User equipment and scheduling node

Abstract

The present disclosure relates to a user equipment, UE, and a scheduling node, and corresponding methods. Specifically, a downlink control information, DCI, signaling carries a transmission configuration indication, TCI, indicator specifying a configuration of two or more TCI states; and an indication of time domain resources for a transmission and an association of the time domain resources to the two or more TCI states, wherein each time domain resource is associated with one of the two or more TCI states; wherein the transceiver receives or transmits data on the time domain resources associated with the respective TCI state for each of the two or more TCI states.

Description

TECHNICAL FIELD

[0001] The present invention relates to transmission and reception of signals in a communication system. In particular, the present invention relates to methods and apparatuses for such transmission and reception. BACKGROUND

[0002] The Third Generation Partnership Project (3GPP) is committed to the technical specification of next generation cellular technology, also referred to as the Fifth Generation (5G), including a “New Radio” (NR) Radio Access Technology (RAT) that operates in frequency ranges up to 100 GHz. NR is a successor to Long Term Evolution (LTE) and LTE-Advanced (LTE-A) technology.

[0003] For systems such as LTE, LTE-A, and NR, further modifications and options can facilitate efficient operation of the communication system and particular devices related to the system. SUMMARY

[0004] One non-limiting and exemplary embodiment facilitates efficient utilization of resources, including efficient signaling of time domain resources for multiple transmission / reception points (TRPs), i.e., for multiple transmission configuration indication (TCI) states.

[0005] In one embodiment, the technical features disclosed herein are directed to a user equipment, UE, comprising: a transceiver to receive downlink control information, DCI, signaling; and a processor to obtain, from the DCI signaling: a transmission configuration indication, TCI, indicator that specifies that two or more TCI states are configured; and an indication of time domain resources for transmission and an association of the time domain resources to the two or more TCI states, wherein each time domain resource is associated with one of the two or more TCI states; wherein the transceiver receives or transmits data on the time domain resources associated with the respective TCI state for each of the two or more TCI states.

[0006] It should be noted that general or specific embodiments can be implemented as a system, a method, an integrated circuit, a computer program, a storage medium, or any selective combination thereof.

[0007] Additional benefits and advantages of the disclosed embodiments will become apparent from the specification and drawings. Benefits and / or advantages can be realized by one or more embodiments and features, and each of the embodiments and features do not need to provide one or more of these benefits and / or advantages. BRIEF DESCRIPTION OF DRAWINGS

[0008] In the following, exemplary embodiments are described in more detail with reference to the accompanying drawings and pictures.

[0009] Figure 1is a diagram illustrating an exemplary architecture of a 3GPP NR system;

[0010] Figure 2 is a block diagram illustrating exemplary user and control plane protocol architecture for LTE eNB, gNB and UE;

[0011] Figure 3 is a diagram illustrating functional split between NG-RAN and 5GC;

[0012] Figure 4 is a sequence diagram of an RRC connection establishment / reconfiguration procedure;

[0013] Figure 5 is a diagram illustrating usage scenarios for enhanced mobile broadband, massive machine type communication (mMTC), and ultra-reliable low-latency

[0014] Figure 6 is a block diagram illustrating an exemplary 5G system architecture;

[0015] Figure 7 is a block diagram illustrating a user equipment (UE) and a scheduling node (base station) communicating over a channel;

[0016] Figure 8 is a block diagram illustrating a processing circuit portion of a user equipment (UE);

[0017] Figure 9 is a block diagram illustrating a processing circuit portion of a base station;

[0018] Figure 10 is a flow diagram illustrating a method performed in a UE;

[0019] Figure 11 is a diagram illustrating a first example of time domain resources for multiple TRPs;

[0020] Figure 12 is a diagram illustrating a second example of time domain resources for multiple TRPs;

[0021] Figure 13 is a diagram illustrating a third example of time domain resources for multiple TRPs;

[0022] Figure 14 is a diagram illustrating a fourth example of time domain resources for multiple TRPs;

[0023] Figure 15 is a diagram illustrating a fifth example of time domain resources for multiple TRPs;

[0024] Figure 16 is a diagram illustrating a sixth example of time domain resources for multiple TRPs;

[0025] Figure 17 is a diagram illustrating a seventh example of time domain resources of multiple TRPs; and

[0026] Figure 18 is a flowchart illustrating a method performed at a UE and a base station. DETAILED DESCRIPTION

[0027] 5G NR System Architecture and Protocol Stack

[0028] 3GPP has been working on the next releases of the fifth generation cellular technology (5G) including the development of a new radio access technology (NR) operating at frequencies up to 100 GHz. The first version of the 5G standard was completed at the end of 2017, which allows for continued work on trials and commercial deployments of smartphones compliant with the 5G NR standard.

[0029] The overall system architecture assumes, among other things, an NG-RAN (Next Generation Radio Access Network) comprising gNBs, which provide the UE with NG radio access user plane (SDAP / PDCP / RLC / MAC / PHY) and control plane (RRC) protocol terminations. The gNBs are interconnected through the Xn interface. The gNBs are also connected to the NGC (Next Generation Core) through the Next Generation (NG) interface, more specifically, through the NG-C interface to AMF (Access and Mobility Management Function) (e.g., a specific core entity performing the AMF) and through the NG-U interface to UPF (User Plane Function) (e.g., a specific core entity performing the UPF). The NG-RAN architecture is shown in Figure 1 (see, e.g., 3GPP TS 38.300 v15.6.0, Chapter 4).

[0030] Various different deployment scenarios can be supported (see, e.g., 3GPP TR 38.801 v14.0.0). For example, non-centralized deployment scenarios are proposed (see, e.g., Chapter 5.2 of TR 38.801; centralized deployments are shown in Chapter 5.4), in which 5G NR-capable base stations can be deployed. Figure 2 An exemplary non-centralized deployment scenario is shown (see Figure 5 .2-1) while also showing LTE eNBs and user equipment (UEs) connected to both gNBs and LTE eNBs. A new eNB for NR 5G can be exemplarily referred to as gNB. An eLTE eNB is an evolution of an eNB that supports connectivity to both EPC (Evolved Packet Core) and NGC (Next Generation Core).

[0031] The user plane protocol stack for NR (see e.g. 3GPP TS 38.300, chapter 4.4.1) includes the PDCP (Packet Data Convergence Protocol, see chapter 6.4 of TS 38.300), RLC (Radio Link Control, see chapter 6.3 of TS 38.300) and MAC (Medium Access Control, see chapter 6.2 of TS 38.300) sub-layers, which terminate in the gNB on the network side. In addition, a new Access Stratum (AS) sub-layer (SDAP, Service Data Adaptation Protocol) is introduced on top of PDCP (see chapter 6.5 of TS 38.300). A control plane protocol stack is also defined for NR (see e.g. TS 38.300, chapter 4.4.2). An overview of the layer 2 functionality is given in subclause 6 of TS 38.300. The functionality of the PDCP, RLC and MAC sub-layers is listed in chapters 6.4, 6.3 and 6.2 of TS 38.300, respectively. The functionality of the RRC layer is listed in subclause 7 of TS 38.300.

[0032] For example, the medium access control layer handles logical channel multiplexing, as well as scheduling and scheduling-related functions, including handling different numerologies.

[0033] The physical layer (PHY) is, for example, responsible for coding, PHY HARQ processing, modulation, multi-antenna processing, and mapping of the signal to the 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 available for transmission of a particular transport channel, and each transport channel is mapped to a corresponding physical channel. One physical channel is the PRACH (Physical Random Access Channel) for random access.

[0034] Use cases / deployment scenarios for NR can include enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), 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 downlink and 10 Gbps for uplink) and user experience data rates, which are about three times what is offered by IMT-Advanced. On the other hand, in the case of URLLC, more stringent requirements are put on ultra-low latency (user plane latency of 0.5 ms for UL and DL) and high reliability (1-10 -5 -1 for 1 ms). Finally, mMTC preferably requires high connection density (1,000,000 devices / km 2 2 in urban environments), large coverage in bad environments and ultra-long battery life for low-cost devices (15 years).

[0035] Thus, the OFDM numerology (e.g., subcarrier spacing, OFDM symbol duration, cyclic prefix (CP) duration, number of symbols per scheduling interval) that is suitable for one use case can not be suitable for another use case. For example, a low latency service can prefer a shorter symbol duration (hence a larger subcarrier spacing) and / or fewer symbols per scheduling interval (also known as TTI) compared to an mMTC service. Furthermore, a deployment scenario with large channel delay spread can prefer a longer CP duration compared to a scenario with short delay spread. The subcarrier spacing should be optimized accordingly to keep similar CP overhead. NR can support more than one value of subcarrier spacing. Accordingly, subcarrier spacing of 15 kHz, 30 kHz, 60 kHz,... are currently under consideration. The symbol duration T u and the subcarrier spacing Af are directly related by the formula Af = 1 / T u Similar to in the LTE system, the term "resource element" can be used to denote the smallest resource unit consisting of one subcarrier for one OFDM / SC-FDMA symbol length.

[0036] In the new radio system 5G-NR, a resource grid of subcarriers and OFDM symbols is defined for each numerology and carrier, separately for uplink and downlink. Each element in the resource grid is called a resource element and is identified based on a frequency index in the frequency domain and a symbol position in the time domain (see 3GPP TS 38.211 v15.6.0).

[0037] Function split between NG-RAN and 5GC

[0038] Figure 3 The function split between NG-RAN and 5GC is shown. The NG-RAN logical nodes are gNB or ng-eNB. The 5GC has the logical nodes AMF, UPF and SMF.

[0039] In particular, the gNB and ng-eNB host the following main functions:

[0040] - Functions for radio resource management such as radio bearer control, radio admission control, connection mobility control, dynamic allocation of resources (scheduling) to UEs in both uplink and downlink;

[0041] - IP header compression, ciphering and data integrity protection;

[0042] - Selection of AMF at the UE attachment point when it is not possible to determine the routing to an AMF based on the information provided by the UE;

[0043] - Routing of user plane data to UPF;

[0044] - Control plane information routing to AMF;

[0045] - Connection establishment and release;

[0046] - Scheduling and transmitting paging messages;

[0047] - Scheduling and transmission of system broadcast information (originating from AMF or OAM);

[0048] - Configuration of measurement and measurement reporting for movement and scheduling;

[0049] -Transmission-level packet markings in the uplink;

[0050] -Session management;

[0051] -Supports network slicing;

[0052] - QoS flow management and mapping to data radio bearers;

[0053] - Supports UEs in the RRC_INACTIVE state;

[0054] -NAS message distribution functionality;

[0055] - Radio access network sharing;

[0056] -Biconnectivity;

[0057] -Close interoperability between NR and E-UTRA.

[0058] The Access and Mobility Management (AMF) function performs the following main functions:

[0059] -Non-Access Stratum (NAS) signaling terminal;

[0060] -NAS signaling security;

[0061] - Access layer AS security control;

[0062] - Inter-core network (CN) node signaling for mobility between 3GPP access networks; - Idle mode UE reachability (including control and paging retransmission execution);

[0063] -Registered area management;

[0064] -Supports mobility within and between systems;

[0065] -Access authentication;

[0066] - Access authorization, including roaming permission checks;

[0067] - Mobility management controls (subscriptions and policies);

[0068] -Supports network slicing;

[0069] - Session Management Function, SMF, selection.

[0070] In addition, the User Plane Function, UPF, hosts the following main functions:

[0071] - Anchor point for intra- / inter-RAT mobility (as applicable);

[0072] - External PDU session point of attachment to a data network;

[0073] - Packet routing and forwarding;

[0074] - User plane part of packet inspection and policy rule enforcement;

[0075] - Traffic usage reporting;

[0076] - Uplink classifier, supporting routing of traffic flows to a data network;

[0077] - Branch point for multi-homed PDU sessions;

[0078] - QoS handling for user plane, e.g., packet filtering, gating, UL / DL

[0079] - Uplink traffic verification (SDF to QoS flow mapping);

[0080] - Downlink packet buffering and downlink data notification triggering.

[0081] Finally, the Session Management Function, SMF, hosts the following main functions:

[0082] - Session management;

[0083] - UE IP address allocation and management;

[0084] - Selection and control of UP functions;

[0085] - Configuration of traffic steering at UPF to route traffic to the proper destination;

[0086] - Control part of policy enforcement and QoS;

[0087] - Downlink data notification.

[0088] RRC connection establishment and reconfiguration procedures

[0089] Figure 4 Some interactions between UE, gNB and AMF (5GC entities) are illustrated in the context of UE transition from RRC_IDLE to RRC_CONNECTED for the NAS part (see TS 38.300 v15.6.0).

[0090] RRC is a high layer signaling (protocol) used 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 along with the INITIAL CONTEXT SETUP REQUEST. The gNB then activates AS security with the UE, which is performed by the gNB sending a SecurityModeCommand message to the UE and by the UE responding to the gNB with a SecurityModeComplete message. Subsequently, the gNB performs reconfiguration to establish Signaling Radio Bearers 2 (SRB2) and Data Radio Bearers (DRBs) by sending an RRCReconfiguration message to the UE and receiving an RRCReconfigurationComplete from the UE in response by the gNB. For a signaling-only connection, the steps related to RRCReconfiguration are skipped as SRB2 and DRBs are not established. Finally, the gNB informs the AMF that the setup procedure has completed with an INITIAL CONTEXT SETUP RESPONSE.

[0091] Thus, in the present invention, there is provided an entity of a Fifth Generation Core (5GC) (e.g., AMF, SMF, etc.) comprising a control circuitry that establishes a Next Generation (NG) connection with a gNodeB, and a transmitter that transmits an initial context setup message to the gNodeB via the NG connection to establish a signaling radio bearer between the gNodeB (or gNB) and a user equipment (UE). Specifically, the gNodeB transmits, via the signaling radio bearer, a Radio Resource Control (RRC) signaling containing a resource allocation configuration information element to the UE. The UE then performs uplink transmission or downlink reception based on the resource allocation configuration.

[0092] Use scenarios for IMT in 2020 and beyond

[0093] Figure 5 Some use cases for 5G NR are shown. In the Third Generation Partnership Project New Radio (3GPP NR), three use cases are being considered, which are envisioned to support a wide range of services and applications through IMT-2020. The stage-1 specification for enhanced mobile broadband (eMBB) has been completed. In addition to further extending eMBB support, current and future work will also involve standardization for ultra-reliable low-latency communications (URLLC) and massive machine type communications. Figure 5 Some examples of the intended use scenarios for IMT in 2020 and beyond are shown.

[0094] URLLC use cases have stringent requirements on capabilities such as throughput, latency, and availability, and are 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. Ultra-reliability is supported for URLLC by identifying techniques that meet the requirements specified in TR 38.913. For Release 15 of NR URLLC, key requirements include a target user plane latency of 0.5 ms for UL (uplink) and 0.5 ms for DL (downlink). A general URLLC requirement for one packet transmission is a BLER (block error rate) of 1E-5 for a packet size of 32 bytes with a user plane latency of 1 ms.

[0095] From the perspective of RANI, reliability can be improved in a number of possible ways. The current scope for improving reliability involves defining separate CQI tables for URLLC, more compact DCI formats, repetition of PDCCH, etc. However, as NR becomes more stable and advanced (for NR URLCC key requirements), the scope for achieving ultra-reliability can expand. Specific use cases for NR URLCC in Rel. 15 include augmented reality / virtual reality (AR / VR), e-health, e-safety, and mission critical applications.

[0096] In addition, NR URLCC has technical enhancements for latency improvement and reliability improvement. Technical enhancements for latency improvement include configurable numerology, non-slot-based scheduling with flexible mapping, grant-free (configured grant) uplink, slot-level repetition for data channels, and downlink pre-emption. Pre-emption means stopping a transmission of an already allocated resource, and the already allocated resource is used for another transmission that is requested later but has lower latency / higher priority requirements. Thus, an already granted transmission is pre-empted by a later transmission. Pre-emption applies to transmissions independent of a specific service type. For example, a transmission of service type A (URLCC) can be pre-empted by a transmission of service type B (such as eMBB). Technical enhancements for reliability improvement include dedicated CQI / MCS tables for a target BLER of 1E-5.

[0097] Use cases for mMTC (massive machine type communications) are characterized by a large number of connected devices that typically transmit relatively low capacity non-delay sensitive data. The devices require low cost and long battery life. From the perspective of NR, utilizing very narrow bandwidth parts is one possible solution to achieve energy saving and prolong battery life from the UE perspective.

[0098] As mentioned above, the range of reliability for NR is expected to be expanded. One key requirement in all cases, and especially for URLLC and mMTC, is high reliability or ultra-reliability. From a radio perspective and network perspective, several mechanisms can be considered to improve reliability. In general, there are some potential areas that help improve reliability. These areas include compact control channel information, data / control channel repetition, and diversity in frequency, time, and / or spatial domain. These areas are generally applicable to reliability regardless of the specific communication scenario.

[0099] For NR URLLC, more use cases have been identified that require more stringent requirements, such as factory automation, transportation, and power distribution, including factory automation, transportation, and power distribution. The more stringent requirements are higher reliability (up to 10-6 order), higher availability, packet size up to 256 bytes, time synchronization down to a few μm (where the value can be one or a few μm depending on the frequency range), short latency of 0.5 to 1 ms, and in particular target user plane latency of 0.5 milliseconds depending on the use case.

[0100] In addition, for NR URLCC, several technical enhancements have been identified from the perspective of RANI. Among them are PDCCH (Physical Downlink Control Channel) enhancements related to compact DCI, PDCCH repetition, 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 mini-slot level frequency hopping and retransmission / repetition enhancements are also identified. The term "mini-slot" refers to a transmission time interval (TTI) that includes a smaller number of symbols than a slot (including a slot of 14 or 12 symbols).

[0101] In slot-based scheduling or assignment, a slot corresponds to the timing granularity for scheduling assignment (TTI - Transmission Time Interval). Typically, the TTI determines the timing granularity for scheduling assignment. One TTI is the time interval for which a given signal is mapped to the physical layer. For example, traditionally, the TTI length can vary from 14 symbols (slot-based scheduling) to 2 symbols (non-slot-based scheduling). Downlink (DL) and uplink (UL) transmissions are specified to be organized into frames (10 ms duration) composed of 10 subframes (1 ms duration). In slot-based transmission, a subframe is further divided into slots, the number of which is defined by the numerology / subcarrier spacing. The specified value ranges between 10 slots per frame (1 slot per subframe) for a subcarrier spacing of 15 kHz to 80 slots per frame (8 slots per subframe) for a subcarrier spacing of 120 kHz. The number of OFDM symbols per slot is 14 for a normal cyclic prefix and 12 for an extended cyclic prefix (see sections 4.1 (general frame structure), 4.2 (Numerologies), 4.3.1 (frames and subframes), and 4.3.2 (slots) of 3GPP TS 38.211 V15.3.0, Physical channels and modulation, 2018-09). However, the assignment of time resources for transmission can also be non-slot-based. Specifically, the TTI in non-slot-based assignment can correspond to a mini-slot rather than a slot. That is, one or more mini-slots can be assigned for a requested transmission of data / control signaling. In non-slot-based assignment, the minimum length of a TTI can be, for example, 1 or 2 OFDM symbols.

[0102] QoS control

[0103] The 5G QoS (Quality of Service) model is based on QoS Flows, and supports QoS Flows that require guaranteed flow bit rates (GBR QoS Flows) and QoS Flows that do not require guaranteed flow bit rates (non-GBR QoS Flows). Therefore, at the NAS level, the QoS Flow is the finest granularity of QoS differentiation in a PDU Session. A QoS Flow is identified in a PDU Session by a QoS Flow ID (QFI) carried in encapsulation headers over the NG-U interface.

[0104] 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 a PDU Session, and can subsequently configure additional DRBs for QoS Flows of that PDU Session (depending on when the NG-RAN does so), e.g., as referenced above with respect to Figure 4The 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.

[0105] Figure 6 A 5G NR non-roaming reference architecture is shown (see TS 23.501 v16.1.0, chapter 4.23). Application Functions (AFs) (e.g., external application servers of the 5G service examples described in chapter 2.2.2) interact with the 3GPP core network to provide services, e.g., to support application influence 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 operator deployment, operator considers trusted application functions can directly interact with the relevant network functions. Operator does not allow application functions that have direct access to network functions to interact with the relevant network functions via the NEF using the external exposure framework. Figure 5

[0106] Figure 6 Further functional units of the 5G architecture are shown, 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), e.g., operator services, Internet access, or third-party services.

[0107] A terminal or user terminal, or user equipment, is referred to as user equipment (UE) in LTE and NR. This can be a mobile device, such as a wireless phone, smartphone, tablet, or USB (Universal Serial Bus) stick with user equipment functionality. However, the term mobile device is not limited to this, in general, a relay can also have the functionality of such a mobile device, and a mobile device can also be used as a relay.

[0108] A base station is a network node, e.g., forming part of a network for providing services to terminals. A base station is a network node or scheduling node that provides wireless access to terminals. Communication between terminals and base stations is typically standardized. In LTE and NR, the wireless interface protocol stack comprises a physical layer, a medium access layer (MAC), and higher layers. In the control plane, a radio resource control protocol of higher layers is provided. Via RRC, a base station can control the configuration of a terminal, and a terminal can communicate with a base station to perform control tasks such as connection and bearer setup, modification, and measurement, and other functions. The term used in LTE is eNB (or eNodeB), while the current 5G NR term is gNB

[0109] ​Services that transport data provided by a layer to a higher layer are often referred to as channels. For example, LTE and NR distinguish between logical channels provided by the MAC layer to higher layers, transport channels provided by the physical layer to the MAC layer, and physical channels that define the mapping on the physical resources.

[0110] Logical channels are different types of data transport services provided by the MAC. Each logical channel type is defined by the type of information transferred. Logical channels are divided into two groups: control channels and traffic channels. Control channels are only used for the transfer of control plane information. Traffic channels are only used for the transfer of user plane information.

[0111] The MAC layer then maps the logical channels onto transport channels. For example, logical traffic channels and some logical control channels can be mapped onto a transport channel in the downlink called the downlink shared channel, DL-SCH, and in the uplink called the uplink shared channel, UL-SCH.

[0112] Downlink control channel monitoring, PDCCH, DCI

[0113] Many functions operated by a UE involve monitoring of a downlink control channel (e.g., PDCCH, see 3GPP TS 38.300 v15.6.0, chapter 5.2.3) to receive, for example, specific control information or data sent to the UE.

[0114] As mentioned above, PDCCH monitoring is done by the UE in order to identify and receive information intended for the UE, such as control information as well as user traffic (e.g., DCI on PDCCH, and user data on PDSCH indicated by PDCCH).

[0115] Control information in the downlink (which can be referred to as downlink control information, DCI) has the same purpose in 5G NR as in LTE, i.e., is a special set of control information that, for example, schedules a downlink data channel (e.g., PDSCH) or an uplink data channel (e.g., PUSCH). In 5G NR, many different DCI formats have been defined (see TS 38.212 v15.6.0 chapter 7.3.1).

[0116] PDCCH monitoring for each of these functions has a specific purpose, and thus starts from this purpose. PDCCH monitoring is often controlled based on at least a timer operated by the UE. The timer has the purpose of controlling the PDCCH monitoring, for example, to limit the maximum amount of time the UE monitors PDCCH. For example, the UE can not need to monitor PDCCH indefinitely, but can stop monitoring after some time in order to be able to save power.

[0117] As mentioned above, one of the purposes of the DCI on the PDCCH is to dynamically schedule resources in the downlink or uplink or even sidelink. In particular, some DCI formats are provided to carry an indication of the resources (resource allocation, RA) allocated to a specific user's data channel. The resource allocation can include a specification of resources in the frequency domain and / or time domain.

[0118] Resource allocation

[0119] In the time domain, the scheduling timing (e.g., for the scheduling of the above-mentioned resources) can be indicated within the DCI by using a time domain resource allocation (TDRA) table, as specified, e.g., in Release 15 (NR). In particular, the UE can be informed of the resources allocated in the time domain by indicating one entry (row) of the TDRA table in the DCI, e.g., by signaling the entry (row) index. The term table is used as a logical term herein, as for NR, the TDRA entries are summarized as a table in the standard specification.

[0120] Repetition on PDSCH and PUSCH

[0121] Transmissions in NR can include a self-initiated (i.e., not triggered by (H)ARQ) repetition of data. In this case, the same data (e.g., transport block) is transmitted N times, N being an integer greater than 1. The number of repetitions can be configured.

[0122] Multiple transmission / reception points, TRPs

[0123] The physical layer in NR can provide multi-antenna operation, such as MIMO (Multiple Input, Multiple Output), which can, e.g., include the use of multiple or multiple transmission and reception points (multiple TRPs). For example, a user equipment can receive data from multiple TRPs (transmission and reception points), where the multiple TRPs 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 for multi-TRP communication or transmission.

[0124] The techniques described in this disclosure are not limited to a particular arrangement of TRPs or a particular relationship between the TRPs and the gNB. Thus, for example, multi-TRP operation can be performed by a gNB having different antenna panels or radio heads corresponding to the TRPs and different radio frequency units operated using the respective antennas.

[0125] Furthermore, in multi-TRP, with respect to the location relationship between the TRPs, several options can be envisaged, and the distance between two TRPs can vary. For example, the TRPs can be close, such that a UE receives signals from these TRPs from similar angles. However, the TRPs can also be located quite far from each other, e.g. at remote locations of a network cell. A UE served by two TRPs can receive and transmit signaling from the respective TRPs on uncorrelated channels. Thus, the gain in channel diversity can be best exploited.

[0126] For example, multi-TRP can be classified into two high-level categories. Namely, the categories can be classified with respect to the backhaul type of the backhaul link between two given TRPs.

[0127] On the one hand, an ideal backhaul is a very high throughput and very low latency backhaul, such as using a dedicated point-to-point connection, e.g. optical fiber. Assuming an ideal backhaul allows for communication between the TRPs with a delay of about or almost 0ms (e.g. for LTE-A, less than 2.5us one-way latency is mentioned in section 6.1 of technical report 3GPP TR 36.932 V15.0.0 (2018-06), however excluding the propagation delay in the optical fiber / cable).

[0128] On the other hand, a non-ideal backhaul is a backhaul such as DSL, microwave and other similar relays, and can for example involve a finite (one-way) delay in the range of 2ms or 5ms for communication between two given TRPs.

[0129] In addition to the classification into ideal backhaul and non-ideal backhaul, further classification can be made in multi-TRP MIMO techniques with respect to how the (central) baseband units are shared between the TRPs.

[0130] For example, although each of the two given TRPs has a different RF (radio frequency) unit, the TRPs can share the same baseband unit. Therein, the link between the RF unit and the baseband unit can be ideal or non-ideal. Alternatively, there can be both a different (central) baseband unit and a different RF unit for each TRP. Therein, the respective links between the baseband units and the RF units as well as the links between the different baseband units can be ideal or non-ideal.

[0131] The present invention relates to time domain resource allocation for transmission from multiple TRPs, in particular PDSCH repetition. Typically, using single-DCI based scheduling from one of the TRPs, repetitions of PDSCH from multiple TRPs can be scheduled.

[0132] Figure 11An example of such PDSCH repetition is shown in FIG. 2. As can be seen, a single DCI (PDCCH) from TRP 1 is scheduling 5 times of PDSCH repetition. More specifically, three times of PDSCH repetition (i.e., the first, second, and fourth repetition) are scheduled from TRP 1, and two times of PDSCH repetition (i.e., the third repetition and the fifth repetition) are scheduled from TRP 2. Both inter-slot and intra-slot repetition are supported, and ideal backhaul is considered among multiple TRPs.

[0133] Note that each TRP can be associated with a separate TCI state, and TCI state and TRP can be used interchangeably. Specifically, in the following, TCI state 1 can be referred to as TRP 1, and TCI state 2 can be referred to as TRP 2, and so on.

[0134] However, when scheduling multiple TRPs, there are several issues with scheduling and associating repetitions. More specifically, in order to schedule repetitions of PDSCH from multiple TRPs by a single DCI from one of the TRPs, the following are open issues for time domain resource allocation:

[0135] First, the UE must be indicated which repetitions are associated with which TRPs. For example, Figure 12 The UE in FIG. 1 must know that TRP 1 transmits the first, second, and fourth repetitions, and TRP 2 transmits the third and fifth repetitions.

[0136] Second, the UE must be indicated the time domain resources of each repetition. For example, Figure 12 The UE in FIG. 1 must know the starting symbol, slot, and length of each of the five repetitions.

[0137] Third, the UE must be indicated the number of transmissions to be scheduled from each TRP and the combined total number of transmissions from all TRPs. For example, Figure 12 The UE in FIG. 1 must know that the total number of transmissions to be scheduled is five, with three from TRP 1 and two from TRP 2.

[0138] In general, semi-static or dynamic indication to the UE about the association of repetitions with one of the TRPs is possible. For semi-static association, some patterns of which repetitions are associated with which TRP on can be fixed. However, depending on the availability of TRPs and / or corresponding time domain resources, such an approach can not provide sufficient flexibility to apply the association.

[0139] Dynamic association is available with DCI indication. However, if explicit indication in the form of a bitmap is used, the size of the bitmap can increase proportionally with the number of repetitions and / or TRPs.

[0140] Figure 7An exemplary UE according to an embodiment is shown. According to an embodiment, a user equipment 760 (UE) is provided that includes a transceiver 770. The transceiver 770 receives downlink control information, DCI, signaling. The UE can also include a processor (or processing circuitry) 780 that obtains, from the DCI signaling, a transmission configuration indication, TCI, indicator that specifies that two or more TCI states are configured. In addition, the processor 780 can obtain an indication of time domain resources for transmission and an association of the time domain resources to the two or more TCI states. Advantageously, each time domain resource is associated with one of the two or more TCI states. The transceiver can also receive or transmit data on the time domain resources associated with each of the two or more TCI states.

[0141] The circuitry 780 can implement more functionality than the above-described determination of time domain resources for transmission / reception using multiple TRPs. Thus, the circuitry 780 is considered to include time domain resource determination circuitry 785 configured to perform the time domain resource determination. The configuration can be provided by hardware adaptation and / or software.

[0142] Figure 8 A functional structure of the time domain resource determination circuitry 785 is shown. In particular, the time domain resource determination circuitry 785 includes PDCCH processing circuitry 870 that obtains, from the DCI, the TCI indicator and an indication of time domain resources for transmission and an association of the time domain resources to respective TCI states. The time domain resource determination circuitry 785 also includes resource determination circuitry 880 that, when the TCI indicator indicates two or more TCI states, determines, based on the time domain resource indication, an allocation of time domain resources for the respective TCI states. The processing circuitry 780 can then control the transceiver 770 to receive or transmit data on the determined resources.

[0143] According to another embodiment, a base station 710 (scheduling node) is provided that includes a processor 730. The processor 730 generates downlink control information, DCI, signaling that indicates a transmission configuration indication, TCI, indicator that specifies that two or more TCI states are configured. The TCI signaling also indicates time domain resources for transmission and an association of the time domain resources to the two or more TCI states, where each time domain resource is associated with one of the two or more TCI states. The base station also includes a transceiver 720 that transmits the DCI signaling. The transceiver also receives or transmits (e.g., to a UE 760) data on the time domain resources associated with each of the two or more TCI states. Similar to the processor 780 in the UE, the processor 730 can also perform various different tasks. Time domain resource allocation circuitry 735 is represented here as a functional part of the processor 730 that performs the above-described time domain allocation tasks, including determining the resources and providing corresponding signaling to the UE 760.

[0144] As part of the circuitry 730, the scheduling device can further include allocation circuitry that performs scheduling of one or multiple UEs. As a result of the scheduling, time domain resource allocation is generated and corresponding DCI signaling is generated, indicating TCI indicators and resource allocation and association of resources with TCI states. The circuitry then controls the transceiver 720 to transmit or receive data in the scheduled resources of the one or multiple UEs.

[0145] An exemplary functional structure of the time domain resource allocation circuitry 735 is shown in Figure 9 Specifically, the time domain resource allocation circuitry 735 can include scheduling circuitry 936 and PDCCH generation circuitry 937. The scheduling circuitry 920 performs scheduling, e.g., collects measurements from one or multiple UEs, and allocates resources in time domain (and possibly also in frequency domain and TRPs) to the respective UEs based on requests from the UEs and / or availability of their resources. The PDCCH generation circuitry 930 then generates DCI including TCI indicators and resource allocation and association of time domain resources with TCI states according to the scheduling results for the respective one or multiple UEs.

[0146] As shown in Figure 7 The UE 760 and the scheduling node 710 can form a communication system, i.e., be capable of communicating over the channel 750.

[0147] Generally, the DCI signaling can be one bit field of a single DCI (e.g., a time domain resource allocation (TDRA) field). The DCI signaling can be configured to indicate time domain resources of a first data transmission (e.g., a first transmission indicated by the DCI signaling) and an association of the time domain resources of the first data transmission with one of two or more TCI states. The DCI signaling can further indicate time domain resources of further data transmissions (e.g., repetitions of the first data transmission) and each association of them with one of the two or more TCI states. In other words, the bit field of the DCI signaling can collectively indicate time domain resources of multiple (e.g., two or more) transmissions and an association of the time domain resources with two or more TCI states.

[0148] Note that the further data transmissions can be associated with the same or different TCI states as the TCI state associated with the first data transmission. In other words, the two or more transmissions can be associated with the same or different TCI states of the two or more TCI states.

[0149] Furthermore, generally, there can be no configured TCI state associated with the time domain resources (of the time domain resources indicated by the DCI signaling). However, advantageously, there are two or more configured TCI states associated with the time domain resources. In other words, advantageously, two or more time domain resources are associated with (mutually) different TCI states.

[0150] Furthermore, advantageously, each of the time domain resources can be associated with a single TCI state of the two or more TCI states. In other words, the indication / DCI signaling can indicate for each time domain resource only a single association of the time domain resource with a single TCI state of the two or more TCI states.

[0151] It should also be noted that, generally, the further transmission can be a repetition, i.e., a transmission of the same transport block (TB) as the first transmission. However, the present application is not limited thereto, and the further transmission can be a transmission of a different TB than the first transmission. In other words, the present application can be applied directly (and in the same way) to identical repetitions as well as to transmissions of different TBs. Thus, generally, the TBs of all transmissions can be mutually different; the TBs of some transmissions can be mutually different, while the TBs of other transmissions are identical; or the TBs of all (first and further) transmissions can be identical. Thus, generally, the two terms “transmission” and “repetition” can be used interchangeably.

[0152] It should also be noted that the present application is applicable to an arbitrary number of transmission reception points (TRPs) and / or to an arbitrary number of TCI states. In other words, the examples explicitly described below refer to a simple case of only two TRPs / TCI states for simplicity only. It should also be noted that each TRP can be associated / correspond to a respective TCI state and vice versa, so that the terms “TRP” and “TCI state” can be used interchangeably in the present application.

[0153] Generally, the processor can obtain the TCI indicator and the indication by parsing the DCI signaling based on, e.g., a syntax and semantics that can be at least partially configurable by the network.

[0154] In particular, the total number of repetitions for all TRPs, the number of TCI states (TRPs) actually used for the transmission, and / or the association of each time domain resource with one of the indicated TCI states, the total number of transmissions associated with each indicated TCI state, the number of TCI states (TRPs) actually used for the transmission, and / or the one bit field of the single DCI for each transmission can be explicitly indicated or determined based on an implicit indication.

[0155] In some embodiments, the indication obtained by the UE from the DCI signaling is an index indicating an entry of a time domain resource assignment (TDRA) table.

[0156] Generally, an entry of a TDRA table generally corresponds to a row of the TDRA table. However, any other definition of an entry of a TDRA table can also be used, e.g., an entry in a column. The DCI signaling can comprise an indication of a DCI index (also referred to as DCI index in the following). In other words, generally, the DCI signaling can indicate an entry of a TDRA table by indicating an index of the respective row / column. Generally, this DCI index can be indicated / signaled in the DCI signaling by a codepoint. Note that in the following, the terms “row” and “entry” of a TDRA can be used interchangeably.

[0157] Further, generally, a UE can be configured with more than one TDRA table. The usage of a TDRA table will be synchronized with the base station, e.g., the base station will signal to the UE which TDRA table to apply. Alternatively, in some scenarios, the UE and the base station can implicitly derive in the same way which TDRA table to use based on other parameters known to both.

[0158] Generally, the more explicit the information, the higher the flexibility of resource allocation and associated, but potentially also the larger the signaling overhead.

[0159] In some embodiments, an entry of a TDRA table comprises two or more sets of start and length indicator values, SLIVs. Advantageously, each set corresponds to a respective TCI state, and each SLIV corresponds to a respective transmission and indicates a start position and a length of a time domain resource for the respective transmission. The time domain resource for the respective transmission can be associated with the TCI state corresponding to the set of SLIVs (e.g., the SLIVs indicating the time domain resource thereof).

[0160] Generally, an entry of a TDRA table can comprise or indicate one or more SLIV values. For example, a SLIV indicates or specifies a time domain resource by indicating / specifying a start position and a length of the time domain resource. In particular, a SLIV can correspond to an ordered pair of two numbers (in particular, integers), where one indicates a start position of a time domain resource and the other indicates a length of the time domain resource. Generally, a SLIV can indicate a time domain resource for a single transmission / repetition, and each time domain resource for a transmission / repetition can be indicated by a single SLIV.

[0161] Generally, each SLIV in the TDRA table can be associated with or correspond to a respective TCI state. In particular, each SLIV can correspond to only a single TCI state. On the other hand, an entry can indicate zero, one or multiple SLIVs of one TCI state. In other words, for each TCI state of two or more TCI states (e.g., configured TCI states), an entry can include or indicate a set of SLIVs. However, each SLIV can be in only a single group of SLIVs, also referred to herein as “the” group of SLIVs. These sets can be empty, can include only one SLIV, or can include multiple SLIVs. Then, the time-domain resources indicated by the SLIVs are associated with the same TCI state as the respective SLIV (i.e., the SLIV indicating the time-domain resources).

[0162] In this regard, it is further noted that the terms “group”, “set” and “grouping” of SLIVs are used interchangeably.

[0163] It is noted that an entry of a TDRA can generally also include or indicate a physical downlink shared channel (PDSCH) mapping type, and e.g., a K2 value. The K2 value indicates a slot offset of a starting position indicated by the SLIVs of the same TDRA entry. It is noted that for the present disclosure, the indication of the PDSCH mapping type and the signaling of the slot offset K2 is not necessary. The slot offset can be relative to the slot of the DCI signaling indicating the entry of the TDRA table. Further, for inter-slot repetition, one or more entries of the TDRA table can include multiple values of K2.

[0164] An example of a TDRA table according to the present embodiment is shown in the following TDRA table 1.

[0165] TDRA table 1

[0166]

[0167] It can be seen that for each value of the DCI index, the TDRA table 1 indicates two groups of time-domain resources (SLIVs), more specifically, the fourth list indicates SLIV group 1 and the fifth list indicates SLIV group 2. However, generally, a TDRA table can indicate more than two groups of SLIVs for each value of the DCI index.

[0168] It can be seen that in the TDRA table 1, each group is associated with one TCI state. More specifically, in the present example, SLIV group 1 corresponds to TCI state 1 and SLIV group 2 corresponds to TCI state 2. Generally, a TDRA table can indicate more groups, each of which is associated with a TCI state. Generally, these groups can correspond to mutually different TCI states. However, the present disclosure is not limited thereto and some groups can be associated with the same TCI state.

[0169] Generally, each group can have multiple time domain resources (SLIVs) which correspond to all repetitions associated with the respective TCI state. However, the present application is not limited thereto and some groups can comprise zero or only a single SLIV.

[0170] In the example shown in TDRA table 1, the DCI index value 0 indicates two SLIVs of SLIV group 1, namely SLIV1-0-1 and SLIV1-0-2, and two SLIVs of SLIV group 2, namely SLIV2-0-1 and SLIV2-0-2. On the other hand, the DCI index value 1 indicates two SLIVs of SLIV group 1, namely SLIV1-1-1 and SLIV1-1-2, but only one SLIV of SLIV group 2, namely SLIV2-1-2. Thus, in general, there can be an arbitrary number of SLIVs in each SLIV group, independent of the number of SLIVs in other SLIV groups and / or SLIV groups of other DCI indices. In particular, the number of SLIVs in a SLIV group can be zero.

[0171] Generally, based on the TDRA table of general form TDRA table 1 and the indices indicated in the DCI (or, in other words, based on the entries shown in TDRA table 1), the time domain resources for each repetition can be determined as follows: Each SLIV is mapped one-to-one to each repetition in order to determine the starting symbol and length within the slot with offset K2 from the scheduling PDCCH (e.g., from the slot in which the DCI signaling indicating the entry with said offset K2 is signaled). The order of the SLIVs of all groups is determined by the increasing order of their starting symbol values.

[0172] Furthermore, based on the TDRA table 1 (in particular, based on the entries of said TDRA table indicated by the DCI indices indicated in the DCI signaling), the association of each repetition with one of the indicated / configured TCI states is determined based on the group. More specifically, based on the SLIV group, each repetition (or each time domain resource) is associated with one of the indicated TRPs / TCI states.

[0173] If there is one group but no SLIV is indicated within that group, it means that no transmission from a TRP is associated with that group. For example, in TDRA table 1, for SLIV group 2 and DCI index = 15, no SLIV is indicated.

[0174] Further, based on the TDRA table 1, the total number of repetitions associated with each configured TCI state can be determined by the number of SLIVs within a given group. In other words, for each entry, the total number of repetitions associated with a TCI state can be determined by counting the SLIVs in the TCI group of the entry. For example, in the TDRA table 1, for the SLIV group 2, the total number of repetitions for DCI indexes 0, 1, 2, and 15 are 2, 1, 2, and 0, respectively. Further, based on the TDRA table, the number of TCI states (or TRPs) actually used for transmission can be determined by the number of groups with at least one indicated SLIV within the entry indicated by the DCI index. In other words, for a given entry, the number of TCI states actually used can be determined by counting the TCI groups of the entry with at least one specified SLIV.

[0175] Further, according to the TDRA table 1, the total number of repetitions for all TRPs can be determined by the total number of SLIVs across all groups. For example, in the TDRA table 1, the total number of repetitions for DCI indexes 0, 1, 2, and 15 are 4, 3, 3, and 2, respectively.

[0176] A more explicit example of the TDRA table 1 according to the present embodiment is shown in the following TDRA table 2.

[0177] TDRA table 2

[0178]

[0179] If the DCI index 0 of the TDRA table 2 is indicated to the UE, the time domain resource allocation and the association with TRPs would be as shown in Figure 12 .

[0180] In particular, the slot offset for starting the transmission is “1” slot after the DCI signaling (scheduling PDCCH). More specifically, the slot offset “1” means that the starting position of the time domain resource indicated by the SLIV is specified with respect to the first slot after the DCI signaling. Here, generally, the “DCI” signaling refers to the DCI signaling indicating the entry with the slot offset.

[0181] It can be seen that SLIV group 1 has 3 SLIVs, namely "{0, 3}", "{4, 2}", "{12, 2}"; and for SLIV group 2, there is 1 SLIV, namely "{8, 4}", where each SLIV is expressed in the general form "{start position of time domain resources, length of time domain resources}". Thus, based on the start symbol index of the SLIV in the first entry of the TDRA table 2 (corresponding to the second row in the TDRA table 2, DCI index 0, which is the convention adopted henceforth), the repetition order is "{0, 3}", "{4, 2}", "{8, 4}", "{12, 2}". Thus, there are 4 repetitions in total for TRP1 (TCI state 1) and TRP2 (TCI state 2).

[0182] Further, based on the grouping shown in the table, the 1st, 2nd, and 4th repetitions are associated with TCI state 1, and thus come from TRP 1; and the 3rd repetition is associated with TCI state 2, and thus comes from TRP 2. Thus, there are 3 repetitions for TRP1 and 1 repetition for TRP2.

[0183] All of this is also shown in Figure 12 . In particular, the time domain resources for the 1st transmission / repetition are the first 3 symbols (e.g., with indices 0, 1, and 2) of TRP1 in the first slot after the DCI signaling. The time domain resources for the 2nd repetition are the symbols with indices 4 and 5 of TRP1 in the first slot after the DCI signaling. The time domain resources for the 3rd repetition are the symbols with indices 8, 9, 10, and 11 of TRP2 in the first slot after the DCI signaling, and the time domain resources for the 4th repetition are the symbols with indices 12 and 13 of TRP1 in the first slot after the DCI signaling.

[0184] This embodiment (e.g., the TDRA table in the form of TDRA table 2) provides full flexibility to have any particular SLIV value for each transmission, any order of TCI state association, and to assign unequal number of repetitions to different TCI states.

[0185] In example implementations, each set includes no more than one SLIV, and an entry of the TDRA table includes an indication of the total number of transmissions (e.g., the total number of transmissions explicitly or implicitly scheduled / indicated by that entry).

[0186] In these embodiments, each group has at most a single time domain resource (SLIV) corresponding to the 1st transmission associated with the respective TCI state. Further, each entry of the TDRA table can indicate the total number of repetitions. Here, the total number of transmissions indicates the total number of transmissions scheduled by that entry of the TDRA table (the entry that also indicates said total number).

[0187] Note that the total number of SLIVs indicated by an entry (e.g., by an entry of TDRA table 2) already implicitly indicates the total number of transmissions. This implicit number can be obtained by simply counting the explicitly indicated SLIVs. However, an entry can explicitly and / or separately from the aforementioned implicit indication indicate the total number of transmissions by the number of SLIVs. Thus, in general, the total number of transmissions indicated by an entry can differ from (e.g., be greater than) the total number of SLIVs explicitly indicated by the entry. Thus, such an entry implicitly indicates the existence of transmissions in addition to the transmissions explicitly indicated by the SLIVs of the entry.

[0188] In some embodiments, the processor of the UE determines, for each set comprising one SLIV, a start position and a length of time domain resources of a respective first transmission of the set (e.g., of a first transmission with a TCI state corresponding to the set) in accordance with the SLIV comprised in the set (i.e., the one SLIV). Alternatively or additionally, the processor can determine, for each transmission that is not one of the first transmissions: i) an association of time domain resources for the transmission to one of two or more TCI states in accordance with a pattern, the pattern indicating a sequence of TCI states and corresponding to the start position of the time domain resources for the first transmission; ii) a length of time domain resources for the transmission in accordance with a length of time domain resources of a respective first transmission (indicating a first transmission of the transmissions with the same TCI state as the respective transmission), wherein the time domain resources for the respective first transmission and the time domain resources for the transmission are associated with the same TCI state; and / or iii) a start position of the time domain resources for the transmission in accordance with: an offset, a start position, and a length of time domain resources of a transmission preceding the transmission. Here, the offset can correspond to (or be determined from / based on) the start position and / or the length of time domain resources for at least two first transmissions.

[0189] The above determination process will be explained with reference to TDRA table 3.

[0190] TDRA table 3

[0191]

[0192]

[0193] It can be seen that the sixth column in TDRA table 3 (explicitly) indicates the total number of repetitions. In general, a TDRA can comprise a separate column (not necessarily the sixth column) that (explicitly) indicates the total number of repetitions. Based on such a table, the total number of repetitions for all TRPs / TCI states can thus be determined from the explicit indication in said separate column. More generally, an entry of a TDRA table can indicate / comprise the total number of repetitions for all TRPs / TCI states, and thus, said total number can be determined from the explicit indication.

[0194] Generally, the number of TRPs / TCI states actually used for transmission based on a TDRA table 3 in general form and the indicated DCI index (or, in other words, based on an entry shown in TDRA table 3) can be determined by the number of SLIV groups within the entry (e.g., the entry indicated by the DCI) where at least one SLIV is indicated for the group. In other words, for a given entry, the number of TCI states actually used can be determined by counting the TCI groups of the entry with at least one specified SLIV.

[0195] In terms of time domain resources, for each TCI group, at most one SLIV can be indicated, which corresponds to the starting symbol and length of the first repetition from the associated TRP. For the first repetition, the time domain resources are associated with the TCI states of the TCI group whose SLIV explicitly specifies the time domain resources.

[0196] Further / next repetitions for which the time domain resources are not explicitly specified in the TDRA entry exist if the total number of transmissions is larger than the number of TCI states actually used. Here, the number of these further / next transmissions can correspond to the “total number of transmissions” minus the “number of TCI states actually used”.

[0197] The association of these further repetitions can be determined by distributing them (e.g., uniformly) according to a pattern on the actually used TCI states (e.g., the TCI states for which the first repetition is specified in the respective TDRA entry). The pattern can be predetermined, semi-static, and / or RRC configured. For example, each of the further repetitions can be associated with a further TCI state. Alternatively or additionally, the next repetitions can be associated with the actually used TCI states in a cyclic manner (e.g., based on the order of the TCI states of the first repetition). For example, the order of the first repetition can be repeated cyclically. Generally, the pattern can be predetermined or can be derived from the SLIV of the first repetition, in particular from the order of the TCI states of the first repetition. Generally, such a pattern represents a sequence of the configured TCI states.

[0198] The starting position (also referred to as starting symbol) of the time domain resources (SLIV) of the next repetitions is determined as follows. For example, the starting symbol of each repetition can be determined by a symbol offset between the starting symbol and / or the ending symbol of the SLIVs from different SLIV groups. Alternatively, the offset value can be predetermined, semi-static, and / or RRC configured. For example, the offset can be set to 1, which corresponds to a consecutive allocation of resources.

[0199] The symbol offset can be computed from the indicated SLIVs, in particular by subtracting the starting / ending position of the time domain resources explicitly indicated by two (different) SLIVs (the ending position can be the starting position plus the length).

[0200] The symbol offset can then be added to the start / end position of the time domain resource of the first repetition to obtain the start / end position of the time domain resource of the subsequent (e.g., consecutive) repetition. It should also be noted that in general, the time domain resource of all subsequent transmissions can be determined based on the same symbol offset. Alternatively, a different symbol offset can be used for each subsequent repetition.

[0201] The length of the time domain resource of the subsequent / further repetition (e.g., not the first repetition) can be based on the length of the time domain resource of the first repetition. In particular, the length of the subsequent transmission can be based on the length of the first transmission in the same group as the subsequent transmission. For example, the length of the subsequent repetition can be the same as the length of the corresponding first repetition of the corresponding group.

[0202] Further, the total number of repetitions associated with each configured TCI state can be determined by dividing the explicitly specified total number of repetitions by the number of TCI states actually used for transmission. Alternatively, for each entry, the total number of repetitions associated with the TCI state can be determined by calculating the SLIV in the TCI group of the entry.

[0203] This design option has less flexibility, but requires smaller table size and lower DCI overhead to indicate the rows of the table.

[0204] A more explicit example of TDRA Table 3 according to the present embodiment is shown in TDRA Table 4.

[0205] TDRA Table 4

[0206]

[0207] If the DCI index 0 of TDRA Table 4 is indicated to the UE, the time domain resource allocation and association with TRPs will be as shown in Figure 13 corresponding to intra-slot scheduling.

[0208] In particular, K2 in the first entry is indicated as “1”, thus the slot offset for starting the transmission is “1” slot after the scheduling PDCCH. Based on SLIV1, “{0, 3}”, the first repetition from TRP1 will start from symbol #0, spanning 3 symbols. In other words, the time domain resource of the first repetition is the symbols with index #0, #1 and #2. Further, based on SLIV2, “{5, 3}”, the first repetition from TRP2 (overall second repetition) will start from symbol #5, spanning 3 symbols (i.e., symbols #5, #6 and #7). The symbol offset between the repetitions is calculated as 3 (the difference between the first symbol index #5 of SLIV 2 and the last symbol index #3 of SLIV 1).

[0209] Since the total number of repetitions is indicated as “3”, there is one subsequent repetition (the third repetition overall). In this example, since the association of repetitions follows an alternating pattern, and the second repetition is from TRP 2, the third repetition will be from TRP 1. Furthermore, based on the symbol offset of “3” and the index of the last symbol of the second repetition of “7”, the index of the starting symbol of the third repetition will be #10. The length of the third repetition will be the same as the length of the first repetition, since the first repetition uses the same TRP as the third repetition. Thus, the third repetition will span 3 symbols (i.e., symbols #10, #11, and #12).

[0210] Another explicit example of TDRA table 3 according to the present embodiment is shown in TDRA table 5.

[0211] TDRA table 5

[0212]

[0213] If DCI index 0 of TDRA table 5 is indicated to the UE, the time domain resource allocation and association with TRPs will be as shown in Figure 14 corresponding to a combination of inter-slot and intra-slot scheduling.

[0214] It can be seen that the entry of DCI index 0 of TDRA table 5 differs from that of DCI index 0 of TDRA table 4 in that the total number of repetitions is indicated as “4” (instead of “3” as indicated by TDRA table 4). Thus, the time domain resources of the first, second, and third repetitions are the same as in the case of TDRA table 4, and for the sake of simplicity, the corresponding description is not repeated.

[0215] However, in the case of TDRA table 5, there is one additional subsequent repetition (the fourth repetition overall). In this example, since the association of repetitions follows an alternating pattern, and the third repetition is from TRP 1, the fourth repetition will be from TRP 2. Furthermore, based on the symbol offset of “3” and the index of the last symbol of the third repetition of “12”, the index of the starting symbol of the fourth repetition will be #15. However, in this example, the total number of symbols in each slot is only 14 (i.e., slots 0 to 13). Thus, the third repetition starts in the second slot after the PDCCH scheduled at symbol position #1, which is calculated by subtracting 14 from 15.

[0216] The length of the fourth repetition will be the same as the length of the second repetition, since the second repetition uses the same TRP as the fourth repetition. Thus, the fourth repetition will span 3 symbols (i.e., symbols #15, #16, and #17).

[0217] This embodiment (e.g., TDRA table in the form of TDRA table 3, 4, or 5) provides the advantage of a smaller table and lower DCI overhead to indicate the rows / entries of the TDRA table.

[0218] In some embodiments, an entry of the TDRA table includes an indication of a total number of transmissions, an indication of an offset between transmissions, and a single SLIV. The single SLIV indicates a starting position of time domain resources for a first transmission, and a length of time domain resources for the first transmission (e.g., for the first transmission explicitly or implicitly indicated by the entry).

[0219] As shown in TDRA table 6, in some embodiments, each entry of the TDRA table explicitly (only) indicates a single SLIV, a symbol offset, and a total number of repetitions. Specifically, in the example shown in TDRA table 6, columns 4, 5, and 6 represent the single SLIV, the symbol offset, and the total number of repetitions, respectively.

[0220] The time domain resources indicated by the single SLIV can correspond to the first transmission from the first TCI state. In other words, the single SLIV indicated by the entry can be used to calculate the starting symbol and length of the time domain resources for the first repetition starting from the first TCI state. The first TCI state can be predetermined, semi-static, and / or RRC configured.

[0221] The time domain resources (SLIV) for the subsequent repetitions can be implicitly indicated / determined using a predetermined, semi-static, and / or RRC configured pattern, and associated with the configured TCI states. For example, the subsequent repetitions can be associated with the configured TCI states in a cyclic manner.

[0222] TDRA table 6

[0223]

[0224] In an example implementation, the processor of the UE determines, for a first transmission, a starting position of time domain resources for the first transmission according to a starting position indicated by a single SLIV for the first transmission. Alternatively or additionally, the processor can determine, for the first transmission, a length of time domain resources for the first transmission according to a length indicated by the single SLIV for the first transmission. Alternatively or additionally, for each transmission that is not the first transmission, the processor can determine: i) a length of time domain resources for the transmission according to a length of time domain resources for the first transmission; ii) a starting position of time domain resources for the transmission according to: an indication of an offset, and a starting position and length of time domain resources for the first transmission; and / or iii) an association of time domain resources for the transmission with two or more TCI states according to a predetermined pattern.

[0225] Generally, the number of TRP / TCI states actually used for transmission based on the TDRA table 6 in general form and the indicated DCI index (or, in other words, based on the entries shown in the TDRA table 6) can be determined by counting all TCI states indicated by the TCI codepoint (i.e., the codepoint of the bit field that can be jointly encoded with some other parameters for the TCI indicator). Further, the total number of repetitions across all TRP / TCI states is indicated by the explicit indication in the separate column, and thus can be determined according to the explicit indication in the separate column.

[0226] The time domain resources for the first repetition can be indicated by a single SLIV, and thus can be determined from a single SLIV. In other words, the single SLIV indicated by the entry can be used to compute the starting symbol and length of the time domain resources for the first repetition starting from the first TCI state. This first TCI state can be predetermined, semi-static, and / or configured by RRC.

[0227] Further, if the total number of transmissions is greater than one, there are further / subsequent repetitions not explicitly specified by the SLIV in the TDRA entry. Here, the number of these further subsequent transmissions can correspond to the “total number of transmissions” minus “one”.

[0228] The association of these further repetitions can be determined by distributing them (e.g., uniformly) according to a pattern (e.g., in a cyclic manner) on the actually used TCI states (e.g., the TCI states indicated by the codepoint). The pattern can be predetermined, semi-static, and / or RRC configured. For example, each alternative repetition can be associated with an alternative TCI state, and / or the pattern can indicate a sequence of TCI states for the cyclic repetitions. Generally, such a predetermined pattern indicates a sequence of configured TCI states.

[0229] The length of the time domain resources for the subsequent repetitions (e.g., repetitions other than the first repetition) can be determined based on the length of the first repetition. For example, the length of the subsequent repetitions can be the same as the length of the first repetition.

[0230] The starting position (here also referred to as starting symbol) of the time domain resources (SLIV) for the subsequent repetitions can be implicitly determined / indicated using an indicated offset. More specifically, a symbol offset can be added to the starting / ending position of the time domain resources of the one repetition to obtain the starting / ending position of the time domain resources of the subsequent (e.g., consecutive) repetition. It should also be noted that generally, the time domain resources of all subsequent transmissions can be determined based on the same symbol offset. Alternatively, for each subsequent repetition, a different symbol offset can be used.

[0231] Further, the total number of repetitions associated with each configured TCI state can be determined by dividing the explicitly specified total number of repetitions by the number of TCI states actually used for transmission. Alternatively, for each entry, the total number of repetitions associated with a TCI state can be determined by counting the SLIVs in the TCI group of the entry.

[0232] A more explicit example of a TDRA table according to the present embodiment is shown in TDRA table 7.

[0233] TDRA table 7

[0234]

[0235] If the DCI index 0 of the above TDRA table 7 is indicated to the UE, the time domain resource allocation and association with TRPs will be as shown in Figure 15 .

[0236] In particular, K2 in the first entry is indicated as “1”, thus, the slot offset for starting the transmission is “1” slot after the scheduling PDCCH.

[0237] Based on the single SLIV, “{0, 3}”, the first repetition is from TRP 1, which will start from symbol #0, spanning 3 symbols. In other words, the time domain resources of the first repetition are symbols with index #0, #1 and #2.

[0238] The total number of repetitions is indicated as “3”, thus, the association and time domain resources of 2 repetitions are implicitly indicated.

[0239] In the present example, the association / grouping is based on an alternating pattern, and two TCI states are configured. Thus, the first and third repetitions are from TRP 1, while the second repetition is from TRP 2. Therefore, the total number of repetitions associated with TRP 1 is 2, and the total number of repetitions associated with TRP 2 is 1.

[0240] Further, based on the indicated offset “3” and the index of the last symbol of the first repetition “2” (in general, the last symbol of the previous repetition can be used as a reference for the offset), the second repetition will start from symbol #5. According to the length of the first repetition, the length of the second repetition is 3 symbols. Thus, in total, the second repetition will be from TRP 2, starting from symbol #5, and spanning 3 symbols (i.e. symbols #5, #6 and #7).

[0241] Further, based on the indicated offset of “3” and the index of the last symbol of the second repetition of “7”, the third repetition will start at symbol #10. Depending on the length of the first repetition, the length of the second repetition is 3 symbols. Thus, in total, the second repetition will be from TRP 1, starting at symbol #10 and spanning 3 symbols (i.e., symbols #10, #11, and #12).

[0242] This embodiment (e.g., TDRA table in the form of TDRA table 6 or 7) provides the advantage of a small TDRA table size and low DCI overhead to indicate the rows / entries of the TDRA table compared to other tables. Further, the symbol offset between repetitions allows to accommodate for beam switching delay of the UE from one TRP to another: if the transmissions with different TCI states are consecutive, the UE can not have enough time to perform beam switching to receive the transmission from the different TRP.

[0243] In another example implementation, an entry of the TDRA table includes an indication of a first SLIV, a second SLIV, and a total number of transmissions (e.g., a total number of transmissions explicitly or implicitly indicated by the entry). Here, the first SLIV can indicate a starting position of time domain resources for a first transmission, and a length of the time domain resources for the first transmission; and the second SLIV can indicate a starting position of time domain resources that are not available for transmission, and a length of the time domain resources that are not available for transmission.

[0244] As shown in TDRA table 8, in some embodiments, each entry of the TDRA table explicitly indicates a first time domain resource and a second time domain resource (e.g., by way of respective SLIVs) and a total number of repetitions. The TDRA table can also indicate a symbol offset and a PDSCH mapping type for each value of the DCI index. Specifically, in the illustrative TDRA table 8, the columns labeled “SLIV1” and “SLIV2” indicate the first and second time domain resources, respectively.

[0245] Generally, only one of the two SLIVs can indicate time domain resources for a transmission (e.g., for a first transmission of a transmission indicated by the respective entry). In other words, the first time domain resource (SLIV) can correspond to a first transmission from a first TCI state. This first TCI state can be predetermined, semi-static, and / or RRC configured.

[0246] The predetermined, semi-static, and / or RRC configured pattern can then be used to implicitly determine time domain resources (SLIVs) for subsequent repetitions (or, generally, repetitions other than the repetition explicitly indicated by the first SLIV) and associate them with configured TCI states. For example, the subsequent repetitions can be associated with configured TCI states in a cyclic manner.

[0247] The other one of the two SLIVs can indicate time domain resources that are not available for repetition. In other words, the second time domain resources (SLIV) correspond to symbols and / or time domain resources that are not available for data transmission. Then, the time domain resources for repetition, in particular for the subsequent repetitions, can be determined by taking into account that the time domain resources indicated by the second SLIV are not available for repetition.

[0248] TDRA table 8

[0249]

[0250] Generally, the number of TRP / TCI states actually used for transmission based on the TDRA table 6 in general form and the indicated DCI index (or, in other words, based on the entries shown in the TDRA table 6) can be determined by counting all TCI states indicated by the TCI codepoint (i.e., the codepoint of the bit field that can be jointly encoded with some other parameters for the TCI indicator). Moreover, the total number of repetitions of all TRP / TCI states is indicated by the explicit indication in the separate column, thus, can be determined according to the explicit indication in the separate column.

[0251] The time domain resources for the first repetition can be indicated by and determined from one of the two SLIVs, e.g., from the first SLIV. In other words, the first SLIV indicated by the entry can be used to calculate the starting symbol and length of the time domain resources for the first repetition starting from the first TCI state.

[0252] Moreover, if the total number of transmissions is greater than one, there are further / subsequent repetitions for which the SLIVs are not explicitly specified in the TDRA entry. Here, the number of these further subsequent transmissions can correspond to the “total number of transmissions” minus “one”.

[0253] The association of these further repetitions can be determined by distributing them (e.g., uniformly) according to a pattern (e.g., in a cyclic manner) on the actually used TCI states (e.g., the TCI states indicated by the codepoint). The pattern can be predetermined, semi-static, and / or RRC configured. For example, each of the further repetitions can be associated with a further TCI state. Generally, such a predetermined pattern indicates a sequence of configured TCI states.

[0254] The length of the time domain resources for the subsequent repetitions (e.g., repetitions other than the first repetition) can be determined based on the length of the first repetition. For example, the length of the subsequent repetitions can be the same as the length of the first repetition.

[0255] The starting position of the time domain resources (SLIVs) for the subsequent repetitions can be determined using an offset. The offset value can be predetermined, semi-static, and / or RRC configured. For example, the offset can be set to 1, which corresponds to a contiguous allocation of resources. For example, if there is no collision with the time resources indicated / determined by the second SLIV, the subsequent repetitions can be allocated contiguously (corresponding to an offset set to 1). However, if there is a collision between any of the time symbols of the time resources determined by the second SLIV and any of the repetitions, these particular symbols can not be used for the transmission. It is also noted that, in general, the time domain resources for all subsequent transmissions can be determined based on the same symbol offset. Alternatively, for each subsequent repetition, a different symbol offset can be used.

[0256] Further, the total number of repetitions associated with each configured TCI state can be determined by dividing the explicitly specified total number of repetitions by the number of TCI states actually used for the transmission. Alternatively, for each entry, the total number of repetitions associated with a TCI state can be determined by counting the SLIVs in the TCI group of said entry.

[0257] In some embodiments in which an entry of the TDRA table indicates time domain resources that are not available for the transmission, the processor determines a mapping of the transmission onto the time domain resources. In the mapping, the length of the time domain resources of each transmission is the same as the length indicated by the first SLIV for the first transmission. In the mapping, the transmission is mapped onto the available time domain resources of the two or more TCI states starting from the starting position of the time domain resources for the first transmission indicated by the first SLIV according to a predetermined offset. Here, the predetermined offset can indicate an interval between the time domain resources of consecutive transmissions. Each time domain resource can be associated with one of the two or more TCI states according to a predetermined pattern (in other words, the processor determines the association of the time domain resources with the two or more TCI states according to the predetermined pattern).

[0258] Here, the term “mapping” refers to the allocation of time domain resources to the transmission, wherein each allocated time domain resource is associated with one of the (configured) TRPs / TCI states. In other words, the mapping assigns / allocates the resources of the configured TCI states to the transmission.

[0259] A more explicit example of the TDRA table 8 according to the present embodiment is shown in TDRA table 9.

[0260] TDRA table 9

[0261] DCI index PDSCH mapping type K2 SLIV 1 SLIV 2 Total number of repetitions 0 B 1 {0,3} {5,1} 3 1 B 1 {0,5} {6,2} 2

[0262] If the DCI index 0 of the TDRA table 9 is indicated to the UE (and the mapping according to the present embodiment is used), the time domain resource allocation and the association with the TRPs, or in short, the mapping, would be as Figure 16 shown.

[0263] In particular, as in the previous example, the slot offset for starting the transmission is indicated as “1”, thus the first repetition starts in the slot after the DCI signaling (scheduling PDCCH).

[0264] In this example, it is further assumed that the UE is configured with a symbol offset of 1 between repetitions; two TCI states, TCI state 1 and TCI state 2, where TCI state 1 is designated as the TCI state for the first repetition; and a pattern that changes the TCI state with each repetition (in an alternating fashion).

[0265] Since the total number of repetitions is indicated as “3”, there are two subsequent repetitions, namely the second and third repetition.

[0266] Based on the configured pattern and the first TCI state, it can already be determined that there are two repetitions from TRP 1, namely the first and third repetition. Likewise, it can be determined that there is one repetition from TRP 2, namely the second repetition.

[0267] Based on the symbol offset “1” and the index of the last symbol of the first repetition “#2”, it can be determined that the second repetition starts from symbol #3.

[0268] Based on the SLIV 1 of the first entry “{0, 3}”, the first repetition will span 3 symbols, i.e., the time domain resources of the first repetition will have a length of 3 (symbols). Furthermore, since the same length as for the first repetition is used for the subsequent repetitions, the time domain resources of the second and third repetition also have a length of 3 (symbols).

[0269] According to the present embodiment, from the starting position indicated by the first SLIV, the repetitions are mapped onto (only) the available time domain resources of the configured TCI states. In detail:

[0270] Based on the SLIV 1 of the first entry “{0, 3}”, the starting position of the first repetition is symbol #0, thus the mapping starts from symbol #0. Because, for the first repetition, there is no collision with the unavailable resources, the first repetition is mapped onto symbols #0, #1 and #2.

[0271] More specifically, the second SLIV “{5, 1}” indicates that symbol #5 is unavailable for transmission. Thus, in the mapping, it can be assumed that all symbols of TRP 1 and TRP 2 are available except for symbol #5 of TRP 1 and symbol #5 of TRP 2.

[0272] Since the symbol offset is "1", the mapping will continue using the available symbol #3. Note that according to the present convention, the symbol offset is 1 between the index of the last symbol of the first repetition and the index of the first symbol of the second repetition. Therefore, the symbol offset "1" means that there is no symbol between the two consecutive transmissions.

[0273] Therefore, the second repetition will start from symbol #3. Symbol #4 is also available, therefore, symbol #4 is also allocated to the second repetition. However, since symbol #5 is not available, the mapping of the second repetition to the resources will continue using the available symbol #6. Therefore, in summary, the second repetition is mapped onto symbols #3, #4 and #6. In other words, the second repetition comprises a first part (symbols #3 and #4) and a second part (symbol #6), which are separated by symbol #5.

[0274] The mapping will continue using the available symbols #7, #8 and #9, and the third repetition will be mapped onto these symbols. Note that the entire transmission after the collision (at symbol #5) is shifted (in this example, by one symbol).

[0275] In some embodiments in which an entry of the TDRA table indicates time domain resources that are not available for transmission, the processor determines, according to a predetermined offset, a mapping of the transmissions to time domain resources (onto which the transmissions are mapped), starting from a starting position of time domain resources for a first transmission indicated by a first SLIV, onto time domain resources of the two or more TCI states. In the mapping: i) the predetermined offset indicates a gap between time domain resources of consecutive transmissions; ii) the time domain resources onto which the transmissions are mapped comprise available and unavailable time domain resources; iii) any transmission is mapped onto a time domain resource having a length indicated by the first SLIV for the first transmission, (available time domain resources and) unavailable time domain resources of which are calculated; iv) any transmission that is punctured is mapped onto a time domain resource (comprising unavailable time domain resources); and / or v) each time domain resource is associated with one of the two or more TCI states according to a predetermined pattern (in other words, the processor determines the association of the time domain resources with the two or more TCI states according to the predetermined pattern).

[0276] As mentioned above, the term "mapping" refers to the allocation of time domain resources to the transmissions, wherein each allocated time domain resource is associated with one of the (configured) TRP / TCI states. In other words, the mapping assigns / allocates the resources of the configured TCI states to the transmissions.

[0277] Another explicit example of the TDRA table 8 according to the present embodiment is shown in the TDRA table 10. Note that the TDRA table 10 corresponds to the TDRA table 9.

[0278] TDRA table 10

[0279] DCI index PDSCH mapping type K2 SLIV 1 SLIV 2 Total number of repetitions 0 B 1 {0,3} {5,1} 3 1 B 1 {0,5} {6,2} 2

[0280] If the DCI index 0 of the TDRA table 10 is indicated to the UE (and the mapping according to the present embodiment is used), the time domain resource allocation and the association with the TRPs, or in short, the mapping, will be as shown in Figure 16

[0281] Note that the present embodiment differs from the previous embodiment in that the conflicting symbols of the transmission are punctured (rather than shifted). Thus, the difference mainly concerns the mapping starting from the second repetition’s conflict at symbol #5. In the following, the differences to the mapping of the previous embodiment are mainly emphasized.

[0282] According to the present embodiment, from the starting position indicated by the first SLIV, the repetitions are mapped onto the available and unavailable time domain resources of the configured TCI state. Specifically, each transmission is mapped onto time domain resources of the same length (e.g., the length explicitly indicated by the first SLIV). Here, the length of the time domain resources to which a given transmission is mapped is the “length of the available time domain resources to which the given transmission is mapped” plus the “length of the unavailable time domain resources to which the given transmission is mapped”. In other words, the unavailable resources to which a transmission is mapped count / contribute to the length of the time domain resources to which the transmission is mapped. In detail:

[0283] Based on the SLIV1 of the first entry “{0, 3}”, the starting position of the first repetition is symbol #0, thus, the mapping starts at symbol #0. Moreover, each repetition has the same length “3”. Note that in the present embodiment, the repetitions are also mapped on unavailable time domain resources, thus, these time domain resources are counted as the length of the repetitions. In other words, in the present embodiment, the total number of symbols to which a given repetition is mapped (i.e., the available and unavailable time domain resources) is considered as the length of said repetition.

[0284] Thus, again assuming an offset of 1, the first repetition is mapped onto symbols #0, #1, and #2; the second repetition is mapped onto symbols #3, #4, and #5; and the third repetition is mapped onto symbols #6, #7, and #8.

[0285] However, as in the aforementioned embodiment, symbol #5 to which the second repetition is mapped is unavailable.

[0286] Thus, according to the present embodiment, the first entry of the TDRA table 10 (implicitly) indicates only symbols #3 and #4 for the second repetition. In other words, the second repetition is punctured to match the length of the available resources to which the second repetition is mapped.

[0287] ​This embodiment (e.g., TDRA table in the form of TDRA table 8, 9, or 10) allows for indicating time domain resources that are not available for transmission. This can facilitate scheduling of available time domain resources without causing conflicts with unavailable resources.

[0288] In general, the processor can determine 1020 the TDRA table from at least two predetermined TDRA tables according to the TCI indicator.

[0289] In some embodiments, the UE is configured with more than one TDRA table. As Figure 10 As shown, the UE can be configured 1000 with an old TDRA table and a new TDRA table by RRC. For example, the old TDRA table can indicate time domain resources for only one TCI state, while the new TDRA table can indicate time domain resources for two or more TCI states. In general, when the TCI indicator indicates no more than one TCI state indicated / configured in the DCI signaling, the UE can then be configured to use the old TDRA table. However, when the TCI indicator indicates multiple TCI states indicated / configured in the corresponding DCI signaling, the UE can be configured to use the new TDRA table (i.e., obtain entries from the new TDRA table instead of the old TDRA table). In general, the TCI indicator does not have to be represented as a separate bit field. It can be indicated together with another parameter or other parameters. In other words, one or more codepoints of such a joint bit field can indicate that one TRP is employed, while one or more other codepoints can indicate that two TRPs are employed. Similarly, any number of TRPs can be signaled by one or more codepoints of a joint bit field carrying such a TCI indicator.

[0290] Figure 10is an exemplary method for a UE. In step 1000, the UE is reconfigured via RRC signaling using old_TDRA_table and new_TDRA_table. old_TDRA_table is a table for the case that only one TRP is active, and new_TDRA_table is a table for the case that two or more TRPs are active in order to transmit and / or receive data by the UE. In step 1010, the UE receives a scheduling DCI (e.g., on a PDCCH that the UE monitors) and checks the codepoint for TCI indication. In step 1020, the UE evaluates (estimates / judges) whether the TCI indication indicates more than one TCI state. If more than one TCI state is indicated (yes in step 1020), the UE uses the new_TDRA_table in step 1030. In other words, the UE adopts the new table for determining resource allocation. Then, in step 1040, the UE determines the total number of repetitions and the time-domain resources for each transmission (e.g., each repetition). Note that the present invention is not limited to repetitions, and the transmissions can also be transmissions of different transport blocks. The order of steps 1030 and 1040 can be reversed. In step 1050, the UE associates each repetition (or, generally, transmission) with one of the indicated TCI states. The repetitions (transmissions) can be associated with the same or different TCI states. Finally, in step 1060, the UE receives data (or transmits data) in the downlink on the allocated and associated resources from the multiple TRPs (TCI states).

[0291] If in step 1020, only one TCI state is indicated (no in step 1020), the UE uses (applies) the old_TDRA_table in step 1035. In step 1045, the UE determines the time-domain resources for the respective transmission. In step 1055, the UE associates the transmission with the only indicated TCI state. Finally, in step 1065, the UE receives the data transmission from one TRP on the allocated resources.

[0292] For example, in NR Rel. 16, it has been agreed to use the codepoint of the TCI bitfield to indicate 2 TCI states (instead of 1 TCI state in Rel. 15), which basically means that 2-TRP transmission is possible.

[0293] Switching the TDRA table to be used / applied according to the TCI indicator provides flexibility to change the TDRA table.

[0294] Generally, the transmissions can be repetitions of the same data part.

[0295] Figure 18 Methods performed at both a UE and a base station in communication with each other are shown.

[0296] According to another embodiment, a method for a user equipment, UE, is provided. The method comprises a step S1840 of receiving, within a PDCCH, DCI signaling. Further, the method comprises a step S1850 of obtaining, from the DCI signaling, a transmission configuration indication, TCI, indicator specifying that two or more TCI states are configured; and an indication of time domain resources for transmission and an association of the time domain resources to the two or more TCI states, wherein each time domain resource is associated with one of the two or more TCI states. The method further comprises a step S1880 of, for each of the two or more TCI states, receiving or transmitting data on the time domain resources associated with the respective TCI state (and as indicated in the DCI signaling).

[0297] According to another embodiment, a method performed at a base station is provided. The method can comprise a step S1810 of performing an allocation of time domain resources of more than one TRP to be indicated to a UE for transmission. According to the allocation, in a step S1820, the base station generates DCI, downlink control information, DCI, signaling carried on a PDCCH so as to provide, within the DCI signaling, a transmission configuration indication, TCI, indicator specifying that two or more TCI states are configured; and an indication of time domain resources for transmission and an association of the time domain resources to the two or more TCI states, wherein each time domain resource is associated with one of the two or more TCI states. The method further comprises a step S1830 of transmitting the DCI signaling; and a step S1870 of, for each of the two or more TCI states, receiving or transmitting data on the time domain resources associated with the respective TCI state (and as indicated in the DCI signaling).

[0298] The present application can be realized by software, hardware, or software in cooperation with hardware. Each functional block used in the description of each embodiment described above can be partially or entirely realized by, for example, an LSI such as an integrated circuit (IC), and each process described in each embodiment can be controlled partially or entirely by the same LSI or a combination of LSIs. The LSI can be individually formed as chips, or one chip can be formed to include a part or all of the functional blocks. The LSI can include a data input and output coupled thereto. The LSI here can be referred to as an IC, a system LSI, a super LSI, or ultra LSI depending on a difference in the degree of integration. However, the technique of implementing an integrated circuit is not limited to the LSI, and can be realized by using a dedicated circuit, a general-purpose processor, or a special-purpose processor. In addition, a FPGA (field-programmable gate array) that can be programmed after manufacturing the LSI, or a reconfigurable processor in which the connections and the settings of circuit cells disposed inside the LSI can be reconfigured can be used. The present application can be realized as digital processing or analogue processing. If future integrated circuit technology replaces LSIs as a result of the advancement of semiconductor technology or other derivative technology, the functional blocks could be integrated using the future integrated circuit technology. Biotechnology can also be applied.

[0299] The present application can be realized by any type of apparatus, device, or system with communication functionality, which is referred to as a communication apparatus.

[0300] Some non-limiting examples of such communication devices include telephones (e.g., cellular (mobile) phones, smartphones), tablet computers, personal computers (PCs) (e.g., laptops, desktops, netbooks), cameras (e.g., digital still / video cameras), digital players (digital audio / video players), wearable devices (e.g., wearable cameras, smartwatches, tracking devices), game consoles, digital book readers, telehealth / telemedicine devices, and vehicles (e.g., automobiles, airplanes, ships) that provide communication functionality, and various combinations thereof.

[0301] Communication devices are not limited to be portable or movable, and can also include any type of apparatus, device, or system that is non-portable or stationary, such as a smart home appliance (e.g., a television, a digital video disk (DVD) player, a refrigerator, an air conditioner, a Game console), an industrial appliance (e.g., a robot, a drone), a medical appliance (e.g., a blood glucose meter, a heart rate meter, a blood pressure meter, a magnetic resonance imaging (MRI) machine), a terminal (e.g., a personal computer (PC), a laptop computer, a tablet computer, a hand-held computer), and any other electronic device that provides communication functionality.

[0302] Communication can include exchange of data through, for example, a cellular system, a wireless LAN system, a satellite system, or the like, and various combinations thereof.

[0303] The communication apparatus can include a device such as a controller or a sensor coupled to a communication device that performs the communication functions described in this disclosure. For example, the communication apparatus can include a controller or a sensor that generates control signals or data signals used by a communication device that performs the communication functions of the communication apparatus.

[0304] The communication apparatus can also include infrastructure such as base stations, access points, and any other device, equipment, or system that communicates with or controls such apparatuses as those in the non-limiting examples described above.

[0305] According to a first embodiment, a user equipment, UE, is provided. The UE comprises a transceiver that receives downlink control information, DCI, signaling; and a processor that obtains from the DCI signaling: a transmission configuration indication, TCI, indicator that specifies two or more TCI states are configured; and an indication of time domain resources for a transmission and an association of the time domain resources to the two or more TCI states, wherein each time domain resource is associated with one of the two or more TCI states; wherein the transceiver receives or transmits data on the time domain resources associated with the respective TCI states for each of the two or more TCI states.

[0306] According to a second embodiment, in addition to the first embodiment, the indication is an index that indicates an entry of a time domain resource assignment, TDRA, table.

[0307] According to a third embodiment, in addition to the second embodiment, the entry of the TDRA table includes two or more sets of start and length indicator values, SLIVs, wherein each set corresponds to a respective TCI state, and each SLIV corresponds to a respective transmission and indicates: a start position of a time domain resource for the respective transmission, wherein the time domain resource for the respective transmission is associated with the TCI state corresponding to the set of the respective SLIV; and a length of the time domain resource for the respective transmission.

[0308] According to a fourth embodiment, in addition to the third embodiment, each set includes no more than one SLIV; and the entry of the TDRA table includes an indication of a total number of transmissions.

[0309] According to a fifth embodiment, in addition to the fourth embodiment, the processor determines, for each set comprising one SLIV, a start position and a length of the time domain resources for the respective first transmission in dependence on the SLIV comprised in the set; and / or for each transmission that is not one of the first transmissions: an association of the time domain resources for the transmission with one of the two or more TCI states in dependence on: a pattern indicating a sequence of TCI states and corresponding to the start position of the time domain resources for the first transmission; a length of the time domain resources for the transmission in dependence on the length of the time domain resources for the respective first transmission, wherein the time domain resources for the respective first transmission and the time domain resources for the transmission are associated with the same TCI state; and / or a start position of the time domain resources for the transmission in dependence on an offset, a start position and a length of the time domain resources for a transmission preceding the transmission, wherein the offset corresponds to the start position and / or the length of the time domain resources for at least two of the first transmissions.

[0310] According to a sixth embodiment, in addition to the second embodiment, the entry of the TDRA table comprises: an indication of the total number of transmissions; an indication of an offset between transmissions; and a single SLIV indicating: a start position of the time domain resources for the first transmission, and a length of the time domain resources for the first transmission.

[0311] According to a seventh embodiment, in addition to the sixth embodiment, the processor determines, in dependence on the start position for the first transmission indicated by the single SLIV, a start position of the time domain resources for the first transmission; determines, in dependence on the length for the first transmission indicated by the single SLIV, a length of the time domain resources for the first transmission; and / or for each transmission that is not the first transmission: (i) determines a length of the time domain resources for the transmission in dependence on the length of the time domain resources for the first transmission; (ii) determines a start position of the time domain resources for the transmission in dependence on the indication of the offset, and the start position and the length of the time domain resources for the first transmission; and / or (iii) determines an association of the time domain resources for the transmission with the two or more TCI states in dependence on a predetermined pattern.

[0312] According to an eighth embodiment, in addition to the second embodiment, the entry of the TDRA table comprises: an indication of the total number of transmissions; a first SLIV indicating: (i) a start position of the time domain resources for the first transmission, and (ii) a length of the time domain resources for the first transmission; and a second SLIV indicating: (i) a start position of the time domain resources that are not for a transmission, and (ii) a length of the time domain resources that are not for a transmission.

[0313] According to a ninth embodiment, in addition to the eighth embodiment, the processor determines the mapping of the transmissions onto the time domain resources, wherein: the length of the time domain resources of each transmission is the same as the length indicated by the first SLIV for the first transmission; the transmissions are mapped onto the available time domain resources of the two or more TCI states starting from the starting position of the time domain resources for the first transmission indicated by the first SLIV according to a predetermined offset, wherein the predetermined offset indicates the interval between the time domain resources of consecutive transmissions; and each time domain resource is associated with one of the two or more TCI states according to a predetermined pattern.

[0314] According to a tenth embodiment, in addition to the eighth embodiment, the processor determines the mapping of the transmissions onto the time domain resources according to a predetermined offset onto the time domain resources of the two or more TCI states starting from the starting position of the time domain resources for the first transmission indicated by the first SLIV, wherein: the predetermined offset indicates the interval between the time domain resources of consecutive transmissions; the time domain resources onto which the transmissions are mapped comprise available and unavailable time domain resources; any transmission mapped onto a time domain resource having a length for the first transmission indicated by the first SLIV is counted as an unavailable time domain resource; any transmission mapped onto a time domain resource (including an unavailable time domain resource) is punctured; and each time domain resource is associated with one of the two or more TCI states according to a predetermined pattern.

[0315] According to an eleventh embodiment, in addition to any of the first to tenth embodiments, the processor determines the TDRA table from at least two predetermined TDRA tables according to a TCI indicator.

[0316] According to a twelfth embodiment, in addition to any of the first to eleventh embodiments, the transmissions are repetitions of the same data part.

[0317] According to a thirteenth embodiment, a base station is provided, comprising: a processor generating downlink control information, DCI, signaling indicating: a transmission configuration indication, TCI, indicator specifying that two or more TCI states are configured; and time domain resources for the transmissions and an association of the time domain resources to the two or more TCI states, wherein each time domain resource is associated with one of the two or more TCI states; and further comprising a transceiver transmitting the DCI signaling; and receiving or transmitting data on the time domain resources associated with a respective TCI state for each of the two or more TCI states.

[0318] According to a fourteenth embodiment, there is provided a method for a user equipment, UE, comprising the steps of: receiving downlink control information, DCI, signaling; and obtaining from the DCI signaling: (i) a transmission configuration indication, TCI, indicator specifying that two or more TCI states are configured; and (ii) an indication of time domain resources for transmission and an association of the time domain resources to the two or more TCI states, wherein each time domain resource is associated with one of the two or more TCI states; and for each of the two or more TCI states, receiving or transmitting data on the time domain resources associated with the respective TCI state.

[0319] According to a fifteenth embodiment, there is provided a method for a base station, comprising the steps of: generating downlink control information, DCI, signaling indicating: (i) a transmission configuration indication, TCI, indicator specifying that two or more TCI states are configured; and (ii) time domain resources for transmission and an association of the time domain resources to the two or more TCI states, wherein each time domain resource is associated with one of the two or more TCI states; transmitting the DCI signaling; and for each of the two or more TCI states, receiving or transmitting data on the time domain resources associated with the respective TCI state.

[0320] It is noted that the second to twelfth embodiments are respectively applicable to the scheduling device of the thirteenth embodiment. Furthermore, the steps performed by the circuitry and the steps of the transceiver mentioned in the above UE and base station embodiments correspond to the respective methods.

[0321] Furthermore, there is provided a non-transitory medium storing program instructions which, when executed on processing circuitry, such as a general purpose processor, perform all the steps of any of the above method embodiments.

[0322] In summary, the present disclosure relates to a user equipment, UE, and a scheduling node, and respective methods. Specifically, downlink control information, DCI, signaling carries a transmission configuration indication, TCI, indicator specifying that two or more TCI states are configured; and an indication of time domain resources for transmission and an association of the time domain resources to the two or more TCI states, wherein each time domain resource is associated with one of the two or more TCI states; wherein a transceiver receives or transmits data for each of the two or more TCI states on the time domain resources associated with the respective TCI state.

Claims

1. A user equipment, UE, comprising: a transceiver receiving a downlink control information, DCI, signaling; and a processor obtaining from the DCI signaling: - a transmission configuration indication, TCI, indicator specifying that two or more TCI states are configured; and - an indication indicating time domain resources for transmission and an association of the time domain resources to the two or more TCI states, wherein each of the time domain resources is associated to one of the two or more TCI states; wherein the transceiver receives or transmits data for each of the two or more TCI states on the time domain resources associated to the respective TCI state, wherein the indication is an index indicating an entry of a time domain resource assignment, TDRA, table, wherein the entry of the TDRA table comprises: - a start position of a time domain resource for a first transmission and a length of the time domain resource for the first transmission; and - a start position of a time domain resource not available for the transmission and a length of the time domain resource not available for the transmission.

2. The user equipment according to claim 1, wherein the entry of the TDRA table comprises two or more sets of start and length indicator values, SLIVs, wherein each set corresponds to a respective TCI state, and each SLIV corresponds to a respective transmission and indicates: - a start position of a time domain resource for the respective transmission, wherein the time domain resource for the respective transmission is associated to the TCI state corresponding to the set of the respective SLIV; and - a length of the time domain resource for the respective transmission.

3. The user equipment according to claim 2, wherein each set comprises not more than one SLIV; and the entry of the TDRA table comprises an indication of a total number of the transmissions.

4. The user equipment according to claim 3, wherein the processor: - for each set comprising one SLIV, determines a start position and a length of a time domain resource for a respective first transmission according to the SLIV comprised in the set; and / or - for each transmission that is not one of the first transmissions: o determines an association of a time domain resource for the transmission to one of the two or more TCI states according to: a pattern indicating a sequence of TCI states and corresponding to a start position of a time domain resource for the first transmission; o determines a length of the time domain resource for the transmission according to: a length of the time domain resource for a respective first transmission, wherein the time domain resource for the respective first transmission and the time domain resource for the transmission are associated to a same TCI state; and / or o determines a start position of the time domain resource for the transmission according to: an offset, a start position and a length of a time domain resource of one of the transmissions preceding the transmission, wherein the offset corresponds to a start position and / or a length of a time domain resource for at least two first transmissions.

5. The user equipment according to claim 1, wherein the entry of the TDRA table comprises: - an indication of a total number of the transmissions; - an indication of an offset between the transmissions; and - a single start and length indicator value, SLIV, indicating: o a start position of a time domain resource for a first transmission, and o a length of the time domain resource for the first transmission.

6. The user equipment of claim 5, wherein the processor: - determines the start position of the time domain resource for the first transmission according to the start position for the first transmission indicated by the single SLIV; - determines the length of the time domain resource for the first transmission according to the length for the first transmission indicated by the single SLIV; and / or - for each transmission that is not the first transmission: o determines a length of a time domain resource for the transmission according to the length of the time domain resource for the first transmission; o determines a start position of a time domain resource for the transmission according to the indication of the offset and the start position and the length of the time domain resource for the first transmission; and / or o determines an association of the time domain resource for the transmission with the two or more TCI states according to a predetermined pattern.

7. The user equipment of claim 1, wherein the processor determines the mapping of the transmissions onto the time domain resources, wherein: - the length of the time domain resource for each transmission is the same as the length for the first transmission; - the transmissions are mapped onto the available time domain resources of the two or more TCI states starting from a start position of the time domain resource for the first transmission according to a predetermined offset, wherein the predetermined offset indicates an interval between the time domain resources of consecutive transmissions; and - each of the time domain resources is associated with one of the two or more TCI states according to a predetermined pattern.

8. The user equipment of claim 1, wherein the processor determines the mapping of the transmissions onto the time domain resources, wherein the transmissions are mapped onto the time domain resources of the two or more TCI states starting from a start position of the time domain resource for the first transmission indicated by a first start and length indicator value, SLIV, according to a predetermined offset, wherein: - the predetermined offset indicates an interval between the time domain resources of consecutive transmissions; - the time domain resources onto which the transmissions are mapped comprise available and unavailable time domain resources; - any transmission is mapped onto a time domain resource having the length for the first transmission indicated by the first SLIV, counting unavailable time domain resources; - any transmission mapped onto a time domain resource comprising an unavailable time domain resource is punctured; and - each of the time domain resources is associated with one of the two or more TCI states according to a predetermined pattern.

9. The user equipment of claim 1, wherein the processor determines the TDRA table from at least two predetermined TDRA tables according to the TCI indicator.

10. The user equipment of claim 1, wherein The transmission is a repetition of the same data part.

11. A base station, comprising: a processor generating downlink control information, DCI, signaling comprising: - a transmission configuration indication, TCI, indicator indicating that two or more TCI states are configured; and - an indication indicating time domain resources for transmission and an association of the time domain resources to the two or more TCI states, wherein each of the time domain resources is associated to one of the two or more TCI states; and a transceiver, - transmitting the DCI signaling; and - receiving or transmitting data for each of the two or more TCI states on the time domain resources associated to the respective TCI state, wherein the indication is an index indicating an entry of a time domain resource assignment, TDRA, table, wherein the entry of the TDRA table comprises: - a start position of a time domain resource for a first transmission and a length of the time domain resource for the first transmission; and - a start position of a time domain resource not available for the transmission and a length of the time domain resource not available for the transmission.

12. A method for a user equipment, UE, comprising the steps of: receiving downlink control information, DCI, signaling; and obtaining from the DCI signaling: - a transmission configuration indication, TCI, indicator indicating that two or more TCI states are configured; and - an indication indicating time domain resources for transmission and an association of the time domain resources to the two or more TCI states, wherein each of the time domain resources is associated to one of the two or more TCI states; and receiving or transmitting data for each of the two or more TCI states on the time domain resources associated to the respective TCI state, wherein the indication is an index indicating an entry of a time domain resource assignment, TDRA, table, wherein the entry of the TDRA table comprises: - a start position of a time domain resource for a first transmission and a length of the time domain resource for the first transmission; and - a start position of a time domain resource not available for the transmission and a length of the time domain resource not available for the transmission.

13. A method for a base station, comprising the steps of: generating downlink control information, DCI, signaling comprising: - a transmission configuration indication, TCI, indicator indicating that two or more TCI states are configured; and - an indication indicating time domain resources for transmission and an association of the time domain resources to the two or more TCI states, wherein each of the time domain resources is associated to one of the two or more TCI states; transmitting the DCI signaling; and receiving or transmitting data for each of the two or more TCI states on the time domain resources associated to the respective TCI state, wherein the indication is an index indicating an entry of a time domain resource assignment, TDRA, table, wherein the entry of the TDRA table comprises: - a start position of a time domain resource for a first transmission and a length of the time domain resource for the first transmission; and - a start position of a time domain resource not available for the transmission and a length of the time domain resource not available for the transmission. - a start position of a time domain resource that is not available for the transmission, and a length of the time domain resource that is not available for the transmission. - a start position of a time domain resource that is not available for the transmission, and a length of the time domain resource that is not available

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