Base station, communication method, communication device, and integrated circuit

Abstract

The base station includes: control circuitry that decides a configuration method of a downlink control channel signal for at least one of a first period before a carrier sensing-based occasion and a second period after the carrier sensing-based occasion, based on information related to at least one of a number of blind decodes for the downlink control channel signal and a number of resources for channel estimation; and transmission circuitry that transmits the downlink control channel signal based on the decided configuration method.

Description

Technical Field

[0001] This invention relates to a base station, a terminal, a transmitting method, and a receiving method. Background Technology

[0002] The 3rd Generation Partnership Project (3GPP) has completed the planning and formulation of Release 15NR (New Radio access technology) specifications for the implementation of fifth-generation mobile communication systems (5G). In NR, the basic requirements of enhanced mobile broadband (eMBB), namely high speed and high capacity, are combined to support the functionality of ultra-reliable and low-latency communication (URLLC) (see, for example, Non-Patent Literature 1-Non-Patent Literature 4).

[0003] Existing technical documents

[0004] Non-patent literature

[0005] Non-patent document 1: 3GPP TS 38.211 V15.7.0, "NR; Physical channels and modulation (Release 15)," September 2019

[0006] Non-patent document 2: 3GPP TS 38.212 V15.7.0, "NR; Multiplexing and channel coding (Release 15)," September 2019

[0007] Non-patent literature 3: 3GPP TS 38.213 V15.7.0, "NR; Physical layer procedure for control (Release 15)," September 2019

[0008] Non-patent literature 4: 3GPP TS 38.214 V15.7.0, "NR; Physical layer procedures for data (Release 15)," September 2019 Summary of the Invention

[0009] However, the methods for transmitting downlink signals in unlicensed frequency bands have not been fully studied.

[0010] Non-limiting embodiments of the present invention help to provide base stations, terminals, transmission methods, and reception methods that can improve the transmission efficiency of downlink signals in unlicensed frequency bands.

[0011] A terminal according to one embodiment of the present invention includes: a control circuit that determines a configuration method for the downlink control channel signal during at least one of a first period before a carrier-based sensing opportunity and a second period after the carrier-based sensing opportunity, based on information relating to at least one of the number of blind decodings of the downlink control channel signal and the number of resources estimated for the channel; and a transmission circuit that transmits the downlink control channel signal based on the determined configuration method.

[0012] It should be noted that these general or specific methods can be implemented by systems, devices, methods, integrated circuits, computer programs or recording media, or by any combination of systems, devices, methods, integrated circuits, computer programs and recording media.

[0013] According to one embodiment of the present invention, the transmission efficiency of downlink signals in unlicensed frequency bands can be improved.

[0014] Further advantages and effects of one embodiment of the present invention will be illustrated by the description and drawings. These advantages and / or effects are provided by the various embodiments and the features described in the description and drawings, but not necessarily all of them need to be provided in order to obtain one or more of the same features. Attached Figure Description

[0015] Figure 1 This is a diagram illustrating the exemplary architecture of a 3GPP NR system.

[0016] Figure 2 This is a schematic diagram illustrating the functional separation between NG-RAN (Next Generation-Radio Access Network) and 5GC (5th Generation Core).

[0017] Figure 3 This is a sequence diagram of the setting / resetting process for an RRC (Radio Resource Control) connection.

[0018] Figure 4This is a schematic diagram illustrating the application scenarios of enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), and ultra-reliable and low-latency communications (URLLC).

[0019] Figure 5 This is a block diagram representing an exemplary 5G system architecture for non-roaming scenarios.

[0020] Figure 6 This is a diagram illustrating an example of the maximum number of blind detections (BD) and the maximum number of control channel elements (CCE).

[0021] Figure 7 This is a diagram illustrating an example of a phase in downlink (DL) burst detection.

[0022] Figure 8 This is a diagram illustrating an example of the configuration of CORESET (Control Resource Set) and synchronization signal (SS) in multiple subbands.

[0023] Figure 9 This is a diagram illustrating a setting example for a PDCCH (Physical Downlink Control Channel) monitoring occasion.

[0024] Figure 10 It is a block diagram representing a part of the structure of a base station.

[0025] Figure 11 It is a block diagram representing a part of the structure of the terminal.

[0026] Figure 12 It is a block diagram representing the structure of a base station.

[0027] Figure 13 It is a block diagram representing the structure of the terminal.

[0028] Figure 14 This is a sequence diagram representing the actions of a base station and a terminal.

[0029] Figure 15This is a diagram illustrating an example of setting up a PDCCH monitoring opportunity in the decision method 1 of Implementation Method 1.

[0030] Figure 16 This is a diagram illustrating a variation of the decision method 1 of Implementation 1, specifically a PDCCH monitoring opportunity setting example.

[0031] Figure 17 This is a diagram illustrating an example of setting the PDCCH monitoring opportunity in the decision method 2 of Implementation Method 1.

[0032] Figure 18 This is a diagram illustrating an example of setting up a PDCCH monitoring opportunity in Implementation Method 2.

[0033] Figure 19 This is a diagram illustrating an example of setting up a PDCCH monitoring opportunity in Implementation Method 3. Detailed Implementation

[0034] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0035] <5G NR System Architecture and Protocol Stack>

[0036] To realize the next version of fifth-generation mobile phone technology (also known simply as "5G"), which includes the development of a new radio access technology (NR) operating in the frequency range up to 100 GHz, 3GPP is continuing its work. The first version of the 5G standard was completed at the end of 2017, thus enabling the transition to the trial production of terminals (e.g., smartphones) according to the 5G NR standard and commercial deployment.

[0037] For example, the overall system architecture envisions a gNB-RAN (Next Generation Radio Access Network). The gNB provides the UE (User Equipment) side termination for the NG radio access protocols (SDAP (Service Data Adaptation Protocol) / PDCP (Packet Data Convergence Protocol) / RLC (Radio Link Control) / MAC (Medium Access Control) / PHY (Physical Layer)) and control plane (RRC). gNBs are interconnected via the Xn interface. Additionally, gNBs are connected to the NGC (Next Generation Core) via the Next Generation (NG) interface, and more specifically, to the AMF (Access and Mobility Management Function) (e.g., a specific core entity implementing the AMF) via the NG-C interface, and to the UPF (User Plane Function) (e.g., a specific core entity implementing the UPF) via the NG-U interface. Figure 1 This refers to the NG-RAN architecture (e.g., refer to 3GPP TS 38.300v15.6.0, section 4).

[0038] The user plane protocol stack for NR (e.g., see 3GPP TS 38.300, section 4.4.1) comprises the PDCP (Packet Data Convergence Protocol, see TS 38.300, section 6.4) sublayer, RLC (Radio Link Control, see TS 38.300, section 6.3) sublayer, and MAC (Media Access Control, see TS 38.300, section 6.2) sublayer, which terminates on the network side in the gNB. Additionally, a new Access Stratum (AS) sublayer (SDAP: Service Data Adaptation Protocol) has been incorporated into PDCP (e.g., see 3GPP TS 38.300, section 6.5). Furthermore, a control plane protocol stack is defined for NR (e.g., see TS 38.300, section 4.4.2). A summary of Layer 2 functionality is described in Section 6 of TS 38.300. The functions of the PDCP sublayer, RLC sublayer, and MAC sublayer are listed in Sections 6.4, 6.3, and 6.2 of TS 38.300, respectively. The functions of the RRC layer are listed in Section 7 of TS 38.300.

[0039] For example, the media access control layer handles the multiplexing of logical channels, scheduling of processing involving various parameter sets, and various functions associated with scheduling.

[0040] For example, the Physical Layer (PHY) is responsible for encoding, PHY HARQ (Physical Layer Hybrid Automatic Repeat Request) processing, modulation, multi-antenna processing, and mapping signals to appropriate physical time-frequency resources. Additionally, the Physical Layer handles the mapping of physical channels to transport 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 to transmit a specific transport channel; each transport channel is mapped to a corresponding physical channel. For example, in physical channels, uplink physical channels include PRACH (Physical Random Access Channel), PUSCH (Physical Uplink Shared Channel), and PUCCH (Physical Uplink Control Channel), while downlink physical channels include PDSCH (Physical Downlink Shared Channel), PDCCH (Physical Downlink Control Channel), and PBCH (Physical Broadcast Channel).

[0041] In NR use cases / extended scenarios, enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine-type communications (mMTC) can be included, each with multiple requirements in terms of data rate, latency, and coverage. For example, eMBB is expected to support peak data rates approximately three times that of IMT-Advanced (20Gbps in downlink and 10Gbps in uplink) and effective (user-experienced) data rates. On the other hand, in the case of URLLC, ultra-low latency (0.5ms in both UL and DL for the user plane) and high reliability (within 1ms, 1-10) are expected. -5 This introduces more stringent requirements. Finally, in mMTC, a high connection density is preferably required (1,000,000 devices / km in urban environments). 2 ), wide coverage in harsh environments and extremely long battery life (15 years) for inexpensive devices.

[0042] Therefore, a set of OFDM (Orthogonal Frequency Division Multiplexing) parameters suitable for one use case (e.g., subcarrier spacing (SCS), OFDM symbol length, cyclic prefix (CP) length, number of symbols per scheduling interval) may be ineffective for other use cases. For example, in low-latency services, it is preferable to require a shorter symbol length (and therefore a larger subcarrier spacing) and / or fewer symbols per scheduling interval (also known as "TTI"). Moreover, in extended scenarios with large channel delay spread, it is preferable to require a longer CP length than in scenarios with shorter delay spread. The subcarrier spacing can also be optimized depending on the situation to maintain the same CP overhead. NR supports more than one subcarrier spacing value. Correspondingly, subcarrier spacings of 15kHz, 30kHz, 60kHz, etc., are currently considered. Symbol length T u The subcarrier spacing Δf is calculated according to the formula Δf=1 / T uAnd directly related. Similar to the LTE (Long Term Evolution) system, the term "resource element" can be used to represent the smallest unit of resources consisting of a subcarrier of the length of one OFDM / SC-FDMA (Single-Carrier Frequency Division Multiple Access) symbol.

[0043] In the new 5G-NR wireless system, resource grids for subcarriers and OFDM symbols are defined in both the uplink and downlink for each parameter set and each carrier. Each element of the resource grid is called a "resource element," which is determined based on the frequency index in the frequency domain and the symbol position in the time domain (refer to 3GPP TS 38.211 v15.6.0).

[0044] <Functional Separation between NG-RAN and 5GC in 5G NR>

[0045] Figure 2 This indicates the functional separation between NG-RAN and 5GC. The logical node of NG-RAN is either gNB or ng-eNB. 5GC has logical nodes AMF, UPF, and SMF (Session Management Function).

[0046] For example, gNB and ng-eNB host the following main functions:

[0047] - Functions such as Radio Bearer Control, Radio Admission Control, Connection Mobility Control, and Radio Resource Management (RRM) that dynamically allocates (schedules) resources to the UE in both the uplink and downlink links;

[0048] - Data IP (Internet Protocol) header compression, encryption, and integrity protection;

[0049] - Selection of AMF when attaching a UE in situations where the route to the AMF cannot be determined based on the information provided by the UE;

[0050] - Routing to user plane data towards UPF;

[0051] - Routing of control plane information toward AMF;

[0052] - Setting and canceling connections;

[0053] - Scheduling and sending paging messages;

[0054] - The scheduling and transmission of system broadcast information (originating from AMF or Operation, Admission, and Maintenance functions (OAM));

[0055] - Setting up measurements and measurement reports for mobility and scheduling;

[0056] - Packet markings for transmission class in the uplink;

[0057] -Session management;

[0058] -Support for network slicing;

[0059] - QoS (Quality of Service) flow management and mapping to data radio bearers;

[0060] Support for UEs in RRC_INACTIVE (RRC inactive) state;

[0061] - NAS (Non-Access Stratum) message distribution function;

[0062] - Sharing of wireless access networks;

[0063] - Dual connectivity;

[0064] - Close collaboration between NR and E-UTRA (Evolved Universal Terrestrial Radio Access).

[0065] The Access and Mobility Management Function (AMF) administers the following main functions:

[0066] - Function to terminate Non-Access Stratum (NAS) signaling;

[0067] -Security of NAS signaling;

[0068] - Security controls at the access layer (AS);

[0069] - Core Network (CN) inter-node signaling for mobility between 3GPP access networks;

[0070] - The possibility of a UE reaching idle mode (including control and execution of paging retransmission);

[0071] - Management of the registered area;

[0072] - Support for intra-system mobility and inter-system mobility;

[0073] -Access authentication;

[0074] - Access licenses that include roaming permission checks;

[0075] - Mobility management controls (subscription and policies);

[0076] -Support for network slicing;

[0077] - Selection of Session Management Function (SMF).

[0078] In addition, the User Face Function (UPF) hosts the following main functions:

[0079] - Anchor points for intra-RAT (Radio Access Technology) mobility / inter-RAT (where applicable) mobility;

[0080] - External PDU (Protocol Data Unit) session points used for interconnection with data networks;

[0081] - Packet routing and forwarding;

[0082] - Enforcement of policy rules in group checks and user-facing aspects;

[0083] - Reports on business usage;

[0084] - Uplink classifier used to support routing of service flows toward the data network;

[0085] - Branching points used to support multi-homed PDU sessions;

[0086] - For user plane QoS processing (e.g., packet filtering, gating, UL / DL rate enforcement);

[0087] - Uplink service verification (SDF (Service Data Flow) mapping to QoS flow);

[0088] - Downlink packet buffering and downlink data notification triggering functions.

[0089] Finally, the Session Management Function (SMF) administers the following main functions:

[0090] -Session management;

[0091] - The allocation and management of UE IP addresses;

[0092] -Selection and control of UPF;

[0093] - A function for setting traffic steering in the User Plane Function (UPF) to direct traffic to the appropriate destination;

[0094] - Enforcing policies and QoS in the control section;

[0095] - Notification of downlink data.

[0096] <The process of setting up and resetting RRC connection>

[0097] Figure 3 This refers to several interactions between the UE, gNB, and AMF (5GC entity) when the UE in the NAS part transitions from RRC_IDLE (RRC idle) to RRC_CONNECTED (RRC connected) (refer to TS 38.300v15.6.0).

[0098] RRC is a higher-level signaling (protocol) used for UE and gNB configuration. Through this transition, the AMF prepares UE context data (which includes, for example, PDU session context, security keys, UE radio capabilities, and UE security capabilities) and sends it to the gNB along with an initial context setting request. Next, the gNB and UE activate AS security together. The gNB sends a SecurityModeCommand message to the UE, and the UE responds with a SecurityModeComplete message, thereby activating AS security. Then, the gNB sends an RRCReconfiguration message to the UE, and receives an RRCReconfigurationComplete message from the UE for this message, thus performing the reconfiguration of Signaling RadioBearer 2 (SRB2) and Data Radio Bearer (DRB). For signaling-only connections, since SRB2 and DRB are not configured, the steps related to RRC reconfiguration can be omitted. Finally, the gNB notifies the AMF that the configuration process is complete using the Initial Context Setup Reply.

[0099] Therefore, this invention provides a fifth-generation core network (5GC) entity (e.g., AMF, SMF, etc.) comprising: a control circuit that, upon operation, establishes a Next Generation (NG) connection with a gNodeB; and a transmission unit that, upon operation, transmits an initial context setting message to the gNodeB via the NG connection to set the signaling radio bearer between the gNodeB and the User Equipment (UE). Specifically, the gNodeB transmits Radio Resource Control (RRC) signaling containing an Information Element (IE) to the UE via the signaling radio bearer. The UE then performs uplink transmission or downlink reception based on the resource allocation settings.

[0100] <Application Scenarios of IMT after 2020>

[0101] Figure 4This section outlines several use cases for 5G NR. Within the 3rd Generation Partnership Project New Radio (3GPP NR), three use cases supporting a wide variety of services and applications, conceived through IMT-2020, have been studied. Planning for the first phase of specifications for enhanced mobile broadband (eMBB) has been completed. Current and future work, in addition to gradually expanding eMBB support, includes standardization for ultra-reliable and low-latency communications (URLLC) and massive machine-type communications (mMTC). Figure 4 Several examples illustrating conceptual application scenarios for IMT after 2020 (e.g., referring to ITU-R M.2083). Figure 2 ).

[0102] URLLC use cases have strict requirements related to performance aspects such as throughput, latency, and availability. URLLC is conceived as a key technology for enabling wireless control of future industrial production or manufacturing processes, remote medical surgery, automation of power transmission and distribution in smart grids, and traffic safety applications. Ultra-high reliability of URLLC is supported by defining technologies that meet the requirements set by TR38.913. In NR URLLC version 15, a crucial requirement is a target user plane latency of 0.5ms in the UL (uplink) and 0.5ms in the DL (downlink). For a single packet transmission, the overall requirement for URLLC is a block error rate (BLER) of 1E-5 for a 32-byte packet size with a user plane latency of 1ms.

[0103] Considering the physical layer, numerous methods are available to improve reliability. Current possibilities for reliability enhancement include defining alternative CQI (Channel Quality Indicator) tables for URLLC, a more compact DCI (Downlink Control Information) format, and PDCCH iteration. However, as NR (a crucial prerequisite for NR URLLC) becomes more stable and is further developed, this scope can be expanded to achieve ultra-high reliability. Specific use cases for NR URLLC in version 15 include augmented reality / virtual reality (AR / VR), e-health, e-safety, and other critical applications.

[0104] Furthermore, technical enhancements targeting NR URLLC aim to improve latency and reliability. Latency enhancements include configurable parameter sets, non-slot-based scheduling utilizing flexible mapping, unlicensed (already licensed) uplinks, slot-level repetition in the data channel, and pre-emption in the downlink. Pre-emption refers to stopping transmissions with allocated resources and using those resources for later-requested transmissions that require lower latency / higher priority. Therefore, a permitted transmission is replaced by a subsequent transmission. Pre-emption can be applied regardless of the specific service type. For example, a transmission in service type A (URLLC) can be replaced by a transmission in service type B (eMBB, etc.). Reliability enhancements include a dedicated CQI / MCS (Modulation and Coding Scheme) table for a target BLER of 1E-5.

[0105] The use cases for mMTC (massive machine-type communications) are characterized by a large number of connected devices that transmit relatively small amounts of data that are not easily affected by latency. These devices require low cost and very long battery life. From NR's perspective, utilizing very narrow bandwidth is a solution to save UE power and extend its battery life.

[0106] As mentioned above, the potential for improved reliability in NR is further expanded. It is one of the essential conditions for all situations; for example, high or ultra-high reliability is a crucial requirement related to URLLC and mMTC. From both wireless and network perspectives, reliability can be improved through several mechanisms. Generally, there are two to three important areas that could potentially contribute to improved reliability. These areas include compact control channel information, data / control channel iteration, and diversity related to the frequency, time, and / or spatial domains. These areas can be used universally to improve reliability, independent of specific communication scenarios.

[0107] Regarding NR URLLC, further use cases with more stringent requirements are envisioned, such as factory automation, transportation, and power transmission. Strict requirements refer to high reliability (achieving 10...). -6 High reliability, high availability, packet size up to 256 bytes, and time synchronization up to several microseconds (μs) (capable of setting the value to 1 μs or several microseconds depending on the use case, frequency range, and short latency of about 0.5ms to 1ms (e.g., 0.5ms latency in the target user plane)).

[0108] Furthermore, from a physical layer perspective, there are several technical enhancements to NR URLLC. These enhancements include strengthening the PDCCH (Physical Downlink Control Channel) associated with compact DCI, PDCCH repetition, and increased PDCCH monitoring. Additionally, enhancements to UCI (Uplink Control Information) are related to enhanced HARQ (Hybrid Automatic Repeat Request) and CSI feedback. Furthermore, there may be enhancements to PUSCH and retransmission / repetition related to micro-slot-level frequency hopping. The term "micro-slot" refers to a transmission time interval (TTI) containing fewer symbols than a time slot (a time slot has 14 symbols).

[0109] <QoS Control>

[0110] 5G's QoS (Quality of Service) model is based on QoS flows, supporting both QoS flows that require guaranteed bit rate (GBR) and QoS flows that do not require guaranteed bit rate (non-GBR QoS flows). Therefore, at the NAS level, QoS flows represent the finest granular QoS classification within a PDU session. QoS flows are determined within a PDU session based on the QoS Flow ID (QFI) transmitted via the encapsulation header through the NG-U interface.

[0111] For each UE, 5GC establishes one or more PDU sessions. For each UE, in conjunction with the PDU session, NG-RAN, for example, refers to the previous text. Figure 3 As explained, at least one Data Radio Bearer (DRB) is established. Additionally, DRBs can be subsequently configured in QoS flows added to this PDU session (when to configure this depends on the NG-RAN). The NG-RAN maps packets belonging to various PDU sessions to various DRBs. NAS-level packet filters in the UE and 5GC are used to 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.

[0112] Figure 5 This refers to the non-roaming reference architecture of 5G NR (refer to TS 23.501v16.1.0, section 4.23). Application Function (AF) (e.g., hosting...) Figure 4 The external application server (exemplified in the 5G service example) interacts with the 3GPP core network to provide services. For example, it may access a Network Exposure Function (NEF) to support applications that impact service routing, or it may interact with a policy framework (see Policy Control Function (PCF)) for policy control (e.g., QoS control). Based on operator deployment, operators deem trusted application functions capable of directly interacting with associated network functions. Application functions not permitted by the operator to directly access network functions interact with associated network functions via the NEF, using an open framework accessible to the outside world.

[0113] Figure 5It also indicates further functional units of the 5G architecture, namely, the Network Slice Selection Function (NSSF), the Network Repository Function (NRF), 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: Data Network, such as services provided by operators, internet access, or services provided by third parties). All or part of the core network's functions and application services can also be deployed and operate in a cloud computing environment.

[0114] Therefore, the present invention provides an application server (e.g., an AF in a 5G architecture) comprising: a transmitting unit that, in order to establish a PDU session containing a radio bearer between a g node B and a UE corresponding to QoS requirements, sends at least one of the following functions (e.g., NEF, AMF, SMF, PCF, UPF, etc.) to the 5GC during operation: a request containing QoS requirements for at least one of URLLC service, eMMB service, and mMTC service; and a control circuit that, during operation, performs services using the established PDU session.

[0115] In version 15NR, for a terminal (or, also referred to as a "User Equipment (UE)"), the following definitions are made: the number of downlink control channels (e.g., PDCCH: Physical Downlink Control Channel) that can be blindly decoded (or, also referred to as "monitoring") in one slot, and the number of control channel elements (CCEs) that can be used for channel estimation in the PDCCH. Furthermore, the number of PDCCHs that can be blindly decoded in one slot is also referred to, for example, as the "maximum number of blind decodes" or "maximum number of BDs". Additionally, the number of CCEs that can be used for channel estimation in the PDCCH is also referred to as the "maximum number of CCEs". The base station (e.g., also referred to as a "gNB") transmits PDCCHs based, for example, the number of BDs or CCEs allocated to each terminal.

[0116] Furthermore, version 16NR investigated NR-Unlicensed (NR-U) communication using NR-based radio access methods in unlicensed frequency bands (or, also known as "unlicensed bands"). In unlicensed bands, devices perform carrier listening (e.g., "Listen Before Talk (LBT")) to confirm whether other systems or terminals are using the radio channel before transmitting. In NR-U, the decision to transmit is based, for example, on the results of LBT. Therefore, the process of detecting the start of transmission of a series of downlink data (e.g., downlink bursts) in the terminal was investigated. For example, version 16NR investigated the detection of DL bursts based on PDCCH.

[0117] [Maximum BD count and maximum CCE count]

[0118] For example, it can be like Figure 6 The maximum number of BDs and the maximum number of CCEs are defined as follows (for example, see Non-Patent Literature 3). Figure 6 The maximum number of BDs and the maximum number of CCEs shown are, for example, values ​​for each terminal and each time slot.

[0119] In version 15NR, for example, it is possible to set the terminal to exceed [a certain limit]. Figure 6 The maximum number of BDs or the maximum number of CCEs (in other words, the upper limit) are shown as PDCCH candidates. In this case, a "dropping rule" (in other words, a rule for not assigning PDCCH candidates and PDCCH monitoring opportunities) is defined to set the actual PDCCH candidates as... Figure 6 The method shown is below the maximum number of BDs or the maximum number of CCEs.

[0120] In addition, "PDCCH candidate" refers to a candidate for receiving PDCCH by the terminal. For example, PDCCH monitoring opportunity (or PDCCH reception opportunity) refers to the frequency and time resources of the PDCCH candidate.

[0121] The following provisions can be applied, for example, in the discard rules.

[0122] - Do not discard PDCCH candidates and PDCCH monitoring opportunities in the common search space (CSS).

[0123] - In the UE-specific search space (USS), if the number of PDCCH candidates exceeds the maximum number of BDs or the minimum number of CCEs, the search space is discarded (in other words, no resources are allocated) in descending order of the search space identification number (e.g., called "search space ID, SS ID").

[0124] - The drop rule does not apply to secondary cells. In other words, the drop rule applies to primary cells.

[0125] [DL Burst Detection]

[0126] For DL ​​burst detection, the following three phases have been discussed, for example. Figure 7 This is an example representing three stages.

[0127] Phase A: Detection of DL burst

[0128] Phase B: After detecting a DL burst and arriving at the time slot ( Figure 7 Before the boundary of time slot #0 (partial slot)

[0129] Phase C: After detecting a DL burst and arriving at the time slot ( Figure 7 After the boundary of time slot #0 (the entire time slot)

[0130] For example, the use of Group Common PDCCH (GC-PDCCH) to detect DL bursts has been studied. The base station, for instance, transmits the GC-PDCCH at the leading edge of a DL burst, and the terminal detects the GC-PDCCH during pre-defined PDCCH monitoring opportunities. If the GC-PDCCH is successfully detected, the terminal recognizes the transmission of the DL burst (in other words, the DL burst is detected). Furthermore, the inclusion of information such as the available LBT subbands (also known as "LBT bandwidth") or the slot format within the channel occupancy time (COT) has been investigated in the GC-PDCCH.

[0131] [CORESET and Search Space]

[0132] Version 15NR specifies, for example, the number of regions, i.e., control resource sets (CORESET) or search spaces (SS), that can be allocated downlink control channels to terminals.

[0133] CORESET: 3 (per bandwidth part, BWP)

[0134] SS: 10 (per BWP)

[0135] For example, the bandwidth of the BWP is set to 80MHz, and the bandwidth of the frequency band (e.g., referred to as "LBT subband") for carrier sensing (e.g., LBT) by the terminal (or base station) is set to 20MHz. For example, if there are 4 LBT subbands in the BWP and a CORESET is configured in each LBT subband (in other words, if a dedicated CORESET is configured in each LBT subband), the terminal is set with 4 CORESETs, which exceeds the number specified above (3).

[0136] Therefore, in NR-U, the following was agreed upon: when CORESET is configured in a manner that converges within LBT subbands (in other words, in a closed manner), the same CORESET and the SS associated with the CORESET may be configured in multiple subbands, regardless of the number specified above (e.g., 3).

[0137] Figure 8 This represents an example of configuring the same CORESET and SS in multiple (e.g., 4) LBT subbands.

[0138] [Maximum BD count, maximum CCE count, and SS]

[0139] As mentioned above, in NR-U, it was agreed that the same CORESET and SS could be configured on multiple subbands.

[0140] Furthermore, in NR-U, it was agreed that, in order to reduce the complexity of UE implementation, the maximum number of BDs and the maximum number of CCEs specified in version 15NR would not be increased. On the other hand, for example, it is possible to envision a situation where LBT subbands cannot be used due to LBT failure (e.g., referred to as "LBT failure"), and SSs would be set in multiple LBT subbands respectively.

[0141] Under the aforementioned limitations of maximum BD number and maximum CCE number, if SS is set to multiple LBT subbands, the efficiency of PDCCH candidate configuration may decrease.

[0142] Figure 9 This represents a configuration example for PDCCH monitoring opportunities.

[0143] exist Figure 9 In the example shown, the maximum number of BDs set for the terminal is 44. Furthermore, in Figure 9In this explanation, for simplicity, the maximum number of BDs is considered, but the maximum number of CCEs is not. In subsequent explanations, the expression "considering..." can be replaced with "based on..." or "using...", and the expression "not considering..." can be replaced with "not based on..." or "not using...". Additionally, in... Figure 9 In this example, four LBT subbands (e.g., LBT subband #0 to LBT subband #3) are described, but the number of LBT subbands is not limited to four and can be other numbers. Furthermore, in Figure 9 In this process, PDCCH monitoring opportunities with a BD count of 11 times were set for sub-bands #0 to #3 respectively.

[0144] For example, in Figure 9 In (a), setting it to LBT results in LBT failure for subbands #0 to #2, while subband #3 becomes available. Additionally, in Figure 9 In (b), setting it to LBT results in subbands #0 to #3 being available.

[0145] For example, in Figure 9 In case (a), the number of BDs in a terminal's effective PDCCH monitoring opportunity (e.g., SS#1 of subband #3) is 11. Figure 9 In (a), the number of BDs (11 times) set for the terminal is below the maximum number of BDs (e.g., 44 times). Therefore, in Figure 9 In (a), through the settings of the SS, for example, a terminal can be configured in subband #3 to be a different SS than SS#1 and to send and receive PDCCH.

[0146] On the other hand, for example, in Figure 9 In case (b), the number of BDs in the effective PDCCH monitoring opportunities for the terminal (e.g., SS#1 for each of subbands #0 to #3) is 44. Figure 9 In (b), the BD count set for the terminal (44 times) has reached the maximum BD count (e.g., 44 times). Therefore, in Figure 9 In (b), for the terminal, it is not possible to further configure other SSs that are different from SS#1.

[0147] In NR, for example, each SS can be associated with a different type or purpose of PDCCH, allowing for differentiated use of SS based on purpose, thereby improving the efficiency of PDCCH transmission and reception. However, for example, in Figure 9 In the example shown in (b), it is not possible to configure multiple SS in each LBT subband, which may prevent the efficiency of PDCCH configuration from being improved.

[0148] Thus, in DL burst detection of NR-U, there is still room for research regarding the method of PDCCH transmission. Therefore, in one embodiment of the present invention, a method for DL ​​burst detection in NR-U and for improving the efficiency of PDCCH transmission is described.

[0149] (Implementation Method 1)

[0150] [Overview of Communication Systems]

[0151] One aspect of the communication system of the present invention includes, for example, […]. Figure 10 and Figure 12 The base station 100 shown (e.g., gNB), and Figure 11 and Figure 13 The terminal 200 (e.g., UE) shown is shown.

[0152] Figure 10 This is a block diagram illustrating a structural example of a base station 100 according to one embodiment of the present invention. Figure 10 In the base station 100 shown, the scheduling unit 104 determines, based on information related to at least one of the number of BDs (Digital Bullet Indicators) for the downlink control channel signal and the number of resources (e.g., number of Channel Estimated Components) for the channel estimation, a configuration method (in other words, PDCCH monitoring opportunity) for the downlink control channel signal during at least one of the following periods: a first period (e.g., phase A) before the carrier sensing (e.g., LBT) timing (in other words, the timing when the DL burst in the terminal 200 is detected, i.e., the detection timing). The transmitting unit 108 transmits the downlink control channel signal based on the determined configuration method.

[0153] Figure 11 This is a block diagram illustrating a structural example of a portion of a terminal 200 according to one embodiment of the present invention. Figure 11 In the terminal 200 shown, the receiving control unit 205 determines the reception opportunity (e.g., PDCCH monitoring opportunity) of the downlink control channel signal during at least one of a first period (e.g., phase A) before the detection opportunity of a downlink burst (DL burst) and a second period (e.g., phase B or phase C) after the detection opportunity, based on information related to at least one of the maximum number of BDs with respect to the downlink control channel signal and the number of resources (e.g., number of CCEs) estimated for the channel. The receiving unit 201 receives the downlink control channel signal at the determined reception opportunity.

[0154] [Base station structure]

[0155] Figure 12 This is a block diagram illustrating a structural example of a base station 100 according to one embodiment of the present invention. Figure 12In this system, base station 100 includes a receiving unit 101, a demodulation / decoding unit 102, a channel state estimation unit 103, a scheduling unit 104, a control information retention unit 105, a data / control information generation unit 106, an encoding / modulation unit 107, and a transmitting unit 108.

[0156] The receiving unit 101 receives the signal transmitted from the terminal 200 via the antenna, performs reception processing such as down-conversion or A / D (Analog / Digital) conversion on the received signal, and outputs the received signal after reception processing to the demodulation / decoding unit 102 and the channel state estimation unit 103.

[0157] The demodulation / decoding unit 102 demodulates and decodes the received signal input from the receiving unit 101, and outputs the decoding result to the scheduling unit 104.

[0158] The channel state estimation unit 103 estimates the channel state (in other words, carrier sensing or LBT) based on the received signal input from the receiving unit 101. For example, the channel state estimation unit 103 can determine whether the channel state is busy or idle. The channel state estimation unit 103 outputs information indicating the determined channel state to the scheduling unit 104.

[0159] The scheduling unit 104 generates, for example, information related to the setting of the PDCCH for the terminal 200 (hereinafter referred to as "PDCCH setting information"), and outputs it to the control information retention unit 105. In addition, the scheduling unit 104 outputs signaling information containing the PDCCH setting information to the data / control information generation unit 106.

[0160] Furthermore, the scheduling unit 104 performs, for example, scheduling (e.g., allocation) of the PDCCH for each terminal 200. For example, the scheduling unit 104 may determine (in other words, decide) each stage of the DL burst based on information representing the channel state input from the channel state estimation unit 103. Figure 7 The scheduling unit 104 monitors the PDCCH opportunities in each terminal 200 during phases A, B, and C, and schedules the PDCCH for each terminal 200 based on the determination results. Based on the scheduling results, the scheduling unit 104 instructs the data / control information generation unit 106 to generate data or control information. Furthermore, the scheduling unit 104 outputs scheduling information containing the scheduling results to the encoding / modulation unit 107.

[0161] In addition, the scheduling unit 104 may, for example, instruct the data / control information generation unit 106 to generate data or control information based on the decoding result input from the demodulation / decoding unit 102.

[0162] For example, the PDCCH settings may include settings such as CORESET settings or SS settings.

[0163] The control information retention unit 105 retains, for example, control information input from the scheduling unit 104 (e.g., PDCCH setting information). The control information retention unit 105 may output the retained information to each structural unit of the base station 100 (e.g., the scheduling unit 104) as needed.

[0164] The data / control information generation unit 106 generates data or control information according to the instructions from the scheduling unit 104, and outputs a signal containing the generated data or control information to the encoding / modulation unit 107. The control information may, for example, include signaling information input from the scheduling unit 104.

[0165] The encoding / modulation unit 107 encodes and modulates the signal input from the data / control information generation unit 106 based on the scheduling information input from the scheduling unit 104, and outputs the modulated signal (symbol sequence) to the transmission unit 108.

[0166] The transmitting unit 108 performs transmission processing such as D / A (Digital / Analog) conversion, up-conversion, or amplification on the signal input from the encoding / modulation unit 107, and transmits the wireless signal obtained through the transmission processing from the antenna to the terminal 200.

[0167] [Terminal Structure]

[0168] Figure 13 This is a block diagram illustrating a structural example of a terminal 200 according to one embodiment of the present invention. Figure 13 In the terminal 200, there are receiving units 201, demodulation / decoding units 202, DL transmission detection units 203, control information retention units 204, receiving control units 205, transmission control units 206, data generation units 207, encoding / modulation units 208, and transmission units 209.

[0169] The receiving unit 201 performs reception processing such as down-conversion or A / D conversion on the received signal received via the antenna, and outputs the received signal to the demodulation / decoding unit 202.

[0170] The demodulation / decoding unit 202 demodulates and decodes the data or control information contained in the received signal input from the receiving unit 201, and outputs the decoding result to the transmission control unit 206. Additionally, for example, the demodulation / decoding unit 202 outputs the signaling information contained in the decoding result to the control information retention unit 204.

[0171] Additionally, for example, the demodulation / decoding unit 202 demodulates and decodes the PDCCH contained in the received signal based on the information input from the receiving control unit 205, and outputs the decoding result of the PDCCH to the DL transmission detection unit 203.

[0172] The DL transmission detection unit 203 detects DL bursts based on the decoding result of the PDCCH input from the demodulation / decoding unit 202. The DL transmission detection unit 203 outputs DL burst information indicating the detection result of the DL burst to the reception control unit 205. The DL burst information may include, for example, LBT information indicating the resources available to the terminal 200 (e.g., LBT subbands), or information such as the channel occupancy time (COT) length.

[0173] The control information retention unit 204 retains the signaling information (e.g., PDCCH setting information) input from the demodulation / decoding unit 202, and outputs the retained information to each structural unit (e.g., the receiving control unit 205 or the transmitting control unit 206) as needed.

[0174] The receiving control unit 205 determines a PDCCH monitoring opportunity based on the DL burst information input from the DL transmission detection unit 203 and the PDCCH setting information input from the control information retention unit 204. The receiving control unit 205 outputs PDCCH monitoring opportunity information indicating the determination result to the demodulation / decoding unit 202.

[0175] Based on the decoding result input from the demodulation / decoding unit 202 and the information input from the control information retention unit 204, the transmission control unit 206 instructs the data generation unit 207 to generate data.

[0176] The data generation unit 207 generates transmission data (e.g., PUSCH) based on the data generation instruction input from the transmission control unit 206 and outputs it to the encoding / modulation unit 208.

[0177] The encoding / modulation unit 208 encodes and modulates the transmission data input from the data generation unit 207, and outputs the modulated signal to the transmission unit 209.

[0178] The transmitting unit 209 performs transmission processing such as D / A conversion, up-conversion, or amplification on the signal input from the encoding / modulation unit 208, and transmits the wireless signal obtained through the transmission processing to the base station 100 from the antenna.

[0179] [Operations of base station 100 and terminal 200]

[0180] This section describes an example of the operation of a base station 100 and a terminal 200 with the above structure.

[0181] Figure 14 This is a sequence diagram representing an example of the actions of base station 100 and terminal 200.

[0182] Base station 100 performs channel state estimation (e.g., carrier sensing or LBT) (ST101).

[0183] Base station 100 sets PDCCH monitoring opportunities (ST102) for terminal 200. For example, base station 100 may set PDCCH monitoring opportunities for terminal 200 based on the results of channel state estimation (e.g., busy state or idle state), information related to the LBT subband set for terminal 200, or information such as the number of BDs or CCEs set for terminal 200.

[0184] Base station 100 transmits downlink signals (ST103) to terminal 200. These downlink signals may include, for example, DL burst information, PDCCH configuration information, or PDCCH signals (e.g., scheduling information). This information may be contained within the same signal or within different signals. For example, DL burst information may be contained within the Group Common PDCCH (GC-PDCCH). Additionally, PDCCH configuration information may be contained within signaling information.

[0185] Terminal 200 performs DL burst detection (ST104) for example based on signals transmitted from base station 100 (e.g., GC-PDCCH).

[0186] Terminal 200 sets PDCCH monitoring opportunities for terminal 200 (ST105). For example, terminal 200 may set PDCCH monitoring opportunities based on DL burst detection results, information related to LBT subbands set for terminal 200, or information such as BD number or CCE number set for terminal 200.

[0187] Terminal 200, for example, receives (e.g., blindly decodes) a PDCCH (ST106) destined for terminal 200 during a pre-set PDCCH monitoring opportunity. The PDCCH may contain, for example, information related to resources scheduled (in other words, allocated) for terminal 200.

[0188] Base station 100 and terminal 200 communicate data (e.g., uplink data or downlink data) based on resources allocated to terminal 200 (ST107).

[0189] [PDCCH Monitoring Opportunity Decision-Making Method]

[0190] This describes an example of the method for determining PDCCH monitoring opportunities in the scheduling unit 104 of base station 100. Additionally, the reception control unit 205 of terminal 200 can determine PDCCH monitoring opportunities based on the same determination method as the scheduling unit 104.

[0191] <Decision Method 1>

[0192] In decision method 1, if the number of BDs or CCEs set for terminal 200 exceeds a threshold (e.g., an upper limit such as the maximum number of BDs or CCEs), base station 100 determines the search space (SS) configured in the resources based on the priority of the LBT subbands. For example, base station 100 drops SSs based on the priority of each LBT subband. In other words, base station 100 sets the number of BDs or CCEs set for terminal 200 below the threshold by dropping SSs according to LBT subbands.

[0193] The drop rules for discarding SS by LBT subband can be added to the drop rules specified in version 15NR and applied.

[0194] For example, in the discard rule for method 1, SSs are first discarded in descending order of their SS IDs. In other words, the discard rule allocates SSs to resources in ascending order of their SS IDs.

[0195] Next, for example, in the case of multiple SSs with the same SS ID, when the number of BDs or CCEs of each SS exceeds a threshold (e.g., the maximum number of BDs or the maximum number of CCEs), base station 100 discards the SS based on the priority of the LBT subband. For example, base station 100 may discard SSs in ascending order of LBT subband priority. In other words, base station 100 may allocate SSs to resources in descending order of LBT subband priority.

[0196] Figure 15 This represents an example of the action that determines method 1.

[0197] In addition, Figure 15 In this explanation, for the sake of simplicity, the number of BDs is considered but the number of CCEs is not considered. For example, not limited to the case where the number of BDs set for terminal 200 exceeds the maximum number of BDs, base station 100 may decide on the SS based on the discard rule of decision method 1 if at least one of the number of BDs and the number of CCEs exceeds a threshold (e.g., one of the maximum number of BDs and the maximum number of CCEs).

[0198] exist Figure 15 In the example shown, the maximum number of BDs set for terminal 200 is 44.

[0199] In addition, Figure 15 In this example, four LBT subbands (e.g., LBT subband #0 to LBT subband #3) are described, but the number of LBT subbands is not limited to four and can be other numbers. Furthermore, in Figure 15In the LBT subbands, for SS#1 and SS#2, the priority is in the order of subband #0, subband #1, subband #2, and subband #3 from highest to lowest (in other words, subband #0 has the highest priority, and subband #3 has the lowest priority). Additionally, in Figure 15 For example, in each subband's SS (e.g., SS#1 and SS#2), the ID of SS#1 is lower than the ID of SS#2. Therefore, SS#1 will be configured in resources with priority over SS#2.

[0200] Additionally, the number of BDs configured in the SS of each sub-band is set to 8. However, the number of BDs in the SS is not limited to 8; it can be any other number.

[0201] For example, in Figure 15 In (a), the result of LBT is that the terminal 200 can utilize the four LBT subbands, subband #0 to subband #3.

[0202] For example, in Figure 15 In (a), regarding SS#1, which has a higher priority than SS#2, if SS#1 is configured in LBT subbands #0 to #3 respectively, the number of BDs set for terminal 200 becomes 32, which is below the maximum number of BDs (44). Therefore, SS#1 is configured in the available resources of LBT subbands #0 to #3 (in other words, it will not be discarded).

[0203] In addition, Figure 15 In (a), regarding SS#2, which has a lower priority than SS#1, if SS#2 is configured in LBT subbands #0 to #3 in addition to SS#1, the number of BDs set for terminal 200 becomes 64, which exceeds the maximum number of BDs (44). Therefore, base station 100, for example, based on the priority of subbands #0 to #3, configures SS#2 in resources in subband #0, and discards SS#2 in subbands #1, #2, and #3. Through this discarding, the number of BDs set for terminal 200 becomes 40, which is below the maximum number of BDs (44).

[0204] On the other hand, Figure 15 In (b), the result of LBT is in the following state: terminal 200 can utilize the three LBT subbands, subband #1 to subband #3, but cannot utilize subband #0 due to LBT failure.

[0205] exist Figure 15 In (b), base station 100 may count, for example, the number of BDs (e.g., 16 times) of SS set to unusable subband #0 from the number of BDs for terminal 200.

[0206] For example, in Figure 15 In (b), regarding SS#1, which has a higher priority than SS#2, if SS#1 is configured in LBT subbands #1 to #3 respectively, the number of BDs set for terminal 200 becomes 24, which is below the maximum number of BDs (44). Therefore, SS#1 is configured in the available resources of LBT subbands #1 to #3 (in other words, it will not be discarded).

[0207] In addition, Figure 15 In (b), regarding SS#2, which has a lower priority than SS#1, if SS#2 is configured in subbands #1 to #3 in addition to SS#1, the number of BDs set for terminal 200 becomes 48, which exceeds the maximum number of BDs (44). Therefore, base station 100, for example, based on the priority of subbands #1 to #3, configures SS#2 in resources in subbands #1 and #2, and discards SS#2 in subband #3. Through this discarding, the number of BDs set for terminal 200 becomes 40, which is below the maximum number of BDs (44).

[0208] Here, if the discard rule of decision method 1 is not applied (for example, under the discard rule specified in version 15NR), then regardless of... Figure 15 When (a), or at Figure 15 In (b), SS#1 is configured in resources in each LBT subband, while SS#2 is discarded. In other words, the same SS (e.g., SS#2) that should be configured in multiple LBT subbands will not be configured in resources in any of the aforementioned LBT subbands.

[0209] In contrast, according to decision method 1, SS#2 is... Figure 15 The resources configured in subband #0 in (a) are in Figure 15 Resources configured in subbands #1 and #2 in (b). In other words, in decision method 1, based on the priority among multiple LBT subbands, it is decided whether to configure the same SS (e.g., SS#2) set in the aforementioned multiple LBT subbands as a resource or discard it. For example, as Figure 15 (a) and Figure 15 As shown in (b), SS#2 configured in LBT subbands can be configured as resources in a portion of the LBT subbands and discarded in the remaining LBT subbands. According to this discarding rule, base station 100 can increase the number of SS configured for terminal 200, thereby improving the PDCCH transmission and reception efficiency.

[0210] For example, the discard rule of method 1 is applied when... Figure 7 In the case of stage A shown, it can be applied to all LBT subbands (e.g., with...). Figure 15(same as (a)). Additionally, the discard rule for method 1 is applied when... Figure 7 The cases shown in stages B and C can be applied to all LBT subbands (e.g., with...). Figure 15 (same as (a)), and can also be applied to the LBT subbands available to terminal 200 based on LBT results (e.g., with Figure 15 (same as (b)).

[0211] When the discard rule of method 1 is applied to all LBT subbands (e.g., when applied to phase A), the SS configuration does not change due to the LBT result. Therefore, it is possible to simplify the SS determination process in base station 100, PDCCH scheduling, or reception actions in terminal 200.

[0212] Furthermore, when the discard rule of decision method 1 is applied to the LBT subbands available to terminal 200 (e.g., stage B or stage C), unusable LBT subbands can be excluded based on the LBT decision, for example, from the count value of the BD number. Therefore, the number of PDCCH candidates actually configured can be increased, thereby improving the efficiency of resource utilization.

[0213] In addition, in method 1, the priority of the LBT subband can be notified to the terminal 200 by the base station 100 via signaling information, or it can be specified in the specifications (or standards). For example, the priority of the LBT subband with a lower subband number can be set to a higher priority, or it can be set to a random priority that varies according to the terminal 200.

[0214] In addition, the priority of LBT subbands can also be different based on SS. By using LBT subband priorities that differ based on SS, for example, it is easy to configure SS in different LBT subbands, which can reduce the possibility of PDCCH monitoring opportunities conflicting (in other words, blocking) between SS for PDCCH resources.

[0215] Furthermore, the priority of LBT subbands can also differ between terminals 200. By using LBT subband priorities that differ per terminal 200, for example, the possibility that the LBT subbands configured for PDCCH differ between terminals 200 is increased. Therefore, the possibility of PDCCH monitoring opportunity conflicts (in other words, restrictions) between terminals 200 can be reduced.

[0216] In addition, Figure 15 The text describes the scenario where the SS is set in each LBT subband, but the SS does not necessarily need to be set in every LBT subband set for the terminal 200; it can be set in a subset of LBT subbands. Even in this case, the base station 100 can determine whether to discard a component based on the priority of a subset of LBT subbands.

[0217] Thus, according to decision method 1, by applying the drop rules based on the priority of LBT subbands, the number of SS (in other words, PDCCH monitoring opportunities) that can be configured in LBT subbands is increased, thereby improving resource utilization efficiency.

[0218] [A variation of method 1]

[0219] Furthermore, in Method 1, for example, the following method is described: after determining the SS ID, the priority of the LBT subband is determined. In other words, the following method is described: when there are multiple SSs with the same SS ID, if the number of BDs or CCEs exceeds a threshold (e.g., the maximum number of BDs or the maximum number of CCEs), the SSs are discarded in ascending order of priority based on the priority of the LBT subbands. However, this method is not the only option.

[0220] For example, in a variation of method 1, the method can also be applied by reversing the order of determining the SS ID and the priority of the LBT subband. In other words, for example, the method can also determine the SS ID after determining the priority of the LBT subband. For example, base station 100 can first discard SSs in ascending order of LBT subband priority, and if there are multiple SSs in the same LBT subband, discard them in descending order of SS ID.

[0221] Figure 16 This represents an action example that determines a variation of method 1. Furthermore, Figure 16 The conditions in the text (e.g., maximum BD number, BD number of each SS, LBT subband number, LBT subband priority, or LBT results, etc.) and Figure 15 The examples are the same.

[0222] exist Figure 16 In (a), base station 100 first configures SS in the resources of the LBT subband according to the LBT subband priority from high to low (e.g., in the order of subband #0, subband #1, subband #2, subband #3). Figure 16 In (a), for example, if both SS#1 and SS#2 are configured in subband #2, the number of BDs set for terminal 200 becomes 48, which exceeds the maximum number of BDs (44). Therefore, base station 100 configures SS#1 (the SS with the lower SS ID, which has higher priority) in resources in subband #2 and discards SS#2 (which has the higher SS ID). Through this discarding, the number of BDs set for terminal 200 becomes 40, which is below the maximum number of BDs (44). Furthermore, in Figure 16 In (a), SS#1 and SS#2 of the lower priority subband #3 are both discarded.

[0223] exist Figure 16 In case (b), also utilize with Figure 16 The same process as in case (a) is used to configure SS resources in each LBT subband. Figure 16 In case (b), discard SS#2 of subband #3.

[0224] Thus, in a variation of decision method 1, where the order of SS ID determination and LBT subband priority determination is reversed compared to decision method 1, the number of SSs (in other words, PDCCH monitoring opportunities) that can be configured in LBT subbands increases, thereby improving resource utilization efficiency. Furthermore, in the variation of decision method 1, based on this discarding rule, for example, compared to decision method 1, scheduling can be performed to concentrate PDCCH monitoring opportunities on a portion of the LBT subbands.

[0225] The above illustrates a variation of method 1.

[0226] Furthermore, dropping is not limited to units of SS (Summoning Rank) but can also be done on a per-PDCCH candidate basis. For example, priorities can be assigned to aggregation levels (ALs), and SSs can be configured in order of higher-priority ALs until the maximum BD (Block Rank) or maximum CCE (Cracked Execution Rank) is reached. By configuring this SS, PDCCH candidates can be allocated at a finer granularity. This increases the opportunity for PDCCH monitoring, thereby improving resource utilization efficiency.

[0227] Additionally, for example, the dropping of PDCCH candidates can be applied in conjunction with the priority of LBT subbands. For example, when applying the dropping rule of decision method 1 described above, dropping of PDCCH candidates can be performed instead of dropping of SS. Alternatively, the priority of LBT subbands can be omitted, and dropping of PDCCH candidates can be applied to all LBT subbands. In the case of dropping of PDCCH candidates to all LBT subbands, the base station 100 can, for example, after configuring SSs based on SS ID determination, drop SSs based on AL priority when there are multiple SSs with the same SS ID, targeting all LBT subbands. Through this dropping, for example, PDCCH candidates and PDCCH monitoring opportunities can be distributed among LBT subbands for scheduling, thereby reducing the possibility of PDCCH monitoring opportunity conflicts.

[0228] <Decision Method 2>

[0229] In decision method 2, if the number of LBT subbands with set PDCCH monitoring opportunities exceeds a threshold (e.g., the maximum number of LBT subbands), base station 100 determines the SS configured in the resource based on the priority of the LBT subbands. For example, base station 100 discards SSs based on the priority of each LBT subband.

[0230] Dropping SS based on LBT subband number can be applied, for example, before the drop rules specified in version 15NR.

[0231] For example, in the decision-making method 2 for discarding, if the number of LBT subbands set for terminal 200 exceeds a threshold (e.g., the maximum number of LBT subbands), base station 100 discards SSs based on the priority of the LBT subbands. For example, base station 100 may discard SSs set in LBT subbands in ascending order of LBT subband priority. In other words, base station 100 may allocate SSs set in LBT subbands to resources in descending order of LBT subband priority.

[0232] After determining the LBT subband number-based discarding method 2, for example, if the number of BDs or CCEs in each SS exceeds a threshold (e.g., the maximum number of BDs or the maximum number of CCEs), similarly to version 15NR, base station 100 may discard SSs in descending order of SS ID.

[0233] Figure 17 This represents an example of the action that determines method 2.

[0234] In addition, Figure 17 In this explanation, for the sake of simplicity, the number of BDs is considered but the number of CCEs is not considered. For example, not limited to the case where the number of BDs set for terminal 200 exceeds the maximum number of BDs, if at least one of the number of BDs and the number of CCEs exceeds a threshold (e.g., one of the maximum number of BDs and the maximum number of CCEs), base station 100 may determine the SS based on the discard rule of decision method 2.

[0235] exist Figure 17 In this example, four LBT subbands (e.g., LBT subband #0 to LBT subband #3) are described, but the number of LBT subbands is not limited to four and can be other numbers. Furthermore, in Figure 17 In the LBT subbands, for SS#1 and SS#2, the priority of the subbands is in the order of subband #0, subband #1, subband #2, and subband #3 from high to low (in other words, subband #0 has the highest priority and subband #3 has the lowest priority).

[0236] In addition, Figure 17 In the example shown, for SS#1 and SS#2, the maximum number of LBT subbands set for terminal 200 is 2.

[0237] Additionally, the number of BDs configured in the SS of each sub-band is set to 8. However, the number of BDs in the SS is not limited to 8; it can be any other number.

[0238] For example, in Figure 17 In (a), the result of LBT is that the terminal 200 can utilize the four LBT subbands, subband #0 to subband #3.

[0239] exist Figure 17 In (a), the number of LBT subbands set for SS#1 and SS#2 both exceed the maximum number of LBT subbands (2). Therefore, base station 100, for example, based on the priority of subbands #0 to #3, configures SS#1 and SS#2 in resources in subbands #0 and #1, and discards SS#1 and SS#2 in subbands #2 and #3. Through this discarding, the number of BDs set for terminal 200 becomes 32, which is below the maximum number of BDs (44).

[0240] On the other hand, Figure 17 In (b), the result of LBT is in the following state: terminal 200 can utilize the three LBT subbands, subband #1 to subband #3, but cannot utilize subband #0 due to LBT failure.

[0241] exist Figure 17 In (b), the number of LBT subbands set for SS#1 and SS#2 both exceed the maximum number of LBT subbands (2). Therefore, based on the priority of subbands #1 to #3, base station 100 allocates SS#1 and SS#2 to resources in subbands #1 and #2, and discards SS#1 and SS#2 in subband #3. Through this discarding, the number of BDs set for terminal 200 becomes 32, which is below the maximum number of BDs (44).

[0242] Additionally, base station 100 can also be used in Figure 17 (a) and Figure 17 In (b) of both cases, after discarding SS based on the maximum LBT subband number, for example, the discarding rules of version 15NR are applied (e.g., discarding based on the BD number or CCE number).

[0243] For example, the discard rule for method 2 is applied when... Figure 7 In the case of stage A shown, it can be applied to all LBT subbands (e.g., with...). Figure 17 (same as (a)). Additionally, the discard rule for method 2 is applied when... Figure 7 The cases shown in stages B and C can be applied to all LBT subbands (e.g., with...). Figure 17(same as (a)) can also be applied to LBT subbands available to terminal 200 (e.g., with Figure 17 (same as (b)).

[0244] When the discard rule of method 2 is applied to all LBT subbands (e.g., when applied to phase A), the SS configuration is not changed due to the result of LBT. Therefore, the SS determination process in base station 100, PDCCH scheduling, or reception operation in terminal 200 can be simplified.

[0245] Furthermore, when the discard rule of decision method 2 is applied to LBT subbands available to terminal 200 (e.g., stage B or stage C), unusable LBT subbands can be excluded based on the LBT decision, thereby increasing the number of actually configured PDCCH candidates and improving resource utilization efficiency.

[0246] In addition, in method 2, at least one of the maximum number of LBT subbands and the priority of the LBT subbands can be notified to the terminal 200 by the base station 100 via signaling information, or it can be specified in the specification (or standard). For example, the priority of the LBT subband with the lower subband number can be set to high priority, or it can be set to a random priority that varies according to the terminal 200.

[0247] Alternatively, at least one of the maximum number and priority of LBT subbands can differ based on SS. By using a maximum number and priority of LBT subbands that differ based on SS, for example, it is easy to configure SSs in different LBT subbands, which can reduce the possibility of PDCCH monitoring opportunities conflicting (in other words, being limited) between SSs for PDCCH resources.

[0248] Furthermore, at least one of the maximum number and priority of LBT subbands may differ between terminals 200. By using a maximum number and priority of LBT subbands that differ per terminal 200, for example, the possibility of different LBT subbands configured for PDCCH between terminals 200 is increased. Therefore, the possibility of PDCCH monitoring opportunity conflicts (in other words, restrictions) between terminals 200 can be introduced.

[0249] Additionally, unlike the dropping rules in version 15NR (e.g., dropping rules based on the maximum BD count or maximum CCE count), the dropping rules for method 2 can also be applied to CSS. In the dropping rules of version 15NR, the decision to drop SS is made, for example, based on the BD count or CCE count for each UE. The count value of the BD count or CCE count is, for example, the total value of CSS and USS. Therefore, for example, in a dropping rule that drops SS by including CSS, whether CSS is dropped will vary depending on the UE.

[0250] Here, we assume that the CSS is shared among UEs. If whether the CSS is discarded varies depending on the UE, a situation arises where the PDCCH sent in the CSS is received by one UE but not by others. In this scenario, the scheduling of base station 100 would become complex. Therefore, it is difficult to imagine applying, for example, the discarding rules of version 15NR to the CSS.

[0251] On the other hand, during DL burst transmission, the LBT subbands available to terminal 200 are notified to terminal 200 by base station 100. Therefore, the discarding rule of decision method 2 can, for example, determine the SS configuration (in other words, SS discarding) based on the number of LBT subbands available to terminal 200. Thus, in decision method 2, for example, by unifying the maximum number of LBT subbands and the priority settings of LBT subbands among terminals 200, the discarding of SS (e.g., CSS) can be determined among terminals 200 based on the same determination criteria. Therefore, the discarding rule of decision method 2 can also be applied to CSS.

[0252] In addition, Figure 17 The text describes the scenario where SS is set in each LBT subband, but SS does not need to be set in every LBT subband set for terminal 200; it can be set in a subset of LBT subbands. Even in this case, base station 100 can determine whether to discard a component based on the number and priority of a subset of LBT subbands.

[0253] Thus, according to decision method 2, by applying the discard rules based on the number and priority of LBT subbands, the number of SS (in other words, PDCCH monitoring opportunities) that can be configured in LBT subbands is increased, thereby improving resource utilization efficiency.

[0254] The above explains decision method 1 and decision method 2.

[0255] In this embodiment, the base station 100 and the terminal 200 determine the PDCCH monitoring opportunities in each LBT sub-band based on the priority of the LBT sub-bands (frequency resources) set for the terminal 200 (in other words, the PDCCH configuration method in the base station 100). Through this setting, the base station 100 and the terminal 200 can, for example, set PDCCH monitoring opportunities (e.g., parameters such as SS or BD number and CCE number) for multiple LBT sub-bands respectively, thus improving the efficiency of PDCCH configuration.

[0256] Furthermore, in this embodiment, the base station 100 and the terminal 200 determine, for example, the PDCCH monitoring opportunities (in other words, the PDCCH configuration method) within at least one of the following two periods based on information related to at least one of the maximum BD number and the maximum CCE number: phase A (the period before the time when the DL burst is detected), and phases B and C (the period after the time when the DL burst is detected). For example, the base station 100 and the terminal 200 determine the LBT subbands that are the targets for setting PDCCH monitoring opportunities according to each phase in DL burst detection, and determine the setting of PDCCH monitoring opportunities for the determined LBT subbands. Through this setting, the base station 100 and the terminal 200 can set PDCCH monitoring opportunities suitable for each phase in DL burst detection, thus improving the efficiency of PDCCH configuration.

[0257] Therefore, according to this embodiment, for example, the transmission efficiency of DL signals in NR-U can be improved.

[0258] (Implementation Method 2)

[0259] Imagine the various stages associated with DL burst detection (e.g., Figure 7 The configuration of the desired PDCCH monitoring opportunities differs in stages A, B, and C shown.

[0260] For example, Phase A is the period before the detection of DL bursts; therefore, the availability of each LBT subband will vary depending on the LBT results. Thus, in Phase A, PDCCH monitoring opportunities can be configured across all LBT subbands. Furthermore, to begin transmission earlier in Phase A, it is ideal to have finer-grained PDCCH monitoring opportunities in the time domain (in other words, configuring PDCCH monitoring opportunities with short periods).

[0261] On the other hand, for example, phase C is the period after the detection of a DL burst, so PDCCH monitoring opportunities may not be configured across all LBT subbands. Furthermore, in phase C, when PDSCH scheduling does not require short cycles, the granularity of PDCCH monitoring opportunities in the time domain can be coarser.

[0262] In addition, the dynamic switching of PDCCH monitoring opportunities can complicate scheduling processes in base stations or reception processes in terminals.

[0263] Therefore, this embodiment describes a method that dynamically switches PDCCH monitoring opportunities while suppressing the complexity of scheduling processing in the base station and receiving processing in the terminal.

[0264] [Structure of base stations and terminals]

[0265] The structure of the base station and terminal in this embodiment is the same as that of the base station 100 and terminal 200 in embodiment 1.

[0266] In this embodiment, the scheduling unit 104 of the base station 100 determines the PDCCH monitoring stage based on the stage in DL burst detection, for example. Furthermore, based on the determined PDCCH monitoring stage, the scheduling unit 104 changes the method for determining the PDCCH monitoring opportunity in the LBT subband. Next, the scheduling unit 104 determines the PDCCH monitoring opportunity (e.g., SS) in each LBT subband, for example, based on the method for determining the PDCCH monitoring opportunity.

[0267] "PDCCH monitoring phase" is, for example, a period derived from classifying the various phases of DL burst detection based on a method for determining PDCCH monitoring opportunities. For example, regarding... Figure 7 The diagram shows stages A, B, and C. Stages A and B are classified as "PDCCH Monitoring Stage 1," and stage C is classified as "PDCCH Monitoring Stage 2." For example, PDCCH monitoring stages can also be defined in time slots (respectively...). Figure 7 (Time slot #0 and time slot #1 in the middle).

[0268] In this embodiment, the receiving control unit 205 of the terminal 200, like the scheduling unit 104, determines the PDCCH monitoring stage based on the stage in DL burst detection, and changes the PDCCH monitoring opportunity determination method in the LBT subband based on the determined PDCCH monitoring stage.

[0269] [PDCCH Monitoring Opportunity Decision-Making Method]

[0270] This describes an example of the method for determining PDCCH monitoring opportunities in the scheduling unit 104 of base station 100. Additionally, the reception control unit 205 of terminal 200 can determine PDCCH monitoring opportunities based on the same determination method as the scheduling unit 104.

[0271] As an example, as described above, based on the viewpoint of switching PDCCH monitoring opportunities, base station 100 classifies stages into two PDCCH monitoring stages. For example, base station 100 classifies stages A and B into PDCCH monitoring stage 1 (hereinafter also referred to as "Stage 1"), and classifies stage C into PDCCH monitoring stage 2 (hereinafter also referred to as "Stage 2"). In other words, stage A and stage B, which are contained in the same time slot as stage A, are classified into stage 1, and stage C, which is contained in a different time slot than stage A, is classified into stage 2. Furthermore, "classification" can also be used interchangeably with "correspondence" or "association".

[0272] Figure 18 This describes a setting example of the PDCCH monitoring opportunity in this embodiment.

[0273] exist Figure 18 In this example, four LBT subbands are set (e.g., subband #0, subband #1, subband #2, and subband #3).

[0274] In addition, Figure 18 As an example, in symbol #4 of time slot #0, terminal 200 detects DL bursts transmitted in subbands #3 and #4. Therefore, in Figure 18 In this context, the period from symbol #0 to symbol #3 in time slot #0 corresponds to stage A, the period from symbol #4 to symbol #13 in time slot #0 corresponds to stage B, and the period after time slot #1 (e.g., the period from symbol #0 to symbol #13 in time slot #1) corresponds to stage C. Additionally, in Figure 18 As mentioned above, phases A and B (e.g., time slot #0) are classified into phase 1, and phase C (e.g., time slot #1) is classified into phase 2.

[0275] In addition, Figure 18 In the example, imagine that during the period after symbol #4 in time slot #0 (e.g., until the end of phase B), no new LBT subbands are added except for subbands #2 and #3.

[0276] In Phase 1, for example, in LBT subbands where DL bursts may be transmitted (e.g., Figure 18 In sub-bands #0 to #3, if PDCCH monitoring opportunities are set, base station 100 allocates PDCCH monitoring opportunities.

[0277] On the other hand, in the second phase, base station 100, for example, transmits LBT subbands that have sent DL bursts (e.g., Figure 18 PDCCH monitoring opportunities are allocated to subbands #2 and #3 in the LBT subband (e.g., LBT subbands that have not sent DL bursts). Figure 18 Subband #0 and subband #1 in the PDCCH are assigned monitoring opportunities.

[0278] Furthermore, even in Phase B of Phase 1 (in other words, when a DL burst has been detected in at least a portion of the subbands), the same PDCCH monitoring opportunity is allocated as in Phase A (in other words, before the DL burst was detected). Here, a DL burst has been transmitted in at least one LBT subband in Phase B. However, sometimes a DL burst is not transmitted in all LBT subbands in Phase B. In this case, even in LBT subbands of Phase B where no DL burst was transmitted, the terminal 200 continues to monitor the PDCCH. For example, in Figure 18During the first phase, whether in phase A or phase B, PDCCH monitoring opportunities are effective in subband #0 and subband #1.

[0279] In this way, even in phase B, the same PDCCH monitoring opportunities as in phase A (in other words, before the detection of the DL burst) will be allocated. By setting these PDCCH monitoring opportunities, for example, if an LBT subband that could not be utilized near the beginning of phase B becomes available from the middle of phase B, the terminal 200 can add more LBT subbands to be used, thus improving resource utilization efficiency.

[0280] In addition, because PDCCH monitoring opportunities are configured in each LBT subband in Phase 1, the terminal 200 can perform DL burst detection regardless of which LBT subband becomes available.

[0281] Furthermore, the number of BDs in the PDCCH monitoring opportunities for each symbol in each sub-band can be set to, for example, 1. By setting this number of BDs, the increase in the number of BDs in the frequency domain can be suppressed, while the number of BDs in the time domain can be increased. Therefore, the granularity of the PDCCH monitoring opportunities in the time domain can be set more finely. For example, in Figure 18 In the first phase, one PDCCH monitoring opportunity is configured for every 2 symbols.

[0282] Alternatively, for example, the same (e.g., identical) payload size can be set between the GC-PDCCH used for detecting DL bursts and the PDCCH used for scheduling PDSCH, etc. By setting this payload size, for example, the terminal 200 can receive both the GC-PDCCH and the PDCCH in one BD.

[0283] In this way, the same PDCCH monitoring opportunity is set in phase A and phase B, which are equivalent to one time slot, thus, for example, it is possible to suppress the complexity of scheduling processing in base station 100 or reception processing in terminal 200.

[0284] Additionally, in phase 2, when LBT subbands that detect DL bursts (e.g., Figure 18 Configure PDCCH monitoring opportunities in subbands #2 and #3 (in the middle) to prevent LBT subbands from detecting DL bursts (e.g., Figure 18 Configure PDCCH monitoring opportunities in sub-bands #0 and #1.

[0285] With this configuration, in Phase 2, for example, PDCCH monitoring opportunities will not be allocated in other LBT subbands that are different from the LBT subbands that sent DL bursts, thus reducing the number of BDs or CCEs.

[0286] Additionally, in Phase 2, the PDCCH monitoring opportunities can be configured differently from those in Phase 1. For example, it can be configured as follows: Figure 18 As shown, in Phase 2, one PDCCH monitoring opportunity in the time domain will be configured in each time slot. For example, it could be, as... Figure 18 As shown, in Phase 1, PDCCH monitoring opportunities are distributed across the time domain, while in Phase 2, PDCCH monitoring opportunities are centrally distributed across the time domain. Additionally, for example, in... Figure 18 In the example shown, the PDCCH monitoring opportunities set in the second stage in each subband are configured over a larger range in the frequency domain compared to the PDCCH monitoring opportunities set in the first stage.

[0287] In addition, such as Figure 18 As shown, for example, during Phase 1, PDCCH monitoring opportunities set for Phase 1 will continue to be allocated regardless of whether a DL burst is detected (in other words, regardless of the phase). In other words, PDCCH monitoring opportunities are not switched during Phase 1. For example, as... Figure 18 As shown, PDCCH monitoring opportunities can be switched between Phase 1 and Phase 2 (in other words, between time slots). This switching reduces the number of times PDCCH monitoring opportunities need to be switched.

[0288] Thus, in this embodiment, the base station 100 and the terminal 200 determine, for example, the PDCCH monitoring opportunities (in other words, the PDCCH configuration method) within at least one of the following two based on information related to at least one of the maximum BD number and the maximum CCE number: phase A (the period before the time when the DL burst is detected), and phases B and C (the period after the time when the DL burst is detected).

[0289] For example, in this embodiment, the same PDCCH monitoring opportunity allocation is set for both Phase A and Phase B in Phase 1 (in other words, the PDCCH configuration method). Alternatively, a different PDCCH monitoring opportunity allocation is set for Phase 1 (e.g., Phase A and Phase B) than for Phase 2 (e.g., Phase C). Furthermore, for example, the presence or absence of PDCCH monitoring opportunities in LBT subbands that do not send DL bursts switches between Phase 1 and Phase 2.

[0290] By setting the PDCCH monitoring opportunities as described above, the PDCCH monitoring opportunities are switched on a time resource basis (e.g., on a time slot basis). In other words, the PDCCH monitoring opportunities are not switched in the middle of a time slot, thus, for example, the complexity of scheduling processing in base station 100 or reception processing in terminal 200 can be suppressed. In addition, according to this embodiment, for example, PDCCH monitoring opportunities corresponding to each stage in DL burst detection can be allocated.

[0291] also, Figure 18 The configuration of PDCCH monitoring opportunities shown in each stage is an example and is not limited to... Figure 18 The example shown. For instance, the number of BDs for each symbol configured with PDCCH monitoring opportunities in Phase 1 is not limited to one, but can be multiple. Additionally, for instance, at least one of the symbol positions and the number of symbols configured with PDCCH monitoring opportunities in Phase 1 and Phase 2 is not limited to... Figure 18 The example shown could also be in other positions or with other numbers.

[0292] (Implementation Method 3)

[0293] To switch PDCCH monitoring opportunities, configuration information for a number of CORESETs and SSs, equivalent to the number of PDCCH monitoring opportunity allocation modes, can be prepared. Then, the PDCCH monitoring opportunity can be switched by changing the configuration information of the CORESETs and SSs. However, as mentioned above, the number of CORESETs and SSs that can be configured is limited. Therefore, there is still room for research into methods for switching PDCCH monitoring opportunities while preventing an increase in the number of CORESETs and SSs.

[0294] [Structure of base stations and terminals]

[0295] The structures of the base station and terminal in this embodiment are interchangeable with those of the base station 100 and terminal 200 in Embodiment 1.

[0296] In this embodiment, the scheduling unit 104 of the base station 100 switches the application dropping rules according to the current stage. The scheduling unit 104 may, for example, determine the dropping of SS based on the switched dropping rules.

[0297] In this embodiment, the receiving control unit 205 of the terminal 200, like the scheduling unit 104, switches the application's discarding rules according to the current stage. For example, the receiving control unit 205 performs SS discarding determination based on the switched discarding rules.

[0298] [PDCCH Monitoring Opportunity Decision-Making Method]

[0299] This describes an example of the method for determining PDCCH monitoring opportunities in the scheduling unit 104 of base station 100. Additionally, the reception control unit 205 of terminal 200 can determine PDCCH monitoring opportunities based on the same determination method as the scheduling unit 104.

[0300] In this embodiment, the base station 100 may, for example, switch the applied drop rule (in other words, a rule that does not set PDCCH monitoring opportunities) according to the stage in DL burst detection (e.g., stage A, stage B, or stage C). For example, different drop rules may be applied to each stage. By applying this drop rule, PDCCH monitoring opportunities can be set according to the stage.

[0301] Figure 19 This describes a setting example of the PDCCH monitoring opportunity in this embodiment.

[0302] Figure 19 (a) represents an example of the state when setting up a PDCCH monitoring opportunity. Figure 19 In (a), in each LBT subband, one PDCCH monitoring opportunity (e.g., SS or BD) is set for every 2 symbols (e.g., even-numbered symbols). In addition, the number of PDCCH candidates for each symbol in each LBT subband is 11 (in other words, the number of BDs is 11).

[0303] Figure 19 (b) represents a setting example of the PDCCH monitoring opportunity in stage A.

[0304] In progress Figure 19 In setting (a), 11 PDCCH candidates (in other words, 11 BDs) are set in each symbol of each LBT subband during the PDCCH monitoring opportunity, while... Figure 19 In (b), one PDCCH candidate is set (in other words, 1BD). In other words, in Figure 19 In (b), 10 out of 11 PDCCH candidates were discarded, and 1 PDCCH candidate was set.

[0305] For example, one of the following methods (1) to (3) can be used as... Figure 19 The discard rule of (b).

[0306] (1) Discard all PDCCH candidates and PDCCH monitoring opportunities except for one PDCCH candidate in a certain AL. Regarding the selection method of the one PDCCH candidate, for example, the PDCCH candidate at the front end can be selected, the PDCCH candidate can be randomly selected, the PDCCH candidate can be specified by signaling, or other methods can be used to select the PDCCH candidate.

[0307] (2) If the AL and the number of PDCCH candidates within the AL are given priority based on the PDCCH candidates, and the number of BD or CCE set for the terminal 200 exceeds the threshold (e.g., the maximum number of BD or the maximum number of CCE), the PDCCH candidates and PDCCH monitoring opportunities are discarded.

[0308] For example, given AL1, 2, and 4, the following rule is envisioned: higher priority is assigned in the order of AL2, 4, 1, and within the same AL, higher priority is assigned in ascending order of PDCCH candidate number. Furthermore, the PDCCH candidate number could, for example, be equivalent to ms,nCI in Section 10.1 of Non-Patent Document 3. Figure 19 In the example shown in (b), when the maximum value of CCE is 56CCE, 4 subbands × 7 symbols × 2CCE = 56CCE. Therefore, in each even symbol of each LBT subband, one AL 2 PDCCH candidate is configured for each PDCCH monitoring opportunity, and AL PDCCH candidates and PDCCH monitoring opportunities that are different from AL 2 are discarded.

[0309] (3) Discard PDCCH candidates and PDCCH monitoring opportunities based on SS ID. Figure 19 In the example shown in (b), if we assume that 11BD is divided into SS ID#1 (BD number = 1) and SS ID#2 (BD number = 10), then when SS ID-based discarding is performed in stage A, the PDCCH candidate of SS ID#1 is configured in the PDCCH monitoring opportunity of each even digital element in each LBT subband, while the PDCCH candidate of SS ID#2 and the PDCCH monitoring opportunity are discarded.

[0310] Figure 19 (c) represents the setting example of the PDCCH monitoring opportunity in stage C.

[0311] exist Figure 19 In (c), for example, in each LBT subband, PDCCH candidates and PDCCH monitoring opportunities of symbols #2 to #12 are discarded, and PDCCH candidates and PDCCH monitoring opportunities of symbol #0 are set.

[0312] For example, one of the following methods (4) or (5) can be used as... Figure 19 The discard rule in (c).

[0313] (4) If PDCCH candidates and PDCCH monitoring opportunities are configured sequentially starting from the front-end symbols within the time slot, and the number of BDs or CCEs set for terminal 200 exceeds a threshold (e.g., maximum number of BDs or maximum number of CCEs), the remaining PDCCH candidates and PDCCH monitoring opportunities are discarded. Figure 19 In the example shown in (c), if PDCCH candidates and PDCCH watch opportunities are configured in symbol #0, the BD count will reach the maximum BD count (44 times). Therefore, PDCCH candidates and PDCCH watch opportunities of other symbols different from symbol #0 are discarded.

[0314] (5) Discard PDCCH candidates and PDCCH monitoring opportunities based on SS ID. Figure 19 In the example shown in (c), if we assume that SS ID #1 (BD number 11) is set in symbol #0 and SS ID #2 (BD number 11) is set in other symbols different from symbol #0, then when discarding based on SS ID is performed in stage C, the PDCCH candidate and PDCCH monitoring opportunity of symbol #0 are configured, and the PDCCH candidate and PDCCH monitoring opportunity of other symbols different from symbol #0 are discarded.

[0315] Thus, according to this embodiment, by applying different discard rules at each stage, different PDCCH configurations can be set at each stage.

[0316] In addition, Figure 19 The example shown illustrates the discarding rules for stages A and C, but it is not limited to these; different discarding rules can be applied to any stage. Alternatively, for example, different discarding rules can be applied to each of the "PDCCH monitoring stages" defined in Implementation 2.

[0317] In addition, the association between the stage and the discard rule can be communicated to the terminal 200 by the base station 100 via signaling information, or it can be specified in the specification (or standard).

[0318] Thus, base station 100 and terminal 200 determine, for example, the PDCCH monitoring opportunities (in other words, the PDCCH configuration method) within at least one of the following two periods based on information related to at least one of the maximum BD number and the maximum CCE number: phase A (the period before the time when the DL burst is detected), and phases B and C (the period after the time when the DL burst is detected).

[0319] For example, in this embodiment, the base station 100 and the terminal 200 set drop rules (in other words, rules that determine which PDCCH resources are not configured) for each phase in DL burst detection or for each PDCCH monitoring stage (in other words, time slot). In other words, different drop rules are set according to the phase or stage. Through this setting, the base station 100 and the terminal 200 can configure the PDCCH corresponding to each phase or stage. Furthermore, for example, with the same CORESET and SS settings, the PDCCH configuration can be changed by changing the drop rules. Therefore, compared to methods that change the PDCCH configuration by setting different CORESETs and SSs, this embodiment can reduce the number of CORESET / SS settings.

[0320] The above describes one embodiment of the present invention.

[0321] (Other implementation methods)

[0322] In the above embodiments, the phrase "discard PDCCH candidates and PDCCH monitoring opportunities" can be replaced with "do not configure (map) PDCCH candidates and PDCCH monitoring opportunities." Similarly, the phrase "do not discard PDCCH candidates and PDCCH monitoring opportunities" can be replaced with "configure (map) PDCCH candidates and PDCCH monitoring opportunities." Furthermore, even when it is stated as "discard PDCCH candidates and PDCCH monitoring opportunities," for example, when multiple PDCCH candidates are set in the same PDCCH monitoring opportunity (time resource, frequency resource), it is sometimes possible not to discard the PDCCH monitoring opportunity.

[0323] Furthermore, in the above embodiments, the downlink control channel for transmitting control signals is not limited to PDCCH, but can also be a control channel with other names.

[0324] In the above embodiments, the unit of time resources (or unit time interval) is not limited to time slots or symbols, but can also be other time resource units (e.g., subframes, frames, or micro-slots). Similarly, the unit of frequency resources is not limited to subbands, but can also be other frequency resource units (e.g., resource blocks (PRBs), RB groups (RBGs), BWPs, subcarriers, or resource element groups (REGs)).

[0325] Alternatively, the above-described implementation methods can be combined and applied separately.

[0326] This invention can be implemented in software, hardware, or software in cooperation with hardware. The functional blocks used in the above embodiments are implemented partially or wholly as LSIs (Large Scale Integration), and the processes described in the above embodiments can also be controlled partially or wholly by a single LSI or a combination of LSIs. An LSI can be composed of individual chips, or it can be composed of a single chip containing some or all of the functional blocks. An LSI may also include data input and output. Depending on the degree of integration, an LSI may also be called an "IC (Integrated Circuit)," a "System LSI," a "Super LSI," or an "Ultra LSI."

[0327] The method of integrating LSIs is not limited to LSIs; it can also be implemented using dedicated circuits, general-purpose processors, or special-purpose processors. Alternatively, LSIs can be used to fabricate programmable FPGAs (Field Programmable Gate Arrays), or reconfigurable processors that allow for reconfiguration of the connections or settings of the internal circuit blocks of an LSI. This invention can also be implemented for digital or analog processing.

[0328] Furthermore, if advancements in semiconductor technology or the emergence of other derivative technologies lead to integrated circuit technologies that can replace LSIs, these technologies could also be used to integrate functional blocks. There are also possibilities for applications such as biotechnology.

[0329] This invention can be implemented in all kinds of devices, apparatuses, and systems with communication capabilities (collectively referred to as "communication devices"). A communication device may also include a wireless transceiver and processing / control circuitry. The wireless transceiver may also include a receiving unit and a transmitting unit, or perform the functions of these units. The wireless transceiver (transmitting unit, receiving unit) may also include an RF (Radio Frequency) module and one or more antennas. The RF module may also include an amplifier, an RF modulator / demodulator, or similar devices. Non-limiting examples of communication devices include: telephones (mobile phones, smartphones, etc.), tablet computers, personal computers (PCs) (laptops, desktops, laptops, etc.), cameras (digital cameras, digital camcorders, etc.), digital players (digital audio / video players, etc.), wearable devices (wearable cameras, smartwatches, tracking devices, etc.), game consoles, e-book readers, remote health / telemedicine (remote healthcare / medical prescription) devices, vehicles or transportation vehicles with communication capabilities (cars, airplanes, ships, etc.), and combinations of the various devices described above.

[0330] Communication devices are not limited to portable or movable devices, but also include all kinds of devices, equipment, and systems that cannot be carried or fixed. Examples include: smart home devices (home appliances, lighting equipment, smart meters or meters, control panels, etc.), vending machines, and all other "things" that can exist on the IoT (Internet of Things) network.

[0331] In addition to data communication via cellular systems, wireless LAN (Local Area Network) systems, and communication satellite systems, communication also includes data communication via a combination of these systems.

[0332] In addition, the communication device also includes devices such as controllers or sensors that are connected or linked to the communication equipment performing the communication functions described in this invention. For example, it includes controllers or sensors that generate control signals or data signals used by the communication equipment performing the communication functions of the communication device.

[0333] In addition, the communication device includes infrastructure equipment that communicates with or controls the various devices described above (not limited to these), such as base stations, access points, and all other devices, equipment, and systems.

[0334] A base station according to an embodiment of the present invention includes: a control circuit that determines a configuration method for the downlink control channel signal during at least one of a first period before a carrier-based sensing opportunity and a second period after the carrier-based sensing opportunity, based on information relating to at least one of the number of blind decodings of the downlink control channel signal and the number of resources estimated for the channel; and a transmission circuit that transmits the downlink control channel signal based on the determined configuration method.

[0335] In one embodiment of the present invention, the configuration method is based on the priority of multiple frequency resources.

[0336] In one embodiment of the invention, the configuration method is based on the priority of the plurality of frequency resources in the first period and on the priority of at least one frequency resource based on carrier sensing in the second period.

[0337] In one embodiment of the present invention, in the configuration method, if at least one of the number of blind decoding attempts and the number of resources exceeds a threshold, the downlink control channel signal is not configured based on the priority.

[0338] In one embodiment of the present invention, the same configuration method is set during the periods in the first period and the second period that are within the same unit time interval as the first period.

[0339] In one embodiment of the present invention, during a period in the second period that is in a different unit time interval than the first period, a configuration method different from the configuration method in the first period is set.

[0340] In one embodiment of the present invention, the control circuit sets a configuration method for the first period and the second period respectively, or sets a configuration method for each unit time interval including the following rule, which is a rule for determining not to configure the resources of the downlink control channel signal.

[0341] A terminal according to one embodiment of the present invention includes: a control circuit that determines, based on information relating to at least one of the number of blind decodings of the downlink control channel signal and the number of resources estimated for the channel, a reception opportunity for the downlink control channel signal during at least one of a first period before the detection opportunity and a second period after the detection opportunity; and a receiving circuit that receives the downlink control channel signal at the determined reception opportunity.

[0342] In a transmission method according to an embodiment of the present invention, a base station performs the following steps: determining a configuration method for the downlink control channel signal during at least one of a first period before a carrier-based sensing opportunity and a second period after the carrier-based sensing opportunity, based on information relating to at least one of the number of blind decodings of the downlink control channel signal and the number of resources estimated for the channel; and transmitting the downlink control channel signal based on the determined configuration method.

[0343] In a receiving method according to an embodiment of the present invention, the terminal performs the following steps: determining, based on information relating to at least one of the number of blind decodings of the downlink control channel signal and the number of resources estimated for the channel, the receiving opportunity of the downlink control channel signal during at least one of a first period before the detection opportunity and a second period after the detection opportunity; and receiving the downlink control channel signal at the determined receiving opportunity.

[0344] The entire contents of the description, drawings and abstract of the description contained in Japanese Patent Application No. 2019-184566, filed on October 7, 2019, are incorporated herein by reference.

[0345] Industrial applicability

[0346] One embodiment of the present invention is useful for wireless communication systems.

[0347] Explanation of reference numerals in the attached figures

[0348] 100 base stations

[0349] Receiving Departments 101 and 201

[0350] 102, 202 Demodulation / Decoding Unit

[0351] 103 Channel State Estimation Unit

[0352] 104 Dispatch Department

[0353] 105, 204 Control Information Retention Section

[0354] 106 Data / Control Information Generation Unit

[0355] 107, 208 Encoding / Modulation Unit

[0356] 108, 209 Sending Department

[0357] 200 terminals

[0358] 203 DL Sending Inspection Department

[0359] 205 Receiving Control Unit

[0360] 206 Transmission Control Department

[0361] 207 Data Generation Department.

Claims

1. A base station, characterized by comprising: comprising: control circuitry that determines a first search space and a second search space for a downlink control channel, the second search space being different from the first search space; and a transmitter that transmits the downlink control channel, the downlink control channel being transmitted in the first search space in a first period and in the second search space in a second period, upon switching from the first search space to the second search space, after detecting a downlink burst in a symbol of the first search space, using the first search space until a slot boundary and, from the slot boundary, using the second search space.

2. The base station according to claim 1, wherein only one of the first search space and the second search space is used in one slot.

3. The base station according to claim 1, wherein the first period includes a period before detecting a signal transmitted by the base station and a period from detecting the signal to a slot boundary, the second period is a period after the slot boundary.

4. The base station according to claim 1, wherein a frequency domain configured in the second search space is larger than a frequency domain configured in the first search space.

5. A communication method characterized by comprising: comprising the steps of: determining a first search space and a second search space for a downlink control channel, the second search space being different from the first search space; and transmitting the downlink control channel, the downlink control channel being transmitted in the first search space in a first period and in the second search space in a second period, upon switching from the first search space to the second search space, after detecting a downlink burst in a symbol of the first search space, using the first search space until a slot boundary and, from the slot boundary, using the second search space.

6. The communication method according to claim 5, wherein only one of the first search space and the second search space is used in one slot.

7. The communication method according to claim 5, wherein the first period includes a period before detecting a signal transmitted by a base station and a period from detecting the signal to a slot boundary, the second period is a period after the slot boundary.

8. The communication method according to claim 5, wherein a frequency domain configured in the second search space is larger than a frequency domain configured in the first search space.

9. A communications device, characterized by comprising: control circuitry that determines a first search space and a second search space for a downlink control channel, the second search space being different from the first search space; and a receiver that receives the downlink control channel, the downlink control channel being received in the first search space in a first period and in the second search space in a second period, upon switching from the first search space to the second search space, after detecting a downlink burst in a symbol of the first search space, using the first search space until a slot boundary and, from the slot boundary, using the second search space. after detecting a downlink burst in a symbol of the first search space, using the first search space until a slot boundary, and using the second search space from the slot boundary.

10. The communication apparatus according to claim 9, wherein, only one of the first search space and the second search space is used in one slot.

11. The communication apparatus according to claim 9, wherein, the first period includes a period before detecting a signal transmitted by a base station, and a period from detecting the signal to a slot boundary, the second period is a period after the slot boundary.

12. The communication apparatus according to claim 9, wherein, a frequency domain configured in the second search space is larger than a frequency domain configured in the first search space.

13. A method of communication, comprising: comprising: determining a first search space and a second search space for a downlink control channel, the second search space being different from the first search space; and receiving the downlink control channel, the downlink control channel is received in the first search space in a first period, and the downlink control channel is received in the second search space in a second period, after detecting a downlink burst in a symbol of the first search space, using the first search space until a slot boundary, and using the second search space from the slot boundary.

14. The communication method according to claim 13, wherein, only one of the first search space and the second search space is used in one slot.

15. The communication method according to claim 13, wherein, the first period includes a period before detecting a signal transmitted by a base station, and a period from detecting the signal to a slot boundary, the second period is a period after the slot boundary.

16. The communication method according to claim 13, wherein, a frequency domain configured in the second search space is larger than a frequency domain configured in the first search space.

17. An integrated circuit, comprising: comprising: determining a first search space and a second search space for a downlink control channel, the second search space being different from the first search space; and transmitting the downlink control channel, the downlink control channel is transmitted in the first search space in a first period, and the downlink control channel is transmitted in the second search space in a second period, after detecting a downlink burst in a symbol of the first search space, using the first search space until a slot boundary, and using the second search space from the slot boundary.

18. An integrated circuit, comprising: comprising: determining a first search space and a second search space for a downlink control channel, the second search space being different from the first search space; and receiving the downlink control channel, the downlink control channel is received in the first search space in a first period, and the downlink control channel is received in the second search space in a second period, the downlink control channel is received in the first search space in a first period, the downlink control channel is received in the second search space in a second period, upon switching from the first search space to the second search space, using the first search space after detecting a downlink burst in a symbol of the first search space until a slot boundary, and using the second search space from the slot boundary.

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