset between the reception of DL DCI and the corresponding PDSCH.

[0191] In NR Release 15, the TCI state (transmission configuration indication) for DL and the spatial relation for UL are signaled in DCI per channel / RS. This signaling may incur signaling overhead, mainly because in many cases, the gNB configures the best beam for all UL / DL channels / RS. The Release 16 beam indication aims to reduce signaling overhead and latency by using the TCI state of the PDCCH as a "common beam" to be used as the default beam applied to PDSCH / PUCCH / SRS / PUSCH.

[0192] In NR Release 17, for single-TRP transmission, a new beam indication scheme called the unified TCI (transmission configuration indication) framework is introduced.

[0193] For single-TRP transmission, a combined TCI state (spatial domain filter that can be used for both uplink and downlink) or a pair of separate DL and UL TCI states are provided to the UE through a three-step process:

[0194] 1. First, the UE is configured by the base station with a list of joint or DL TCI states (joint / DL pool) and a list of UL TCI states (UL pool). These TCI states are referred to as configured TCI states. The first list of joint or DL states can include 128 TCI states, and the second list can include 64 UL TCI states, as described above.

[0195] 2. In step 2, the MAC CE (control element) from the base station activates a set of TCI states from both pools. They are activated in the form of a list of 8 TCI code points, as explained above. The code points include one or more configured TCI states. When RRC unifiedtci-StateType = joint, an example of the list of TCI code points activated by the MAC-CE for a single TRP transmission is:

[0196] Code Point # 0 (Combined / DL TCI 2) 1 (Combined / DL TCI 5) 2 (Combined / DL TCI8) 3 (Combined / DL TCI 21) 4 (Combined / DL TCI 33) 5 (Combined / DL TCI4) 6 (Combined / DL TCI 1) 7 (Combined / DL TCI 9)

[0197] When RRC unifiedtci-StateType = separate (i.e., separate TCI states are configured for DL and UL respectively), an example of the list of TCI code points activated by the MAC-CE for a single TRP transmission is:

[0198] Code Point # 0 (Combined / DL TCI 1; UL TCI 3) 1 (Combined / DL TCI 20; UL TCI 7) 2 (Combined / DL TCI 3; UL TCI 17) 3 (Combined / DL TCI 9; UL TCI 5) 4 (Combined / DL TCI 1; UL TCI 8) 5 (Combined / DL TCI 6; UL TCI 13) 6 (Combined / DL TCI 11; UL TCI 5) 7 (Combined / DL TCI 23; UL TCI 9)

[0199] 3. In step 3, the DCI with format 1_1 or 1_2 (with or without DL data allocation) uses a 3-bit TCI field to select one of the activated TCI code points and thus indicates which TCI states are to be used for downlink and uplink transmissions. Those TCI states are referred to as "indicated" TCI states.

[0200] The DCI with format 1_1 and 1_2 for indicating TCI states can have or without DL data allocation. Thus, scheduling DCI and beam indication DCI can be distinguished.

[0201] For the scheduling DCI, the ACK / NAK of the PDSCH scheduled by the DCI carrying the beam indication can also be used as the ACK of the DCI. For the beam indication DCI, ACK / NACK is also reported. ACK is reported in the PUCCH after a certain number of time slots after the end of PDCCH reception. In the Rel.17 unified TCI framework, the indicated TCI is applied after BeamAppTime_r17 = {1, 2, 4, 7, 14, 28, 42, 56, 70, 84, 98, 112, 224, 336} symbols of the ACK transmission from the beam indication DCI.

[0202] The spatial filter indicated by the DCI will be applied to all DL and UL signals and channels (unless they are configured by RRC not to apply the indicated TCI state); it is applied to:

[0203] - All or a subset of the PDCCHs in the cell,

[0204] - The PDSCH scheduled by the PDCCH,

[0205] - Dynamically or configured grant PUSCH

[0206] - UE-specific PUCCH resources.

[0207] Aperiodic CSI-RS or SRS (limited to certain uses)

[0208] The unified TCI framework in Release 17 only supports single-TRP operation. In addition, it is not allowed to configure both Rel.15 / 16 beam indication and Rel.17 TCI state in the same frequency band. Therefore, Release 18 aims to extend the Rel-17 unified TCI framework to multi-TRP scenarios and avoid having the UE manage both the legacy TCI beam indication scheme and the unified TCI beam indication scheme simultaneously.

[0209] Multi-TRP transmission schemes

[0210] In Releases 16 and 17, there are several multi-TRP transmission schemes. For example, in the single-DCI-based multi-TRP PDSCH repetition scheme, a single DCI sent from one of the TRPs is used to schedule two PDSCH transmissions from two TRPs respectively. The scheduling DCI indicates two TCI states, with each TCI state corresponding to one TRP. This scheme can be a spatial division multiplexing (SDM), frequency division multiplexing (FDM), or time division multiplexing (TDM) scheme.

[0211] For an exemplary SDM, on the same time and frequency resources, the first TRP can send a subset of the layers of the transport block, while the second TRP can send the remaining layers. Antenna ports from different CDM groups are used to send the layers from each TRP, where the first TCI state corresponds to the first CDM group and the second TCI state corresponds to the second CDM group. The dynamic switching between the PDSCH SDM multi-TRP scheme and the single-TRP PDSCH transmission is indicated by using two TCI states in the DCI and using antenna ports from two different CDM groups.

[0212] In exemplary FDM and TDM repetition schemes, two TRPs can repeat the same PDSCH transmission in the frequency domain or the time domain. For the time domain, intra-slot and inter-slot repetitions can be used. Although the FDM scheme has lower latency, for the TDM scheme, the UE needs to receive only one beam at a time, which may become relevant to analog beamforming in frequency range 2 (FR2). Antenna ports from the same CDM group are used for PDSCH transmissions from two TRPs.

[0213] The switching between repetition schemes is done via RRC configuration. In addition, the dynamic switching between single-TRP, SDM multi-TRP schemes, and repetition schemes is done by whether it is a single TCI state or two TCI states and by whether the DMRS in the DCI format scheduling the PDSCH indicates a single CDM group or two CDM groups.

[0214] In Release 17, a single-DCI-based multi-TRP PDCCH repetition scheme is defined. For PDCCH repetition, two PDCCH candidates are linked to each other via the higher layer parameter searchSpaceLinking in the search space set configuration. In addition, these two PDCCH candidates are configured in different search space sets associated with the corresponding CORESET. When the corresponding CORESET has different TCI states, two linked PDCCH repetitions carrying the same DCI are transmitted on two different beams.

[0215] Note that once the UE receives the PDCCH configuration, it can identify the linked PDCCH candidates for repetition. In addition, depending on the configuration of a given UE, it is possible that only some of the SS sets in the SS set are linked for repetition, while other SS sets include separate PDCCH candidates without repetition. Then, the network can dynamically select the linked PDCCH candidates or the separate PDCCH candidates for DCI transmission and thus dynamically switch between single-TRP and multi-TRP transmissions according to reliability and latency requirements. Note that in this scheme, PDCCH candidates originating from CORESETs associated with different CORESET pool index values are not supported.

[0216] In the version 17 multi-TRP PUCCH repetition scheme, PUCCH resources including UL control information (UCI) can be repeated in a time-division multiplexing manner using two spatial relation data per PUCCH resource. When the higher layer parameter PUCCH-nrofSlots is configured, the UE repeats the transmission of UCI on a given PUCCH resource within a specified number of time slots. The PUCCH resources are indicated via MAC-CE messages with multiple spatial relations (FR2) and multiple power control parameters (FR1). Version 17 can support inter-slot repetition and intra-slot repetition. The switch between single-TRP and multi-TRP can be performed dynamically.

[0217] Version 17 enables time-division multiplexed PUSCH repetition towards two TRPs. Both grant-based (mainly single DCI PUSCH repetition types A and B) and configured grant (CG)-based (types 1 and 2) PUSCH repetitions are supported with two UL beams. For single DCI-based multi-TRP PUSCH repetition, codebook (CB)- and non-codebook (NCB)-based PUSCH repetitions are supported by indicating two sounding reference signal (SRS) resource indicators (SRI) and two transmit precoding matrix indicators (TPMI) (for CB-based PUSCH) in DCI format format 0_1 / 0_2. The corresponding SRS resource sets are applied to each SRI, which also allows the use of up to two power control parameter sets.

[0218] The dynamic switch between single-TRP and non-CB / CB multi-TRP PUSCH repetitions is achieved by introducing a new 2-bit DCI field as follows:

[0219]

[0220] Spatial domain and frequency domain multiplexing of PUSCH towards multiple TRPs and simultaneous transmission of multiple PUSCHs are not supported.

[0221] In the Release 17 High-Speed Train (HST)-SFN, a single-DCI-based multi-TRP PDCCH and multi-TRP PDSCH SFN scheme is introduced. Here, the same copy of PDCCH or PDSCH is sent from two TRPs on the same time-frequency resource. It is assumed that TRP-specific SSB / TRS / CSI-RS transmissions are sent in a non-SFN manner for more accurate frequency offset compensation. The SFN-based multi-TRP PDCCH is enabled by combining the activation of a CORESET with two TCI states through RRC configuration and MAC-CE. For the enhanced SFN-based multi-TRP PDSCH, it is achieved through RRC configuration and the indication of two TCI states in the DCI that schedules the PDSCH. Dynamic switching between the SFN-based multi-TRP PDSCH and the single-TRP PDSCH is supported.

[0222] In Release 16, the multi-DCI multi-TRP PDSCH NCJT was introduced to support scenarios with non-ideal backhaul between TRPs, and each TRP uses its own DCI to schedule the PDSCH. Therefore, for multi-DCI-based NC-JT, two PDSCHs can be scheduled simultaneously with two PDCCHs, and the two PDSCHs can be fully, partially, or non-overlapping. To handle HARQ feedback, the CORESET pool concept was introduced. In the RRC configuration, two TRPs are implicitly represented by two different control resource set (CORESET) groups, each CORESET group being identified by the value of the RRC parameter CORESETPoolIndex. The feedback for any received PDSCH associated with the same CORESET pool will feedback their HARQ A / N in the same PUCCH. Subsequently, it was also decided to activate the TCI state of the PDSCH for each CORESET pool, so only one TCI state can be indicated in the DCI that schedules the PDSCH.

[0223] The term

[0224] Hereinafter, the UE, base station, and procedures will be described for the new radio access technology envisioned for the 5G mobile communication system, but these UE, base station, and procedures can also be used in the LTE mobile communication system. Different embodiments and variations will also be explained. The following disclosure is facilitated by the discussions and findings as described above and can be based at least in part thereon.

[0225] Generally, it should be noted that many assumptions have been made herein in order to be able to explain the basic principles of the present disclosure in a clear and understandable manner. However, these assumptions are only understood as examples made herein for illustrative purposes and should not limit the scope of the present disclosure.

[0226] In addition, some of the terms used hereinafter, such as processes, entities, layers, etc., are closely related to those used in the LTE / LTE-A systems or the current 3GPP 5G standardization, even though the specific terms used in the context of the new radio access technology for the next 3GPP 5G communication system have not been fully determined or may ultimately change. Therefore, the terms may be changed in the future without affecting the functions of the embodiments. Thus, those skilled in the art will appreciate that the embodiments and their scope of protection should not be limited to the specific terms used exemplarily herein due to the lack of updated or finally agreed terms, but should be more broadly understood in terms of the functions and concepts underlying the functions and principles constituting the present disclosure.

[0227] Embodiment

[0228] Generally, as already indicated above, it may be desirable to extend the Rel-17 unified TCI framework to multi-TRP scenarios.

[0229] The present disclosure provides network nodes and user equipment, as well as corresponding methods and programs. For example, an integrated circuit may control the processes of a UE or a base station. As Figure 6 shown, the user equipment 610 and the network node 660 may communicate with each other via a wireless channel in a wireless communication system. For example, the user equipment may be an NR user equipment, and the network node may be a base station or a scheduling node, such as an eNB or an NR gNB, particularly a gNB in a non-terrestrial network (NTN) NR system. An example of such a communication system is shown in Figure 6 FIG. The communication system 600 may be a wireless communication system according to the technical specifications of 5G, particularly an NR communication system. However, the present disclosure is not limited to 3GPP NR and may also be applied to other wireless or cellular systems such as NTN.

[0230] Figure 6 FIG. shows a general, simplified, and exemplary block diagram of the user equipment 610 (also referred to as a communication device) and the network node 660. However, generally, in the case of a sidelink connection between two terminals, the scheduling device may also be a terminal. In addition, particularly with regard to the use cases of URLLC, eMBB, and mMTC, the user equipment 610 may also be a sensor device, a wearable device, or a controller of a connected vehicle, or an automated machine in an industrial plant. In addition, the user equipment 610 may be capable of acting as a repeater between the network node 660 and another communication device (e.g., the present disclosure is not limited to a communication "terminal" or a user "terminal").

[0231] The UE and the eNB / gNB use their transceivers 620 (on the UE side) and 670 (on the network node side) to communicate with each other via a (wireless) physical channel 650, respectively. The network node 660 and the terminal 610 together form the communication system 600. The communication system 600 may also include other entities, such asFigure 1 Those entities shown in

[0232] such as Figure 6 (left - hand side), according to a first exemplary embodiment, a user equipment (UE) 610 is provided. The UE 610 includes a transceiver 620 and a circuit 630.

[0233] The transceiver 620 receives an indication of one or more transmission configuration indication (TCI) states in operation. Such TCI states indicated by DCI format are hereinafter referred to as indicated TCI states or new TCI states. Such an indication can be a TCI code point, etc. This indication can be received from a base station. However, the present disclosure is not limited thereto, and TCI can be indicated in device - to - device communication, etc.

[0234] The circuit 630 obtains one or more TCI state groups of one or more new TCI states in operation, where the TCI state groups in the one or more TCI state groups correspond to one or more spatial directions, and configures one or more transmission opportunities of an uplink or downlink transmission channel based on a pre - configured association between the TCI state group and the transmission opportunity.

[0235] The TCI state group can be obtained based on a pre - configured association of the group and (available) TCI states. The available TCI states can correspond to, for example, TCI states configured by RRC signaling, as described in the Transmission Configuration Indication (TCI) State section.

[0236] For example, the UE can receive a configuration indication including an association between one or more TCI state groups and a set of available TCI states. Such an indication can be, for example, an RRC message or any other suitable configuration message. Thus, such an association can be configured at a higher layer.

[0237] For each group associated with a TCI state after updating the TCI state, the corresponding transmission opportunity is configured based on the spatial direction of the group. Such a configuration can include other higher - layer parameters related to multi - TRP transmission, which can also enter the determination of the mapping from the group to the transmission opportunity.

[0238] The UE can receive an indication enabling it to group new TCI states into TCI state groups, where the TCI state groups correspond to a TRP, a spatial direction, a TRP cluster, a set of spatial directions grouped together according to certain criteria (such as AoA (angle of arrival)), etc.

[0239] The UE can configure one or more transmission opportunities of an uplink or downlink channel from one or more TRPs based on a pre - configured association between the TCI state group and the transmission opportunity. For example, the UE can configure two repetitions for the PDSCH channel, each counted as a transmission opportunity.

[0240] For example, in a case where a UE can receive two PDCCHs on two CORESETs (see the multi-TRP transmission scheme section), the UE can be configured to receive the first PDCCH on the CORESET using a TCI state belonging to a first group, and receive the second PDCCH on the CORESET using a TCI state belonging to a second group.

[0241] For example, in a case where a UE can transmit PUCCH repetitions in a TDM manner (see the multi-TRP transmission scheme section), the first transmitted repetition follows a TCI state from a first group, and the second repetition uses a TCI state from a second group. Further, when the UE is indicated with TCI states from two TCI groups and operates in a single-TRP transmission, the UE can be configured to use, for example, a TCI state belonging to a first TCI group rather than a second TCI group.

[0242] Generally, circuit 630 can control transceiver 620 to receive and / or transmit data. This is shown by arrow 625, which schematically represents the interface between circuit 630 and transceiver 620 through which the control is executed. For example, circuit 630 can control 625 transceiver 620 to receive an indication of one or more new TCI states.

[0243] Figure 7 An example functional structure of circuit 630 is shown, particularly circuit 635 for processing TCI state configuration. As shown, TCI state configuration circuit 635 can include TCI state group obtaining circuit 736 and transmission occasion configuration circuit 737. More specifically, circuit 736 can obtain the association of the TCI state group with the new TCI state indicated in the TCI code point. Response transmission circuit 737 can determine when and / or how to (re)configure the transmission occasion.

[0244] Corresponding to the UE described above, a method for configuring a transmission occasion by a user equipment is provided. As Figure 9 shown, the method includes the following steps:

[0245] - Receive (S910) an indication of one or more new transmission configuration indicating TCI states; and

[0246] - Obtain (S920) one or more TCI state groups of one or more new TCI states, where the TCI state group in the one or more TCI state groups corresponds to one or more spatial directions; and - Configure (S930) one or more transmission occasions for an uplink or downlink transmission channel based on a pre-configured association between the TCI state group and the transmission occasion.

[0247] Also as Figure 6As shown in (the right - hand side), a base station 660 is provided. The base station 660 includes a transceiver 670 and a circuit 680. The circuit 680, in operation, generates an indication of one or more indicated transmission configuration indication (TCI) states based on one or more TCI state groups indicating the TCI states, to instruct a user equipment (UE) to configure one or more transmission opportunities of an uplink or downlink transmission channel based on a pre - configured association between the TCI state group and the transmission opportunity, where the TCI state groups in the one or more TCI state groups correspond to one or more spatial directions. The transceiver 670, in operation, transmits an indication of one or more indicated TCI states.

[0248] Generally, the circuit 680 can control the transceiver 670 to receive and / or transmit data. This is shown by arrow 675, which schematically represents the interface between the circuit 680 and the transceiver 670 through which the control is executed. For example, the circuit 680 can instruct 675 the transceiver 670 to send an indication.

[0249] Figure 8 An example functional structure of a TCI state configuration circuit 685 is shown. Specifically, the TCI state configuration circuit 685 may include a TCI code point transmission circuit 836 and a TCI state group association circuit 837. The circuit 836 may be responsible for sending TCI code points. In addition, the circuit 837 may be responsible for sending TCI state group associations.

[0250] In addition, corresponding to the above - mentioned base station, a communication method executed by the base station is provided. As Figure 10 shown, the method includes the following steps:

[0251] - Generate (S1010) an indication of one or more indicated TCI states based on one or more TCI state groups indicating the TCI states, to instruct a user equipment (UE) to configure one or more transmission opportunities for an uplink or downlink transmission channel based on a pre - configured association between the TCI state group and the transmission opportunity, where the TCI state groups in the one or more TCI state groups correspond to one or more spatial directions; and

[0252] - Transmit (S1020) an indication of one or more indicated TCI states.

[0253] The UE 610 may include a transceiver 620 and a (processing) circuit 630, and the network node 660 may include a transceiver 670 and a (processing) circuit 680. The transceiver 670 may further include and / or function as a receiver and / or a transmitter. In other words, in the present disclosure, the term "transceiver" is used to refer to the hardware and software components that allow the communication device 610 or the base station 660 to send and / or receive radio signals via the wireless channel 650. Thus, the transceiver corresponds to a receiver, a transmitter, or a combination of a receiver and a transmitter. Generally, it is assumed that the base station and the communication device are capable of sending and receiving radio signals. However, in some applications, particularly those related to eMBB, mMTC, and URLLC (such as smart homes, smart cities, industrial automation, etc.), it is conceivable that a device such as a sensor only sends signals. Additionally, the term "circuit" includes a processing circuit formed by one or more processors or processing units, etc. The circuits 630 and 680 (or the processing circuits) may be one or more hardware components, such as one or more processors or any LSI. There are input / output points (or nodes) between the transceiver and the processing circuit, and the processing circuit can control the transceiver, i.e., control the receiver and / or the transmitter and exchange receive / send data, through this input / output point (or node) during operation.

[0254] The transceiver functioning as a transmitter and a receiver may include an RF (radio frequency) front end, which includes one or more antennas, amplifiers, RF modulators / demodulators, etc. The processing circuit may implement control tasks, such as controlling the transceiver to send user data and control data provided by the processing circuit and / or receive user data and control data to be further processed by the processing circuit. The processing circuit may also be responsible for performing other processes, such as determining, deciding, calculating, measuring, etc. The transmitter may be responsible for performing the sending process and other related processes. The receiver may be responsible for performing the receiving process and other related processes, such as monitoring the channel.

[0255] Further note that any of the steps / operations / methods described below may be executed or controlled by the circuit 630 (on the UE side) and / or the circuit 680 (on the network node side).

[0256] In further descriptions, unless explicitly stated or the context otherwise indicates, the details and embodiments apply to each of the user equipment, network node, and method. Additionally, note that any of the steps described below may be included in a program as code instructions, and the program may be executed by one or more processors (such as the circuits 630 and / or the circuit 680).

[0257] Figure 15It is a flowchart depicting exemplary steps performed by a UE. For example, the UE receives (S1510) from a gNB a higher layer configuration (e.g., RRC configuration) indicating a set of TCI states. For each TCI state, the set may include an association with a corresponding TCI state group. The UE receives (S1520) on a DL channel a TCI code point that further selects a subset of TCI states from the states configured by the higher layer (i.e., available TCI states) for UL and DL transmissions. The UE obtains (identifies) (S1530) the TCI state group of the TCI state in the TCI code point. The UE updates (S1540) the UL and DL spatial directions using the TCI state indicated in the received TCI code point. The UE uses (S1550) the TCI state group information and other higher layer configurations to map UL or DL transmissions to a single TRP or multiple TRP transmissions with updated spatial directions. If the UE receives (S1520) a new TCI code point, steps S1530 to S1550 may be repeated.

[0258] Figure 16 It is a flowchart depicting exemplary steps performed by a base station (gNB). For example, the base station sends (S1610) a higher layer configuration (e.g., RRC configuration) indicating a set of TCI states to the UE. The base station sends (S1620) on a DL channel a new TCI code point that further selects a subset of TCI states from the higher layer configuration for UL and DL transmissions. The base station uses the TCI code point information sent on the DL to establish one or more TRP connections with the UE for UL or DL transmissions in the updated spatial directions.

[0259] packet

[0260] A TCI state may be associated with a TCI state group. The TCI state groups in these one or more TCI state groups correspond to one or more spatial directions. In particular, a TCI state group may include a set of spatial field filters belonging to one spatial direction or a cluster of spatial directions grouped together, which share some similar channel propagation conditions. For example, a TCI state group may correspond to a TRP. However, the TCI state group is not limited thereto. In other words, such a TRP includes one spatial direction or a cluster of spatial directions grouped together.

[0261] The association between one or more TCI state groups and the set of available TCI states is pre-configured.

[0262] This pre-configuration may be performed by a standard, a configuration indication received by the UE, etc. For example, the UE receives a configuration indication including the association between one or more TCI state groups and the set of available TCI states. Such an indication may be, for example, an RRC message or any other suitable configuration message. Therefore, such an association may be configured at a higher layer.

[0263] The set of available TCI states can correspond to, for example, TCI states defined by RRC signaling, as described in the Transmission Configuration Indication (TCI) states section. In other words, this set of available TCI states corresponds to a pre-configured group of TCI states. The UE can use a subset of the TCI states to establish a link. Such a subset can be indicated by a TCI code point.

[0264] Using the DL channel, the gNB can indicate to the UE a list of active TCI code points, as explained above, where a TCI code point refers to a set of TCI states indicating the DL and UL spatial transmission directions. The TCI states in the code point can correspond to UL, DL, or joint UL / DL (beam correspondence) spatial directions. The UE uses the TCI code point to establish a transmission link (control / data channel) with a single TRP or multiple TRPs according to the number of spatial directions of the TCI code point.

[0265] In a first exemplary embodiment, there are two groups of TCI states. The group of TCI states to which a TCI state may belong can be indicated by a binary parameter. An exemplary binary parameter, TCI_group_index, can indicate that the TCI state belongs to group 0 or group 1. In other words, if the binary parameter has a first value, the TCI state belongs to the first group (e.g., group 0). If the binary parameter has a second value, the TCI state belongs to the second group (e.g., group 1). In other words, a TCI state can be configured with a binary parameter indicating the group.

[0266] The TCI code points for the first exemplary embodiment can include TCI states belonging to TCI group 0 or TCI group 1 or both TCI groups 0 and 1. This allows the UE to establish a single transmission link with a group 0 TRP or a group 1 TRP, or multiple transmission links with both a group 0 TRP and a group 1 TRP.

[0267] In other words, a TCI code point represents one or more TCI states. For example, the TCI states in the code point can belong to group 0. Then, the UE can establish a single transmission link with the TRP corresponding to group 0. For example, the TCI states in the code point can belong to group 1. Then, the UE can establish a single transmission link with the TRP corresponding to group 1. For example, a subset of the TCI states in the code point can belong to group 0, and another subset of the TCI states in the code point can belong to group 1. Then, the UE can establish multiple transmission links with the TRP corresponding to group 0 and the TRP corresponding to group 1.

[0268] For multiple transmission links, any multi-TRP scheme can be used, such as SDM, FDM, TDM, etc. Exemplary multi-TRP schemes defined in Release 16 and / or 17 are given in the multi-TRP transmission scheme section. However, the present invention is not limited to such schemes, and any other multi-TRP scheme can be applied.

[0269] For example, the TCI state in the RRC configuration can be indicated by a binary parameter, indicating group 0 or 1:

[0270]

[0271] The tci-StateId is an identifier used to configure a channel / RS with a TCI state, thereby allowing the channel / RS to be quasi-co-located with the reference signal indicated by the TCI state having this ID. The TCI group signaling in the first exemplary embodiment is compact and causes low overhead. In addition, it allows the UE to perform multi-TRP transmission using the TRPs corresponding to two TCI state groups.

[0272] In the second exemplary embodiment, the TCI state group to which the TCI state can belong can be indicated by a group index parameter. The group index parameter can be an m-bit parameter. For example, the parameter TCI_group_index can indicate that the TCI state belongs to group 0…2 m -1. In other words, the TCI state can be configured with the parameter TCI_group_index indicating the group.

[0273] The TCI code point can include TCI states belonging to only one group of the TCI group {0,…,2 m -1}, or a combination of at most a pre-configured maximum number of TCI state groups. Such a maximum number of TCI state groups can be fixed by the standard, or can be configured by a received configuration indication, etc.

[0274] For example, the parameter Kmax indicates such a pre-configured maximum number of TCI state groups. In an exemplary case, Kmax can be pre-configured to 2 while there are more than two groups (m>1). In such an example, more than two TCI state groups correspond to more than two special directions or TRPs. However, the UE can establish a transmission link with two of the more than two TRPs. The present invention is not limited to such examples. Any value of Kmax can be defined by the standard or configured by a configuration indication.

[0275] For example, such a parameter Kmax can take values in the range of {1…2 m}.

[0276] As in the first exemplary embodiment, this allows the UE to establish a single transmission link or multiple transmission links (space division multiplexed, frequency division multiplexed, time division multiplexed, etc.) with the TRP corresponding to the indicated group.

[0277] The TCI group signaling in the second exemplary embodiment is compact and incurs low overhead, and it allows the UE to perform multi-TRP transmission using TRPs from more than two TCI state groups when m > 1, for example, in a dense deployment environment with a large amount of spatial diversity.

[0278] In the third exemplary embodiment, the higher layer configuration may include one or more lists of TCI states. The one or more lists include TCI states from the set of available TCI states. Each of the one or more lists may be associated with a corresponding group in one or more TCI state groups.

[0279] This is exemplarily depicted in Figure 13 where the first list 1310 includes at least the first TCI state 1311 of the first list and the second TCI state 1312 of the first list. The second list 1320 includes at least the first TCI state 1321 of the second list and the second TCI state 1322 of the second list. The first list 1310 may be marked by the TCI group index 0, and the second list 1320 may be marked by the TCI group index 1.

[0280] Such a list may be pre-configured by a standard or received configuration (e.g., RRC message, etc.).

[0281] For example, the UE is configured by the higher layer with N separate lists of TCI states, where each list is identified by a TCI_group_index. Such a TCI_group_index may take values in the range {0…N - 1} to indicate that the TCI states in a list belong to one of the TCI state groups 0 to N - 1.

[0282] Similar to the second exemplary embodiment, in this third exemplary embodiment, the TCI code point may include TCI states belonging to only one group in the TCI group {0, …, N - 1} or a combination of at most a pre-configured maximum number of TCI state groups. Such a maximum number of TCI state groups may be fixed by a standard or indicated by a received configuration, etc. Such a maximum value may be indicated by the above parameter Kmax.

[0283] In the third exemplary embodiment, such a parameter Kmax may take values, for example, in the range {1…N}.

[0284] This exemplary embodiment defines TCI groups at the level of the TCI list rather than at the level of the TCI state. If the gNB only updates one TCI list for one TCI state group, this can cause less overhead in the higher layer reconfiguration.

[0285] In the fourth exemplary embodiment, the association between the indication and the TCI states in the TCI state group is determined by the sorting of the TCI states in the indication of one or more new TCI states, and the sorting corresponds to a predefined sorting of the TCI state group. Such a predefined sorting can be defined by a standard or configuration, etc.

[0286] Figure 14 An exemplary scenario is shown in which the first TCI state 1410 in the TCI code point 1400 is determined to be associated with group 0. The exemplary first TCI state 1410 in the code point 1400 is a combined UL / DL TCI state. The exemplary second TCI state 1420 in the TCI code point 1400 is a DL state, followed by the exemplary third TCI state 1421 which is a UL state. Therefore, it is determined that the exemplary second TCI state 1420 and the exemplary third TCI state 1421 are associated with group 1.

[0287] In the fourth exemplary embodiment, the TCI code point can be an ordered set of TCI states. The TCI states of TCI group 0 appear first, followed by the TCI states of group 1, in ascending order up to group P-1, where the maximum number of groups P can be fixed by a standard or can be configured by an indication, etc.

[0288] In the fourth exemplary embodiment, there can be rules regarding the allowed TCI code point format, for example, when skipping a group, or when not sending DL or UL information for a certain group. The TCI code point can include an indication to skip one or more groups in the determination of the association. In addition, the TCI code point can include an indication that more than one TCI state can be associated with the current group. Such indications may not necessarily be included in the TCI code point. Such indications can be received independently of the TCI code point, or can be (pre)-configured for the UE by a standard or configuration, etc.

[0289] In the fourth exemplary embodiment, the TCI state group does not require explicit signaling, which can save overhead.

[0290] The TCI grouping as described above, especially the TCI grouping as described for the first, second, third, and fourth exemplary embodiments, can be combined with any update of the current TCI state based on the new TCI states included in the code point (including the update of the TCI state as described below).

[0291] Update of TCI State

[0292] One or more current TCI states may be updated based on indications of one or more new TCI states. Such updates may be performed on a per-group basis or independently of groups. Such groups may be obtained through any suitable grouping implementation, including the first, second, third, and fourth exemplary embodiments described in the previous section.

[0293] In a fifth exemplary embodiment, for each group associated with one or more new TCI states included in an indication (i.e., a code point), the current TCI states associated with the group are updated according to the indication. Such updates update the spatial directions used by the UE for uplink and downlink transmissions.

[0294] This is exemplarily shown in Figure 11 . UE 1103 is configured to use TCI state 2 for UL configuration 1111 to TRP1 1101, and TCI state 1 for DL 1110 with TRP1 1101. Additionally, the UE is configured to use TCI3 as a joint UL / DL configuration 1120 regarding TRP2 1102. TCI states 1 and 2 are associated with group 0 (and thus with TRP1 1101), while TCI state 3 belongs to group 1 (and thus to TRP 2 1102). For example, the gNB may indicate new code points: [TCI5 (group 0), TCI8 (group 0)]. Thus, the UE obtains the groups associated with one or more new TCI states. In the example of Figure 11 , this is group 0. The UE may update the current TCI states of group 0 with the new TCI states of group 0. In other words, the UE replaces TCI1 (group 0), TCI2 (group 0) with states TCI5 (group 0) 1130, TCI8 (group 0) 1131.

[0295] The TCI states in group 0 that the UE is using are updated based on the group 0 TCI states in the code point. Similar updates may be performed for each of groups 1,..., P - 1, where P is the number of TCI state groups present in the indicated TCI code points.

[0296] If one or more current TCI states are associated with groups other than the groups associated with one or more new TCI states, then the one or more current TCI states remain available for the transmission occasion after the update. In other words, the TCI states associated with groups not included in the TCI code point are not updated.

[0297] For example, in Figure 11 , the TCI state (i.e., TCI3) associated with group 1 included in the current TCI states is also included in the updated TCI states.

[0298] In a fourth exemplary embodiment, information about the spatial directions of other TRPs that are not updated is retained.

[0299] The fourth exemplary embodiment can be used for switching from a single TRP to multiple TRPs. If the current TCI state is used to establish multiple transmission links, the fourth exemplary embodiment enables updating the spatial directions of one or more selected TRPs.

[0300] In a sixth exemplary embodiment, the current TCI state is replaced by one or more new TCI states included in an indication (i.e., a code point). Such an update overrides the spatial directions used by the UE for uplink and downlink transmissions.

[0301] If one or more current TCI states are associated with a group other than the group associated with one or more new TCI states, the one or more current TCI states are not available for a transmission occasion after the update. In other words, in the update according to the sixth exemplary embodiment, the UE overrides all current TCI states with the new TCI states included in the code point.

[0302] This is exemplarily shown in Figure 12 . UE 1203 is configured to use TCI state 2 for UL configuration 1211 to TRP1 1201, and TCI state 1 for DL 1210 with TRP1 1201. Additionally, the UE is configured to use TCI3 as a joint UL / DL configuration 1220 regarding TRP2 1202. TCI states 1 and 2 are associated with group 0 (and thus with TRP1 1201), while TCI state 3 belongs to group 1 (and thus to TRP 2 1202). For example, the gNB may indicate new code points: [TCI5 (group 0), TCI8 (group 0)]. Thus, the UE replaces states TCI 1 (group 0), TCI 2 (group 0), TCI 3 (group 1) with new states TCI 5 (group 0) 1230, TCI 8 (group 0) 1231. In the Figure 12 example, multi-TRP transmission has been updated to single-TRP transmission.

[0303] The UE can use the TCI states indicated in the code point to establish a single transmission link or multiple transmission links (space-division multiplexed, frequency-division multiplexed, time-division multiplexed, etc.) with the TRP corresponding to the indicated group.

[0304] The update according to the sixth exemplary embodiment enables dynamic switching between single-TRP transmission and multi-TRP transmission.

[0305] For example, the update method according to the fifth exemplary embodiment or the sixth exemplary embodiment can be selected by the UE by default, via higher layer configuration, or via DCI signaling, etc.

[0306] Hardware and software embodiments of the present disclosure

[0307] The present disclosure can be implemented by software, hardware, or software cooperating with hardware. Each functional block used in the description of each of the above embodiments can be partially or entirely implemented by LSI such as an integrated circuit, and each process described in each embodiment can be partially or entirely controlled by the same LSI or a combination of LSIs. The LSI can be formed as a single chip, or can be formed as one chip to include a part or all of the functional blocks. The LSI can include data input and output coupled thereto. Depending on the difference in the degree of integration, the LSI here can be referred to as an IC, a system LSI, a super LSI, or an ultra LSI. However, the technology for implementing the integrated circuit is not limited to the LSI, and can be implemented by using a dedicated circuit, a general-purpose processor, or a dedicated processor. In addition, an FPGA (Field Programmable Gate Array) that can be programmed after the LSI is manufactured, or a reconfigurable processor that can reconfigure the connection and setting of the circuit units inside the LSI can be used. The present disclosure can be implemented as digital processing or analog processing. If, as a result of the progress of semiconductor technology or other derivative technologies, future integrated circuit technology replaces the LSI, then future integrated circuit technology can be used to integrate the functional blocks. Biotechnology can also be applied.

[0308] The present disclosure can be implemented by any kind of device, apparatus, or system having a communication function, referred to as a communication device.

[0309] The communication device can include a transceiver and a processing / control circuit. The transceiver can include and / or function as a receiver and a transmitter. As a transmitter and a receiver, the transceiver can include an RF (Radio Frequency) module and one or more antennas, and the RF module includes an amplifier, an RF modulator / demodulator, etc.

[0310] Some non-limiting examples of such communication devices include telephones (e.g., cellular (cell) phones, smart phones), tablet computers, personal computers (PCs) (e.g., laptop computers, desktop computers, netbooks), cameras (e.g., digital still / video cameras), digital players (digital audio / video players), wearable devices (e.g., wearable cameras, smart watches, tracking devices), game consoles, digital book readers, remote health / telemedicine (remote health and medical) devices, and vehicles providing a communication function (e.g., automobiles, airplanes, ships), and various combinations thereof.

[0311] The communication device is not limited to being portable or movable, and may also include any kind of non-portable or fixed device, equipment, or system, such as smart home devices (e.g., appliances, lighting, smart meters, control panels), vending machines, and any other "things" in the network of the "Internet of Things (IoT)".

[0312] Communication may include exchanging data via, for example, cellular systems, wireless LAN systems, satellite systems, etc., and various combinations thereof.

[0313] The communication device may include devices such as a controller or a sensor, which are coupled to a communication device that performs the communication functions described in the present disclosure. For example, the communication device may include a controller or a sensor that generates a control signal or a data signal used by the communication device that performs the communication functions of the communication device.

[0314] The communication device may also include infrastructure, such as base stations, access points, and any other device, equipment, or system that communicates with or controls the devices such as those in the above non-limiting examples.

[0315] In addition, various embodiments may also be implemented by means of software modules, which are executed by a processor or directly in hardware. A combination of software module and hardware implementation is also possible. The software module may be stored on any kind of computer-readable storage medium. In particular, according to another embodiment, a non-transitory computer-readable recording medium is provided. The recording medium stores a program that, when executed by one or more processors, causes the one or more processors to perform the steps of the method according to the present disclosure.

[0316] By way of example and not limitation, such computer-readable storage media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, flash memory, or any other medium that can be used to store the desired program code in the form of instructions or data structures and that can be accessed by a computer. In addition, any connection is properly termed a computer-readable medium. For example, if instructions are transmitted using coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of the medium. However, it should be understood that computer-readable storage media and data storage media do not include connections, carrier waves, signals, or other transient media, but rather are directed to non-transitory tangible storage media. As used herein, disk and disc include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Blu-ray disc, where disks typically reproduce data magnetically, while discs reproduce data optically with a laser. Combinations of the above should also be included within the scope of computer-readable media.

[0317] It should also be noted that the various features of different embodiments can be individually or in any combination taken as the subject matter of another embodiment. Those skilled in the art will understand that many variations and / or modifications can be made to the present disclosure as shown in the specific embodiments. Therefore, this embodiment is considered illustrative in all respects and not restrictive.

[0318] Other aspects

[0319] According to a first aspect, there is provided a user equipment (UE). The UE includes a transceiver that, in operation, receives one or more indications of transmission configuration indication (TCI) states. The UE includes circuitry that, in operation: obtains one or more TCI state groups of the one or more indicated TCI states, wherein a TCI state group in the one or more TCI state groups corresponds to one or more spatial directions; and configures one or more transmission opportunities for an uplink or downlink transmission channel based on a preconfigured association between the TCI state group and the transmission opportunity.

[0320] According to a second aspect provided in addition to the first aspect, an association between one or more TCI state groups and a set of available TCI states is preconfigured; and TCI states in the set of available TCI states are associated with groups in the one or more TCI state groups.

[0321] According to a third aspect provided in addition to the second aspect, one or more TCI state groups are two TCI state groups; and in the association between the one or more TCI state groups and the set of available TCI states, each of the two TCI state groups to which a TCI state in the set of available TCI states belongs is indicated by a corresponding value of a binary parameter.

[0322] According to a fourth aspect provided in addition to the second aspect, in the association between the one or more TCI state groups and the set of available TCI states, each of the one or more TCI state groups to which a TCI state in the set of available TCI states belongs is indicated by a corresponding value of a group index parameter.

[0323] According to a fifth aspect provided in addition to the second aspect, the higher layer configuration includes one or more lists, the one or more lists include TCI states in the set of available TCI states; and in the association between the one or more TCI state groups and the set of available TCI states, each of the one or more lists is associated with a corresponding group among the one or more TCI state groups.

[0324] According to a sixth aspect provided in addition to one of the fourth or fifth aspects, the indication of one or more indicated TCI states includes TCI states associated with no more than a preconfigured maximum number of TCI state groups.

[0325] According to a seventh aspect provided in addition to the first aspect, the circuit in operation further determines the association between the TCI states in the indication of one or more indicated TCI states and the TCI state groups by the sorting of the TCI states in the indication of one or more indicated TCI states, the sorting corresponding to a predefined sorting of the TCI state groups.

[0326] According to an eighth aspect provided in addition to one of the first to seventh aspects, the circuit in operation further updates one or more current TCI states based on the indication of one or more indicated TCI states.

[0327] According to a ninth aspect provided in addition to the eighth aspect, when updating the current TCI states, for each group associated with one or more newly indicated TCI states included in the indication, the current TCI states associated with the group are updated according to the indication; if one or more current TCI states are associated with groups other than the groups associated with one or more newly indicated TCI states, the one or more current TCI states remain available for transmission opportunities after the update.

[0328] According to a tenth aspect provided in addition to the eighth aspect, when updating the current TCI state, replace the current TCI state with one or more indicated TCI states according to an indication; if one or more current TCI states are associated with a group other than the group associated with one or more indicated TCI states, the one or more current TCI states are unavailable for a transmission occasion after the update.

[0329] According to an eleventh aspect provided in addition to one of the first to tenth aspects, in the configuration of one or more transmission occasions, for each group associated therewith after the TCI state update, the corresponding transmission occasion is configured based on the spatial direction of the group.

[0330] According to a twelfth aspect provided in addition to one of the first to tenth aspects, the circuit further receives a configuration indication in operation, the configuration indication including the association between one or more TCI state groups and a set of available TCI states.

[0331] According to a thirteenth aspect, a method for configuring a transmission occasion by a user equipment (UE) is provided. The method includes the following steps:

[0332] - Receiving an indication indicating one or more transmission configuration indication TCI states; and

[0333] - Obtaining one or more TCI state groups of one or more indicated TCI states, wherein the TCI state groups in the one or more TCI state groups correspond to one or more spatial directions; and

[0334] - Configuring one or more transmission occasions for an uplink or downlink transmission channel based on a preconfigured association between the TCI state group and the transmission occasion.

[0335] According to a fourteenth aspect, a base station is provided. The base station includes a circuit which, in operation: generates an indication of one or more indicated TCI states based on one or more TCI state groups of one or more indicated transmission configuration indication TCI states to instruct a user equipment UE to configure one or more transmission occasions for an uplink or downlink transmission channel based on a preconfigured association between the TCI state group and the transmission occasion, wherein the TCI state groups in the one or more TCI state groups correspond to one or more spatial directions. The base station includes a transceiver which, in operation: transmits an indication of one or more indicated TCI states.

[0336] According to a fifteenth aspect provided in addition to the fourteenth aspect, the circuit further generates a configuration indication in operation, the configuration indication including the association between one or more TCI state groups and a set of available TCI states. For example, the transceiver further transmits the configuration indication in operation.

[0337] According to a sixteenth aspect provided in addition to one of the fourteenth or fifteenth aspects, in operation, the circuit further configures one or more transmission opportunities for an uplink or downlink transmission channel with a UE based on a pre-configured association between a TCI state group and a transmission opportunity.

[0338] According to a seventeenth aspect, there is provided a method for a base station to send a configuration indication. The method includes the following steps:

[0339] - Generating an indication of one or more indicated TCI states based on one or more TCI state groups indicating a transmission configuration indicating a TCI state, to instruct a user equipment UE to configure one or more transmission opportunities for an uplink or downlink transmission channel based on a pre-configured association between a TCI state group and a transmission opportunity, wherein a TCI state group in the one or more TCI state groups corresponds to one or more spatial directions; and

[0340] - Sending an indication of one or more indicated TCI states.

[0341] According to an eighteenth aspect, there is provided an integrated circuit that controls a process of a user equipment in operation, and the process includes the following steps performed by the user equipment:

[0342] - Receiving an indication of one or more indicated transmission configurations indicating a TCI state; and

[0343] - Obtaining one or more TCI state groups of one or more indicated TCI states, wherein a TCI state group in the one or more TCI state groups corresponds to one or more spatial directions; and

[0344] - Configuring one or more transmission opportunities for an uplink or downlink transmission channel based on a pre-configured association between a TCI state group and a transmission opportunity.

[0345] According to a nineteenth aspect, there is provided an integrated circuit that controls a process of a base station in operation, and the process includes the following steps performed by a network node:

[0346] - Generating an indication of one or more indicated TCI states based on one or more TCI state groups indicating a transmission configuration indicating a TCI state, to instruct a user equipment UE to configure one or more transmission opportunities for an uplink or downlink transmission channel based on a pre-configured association between a TCI state group and a transmission opportunity, wherein a TCI state group in the one or more TCI state groups corresponds to one or more spatial directions; and

[0347] - Sending an indication of one or more indicated TCI states.

[0348] According to a twentieth aspect, a program stored on a storage medium and including code instructions, when the code instructions are executed on one or more processors of a user equipment, cause the one or more processors to perform the following steps:

[0349] - Receive one or more indications indicating a transmission configuration indication (TCI) state; and

[0350] - Obtain one or more TCI state groups of the one or more indicated TCI states, where the TCI state groups in the one or more TCI state groups correspond to one or more spatial directions; and

[0351] - Configure one or more transmission opportunities for an uplink or downlink transmission channel based on a pre-configured association between the TCI state group and the transmission opportunity.

[0352] According to a twenty-first aspect, a program stored on a storage medium and including code instructions, when the code instructions are executed on one or more processors of a base station, cause the one or more processors to perform the following steps:

[0353] - Generate an indication of the one or more indicated TCI states based on one or more TCI state groups of the one or more indicated transmission configuration indication (TCI) states, to instruct a user equipment (UE) to configure one or more transmission opportunities for an uplink or downlink transmission channel based on a pre-configured association between the TCI state group and the transmission opportunity, where the TCI state groups in the one or more TCI state groups correspond to one or more spatial directions; and

[0354] - Transmit an indication of the one or more indicated TCI states.

[0355] In summary, the present disclosure relates to a user equipment, a base station equipment, and corresponding methods for the user equipment and the base station. More specifically, the user equipment includes: a transceiver that receives an indication of one or more indicated transmission configuration indication (TCI) states in operation; and a circuit that, in operation: obtains one or more TCI state groups of the one or more indicated TCI states, where the TCI state groups in the one or more TCI state groups correspond to one or more spatial directions; and configures one or more transmission opportunities for an uplink or downlink transmission channel based on a pre-configured association between the TCI state group and the transmission opportunity.

Claims

1. A user equipment (UE), comprising: a transceiver that receives an indication of one or more transmission configuration indication (TCI) states; and a circuit that: obtains one or more TCI state groups of the one or more indicated TCI states, wherein a TCI state group in the one or more TCI state groups corresponds to one or more spatial directions; and configures one or more transmission opportunities for an uplink or downlink transmission channel based on a pre-configured association between the TCI state group and the transmission opportunity.

2. The UE according to claim 1, wherein the association between the one or more TCI state groups and a set of available TCI states is pre-configured; and a TCI state in the set of available TCI states is associated with a group in the one or more TCI state groups.

3. The UE according to claim 2, wherein the one or more TCI state groups are two TCI state groups; and in the association between the one or more TCI state groups and the set of available TCI states, each group in the two TCI state groups to which a TCI state in the set of available TCI states belongs is indicated by a corresponding value of a binary parameter.

4. The UE according to claim 2, wherein in the association between the one or more TCI state groups and the set of available TCI states, each group in the one or more TCI state groups to which a TCI state in the set of available TCI states belongs is indicated by a corresponding value of a group index parameter.

5. The UE according to claim 2, wherein a higher layer configuration includes one or more lists that include TCI states in the set of available TCI states; and in the association between the one or more TCI state groups and the set of available TCI states, each list in the one or more lists is associated with a corresponding group in the one or more TCI state groups.

6. The UE according to any one of claims 4 or 5, wherein the indication of the one or more indicated TCI states includes TCI states associated with no more than a pre-configured maximum number of TCI state groups.

7. The UE according to claim 1, wherein the circuit further determines the association between the TCI states in the indication and the TCI state groups by sorting the TCI states in the indication of the one or more indicated TCI states, the sorting corresponding to a predefined sorting of the TCI state groups.

8. The UE according to any one of claims 1 to 7, wherein the circuit further updates one or more current TCI states based on the indication of the one or more indicated TCI states.

9. The UE according to claim 8, wherein in the update of the current TCI states, for each group associated with one or more of the indicated TCI states included in the indication, the current TCI state associated with the group is updated according to the indication; If one or more current TCI states are associated with a group other than the group associated with the one or more indicated TCI states, the one or more current TCI states remain available for a transmission occasion after the update.

10. The UE according to claim 8, wherein in the update of the current TCI state, the current TCI state is replaced by the one or more indicated TCI states according to the indication; If one or more current TCI states are associated with a group other than the group associated with the one or more indicated TCI states, the one or more current TCI states are not available for a transmission occasion after the update.

11. The UE according to any one of claims 1 to 10, wherein in the configuration of the one or more transmission occasions, for each group associated with the state after the update of the TCI state, the corresponding transmission occasion is configured based on the spatial direction of the group.

12. The UE according to any one of claims 1 to 10, wherein the circuit further receives a configuration indication, the configuration indication including an association between the one or more TCI state groups and the set of available TCI states.

13. A method for configuring a transmission occasion by a user equipment UE, the method comprises: receiving an indication of one or more indicated transmission configuration indication TCI states; and obtaining one or more TCI state groups of the one or more indicated TCI states, wherein the TCI state groups in the one or more TCI state groups correspond to one or more spatial directions; and configuring one or more transmission occasions for an uplink or downlink transmission channel based on a preconfigured association between the TCI state group and the transmission occasion.

14. A base station, comprises: a circuit, the circuit: generating an indication of the one or more indicated TCI states based on one or more TCI state groups of the one or more indicated transmission configuration indication TCI states to instruct a user equipment UE to configure one or more transmission occasions for an uplink or downlink transmission channel based on a preconfigured association between the TCI state group and the transmission occasion, wherein the TCI state groups in the one or more TCI state groups correspond to one or more spatial directions; and a transceiver, the transceiver: sending the indication of the one or more indicated transmission configuration indication TCI states.

15. The base station according to claim 15, wherein the circuit further generates a configuration indication, the configuration indication including an association between the one or more TCI state groups and the set of available TCI states. For example, the transceiver further sends the configuration indication.

16. The base station according to any one of claims 15 or 16, wherein the circuit further configures one or more transmission occasions for an uplink or downlink transmission channel with the UE based on the preconfigured association between the TCI state group and the transmission occasion.

17. A method for a base station to send a configuration indication, the method comprises Generate an indication of the one or more indicated transmission configuration indication (TCI) states based on one or more TCI state groups indicating the TCI states, to instruct a user equipment (UE) to configure one or more transmission opportunities for an uplink or downlink transmission channel based on a preconfigured association between the TCI state group and the transmission opportunity. Wherein a TCI state group among the one or more TCI state groups corresponds to one or more spatial directions; and transmit the indication of the one or more indicated TCI states.

18. An integrated circuit that controls a process of a user equipment, the process comprising the following steps performed by the user equipment: - Receive an indication of the one or more indicated TCI states; and - Obtain one or more TCI state groups of the one or more indicated TCI states, wherein a TCI state group among the one or more TCI state groups corresponds to one or more spatial directions; and - Configure one or more transmission opportunities for an uplink or downlink transmission channel based on a preconfigured association between the TCI state group and the transmission opportunity.

19. An integrated circuit that controls a process of a base station, the process comprising the following steps performed by a network node: - Generate an indication of the one or more indicated TCI states based on one or more TCI state groups indicating the TCI states, to instruct a UE to configure one or more transmission opportunities for an uplink or downlink transmission channel based on a preconfigured association between the TCI state group and the transmission opportunity, wherein a TCI state group among the one or more TCI state groups corresponds to one or more spatial directions; and - Transmit the indication of the one or more indicated TCI states.

20. A program stored on a storage medium and comprising code instructions that, when executed on one or more processors of a user equipment, cause the one or more processors to perform the following steps: - Receive an indication of the one or more indicated TCI states; and - Obtain one or more TCI state groups of the one or more indicated TCI states, wherein a TCI state group among the one or more TCI state groups corresponds to one or more spatial directions; and - Configure one or more transmission opportunities for an uplink or downlink transmission channel based on a preconfigured association between the TCI state group and the transmission opportunity.

21. A program stored on a storage medium and comprising code instructions that, when executed on one or more processors of a base station, cause the one or more processors to perform the following steps: - Generate an indication of the one or more indicated TCI states based on one or more TCI state groups that indicate a transmission configuration indication (TCI) state, to instruct a user equipment (UE) to configure one or more transmission opportunities for an uplink or downlink transmission channel based on a pre-configured association between the TCI state group and the transmission opportunity, wherein the TCI state group in the one or more TCI state groups corresponds to one or more spatial directions; and - Transmit the indication of the one or more indicated TCI states.

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