User equipment and base station involving channel measurement reporting

Abstract

The present disclosure relates to a user device comprising the following. A receiver receives, from a base station, a reference signal configuration regarding a plurality of candidate resource configurations of a reference signal transmitted by the base station to a UE. A receiver receives, from a base station, a reference signal configuration indication indicating one or more of a plurality of candidate resource configurations. The processor measures a reference signal received from the base station based on the indicated candidate resource configuration.

Description

TECHNICAL FIELD

[0001] The present disclosure is directed to methods, devices, and articles of manufacture in a communication system, such as a 3GPP communication system. BACKGROUND

[0002] Currently, the Third Generation Partnership Project (3GPP) is working on technical specifications for a new radio access technology - 5G NR (New Radio), also referred to as Fifth Generation (5G) or NR and used interchangeably herein.

[0003] One goal is to provide a single technical framework addressing all usage scenarios, requirements and deployment scenarios (see, e.g., Section 6 of 3GPP TR 38.913, e.g., Release 16.0.0 or Release 17.0.0), including at least enhanced mobile broadband (eMBB), ultra-reliable low-latency Communication (URLLC), and massive Machine-Type Communications (mMTC). For example, eMBB deployment scenarios can include indoor hotspot, dense urban, rural, urban macro, and high speed; URLLC deployment scenarios can include industrial control, mobile health care (remote

[0004] A second goal is to enable forward compatibility, which facilitates a completely new system design and / or the introduction of novel features. SUMMARY

[0005] One non-limiting and exemplary embodiment facilitates a user equipment performing an improved procedure.

[0006] In an embodiment, features of the technology disclosed herein are characterized by a user equipment comprising the following. A receiver of the UE receives, from a base station, a reference signal configuration regarding a plurality of candidate resource configurations of a reference signal transmitted by the base station to the UE. The receiver receives, from the base station, a reference signal configuration indication indicating one or more of the plurality of candidate resource configurations. A processor of the UE measures a reference signal received from the base station based on the indicated candidate resource configuration.

[0007] Additional benefits and advantages of the disclosed embodiments and variations will be apparent from the specification and drawings. Benefits and / or advantages can be obtained by means of the various embodiments and features of the specification and drawings, which need not all be provided in order to realize 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 figures and drawings.

[0009] Figure 1 An exemplary architecture of a 3GPP NR system to which the improved procedures of the present disclosure can be applied is shown;

[0010] Figure 2 is a schematic diagram showing a functional split between a NG Radio Access Network (NG-RAN) and a 5G Core Network (5GC) to which the improved procedures of the present disclosure can be applied,

[0011] Figure 3 is a sequence diagram of a Radio Resource Control (RRC) connection establishment / reconfiguration procedure to which the improved procedures of the present disclosure can be applied,

[0012] Figure 4 is a schematic diagram showing usage scenarios of eMBB, mMTC and URLLC to which the improved procedures of the present disclosure can be applied,

[0013] Figure 5 is a block diagram showing an exemplary 3GPP NR system architecture for a non-roaming scenario,

[0014] Figure 6 shows a simplified and exemplary implementation of a set of synchronization signal blocks distributed in a half frame,

[0015] Figure 7 shows a number of beams and corresponding SSB indices SSB1-SSB8 and how a gNB transmits beams in a beam sweeping manner,

[0016] Figure 8 shows a signaling diagram for CSI measurement and reporting,

[0017] Figure 9 shows an exemplary and simplified structure of a UE and a gNB,

[0018] Figure 10 shows a structure of a UE according to the basic implementation of the first to fourth solutions,

[0019] Figure 11 shows a flow chart of UE behavior according to the basic implementation of the first to fourth solutions,

[0020] Figure 12 shows a structure of a base station according to the basic implementation of the first to fourth solutions,

[0021] Figure 13 shows a flow chart of base station behavior according to the basic implementation of the first to fourth solutions,

[0022] Figure 14 a flowchart illustrating UE behavior according to an example embodiment of the first solution,

[0023] Figure 15 a flowchart illustrating UE behavior according to an example embodiment of the second solution,

[0024] Figures 16 to 18 a flowchart illustrating UE behavior according to an example embodiment of the third solution, and

[0025] Figure 19 a flowchart illustrating UE behavior according to an example embodiment of the fourth solution.

[0026] Figure 20 a flowchart illustrating UE behavior according to an example embodiment of the fourth solution. DETAILED DESCRIPTION

[0027] 5G NR system architecture and protocol stack

[0028] 3GPP has been working on the next release of the fifth generation cellular technology (5G) including the development of a new radio access technology operating in frequency ranges up to 100 GHz. The first version of the 5G standard was completed at the end of 2017, which allowed for 5G NR standard-compliant trials and commercial deployments of smartphones to continue.

[0029] The overall system architecture assumes an NG-RAN (Next Generation Radio Access Network) comprising gNBs, providing NG radio access user plane (SDAP / PDCP / RLC / MAC / PHY) and control plane (RRC) protocol terminations towards the UE. The gNBs are interconnected with each other via the Xn interface. The gNBs are also connected to the 5GC, more specifically to the AMF (Access and Mobility Management Function) (e.g. a specific core entity executing the AMF) by means of the Next Generation (NG) interface, and to the UPF (User Plane Function) (e.g. a specific core entity executing the UPF) by means of the NG-U interface. The NG-RAN architecture is illustrated in Figure 1 (see e.g. 3GPP TS 38.300 v17.2.0, section 4).

[0030] The user plane protocol stack for NR (see, e.g., 3GPP TS 38.300, section 4.4.1) includes the PDCP (Packet Data Convergence Protocol, see section 6.4 of 3GPP TS 38.300), RLC (Radio Link Control, see section 6.3 of TS 38.300) and MAC (Medium Access Control, see section 6.2 of TS 38.300) sub-layers, which are terminated 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, e.g., subclause 6.5 of TS 38.300). A control plane protocol stack is also defined for NR (see, e.g., TS 38.300, section 4.4.2). An overview of the layer 2 functionality is given in subclause 6 of TS 38.300. The functionality of the RRC layer is listed in subclause 7 of TS 38.300.

[0031] For example, the medium access control layer handles logical channel multiplexing and scheduling and scheduling-related functionality, including handling different numerologies.

[0032] The physical layer (PHY) is, for example, responsible for coding, PHY HARQ processing, modulation, multi-antenna processing, and mapping of signals 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 used for transmission of a particular transport channel, and each transport channel is mapped to a corresponding physical channel. For example, the physical channels are PRACH (Physical Random Access Channel), PUSCH (Physical Uplink Shared Channel) and PUCCH (Physical Uplink Control Channel) for the uplink and PDSCH (Physical Downlink Shared Channel), PDCCH (Physical Downlink Control Channel) and PBCH (Physical Broadcast Channel) for the downlink.

[0033] 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-experienced data rates that are about three times the data rates offered by IMT-Advanced. On the other hand, in the case of URLLC, more stringent requirements are placed on ultra-low latency (0.5 ms for user plane latency, both UL and DL) and high reliability (1-10 -5 -1 for 1 ms). Finally, mMTC can preferentially require high connection density (1,000,000 devices / km 2), large coverage in harsh environments, and very long-life battery (15 years) for low-cost devices.

[0034] Thus, an 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 work well for another use case. For example, a low latency service can prefer a shorter symbol duration (and thus a larger subcarrier spacing) and / or fewer symbols per scheduling interval (aka TTI) compared to an mMTC service. Furthermore, deployment scenarios with large channel delay spread can prefer a longer CP duration than scenarios with short delay spread. The subcarrier spacing should be optimized accordingly to preserve 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 subcarrier spacing f by the formula f = 1 / T u are directly related. In a similar way as in the LTE system, the term “resource element” can be used to denote the smallest resource unit consisting of one subcarrier of the length of one OFDM / SC-FDMA symbol.

[0035] In the new radio system 5G-NR, for each numerology and carrier, a resource grid of subcarriers and OFDM symbols is defined for the uplink and downlink, respectively. Each element in the resource grid is referred to as 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, e.g., v17.4.0, e.g., section 4). For example, downlink and uplink transmissions are organized into frames with a 10 ms duration, each frame consisting of ten subframes with a 1 ms duration, respectively. In 5G NR implementations, the number of consecutive OFDM symbols per subframe depends on the subcarrier spacing configuration. For example, for a 15-kHz subcarrier spacing, a subframe has 14 OFDM symbols (similar to LTE-compliant implementations assuming a normal cyclic prefix). On the other hand, for a 30-kHz subcarrier spacing, a subframe has two slots, each slot including 14 OFDM symbols.

[0036] 5G NR functional split between NG-RAN and 5GC

[0037] Figure 2 The functional split between NG-RAN and 5GC is shown. The NG-RAN logical nodes are gNB or ng-eNB. The 5GC has logical nodes AMF, UPF, and SMF.

[0038] In particular, the gNB and ng-eNB host the following main functions:

[0039] - 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;

[0040] - IP header compression, ciphering, and integrity protection of data;

[0041] - Selection of an AMF at UE attachment when it is not possible to determine routing to an AMF from information provided by the UE;

[0042] - Routing of user plane data to UPF(s);

[0043] - Routing of control plane information to AMF;

[0044] - Connection establishment and release;

[0045] - Scheduling and transmission of paging messages;

[0046] - Scheduling and transmission of system broadcast information (originated from AMF or OAM);

[0047] - Measurement and measurement reporting configuration for mobility and scheduling;

[0048] - Transport level packet marking in uplink;

[0049] - Session management;

[0050] - Support of network slicing;

[0051] - QoS flow management and mapping to data radio bearers;

[0052] - Support of UEs in RRC_INACTIVE state;

[0053] - Distribution function for NAS messages;

[0054] - Radio access network sharing;

[0055] - Dual connectivity;

[0056] - Tight interworking between NR and E-UTRA.

[0057] The Access and Mobility Management Function (AMF) hosts the following main functions:

[0058] - Non-Access Stratum (NAS) signaling termination;

[0059] - NAS signaling security;

[0060] - Access Stratum (AS) security control;

[0061] - Internal core network CN node signaling for mobility between 3GPP access networks;

[0062] - Idle mode UE reachability (including control and execution of paging retransmission);

[0063] - Registration area management;

[0064] - Support of intra- and inter-system mobility;

[0065] - Access authentication;

[0066] - Access authorization, including check of roaming permission;

[0067] - Mobility management control (subscription and policies);

[0068] - Support of network slicing;

[0069] - Session Management Function SMF selection.

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

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

[0072] - External PDU session point of interconnection with data networks;

[0073] - Packet routing and forwarding;

[0074] - Packet inspection and user plane part of policy rule enforcement;

[0075] - Traffic usage reporting;

[0076] - Uplink classifier to support routing traffic flows to data networks;

[0077] - Branching point to support multi-homed PDU sessions;

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

[0079] - Uplink information flow control (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 the user plane function, UPF, to route traffic to the appropriate destination;

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

[0087] - downlink data notification.

[0088] RRC connection establishment and reconfiguration procedures

[0089] Figure 3 Some interactions between UE, gNB and AMF (5GC entities) in the context of the UE transitioning from RRC_IDLE to RRC_CONNECTED for the NAS part are shown (see 3GPP TS 38.300).

[0090] RRC is the higher layer signaling (protocol) used for UE and gNB configuration. Specifically, this transition can involve the AMF preparing UE context data (including, for example, PDU session context, security keys, UE radio capabilities and UE security capabilities, etc.) and sending it to the gNB together with an INITIAL CONTEXT SETUP REQUEST. Subsequently, the gNB activates AS security with the UE, which is performed by the gNB sending a SecurityModeCommand message to the UE and by the UE responding with a SecurityModeComplete message to the gNB. After that, the gNB performs reconfiguration to setup Signaling Radio Bearer 2, SRB2, and Data Radio Bearer(s), DRB(s), by sending an RRCReconfiguration message to the UE and responding by the gNB receiving an RRCReconfigurationComplete from the UE. For a signaling-only connection, the steps related to RRCReconfiguration are skipped as there is no SRB2 and DRB setup. Finally, the gNB informs the AMF that the setup procedure has completed with an INITIAL CONTEXT SETUP RESPONSE.

[0091] Accordingly, in the present disclosure, an entity of a 5GC (e.g., AMF, SMF, etc.) is provided that includes circuitry to establish a next generation (NG) connection with a gNodeB; and a transmitter to transmit, via the NG connection, an initial context setup message to the gNodeB to cause signaling radio bearer setup between the gNodeB and a user equipment (UE). Specifically, the gNodeB transmits, via the signaling radio bearer, an RRC signaling to the UE containing a resource allocation configuration information element (IE). Subsequently, the UE performs uplink transmission or downlink reception based on the resource allocation configuration.

[0092] Use scenarios for IMT in 2020 and beyond

[0093] Figure 4 Some use cases for 5G NR are shown. In the Third Generation Partnership Project New Radio (3GPP NR), three use cases have been considered that have been envisioned by IMT-2020 to support a wide variety of services and applications. The stage 1 specification for enhanced mobile broadband (eMBB) has been included. In addition to further extending eMBB support, current and future work will also involve standardization of ultra-reliable and low-latency communications (URLLC) and massive machine-type communications. Figure 4 Some examples of envisioned use scenarios for IMT in 2020 and beyond are shown (see, e.g., ITU-R M.2083 Figure 2 ).

[0094] URLLC use cases have stringent requirements on capabilities such as throughput, latency, and availability, and have been envisioned as one of the enablers for future vertical applications such as wireless control of industrial manufacturing or production processes, remote medical surgery, distribution automation in smart grid, transportation safety, etc. The ultra-reliability of URLLC will be supported by identifying techniques that meet the requirements set by 3GPP TR 38.913. For NR URLLC in Release 15, key requirements include a target user plane latency of 0.5 ms for UL (uplink) and a target user plane latency of 0.5 ms for DL (downlink). The general URLLC requirement for one transmission of a packet 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 a physical layer perspective, reliability can be improved in a number of possible ways. The current range 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 developed (for NR URLLC key requirements), the range for achieving ultra-reliability can widen. Specific use cases for NR URLLC in Rel. 15 include augmented reality / virtual reality (AR / VR), e-health, e-safety, and mission critical applications.

[0096] Furthermore, the technical enhancements targeted by NR URLLC aim at 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 for which resources have been already allocated, and the already allocated resources are used for another transmission that has been requested later, but with lower latency / higher priority requirements. Thus, an already granted transmission is pre-empted by a later transmission. Pre-emption can be applied independently of a specific service type. For example, a transmission for service type A (URLLC) can be pre-empted by a transmission for service type B (such as eMBB). Technical enhancements for reliability improvement include dedicated CQI / MCS tables for a target BLER of 1E-5.

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

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

[0099] For NR URLLC, other use cases have been identified with more stringent requirements, such as factory automation, transportation industry, and power distribution, including factory automation, transportation industry, and power distribution. The more stringent requirements are higher reliability (up to 106 order), higher availability, packet size up to 256 bytes, time synchronization down to the order of a few ps, where the value can be 1 ps or a few ps, and short latency of about 0.5 to 1 ms, with a target user plane latency of 0.5 ms, depending on the frequency range.

[0100] Furthermore, for NR URLLC, several technical enhancements have been identified from a physical layer perspective. 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. Furthermore, PUSCH enhancements have been identified related to mini-slot level hopping and retransmission / repetition enhancements. The term "mini-slot" refers to a transmission time interval (TTI) comprising a smaller number of symbols than a slot (comprising fourteen symbols).

[0101] QoS control

[0102] The 5G QoS (Quality of Service) model is based on QoS Flows, and supports both 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). At the NAS level, a QoS Flow is thus the finest granularity of QoS differentiation in a PDU Session. A QoS Flow is identified within a PDU Session by a QoS Flow ID (QFI) carried in encapsulation headers over the NG-U interface.

[0103] 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 DRB(s) for the QoS Flow(s) of that PDU Session (depending on when the NG-RAN does so), e.g., as shown above with reference to Figure 3 The NG-RAN maps packets belonging to different PDU Sessions to different DRBs. NAS level packet filters in the UE and 5GC associate UL and DL packets with QoS Flows, while AS level mapping rules in the UE and NG-RAN associate UL and DL QoS Flows with DRBs.

[0104] Figure 5A 5G NR non-roaming reference architecture is shown (see, e.g., 3GPP TS 23.501, e.g., v16.9.0 section 4.2.3, see also v17.5.0 or v18.0.0). In Figure 4 An application function (AF) (e.g., an external application server hosting a 5G service) is exemplarily described in the middle to interact with the 3GPP core network in order to provide a service, e.g., to support application influence on traffic routing, an access network exposure function (NEF), or to interact with a policy framework for policy control (see policy control function, PCF), e.g., QoS control. Based on operator deployment, it can be allowed that application functions considered trusted by the operator directly interact with the relevant network functions. Application functions not allowed direct access to network functions interact with the relevant network functions via the NEF using the external exposure framework.

[0105] Figure 5 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. All or parts of the core network functions and application services can be deployed and run on a cloud computing environment.

[0106] Thus, in the present disclosure, there is provided an application server (e.g., an AF of the 5G architecture) comprising a transmitter and a control circuitry, the transmitter transmits a request containing QoS requirements of at least one of URLLC, eMBB, and mMTC services to at least one of functions (e.g., NEF, AMF, SMF, PCF, UPF, etc.) of the 5GC to establish a PDU session including radio bearers between a gNodeB and a UE according to the QoS requirements, and the circuitry performs the service using the established PDU session.

[0107] Synchronization signal block measurement timing configuration - SMTC - PSS / SSS, PBCH

[0108] NR has introduced the so-called synchronization signal block, SS block (SSB), which comprises a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH) (actually PBCH DMRS and PBCH data). A UE can use the PSS and SSS to find, synchronize to, and identify a network. The PBCH carries a minimum amount of system information, which includes an indication to transmit the remaining broadcast system information.

[0109] In LTE, these three signals, PSS, SSS, and PBCH, are also used, although not as part of an SSB. The three SSB components are always transmitted together in NR, e.g., they have the same periodicity. A given SSB can be repeated within a SS burst set, which can potentially be used for gNB beam sweeping transmission. The SS burst set can be limited to a certain time period, such as a 5 ms window (half-frame). For initial cell selection, a UE can assume a default SS burst set periodicity of 20 ms.

[0110] The 5G NR PSS is a physical layer specific signal used to identify radio frame boundaries and is of the type of an m-sequence. The 5G NR SSS is also a physical layer specific signal used to identify subframe boundaries and is also an m-sequence. The PSS / SSS sequence consists of complex values used by each element / sample of the sequence. Information on the current exemplary 5G implementation of PSS and SSS is available from 3GPP TS 38.211 v17.4.0 sections 7.4.2.2 and 7.4.2.3, including the corresponding sequence generation and mapping to physical resources.

[0111] The time-frequency structure of the SS / PBCH block carrying the SSS is described in TS 38.211 section 7.4.3.1. In such exemplary 5G implementation, in the time domain, the SS / PBCH block consists of 4 OFDM symbols, numbered in increasing order from 0 to 3. The distribution of the PSS, SSS, and PBCH signals within the SS / PBCH block is defined by Table 7.4.3.1-1.

[0112] In the frequency domain, the SS / PBCH block consists of 240 consecutive subcarriers, indexed from 0 to 239. Table 7.4.3.1-1 also defines the exact subcarriers used for each PSS, SSS, and PBCH signal within the SS / PBCH block.

[0113] In Figure 6 a simplified and exemplary illustration of an SSB according to the above definitions is shown in Figure 6 at the bottom the PSS, SSS, and PBCH in time and frequency domain are shown.

[0114] The timing (OFDM symbol) of the gNB transmission of the SS block (see Figure 6 ) can be defined differently. Specifically, the first symbol index of the candidate SS block start (within each half-frame with SSB) is determined according to 3GPP 38.213 v17.4.0 section 4.1 “Cell search”. Figure 6An example set of SSBs is shown in the middle, assuming starting OFDM symbols of 2, 8, 16, 22, 30, 36, 44, and 50 (SCS = 30 kHz, and frequency > 3 GHz case), where the relevant OFDM symbol numbering starts with 0 in a half frame. The number of SSBs in a set of SSBs can also be limited to a maximum of Lmax. In one example, a set of SSBs can include 4, 8, or 64 SSBs.

[0115] Candidate SS / PBCH blocks (e.g., a set of SSBs) in a half frame are indexed in time in increasing order from 0 to Lmax-1. Accordingly, each SSB within a set of SSBs is assigned a unique number (starting with 0 and increasing by 1).

[0116] Figure 6 The set of SSBs shown in the middle illustrates the case where the base station does transmit all possible candidate SSBs. However, it is not required to transmit all SSBs. Instead, the gNB can select only some of the SSBs within a set of SSBs and transmit those SSBs based on some requirements. The SSBs actually transmitted by a SSB can be referred to as a SSB pattern. A SSB pattern has essentially the same characteristics as the corresponding set of SSBs, including periodicity.

[0117] The gNB informs the UE about the SSB pattern, e.g., which SSBs are actually transmitted and which SSBs are not transmitted. This can be done, for example, by the gNB transmitting a SSB bitmap defining the SSB pattern, where each bit of the SSB bitmap relates to one SSB and identifies whether the SSB is transmitted or not. The length of the SSB bitmap depends on the applicable set of SSBs, e.g., 4, 8, or 64 bits.

[0118] In short, a set of candidate SSBs is configured for the gNB to use in a cell. Furthermore, out of the set of candidate SSBs, the gNB can then select all or less of the candidate SSBs to actually transmit, referred to as a SSB pattern.

[0119] All SSBs can be transmitted with all beams in the system. Alternatively, SSBs can be transmitted in different beams, e.g., when SSB beamforming is enabled. In that case, each SSB is transmitted on a different spatial beam, as illustrated in the middle of Figure 7 Figure 6 ​As an example assumption, there are 8 SSBs (0-7) that can be transmitted in different beams, each transmitted in a different beam direction. Thus, a form of transmission of beam sweeping of SSBs is achieved; in other words, the sweeping transmission of beams (and SSBs) is time-division multiplexed and occurs at different times. Two UEs (UE1 and UE2) will receive different SSBs at different times. Each beam has a beam index, e.g., where the beam index corresponds to the SSB index transmitted via said beam.

[0120] The SSBs are used by the UE in different mechanisms, such as for serving cell measurements, time / frequency synchronization, etc., in particular the SSB signals (e.g., PSS, SSS, PBCH).

[0121] Reference signals

[0122] Several different types of reference signals (RS) are used for 5G NR (see 3GPP TS 38.211 v17.4.0, section 7.4.1). At least the following reference signals are available in 5G NR:

[0123] • CSI-RS, Channel State Information Reference Signal, which can be used for channel state information acquisition and beam management

[0124] • PDSCH DMRS, Demodulation Reference Signal, which can be used for PDSCH demodulation

[0125] • PDCCH DMRS, Demodulation Reference Signal, which can be used for PDCCH demodulation

[0126] • PBCH DMRS, Demodulation Reference Signal, which can be used for PBCH demodulation

[0127] • PTRS, Phase Tracking Reference Signal, which can be used for phase tracking PDSCH,

[0128] • Tracking Reference Signal, which can be used for time tracking, also called “CSI-RS for tracking” (see TS 38.214)

[0129] • RIM Reference Signal

[0130] • Positioning Reference Signal

[0131] As a DL-only signal, the CSI-RS received by the UE can be used by the UE to estimate the channel and report channel quality information back to the gNB (to assist the gNB in modulation and coding scheme selection, resource allocation, beamforming, MIMO rank selection). The CSI-RS can be configured for periodic, aperiodic (e.g., DCI triggered), or semi-persistent transmission by the gNB. The CSI-RS can also be used for interference measurement (IM) and fine frequency / time tracking purposes. Specific instances of the CSI-RS can be configured for time / frequency tracking and mobility measurements. During MIMO operation, NR can use different antenna schemes based on the carrier frequency. At lower frequencies, the system uses a moderate number of active antennas for MU-MIMO and adds FDD operation. In this case, the UE can use the CSI-RS to compute CSI and report it back in the UL direction.

[0132] The CSI-RS is UE-specific; nonetheless, multiple users can share the same CSI-RS resource. In particular, the UE-specific configuration of the CSI-RS does not necessarily mean that the transmitted CSI-RS can only be used by a single device, but rather the same set of CSI-RS resources can be configured individually for multiple devices, which means that a single CSI-RS can be shared among multiple devices.

[0133] A configured CSI-RS can correspond to up to 32 antenna ports, each corresponding to a channel to be sounded. Depending on the number of antenna ports, there can be a single-port CSI-RS or a multi-port CSI-RS. A single-port CSI-RS occupies a single resource element within a resource block in the frequency domain and one time slot in the time domain. On the other hand, for a multi-port CSI-RS, multiple orthogonally transmitted per-antenna-port CSI-RS share the overall set of resource elements assigned for the configured multi-port CSI-RS. The sharing can be based on a combination of two or more of the following:

[0134] • code domain multiplexing (CDM) based on using different orthogonal patterns,

[0135] • frequency domain multiplexing (FDM) based on using different subcarriers within an OFDM symbol, and

[0136] • time domain multiplexing (TDM) based on using different OFDM symbols within a time slot.

[0137] While the CSI-RS can be configured to occur anywhere in a resource block, in practice some restrictions can be imposed on the CSI-RS resource allocation in order to avoid collisions with other downlink physical channels and signals. As an example, the transmission of a configured CSI-RS can be such that it does not collide with CORESETs configured for the device, with DM-RS associated with PDSCH transmission, and SS block transmission.

[0138] The 5G NR standard supports flexible CSI-RS configuration. In time domain, a CSI-RS resource can start at any OFDM symbol of a slot and span 1, 2, or 4 OFDM symbols, e.g., depending on the number of configured antenna ports.

[0139] According to one example, system information signaling (e.g., one of the system information blocks) can provide the configuration of TRS and / or CSI-RS occasions for idle and / or inactive UEs. In addition to system information, other signaling methods can be supported to configure the TRS / CSI-RS occasions, e.g., dedicated RRC messages, e.g., RRC release message.

[0140] In one example 5G NR implementation, a table (see, e.g., TS 38.211, Table 7.4.1.5.3-1) defines a set of candidate CSI-RS configurations, where each candidate CSI-RS configuration defines a set of resource elements (within a slot) on which a reference signal is transmitted. Different CSI-RS configurations differ from each other, e.g., in the number of ports, density, and / or cdm type (code division multiplexing type). The gNB can use the IE CSI-RS-ResourceMapping, which configures the resource element mapping of a CSI-RS resource in time and frequency domain, to inform the UE which CSI-RS the gNB is currently transmitting.

[0141] Beam management

[0142] Beam management is a collection of Layer 1 (PHY) and Layer 2 (MAC) procedures to establish and maintain the best beam pair for good connectivity. A beam pair is composed of, e.g., a transmit beam in one link direction and a corresponding receive beam.

[0143] Before a UE can communicate with the network, it has to perform a cell search and selection procedure and obtain initial cell synchronization and system information. The first step in this procedure is to acquire frame synchronization, find out the cell identity, and decode the MIB and SIB1.

[0144] In the case of multi-antenna systems that transmit multiple beams, detecting the beams from the gNB is also part of the initial procedure (e.g., where the UE typically detects all beams in the search space).

[0145] Beam management can be divided into three main procedures:

[0146] • Initial beam establishment,

[0147] • Beam adjustment (also known as beam tracking and refinement), and

[0148] • Beam failure recovery, the details of which are described below.

[0149] Channel state information measurement framework

[0150] The network can configure the UE to perform measurements and report them according to the configuration parameters. The measurements and reporting by the UE can be based, for example, on the CSI reporting framework for 5G NR, which can generally be considered to involve two parts, one for configuration and the other for triggering of CSI reporting.

[0151] The CSI-MeasConfig IE is the highest level IE of the CSI configuration and configures not only L1-RSRP related measurements / reports for beam management, but also regular CSI related measurements / reports (such as CQI) to determine proper MIMO precoding, modulation and coding, etc.

[0152] The CSI-MeasConfig IE mainly configures three types of lists:

[0153] 1) List of RS resource sets

[0154] • Each RS resource set in the list contains one or more RS resources. For example, multiple CSI-RS resources can be configured, e.g., by NZP-CSI-RS-Resource IE, and then grouped into RS resource sets by NZP-CSI-RS-ResourceSet IE. Other possible RS resources are defined by the IEs CSI-IM-Resource and SSB-Index.

[0155] 2) List of CSI-ResourceConfig IEs

[0156] • Different CSI-ResourceConfig in the list can contain one or more different RS resource sets selected from list element 1). This can include NZP-CSI-RS-ResourceSet, CSI-IM-ResourceSet and / or CSI-SSB-ResourceSet, respectively, identified by the appropriate IDs (see, e.g., NZP-CSI-RS-ResourceSetId, CSI-IM-ResourceSetId and / or CSI-SSB-ResourceSetId).

[0157] 3) List of CSI-ReportConfig IEs.

[0158] • Different CSI-ReportConfig configurations in the list configure different CSI report instances. This is the information element that links the reporting configuration (such as by PUCCH or PUSCH) of this CSI-ReportConfig to a set of measurement resources (i.e., one of the CSI-ResourceConfig in the above list element 2). The CSI-ResourceConfigID included in the CSI-ReportConfig IE identifies the CSI-ResourceConfig IE to be used.

[0159] The measurements and reporting can be performed on a periodic, semi-periodic, or aperiodic basis in the time domain. The measurement results are reported by the UE to the gNB, e.g., as uplink control information on PUCCH or PUSCH. In one 5G compatible example, the CSI reporting is performed by the UE based on the definitions given in 3GPP TS 38.212 v17.5.0 section 6.3.

[0160] In the current 3GPP 5G system, there are two types of reference signals that can be used for measurements, SSB (see SSB index mentioned above) and CSI-RS (Channel State Information Reference Signal; see NZP-CSI-RS-Resource IE and CSI-IM-Resource IE above). SSB is always transmitted by the network and is not UE-specific, hence not flexible. For example, SSB can be used in combination with a relatively wide beam. On the other hand, CSI-RS can be specifically configured for a UE and is quite flexible regarding when and what frequency it is transmitted (time domain) and regarding the frequency domain resources. CSI-RS can be used in combination with a relatively narrow beam, as it can be configured for only one or a few UEs.

[0161] There are several reporting components of CSI (i.e., several different types of CSI) in 5G NR, e.g., based on 3GPP TS 38.214 - its section 5.2.1:

[0162] • CQI (Channel Quality Information)

[0163] • PMI (Precoding Matrix Indicator)

[0164] • CRI (CSI-RS Resource Indicator)

[0165] • SSBRI (SS / PBCH Resource Block Indicator)

[0166] • LI (Layer Indicator)

[0167] • RI (Rank Indicator)

[0168] • L1-RSRP, and / or

[0169] • Capability Index

[0170] The UE can report one or a combination of the different metrics. In general, the metrics can be grouped into two types:

[0171] • L1-RSRP related quantities (e.g., cri-RSRP and ssb-Index-RSRP, see later IE CSI-ReportConfig)

[0172] • CSI related quantities (e.g., the rest from IE CSI-ReportConfig)

[0173] The L1-RSRP related quantities are new quantities introduced in NR (Rel-15) for one of the purposes to facilitate beam management. In contrast, the CSI related quantities such as CQI are traditional and already exist in LTE. Those traditional CSI related quantities can be used by the base station to select, for example, the appropriate MIMO precoding, modulation and coding size, etc. to match the channel conditions.

[0174] The example embodiments follow the current definition of the 5G 3GPP standard, such as defined in 3GPP TS 38.331, and can involve, for example, the following information elements (IEs):

[0175] CellGroupConfig, CSI-MeasConfig, CSI-ReportConfig, CSI-ResourceConfig, NZP-CSI-RS-Resource, and NZP-CSI-RS-ResourceSet.

[0176] In short, the measurement and reporting of the LTM can be based on the CSI reporting framework of 5G. In particular, the information element (IE) CSI-MeasConfig and the information element CSI-ReportConfig indicate the parameters of the CSI reporting framework that can be used by the UE to measure and then report the measurement results.

[0177] One possible following sequence of the IEs for defining the measurement and reporting according to the CSI framework is given below:

[0178]

[0179] The following example definition of the IE CellGroupConfig is obtained from 3GPP TS 38.331 section 6.3.2:

[0180] - CellGroupConfig

[0181] The CellGroupConfig IE is used to configure a master cell group (MCG) or a secondary cell group (SCG). A cell group comprises one MAC entity, a set of logical channels with associated RLC entities, and a primary cell (SpCell) and one or more secondary cells (SCells).

[0182] CellGroupConfig information element

[0183] -- ASN1START

[0184] -- TAG-CELLGROUPCONFIG-START

[0185] -- Configuration of one Cell-Group:

[0186] CellGroupConfig ::= SEQUENCE {

[0187] cellGroupId CellGroupId,

[0188] rlc-BearerToAddModList SEQUENCE (SIZE(1..maxLC-ID)) OF RLC-BearerConfig OPTIONAL, -- NeedN

[0189] rlc-BearerToReleaseList SEQUENCE (SIZE(1..maxLC-ID)) OF LogicalChannelIdentity OPTIONAL, -- NeedN

[0190] mac-CellGroupConfig MAC-CellGroupConfigOPTIONAL, -- Need M

[0191] physicalCellGroupConfigPhysicalCellGroupConfig OPTIONAL, -- Need M

[0192] spCellConfig SpCellConfigOPTIONAL, -- Need M

[0193] sCellToAddModList SEQUENCE (SIZE(1..maxNrofSCells)) OF SCellConfig OPTIONAL, -- NeedN

[0194] sCellToReleaseList SEQUENCE (SIZE(1..maxNrofSCells)) OF SCellIndex OPTIONAL, -- NeedN

[0195] ..., [[

[0197] reportUplinkTxDirectCurrent ENUMERATED {true}OPTIONAL -- Cond BWP-Reconfig

[0198] ]], [[

[0200] bap-Address-r16 BIT STRING (SIZE (10))OPTIONAL, -- Need M

[0201] bh-RLC-ChannelToAddModList-r16 SEQUENCE (SIZE(1..maxBH-RLC-ChannelID-r16)) OF BH-RLC-ChannelConfig-r16 OPTIONAL, -- NeedN

[0202] bh-RLC-ChannelToReleaseList-r16 SEQUENCE (SIZE(1..maxBH-RLC-ChannelID-r16)) OF BH-RLC-ChannelID-r16 OPTIONAL, -- NeedN

[0203] f1c-TransferPath-r16 ENUMERATED {lte, nr,both} OPTIONAL, -- Need M

[0204] simultaneousTCI-UpdateList1-r16 SEQUENCE (SIZE(1..maxNrofServingCellsTCI-r16)) OF ServCellIndex OPTIONAL, -- NeedR

[0205] simultaneousTCI-UpdateList2-r16 SEQUENCE (SIZE(1..maxNrofServingCellsTCI-r16)) OF ServCellIndex OPTIONAL, -- NeedR

[0206] simultaneousSpatial-UpdatedList1-r16 SEQUENCE (SIZE(1..maxNrofServingCellsTCI-r16)) OF ServCellIndex OPTIONAL, -- NeedR

[0207] simultaneousSpatial-UpdatedList2-r16 SEQUENCE (SIZE(1..maxNrofServingCellsTCI-r16)) OF ServCellIndex OPTIONAL, -- NeedR

[0208] uplinkTxSwitchingOption-r16 ENUMERATED{switchedUL, dualUL} OPTIONAL, -- Need R

[0209] uplinkTxSwitchingPowerBoosting-r16 ENUMERATED {enabled}OPTIONAL -- Need R

[0210] ]], [[

[0212] reportUplinkTxDirectCurrentTwoCarrier-r16 ENUMERATED {true}OPTIONAL -- Need N

[0213] ]], [[

[0215] f1c-TransferPathNRDC-r17 ENUMERATED {mcg, scg,both} OPTIONAL, -- Need M

[0216] uplinkTxSwitching-2T-Mode-r17 ENUMERATED {enabled} OPTIONAL, -- Cond 2Tx

[0217] uplinkTxSwitching-DualUL-TxState-r17 ENUMERATED {oneT,twoT} OPTIONAL, -- Cond 2Tx

[0218] uu-RelayRLC-ChannelToAddModList-r17 SEQUENCE (SIZE(1..maxUu-RelayRLC-ChannelID-r17)) OF Uu-RelayRLC-ChannelConfig-r17

[0219] OPTIONAL,-- Need N

[0220] uu-RelayRLC-ChannelToReleaseList-r17 SEQUENCE (SIZE(1..maxUu-RelayRLC-ChannelID-r17)) OF Uu-RelayRLC-ChannelID-r17

[0221] OPTIONAL,-- Need N

[0222] simultaneousU-TCI-UpdateList1-r17 SEQUENCE (SIZE(1..maxNrofServingCellsTCI-r16)) OF ServCellIndex OPTIONAL, -- NeedR

[0223] simultaneousU-TCI-UpdateList2-r17 SEQUENCE (SIZE(1..maxNrofServingCellsTCI-r16)) OF ServCellIndex OPTIONAL, -- NeedR

[0224] simultaneousU-TCI-UpdateList3-r17 SEQUENCE (SIZE(1..maxNrofServingCellsTCI-r16)) OF ServCellIndex OPTIONAL, -- NeedR

[0225] simultaneousU-TCI-UpdateList4-r17 SEQUENCE (SIZE(1..maxNrofServingCellsTCI-r16)) OF ServCellIndex OPTIONAL, -- NeedR

[0226] rlc-BearerToReleaseListExt-r17 SEQUENCE (SIZE(1..maxLC-ID)) OF LogicalChannelIdentityExt-r17 OPTIONAL, -- NeedN

[0227] iab-ResourceConfigToAddModList-r17 SEQUENCE (SIZE(1..maxNrofIABResourceConfig-r17)) OF IAB-ResourceConfig-r17 OPTIONAL, --Need N

[0228] iab-ResourceConfigToReleaseList-r17 SEQUENCE (SIZE(1..maxNrofIABResourceConfig-r17)) OF IAB-ResourceConfigID-r17 OPTIONAL --Need N

[0229] ]], [[

[0231] reportUplinkTxDirectCurrentMoreCarrier-r17 ReportUplinkTxDirectCurrentMoreCarrier-r17 OPTIONAL -- Need N ]]

[0233] }

[0234] -- Serving cell specific MAC and PHY parameters for a SpCell:

[0235] SpCellConfig ::= SEQUENCE {

[0236] servCellIndex ServCellIndex OPTIONAL, --Cond SCG

[0237] reconfigurationWithSync ReconfigurationWithSyncOPTIONAL, -- Cond ReconfWithSync

[0238] rlf-TimersAndConstants SetupRelease { RLF-TimersAndConstants} OPTIONAL, -- Need M

[0239] rlmInSyncOutOfSyncThreshold ENUMERATED {n1} OPTIONAL,-- Need S

[0240] spCellConfigDedicated ServingCellConfig OPTIONAL,-- Need M

[0241] ..., [[

[0243] lowMobilityEvaluationConnected-r17 SEQUENCE {

[0244] s-SearchDeltaP-Connected-r17 ENUMERATED {dB3, dB6,dB9, dB12, dB15, spare3, spare2, spare1},

[0245] t-SearchDeltaP-Connected-r17 ENUMERATED {s5, s10, s20,s30, s60, s120, s180, s240, s300, spare7, spare6, spare5,

[0246] spare4,spare3, spare2, spare1}

[0247] } OPTIONAL,-- Need R

[0248] goodServingCellEvaluationRLM-r17 GoodServingCellEvaluation-r17OPTIONAL, -- Need R

[0249] goodServingCellEvaluationBFD-r17 GoodServingCellEvaluation-r17 OPTIONAL, -- Need R

[0250] deactivatedSCG-Config-r17 SetupRelease {DeactivatedSCG-Config-r17} OPTIONAL -- Cond SCG-Opt ]]

[0252] }

[0253] ReconfigurationWithSync ::= SEQUENCE {

[0254] spCellConfigCommon ServingCellConfigCommon OPTIONAL, -- Need M

[0255] newUE-Identity RNTI-Value,

[0256] t304 ENUMERATED {ms50, ms100,ms150, ms200, ms500, ms1000, ms2000, ms10000},

[0257] rach-ConfigDedicated CHOICE {

[0258] uplink RACH-ConfigDedicated,

[0259] supplementaryUplink RACH-ConfigDedicated

[0260] } OPTIONAL,-- Need N

[0261] ..., [[

[0263] smtc SSB-MTC OPTIONAL-- Need S

[0264] ]], [[

[0266] daps-UplinkPowerConfig-r16 DAPS-UplinkPowerConfig-r16 OPTIONAL -- Need N

[0267] ]], [[

[0269] sl-PathSwitchConfig-r17 SL-PathSwitchConfig-r17 OPTIONAL -- Cond DirectToIndirect-PathSwitch ]]

[0271] }

[0272] DAPS-UplinkPowerConfig-r16 ::= SEQUENCE {

[0273] p-DAPS-Source-r16 P-Max,

[0274] p-DAPS-Target-r16 P-Max,

[0275] uplinkPowerSharingDAPS-Mode-r16 ENUMERATED {semi-static-mode1, semi-static-mode2, dynamic}

[0276] }

[0277] SCellConfig ::= SEQUENCE {

[0278] sCellIndex SCellIndex,

[0279] sCellConfigCommon ServingCellConfigCommon OPTIONAL, -- Cond SCellAdd

[0280] sCellConfigDedicated ServingCellConfig OPTIONAL, -- Cond SCellAddMod

[0281] ..., [[

[0283] smtc SSB-MTC OPTIONAL --Need S

[0284] ]], [[

[0286] sCellState-r16 ENUMERATED {activated}OPTIONAL, -- Cond SCellAddSync

[0287] secondaryDRX-GroupConfig-r16 ENUMERATED {true}OPTIONAL -- Cond DRX-Config2

[0288] ]], [[

[0290] preConfGapStatus-r17 BIT STRING (SIZE (maxNrofGapId-r17)) OPTIONAL, -- Cond PreConfigMG

[0291] goodServingCellEvaluationBFD-r17 GoodServingCellEvaluation-r17OPTIONAL, -- Need R

[0292] sCellSIB20-r17 SetupRelease { SCellSIB20-r17}OPTIONAL -- Need M ]]

[0294] }

[0295] SCellSIB20-r17 ::= OCTET STRING (CONTAINING SystemInformation)

[0296] DeactivatedSCG-Config-r17 ::= SEQUENCE {

[0297] bfd-and-RLM BOOLEAN, ...

[0299] }

[0300] GoodServingCellEvaluation-r17 ::= SEQUENCE {

[0301] offset-r17 ENUMERATED {db2, db4,db6, db8} OPTIONAL -- Need S

[0302] }

[0303] SL-PathSwitchConfig-r17 ::= SEQUENCE {

[0304] targetRelayUE-Identity-r17 SL-SourceIdentity-r17,

[0305] t420-r17 ENUMERATED {ms50, ms100,ms150, ms200, ms500, ms1000, ms2000, ms10000}, ...

[0307] }

[0308] IAB-ResourceConfig-r17 ::= SEQUENCE {

[0309] iab-ResourceConfigID-r17 IAB-ResourceConfigID-r17,

[0310] slotList-r17 SEQUENCE (SIZE (1..5120)) OFINTEGER (0..5119) OPTIONAL, -- Need M

[0311] periodicitySlotList-r17 ENUMERATED {ms0p5, ms0p625,ms1, ms1p25, ms2, ms2p5, ms5, ms10, ms20, ms40, ms80, ms160} OPTIONAL,-- Need M

[0312] slotListSubcarrierSpacing-r17 SubcarrierSpacing OPTIONAL,-- Need M ...

[0314] }

[0315] IAB-ResourceConfigID-r17 ::= INTEGER(0..maxNrofIABResourceConfig-1-r17)

[0316] ReportUplinkTxDirectCurrentMoreCarrier-r17 ::= SEQUENCE (SIZE(1..maxSimultaneousBands)) OF IntraBandCC-CombinationReqList-r17

[0317] IntraBandCC-CombinationReqList-r17::= SEQUENCE {

[0318] servCellIndexList-r17 SEQUENCE (SIZE(1..maxNrofServingCells)) OF ServCellIndex,

[0319] cc-CombinationList-r17 SEQUENCE (SIZE(1..maxNrofReqComDC-Location-r17)) OF IntraBandCC-Combination-r17

[0320] }

[0321] IntraBandCC-Combination-r17::= SEQUENCE (SIZE(1..maxNrofServingCells)) OF CC-State-r17

[0322] CC-State-r17::= SEQUENCE {

[0323] dlCarrier-r17 CarrierState-r17 OPTIONAL,

[0324] ulCarrier-r17 CarrierState-r17 OPTIONAL

[0325] }

[0326] CarrierState-r17::= CHOICE {

[0327] deActivated-r17 NULL,

[0328] activeBWP-r17 INTEGER (0..maxNrofBWPs)

[0329] }

[0330] -- TAG-CELLGROUPCONFIG-STOP

[0331] -- ASN1STOP

[0332] The definitions of the above fields and parameters of the CellGroupConfig IE are in 3GPP TS 38.331. Among the relevant ones are ServingCellConfig and ServingCellConfigCommon:

[0333]

[0334] The following exemplary definition of the IE CSI-MeasConfig is taken from 3GPP TS 38.331 section 6.3.2:

[0335] - CSI-MeasConfig

[0336] The IE CSI-MeasConfig is used to configure CSI-RS (reference signals) belonging to the serving cell in which the CSI-MeasConfig is included, channel state information reports to be transmitted on PUCCH on the serving cell in which the CSI-MeasConfig is included, and channel state information reports on PUSCH triggered by DCI received on the serving cell in which the CSI-MeasConfig is included. See also TS 38.214

[19] , clause 5.2.

[0337] CSI-MeasConfig information element

[0338] -- ASN1START

[0339] -- TAG-CSI-MEASCONFIG-START

[0340] CSI-MeasConfig ::= SEQUENCE {

[0341] nzp-CSI-RS-ResourceToAddModList SEQUENCE (SIZE(1..maxNrofNZP-CSI-RS-Resources)) OF NZP-CSI-RS-Resource OPTIONAL, -- NeedN

[0342] nzp-CSI-RS-ResourceToReleaseList SEQUENCE (SIZE(1..maxNrofNZP-CSI-RS-Resources)) OF NZP-CSI-RS-ResourceId OPTIONAL, -- NeedN

[0343] nzp-CSI-RS-ResourceSetToAddModList SEQUENCE (SIZE(1..maxNrofNZP-CSI-RS-ResourceSets)) OF NZP-CSI-RS-ResourceSet

[0344] nzp-CSI-RS-ResourceSetToReleaseList SEQUENCE (SIZE(1..maxNrofNZP-CSI-RS-ResourceSets)) OF NZP-CSI-RS-ResourceSetId

[0345] nzp-CSI-RS-ResourceSetToReleaseList SEQUENCE (SIZE(1..maxNrofNZP-CSI-RS-ResourceSets)) OF NZP-CSI-RS-ResourceSetId

[0346] nzp-CSI-RS-ResourceSetToReleaseList SEQUENCE (SIZE(1..maxNrofNZP-CSI-RS-ResourceSets)) OF NZP-CSI-RS-ResourceSetId

[0347] csi-IM-ResourceToAddModList SEQUENCE (SIZE(1..maxNrofCSI-IM-Resources)) OF CSI-IM-Resource OPTIONAL, -- NeedN

[0348] csi-IM-ResourceToReleaseList SEQUENCE (SIZE(1..maxNrofCSI-IM-Resources)) OF CSI-IM-ResourceId OPTIONAL, -- NeedN

[0349] csi-IM-ResourceSetToAddModList SEQUENCE (SIZE(1..maxNrofCSI-IM-ResourceSets)) OF CSI-IM-ResourceSet OPTIONAL, -- NeedN

[0350] csi-IM-ResourceSetToReleaseList SEQUENCE (SIZE(1..maxNrofCSI-IM-ResourceSets)) OF CSI-IM-ResourceSetId OPTIONAL, -- NeedN

[0351] csi-SSB-ResourceSetToAddModList SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourceSets)) OF CSI-SSB-ResourceSet OPTIONAL, -- NeedN

[0352] csi-SSB-ResourceSetToReleaseList SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourceSets)) OF CSI-SSB-ResourceSetId OPTIONAL, -- NeedN

[0353] csi-ResourceConfigToAddModList SEQUENCE (SIZE(1..maxNrofCSI-ResourceConfigurations)) OF CSI-ResourceConfig

[0354] OPTIONAL,-- Need N

[0355] csi-ResourceConfigToReleaseList SEQUENCE (SIZE(1..maxNrofCSI-ResourceConfigurations)) OF CSI-ResourceConfigId

[0356] OPTIONAL,-- Need N

[0357] csi-ReportConfigToAddModList SEQUENCE (SIZE(1..maxNrofCSI-ReportConfigurations)) OF CSI-ReportConfig OPTIONAL, -- NeedN

[0358] csi-ReportConfigToReleaseList SEQUENCE (SIZE(1..maxNrofCSI-ReportConfigurations)) OF CSI-ReportConfigId

[0359] OPTIONAL,-- Need N

[0360] reportTriggerSize INTEGER (0..6) OPTIONAL, --Need M

[0361] aperiodicTriggerStateList SetupRelease { CSI-AperiodicTriggerStateList} OPTIONAL, -- Need M

[0362] semiPersistentOnPUSCH-TriggerStateList SetupRelease { CSI-SemiPersistentOnPUSCH-TriggerStateList} OPTIONAL, -- Need M

[0363] ..., [[

[0365] reportTriggerSizeDCI-0-2-r16 INTEGER (0..6) OPTIONAL --Need R

[0366] ]], [[

[0368] sCellActivationRS-ConfigToAddModList-r17 SEQUENCE (SIZE(1..maxNrofSCellActRS-r17)) OF SCellActivationRS-Config-r17 OPTIONAL, --Need N

[0369] sCellActivationRS-ConfigToReleaseList-r17 SEQUENCE (SIZE(1..maxNrofSCellActRS-r17)) OF SCellActivationRS-ConfigId-r17 OPTIONAL --Need N ]]

[0371] }

[0372] -- TAG-CSI-MEASCONFIG-STOP

[0373] -- ASN1STOP

[0374] The definitions of the above fields and parameters of the CSI-MeasConfig IE are in 3GPP TS 38.331. Relevant excerpts include the following:

[0375]

[0376] The following exemplary definition of the IE CSI-ReportConfig is taken from 3GPP TS 38.331:

[0377] -CSI-ReportConfig

[0378] The IE CSI-ReportConfig is used to configure a periodic or semi-persistent report transmitted on PUCCH on the cell in which the CSI-ReportConfig is included, or to configure a semi-persistent or aperiodic report transmitted on PUSCH triggered by DCI received on the cell in which the CSI-ReportConfig is included (in this case, the cell on which the report is transmitted is determined by the received DCI). See TS 38.214

[19] , clause 5.2.1.

[0379] CSI-ReportConfig information element

[0380] -- ASN1START

[0381] -- TAG-CSI-REPORTCONFIG-START

[0382] CSI-ReportConfig ::= SEQUENCE {

[0383] reportConfigId CSI-ReportConfigId,

[0384] carrier ServCellIndex OPTIONAL,-- Need S

[0385] resourcesForChannelMeasurement CSI-ResourceConfigId,

[0386] csi-IM-ResourcesForInterference CSI-ResourceConfigIdOPTIONAL,--Need R

[0387] nzp-CSI-RS-ResourcesForInterference CSI-ResourceConfigIdOPTIONAL, -- Need R

[0388] reportConfigType CHOICE {

[0389] periodic SEQUENCE {

[0390] reportSlotConfig CSI-ReportPeriodicityAndOffset,

[0391] pucch-CSI-ResourceList SEQUENCE (SIZE(1..maxNrofBWPs)) OF PUCCH-CSI-Resource

[0392] },

[0393] semiPersistentOnPUCCH SEQUENCE {

[0394] reportSlotConfig CSI-ReportPeriodicityAndOffset,

[0395] pucch-CSI-ResourceList SEQUENCE (SIZE(1..maxNrofBWPs)) OF PUCCH-CSI-Resource

[0396] },

[0397] semiPersistentOnPUSCH SEQUENCE {

[0398] reportSlotConfig ENUMERATED {sl5, sl10,sl20, sl40, sl80, sl160, sl320},

[0399] reportSlotOffsetList SEQUENCE (SIZE (1..maxNrofUL-Allocations)) OF INTEGER(0..32),

[0400] p0alpha P0-PUSCH-AlphaSetId

[0401] },

[0402] aperiodic SEQUENCE {

[0403] reportSlotOffsetList SEQUENCE (SIZE(1..maxNrofUL-Allocations)) OF INTEGER(0..32)

[0404] }

[0405] },

[0406] reportQuantity CHOICE {

[0407] none NULL,

[0408] cri-RI-PMI-CQI NULL,

[0409] cri-RI-i1 NULL,

[0410] cri-RI-i1-CQI SEQUENCE {

[0411] pdsch-BundleSizeForCSI ENUMERATED {n2, n4}OPTIONAL--Need S

[0412] },

[0413] cri-RI-CQI NULL,

[0414] cri-RSRP NULL,

[0415] ssb-Index-RSRP NULL,

[0416] cri-RI-LI-PMI-CQI NULL

[0417] },

[0418] reportFreqConfiguration SEQUENCE {

[0419] cqi-FormatIndicator ENUMERATED { widebandCQI,subbandCQI} OPTIONAL, -- Need R

[0420] pmi-FormatIndicator ENUMERATED { widebandPMI, subbandPMI} OPTIONAL, -- Need R

[0421] csi-ReportingBand CHOICE {

[0422] subbands3 BIT STRING(SIZE(3)),

[0423] subbands4 BIT STRING(SIZE(4)),

[0424] subbands5 BIT STRING(SIZE(5)),

[0425] subbands6 BIT STRING(SIZE(6)),

[0426] subbands7 BIT STRING(SIZE(7)),

[0427] subbands8 BIT STRING(SIZE(8)),

[0428] subbands9 BIT STRING(SIZE(9)),

[0429] subbands10 BIT STRING(SIZE(10)),

[0430] subbands11 BIT STRING(SIZE(11)),

[0431] subbands12 BIT STRING(SIZE(12)),

[0432] subbands13 BIT STRING(SIZE(13)),

[0433] subbands14 BIT STRING(SIZE(14)),

[0434] subbands15 BIT STRING(SIZE(15)),

[0435] subbands16 BIT STRING(SIZE(16)),

[0436] subbands17 BIT STRING(SIZE(17)),

[0437] subbands18 BIT STRING(SIZE(18)),

[0438] ...,

[0439] subbands19-v1530 BIT STRING(SIZE(19))

[0440] } OPTIONAL -- Need S

[0441] } OPTIONAL, -- Need R

[0442] timeRestrictionForChannelMeasurements ENUMERATED{configured, notConfigured},

[0443] timeRestrictionForInterferenceMeasurements ENUMERATED{configured, notConfigured},

[0444] codebookConfig CodebookConfigOPTIONAL, -- Need R

[0445] dummy ENUMERATED {n1,n2} OPTIONAL, -- Need R

[0446] groupBasedBeamReporting CHOICE {

[0447] enabled NULL,

[0448] disabled SEQUENCE {

[0449] nrofReportedRS ENUMERATED {n1,n2, n3, n4} OPTIONAL -- Need S

[0450]

[0451] },

[0452] cqi-Table ENUMERATED {table1, table2, table3,table4-r17} OPTIONAL, -- Need R ​

[0453] subbandSize ENUMERATED {value1, value2},

[0454] non-PMI-PortIndication SEQUENCE (SIZE (1..maxNrofNZP-CSI-RS-ResourcesPerConfig)) OF PortIndexFor8Ranks OPTIONAL, -- Need R

[0455] ..., [[

[0457] semiPersistentOnPUSCH-v1530 SEQUENCE {

[0458] reportSlotConfig-v1530 ENUMERATED {sl4, sl8,sl16}

[0459] } OPTIONAL -- NeedR

[0460] ]], [[

[0462] semiPersistentOnPUSCH-v1610 SEQUENCE {

[0463] reportSlotOffsetListDCI-0-2-r16 SEQUENCE (SIZE (1..maxNrofUL-Allocations-r16)) OF INTEGER(0..32) OPTIONAL, -- Need R

[0464] reportSlotOffsetListDCI-0-1-r16 SEQUENCE (SIZE (1..maxNrofUL-Allocations-r16)) OF INTEGER(0..32) OPTIONAL -- Need R

[0465] } OPTIONAL, --Need R

[0466] aperiodic-v1610 SEQUENCE {

[0467] reportSlotOffsetListDCI-0-2-r16 SEQUENCE (SIZE (1..maxNrofUL-Allocations-r16)) OF INTEGER(0..32) OPTIONAL, -- Need R

[0468] reportSlotOffsetListDCI-0-1-r16 SEQUENCE (SIZE (1..maxNrofUL-Allocations-r16)) OF INTEGER(0..32) OPTIONAL -- Need R

[0469] } OPTIONAL, --Need R

[0470] reportQuantity-r16 CHOICE {

[0471] cri-SINR-r16 NULL,

[0472] ssb-Index-SINR-r16 NULL

[0473] } OPTIONAL, -- NeedR

[0474] codebookConfig-r16 CodebookConfig-r16OPTIONAL -- Need R

[0475] ]], [[

[0477] cqi-BitsPerSubband-r17 ENUMERATED {bits4} OPTIONAL,-- Need R

[0478] groupBasedBeamReporting-v1710 SEQUENCE {

[0479] nrofReportedGroups-r17 ENUMERATED {n1, n2, n3,n4}

[0480] } OPTIONAL, -- NeedR

[0481] codebookConfig-r17 CodebookConfig-r17 OPTIONAL,-- Need R

[0482] sharedCMR-r17 ENUMERATED {enable} OPTIONAL,--Need R

[0483] csi-ReportMode-r17 ENUMERATED {mode1, mode2}OPTIONAL, -- Need R

[0484] numberOfSingleTRP-CSI-Mode1-r17 ENUMERATED {n0, n1, n2}OPTIONAL, -- Need R

[0485] reportQuantity-r17 CHOICE {

[0486] cri-RSRP-Index-r17 NULL,

[0487] ssb-Index-RSRP-Index-r17 NULL,

[0488] cri-SINR-Index-r17 NULL,

[0489] ssb-Index-SINR-Index-r17 NULL

[0490] } OPTIONAL -- Need R

[0491] ]], [[

[0493] semiPersistentOnPUSCH-v1720 SEQUENCE {

[0494] reportSlotOffsetList-r17 SEQUENCE (SIZE (1..maxNrofUL-Allocations-r16)) OF INTEGER(0..128) OPTIONAL, -- Need R

[0495] reportSlotOffsetListDCI-0-2-r17 SEQUENCE (SIZE (1..maxNrofUL-Allocations-r16)) OF INTEGER(0..128) OPTIONAL, -- Need R

[0496] reportSlotOffsetListDCI-0-1-r17 SEQUENCE (SIZE (1..maxNrofUL-Allocations-r16)) OF INTEGER(0..128) OPTIONAL -- Need R

[0497] } OPTIONAL, -- Need R

[0498] aperiodic-v1720 SEQUENCE {

[0499] reportSlotOffsetList-r17 SEQUENCE (SIZE (1..maxNrofUL-Allocations-r16)) OF INTEGER(0..128) OPTIONAL, -- Need R

[0500] reportSlotOffsetListDCI-0-2-r17 SEQUENCE (SIZE (1..maxNrofUL-Allocations-r16)) OF INTEGER(0..128) OPTIONAL, -- Need R

[0501] reportSlotOffsetListDCI-0-1-r17 SEQUENCE (SIZE (1..maxNrofUL-Allocations-r16)) OF INTEGER(0..128) OPTIONAL -- Need R

[0502] } OPTIONAL -- Need R ]]

[0504] }

[0505] CSI-ReportPeriodicityAndOffset ::= CHOICE {

[0506] slots4 INTEGER(0..3),

[0507] slots5 INTEGER(0..4),

[0508] slots8 INTEGER(0..7),

[0509] slots10 INTEGER(0..9),

[0510] slots 16 INTEGER (0..15),

[0511] slots 20 INTEGER (0..19),

[0512] slots 40 INTEGER (0..39),

[0513] slots 80 INTEGER (0..79),

[0514] slots 160 INTEGER (0..159),

[0515] slots 320 INTEGER (0..319)

[0516] }

[0517] PUCCH-CSI-Resource ::= SEQUENCE {

[0518] uplinkBandwidthPartId BWP-Id,

[0519] pucch-Resource PUCCH-ResourceId

[0520] }

[0521] PortIndexFor8Ranks ::= CHOICE {

[0522] portIndex8 SEQUENCE{

[0523] rank1-8 PortIndex8 OPTIONAL,-- Need R

[0524] rank2-8 SEQUENCE(SIZE(2)) OFPortIndex8 OPTIONAL, -- Need R

[0525] rank3-8 SEQUENCE(SIZE(3)) OFPortIndex8 OPTIONAL, -- Need R

[0526] rank4-8 SEQUENCE(SIZE(4)) OFPortIndex8 OPTIONAL, -- Need R

[0527] rank 5-8 SEQUENCE (SIZE (5)) OF PortIndex8 OPTIONAL, -- Need R

[0528] rank 6-8 SEQUENCE (SIZE (6)) OF PortIndex8 OPTIONAL, -- Need R

[0529] rank 7-8 SEQUENCE (SIZE (7)) OF PortIndex8 OPTIONAL, -- Need R

[0530] rank 8-8 SEQUENCE (SIZE (8)) OF PortIndex8 OPTIONAL -- Need R

[0531] },

[0532] portIndex4 SEQUENCE{

[0533] rank 1-4 PortIndex4 OPTIONAL,-- Need R

[0534] rank 2-4 SEQUENCE (SIZE (2)) OF PortIndex4 OPTIONAL, -- Need R

[0535] rank 3-4 SEQUENCE (SIZE (3)) OF PortIndex4 OPTIONAL, -- Need R

[0536] rank 4-4 SEQUENCE (SIZE (4)) OF PortIndex4 OPTIONAL -- Need R

[0537] },

[0538] portIndex2 SEQUENCE{

[0539] rank 1-2 PortIndex2 OPTIONAL,-- Need R

[0540] rank 2-2 SEQUENCE (SIZE (2)) OF PortIndex2 OPTIONAL -- Need R

[0541] },

[0542] portIndexl NULL

[0543] }

[0544] PortIndex8 ::= INTEGER (0..7)

[0545] PortIndex4 ::= INTEGER (0..3)

[0546] PortIndex2 ::= INTEGER (0..1)

[0547] -- TAG-CSI-REPORTCONFIG-STOP

[0548] -- ASN1STOP

[0549] The definitions of the above fields and parameters of the CSI-ReportConfig IE are in 3GPP TS 38.331. Among the relevant ones include the following:

[0550]

[0551] The following exemplary definition of the IE CSI-ResourceConfig is obtained from 3GPP TS 38.331 section 6.3.2:

[0552] -CSI-ResourceConfig

[0553] The IE CSI-ResourceConfig defines a set of one or multiple NZP-CSI-RS-ResourceSet, CSI-IM-ResourceSet and / or CSI-SSB-ResourceSet.

[0554] CSI-ResourceConfig information element

[0555] -- ASN1START

[0556] -- TAG-CSI-RESOURCECONFIG-START

[0557] CSI-ResourceConfig ::= SEQUENCE {

[0558] csi-ResourceConfigId CSI-ResourceConfigId,

[0559] csi-RS-ResourceSetList CHOICE {

[0560] nzp-CSI-RS-SSB SEQUENCE {

[0561] nzp-CSI-RS-ResourceSetList SEQUENCE (SIZE(1..maxNrofNZP-CSI-RS-ResourceSetsPerConfig)) OF NZP-CSI-RS-ResourceSetId

[0562] OPTIONAL,-- Need R

[0563] csi-SSB-ResourceSetList SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourceSetsPerConfig)) OF CSI-SSB-ResourceSetId OPTIONAL-- Need R

[0564] },

[0565] csi-IM-ResourceSetList SEQUENCE (SIZE (1..maxNrofCSI-IM-ResourceSetsPerConfig)) OF CSI-IM-ResourceSetId

[0566] },

[0567] bwp-Id BWP-Id,

[0568] resourceType ENUMERATED { aperiodic,semiPersistent, periodic},

[0569] ..., [[

[0571] csi-SSB-ResourceSetListExt-r17 CSI-SSB-ResourceSetIdOPTIONAL -- Need R ]]

[0573] }

[0574] -- TAG-CSI-RESOURCECONFIG-STOP

[0575] -- ASN1STOP

[0576] The definitions of the above fields and parameters of the CSI-ResourceConfig IE are in 3GPP TS 38.331. Relevant ones include the following:

[0577]

[0578] Figure 8 An example and simplified signaling exchange for measurement reporting is shown, which assumes periodic transmission of reference signals and reporting. As evident from the middle, the gNB configures the UE for measurement and reporting (e.g., as described above). The UE follows the configuration for measurement and reporting processing. The gNB transmits reference signals, and the UE performs the configured measurements on the received reference signals and generates a CSI report, which it then transmits to the gNB. This can be performed repeatedly, e.g., periodically as configured.

[0579] Network energy saving

[0580] Network energy saving is very important for environmental sustainability, reducing environmental impact, and saving operational costs. 3GPP is currently studying network energy saving for Release 18, and a new work item has been approved. During the previous study phase, a network energy consumption model for base stations was defined, and potential network energy saving techniques can be categorized into different domains, including time, frequency, spatial, and power domains. Techniques in the time and frequency domains are mainly aimed at reducing the energy consumption of the dynamic part by trying to close more symbols on one or more carriers to achieve BS micro-sleep. Techniques in the spatial and power domains are mainly aimed at reducing the energy consumption of the TRX (transmit) chain and PA (power amplifier) by trying to close more spatial elements and / or reduce the transmit power / power spectral density or improve PA efficiency.

[0581] One of the goals of the new work item is to specify the following techniques in the spatial and power domains:

[0582] • Specify necessary enhancements of CSI and beam management related procedures, including measurement and reporting, and signaling, to enable efficient adaptation of spatial elements (e.g., antenna ports, active transceiver chains) [RAN1, RAN2]

[0583] • Specify necessary enhancements of CSI related procedures, including measurement and reporting, and signaling, to enable efficient adaptation of power offset values between PDSCH and CSI-RS [RAN1, RAN2]

[0584] • Note: The above goals are only for UE-specific channels / signals

[0585] • Note: Legacy UE CSI / CSI-RS capabilities apply when considering the total number of CSI reports and requirements.

[0586] Further improvements

[0587] To support network energy saving, the UE can need to report multiple CSI in one or multiple occasions based on multiple assumed antenna and / or transmit power settings.

[0588] Hence, the required number of CSI reports can increase and be more than in legacy MIMO techniques, such that UE side measurement, CSI processing and CSI control overhead can be high demanding for the UE, which can require high UE capability, energy consumption and system overhead.

[0589] Hence, the inventors identified the possibility to define an improved CSI measurement and reporting procedure in order to avoid or mitigate one or more of the above-mentioned drawbacks. The present invention relates to different solutions and variants for such an improved CSI measurement and reporting procedure.

[0590] For example, multiple CSI reporting rules can be defined to achieve one or more of the following advantages:

[0591] • Flexible spatial adaptation mode indication for multiple CSI reporting

[0592] • CSI measurement and processing complexity reduction

[0593] • CSI reporting overhead reduction

[0594] • CPU occupancy (defined in TS 38.214, section 5.2.1.6) mitigation

[0595] The CPU (CSI processing unit) occupancy depends on e.g. the CSI reporting type and the number of CSI to be reported

[0596] The CPU occupancy time depends on e.g. the CSI reference resource duration, the PDCCH triggering occasion (only for aperiodic CSI and initial SPS-CSI) and the transmission occasion of the PUSCH / PUCCH carrying the report.

[0597] • More flexible multiple CSI reporting resource allocation in one or multiple reporting occasions.

[0598] Embodiments

[0599] In the following, a UE, a base station and corresponding procedures to meet these requirements will be described for the new radio access technology envisaged for the 5G mobile communication system, but it can also be used in previous LTE-based mobile communication systems or future (e.g. 6G) mobile communication systems. Different implementations and variants will also be explained. The following disclosure is facilitated by the discussion and findings as described above and can for example be based at least on parts thereof.

[0600] Generally, it should be noted that a number of assumptions have been made and are made herein in order to enable a clear, concise and understandable explanation of the basic principles of the present disclosure. These assumptions are to be understood merely as examples made herein for illustrative purposes only, which examples are not necessarily essential to the present invention and should therefore not limit the scope of the present disclosure. The skilled person will realize that the principles disclosed below, and as set out in the claims, can be applied to different scenarios and in ways not explicitly described herein.

[0601] Furthermore, some of the terminology used below for procedures, entities, layers, etc. is closely related to the terminology used in the LTE / LTE-A systems or current 3GPP 5G standardization, even though certain terminology used in the context of the new radio access technology for the next communication system can not yet be fully decided or can eventually change. Therefore, terminology can change in the future without affecting the functionality of the corresponding features and solutions. The skilled person is thus aware that the solutions and their scope of protection should not be limited to the specific terminology exemplarily used herein, as a lack of updated or eventually agreed terminology, but should be understood more broadly in terms of the functionality and concepts underlying the solutions explained in the present disclosure.

[0602] A mobile station or mobile node or user terminal or user equipment (UE) is, for example, a physical entity (physical node) within a communication network. A node can have several functional entities. A functional entity refers to a software or hardware module that implements and / or provides a predetermined set of functions to other functional entities of the same or another node or network. A node can have one or more interfaces that attach the node to a communication facility or medium through which the node can communicate. Similarly, a network entity can have a logical interface that attaches the functional entity to a communication facility or medium through which the network entity can communicate with other functional entities or communication nodes.

[0603] The term "base station" or "radio base station" herein refers to a physical entity within a communication network. Like a mobile station, a base station can have several functional entities. A functional entity refers to a software or hardware module that implements and / or provides a predetermined set of functions to other functional entities of the same or another node or network. The physical entity performs some control tasks in relation to the communication devices, including one or more of scheduling and configuration. It is noted that base station functionality and communication device functionality can also be integrated within a single device. For example, a mobile terminal can also implement the functionality of a base station for other terminals. The term used in LTE is eNB (or eNodeB), while the currently used term for 5G NR is gNB. Also, the base station can be a gNB in a non-terrestrial network (NTN) NR system.

[0604] The communication between a UE and a base station is typically standardized and can be defined by different layers such as PHY, MAC, RRC, etc. (see the background discussion above).

[0605] The term “candidate resource configuration” of a reference signal can also be replaced by other terms such as “spatial adaptation pattern”, “reference signal resource pattern” (e.g. “CSI-RS resource pattern”) or “reference signal resource configuration”.

[0606] Figure 9 A general, simplified and exemplary block diagram of a user equipment (also referred to as communication device) and a scheduling device (here exemplarily assumed to be located in a base station such as an LTE eNB (alternatively referred to as ng-eNB) or a gNB in 5G NR) is shown. The UE and the eNB / gNB communicate with each other using transceivers over (wireless) physical channels, respectively.

[0607] A communication device can comprise a transceiver and a processing circuitry. The transceiver can in turn comprise and / or function as a receiver and a transmitter. The processing circuitry can be one or more hardware such as one or more processors or any LSIs. There is an input / output point (or node) between the transceiver and the processing circuitry through which the processing circuitry can control the transceiver, i.e. control the receiver and / or transmitter and exchange received / transmitted data. The transceiver as a transmitter and a receiver can comprise a RF (Radio Frequency) front-end which comprises one or more antennas, amplifiers, RF modulators / demodulators, etc. The processing circuitry can implement control tasks such as controlling the transceiver to transmit user data and control data provided by the processing circuitry and / or to receive user data and control data which are further processed by the processing circuitry. The processing circuitry can also be responsible for performing other processes such as determining, deciding, calculating, measuring, etc. The transmitter can be responsible for performing the processes of transmitting and other processes related thereto. The receiver can be responsible for performing the processes of receiving and other processes related thereto such as monitoring a channel.

[0608] The present invention relates to four different solutions (and corresponding variants) of improved CSI measurement and reporting procedures.

[0609] In connection with these solutions, improved UEs, improved base stations and improved integrated circuits are proposed which individually or together participate in the improved CSI measurement and reporting procedures. Corresponding methods for UE behavior and base station behavior are also provided. The integrated circuits can correspond to the UEs and base stations and their behavior, respectively.

[0610] As an overview, the first solution relates to first providing several candidate resource configurations of a reference signal which can be transmitted by a base station, wherein the base station then indicates to a UE to follow one or more of the previously configured several candidate resource configurations.

[0611] The second solution involves first providing a reporting configuration with several sub-configurations on how the measurement results can be configured for reporting. Then, the base station can instruct the UE to follow one or more of the previously configured sub-configurations.

[0612] The third solution involves defining improved prioritization rules for prioritizing measurement results generated based on sub-configurations of a reporting configuration (e.g., sub-configurations of the second solution).

[0613] The fourth solution involves defining improved dropping rules for not sending measurement results.

[0614] The following solutions can be based on some or a combination of the different mechanisms described above in the context of the exemplary 3GPP 5G-NR implementation, including, for example, using the signaling mechanisms for configuring 5G NR measurement reporting (e.g., using the information elements for measurement configuration and reporting) as currently defined in 3GPP.

[0615] Figure 10 A simplified and exemplary UE structure of a basic implementation according to the basics of the four solutions presented below is shown. In one example, the UE structure can be implemented based on the general UE structure explained in conjunction with Figure 9 various structural elements of the UE shown in Figure 10 may be interconnected to each other, e.g., to exchange control and user data as well as other signals, e.g., with corresponding input / output nodes (not shown). Although not shown for illustration purposes, the UE can comprise other structural elements.

[0616] As will become apparent from the Figure 10 The UE can comprise a configuration receiver, a measurement circuit, and a measurement report transmitter.

[0617] In the present case, the receiver of the UE can thus exemplarily be configured to at least partially perform one or more of receiving configuration information on a plurality of candidate resource configurations for reference signals, receiving a reference signal configuration indication, receiving a reporting configuration comprising a plurality of sub-configurations, receiving a reporting indication, etc., as will become apparent from the disclosure below.

[0618] In the present case, the processing circuit of the UE can thus exemplarily be configured to at least partially perform one or more of measuring a reference signal, generating a measurement report, determining a priority of a measurement result, determining whether to send a measurement result based on a dropping rule, etc., as will become apparent from the disclosure below.

[0619] In the present case, as will become apparent from the disclosure below, the transmitter of the UE can thus exemplarily be configured to at least partly perform one or more of transmitting a measurement report, transmitting a UE capability indication, etc.

[0620] One exemplary and basic procedure involves the UE receiving configuration information from the base station related to an improved measurement and reporting procedure according to any of the four solutions. The UE accordingly performs measurements on reference signals according to any of the four solutions. The UE then transmits one or more measurement reports to the base station, including results of measurements performed according to any of the four solutions. Figure 11 A corresponding sequence diagram illustrating exemplary UE behavior in line with the above-described UE and UE method is shown in

[0621] Some exemplary implementations of the four solutions also involve an improved base station. Accordingly, the solutions also provide for an improved base station participating therein, as will be explained below.

[0622] Figure 12 A simplified and exemplary base station structure according to the basic implementation underlying the four solutions given below is shown. In one example, the base station structure can be implemented based on the general base station structure explained in connection with Figure 9 The various structural elements of the base station shown in Figure 12 may for example be interconnected to each other, e.g. in order to exchange control and user data as well as other signals, with corresponding input / output nodes (not shown). Although not shown for illustration purposes, the base station can comprise other structural elements.

[0623] As will be apparent from the disclosure, the base station comprises a measurement report receiver and a configuration transmitter.

[0624] In the present case, as will become apparent from the disclosure below, the receiver of the base station can thus exemplarily be configured to at least partly perform one or more of receiving a measurement report and receiving a UE capability indication, etc.

[0625] In the present case, as will become apparent from the disclosure below, the processing circuitry of the base station can thus exemplarily be configured to at least partly perform one or more of generating a configuration of a UE, etc.

[0626] In the present case, as will become apparent from the disclosure below, the transmitter of the base station can thus exemplarily be configured to at least partly perform one or more of transmitting information about a configuration of a plurality of candidate resource configurations for reference signals, transmitting a reference signal configuration indication, transmitting reporting configuration information including a plurality of sub-configurations, transmitting a reporting indication, etc.

[0627] One example and basic procedure involves the base station sending configuration information to the UE related to an improved measurement and reporting procedure according to any of the four solutions. The base station can then receive one or more measurement reports from the UE, including results of measurements performed by the UE. In Figure 13 A corresponding sequence diagram illustrating example behavior consistent with the above base station and base station method is shown in

[0628] The following solutions can be based, for example, on the UE, UE method, base station, and base station method discussed above in connection with Figure 10 、 Figure 11 、 Figure 12 and Figure 13 .

[0629] First solution - candidate resource configuration of reference signals

[0630] Briefly, the first solution involves first providing a number of candidate resource configurations of reference signals that can be transmitted by a base station, where the base station then instructs a UE to follow one or more of the previously configured number of candidate resource configurations.

[0631] One example procedure according to the first solution, as will be disclosed in further more detail below, is implemented by a UE including the following. A receiver of the UE receives, from a base station, a reference signal configuration regarding a number of candidate resource configurations of reference signals that can be transmitted by the base station to the UE. The receiver receives, from the base station, a reference signal configuration indication indicating one or more of the configured number of candidate resource configurations. A processor of the UE measures, based on the indicated candidate resource configuration, a reference signal received from the base station. The processor generates one or more measurement reports including measurement results of the measured reference signal. A transmitter of the UE transmits, to the base station, the generated measurement reports.

[0632] A corresponding example method according to the first solution includes the following steps performed by a UE:

[0633] receiving, from a base station, a reference signal configuration having a number of candidate resource configurations of reference signals that can be transmitted by the base station to the UE,

[0634] receiving, from the base station, a reference signal configuration indication indicating one or more of the configured number of candidate resource configurations,

[0635] measuring, based on the indicated candidate resource configuration, a reference signal received from the base station,

[0636] generating one or more measurement reports including measurement results for the measured reference signal, and

[0637] transmitting, to the base station, the generated measurement reports.

[0638] Figure 14 A corresponding sequence diagram showing exemplary UE behavior consistent with the above UE and UE method according to the first solution is shown in Fig. 1 1.

[0639] The first solution also provides an improved base station, which can comprise the following. A processor of the base station generates a reference signal configuration with a plurality of candidate resource configurations of a reference signal that can be transmitted by the base station to a user equipment (UE). A transmitter of the base station transmits the generated reference signal configuration to the UE. The processor determines one or more candidate resource configurations of the plurality of candidate resource configurations of the configuration for the UE to use. The transmitter transmits a reference signal configuration indication to the UE indicating the determined one or more candidate resource configurations. The transmitter also transmits the reference signal to the UE. A receiver receives one or more measurement reports from the UE, the measurement reports comprising measurement results of the reference signal measured by the UE based on the indicated one or more candidate resource configurations.

[0640] According to the first solution, therefore, a flexible number of candidate resource configurations can be configured for the reference signal, while at the same time facilitating the selection of one or more of the candidate resource configurations for the UE to actually perform measurements and reporting. Moreover, by enabling the gNB to flexibly select among the previously configured configurations, an appropriate trade-off between network energy saving gains, UE processing complexity, and system overhead can be achieved.

[0641] The base station can effectively determine how to adapt spatial elements, such as antenna ports and active transceiver chains, based on information obtained from the various measurement reports and candidate transmission characteristics for the reference signal configuration. For example, if possible, network energy saving can be achieved by reducing the energy consumption of the transmit chains and power amplifiers and by using fewer antenna ports (e.g., for transmitting the reference signal).

[0642] According to one variant of the first solution, which can be combined with any other variant described herein, at least two of the plurality of candidate resource configurations differ from each other by defining a candidate transmission characteristic for the reference signal with different values. For example, the different candidate transmission characteristics are one or more of the following:

[0643] • different antenna port patterns for the reference signal,

[0644] • different transmission powers for the reference signal, and

[0645] • different transmission powers for a downlink data channel for which the reference signal is measured.

[0646] Generally, the plurality of candidate resource configurations may, for example, comprise at least one candidate resource configuration defining at least one transmission characteristic different from the transmission characteristic actually used by the base station for transmitting the reference signal to the UE, as will become apparent from the following.

[0647] In more detail, different antenna port patterns for the reference signal can be implemented in different ways. For example, one candidate antenna port pattern can be the antenna port pattern actually used by the base station for transmitting the reference signal, while another candidate antenna port pattern can be a subset of this actually used antenna port pattern. When exemplarily assuming that 16 antenna ports are used for transmitting the reference signal, one candidate antenna port pattern can be the 16 antenna port pattern actually used by the base station for transmitting the reference signal to the UE, while other candidate antenna port patterns can be a subset of 8 antenna ports out of the 16 antenna ports or 4 antenna ports out of the 16 antenna ports, etc. Correspondingly, when exemplarily assuming that 8 antenna ports are used for transmitting the reference signal, one candidate antenna port pattern can be the 8 antenna port pattern actually used by the base station for transmitting the reference signal to the UE, while other candidate antenna port patterns can be a subset of 4 antenna ports out of the 8 antenna ports or 2 antenna ports out of the 8 antenna ports, etc.

[0648] Then, when indicated by the base station and indicated to the UE using the corresponding reference signal configuration indication, the UE utilizes the indicated antenna port pattern for generating the measurement result.

[0649] Different implementations are possible regarding how to indicate different antenna port patterns for the reference signal.

[0650] One possible implementation is to use code division multiplexing, CDM, group indices for identifying the antenna port pattern. In more detail, reference signal transmission using multiple antenna ports can be implemented (at least partially) by using code domain multiplexing (i.e., using different orthogonal patterns). Accordingly, the antenna ports in the CDM domain can be grouped and then different CDM groups are identified by using suitable indices. For example, when indicating 2 out of 8 antenna ports, the CDM group {0}, {1}, {2} or {3} can be indicated. As another example, when indicating 4 out of 8 antenna ports, the CDM group {0,1} or {2,3} or other combinations can be indicated. One exemplary 5G compliant implementation can follow the CDM group indices already established for CSI-RS (see, e.g., TS 38.211 section 7.4.1.5.3; CDM group index j).

[0651] The first possible implementation is advantageous as it can be implemented by reusing known mechanisms from 5G NR, resulting in less standard specification impact. Furthermore, the antenna port pattern can be indicated with only little control overhead.

[0652] Another possible implementation is to use indices of the antenna ports to identify the antenna port pattern. Accordingly, one or more antenna port indices can be directly indicated, such as antenna ports {0}, {1}, {2}, {3}, {0, 1}, {0, 3}, {2, 3}, {0, 1, 2, 3}, or other combinations. This possible implementation provides a great flexibility of how the antenna port pattern can be indicated.

[0653] Another possible implementation is to use a combination of CDM group indices and antenna port indices (see above implementations) to identify the candidate antenna port pattern. Accordingly, the antenna port pattern can be indicated with antenna port indices across different CDM groups. For example, when indicating 2 antenna ports, a first antenna port in CDM groups 0 and 1 or 0 and 2 or other combinations can be indicated, respectively. As another example, when indicating 4 antenna ports, a first antenna port or a second antenna port in CDM groups 0, 1, 2, 3 can be indicated, respectively. This possible implementation represents a compromise between the two above implementations. Furthermore, this can reduce the interference caused by code division multiplexing within each subset.

[0654] Furthermore, with respect to different transmission powers of the reference signals, one possible implementation is to indicate a power offset with respect to the transmission of the synchronization signal block from the base station.

[0655] Further, with respect to different transmission powers of the downlink data channel for which the reference signals are measured, one possible implementation is to indicate a power offset with respect to the reference signals (i.e., between the reference signals and the downlink data channel). In one example, the downlink data channel can be the physical downlink shared channel PDSCH known in 5G NR. Furthermore, the transmission power of the downlink data channel (e.g., indicated successively by the power offset) can be the same as, higher than, or lower than the actual transmission power used by the base station for transmitting the downlink data channel.

[0656] The base station can effectively determine how to adapt the power offset values with respect to the downlink data channel (e.g., PDSCH) and the reference signals (e.g., CSI-RS) based on the information obtained from the various measurement reports and the candidate transmission characteristics configured for the reference signals.

[0657] In another variant of the first solution, which can be combined with any other variant described herein, the plurality of candidate resource configurations can further define radio resource elements in the frequency and time domain carrying the reference signal. Thus, for example, one candidate resource configuration can define radio resource elements in the frequency and time domain for the reference signal, an antenna port pattern for the reference signal, and one or two transmission powers for the reference signal (respectively downlink data channel).

[0658] One exemplary structure of how to configure the various candidate resource configurations for the reference signal is given below:

[0659] i. Resource #1 (two or more candidates)

[0660] a. Candidate antenna pattern #1

[0661] b. Candidate antenna pattern #2

[0662] c. …

[0663] ii. Resource #2 (one candidate)

[0664] a. Candidate antenna pattern #3

[0665] iii. …

[0666] iv. Resource #N

[0667] a. Candidate antenna pattern #M

[0668] As is apparent from the above, the reference signal configuration information configures resources for one or more reference signals. As described above, each radio resource is associated / configured with one or more different candidate transmission characteristics (in the above, e.g. candidate antenna patterns) for the reference signal.

[0669] Another exemplary structure of how to configure the various candidate resource configurations for the reference signal is given below:

[0670] i. Resource set #1:

[0671] a. Resource #1 (two or more candidates)

[0672] i. Candidate antenna pattern #1 (e.g. 4 ports)

[0673] ii. Candidate antenna pattern #2 (e.g. 8 ports)

[0674] iii. …

[0675] b. Resource #2 (one candidate)

[0676] i. Candidate antenna pattern #3 (e.g., 8 ports)

[0677] c. …

[0678] d. Resource #N

[0679] i. Candidate antenna pattern #M (e.g., 8 ports)

[0680] ii. Resource set #2

[0681] a. …

[0682] iii. …

[0683] iv. Resource set #K

[0684] a. …

[0685] As is apparent from the above, and in addition to the previous example structures, the reference signal configuration information configures one or more sets of radio resources for the reference signal. Each set of radio resources indicates one or more reference signals with a radio resource configuration, e.g., as presented in the previous example structures. Accordingly, the example structure further implements one higher level - the reference resource set.

[0686] In other words, one reference signal configuration can contain one or more sets of reference signal resources for the UE. Each of these sets of resources can contain one or more reference signal resources, each of which can in turn contain one or more candidate transmission properties.

[0687] Although not shown in the structure of the above configuration, according to another example variant, each candidate antenna pattern can additionally be configured with an associated transmission power for the reference signal or an associated transmission power for the downlink data channel or both.

[0688] According to a first solution, the base station, after having pre-configured the candidate resource configurations, then selects which of the candidate resource configurations the UE should use for reference signal measurements and measurement result reporting. Accordingly, the reference signal configuration indicates is transmitted by the base station to the UE, indicating one or more of the previously configured candidate resource configurations to process.

[0689] According to other variants of the first solution, which can be combined with any other variant described herein, there are several ways on how to implement the reference signal configuration indication.

[0690] In one possible implementation, the reference signal configuration indicates one or more candidate resource configurations based on a group ID. In particular, each of the plurality of candidate resource configurations is associated with one of the plurality of group IDs, such that there is an explicit one-to-one relationship between the group ID and the one or more candidate resource configurations. Furthermore, it is exemplarily assumed that one candidate resource configuration can only belong to one group.

[0691] Alternatively, the group ID is respectively associated with one or more of the candidate transmission characteristics. Correspondingly, when the group ID indicates the candidate transmission characteristics, the UE can determine the corresponding candidate resource configuration containing the indicated candidate transmission characteristics.

[0692] The association between the group ID and the candidate resource configuration (respectively the candidate transmission characteristics) can be configured in advance between the base station and the UE, e.g. using RRC messages.

[0693] In another possible implementation, the reference signal configuration indicates one or more candidate resource configurations based on a bitmap. Each bit of the bitmap can be associated with one or more of the plurality of candidate resource configurations. Correspondingly, by setting a bit to a specific value (such as 1), the bit of the bitmap indicates that the measurement of the reference signal should be based on the associated one or more candidate resource configurations.

[0694] Alternatively, the bits of the bitmap can be respectively associated with one or more of the candidate transmission characteristics. Correspondingly, when the candidate transmission characteristics are indicated by the bits, the UE can determine the corresponding candidate resource configuration containing the indicated candidate transmission characteristics.

[0695] The association between the bits of the bitmap and the candidate resource configuration (respectively the candidate transmission characteristics) can be configured in advance between the base station and the UE, e.g. using RRC messages.

[0696] In another implementation, the reference signal configuration indicates one or more candidate resource configurations based on code words. In particular, each code word can be associated with one or more of the plurality of candidate resource configurations. In one example, one candidate resource configuration can be associated with more than one code word, such that the code word based implementation is flexible in defining different combinations of candidate resource configurations to be indicated by the base station.

[0697] Alternatively, the code words can be respectively associated with one or more of the candidate transmission characteristics. Correspondingly, when the candidate transmission characteristics are indicated by the code words, the UE can determine the corresponding candidate resource configuration containing the indicated candidate transmission characteristics.

[0698] The association between the code words and the candidate resource configuration (respectively the candidate transmission characteristics) can be configured in advance between the base station and the UE, e.g. using RRC messages.

[0699] According to the 5G-compatible example embodiment, the first solution reuses at least part of the configuration structures already defined in the 3GPP standards for measurement and measurement reporting, e.g. as described above. According to one example assumption, the above-mentioned reference signal can be a CSI-RS (Channel State Information Reference Signal). Furthermore, the configuration of the CSI-RS can then be implemented identically or similarly to the CSI-ResourceConfig described above with respect to TS 38.331.

[0700] Second solution - reporting sub-configuration

[0701] In short, the second solution is directed to first providing a reporting configuration with several sub-configurations on how the reporting of the measurement results can be configured. Then, the base station can instruct the UE to follow one or more of the previously configured sub-configurations.

[0702] The second solution can be used in combination with the first solution or independently.

[0703] One example procedure according to the second solution, as will be disclosed in further more detail below, is implemented by a UE comprising the following. A receiver of the UE receives, from a base station, a reporting configuration comprising a plurality of sub-configurations. Each of the sub-configurations configures one or more of the following:

[0704] • a set of measurement reporting quantities, e.g. one or more of a channel quality parameter, a channel quality indicator, a precoding matrix indicator, a reference signal indicator, a layer indicator, a rank indicator,

[0705] • an uplink channel transmission configuration configuring one or more of a time and a frequency of a radio resource for an uplink channel, which can be used for transmitting the measurement results of the respective sub-configuration.

[0706] The receiver further receives a reporting indication indicating one or more of the sub-configurations. A processor of the UE generates a measurement report, and a transmitter transmits the measurement report to the base station based on the indicated one or more sub-configurations.

[0707] A corresponding example method according to the second solution comprises the following steps performed by a UE:

[0708] receiving, from a base station, a reporting configuration comprising a plurality of sub-configurations, each of the plurality of sub-configurations configuring one or more of the following:

[0709] • a set of measurement reporting quantities, e.g. one or more of a channel quality parameter, a channel quality indicator, a precoding matrix indicator, a reference signal indicator, a layer indicator, a rank indicator,

[0710] • an uplink channel transmission configuration configuring one or more of time and frequency of radio resources for an uplink channel that can be used to transmit measurement results of the respective sub-configuration,

[0711] receiving a reporting indication indicating one or more of the sub-configurations,

[0712] generating and transmitting a measurement report based on the indicated one or more sub-configurations.

[0713] Figure 15 A corresponding sequence diagram showing exemplary UE behavior in line with the above UE and UE method according to the second solution is shown in Fig. Figure 15 It is apparent from Fig. that the UE behavior conceptually follows the above UE and UE method. Figure 15 It is further shown that the UE performs measurements on the reference signals and then the UE generates one or more measurement reports to be transmitted to the base station based on the measurements.

[0714] Depending on the content of the sub-configuration, the UE can have to take the sub-configuration into account already when generating the measurement report, e.g. in order to include those reporting quantities indicated by the sub-configuration. The UE can have to take the sub-configuration into account also in the process of transmitting the measurement report to the base station, e.g. in order to use the configuration of the uplink channel indicated by the sub-configuration.

[0715] The second solution also provides an improved base station, which can comprise the following.

[0716] The processor of the base station can generate a reporting configuration comprising a plurality of sub-configurations, each of the plurality of sub-configurations configuring one or more of:

[0717] • a set of measurement reporting quantities, e.g. one or more of a channel quality parameter, a channel quality indicator, a precoding matrix indicator, a reference signal indicator, a layer indicator, a rank indicator,

[0718] • an uplink channel transmission configuration configuring one or more of time and frequency of radio resources for an uplink channel that can be used to transmit measurement results of the respective sub-configuration.

[0719] The transmitter of the base station subsequently transmits the reporting configuration to the UE. The processor then determines one or more of the plurality of sub-configurations for the UE to use. The transmitter transmits a reporting indication to the UE indicating the determined one or more sub-configurations. The receiver of the base station receives one or more measurement reports from the UE, including measurement results of the reference signals. The UE generates and transmits the measurement results and the measurement report based on the indicated sub-configuration.

[0720] According to the second solution, different sub-configurations of the reporting configuration can thus define one or more different sets of measurement reporting quantities and uplink channel transmission configurations. Different sub-configurations thus allow for different ways of configuring in advance which measurement results will be reported to the base station (see reporting quantities) and how the measurement results will be reported to the base station (see uplink channel transmission configurations).

[0721] The second solution can thus facilitate providing more flexibility by configuring the same or different parameters for different sub-configurations. The base station can flexibly control the details of the measurement reporting performed by the UE, and thereby control the UE processing, UE occupation, and uplink control overhead resulting from the measurements and measurement reporting.

[0722] According to one example implementation, the uplink channel transmission configuration can configure one or more of time and / or frequency resources for an uplink channel (e.g. PUCCH or PUSCH) that can be used for transmitting the measurement results of the respective sub-configuration. In one option, different sub-configurations can differ with respect to the parameters of the uplink channel transmission configuration, and more specifically, define different time or frequency radio resources. This facilitates the base station having the possibility to configure and select the most suitable uplink channel in one or more time / frequency resources for reporting the measurement results of a sub-configuration of the previously configured sub-configurations.

[0723] According to one example implementation, the set of measurement reporting quantities can include one or more of channel quality parameters, channel quality indicators, precoding matrix indicators, reference signal indicators, layer indicators, and rank indicators, among possible others. In a 5G-compatible example implementation, the reporting quantities can be L1-RSRP / SINR, CRI (CSI-RS Resource Indicator), CQI, PMI, RI, LI (Layer Indicator, which is the strongest layer indicated by the list of precoder matrices of the reported PMI corresponding to the maximum reported wideband CQI).

[0724] Any suitable combination of reporting quantities can be configured in a sub-configuration. In one option, different sub-configurations can differ with respect to the reporting quantities, and more specifically, with respect to the total number of reporting quantities and / or which reporting quantities are configured by the sub-configuration. This facilitates the base station having the possibility to select the most suitable sub-configuration among the previously configured sub-configurations.

[0725] As discussed above, the reporting configuration as a whole can thus comprise the configuration of the reporting quantity and the configuration of the uplink channel, e.g. as part of a sub-configuration. According to one variant of the second solution, the reporting configuration can further comprise the configuration of the reference signal. In one example implementation, the reference signal configuration as part of the reporting configuration can be implemented according to the first solution discussed above, i.e. when combining the second and the first solution, the reporting configuration can comprise the reference signal configuration with several candidate resource configurations of the reference signal.

[0726] Alternatively, if the reporting configuration, in particular the sub-configuration, does not comprise the configuration of the reference signal, the reference signal configuration can be configured separately for one or more of the sub-configurations of the reporting configuration, e.g. based on a MAC control element or DCI. In any case, the UE can have access to the necessary configuration information about the reference signal, the reporting quantity and the uplink channel for each reporting configuration, respectively, for each sub-configuration.

[0727] Some variants of the second solution, which can be combined with other variants, relate to how the structure of the reporting configuration and the sub-configuration can be defined. For the sake of explanation, it is exemplarily assumed that the reporting configuration comprises the configuration of the reporting quantity, the configuration of the uplink channel and the configuration of the reference signal (see discussion above).

[0728] In one implementation, the uplink channel transmission configuration can be configured for each sub-configuration, or shared for at least two sub-configurations or for all sub-configurations. Figure 16 The different possibilities described above are illustrated. In Figure 16 Part A of, each sub-configuration comprises its own uplink channel configuration. This allows for maximum flexibility of the configuration of the uplink channel in the sub-configuration, as for each sub-configuration, a different uplink channel configuration can be defined (although it is not mandatory). This allows the base station to control the aspects of the measurement report of the UE.

[0729] In Figure 16 Part C of, there is only one uplink channel configuration in the reporting configuration, which is shared by all sub-configurations of this reporting configuration. Although this implementation limits the flexibility, it reduces the control overhead for configuring the reporting configuration (e.g. in RRC) and can also result in a smaller impact on the standard specification.

[0730] In Figure 16 Part B of, two sub-configurations share the same uplink channel configuration, while another sub-configuration comprises its own uplink channel configuration. This implementation represents a compromise between the two implementations of Figure 16 Parts A and C of.

[0731] According to Figure 16Depending on parts A to C of the above, the UE can be able to support three different possible structures of reporting configuration and sub-configuration. The base station can decide how to best structure the reporting configuration, which in turn increases the flexibility of the configuration possibilities on the base station side.

[0732] Furthermore, in a corresponding way as discussed above for the set of reporting quantities, the set of reference signals can be configured per sub-configuration, or shared for at least two sub-configurations, or shared for all sub-configurations. Figure 17 The different possibilities described above are illustrated. In Figure 17 In part A of the above, each sub-configuration comprises its own set of reporting quantities. This allows for the maximum flexibility of the configuration of reporting quantities between sub-configurations, as for each sub-configuration a different set of reporting quantities can be defined (although it is not mandatory).

[0733] In part B of the above, two sub-configurations share the same set of reporting quantities, while another sub-configuration comprises its own set of reporting quantities. This implementation represents a compromise between the two implementations of parts A and C of the above. Figure 17 In part C of the above, there is only one set of reporting quantities in the reporting configuration, shared by all sub-configurations of this reporting configuration. Although this implementation limits the flexibility, it reduces the control overhead for configuring the reporting configuration (e.g. in RRC), and can also result in a smaller impact on the standard specification.

[0734] Figure 17 In part B of the above, two sub-configurations share the same set of reporting quantities, while another sub-configuration comprises its own set of reporting quantities. This implementation represents a compromise between the two implementations of parts A and C of the above. Figure 17 According to parts A to C of the above, the UE can be able to support three different possible structures of reporting configuration and sub-configuration. The base station can decide how to best structure the reporting configuration, which in turn increases the flexibility of the configuration possibilities on the base station side.

[0735] Figure 17 Furthermore, in a corresponding way as discussed above for the set of reporting quantities, the set of reference signals can be configured per sub-configuration, or shared for at least two sub-configurations, or shared for all sub-configurations.

[0736] The different possibilities described above are illustrated. In Figure 18 In part A of the above, each sub-configuration comprises its own set of reporting quantities. This allows for the maximum flexibility of the configuration of reporting quantities between sub-configurations, as for each sub-configuration a different set of reporting quantities can be defined (although it is not mandatory). Figure 18 In part B of the above, two sub-configurations share the same set of reporting quantities, while another sub-configuration comprises its own set of reporting quantities. This implementation represents a compromise between the two implementations of parts A and C of the above.

[0737] Figure 18 ​​​In part C of the solution, there is only one configuration of reference signals in the reporting configuration that is shared by all sub-configurations of the reporting configuration. Although this embodiment limits flexibility, it reduces control overhead (e.g. in RRC) for configuring the reporting configuration and can also result in less impact on standard specifications.

[0738] In Figure 18 In part B of the solution, two sub-configurations share the same reference signal configuration, while another sub-configuration comprises its own reference signal configuration. This embodiment represents Figure 18 a compromise between the two embodiments of parts A and C of the solution.

[0739] According to Figure 17 parts A to C of the solution, the UE can be able to support three different possible structures of reporting configurations and sub-configurations. The base station can decide how to best structure the reporting configuration, which in turn thus increases the flexibility of the configuration possibilities on the base station side.

[0740] According to a second solution, the base station, after having pre-configured the reporting configuration and the sub-configurations, then selects which one (and thus which reporting configurations) of the sub-configurations should be used by the UE for reference signal measurements and measurement result reporting. Accordingly, a reporting indication is transmitted by the base station to the UE to indicate the selected sub-configuration(s).

[0741] According to further variants of the second solution, which can be combined with any other variant described herein, there are several ways on how to implement the reporting indication.

[0742] In one possible embodiment, the reporting indication indicates one or more sub-configurations based on group IDs. In particular, each of the plurality of sub-configurations is associated with one of a plurality of group IDs, such that there is an explicit one-to-one relationship between the group IDs and the one or more sub-configurations. Moreover, it is exemplarily assumed that one sub-configuration can only belong to one group.

[0743] The association between the group IDs and the sub-configurations can be pre-configured between the base station and the UE, e.g. using RRC messages.

[0744] In another possible embodiment, the reporting indication indicates one or more sub-configurations based on a bitmap. Each bit of the bitmap can be associated with one or more of the plurality of sub-configurations. Accordingly, a bit of the bitmap indicates that the measurement reporting signal should be based on the associated one or more sub-configurations by setting the bit to a certain value, such as 1.

[0745] The association between the bits of the bitmap and the sub-configurations can be pre-configured between the base station and the UE, e.g. using RRC messages.

[0746] In another implementation, the reporting indication indicates one or more sub- configurations based on a code word. In particular, each code word can be associated with one or more of a plurality of sub-configurations. In one example, one sub-configuration can be associated with more than one code word, such that the code word based implementation is flexible in defining different combinations of sub-configurations to be indicated by the base station.

[0747] The association between code words and sub-configurations can be configured in advance between the base station and the UE, e.g. using RRC messages.

[0748] Another implementation regarding how to indicate the sub-configuration is based on indicating the first N or the last N of all pre-configured sub-configurations. In more detail, it can be exemplarily assumed that the sub-configurations are configured by the base station such that the relevance and importance of the base station’s configured sub-configurations increases with the order. Accordingly, the base station simply indicates the number N, and the UE performs the measurement and reporting based on the number N of sub-configurations in the order as indicated. Such an implementation helps to reduce the bits needed for the reporting indication.

[0749] In other exemplary implementations, the reporting indication is received by the UE as a radio resource control, RRC, message or a medium access control, MAC, control element or a downlink control information, DCI, message. For example, when using a MAC CE or a DCI message, the measurement process and reporting can be quickly and easily adapted by the base station to its needs.

[0750] Further, in exemplary implementations, the reporting configuration with multiple sub-configurations is received by the UE as a radio resource control, RRC, message.

[0751] In the foregoing, it was described how the UE is configured to perform the measurement and measurement reporting taking into account the indicated sub-configuration. The second solution and its various variants and implementations can be applied to scenarios where the generation and transmission of the measurement report is performed by the UE periodically, semi-persistently or aperiodically.

[0752] According to 5G compliant exemplary implementations, the second solution reuses at least a part of the configuration structures for measurement and measurement reporting already defined in the 3GPP standards, e.g. as described above. According to one exemplary assumption, the above-mentioned reference signal can be a CSI-RS (channel state information reference signal). Further, the reporting configuration can be implemented the same or similar as the RRC information element CSI-ReportConfig described above with respect to TS 38.331.

[0753] Third solution - CSI priority determination rule

[0754] In short, the third solution aims at defining improved priority determination rules for prioritizing measurement results for scenarios in which measurement results are generated based on sub-configurations within a reporting configuration (e.g., the sub-configurations of the second solution).

[0755] Correspondingly, it is exemplarily assumed that the reporting configuration is structured with a plurality of sub-configurations. In one example, the third solution can be used in combination with the second solution, thereby providing an improved measurement and reporting procedure on how to configure the reporting of measurement results using sub-configurations within a reporting configuration. Moreover, as mentioned above, the second solution can be combined with the first solution, so that a combination of the first, second, and third solution is also possible.

[0756] On the other hand, the third solution can also be independent, i.e., not combined with any of the first and second solutions.

[0757] An exemplary procedure according to the third solution, as will be disclosed in further more detail below, is implemented by a UE comprising the following. A processor of the UE determines a priority of a measurement result to be transmitted to a base station. The priority of the measurement result depends on a priority determination rule, which is based on one or more of:

[0758] • a measurement result determined based on a reporting configuration with a plurality of sub-configurations has a higher or lower priority than a measurement result determined based on a reporting configuration without a plurality of sub-configurations,

[0759] • a number of sub-configurations of the reporting configuration, optionally wherein the more the number of sub-configurations of the reporting configuration, the higher or lower the priority of the measurement result determined based on the reporting configuration, and

[0760] • the lower an index associated with a sub-configuration of the reporting configuration, the higher or lower the priority of the measurement result determined based on the sub-configuration.

[0761] A corresponding exemplary method according to the third solution comprises the following steps performed by a UE:

[0762] determining a priority of a measurement result to be transmitted to a base station, wherein the priority of the measurement result depends on a priority determination rule, which is based on one or more of:

[0763] • a measurement result determined based on a reporting configuration with a plurality of sub-configurations has a higher or lower priority than a measurement result determined based on a reporting configuration without a plurality of sub-configurations,

[0764] • a number of sub-configurations of the reporting configuration, optionally wherein the more the number of sub-configurations of the reporting configuration, the higher or lower the priority of the measurement result determined based on the reporting configuration, and

[0765] • the lower the index associated with a sub-configuration of a reporting configuration, the higher or lower the priority of a measurement result determined based on the sub-configuration.

[0766] Figure 19 A corresponding sequence diagram illustrating exemplary UE behavior in line with the above UE and UE method according to the third solution is shown in Fig. 7. As from Figure 19 It is further apparent that, although the third solution focuses on how to determine the priority of measurement results, the third solution can have other aspects. For example, the UE can receive the necessary configuration information for being able to perform measurements and measurement reporting. This can involve the UE receiving a reporting configuration from the base station with a plurality of sub-configurations therein. Accordingly, the UE performs measurements on reference signals in accordance with the received configuration(s). The measurement results thus achieved can then be subject to the improved priority determination of the third solution, which takes into account the presence of sub-configurations if needed, as presented above and explained in detail below. Furthermore, the priority of the measurement results thus determined can then be used subsequently, e.g. when generating one or more measurement reports with the measurement results. Finally, the measurement reports thus generated are transmitted by the UE to the base station.

[0767] The third solution also provides for an improved base station, which can comprise the following.

[0768] The processor of the base station generates a reporting configuration, the reporting configuration comprising a plurality of sub-configurations. The transmitter of the base station then transmits the generated reporting configuration to the UE. The receiver of the base station receives one or more measurement reports from the UE, the measurement reports being generated by the UE based on applying a priority determination rule. In one example, the priority determination rule can be defined and controlled by the base station so as to be based on one or more of:

[0769] • measurement results determined based on a reporting configuration with a plurality of sub-configurations have a higher or lower priority than measurement results determined based on a reporting configuration without a plurality of sub-configurations,

[0770] • the number of sub-configurations of a reporting configuration, optionally wherein the more the number of sub-configurations of a reporting configuration, the higher or lower the priority of measurement results determined based on the reporting configuration, and

[0771] • the lower the index associated with a sub-configuration of a reporting configuration, the higher or lower the priority of a measurement result determined based on the sub-configuration.

[0772] Accordingly, the third solution allows to adapt existing priority determinations also to those scenarios in which the reporting configuration comprises multiple sub-configurations. In more detail, 5G NR already provides mechanisms for handling CSI reporting, wherein these mechanisms can use the priority of a CSI report (and the measurement results contained therein).

[0773] For example, TS 38.214 provides in clause 5.2.5 priority rules that can be applied to two overlapping PUSCHs, and for example, handles the case of two CSI report collisions (if the time occupancy of the physical channels scheduled to carry the two CSI reports overlap in at least one OFDM symbol and are transmitted on the same carrier). For such colliding CSI reports, 5G NR provides the possibility that the CSI report with the higher priority value should not be transmitted by the UE.

[0774] Furthermore, clause 9.2.5.2 of TS 38.213 also defines a mechanism to select a CSI report based on the priority value of the CSI report. The not selected CSI report can need to be discarded by the UE and, thus, not transmitted to the base station.

[0775] Moreover, according to clause 6.3.1.1 of TS 38.212, the transmission of uplink control information (such as CSI reports, HARQ ACK / NACK, scheduling requests) involves UCI bit sequence generation, which can also be based on priority.

[0776] In summary, the priority of channel state measurements is used in various mechanisms at the UE. More generally, the related mechanisms can include, for example:

[0777] • the bit sequence generation of uplink control information carrying measurement results, wherein the priority of the measurement results is taken into account for determining the order of the bits generated by the bit sequence generation;

[0778] • the discarding of measurement results, which involves discarding measurement results according to their priority (e.g., in increasing order of priority).

[0779] Accordingly, when implementing the new feature of sub-configurations as part of a reporting configuration, the inventors have identified the possibility to adapt such existing mechanisms to the new feature. In particular, the third solution provides improved priority determination rules that take sub-configurations into account.

[0780] Exemplarily, assume that a UE is configured by a base station for measurements and reporting, which also involves that the UE is configured with a reporting configuration comprising multiple sub-configurations. Accordingly, the UE performs measurements on reference signals and, thus, generates measurement results. At this point, the UE can determine the priority of the measurement results to be transmitted to the base station based on the improved priority determination concept.

[0781] This improved priority determination takes sub-configurations into account and can follow one or more rules discussed below.

[0782] According to one rule, a measurement result determined based on a reporting configuration with multiple sub-configurations has a higher or lower priority than a measurement result determined based on a reporting configuration without multiple sub-configurations. This new rule is thus advantageous as it allows the UE to compare measurement results generated based on the new sub-configuration feature with legacy configuration structures without sub-configurations.

[0783] According to another rule, the number of sub-configurations of a reporting configuration has an impact on the priority of the measurement results thus generated. In one example, the more the number of sub-configurations of a reporting configuration, the higher or lower the priority of the measurement results determined based on this reporting configuration. This new rule is thus advantageous as it allows the UE to prioritize reporting configurations with new sub-configuration structures among them.

[0784] According to another rule, the lower the index associated with a sub-configuration of a reporting configuration, the higher or lower the priority of the measurement results determined based on this sub-configuration. In other words, the sub-configurations are in increasing or decreasing order of priority within the reporting configuration. This new rule is thus advantageous as it allows the UE to apply a priority ordering within one reporting configuration.

[0785] As mentioned above, the new rules allow a very flexible priority ordering from the base station side, e.g. allowing the base station to define higher or lower priorities according to its needs. For example, the base station can assign a higher priority to a reporting configuration with many sub-configurations (compared to a reporting configuration with only a few sub-configurations) as the base station aims at obtaining as much information as possible. On the other hand, the base station can assign a lower priority to a reporting configuration with a large number of sub-configurations (compared to a reporting configuration with only a few sub-configurations) as the base station aims at reducing the uplink control overhead.

[0786] Similarly, the base station can assign a higher priority to a reporting configuration without sub-configurations (compared to a reporting configuration with sub-configurations) as the base station considers the benefits provided by sub-configurations as optional and thus wants to mainly support legacy operation for measurement reporting. On the other hand, the base station can assign a lower priority to a reporting configuration without sub-configurations (compared to a reporting configuration with sub-configurations) as the base station aims at obtaining as much information as possible in order to facilitate energy saving (at the UE and / or the base station) by adapting measurement and reporting configurations based on the different measurement results obtained.

[0787] According to a further variant of the third solution, which can be combined with other variants, the improved priority determination described above can also take into account the presence of certain measurement results as will be described below. In particular, the priority determination can be based on a further optional rule according to which the higher the rank indicated by the rank indicator of a measurement result, the higher or lower the priority of the measurement result (or of the entire measurement report comprising the rank indicator). In more detail, the rank indicator allows to obtain information about how well the antenna pattern used by the base station performs, wherein a high rank indicator value indicates a good performance, while a low rank indicator value indicates a poor performance.

[0788] According to a further optional rule, the higher the channel quality indicated by the channel quality indicator of a measurement result, the higher or lower the priority of the measurement result (or of the entire measurement report comprising the channel quality indicator).

[0789] Likewise, these rules based on the rank indicator and the channel quality information allow for a very flexible prioritization from the base station side, e.g. allowing the base station to define higher or lower priorities according to its needs. For example, knowing a low rank indicator value or low channel quality information can be very useful for the base station, as it indicates that there is a need to adapt the transmission parameters at the base station side. Based on such an intention, a priority determination rule can be used, wherein a low rank indicator value or low channel quality information leads to a high priority of the corresponding measurement result.

[0790] On the other hand, knowing a high rank indicator value or high channel quality information is useful for the base station, as it indicates that a high throughput is possible, so that the base station can adapt the amount of data to be transmitted in the downlink. Based on such an intention, a priority determination rule can be used, wherein a high rank indicator value or high channel quality information leads to a high priority of the corresponding measurement result.

[0791] According to a further variant of the third solution, which can be combined with other variants, the improved priority determination described above can be based on additional rules, e.g. any existing prioritization rules. For example, according to a further rule, the lower the index associated with a reporting configuration (e.g. the CSI-ReportConfig ID in 5G NR), the higher (alternatively, the lower) the priority of the measurement result determined based on the reporting configuration.

[0792] According to an exemplary implementation compatible with 5G, the third solution reuses at least part of the configuration structures for measurements and measurement reports already defined in the 3GPP standards, e.g. as described above. According to one exemplary assumption, the above-mentioned reference signals can be CSI-RS (Channel State Information Reference Signals).

[0793] Fourth solution - CSI dropping

[0794] In short, the fourth solution targets defining improved dropping rules for not transmitting measurement results for scenarios where measurement results are generated based on different transmission characteristics of reference signals (e.g., measurement results are generated based on candidate resource configurations of reference signals of the first solution) and / or for scenarios where measurement results are generated based on sub-configurations within a reporting configuration (e.g., sub-configurations of the second solution).

[0795] Accordingly, the fourth solution is mainly applied in such scenarios as described above. Exemplarily, it is assumed that a UE can be configured with multiple candidate resource configurations for configuring reference signals (see also candidate transmission characteristics of reference signals). In one example, the fourth solution can be used in combination with the first solution.

[0796] Additionally or alternatively, it is exemplarily assumed that a reporting configuration is structured with multiple sub-configurations. In one example, the fourth solution can be used in combination with the second solution, thereby providing an improved measurement and reporting procedure on how to configure reporting of measurement results using sub-configurations within a reporting configuration.

[0797] Further, the improved dropping rules can be based in part on priorities of measurements, such as priorities defined according to the third solution.

[0798] On the other hand, the fourth solution can also be standalone, i.e., not combined with any of the first, second, or third solution.

[0799] For example, the improved dropping procedure of the fourth solution can be applied to a measurement report with multiple measurement results generated from multiple candidate resource configurations of reference signals or from multiple sub-configurations of a reporting configuration. Similarly, the improved dropping procedure of the fourth solution can be applied to multiple measurement reports conflicting with each other (where one or more have multiple measurement results generated from multiple candidate resource configurations of reference signals or from multiple sub-configurations of a reporting configuration) (e.g., where a conflict can be understood as two conflicting measurement reports conflicting in at least one OFDM symbol and would be transmitted on the same carrier).

[0800] One exemplary procedure according to the fourth solution as will be disclosed in further more detail below is implemented by a UE comprising the following. It is assumed that multiple measurement results are to be transmitted to a base station. At least one of the measurement results is determined based on one of multiple sub-configurations of a reporting configuration or based on one of multiple candidate resource configurations of reference signals.

[0801] The processor of the UE determines, based on a dropping rule, whether to not transmit one or more of the multiple measurement results, wherein the dropping rule is based on one or more of:

[0802] • discard measurement results with low priority,

[0803] • do not discard measurement results with rank indicators indicating a rank higher or lower than a rank threshold,

[0804] • do not discard measurement results with channel quality indicators indicating a channel quality higher or lower than a channel quality threshold,

[0805] • measurement results are selected for transmission in decreasing order of priority until a capacity upper limit for uplink channel resources carrying measurement results is reached, wherein remaining unselected measurement results are discarded, optionally wherein the capacity upper limit is determined by the UE based on an amount of available resources in the uplink channel or based on an indication received from the base station via one or more of a radio resource control, RRC, message, a medium access control, MAC, control element, or a downlink control information, DCI, message,

[0806] • measurement results are selected for transmission in decreasing order of priority until a processing upper limit for the UE for processing measurement results is reached, wherein remaining unselected measurement results are discarded, optionally wherein the processing upper limit is determined by the UE based on an indication received from the base station via one or more of a radio resource control, RRC, message, a medium access control, MAC, control element, or a downlink control information, DCI, message, and

[0807] • a number N of measurement results out of the plurality of measurement results, optionally wherein measurement results generated based on a first N sub-configurations or a last N sub-configurations are discarded, optionally wherein a first N measurement results with highest or lowest rank indicators are discarded, optionally wherein a first N measurement results with highest or lowest channel quality indicators are discarded, optionally wherein the number N is determined by the UE from a medium access control, MAC, control element or a downlink control information, DCI, message.

[0808] A corresponding example method according to the fourth solution comprises the following steps performed by the UE. A plurality of measurement results are assumed to be transmitted to the base station. At least one of the measurement results is determined based on a reporting configuration with a plurality of sub-configurations or based on one of a plurality of candidate resource configurations of a reference signal. The steps comprise:

[0809] determining whether to not transmit one or more of the plurality of measurement results based on a discard rule, wherein the discard rule is based on one or more of:

[0810] • discard measurement results with low priority,

[0811] • do not discard measurement results with rank indicators indicating a rank higher or lower than a rank threshold,

[0812] • not discarding measurement results with a channel quality indicator indicating a channel quality higher or lower than a channel quality threshold,

[0813] • measurement results are selected for transmission in decreasing order of priority until a capacity upper limit for uplink channel resources carrying measurement results is reached, wherein remaining unselected measurement results are discarded, optionally wherein the capacity upper limit is determined by the UE based on an amount of available resources in the uplink channel or based on an indication received from the base station via one or more of a radio resource control, RRC, message, a medium access control, MAC, control element, or a downlink control information, DCI, message,

[0814] • measurement results are selected for transmission in decreasing order of priority until a processing upper limit for the UE for processing measurement results is reached, wherein remaining unselected measurement results are discarded, optionally wherein the processing upper limit is determined by the UE based on an indication received from the base station via one or more of a radio resource control, RRC, message, a medium access control, MAC, control element, or a downlink control information, DCI, message, and

[0815] • a number N of measurement results out of the plurality of measurement results, optionally wherein measurement results generated based on a first N sub-configurations or a last N sub-configurations are discarded, optionally wherein a first N measurement results with a highest or lowest rank indicator are discarded, optionally wherein a first N measurement results with a highest or lowest channel quality indicator are discarded, optionally wherein the number N is determined by the UE from a medium access control, MAC, control element or a downlink control information, DCI, message.

[0816] Figure 20 A corresponding sequence diagram illustrating exemplary UE behavior consistent with the above-described UE and UE method according to the fourth solution is shown in FIG. 12. As from Figure 20 It is further apparent that although the fourth solution focuses on how to discard measurement results from transmission, there can be other aspects of the fourth solution. For example, the UE can receive necessary configuration information for being able to perform measurements and measurement reporting. This can involve the UE receiving a reporting configuration from the base station with a plurality of sub-configurations, and / or the UE receiving a reference signal configuration from the base station with a plurality of candidate resource configurations of a reference signal. Accordingly, the UE performs measurements on the reference signal according to the received configuration(s). The measurement results thus achieved can then be subject to the improved discarding mechanism of the fourth solution, as presented above and explained in detail below. Furthermore, the UE can generate one or more measurement reports with the measurement results thus not discarded. Finally, the measurement reports thus generated are transmitted by the UE to the base station.

[0817] The fourth solution also provides for an improved base station, which can comprise the following.

[0818] The processor of the base station generates a reporting configuration, the reporting configuration comprising a plurality of sub-configurations. Additionally or alternatively, the processor can generate a reference signal configuration with a plurality of candidate resource configurations of reference signals that can be transmitted by the base station to the UE. The transmitter of the base station then transmits the generated reporting configuration and the generated reference signal configuration to the UE. The receiver of the base station receives one or more measurement reports from the UE, the measurement reports being generated by the UE after having applied, if necessary, a dropping mechanism following a dropping rule. In one example, the dropping rule can be defined and controlled by the base station in order to be based on one or more of:

[0819] • dropping measurement results with a low priority,

[0820] • not dropping measurement results with a rank indicator indicating a rank higher or lower than a rank threshold,

[0821] • not dropping measurement results with a channel quality indicator indicating a channel quality higher or lower than a channel quality threshold,

[0822] • measurement results are selected for transmission in a decreasing order of priority until a capacity upper limit of uplink channel resources for carrying the measurement results is reached, wherein the remaining unselected measurement results are dropped, optionally wherein the capacity upper limit is determined by the UE based on an amount of available resources in the uplink channel or based on an indication received from the base station via one or more of a radio resource control, RRC, message, a medium access control, MAC, control element or a downlink control information, DCI, message,

[0823] • measurement results are selected for transmission in a decreasing order of priority until a processing upper limit of the UE for processing the measurement results is reached, wherein the remaining unselected measurement results are dropped, optionally wherein the processing upper limit is determined by the UE based on an indication received from the base station via one or more of a radio resource control, RRC, message, a medium access control, MAC, control element or a downlink control information, DCI, message, and

[0824] • a number N of measurement results out of the plurality of measurement results, optionally wherein the first N measurement results or the last N measurement results generated based on the sub-configurations are dropped, optionally wherein the first N measurement results with the highest or lowest rank indicator are dropped, optionally wherein the first N measurement results with the highest or lowest channel quality indicator are dropped, optionally wherein the number N is determined by the UE from a medium access control, MAC, control element or a downlink control information, DCI, message.

[0825] Accordingly, the fourth solution also allows to adapt the existing CSI discarding procedures to those scenarios in which the measurement results are generated based on different transmission characteristics of the reference signals (e.g., based on the candidate resource configuration of the reference signals of the first solution) and / or scenarios in which the measurement results are generated based on sub-configurations within the reporting configuration (e.g., the sub-configuration of the second solution). In more detail, 5G NR already provides mechanisms for discarding or reducing CSI reports.

[0826] In more detail, the technical standard TS 38.214 defines CSI reporting using PUSCH and PUCCH in clauses 5.2.3 and 5.2.4, respectively, which can lead to discarding or reducing of measurement results. Clause 5.2.1.6 of TS 38.214 further defines CSI process criteria, providing a limitation on the processing of CSI reports by the UE. Furthermore, clause 6.3.1.1.2 of TS 38.212 also provides details on CSI reporting.

[0827] In summary, discarding or reducing of measurement results is used by the UE in various mechanisms and can be improved according to the fourth solution. Accordingly, the inventors have identified the possibility to adapt such existing mechanisms to new scenarios.

[0828] The discarding concept according to the fourth solution will be discussed in more detail below.

[0829] According to one possible discarding rule, discarding can be based on a priority determined for the measurement results. According to one exemplary implementation, the priority can be determined according to the third solution. On the other hand, the priority of the measurement results can also be determined differently than according to the third solution.

[0830] Another possible discarding rule is based on a rank indicator that can be included in the measurement report. A rank indicator threshold can be defined and the rank indicator of the measurement results is then compared to the rank indicator threshold. Depending on the intention of the measurement report, rank indicators above or below the rank threshold will not be discarded by the UE. As already discussed for the third solution, both high rank indicator values and low rank indicator values can be of particular interest for the base station, and should therefore not be discarded if possible. The discarding rule can be adjusted and configured accordingly to accommodate the needs of the base station.

[0831] Another possible discard rule is based on a channel quality indicator indicating the channel quality. A channel quality threshold can be defined and the channel quality indicator of the measurement result is then compared to the channel quality threshold. Depending on the intention of the measurement report, the UE does not discard the channel quality indicator being above or below the channel quality threshold. As already discussed for the third solution, both high and low channel quality indications can be of particular interest for the base station and should therefore not be discarded, if possible. The discard rule can be adjusted and configured accordingly to accommodate the needs of the base station.

[0832] Another possible discard rule takes into account the capacity of the uplink channel resources used to carry the measurement results to the base station. In particular, an upper limit of the capacity of the uplink channel resources can be determined or configured. The capacity upper limit can be determined by the UE, for example, based on the amount of available resources in the uplink channel. Additionally or alternatively, the capacity upper limit can be indicated by the base station, for example, via a RRC message, a MAC CE or a DCI message. In any case, such a capacity upper limit has been defined and should be taken into account. Thus, when the measurement results to be transmitted would exceed the capacity upper limit, the UE has to perform a discard or reduction. To this end, the UE selects as many measurement results as possible until the capacity upper limit of the uplink channel resources as defined is reached. Any other measurement result cannot be transmitted and is thus discarded by the UE. According to one example, the measurement results can be selected in a decreasing order of priority, although a different selection order is equally possible.

[0833] Another possible discard rule takes into account the processing limit of the UE used to process the measurement results. In particular, an upper limit of the UE processing capacity can be determined by the UE, for example, based on its own capabilities. Additionally or alternatively, the processing upper limit can be indicated by the base station, for example, via a RRC message, a MAC CE or a DCI message. In any case, such a processing upper limit has been defined and should be taken into account. Each measurement result and measurement report can be associated with a processing occupation and the sum of the calculated processing occupations should not exceed the processing upper limit. In case the processing upper limit is exceeded, the UE has to perform a discard or reduction. To this end, the UE selects as many measurement results as possible until the sum of the occupation values of the selected measurement results reaches the defined processing upper limit. Any other measurement result cannot be transmitted and is thus discarded by the UE. According to one example, the measurement results can be selected in a decreasing order of priority, although a different selection order is equally possible.

[0834] The two preceding discard rules make use of the priority of the measurement results during the selection. According to an example implementation thereof, the priority can be determined according to the third solution discussed above, although different priority determinations are equally possible (e.g., according to the current definition in TS 38.214, section 5.2.5).

[0835] According to another discarding rule, the UE simply selects N measurement results among all available measurement results. For example, the first or last N measurements in a sequence order can be selected for transmission, while the UE can discard the remaining measurement results if necessary. The sequence order can for example follow the rank indicator values, resulting for example in discarding the first N with the highest or lowest rank indicator values. Another possibility for the sequence order can be to follow the indices of the sub- configurations based on which the measurement results were generated. This can result for example in discarding the first N with the lowest or highest indices of the associated sub- configurations. Another possibility for the sequence order can be to follow the channel quality indicator values, resulting for example in discarding the first N with the highest or lowest channel quality indicator values. The number N can be determined by the UE for example according to an indication transmitted by the base station in a MAC CE or DCI message.

[0836] According to a fourth solution, an improved discarding procedure is used as part of the measurement and measurement reporting procedure and can be applied if necessary. Some scenarios in which the discarding procedure should be applied have already been mentioned above, for example in connection with the uplink channel capacity upper limit and the measurement processing upper limit. The improved discarding can also be applied in the following cases.

[0837] Generally, discarding can become necessary if the UE is not able to transmit all available measurement results to the base station in a particular reporting period. A more detailed example involves the case where two or more measurement results collide with each other in the time domain.

[0838] The measurement results selected for transmission are multiplexed and then transmitted.

[0839] A further variant of the fourth solution, which can be combined with other variants, takes into account the fact that some formats for transmitting measurement results are based on splitting the measurement results into two parts. According to one example, the first part can have a fixed bit size, include some measurement results, and further identify the number of bits of the second part with the remaining measurement results. There are several possibilities how the UE can apply the improved discarding procedure to such two-part format for reporting measurement results. One possibility is to perform discarding for both the first part and the second part of the measurement results, such that it is discarded as a whole or selected for transmission. Another possibility is to perform discarding only for one of the two parts, for example for the first part of the measurement results but not for the second part, or for the second part of the measurement results but not for the first part.

[0840] According to an example 5G-compliant implementation, there are already two-part CSI reporting formats, e.g. CSI part 1 and CSI part 2 known from TS 38.212 clause 6.3.1.1.2 and TS 38.214 clauses 5.2.3 and 5.2.4. It is apparent from there that CSI part 1 has a fixed payload size, includes some CSI and identifies the number of information bits of CSI part 2, which in turn includes further CSI.

[0841] According to a further variant of the fourth solution, which can be combined with other variants, the UE is able to indicate its capabilities to the base station. This has the advantage that the base station can take the UE capabilities into account to more appropriately configure the UE measurements and reporting. The UE capability indication can indicate one or more of the following.

[0842] One possible indication is the maximum number of reporting configurations the UE should be configured with. Additionally or alternatively, the UE capability indication can indicate the maximum number of reporting configurations the UE should be configured with in multiple sub-configurations. Another possible indication is the maximum number of sub-configurations within a reporting configuration the UE should be configured with. Another indication can be the maximum total number of sub-configurations across all reporting configurations.

[0843] The UE can determine the respective maximum parameters on its own. In one example implementation, the UE can apply a scaling factor between 0 and 1 when determining some of the above-mentioned maximum parameters. In one example, the sub-configurations can be counted in the same way as the reporting configurations. On the other hand, the sub-configurations can not be counted by the UE at all, but should only contribute partially to the maximum parameters, i.e. should be scaled in an appropriate way, e.g. with a scaling factor of 0.5.

[0844] According to an example 5G-compliant implementation, the fourth solution reuses at least part of the configuration structures for measurements and measurement reporting already defined in 3GPP standards, e.g. as described above. According to one example assumption, the above-mentioned reference signals can be CSI-RS (Channel State Information Reference Signals).

[0845] Further aspects

[0846] According to a first aspect, a UE is provided comprising the following. A receiver receives, from a base station, a reference signal configuration regarding a plurality of candidate resource configurations of reference signals that can be transmitted by the base station to the UE. The receiver receives, from the base station, a reference signal configuration indication indicating one or more candidate resource configurations of the plurality of candidate resource configurations configured. A processor measures, based on the indicated candidate resource configurations, the reference signals received from the base station. The processor generates one or more measurement reports comprising measurement results of the measured reference signals. A transmitter transmits, to the base station, the generated measurement reports.

[0847] According to a second aspect provided in addition to the first aspect, at least two of the plurality of candidate resource configurations differ from each other by defining a candidate transmission characteristic for the reference signal having a different value, wherein the different candidate transmission characteristics are one or more of:

[0848] • a different antenna port pattern for the reference signal,

[0849] • a different transmission power for the reference signal, and

[0850] • a different transmission power for a downlink data channel for which the reference signal is measured.

[0851] In an optional implementation, the plurality of candidate resource configurations further define radio resource elements in the frequency and time domain for carrying the reference signal.

[0852] According to a third aspect provided in addition to the second aspect, the antenna port pattern for the reference signal is defined by the candidate resource configuration based on one or more of:

[0853] • a code division multiplexing, CDM, group index,

[0854] • an index of an antenna port, and

[0855] • a combination of the CDM group index and the antenna port index.

[0856] In an optional implementation, the transmission power of the downlink data channel is defined based on a power offset with respect to the reference signal. In another optional implementation, the transmission power for the reference signal is defined based on a power offset with respect to a synchronization signal block transmission from the base station.

[0857] According to a fourth aspect provided in addition to any of the first to third aspects, at least one of the plurality of candidate resource configurations is defined such that at least one transmission characteristic defined by the at least one candidate resource configuration is different from a transmission characteristic actually used by the base station. In an optional implementation, the different transmission characteristic refers to one or more of:

[0858] • a different antenna port pattern, e.g., a subset of all antenna ports actually used by the base station for transmitting the reference signal, and

[0859] • a different transmission power, e.g., a transmission power that is lower or higher than a transmission power actually used by the base station for transmitting the reference signal,

[0860] • a different transmission power, e.g., a transmission power that is lower or higher than a transmission power actually used by the base station for transmitting the downlink data channel.

[0861] According to a fifth aspect provided in addition to any of the first to fourth aspects, the reference signal configuration configures one or more radio resources for the reference signal, wherein at least one radio resource is defined with two or more different candidate transmission properties for the reference signal. In an optional implementation, the reference signal configuration configures one or more radio resource sets for the reference signal, wherein each radio resource set indicates one or more radio resources for the reference signal.

[0862] According to a sixth aspect provided in addition to any of the first to fifth aspects, the reference signal configuration indicates one or more candidate resource configurations based on one or more of:

[0863] • a group ID, wherein each of the plurality of candidate resource configurations is associated with one of a plurality of group IDs,

[0864] • a bitmap, wherein each bit of the bitmap is associated with one or more of the plurality of candidate resource configurations, and one value of the bits of the bitmap indicates that the measurement of the reference signal should be based on the associated one or more candidate resource configurations, and

[0865] • a code word, wherein each code word is associated with one or more of the plurality of candidate resource configurations.

[0866] In an optional implementation, the reference signal configuration is received by the UE as a radio resource control, RRC, message or a medium access control, MAC, control element or a downlink control information, DCI, message. In another optional implementation, the reference signal configuration is received by the UE as a radio resource control, RRC, message. In another optional implementation, the generation and transmission of the measurement report is performed by the UE periodically, semi-persistently or aperiodically.

[0867] According to a seventh aspect provided in addition to any of the first to sixth aspects, the receiver receives from the base station a reporting configuration, the reporting configuration comprising a plurality of sub-configurations, each of the plurality of sub-configurations configuring one or more of:

[0868] • a set of measurement reporting quantities, such as one or more of a channel quality parameter, a channel quality indicator, a precoding matrix indicator, a reference signal indicator, a layer indicator, a rank indicator,

[0869] • an uplink channel transmission configuration, the uplink channel transmission configuration configuring one or more of a time and a frequency of a radio resource for an uplink channel, the uplink channel transmission configuration being used for transmitting a measurement result for the respective sub-configuration.

[0870] The receiver receives a reporting indication indicating one or more sub-configurations. Based on the indicated one or more sub-configurations, the processor generates a measurement report and the transmitter transmits the measurement report.

[0871] According to an eighth aspect provided in addition to the seventh aspect, the sub-configuration further comprises a reference signal configuration defining a reference signal. In an optional implementation, the sub-configuration further comprises a reference signal configuration on one or more candidate resource configurations of reference signals with different transmission characteristics that can be transmitted by the base station to the UE.

[0872] According to a ninth aspect provided in addition to the seventh or eighth aspect, one uplink channel transmission configuration is configured in the following manner:

[0873] - per sub-configuration, or

[0874] - at least two sub-configurations share, or

[0875] - all sub-configurations share,

[0876] Optionally, wherein one set of measurement report quantities is configured in the following manner:

[0877] - per sub-configuration, or

[0878] - for at least two sub-configurations, or

[0879] - for all sub-configurations,

[0880] Optionally, wherein one reference signal configuration is configured in the following manner:

[0881] - per sub-configuration, or

[0882] - for at least two sub-configurations, or

[0883] - for all sub-configurations.

[0884] According to a tenth aspect provided in addition to any of the seventh to ninth aspects, the reporting indication indicates one or more sub-configurations based on one or more of:

[0885] • a group ID, wherein each of the plurality of sub-configurations is associated with one of a plurality of group IDs,

[0886] • a bitmap, wherein each bit of the bitmap is associated with one or more sub-configurations, and one value of the bits of the bitmap indicates that the generation and transmission of the measurement report should be based on the associated sub-configuration, and

[0887] • a code word, wherein each code word is associated with a combination of two or more of the plurality of sub-configurations.

[0888] In an optional implementation, the reporting indication indicates the first N or the last N of the plurality of sub-configurations. In an optional implementation, the reporting indication is received by the UE as a radio resource control (RRC) message or a medium access control (MAC) control element or a downlink control information (DCI) message. In an optional implementation, the reporting configuration is received by the UE as a radio resource control (RRC) message. In an optional implementation, the generation and transmission of the measurement report is performed by the UE periodically, semi-persistently, or aperiodically.

[0889] According to an eleventh aspect provided in addition to any of the first to tenth aspects, the processor determines a priority of the measurement result to be transmitted to the base station. The priority of the measurement result depends on a priority determination rule based on one or more of:

[0890] • the measurement result determined based on a reporting configuration with a plurality of sub-configurations has a higher or lower priority than the measurement result determined based on a reporting configuration without a plurality of sub-configurations,

[0891] • a number of sub-configurations of the reporting configuration, optionally wherein the more the number of sub-configurations of the reporting configuration, the higher or lower the priority of the measurement result determined based on the reporting configuration, and

[0892] • the lower an index associated with a sub-configuration of the reporting configuration, the higher or lower the priority of the measurement result determined based on the sub-configuration.

[0893] According to a twelfth aspect provided in addition to the eleventh aspect, the priority determination rule for determining the priority of the measurement result is further based on one or more of:

[0894] • the higher a rank indicated by a rank indicator of the measurement result, the higher or lower the priority of the measurement result,

[0895] • the higher a channel quality indicated by a channel quality indicator of the measurement result, the higher or lower the priority of the measurement result,

[0896] Optionally, wherein the priority determination rule for determining the priority of the measurement result is further based on one or more of:

[0897] • the lower an index associated with the reporting configuration, the higher or lower the priority of the measurement result determined based on the reporting configuration.

[0898] According to a thirteenth aspect provided in addition to the eleventh or twelfth aspect, the processor takes into account the priority of the measurement result for one or more of:

[0899] • bit sequence generation of uplink control information carrying the measurement results, optionally wherein a priority of the measurement results is taken into account for determining an order of bits generated by the bit sequence generation, and

[0900] • dropping of the measurement results, optionally wherein the measurement results dropping involves dropping the measurement results in an ascending order of the priority.

[0901] According to a fourteenth aspect provided in addition to any of the first to thirteenth aspects, the plurality of measurement results are to be transmitted to the base station. At least one of the measurement results is determined based on a reporting configuration having a plurality of sub-configurations or based on one of a plurality of candidate resource configurations of a reference signal. The processor determines whether to transmit one or more of the plurality of measurement results based on a dropping rule, wherein the dropping rule is based on one or more of:

[0902] • dropping measurement results having a low priority,

[0903] • not dropping measurement results having a rank indicator indicating a rank higher or lower than a rank threshold,

[0904] • not dropping measurement results having a channel quality indicator indicating a channel quality higher or lower than a channel quality threshold,

[0905] • the measurement results are selected for transmission in a decreasing order of the priority until a capacity upper limit of an uplink channel resource for carrying the measurement results is reached, wherein remaining unselected measurement results are dropped, optionally wherein the capacity upper limit is determined by the UE based on an amount of available resources in the uplink channel or based on an indication received from the base station via one or more of a radio resource control, RRC, message, a medium access control, MAC, control element, or a downlink control information, DCI, message,

[0906] • the measurement results are selected for transmission in a decreasing order of the priority until a processing upper limit of the UE for processing the measurement results is reached, wherein remaining unselected measurement results are dropped, optionally wherein the processing upper limit is determined by the UE based on an indication received from the base station via one or more of a radio resource control, RRC, message, a medium access control, MAC, control element, or a downlink control information, DCI, message, and

[0907] • a number N of the plurality of measurement results, optionally wherein measurement results generated based on a first N sub-configurations or a last N sub-configurations are dropped, optionally wherein a first N measurement results having a highest or a lowest rank indicator are dropped, optionally wherein a first N measurement results having a highest or a lowest channel quality indicator are dropped, optionally wherein the number N is determined by the UE from a medium access control, MAC, control element or a downlink control information, DCI, message.

[0908] According to a fifteenth aspect provided in addition to the fourteenth aspect, the dropping rule is applied in one or more of the following cases:

[0909] • in case that all of the plurality of measurement results cannot be transmitted,

[0910] • in case that two or more measurement results collide in time domain,

[0911] • in case that a total capacity for transmitting the plurality of measurement results is greater than an upper limit of a capacity of uplink channel resources for carrying the measurement results, and

[0912] • in case that a total processing for transmitting the plurality of measurement results is greater than an upper limit of a processing for the UE to process the measurement results.

[0913] According to a sixteenth aspect provided in addition to the fourteenth or fifteenth aspect, the measurement results are transmitted in two parts. When the processor applies the dropping rule, the dropping rule is applied by the processor to:

[0914] • both of the first part and the second part of the measurement results, or

[0915] • the first part of the measurement results but not the second part, or

[0916] • the second part of the measurement results but not the first part.

[0917] In optional implementations, the first part has a fixed bit size, includes some measurement results, and further identifies a number of bits of the second part.

[0918] According to a seventeenth aspect provided in addition to any of the fourteenth to sixteenth aspects, the processor generates a UE capability indication, the UE capability indication indicating one or more of:

[0919] • a maximum number of reporting configurations,

[0920] • a maximum number of reporting configurations configured with a plurality of sub-configurations,

[0921] • a maximum number of sub-configurations within a reporting configuration, and

[0922] • a maximum total number of sub-configurations across all reporting configurations.

[0923] In optional implementations, the processor determines one or more of the maximum number of sub-configurations and the maximum total number of sub-configurations based on a scaling factor, wherein the scaling factor is a value between 0 and 1 multiplied for each sub-configuration.

[0924] According to an eighteenth aspect, a base station is provided that includes the following. A processor of the base station generates a reference signal configuration having a plurality of candidate resource configurations of a reference signal that can be transmitted by the base station to a user equipment (UE). A transmitter of the base station transmits the generated reference signal configuration to the UE. The processor determines one or more candidate resource configurations of the plurality of candidate resource configurations of the configuration for use by the UE. The transmitter transmits a reference signal configuration indication to the UE indicating the determined one or more candidate resource configurations. The transmitter transmits the reference signal to the UE. A receiver receives one or more measurement reports from the UE, the measurement reports including measurement results of the reference signal measured by the UE based on the indicated one or more candidate resource configurations.

[0925] According to a nineteenth aspect, a method is provided that includes the following steps performed by a user equipment (UE):

[0926] receiving a reference signal configuration from a base station, the reference signal configuration having a plurality of candidate resource configurations of a reference signal that can be transmitted by the base station to the UE,

[0927] receiving a reference signal configuration indication from the base station, the reference signal configuration indication indicating one or more candidate resource configurations of the plurality of candidate resource configurations of the configuration,

[0928] measuring the reference signal received from the base station based on the indicated candidate resource configuration,

[0929] generating one or more measurement reports, the measurement reports including measurement results for the measured reference signal, and

[0930] transmitting the generated measurement reports to the base station.

[0931] According to a twentieth aspect, a method is provided that includes the following steps performed by a base station:

[0932] generating a reference signal configuration, the reference signal configuration having a plurality of candidate resource configurations of a reference signal that can be transmitted by the base station to a user equipment (UE),

[0933] transmitting the generated reference signal configuration to the UE,

[0934] determining one or more candidate resource configurations of the plurality of candidate resource configurations of the configuration for use by the UE,

[0935] transmitting a reference signal configuration indication to the UE, the reference signal configuration indication indicating the determined one or more candidate resource configurations,

[0936] transmitting the reference signal to the UE, and

[0937] receiving one or more measurement reports from the UE, the measurement reports comprising measurement results for the reference signals measured by the UE based on the indicated one or more candidate resource configurations.

[0938] According to a twenty-first aspect, there is provided an integrated circuit that controls a procedure of a user equipment (UE), the procedure comprising the following steps performed by the UE:

[0939] receiving a reference signal configuration from the base station, the reference signal configuration having a plurality of candidate resource configurations of a reference signal transmittable by the base station to the UE,

[0940] receiving a reference signal configuration indication from the base station, the reference signal configuration indication indicating one or more candidate resource configurations of the configured plurality of candidate resource configurations,

[0941] measuring the reference signal received from the base station based on the indicated candidate resource configuration,

[0942] generating one or more measurement reports, the measurement reports comprising measurement results for the measured reference signals, and

[0943] transmitting the generated measurement reports to the base station.

[0944] According to a twenty-second aspect, there is provided an integrated circuit that controls a procedure of a base station, the procedure comprising the following steps performed by the base station:

[0945] generating a reference signal configuration, the reference signal configuration having a plurality of candidate resource configurations of a reference signal transmittable by the base station to a user equipment (UE),

[0946] transmitting the generated reference signal configuration to the UE,

[0947] determining one or more candidate resource configurations of the configured plurality of candidate resource configurations for use by the UE,

[0948] transmitting a reference signal configuration indication to the UE, the reference signal configuration indication indicating the determined one or more candidate resource configurations,

[0949] transmitting the reference signal to the UE, and

[0950] receiving one or more measurement reports from the UE, the measurement reports comprising measurement results for the reference signals measured by the UE based on the indicated one or more candidate resource configurations.

[0951] Further variations, including hardware and software implementations of the present disclosure

[0952] The present disclosure 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 partly or entirely realized by an LSI such as an integrated circuit, and each process described in each embodiment can be controlled partly 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 so as 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 the manufacture of 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 disclosure 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.

[0953] The present disclosure can be realized by any kind of apparatus, device, or system with a communication function, which is referred to as a communication device.

[0954] The communication device can include a transceiver and processing / control circuitry. The transceiver can include and / or function as a receiver and a transmitter. As the transmitter and the receiver, the transceiver can include an RF (Radio Frequency) module including an amplifier, an RF modulator / demodulator, and the like, and one or more antennas.

[0955] Some non-limiting examples of such a communication device include a telephone (e.g., cellular (cell) phone, smartphone), a tablet, a personal computer (PC) (e.g., laptop, desktop, netbook), a camera (e.g., digital still / video camera), a digital player (digital audio / video player), a wearable device (e.g., wearable camera, smartwatch, tracking device), a game console, a digital book reader, a remote health / telemedicine device, and a vehicle (e.g., automobile, airplane, ship) that provides a communication function, and various combinations thereof.

[0956] The communication device is not limited to be portable or movable, and can also include any kind of apparatus, device, or system that is non-portable or stationary, such as a smart home device (e.g., appliance, lighting, smart meter, control panel), a vending machine, and any other "thing" in a network of "Internet of Things (IoT)".

[0957] The communication can include exchanging data through, for example, a cellular system, a wireless LAN system, a satellite system, etc., and various combinations thereof.

[0958] The communication device can include a device such as a controller or a sensor, which is coupled to a communication device that performs the communication functions described in the present disclosure. For example, the communication device can include a controller or a sensor that generates a control signal or a data signal used by a communication device that performs the communication functions of the communication device.

[0959] The communication device can also include infrastructure such as a base station, an access point, and any other device, apparatus, or system that communicates with or controls devices such as those in the above non-limiting examples.

[0960] (Control signal)

[0961] In the present disclosure, the downlink control signal (information) related to the present disclosure can be a signal (information) transmitted through the PDCCH of the physical layer, or can be a signal (information) transmitted through the MAC control element (CE) or RRC of the higher layer. The downlink control signal can be a pre-defined signal (information).

[0962] The uplink control signal (information) related to the present disclosure can be a signal (information) transmitted through the PUCCH of the physical layer, or can be a signal (information) transmitted through the MAC CE or RRC of the higher layer. In addition, the uplink control signal can be a pre-defined signal (information). The uplink control signal can be replaced with uplink control information (UCI), first-stage sidelink control information (SCI), or second-stage SCI.

[0963] (Base station)

[0964] In the present disclosure, the base station can be, for example, a transmission reception point (TRP), a cluster head, an access point, a remote radio head (RRH), an eNodeB (eNB), a gNodeB (gNB), a base station (BS), a base transceiver station (BTS), a base unit, or a gateway. In addition, in sidelink communication, a terminal can be employed instead of a base station. The base station can be a relay device that relays communication between a higher node and a terminal. The base station can also be a wayside unit.

[0965] (Uplink / downlink / sidelink)

[0966] The present disclosure can be applied to any one of uplink, downlink, and sidelink.

[0967] The present disclosure can be applied to, for example, uplink channels such as a PUSCH, a PUCCH, and a PRACH, downlink channels such as a PDSCH, a PDCCH, and a PBCH, and sidelink channels such as a physical sidelink shared channel (PSSCH), a physical sidelink control channel (PSCCH), and a physical sidelink broadcast channel (PSBCH).

[0968] The PDCCH, the PDSCH, the PUSCH, and the PUCCH are examples of a downlink control channel, a downlink data channel, an uplink data channel, and an uplink control channel, respectively. The PSCCH and the PSSCH are examples of a sidelink control channel and a sidelink data channel, respectively. The PBCH and the PSBCH are examples of a broadcast channel, and the PRACH is an example of a random access channel.

[0969] (Data channel / control channel)

[0970] The present disclosure can be applied to any one of a data channel and a control channel. The channels in the present disclosure can be replaced with a data channel including the PDSCH, the PUSCH, and the PSSCH and / or a control channel including the PDCCH, the PUCCH, the PBCH, the PSCCH, and the PSBCH.

[0971] (Reference signal)

[0972] In the present disclosure, a reference signal is a signal known to both a base station and a mobile station, and each reference signal can be referred to as a reference signal (RS) or sometimes as a pilot signal. The reference signal can be any one of a DMRS, a channel state information reference signal (CSI-RS), a tracking reference signal (TRS), a phase tracking reference signal (PTRS), a cell-specific reference signal (CRS), and a sounding reference signal (SRS).

[0973] (Time interval)

[0974] In the present disclosure, a time resource unit is not limited to one or a combination of a slot and a symbol, and can be a time resource unit such as a frame, a superframe, a subframe, a slot, a slot sub-slot, a mini-slot, or a time resource unit such as a symbol, an orthogonal frequency division multiplexing (OFDM) symbol, a single carrier frequency division multiplexing access (SC-FDMA) symbol, or other time resource units. The number of symbols included in one slot is not limited to any of the numbers of symbols exemplified in the embodiment(s) described above, and can be other numbers of symbols.

[0975] (Frequency band)

[0976] The present disclosure can be applied to any one of a licensed band and an unlicensed band.

[0977] (Communication)

[0978] Any one of communication between terminals (sidelink communication) and vehicle-to-everything (V2X) communication. Channels in this disclosure can be replaced with PSCCH, PSSCH, physical sidelink feedback channel (PSFCH), PSBCH, PDCCH, PUCCH, PDSCH, PUSCH, and PBCH.

[0979] Furthermore, the present disclosure is also applicable to any network in a network other than a terrestrial network or a network using a satellite or a high-altitude pseudo-satellite (HAPS) (NTN: Non-Terrestrial Network). In addition, the present disclosure can be applied to a network having a large cell size, and a terrestrial network having a large delay compared to a symbol length or a slot length, such as an ultra-wideband transmission network.

[0980] (Antenna port)

[0981] An antenna port refers to a logical antenna (antenna group) formed of one or more physical antennas. In other words, the antenna port does not necessarily refer to one physical antenna, and sometimes refers to an array antenna formed of a plurality of antennas, etc. For example, it is not defined how many physical antennas form an antenna port, but the antenna port is defined as a minimum unit that allows a terminal to transmit a reference signal therethrough. The antenna port can also be defined as a minimum unit for multiplication of precoding vector weighting.

[0982] Furthermore, the various embodiments can also be implemented by means of software modules, which are executed by a processor or directly in hardware. A combination of software modules and hardware implementation is also possible. The software modules can be stored in any kind of computer readable storage media, for example RAM, EPROM, EEPROM, flash memory, registers, hard disks, CD-ROM, DVD, etc. It should also be noted that the various features of the different embodiments can be individually or in any combination as subject of another embodiment.

[0983] Those skilled in the art will understand that many changes and / or modifications can be made to the present disclosure as shown in the specific embodiments. Therefore, the present embodiments are considered in all aspects to be illustrative and not restrictive.

Claims

1. A user equipment (UE), comprising: A receiver receives a reference signal configuration from a base station, the reference signal configuration having multiple candidate resource configurations for a reference signal transmitted by the base station to the UE. The receiver receives a reference signal configuration indication from the base station, the reference signal configuration indication indicating one or more candidate resource configurations among the plurality of candidate resource configurations. A processor that measures the reference signal received from the base station based on an indicated candidate resource configuration.

2. The user equipment according to claim 1, wherein, The processor generates one or more measurement reports, which include measurement results for the measured reference signal, and The UE's transmitter sends the generated measurement report to the base station.

3. The user equipment according to claim 1 or 2, wherein, By defining candidate transmission characteristics for the reference signals with different values, at least two of the plurality of candidate resource configurations are different from each other, wherein the different candidate transmission characteristics are one or more of the following: • Different antenna port modes for the reference signal • Different transmission powers for the reference signal, and • Used for different transmit powers of the downlink data channel for measuring the reference signal. Optionally, the plurality of candidate resource configurations further define: • Radio resource elements used to carry the reference signal in the frequency and time domains.

4. The user equipment according to claim 3, wherein, The antenna port mode used for the reference signal is defined by the candidate resource configuration based on one or more of the following: • Code Division Multiplexing (CDM) Group Index • Antenna port index, and • A combination of CDM group index and antenna port index, and Optionally, the transmit power of the downlink data channel is defined based on a power offset relative to the reference signal. Optionally, the transmission power for the reference signal is defined based on the power offset of the synchronization signal block transmitted from the base station.

5. The user equipment according to any one of claims 1 to 4, wherein, At least one of the plurality of candidate resource configurations is defined such that at least one transmission characteristic defined by the at least one candidate resource configuration is different from the transmission characteristic actually used by the base station. Optionally, the different transmission characteristic refers to one or more of the following: • Different antenna port patterns, such as a subset of all antenna ports actually used by the base station to transmit the reference signal, and • Different transmission powers, for example, lower or higher than the transmission power actually used by the base station to transmit the reference signal. • Different transmission power, for example, lower or higher than the transmission power that the base station actually uses to transmit the downlink data channel.

6. The user equipment according to any one of claims 1 to 5, wherein, The reference signal configuration configures one or more radio resources for the reference signal, wherein at least one radio resource is defined with two or more different candidate transmission characteristics for the reference signal. Optionally, the reference signal is configured to configure one or more radio resource sets, wherein each radio resource set indicates one or more radio resources for the reference signal.

7. The UE according to any one of claims 1 to 6, wherein, The reference signal configuration indication indicates the one or more candidate resource configurations based on one or more of the following: • Group ID, wherein each of the plurality of candidate resource configurations is associated with one of the plurality of group IDs. • A bitmap, wherein each bit of the bitmap is associated with one or more candidate resource configurations among the plurality of candidate resource configurations, and a value of the bit of the bitmap indicates that the measurement of the reference signal should be based on the associated one or more candidate resource configurations, and • Codewords, wherein each codeword is associated with one or more candidate resource configurations among the plurality of candidate resource configurations. Optionally, the reference signal configuration indication is received by the UE as a Radio Resource Control (RRC) message, a Medium Access Control (MAC) control element, or a Downlink Control Information (DCI) message. Optionally, the reference signal configuration is received by the UE as a Radio Resource Control (RRC) message. Optionally, the generation and transmission of measurement reports are performed periodically, semi-permanently, or non-periodically by the UE.

8. The UE according to any one of claims 1 to 7, wherein, The receiver receives a report configuration from the base station, the report configuration including multiple sub-configurations, each of the multiple sub-configurations configuring one or more of the following: A collection of measurement report quantities, such as one or more of the following: channel quality parameters, channel quality indicators, precoding matrix indicators, reference signal indicators, layer indicators, and rank indicators. An uplink channel transmission configuration, which configures one or more of the time and frequency of radio resources for the uplink channel, and is capable of transmitting measurement results for a corresponding sub-configuration. The receiver receives a report indicating one or more of the sub-configurations. The processor generates a measurement report based on one or more indicated sub-configurations.

9. The UE according to claim 8, wherein, The sub-configuration also includes the reference signal configuration that defines the reference signal. Optionally, the sub-configuration further includes the reference signal configuration regarding one or more candidate resource configurations with different transmission characteristics that can be transmitted by the base station to the UE.

10. The UE according to claim 8 or 9, wherein, An uplink channel transmission configuration is configured as follows: • According to each sub-configuration, or • At least two sub-configurations share this feature, or • All sub-configurations are shared. Optionally, where, A set of measurement report quantities is configured as follows: • According to each sub-configuration, or • For at least two sub-configurations, or • For all sub-configurations, Optionally, one of the reference signals is configured as follows: • According to each sub-configuration, or • For at least two sub-configurations, or • Applicable to all sub-configurations.

11. The UE according to any one of claims 8 to 10, wherein, The report indicates the one or more sub-configurations based on one or more of the following: • Group ID, wherein each of the plurality of sub-configurations is associated with one of the plurality of group IDs. • A bitmap, wherein each bit of the bitmap is associated with one or more of the sub-configurations, and a value of one bit of the bitmap indicates that the generation and transmission of a measurement report should be based on the associated sub-configuration, and • Codewords, wherein each codeword is associated with a combination of two or more sub-configurations from the plurality of sub-configurations. Optionally, the report indication indicates either the first N sub-configurations or the last N sub-configurations among all the plurality of sub-configurations. Optionally, the report indication is received by the UE as a Radio Resource Control (RRC) message, a Media Access Control (MAC) control element, or a Downlink Control Information (DCI) message. Optionally, the report configuration is received by the UE as a Radio Resource Control (RRC) message, and Optionally, the generation and transmission of measurement reports are performed by the UE periodically, semi-permanently, or non-periodically.

12. The UE according to any one of claims 1 to 11, in, The processor determines the priority of the measurement results to be sent to the base station, wherein the priority of the measurement results depends on a priority determination rule based on one or more of the following: • Measurements determined based on a report configuration with multiple sub-configurations have a higher or lower priority than measurements determined based on a report configuration without multiple sub-configurations. • The number of sub-configurations in the report configuration, optionally, wherein the more sub-configurations in the report configuration, the higher or lower the priority of the measurement results determined based on the report configuration, and • The lower the index associated with a sub-configuration of the report configuration, the higher or lower the priority of the measurement results determined based on that sub-configuration.

13. The UE according to claim 12, wherein, The priority determination rule used to determine the priority of the measurement results is also based on one or more of the following: The higher the rank indicated by the rank indicator of the measurement result, the higher or lower the priority of the measurement result. The higher the channel quality indicated by the channel quality indicator of the measurement result, the higher or lower the priority of the measurement result. Optionally, the priority determination rule for determining the priority of the measurement results is further based on one or more of the following: The lower the index associated with the report configuration, the higher or lower the priority of the measurement result determined based on the report configuration.

14. The UE according to claim 12 or 13, wherein, The processor takes into account the priority of the measurement results for one or more of the following processes: The generation of a bit sequence carrying uplink control information of the measurement results, optionally, involves taking into account the priority of the measurement results when determining the order of the bits generated by the bit sequence generation. The discarding of measurement results may optionally involve discarding the measurement results in an increasing order of priority.

15. The UE according to any one of claims 1 to 14, wherein, Multiple measurement results will be sent to the base station, wherein at least one of the measurement results is determined based on a report configuration with multiple sub-configurations or a candidate resource configuration based on one of multiple candidate resource configurations of the reference signal. The processor determines whether to send one or more of the plurality of measurement results based on a discarding rule, wherein the discarding rule is based on one or more of the following: Discard measurements with low priority. Measurements with rank indicators that indicate rank is above or below the rank threshold are not discarded. Measurements with channel quality indicators that suggest channel quality is above or below a channel quality threshold are not discarded. Measurement results are selected for transmission in descending priority order until the capacity limit of the uplink channel resources used to carry the measurement results is reached. Unselected measurement results are then discarded. Optionally, the capacity limit is determined by the UE based on the amount of available resources in the uplink channel or based on an indication received by the base station via one or more of the following: Radio Resource Control (RRC) messages, Medium Access Control (MAC) control elements, or Downlink Control Information (DCI) messages. Measurement results are selected for transmission in descending priority order until the processing limit for the UE to process the measurement results is reached, wherein the remaining unselected measurement results are discarded. Optionally, the processing limit is determined by the UE based on an indication received from the base station via one or more of the following: Radio Resource Control (RRC) messages, Medium Access Control (MAC) control elements, or Downlink Control Information (DCI) messages. Of the multiple measurement results, N measurement results are selected, optionally, the measurement results generated based on the first N sub-configurations or the last N sub-configurations are discarded; optionally, the first N measurement results with the highest or lowest rank indicator are discarded; optionally, the first N measurement results with the highest or lowest channel quality indicator are discarded; optionally, the UE determines the number N from the Medium Access Control (MAC) control element or the Downlink Control Information (DCI) message.

16. The UE according to claim 15, wherein, The discard rule applies in one or more of the following situations: In the event that not all of the aforementioned measurement results can be sent... In the case of conflicting measurements in the time domain When the total capacity used to transmit the plurality of measurement results is greater than the upper limit of the capacity of the uplink channel resources used to carry the measurement results, and When the total processing for sending the plurality of measurement results exceeds the processing limit for the UE to process the measurement results.

17. The UE according to claim 15 or 16, wherein, The measurement results were sent in two parts. Wherein, when the processor applies the discard rule, the discard rule is applied by the processor to: Both the first and second parts of the measurement results, or The first part of the measurement result, not the second part, or The second part of the measurement result, not the first part, and Optionally, the first part has a fixed bit size, includes some measurement results, and also identifies the number of bits in the second part.

18. The UE according to any one of claims 15 to 17, wherein, The processor generates a UE capability indication, which indicates one or more of the following: • Maximum number of report configurations • The maximum number of report configurations with multiple sub-configurations. • The maximum number of sub-configurations within the report configuration, and • Maximum total number of sub-configurations across all reporting configurations Optionally, the processor determines one or more of the maximum number of sub-configurations and the maximum total number of sub-configurations based on a scaling factor, wherein the scaling factor is a value between 0 and 1 multiplied for each sub-configuration.

19. A base station, comprising: A processor that generates a reference signal configuration having multiple candidate resource configurations for a reference signal transmitted by the base station to the user equipment (UE). A transmitter that sends the reference signal configuration to the UE. The processor determines one or more candidate resource configurations from the plurality of candidate resource configurations for use by the UE. The transmitter sends a reference signal configuration indication to the UE, the reference signal configuration indication indicating one or more determined candidate resource configurations, and The transmitter sends the reference signal to the UE.

20. The base station according to claim 19, further comprising: A receiver receives one or more measurement reports from the UE, the measurement reports including measurement results of the reference signal measured by the UE based on one or more indicated candidate resource configurations.

21. A method comprising the following steps performed by a user equipment (UE): The reference signal configuration is received from the base station, the reference signal configuration having multiple candidate resource configurations for reference signals transmitted by the base station to the UE. A reference signal configuration indication is received from the base station, the reference signal configuration indication indicating one or more candidate resource configurations among the plurality of candidate resource configurations, and The reference signal received from the base station is measured based on the indicated candidate resource configuration.

22. The method of claim 21, further comprising the step performed by the UE: Generate one or more measurement reports, which include measurement results for the measured reference signal, and The generated measurement report is sent to the base station.

23. A method comprising the following steps performed by a base station: A reference signal configuration is generated, the reference signal configuration having multiple candidate resource configurations for reference signals transmitted by the base station to the user equipment (UE). Send the reference signal configuration to the UE. One or more candidate resource configurations from the plurality of candidate resource configurations are determined for use by the UE. A reference signal configuration indication is sent to the UE, the reference signal configuration indication indicating one or more determined candidate resource configurations, and The reference signal is sent to the UE.

24. The method of claim 23, further comprising the steps performed by the base station: The UE receives one or more measurement reports, the one or more measurement reports including measurement results of the reference signal measured by the UE based on one or more indicated candidate resource configurations.

25. An integrated circuit that controls a user equipment (UE) process, the process comprising the following steps performed by the UE: The reference signal configuration is received from the base station, the reference signal configuration having multiple candidate resource configurations for reference signals transmitted by the base station to the UE. A reference signal configuration indication is received from the base station, the reference signal configuration indication indicating one or more candidate resource configurations among the plurality of candidate resource configurations. The reference signal received from the base station is measured based on the indicated candidate resource configuration.

26. The integrated circuit of claim 25, wherein the process includes the following steps performed by the UE: Generate one or more measurement reports, which include measurement results for the measured reference signal, and The generated measurement report is sent to the base station.

27. An integrated circuit that controls a base station process, the process comprising the following steps performed by the base station: A reference signal configuration is generated, the reference signal configuration having multiple candidate resource configurations for reference signals transmitted by the base station to the user equipment (UE). Send the reference signal configuration to the UE. One or more candidate resource configurations from the plurality of candidate resource configurations are determined for use by the UE. A reference signal configuration indication is sent to the UE, the reference signal configuration indication indicating one or more determined candidate resource configurations, and The reference signal is sent to the UE.

28. The integrated circuit according to claim 27, wherein, The process includes the following steps performed by the base station: The UE receives one or more measurement reports, the one or more measurement reports including measurement results of the reference signal measured by the UE based on one or more indicated candidate resource configurations.

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