Communication system

Abstract

An integrated circuit according to the present application for controlling a terminal, the integrated circuit comprising: a control circuit that receives, from a base station, polarization wave information for uplink transmission and / or downlink transmission of wireless communication, the polarization wave information including at least one of left-hand circular polarization wave information (LHCP information), right-hand circular polarization wave information (RHCP information), and linear polarization wave information; and a communication circuit that performs the wireless communication using a polarization wave indicated in the received polarization wave information, wherein the reception circuit receives the polarization wave information including polarization wave information of a surrounding cell, and the communication circuit performs radio measurement on the surrounding cell using the polarization wave indicated in the received polarization wave information of the surrounding cell.

Description

[0001] This application is a divisional application of Chinese invention patent application filed on September 28, 2020, with application number 202080074773.8, entitled "Terminal and Communication Method", and filed by Panasonic (USA) Intellectual Property Company. Technical Field

[0002] This disclosure relates to terminals and communication methods. Background Technology

[0003] Regarding 5G standardization, the 3rd Generation Partnership Project (3GPP) has discussed New Radio access technology (NR) and released the NR Release (Rel.) 15 specification.

[0004] Existing technical documents

[0005] Non-patent literature

[0006] Non-patent document 1: 3GPP, TR38.811 V15.2.0, “Study on New Radio (NR) to support non terrestrial networks (Release 15),” 2019-09

[0007] Non-patent literature 2: 3GPP TSG RAN WG1 #98bis, R1-1911003, “On physical layer control procedures for NTN,” October, 2019 Summary of the Invention

[0008] However, there is still room for research regarding the methods for determining the polarization waves used in wireless communication systems.

[0009] The non-limiting embodiments disclosed herein help to provide terminals and communication methods capable of appropriately determining the polarization waves used for wireless communication.

[0010] One aspect of this disclosure is an integrated circuit for controlling a terminal, the integrated circuit comprising: a receiving circuit for receiving from a base station polarization wave information for uplink and / or downlink transmission for wireless communication, the polarization wave information including at least one of left-hand circularly polarized wave information (LHCP information), right-hand circularly polarized wave information (RHCP information), and linearly polarized wave information; and a communication circuit for performing the wireless communication using the polarization wave indicated in the received polarization wave information, wherein the receiving circuit receives the polarization wave information including polarization wave information of surrounding cells, and the communication circuit uses the polarization wave indicated in the received polarization wave information of the surrounding cells to perform radio measurements of the surrounding cells.

[0011] One aspect of this disclosure is an integrated circuit for controlling a base station. The integrated circuit includes: a transmitting circuit that transmits uplink and / or downlink polarization information for wireless communication with a terminal, the polarization information including at least one of left-hand circularly polarized wave information (LHCP), right-hand circularly polarized wave information (RHCP), and linearly polarized wave information; and a communication circuit that performs the wireless communication using the polarization wave indicated in the transmitted polarization information, wherein the transmitting circuit transmits the polarization information including polarization information of surrounding cells.

[0012] A terminal according to one embodiment of this disclosure includes: a control circuit that determines a polarization wave to be used in at least one of a first wireless communication and a second wireless communication, the second wireless communication being a wireless communication following the first wireless communication; and a communication circuit that performs the wireless communication of the at least one using the determined polarization wave.

[0013] 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.

[0014] According to one embodiment of this disclosure, the polarization wave used for wireless communication can be appropriately determined.

[0015] Further advantages and effects of one embodiment of this disclosure will be illustrated by the specification and accompanying drawings. These advantages and / or effects are provided by the various embodiments and the features described in the specification and drawings, but it is not necessarily necessary for all of these features to be provided in order to obtain one or more of the same features. Attached Figure Description

[0016] Figure 1 This is a diagram illustrating the exemplary architecture of a 3GPP NR system.

[0017] Figure 2This is a schematic diagram illustrating the functional separation between NG-RAN (Next Generation-Radio Access Network) and 5GC (5th Generation Core).

[0018] Figure 3 This is a sequence diagram of the setting / resetting process for an RRC (Radio Resource Control) connection.

[0019] Figure 4 This is a schematic diagram illustrating the application scenarios of high-capacity high-speed communication (eMBB), massive machine-type communications (mMTC), and ultra-reliable and low-latency communications (URLLC).

[0020] Figure 5 This is a block diagram representing an exemplary 5G system architecture for non-roaming scenarios.

[0021] Figure 6 This is a diagram illustrating an example of a method for reusing resources.

[0022] Figure 7 This is a block diagram showing the structure of a portion of the base station in Implementation Method 1.

[0023] Figure 8 This is a block diagram showing the structure of a portion of the terminal in Embodiment 1.

[0024] Figure 9 This is a block diagram illustrating an example of the structure of a base station according to Implementation Method 1.

[0025] Figure 10 This is a block diagram illustrating an example of the structure of the terminal in Implementation Method 1.

[0026] Figure 11 This is a diagram representing an example of initial access.

[0027] Figure 12 This is a flowchart illustrating an example of the operation of the terminal in method 1 of implementation method 1.

[0028] Figure 13 This is a flowchart illustrating an example of the operation of the terminal in method 2 of implementation method 1.

[0029] Figure 14This is a flowchart illustrating an example of the operation of the terminal in method 3 of implementation method 1.

[0030] Figure 15 This is a diagram representing an example of a quasi-co-location (QCL) type.

[0031] Figure 16 This is a diagram illustrating an example of a Radio Resource Control (RRC) message associated with the TCI (Transmission Configuration Indication) state and QCL.

[0032] Figure 17 This is a diagram representing an example of precoding information.

[0033] Figure 18 This is a flowchart illustrating an example of the operation of the terminal in Implementation Method 2.

[0034] Figure 19 This is a flowchart illustrating an example of the operation of the terminal in Implementation Method 3. Detailed Implementation

[0035] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0036] <5G NR System Architecture and Protocol Stack>

[0037] 3GPP is continuing its work to develop the next generation of mobile phone technology (also known simply as "5G"), which includes a new radio access technology (NR) operating in the frequency range up to 100 GHz. The first version of the 5G standard was completed at the end of 2017, which allowed for the trial production and commercialization of terminals (e.g., smartphones) that could transition to the 5G NR standard.

[0038] 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 38.300 v15.6.0, section 4).

[0039] 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.

[0040] For example, the media access control layer handles the multiplexing of logical channels, the scheduling of processing involving various parameter sets (numerology), and the various functions associated with the scheduling.

[0041] 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); downlink physical channels include PDSCH (Physical Downlink Shared Channel), PDCCH (Physical Downlink Control Channel), and PBCH (Physical Broadcast Channel).

[0042] In NR use cases / extended scenarios, enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine-type communications (mMTC) may have multiple necessary conditions 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, more stringent necessary conditions are imposed for ultra-low latency (0.5ms latency in both UL and DL) and high reliability (within 1ms, 1-10-5). Finally, in mMTC, high connection density (1,000,000 devices / km in urban environments) is preferably required. 2 ), wide coverage in harsh environments, and extremely long-lasting batteries (15 years) for inexpensive devices.

[0043] Therefore, a set of OFDM (Orthogonal Frequency Division Multiplexing) parameters suitable for one use case (e.g., subcarrier spacing, OFDM symbol length, cyclic prefix (CP) length, number of symbols per scheduling interval) may be invalid in other use cases. For example, in low-latency services, it is preferable to have 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 have 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. The symbol length Tu and the subcarrier spacing Δf are directly related according to the formula Δf = 1 / Tu. Similar to LTE (Long Term Evolution) systems, 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.

[0044] 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).

[0045] <Functional Separation between NG-RAN and 5GC in 5G NR>

[0046] 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).

[0047] For example, gNB and ng-eNB perform the following main functions:

[0048] - 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;

[0049] - Data IP (Internet Protocol) header compression, encryption, and integrity protection;

[0050] - 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;

[0051] - Routing to user plane data towards UPF;

[0052] - Routing of control plane information toward AMF;

[0053] - Setting and canceling connections;

[0054] - Scheduling and sending paging messages;

[0055] - The scheduling and transmission of system broadcast information (originating from AMF or Operation, Admission, and Maintenance functions (OAM));

[0056] - Setting up measurements and measurement reports for mobility and scheduling;

[0057] - Packet markings for transmission class in the uplink;

[0058] -Session management;

[0059] -Support for network slicing;

[0060] - QoS (Quality of Service) flow management and mapping to data radio bearers;

[0061] Support for UEs in RRC_INACTIVE (RRC inactive) state;

[0062] - NAS (Non-Access Stratum) message distribution function;

[0063] - Sharing of wireless access networks;

[0064] - Dual connectivity;

[0065] - Close collaboration between NR and E-UTRA (Evolved Universal Terrestrial Radio Access).

[0066] The Access and Mobility Management (AMF) function performs the following main functions:

[0067] - Function to terminate Non-Access Stratum (NAS) signaling;

[0068] -Security of NAS signaling;

[0069] - Security controls at the access layer (AS);

[0070] - Core Network (CN) inter-node signaling for mobility between 3GPP access networks;

[0071] - The possibility of a UE reaching idle mode (including control and execution of paging retransmission);

[0072] - Management of the registered area;

[0073] - Support for intra-system mobility and inter-system mobility;

[0074] -Access authentication;

[0075] - Access licenses that include roaming permission checks;

[0076] - Mobility management controls (subscription and policies);

[0077] -Support for network slicing;

[0078] - Selection of Session Management Function (SMF).

[0079] In addition, the User Face Function (UPF) performs the following main functions:

[0080] - Anchor points for intra-RAT (Radio Access Technology) mobility / inter-RAT (where applicable) mobility;

[0081] - External PDU (Protocol Data Unit) session points used for interconnection with data networks;

[0082] - Packet routing and forwarding;

[0083] - Enforcement of policy rules in group checks and user-facing aspects;

[0084] - Reports on business usage;

[0085] - Uplink classifier used to support routing of service flows toward the data network;

[0086] - Branching points used to support multi-homed PDU sessions;

[0087] - For user plane QoS processing (e.g., packet filtering, gating, UL / DL rate enforcement);

[0088] - Uplink service verification (SDF (Service Data Flow) mapping to QoS flow);

[0089] - Downlink packet buffering and downlink data notification triggering functions.

[0090] Finally, the Session Management Function (SMF) performs the following main functions:

[0091] -Session management;

[0092] - The allocation and management of UE IP addresses;

[0093] -Selection and control of UPF;

[0094] - A function for setting traffic steering in the User Plane Function (UPF) to direct traffic to the appropriate destination;

[0095] - Enforcing policies and QoS in the control section;

[0096] - Notification of downlink data.

[0097] <The process of setting up and resetting RRC connection>

[0098] Figure 3 This describes some interactions between the UE, gNB, and AMF (5GC entity) in the NAS part when the UE transitions from RRC_IDLE (RRC idle) to RRC_CONNECTED (RRC connected) (refer to TS 38.300 v15.6.0).

[0099] 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 connections consisting solely of signaling, 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.

[0100] Therefore, this disclosure provides an entity (e.g., AMF, SMF, etc.) for a fifth-generation core network (5GC), comprising: a control circuit that, upon operation, establishes a Next Generation (NG) connection with a gNode (node) B; and a transmission unit that, upon operation, sends an initial context setting message to the gNode B via the NG connection to configure the signaling radio bearer between the gNode B and the User Equipment (UE). Specifically, the gNode B transmits Radio Resource Control (RRC) signaling containing a Resource Allocation Setting 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.

[0101] <Application Scenarios of IMT after 2020>

[0102] 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 ).

[0103] 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.

[0104] 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 critical applications.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] Regarding NR URLLC, further use cases with more stringent requirements are envisioned, such as factory automation, transportation, and power transmission. Stricter requirements refer to high reliability (reaching level 10⁻⁶), high availability, a packet size of 256 bytes, and time synchronization of approximately several microseconds (μs) (capable of corresponding to use cases, with values ​​set to 1 μs or several microseconds depending on the frequency range and short latency of approximately 0.5ms to 1ms (e.g., 0.5ms latency in the target user plane)).

[0109] 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 (Channel State Information) feedback. Furthermore, there may be enhancements to PUSCH associated with micro-slot-level frequency hopping and retransmission / repetition. The term "micro-slot" refers to a transmission time interval (TTI) containing fewer symbols than a time slot (a time slot has 14 symbols).

[0110] <QoS Control>

[0111] 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 NG-U interface with an encapsulation header.

[0112] 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.

[0113] Figure 5 This refers to the non-roaming reference architecture of 5G NR (refer to TS 23.501 v16.1.0, section 4.23). Application Function (AF) (e.g., undertaking...) 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.

[0114] 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.

[0115] Therefore, this disclosure 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 gNodeB and a UE corresponding to QoS requirements, sends, during operation, a request containing at least one of the QoS requirements for URLLC service, eMMB service, and mMTC service to at least one of the functions of 5GC (e.g., NEF, AMF, SMF, PCF, UPF, etc.); and a control circuit that, during operation, performs services using the established PDU session.

[0116] [Expansion to networks beyond the terrestrial plane (NTN: Non-Terrestrial Network)]

[0117] Rel. 15 is a specification, for example, related to wireless access technologies used in terrestrial networks. On the other hand, NR has studied the extension of communications using satellites or high-altitude pseudo-satellites (HAPS) to networks outside the ground (NTN: Non-Terrestrial Network) (e.g., Non-Patent Document 1).

[0118] In an NTN environment, the satellite coverage area (e.g., more than one cell) for a ground terminal or aircraft terminal is formed, for example, by beams transmitted from the satellite. Alternatively, multiple cells segmenting the coverage area are formed, for example, by transmitting multiple strictly directional beams from the satellite's antenna. The terminal communicates, for example, while moving, by switching cells through handover, similar to terrestrial cellular communication.

[0119] Alternatively, multiple beams from satellites can be bundled together to form a cell. In this case, beam switching mechanisms, such as NR-based beam management, have been studied in NTN environments (e.g., see Non-Patent Literature 2).

[0120] Additionally, frequency reuse can be achieved, for example, by using different frequencies (or channels) between adjacent (or surrounding) beams or cells. In frequency reuse, because different frequencies are used, for example, between adjacent beams or cells, inter-beam interference (in other words, inter-cell interference) can be reduced. For example, as... Figure 6 As shown, in an instance using three frequencies (e.g., F1, F2, and F3), frequency reuse of 3 (or, reuse of 3) can be achieved.

[0121] Furthermore, circular polarization is used, for example, in satellite communications. For instance, between adjacent beams, in addition to frequency reuse, different polarizations can be used to mitigate inter-beam interference. For example, as... Figure 6 As shown, in instances using two frequencies (e.g., F1 and F2) and two polarizations (e.g., right-handed circular polarization (RHCP) and left-handed circular polarization (LHCP)), reuse of 4 is possible.

[0122] The method of reusing polarized waves (e.g., how to utilize the polarized waves, or which polarized waves to utilize) depends, for example, on the network operation. Here, for example, on the receiving side (e.g., a terminal or base station), if the polarized wave to be utilized is known, even a linear polarization antenna can separate the polarization wave and receive the signal. On the other hand, on the receiving side (e.g., a terminal or base station), even if the polarization wave to be utilized is unknown, the signal can be received, for example, through diversity synthesis, thereby receiving signals from two polarization waves (e.g., RHCP and LHCP), but this will result in a loss.

[0123] Thus, for example, if the terminal can determine the polarization wave used by the downlink signal, it can perform reception processing based on the reception method corresponding to the polarization wave, thereby improving reception performance.

[0124] Furthermore, since right-hand circularly polarized waves are orthogonal to left-hand circularly polarized waves, signals can be multiplexed using different circularly polarized waves (e.g., also known as "polarization wave multiplexing transmission"), thereby increasing throughput. In other words, circularly polarized waves can be used not only for resource reuse but also for polarization wave multiplexing transmission.

[0125] However, in 5G NR (e.g., Rel. 15), the methods for terminals to decide which polarization wave to use (e.g., notification method) or the method for using circularly polarized waves have not been sufficiently studied.

[0126] Therefore, this disclosure describes a method for determining the polarization wave at the terminal and a method for utilizing the polarization wave.

[0127] (Implementation Method 1)

[0128] [Overview of Wireless Communication Systems]

[0129] One embodiment of the wireless communication system disclosed herein includes a base station 100 and a terminal 200. The wireless communication system may be, for example, a satellite communication system in an NTN environment, or other wireless communication systems. Both the base station 100 and the terminal 200 are examples of wireless communication devices.

[0130] Figure 7 This is a block diagram illustrating a structural example of a base station 100 according to an embodiment of the present disclosure. Figure 7 In the base station 100 shown, the control unit 11 (e.g., equivalent to a control circuit) determines the polarization wave of the wireless signal for the terminal 200 in at least one of the first phase and the second phase following the first phase of wireless communication. The communication unit 12 (e.g., equivalent to a communication circuit) performs at least one of transmitting and receiving the wireless signal based on the determined polarization wave. Furthermore, the term "phase" hereafter can be used interchangeably with other terms such as "wireless communication," "period" in wireless communication, or "time interval." "Period" or "time interval" in wireless communication can also be understood as an example of "time resources." Additionally, "polarization wave," along with frequency resources and time resources, is also an example of resources in wireless communication.

[0131] Figure 8 This is a block diagram illustrating a structural example of a portion of a terminal 200 according to an embodiment of this disclosure. Figure 8 In the terminal 200 shown, the control unit 21 (e.g., equivalent to a control circuit) determines the polarization wave of the wireless signal in at least one of the first stage and the second stage following the first stage of wireless communication. The communication unit 22 performs at least one of transmitting and receiving the wireless signal based on the determined polarization wave.

[0132] [Base station structure]

[0133] Figure 9 This is a block diagram representing a structural example of base station 100. Figure 9The base station 100 shown includes, for example, a control unit 101, a data generation unit 102, a data transmission processing unit 103, a wireless transmission unit 104, an antenna 105, a wireless receiving unit 106, and a data reception processing unit 107. Furthermore, for example, Figure 9 The control unit 101, data generation unit 102, data transmission processing unit 103, and data reception processing unit 107 shown can be equivalent to Figure 7 The control unit 11 shown, Figure 9 The antenna 105, wireless transmitter 104, and wireless receiver 106 shown can be equivalent to Figure 7 The communication unit 12 is shown.

[0134] Control unit 101 controls, for example, the setting of polarization waves in at least one of transmission (in other words, downlink) and reception (in other words, uplink). For example, control unit 101 may also set the polarization wave for each cell, each beam, or each terminal 200 (in other words, the user). Furthermore, for example, control unit 101 may set dedicated polarization waves for each downlink and uplink, or it may set a polarization wave common to both downlink and uplink. Control unit 101 outputs, for example, polarization wave-related information (hereinafter referred to as "polarization wave information") for reception to reception data processing unit 107, outputs polarization wave information for transmission to transmission data processing unit 103, and outputs polarization wave information notified to terminal 200 to data generation unit 102.

[0135] The data generation unit 102 generates downlink data signals, such as user data, system information, or dedicated control information (e.g., RRC signaling or downlink control information (DCI)) related to the terminal 200, and outputs the generated downlink data signals to the data transmission processing unit 103. For example, the data generation unit 102 may generate downlink data signals based on polarization wave information input from the control unit 101, or it may generate downlink data signals that include polarization wave information.

[0136] The transmission data processing unit 103 encodes and modulates the downlink data signal input from the data generation unit 102. Furthermore, the transmission data processing unit 103 performs transmission polarization processing (e.g., right-hand circularly polarized wave, left-hand circularly polarized wave, or both) based on polarization information input from the control unit 101. The transmission data processing unit 103 then outputs the processed signal to the wireless transmission unit 104.

[0137] The wireless transmitter 104 performs wireless transmission processing such as D / A (Digital / Analog) conversion, up-conversion, and amplification on the signal input from the transmission data processing unit 103, and transmits the processed wireless signal from the antenna 105.

[0138] The wireless receiver 106 performs wireless reception processing such as down-conversion and A / D (Analog / Digital) conversion on the data signal received from the terminal 200 via the antenna 105, and outputs the wirelessly processed received signal to the receiving data processing unit 107.

[0139] The receiving data processing unit 107 performs receiving polarization processing on the received signal, for example, based on the polarization information input from the control unit 101. Furthermore, the receiving data processing unit 107 demodulates and decodes the received signal and outputs the received data. In addition, the receiving polarization processing may include, for example, a process to separate the polarization waves (de-polarization) by multiplying the polarization vectors of the right-hand circularly polarized wave and the left-hand circularly polarized wave.

[0140] [Terminal Structure]

[0141] Figure 10 This is a block diagram representing a structural example of terminal 200. Figure 10 The terminal 200 shown includes, for example, an antenna 201, a wireless receiver 202, a data receiving and processing unit 203, a control unit 204, a data generating unit 205, a data transmitting and processing unit 206, and a wireless transmitter 207. Furthermore, for example, Figure 10 The control unit 204, data generation unit 205, data transmission processing unit 206, and data reception processing unit 203 shown can be equivalent to Figure 8 The control unit 21 shown, Figure 10 The antenna 201, wireless transmitter 207, and wireless receiver 202 shown can be equivalent to Figure 8 The communication unit 22 is shown.

[0142] The wireless receiving unit 202 performs wireless receiving processing such as down-conversion and A / D conversion on the data signal received from the base station 100 via the antenna 201, and outputs the wirelessly received signal to the receiving data processing unit 203.

[0143] The receiving data processing unit 203 performs receiving polarization processing (e.g., depolarization) on the received signal based on the polarization information input from the control unit 204. Additionally, the receiving data processing unit 203 demodulates and decodes the received signal and outputs, for example, polarization information contained in the received data to the control unit 204.

[0144] The control unit 204, for example, determines the polarization wave set for at least one of reception (in other words, downlink) and transmission (in other words, uplink) based on polarization wave information input from the receiving data processing unit 203, or information already specified in a standard (or specification). Alternatively, the control unit 204 may also determine, for example, to use a pre-defined (in other words, set) polarization wave during the period before notification of receiving polarization wave information from the base station 100 during initial access (or, also called "initial connection"). The control unit 204, for example, outputs polarization wave information for reception to the receiving data processing unit 203 and polarization wave information for transmission to the transmitting data processing unit 206.

[0145] The data generation unit 205 generates, for example, an uplink data signal containing user data or feedback information, and outputs the generated downlink data signal to the data transmission processing unit 206.

[0146] The transmission data processing unit 206 encodes and modulates the downlink data signal input from the data generation unit 205. Additionally, the transmission data processing unit 206 performs transmission polarization processing (e.g., right-hand rotation, left-hand rotation, or both) based on polarization information input from the control unit 204. The transmission data processing unit 206 then outputs the processed signal to the wireless transmission unit 207.

[0147] The wireless transmission unit 207 performs wireless transmission processing such as D / A conversion, up-conversion, and amplification on the signal input from the transmission data processing unit 206, and transmits the processed wireless signal from the antenna 201.

[0148] [Example of operation of base station 100 and terminal 200]

[0149] This section describes the operation of the base station 100 and terminal 200.

[0150] In this embodiment, at least for the communication channels and signals during initial access, a predefined polarization wave is set.

[0151] On the other hand, for channels and signals used in processes different from the initial access, such as channels and signals assigned to each user, a polarization wave is set, for example, by the base station 100 notifying the terminal 200. Furthermore, if the base station 100 does not notify the terminal 200, the terminal 200 may, for example, set a pre-defined polarization wave.

[0152] Figure 11 This is a sequence diagram representing an example of initial access.

[0153] For example, base station 100 sends a synchronization signal block (SSB) to terminal 200. Terminal 200 obtains synchronization and common cell parameters with base station 100 from the received SSB. The SSB may include, for example, synchronization signals such as primary synchronization signal (PSS) and secondary synchronization signal (SSS), as well as a broadcast channel (physical broadcast channel (PBCH)).

[0154] Next, terminal 200 receives system information broadcast by the system information block (SIB) sent from base station 100.

[0155] For example, during initial access (in other words, random access procedure), terminal 200 sends a preamble signal (e.g., also known as "Physical Random Access Channel (PRACH)" or "Msg.1") to base station 100 based on the resources specified by system information.

[0156] Base station 100 receives PRACH and sends a response signal (e.g., also referred to as "RACH response" or "Msg.2") to terminal 200 in response to PRACH. The RACH response may be sent, for example, in a downlink data channel (e.g., Physical Downlink Shared Channel (PDSCH)).

[0157] Next, terminal 200 responds based on RACH, for example by sending an RRC message (or, referred to as "Msg.3") containing a connection request to base station 100.

[0158] Base station 100 sends an RRC message (or, referred to as "Msg.4") containing a response signal for Msg.3 to terminal 200.

[0159] In this embodiment, as described above, during initial access, at least the SSB and SIB are given fixed polarization waves. Terminal 200, for example, determines the fixed polarization waves as the polarization waves of the SSB and SIB.

[0160] Furthermore, fixed polarization waves can be predefined in standards (or specifications) or set by the system. A fixed polarization wave can be, for example, either a right-hand circularly polarized wave or a left-hand circularly polarized wave, or both.

[0161] On the other hand, in this embodiment, for example, the polarization of other channels and signals different from SSB and SIB can be determined (in other words, set or notified) based on information sent from base station 100 to terminal 200.

[0162] The following will explain methods 1 to 3 for determining polarization waves as examples.

[0163] <Method 1>

[0164] In Method 1, polarization is controlled by cell or beam. Additionally, in Method 1, the polarization information set for each cell or beam is communicated to terminal 200 by the SIB.

[0165] For example, in Figure 11 In this process, terminal 200 obtains polarization information from SIB and determines the polarization wave shown by the obtained polarization information as the polarization wave in the communication after PRACH transmission (e.g., at least one of transmission and reception). Furthermore, terminal 200 can also set different polarization waves for transmission (i.e., uplink) and reception (i.e., downlink).

[0166] Figure 12 This is a flowchart illustrating an example of the processing of terminal 200 in method 1.

[0167] exist Figure 12 In this process, terminal 200, for example, searches for (in other words, detects) a Special Segment Bus (SSB) during initial access (S101). For example, if the polarization wave used by the SSB is known, terminal 200 (e.g., data processing unit 203) searches for the SSB based on that polarization wave (e.g., a fixed polarization wave). On the other hand, if the polarization wave is not known, terminal 200 may, for example, switch between a non-polarized wave, a right-hand circularly polarized wave, and a left-hand circularly polarized wave to search for the SSB (in other words, blind determination), or it may search for the SSB through polarization wave diversity reception.

[0168] If no SSB is detected (S102: No), terminal 200 returns to the process in S101 and repeatedly searches for SSBs. On the other hand, if an SSB is detected (S102: Yes), terminal 200 receives an SIB (S103). For example, terminal 200 (e.g., receiving data processing unit 203) can receive SIBs based on a fixed polarization wave. Terminal 200 obtains, for example, cell operation parameters and polarization wave information from the received SIB.

[0169] Terminal 200 sets the obtained polarization wave, for example, as a polarization wave for receiving processing (in other words, downlink processing) and transmitting processing (in other words, uplink processing) (S104). For example, after obtaining the polarization wave information, terminal 200 sets the polarization wave to receiving data processing unit 203 and transmitting data processing unit 206.

[0170] Furthermore, even if the SIB does not contain polarization wave information, the terminal 200 can still perform communication after receiving the SIB based on a fixed polarization wave.

[0171] Additionally, base station 100 can also use SIB to notify each terminal group of its polarization. Terminal groups are formed, for example, based on the type of terminal 200 or the terminal ID of terminal 200 (e.g., cell-radio network temporary identifier (C-RNTI)). By using different polarizations for each terminal group, polarization-based multiplexing transmission can be performed.

[0172] Additionally, base station 100 can also include information about the correspondence between SSB numbers and polarization waves, such as information about which beam uses which polarization wave, in the SIB broadcast to the cell. Thus, terminal 200 can determine the polarization wave used by beams within the cell, and therefore can use the appropriate polarization wave when measuring adjacent beams (e.g., L1-RSRP (Layer 1 Reference Signal Received Power) measurements), thereby enabling rapid measurement.

[0173] In addition to notifying the polarization information of a specific cell or beam, base station 100 can also use SIB to notify the polarization information of surrounding cells or beams. For example, terminal 200 can obtain the polarization information used by surrounding cells or beams, thus enabling rapid measurements for handover or beam switching. Furthermore, during handover or beam switching, the polarization information of the next cell or beam can be included in the handover notification beforehand. Therefore, terminal 200 will obtain the polarization information to be used next in advance, allowing for rapid handover or beam switching.

[0174] In this way, terminal 200 may, for example, determine a fixed polarization wave as the polarization wave for wireless communication until the SIB is received, and determine the polarization wave represented by the SIB notified by base station 100 as the polarization wave for wireless communication after the SIB is received.

[0175] Based on the polarization wave notified by the SIB, the base station 100 can flexibly set the polarization wave by cell or by beam, thus, for example, suppressing inter-cell interference (or, referred to as "inter-beam interference"). Furthermore, throughput can be improved by multiplexing the polarization wave based on this polarization wave.

[0176] In addition, in method 1, base station 100 can notify multiple terminals 200 of polarization wave information at one time using SIB, on a cell or beam basis, thus reducing the amount of resources consumed in notifying polarization waves.

[0177] In addition, in method 1, by utilizing the polarization wave notification of SIB, the polarization wave can also be notified to the terminal 200 in the RRC idle (RRC_IDLE) state or the RRC inactive (RRC_INACTIVE) state. Therefore, the polarization wave of each cell or each beam can also be set for the data (e.g., paging data or RACH response) received by the terminal 200 in the RRC idle state or the RRC inactive state.

[0178] Furthermore, for example, information about the polarization of the PRACH channel that the terminal transmits first during initial access can be notified in parameters such as IE RACH-ConfigCommon, IE RACH-ConfigDedicated, IE RACH-ConfigCommonGeneric (which are RRC parameters), or in prach-ConfigurationIndex (which specifies the PRACH format). In this case, the terminal 200 can obtain the polarization information at the same time as obtaining the PRACH format or transmission resources. Additionally, different polarizations can be notified depending on the type of RACH processing, such as contention-based RACH or non-contention-based RACH (CFRA: Contention-Free Random Access).

[0179] Furthermore, when the system band is divided into multiple frequencies using component carriers (CCs) or bandwidth parts (BWPs), the base station 100 can also notify the terminal 200 of the polarization information of each CC or each BWP. In this case, the terminal 200 can also receive SSBs or SIBs based on fixed polarizations in the frequency band containing CCs or BWPs, and receive or transmit user data based on the polarizations notified by the SIBs in the CCs or BWPs allocated for user data communication. Additionally, CCs are sometimes also referred to as "cells," "primary cells (PCells)," "secondary cells (SCells)," "primary SCells (PSCells)," "master cell groups (MCGs)," and "secondary cell groups (SCGs)," etc. In addition, when the CC or BWP is set by the terminal, the base station 100 can also notify the terminal 200 of dedicated RRC control information containing polarization wave information whenever the CC or BWP is set or changed.

[0180] Alternatively, base station 100 can pre-determine the polarization wave of the beam covering a ground area (e.g., an area defined by longitude and latitude coordinates) and notify terminal 200 of multiple beam information containing location information and polarization wave information. In this case, a terminal capable of obtaining location information via GNSS (Global Navigation Satellite System) can determine the polarization wave based on its own location. Therefore, it is not necessary to notify the polarization wave every time the beam is switched, thereby reducing the amount of control information.

[0181] <Method 2>

[0182] In method 2, the polarization wave is controlled by terminal 200.

[0183] For example, base station 100 can use high-layer signaling dedicated to terminal 200 (e.g., dedicated RRC signaling) to notify each terminal 200 of the polarization wave information.

[0184] During initial access, for example in Figure 11 In Msg.4 shown, a dedicated RRC control message is sent. For example, in Figure 11In this process, terminal 200 obtains polarization information from Msg.4 and determines the polarization wave shown in the obtained polarization information as the polarization wave in subsequent communications (e.g., at least one of transmission and reception) after receiving Msg.4. Furthermore, terminal 200 can also set different polarization waves for transmission and reception. Alternatively, different polarization waves can be set according to the physical channel.

[0185] Additionally, terminal 200 in RRC idle or RRC inactive state does not receive dedicated RRC control information. Therefore, terminal 200 may also use a fixed polarization (e.g., the same polarization as SSB or SIB) for data received in RRC idle or RRC inactive state (e.g., paging data or RACH response).

[0186] Figure 13 This is a flowchart illustrating an example of the processing of terminal 200 in method 2.

[0187] exist Figure 13 In this process, for example, during initial access, terminal 200 searches for (in other words, detects) an SSB (S201). If no SSB is detected (S202: No), terminal 200 returns to the process in S201 and repeatedly searches for an SSB. On the other hand, if an SSB is detected (S202: Yes), terminal 200 receives an SIB (S203). In addition, terminal 200 performs RACH processing (e.g., transmission and reception of Msg.1 to Msg.4) (S204).

[0188] Terminal 200 can, for example, communicate based on a fixed polarization wave during the process from S201 (searching for SSB) to S204 (RACH processing). Additionally, for example, terminal 200 obtains polarization wave information from Msg.4.

[0189] Terminal 200 sets the obtained polarization wave, for example, as a polarization wave for receiving processing (in other words, downlink processing) and transmitting processing (in other words, uplink processing) (S205). For example, after obtaining the polarization wave information, terminal 200 sets the polarization wave to receiving data processing unit 203 and transmitting data processing unit 206.

[0190] Furthermore, if Msg.4 (e.g., dedicated RRC control information) does not contain polarization information, terminal 200 can also perform communication after receiving Msg.4 based on a fixed polarization. Additionally, for example, if dedicated RRC control information containing polarization information is received in communication after Msg.4, terminal 200 can also use the polarization notified by the dedicated RRC control information in communication after receiving the dedicated RRC control information.

[0191] Thus, in method 2, for example, terminal 200 determines a fixed polarization wave (e.g., the same polarization wave as SSB or SIB) as the polarization wave for wireless communication up to Msg.4, and determines a polarization wave represented by dedicated RRC control information received from base station 100 as the polarization wave for wireless communication after receiving Msg.4.

[0192] Base station 100 can flexibly set the polarization wave according to the polarization wave notified by dedicated RRC control information for terminal 200, thus, for example, suppressing inter-cell interference (or inter-beam interference). In addition, since a polarization wave dedicated to terminal 200 can be set, for example, the throughput can be improved by utilizing polarization wave multiplexing transmission between terminals 200 (e.g., also called "inter-UE multiplexing").

[0193] As an example of the polarization wave set for terminal 200, a circularly polarized wave can also be set for terminal 200 using satellite communication (e.g., very small aperture terminal (VSAT) system) or phased array, while a linearly polarized wave can be set for terminal 200 with lower capability (e.g., Internet of Things (IoT) terminal).

[0194] Additionally, the base station 100 can also set the same polarization wave for multiple terminals 200 within a cell or beam, for example, in the polarization wave settings of each terminal 200. By setting the polarization wave, for example, the polarization wave of each cell or each beam can be set, thus suppressing inter-cell interference (or inter-beam interference).

[0195] Alternatively, in Method 2, instead of dedicated RRC control information, a MAC control element (MAC CE) can be used to notify each terminal 200 of its polarization wave.

[0196] Furthermore, although the case of notifying each terminal 200 of the polarization wave in Msg.4 has been described, it is not limited to this; for example, the polarization wave of each terminal 200 can also be notified in Msg.2. Additionally, Figure 11 This indicates the case of a four-step RACH, but it is not limited to this. For example, in the case of using a two-step RACH imported in Rel.16, the polarization wave can also be notified in Msg.B. Msg.B is the response to the PRACH and the PUSCH containing Msg.A, and it contains data including the RACH response and the RRC message.

[0197] <Method 3>

[0198] In method 3, the polarization wave is controlled according to the data from terminal 200.

[0199] For example, base station 100 can notify terminal 200 of the polarization information of each data item by notifying control information (e.g., downlink control information (DCI)) that is being allocated to terminal 200. Terminal 200 obtains the polarization information from the DCI, for example, and determines the polarization shown in the obtained polarization information as the polarization in subsequent communications (e.g., at least one of transmission and reception) after receiving the DCI. Furthermore, the polarization of the signal transmitting the DCI (e.g., PDCCH) can also be a fixed polarization (e.g., a predefined polarization or a polarization set by the cell).

[0200] Figure 14 This is a flowchart illustrating an example of the processing of terminal 200 in method 3.

[0201] exist Figure 14 In this process, for example, during initial access, terminal 200 searches for (in other words, detects) an SSB (S301). If no SSB is detected (S302: No), terminal 200 returns to the process in S301 and repeatedly searches for an SSB. On the other hand, if an SSB is detected (S302: Yes), terminal 200 receives an SIB (S303). Additionally, terminal 200 receives a DCI (S304).

[0202] Terminal 200 may, for example, communicate based on a fixed polarization wave during the process from S301 (searching for SSB) to S304 (receiving DCI). Additionally, for example, terminal 200 obtains the polarization wave information contained in the DCI.

[0203] Terminal 200 sets the obtained polarization wave, for example, as a polarization wave for data reception processing (in other words, downlink processing) or data transmission processing (in other words, uplink processing) (S305).

[0204] Next, the terminal 200 receives or transmits data based on the set polarization wave (S306).

[0205] Furthermore, even if the DCI does not contain polarization wave information, the terminal 200 can still perform data communication after receiving the DCI based on a fixed polarization wave.

[0206] Here, in the notification methods using DCI to notify polarized waves, there are methods such as adding a bit representing the polarized wave to the DCI (e.g., called a "polarization wave notification bit") for notification, methods using downlink transmission configuration information (e.g., transmission configuration indicator (TCI) status) for notification, or methods using precoding information (e.g., transmitted precoding matrix indicator (TPMI)) for notification. In other words, the polarized wave indicated by the DCI can be represented, for example, by the polarization wave notification bit, TCI status, precoding information, or antenna port notification.

[0207] The following describes an example of a notification method that utilizes polarization wave notification bits, TCI status, precoded information, or antenna port notification.

[0208] <Notification Method Using Polarized Wave Notification Bits>

[0209] For example, a polarization notification bit can be added to the DCI that notifies at least one of the downlink and uplink data allocations.

[0210] For example, the downlink-assigned DCI (or DCI format) may be DCI format 1_0 or DCI format 1_1, while the uplink-assigned DCI (or DCI format) may be DCI format 0_0 or DCI format 0_1.

[0211] For example, polarization notification bits can be included in each DCI format. Alternatively, polarization notification bits can be included in a subset of DCI formats (e.g., corresponding to DCI format 1_1 and DCI format 0_1 ​​with two or more layers). This reduces the overhead of control information.

[0212] Alternatively, polarization notification bits can be included in the DCI sent from the terminal-dedicated search space, while other DCIs (e.g., DCIs sent from the public search space) may not contain polarization notification bits. Thus, the terminal 200 can obtain polarization information within its dedicated search space.

[0213] Alternatively, for example, the presence or absence of polarization notification bits in each DCI can be specified in the standard (or specification), or the presence or absence of polarization notification bits in each DCI can be notified to the terminal 200 using SIB or terminal-specific RRC control information. For example, when using SIB to notify of the presence or absence of polarization notification bits, the polarization of the transmission and reception of a specific Msg from Msg.1 to Msg.4 in the RACH processing can be notified. Alternatively, when using terminal-specific RRC control information to notify of the presence or absence of polarization notification bits, the polarization of the transmission and reception of data after Msg.4 in the RACH processing can be notified.

[0214] Alternatively, the presence or absence of the polarization notification bit can be set according to the terminal 200. For example, the presence or absence of the polarization notification bit can also be switched according to the type of terminal 200. For example, a terminal 200 with a fixed large antenna such as a parabolic antenna or a phased array can be set to have a polarization notification bit (in other words, the polarization can be controlled), while a terminal 200 with a portable small antenna such as a patch antenna can be set to have no polarization notification bit (in other words, the polarization is not controlled).

[0215] In this way, by using polarization wave notification bits to notify polarization waves, it is possible, for example, to avoid interference caused by polarization waves in the transmission of each terminal 200.

[0216] Furthermore, by using polarization notification bits to notify the polarization wave, the polarization wave can be set, for example, based on the data transmission of terminal 200. This allows for more flexible application of polarization wave multiplexing transmission between terminals 200 (e.g., multiplexing between UEs) or polarization wave multiplexing transmission for the same terminal 200 (e.g., intra-UE multiplexing). For example, the polarization wave can be switched based on the location or propagation conditions of terminal 200, either by terminal 200 itself or by the data transmission of terminal 200. For instance, polarization wave multiplexing transmission can be performed for terminals 200 located near the center of a cell or beam, while for terminals 200 located at the cell edge or beam edge, interference can be avoided by using a polarization wave different from that of neighboring cells or beams, thereby improving system throughput.

[0217] <Notifications using TCI status>

[0218] In Rel.15, for example, the TCI state is used to inform the terminal 200 of the identification information (e.g., SSB ID or channel state information reference signal (CSI-RS) ID) of the signal (e.g., reference signal) referenced when transmitting or receiving data.

[0219] Therefore, in this embodiment, the base station 100 includes polarization wave information in the TCI state for notification.

[0220] In TCI state, the channel characteristics (e.g., Doppler shift or delay) that terminal 200 can refer to when transmitting or receiving data are defined as "QCL". For example, multiple QCL types are defined according to the category of the referable channel characteristics.

[0221] In method 3, for example, a polarization wave is added to the referenced channel characteristics contained in the QCL type. For example, the polarization wave can be set in the QCL type contained in the TCI state transmitted from base station 100 to terminal 200. Through this setting, for example, the polarization wave used for the reference signal corresponding to SSB ID or CSI-RS ID and the polarization wave used for data are associated.

[0222] For example, such as Figure 15 As shown, a "QCL type E" corresponding to a polarized wave can also be defined as a QCL type. Additionally, as... Figure 16 As shown, QCL type E (e.g., type E) can also be set as QCL type (e.g., qcl-Type) in the RRC message related to TCI status and QCL.

[0223] Furthermore, for example, the polarization wave for each SSB ID can be set using the method based on this embodiment or Embodiment 2 or Embodiment 3 described later. Additionally, for example, the polarization wave for each CSI-RS ID can be explicitly notified using an RRC message (e.g., CSI-ResourceConfig) set by CSI-RS, or implicitly notified. For example, in the case of implicit notification, one of the right-hand circularly polarized waves and the left-hand circularly polarized wave can be notified using an even-numbered ID in the CSI-RS ID, and the other can be notified using an odd-numbered ID; or the notification can be performed using the most significant bit or the least significant bit.

[0224] Additionally, base station 100 can utilize the TCI state to notify terminal 200 of information related to multiple QCLs (e.g., a set of SSB IDs or CSI-RSIDs and QCL types). For example, the polarization waveform can be set for terminal 200 more flexibly through the notification described below.

[0225] Notification Method A:

[0226] For example, when setting polarization waves on a beam-by-beam (or cell-by-cell) basis, or when a terminal uses a specific polarization wave, base station 100 can notify the TCI status associated with the SSB ID and the polarization wave. That is, in addition to the SSB ID, base station 100 also includes the polarization wave information in the TCI status information during notification.

[0227] Notification Method B:

[0228] For example, in the case of multiplexed transmission of polarized waves among application terminals 200, base station 100, for instance, notifies the TCI status associated with a CSI-RS ID and a polarized wave. That is, in addition to the CSI-RS ID, base station 100 also includes the polarized wave information in the TCI status information during notification. At this time, base station 100, for instance, notifies the multiple terminals 200 that are multiplexed to transmit polarized waves of the CSI-RS ID associated with different polarized waves respectively.

[0229] Notification Method C:

[0230] For example, when using the same terminal 200 for polarization multiplexing transmission, the base station 100 may notify the TCI status associated with two CSI-RS IDs and polarizations. That is, the base station 100 includes the information of multiple CSI-RS IDs and each polarization in the TCI status information in the notification.

[0231] Terminal 200 may, for example, determine one of the notification methods A to C based on the reference signal (e.g., SSB or CSI-RS) notified by the TCI state and the number of sets of reference signals (e.g., CSI-RS) and QCL types notified by the TCI state. In other words, terminal 200 may also determine the method of utilizing the polarized wave (e.g., reuse or polarized wave multiplexing transmission) based on the TCI state.

[0232] Alternatively, the TCI status information can be notified in the RRC message (e.g., an RRC reconfiguration message) or MAC CE instead of in the DCI. When the TCI status is notified in the RRC message or MAC CE, terminal 200 continues to use the polarization wave notified by the MAC CE for a certain period. Base station 100 may also notify the TCI status using the RRC message or MAC CE, for example, during handover or beam (defined by the SSB) switching. Furthermore, base station 100 may, for example, pre-notify multiple candidate TCI states available in the RRC message and activate the TCI state to be used using the MAC CE. Alternatively, base station 100 may select a TCI state from the multiple TCI states notified by the RRC message or MAC CE according to data allocation and notify terminal 200 using the DCI.

[0233] In addition, Figure 15 The example shown illustrates the case where QCL type E is defined to correspond to a polarized wave, but polarization can also be included in the channel characteristics corresponding to at least one of QCL types A to D.

[0234] <Notification using precoded information>

[0235] For example, the "precoded information" notified by the DCI can also be used to notify polarized waves.

[0236] For example, the precoding information for dual-antenna ports can also be specified in Table 7.3.1.1.2-4 of 3GPP TS 38.212 V15.6.0 (e.g., refer to...). Figure 17 In the three states of ), the polarization wave is notified.

[0237] For example, it can also be like Figure 17 As shown, a bit field (bit field mapped to index) of '0' indicates a right-hand circularly polarized wave (RHCP), a bit field of '1' indicates a left-hand circularly polarized wave (LHCP), and a bit field of '2' indicates multiplexing of both RHCP and LHCP.

[0238] Terminal 200, for example, will be with Figure 17 The polarization wave corresponding to the value (bit value) indicated by the bit field of the precoded information shown is determined as the polarization wave of the wireless signal. In other words, the terminal 200 replaces the information notified by the precoded information with polarization wave information.

[0239] <Notification via antenna port>

[0240] For example, as specified in Tables 7.3.1.2.2-1 to 7.3.1.2.2-4 of 3GPP TS 38.212 V15.6.0, 4 to 6 bits are used in the DCI to notify the antenna port information. The notification of the antenna port can also be used to notify the polarization wave. For example, the antenna port number can be pre-assigned to the polarization wave, and the notification of the antenna port number can be used to notify the polarization wave. Alternatively, the value of the "Antenna port(s)" field notified by the DCI can be used to notify the polarization wave. Furthermore, when notifying antenna ports of two layers, it can be pre-determined that the first layer is a right-hand circularly polarized wave (RHCP) and the second layer is a left-hand circularly polarized wave (LHCP), thereby reducing the amount of notification information. Terminal 200 reads the antenna port information as polarization wave information and transmits it using the specified polarization wave.

[0241] The above illustrates an example of a notification method utilizing polarization wave notification bits, TCI status and precoding information, and antenna port notification bits.

[0242] Based on these notification methods, it is possible to flexibly notify polarized waves, for example, by utilizing existing notification mechanisms.

[0243] Alternatively, base station 100 may also notify the polarization wave by using the allocated DCI (e.g., transmitted in the PDCCH) to notify Msg.2. Based on this notification, terminal 200 may be able to use the notified polarization wave in communications following Msg.2, for example.

[0244] Furthermore, the method of using DCI to notify polarization waves is not limited to these methods; other bits within the DCI can also be used to notify polarization wave information. Additionally, for example, besides the DCI used for data allocation, a Group Common DCI, such as DCI Format 2, can be used to notify polarization wave notification bits. Thus, base station 100 can simultaneously notify the terminal group of polarization wave information, thereby reducing control information overhead.

[0245] In addition, the polarization wave information notified by DCI can be set to be valid for PDSCH or PUSCH allocated by DCI, or it can be set to be valid for channels or signals that are allocated to terminal 200 after the notification by DCI until the notification of polarization wave information with different content to terminal 200.

[0246] Thus, in method 3, for example, terminal 200 determines a fixed polarization wave as the polarization wave for wireless communication until the DCI is received, and determines the polarization wave represented by the DCI received from base station 100 as the polarization wave for wireless communication after the DCI is received.

[0247] Based on the polarization wave notified by DCI, base station 100 can flexibly set the polarization wave according to terminal 200 or according to data, thus, for example, suppressing inter-cell interference (or inter-beam interference). Furthermore, because dedicated polarization waves can be set according to terminal 200 or according to data, for example, throughput can be improved by utilizing polarization wave multiplexing transmission between terminals 200 or polarization wave multiplexing transmission between data within the same terminal 200.

[0248] The above explains methods 1 through 3.

[0249] As described above, in this embodiment, the base station 100 and the terminal 200 determine, for example, the polarization wave used in at least a portion of the initial access wireless communication (e.g., equivalent to the first phase) and the wireless communication after the initial access (e.g., equivalent to the second phase).

[0250] For example, terminal 200 determines a fixed polarization wave (e.g., a predefined polarization wave) as the polarization wave of the channel or signal in the initial access (e.g., SSB and SIB), thereby enabling signal reception using a reception method corresponding to the fixed polarization wave. Thus, terminal 200 can, for example, reduce the processing load by suppressing the complexity of communication processing, thereby improving reception performance. Furthermore, for example, terminal 200 can reduce the signaling required to notify polarization wave information by using a fixed polarization wave.

[0251] In addition, in this embodiment, for example, the terminal 200 sets a polarization wave notified by the base station 100 for the channel or signal used by user data that occupies more time or frequency resources than the initial access.

[0252] Terminal 200 can use a predefined polarized wave or a polarized wave notified by base station 100 to perform communication processing based on a communication method (e.g., at least one of sending and receiving) corresponding to the polarized wave set for terminal 200, thereby improving the communication performance of terminal 200.

[0253] Furthermore, by notifying the polarization wave, the terminal 200 can determine the method of utilizing the polarization wave (e.g., either reuse or multiplexing the polarization wave for transmission). Therefore, for example, interference can be avoided by reusing the polarization wave, and throughput can be improved by using multiplexing the polarization wave for transmission.

[0254] Therefore, according to this embodiment, the resources (e.g., polarized waves) used by the terminal 200 for communication can be appropriately determined.

[0255] Furthermore, for example, a fixed polarization wave can be predefined in the standard, or a fixed polarization wave can be freely set through operation. In the case of setting through operation, the terminal 200 can also detect the polarization wave by blind determination during the initial connection, and then wait for a signal using the same polarization wave.

[0256] (Implementation Method 2)

[0257] 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.

[0258] In this embodiment, the polarization wave set for each cell is associated with the cell's identification information (e.g., also referred to as "cell ID" or "physical cell identifier (PCI)").

[0259] For example, during the initial SSB search during access, terminal 200 detects the PSS and SSS within the SSB and determines the cell ID. Then, terminal 200 receives the PBCH within the SSB and obtains the system information broadcast to the cell.

[0260] In this embodiment, the terminal 200 may, for example, set the polarization associated with the cell ID during (or after) the SSB search.

[0261] For example, regarding the association between cell IDs and polarization, even-numbered cell IDs can be associated with right-hand circularly polarized (RHCP) waves, and odd-numbered cell IDs with left-hand circularly polarized (LHCP) waves. In other words, cell IDs with a least significant bit of 0 can be associated with RHCP, and cell IDs with a least significant bit of 1 can be associated with left-hand circularly polarized (LHCP) waves. Furthermore, the associations between even-numbered and odd-numbered cell IDs and RHCP and LHCP can be reversed.

[0262] Alternatively, for example, cell IDs with smaller number ranges (e.g., the first half of the cell ID) can be associated with right-hand circularly polarized (RHCP) waves, and cell IDs with larger number ranges (e.g., the second half of the cell ID) can be associated with left-hand circularly polarized (RHCP) waves. In other words, for example, cell IDs with a most significant bit of 0 can be associated with RHCP waves, and cell IDs with a most significant bit of 1 can be associated with left-hand circularly polarized (RHCP) waves.

[0263] Figure 18 This is a flowchart illustrating an example of the processing of the terminal 200 in this embodiment.

[0264] For example, when searching for an SSB, terminal 200 uses a right-hand circularly polarized wave for reception, such as during the process of detecting the PSS or SSS of the cell ID corresponding to the right-hand circularly polarized wave (RHCP) (S401). If a cell ID corresponding to the right-hand circularly polarized wave (RHCP) is detected (S402: Yes), terminal 200 sets the right-hand circularly polarized wave as a polarization wave for, for example, for reception processing (in other words, downlink processing) and transmission processing (in other words, uplink processing) (S405).

[0265] On the other hand, if no PSS or SSS corresponding to the cell ID of the right-hand circularly polarized wave (RHCP) is detected (S402: No), the terminal 200, for example, uses the left-hand circularly polarized wave for reception during the detection of the PSS or SSS corresponding to the cell ID of the left-hand circularly polarized wave (LHCP) (S403). If a cell ID corresponding to the left-hand circularly polarized wave (LHCP) is detected (S404: Yes), the terminal 200 sets the left-hand circularly polarized wave as a polarization wave for, for example, for reception processing (in other words, downlink processing) and transmission processing (in other words, uplink processing) (S405).

[0266] If, for example, no SSB is detected (S404: No), terminal 200 returns to the processing of S401 and repeatedly searches for SSB.

[0267] Next, terminal 200 receives SIB (S406) for example, according to the polarization wave set based on cell ID.

[0268] Thus, in this embodiment, the terminal 200 can determine the polarization associated with the cell ID by detecting the cell ID during cell search. Therefore, since the base station 100 does not need to notify the polarization information, the signaling overhead of the control information used to notify the polarization information can be reduced.

[0269] Furthermore, in this embodiment, even for SSB, communication can be carried out based on polarization waves based on cell ID. Therefore, polarization waves can be used to avoid interference in more channels.

[0270] In addition, Figure 18 The document explains that when terminal 200 searches for an SSB, it performs PSS or SSS reception processing based on the polarization wave associated with the cell ID being searched (e.g., Figure 18The processing described in S401 or S404 is possible, but not limited to. For example, terminal 200 may also determine the cell ID by searching the SSB and determine the polarization associated with the determined cell ID as the polarization for communication after the cell ID is detected (e.g., after receiving the PBCH contained in the SSB). In this case, for example, for the channels used to determine the cell ID, namely PSS and SSS, fixed polarizations (e.g., predefined polarizations) can be set in the same way as in embodiment 1. In addition, since the PBCH is transmitted in the same block as PSS and SSS, the same polarization as PSS and SSS can also be set.

[0271] (Implementation Method 3)

[0272] 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.

[0273] In this embodiment, the polarization wave set for each beam is associated with the identification information of the SSB corresponding to that beam (e.g., also referred to as "SSB ID" or "SSB index").

[0274] For example, in this embodiment, the terminal 200 may also set a polarization wave associated with the SSB ID of the detected SSB.

[0275] For example, even-numbered SSB IDs can be associated with right-hand circularly polarized (RHCP) waves, and odd-numbered SSB IDs with left-hand circularly polarized (LHCP) waves. In other words, an SSB ID with its least significant bit set to 0 can be associated with RHCP, and an SSB ID with its least significant bit set to 1 can be associated with LHCP. Furthermore, the associations between even-numbered and odd-numbered SSB IDs and RHCP and LHCP can be reversed.

[0276] Alternatively, for example, SSB IDs with smaller number ranges (e.g., the first half of the SSB ID) can be associated with right-hand circularly polarized waves (RHCP), and SSB IDs with larger number ranges (e.g., the second half of the SSB ID) can be associated with left-hand circularly polarized waves. In other words, for example, SSB IDs with a highest bit of 0 can be associated with right-hand circularly polarized waves (RHCP), and SSB IDs with a highest bit of 1 can be associated with left-hand circularly polarized waves.

[0277] Here, for example in NR Rel.15, the most significant bit (MSB) of the SSB ID is indicated by the PBCH DMRS (reference signal used for PBCH demodulation), and the least significant bit (LSB) is indicated by the data section of the PBCH. For example, terminal 200 can determine the MSB of the SSB ID at the time the PBCH DMRS is detected. On the other hand, terminal 200 cannot determine the LSB of the SSB ID until the data section of the PBCH is decoded and analyzed.

[0278] Therefore, for example, the polarization notification can also correspond to the high-order bit side of the SSB ID (e.g., MSB). Based on this correspondence, the terminal 200 can determine the polarization associated with the SSB ID before decoding the data section of the PBCH, and thus can receive the data section of the PBCH based on the polarization inherent to the cell or beam.

[0279] Figure 19 This is a flowchart illustrating an example of the processing of the terminal 200 in this embodiment.

[0280] Terminal 200 may, for example, search (in other words, detect) the PSS or SSS contained in the SSB (S501). In the detection of PSS or SSS, terminal 200 may search based on a fixed polarization wave, or may switch between a non-polarized wave, a right-hand circularly polarized wave, and a left-hand circularly polarized wave (in other words, blind determination), or may search through polarization wave diversity reception.

[0281] If, for example, no PSS or SSS is detected (S502: No), terminal 200 returns to the processing of S501 and repeatedly searches for PSS or SSS.

[0282] If a PSS or SSS is detected (S502: Yes), terminal 200 detects the SSB ID (or, SSB index) (S503). Terminal 200 may detect the SSB ID from the PBCH DMRS (e.g., the high-order bits of the SSB ID) or from the data section of the PBCH (e.g., the low-order bits of the SSB ID).

[0283] Terminal 200 sets the polarization associated with the detected SSB ID as, for example, a polarization used for receiving processing (in other words, downlink processing) and transmitting processing (in other words, uplink processing) (S504).

[0284] Next, the terminal 200 decodes the PBCH data based on the set polarization wave (S505) and receives the SIB (S506).

[0285] Thus, in this embodiment, the terminal 200 can determine the polarization associated with the SSB ID by detecting the SSB ID. Therefore, since the base station 100 does not need to notify the polarization information, the signaling overhead of the control information used to notify the polarization information can be reduced.

[0286] Furthermore, in this embodiment, even during the initial access processing after SSB ID detection (e.g., reception of PBCH or SIB), communication can be performed based on the polarization wave associated with the SSB ID. For example, when the MSB of the SSB ID is associated with the polarization wave, the terminal 200 can perform communication processing based on the polarization wave associated with the SSB ID during processing after receiving the data section of the PBCH. Additionally, when the LSB of the SSB ID is associated with the polarization wave, the terminal 200 can perform communication processing based on the polarization wave associated with the SSB ID during processing after receiving the SIB. Therefore, according to this embodiment, interference can be avoided by utilizing polarization waves in more channels.

[0287] The above describes various embodiments of this disclosure.

[0288] Furthermore, satellite communication systems include "regenerative" systems where the base station function resides on a satellite; and "transparent" systems where the base station function resides at a ground-based GW (Gateway), and the satellite receives signals from the GW, performs frequency conversion and amplification, and then transmits them. One embodiment of this disclosure can be applied to either the regenerative or transparent type.

[0289] In addition, in the above embodiments, a cell can be an area defined based on the received power of SSB or CSI-RS transmitted by a base station (e.g., satellite), or it can be an area defined based on geographical location.

[0290] In addition, in each embodiment, as an example, an example of a circularly polarized wave is described, but the polarized wave can also be a linearly polarized wave (e.g., at least one of a vertically polarized wave and a horizontally polarized wave) or other polarized waves such as a circularly polarized wave.

[0291] Alternatively, the various implementation methods (and methods) can be combined. For example, base station 100 can notify the polarization wave of each cell based on implementation method 2, and further notify the polarization wave of each terminal 200 based on method 3 of implementation method 1. Additionally, as a method for notifying polarization waves based on implementation method 1, base station 100 can also notify the polarization wave information for downlink data based on the TCI state based on method 3, and notify the polarization wave information for uplink data based on precoding information based on method 3. Furthermore, for example, downlink data can be set on a cell-by-cell basis based on implementation method 2, and uplink data can be set based on DCI notification of method 3 of implementation method 1.

[0292] In addition, in various embodiments, the terminal 200 may also store the polarization wave information detected by blind determination or the polarization wave information that is notified during the initial access. Then, for example, when the power of the terminal 200 is turned off, or when it enters the RRC idle state, the terminal 200 sets the polarization wave for transmission and reception based on the stored polarization wave information.

[0293] Furthermore, while the above embodiments have been described using NTN environments (e.g., satellite communication environments), this disclosure is not limited thereto. This disclosure can also be applied to other communication environments (e.g., terrestrial cellular environments of LTE and / or NR).

[0294] Furthermore, in the above embodiments, for example, the following situation was described: the terminal 200 sets a fixed polarization wave during the period before receiving notification of polarization wave information, and sets a polarization wave based on the notification during the period after receiving notification of polarization wave information, but it is not limited to this. For example, the terminal 200 may also apply the polarization wave notified by the base station 100 to at least one channel or signal after receiving notification of polarization wave information. As an example, the terminal 200 may also set the polarization wave notified by the SIB during user data communication instead of during RACH processing. In this case, the terminal 200 may, for example, set a fixed polarization wave during RACH processing. In addition, for example, the terminal 200 may also switch between a fixed polarization wave and a polarization wave notified by the base station 100 according to the type of channel or signal.

[0295] Furthermore, in the above embodiments, it was explained that the terminal 200 sets a polarization wave (e.g., a fixed polarization wave and a polarization wave notified by the base station 100) in both the initial access and post-initial access processing, but it is not limited to this. For example, the terminal 200 may also apply the polarization wave in at least one of the initial access and post-initial access processing. As an example, it is also possible that the polarization wave is not applied in the initial access, but applied in the post-initial access processing. As another example, it is also possible that the polarization wave is not applied in the processing until the polarization wave information is notified by the base station 100, but applied in the processing after the polarization wave information is notified by the base station 100.

[0296] Alternatively, polarized wave information can be communicated only by satellites, base stations, or wireless systems using polarized waves. Alternatively, notification can be based on terminal capabilities from the terminal itself, and can be sent only to terminals with NTN or satellite communication capabilities. Terminal capabilities can also be communicated to the base station by the terminal using UE capability, UE feature, Subscriber Profile ID, etc.

[0297] In addition, the term "terminal" in the above embodiments can be replaced with the term "UE". Furthermore, the term "base station" can be replaced with "eNodeB", "eNB", "gNodeB", or "gNB".

[0298] In addition, expressions such as "...part" in the above embodiments can also be replaced with other expressions such as "...circuitry", "...device", "...unit" or "...module".

[0299] This switch can be implemented via software, hardware, or software in collaboration with hardware. The functional blocks used in the above embodiments are implemented partially or entirely as LSIs (Large Scale Integrations), and the processes described in the above embodiments can also be controlled partially or entirely 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 referred to as an "IC (Integrated Circuit)," "System LSI," "Super LSI," or "Ultra LSI."

[0300] The method of integrating the LSI is not limited to LSI; it can also be implemented using dedicated circuits, general-purpose processors, or special-purpose processors. Alternatively, it can utilize a programmable FPGA (Field Programmable Gate Array) manufactured using the LSI, or a reconfigurable processor that can reconfigure the connections or settings of the circuit blocks within the LSI. This disclosure can also be implemented for digital or analog processing.

[0301] 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.

[0302] This disclosure 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.

[0303] Communication devices are not limited to portable or mobile 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.

[0304] 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.

[0305] In addition, the communication device also includes devices such as controllers or sensors that are connected or linked to a communication device performing the communication functions described in this disclosure. For example, it includes a controller or sensor that generates control signals or data signals used by the communication device to perform the communication functions of the communication device.

[0306] 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.

[0307] A terminal according to one embodiment of this disclosure includes: a control circuit that determines a polarization wave to be used in at least one of a first wireless communication and a second wireless communication, the second wireless communication being a wireless communication following the first wireless communication; and a communication circuit that performs the wireless communication of the at least one using the determined polarization wave.

[0308] In one embodiment of this disclosure, the control circuit determines a predefined polarization wave as the polarization wave used for the first wireless communication.

[0309] In one embodiment of this disclosure, the control circuit determines the polarization wave for the second wireless communication based on information received from the base station.

[0310] In one embodiment of this disclosure, the information is system information, and the control circuit determines the polarization wave indicated by the system information as the polarization wave for the second wireless communication after receiving the system information.

[0311] In one embodiment of this disclosure, the information is terminal-specific higher-layer signaling, and the control circuit determines the polarization wave indicated by the higher-layer signaling as the polarization wave for the second wireless communication after receiving the higher-layer signaling.

[0312] In one embodiment of this disclosure, the information is downlink control information, and the control circuit determines the polarization wave for the second wireless communication after receiving the downlink control information based on the polarization wave represented by the downlink control indication.

[0313] In one embodiment of this disclosure, the polarization wave indicated by the downlink control information is indicated by downlink transmission setting information or information related to precoding.

[0314] In one embodiment of this disclosure, the information is cell identification information, which is associated with the polarization wave.

[0315] In one embodiment of this disclosure, the information is identification information of a synchronization signal corresponding to the beam, and the identification information of the synchronization signal is associated with the polarization wave.

[0316] In one embodiment of this disclosure, a bit of the plurality of bits of the identification information constituting the synchronization signal, which is included in the demodulation reference signal of the broadcast channel, is associated with the polarization wave.

[0317] In a communication method according to one embodiment of this disclosure, a terminal performs the following steps: determining a polarization wave to be used in at least one of a first wireless communication and a second wireless communication, wherein the second wireless communication is a wireless communication following the first wireless communication; and performing the wireless communication of the at least one using the determined polarization wave.

[0318] The entire contents of the description, drawings and abstract of the description contained in Japanese Patent Application No. 2019-202108, filed on November 7, 2019, are incorporated herein by reference.

[0319] Industrial applicability

[0320] One aspect of this disclosure is useful for wireless communication systems.

[0321] Explanation of reference numerals in the attached figures

[0322] 100 base stations

[0323] 101, 204 Control Department

[0324] Data Generation Departments 102 and 205

[0325] Data Processing Department (103, 206)

[0326] 104, 207 Wireless Transmission Unit

[0327] 105, 201 antennas

[0328] 106, 202 Wireless Receiving Unit

[0329] 107, 203 Receiving Data Processing Department

[0330] 200 terminals

Claims

1. A communication system comprising a terminal and a base station, The terminal includes: The receiving circuit receives polarization wave information from the base station for uplink transmission and / or downlink transmission for wireless communication. The polarization wave information includes at least one of left-hand circularly polarized wave information (LHCP information), right-hand circularly polarized wave information (RHCP information), and linearly polarized wave information. as well as The communication circuit uses the polarization wave indicated in the received polarization wave information to perform the wireless communication. in, The receiving circuit receives the polarization wave information, which includes polarization wave information of surrounding cells. The communication circuit uses the polarization wave indicated in the received polarization wave information of the surrounding cells to perform radio measurements of the surrounding cells. The base station includes: The base station's transmitting circuit sends the polarization wave information to the terminal; and The communication circuit of the base station uses the polarization wave indicated in the transmitted polarization wave information to perform the wireless communication.

2. The communication system as described in claim 1, wherein, The polarization wave information is system information. The communication circuit of the terminal uses the polarization wave indicated by the system information.

3. The communication system as described in claim 1, wherein, The polarization information of the surrounding cells is indicated along with the channel state information reference signal information, i.e., CSI-RS information.

4. The communication system as described in claim 1, wherein, The wireless communication includes a first wireless communication and / or a second wireless communication, wherein the second wireless communication is a wireless communication following the first wireless communication.

5. The communication system as described in claim 4, wherein, In the first wireless communication, the communication circuit of the terminal uses a specified polarization wave. In the second wireless communication, the communication circuit of the terminal uses the polarization wave based on the polarization wave information received from the base station.

6. The communication system as described in claim 1, wherein, The polarization wave information is terminal-specific higher-layer signaling. In the wireless communication following the receipt of the higher-layer signaling, the communication circuit of the terminal uses a polarized wave indicated by the higher-layer signaling.

7. The communication system as described in claim 1, wherein, The polarization wave information is downlink control information. In the wireless communication following the receipt of the downlink control information, the communication circuit of the terminal uses a polarized wave indicated by the downlink control information.

8. The communication system as described in claim 7, wherein, The polarization wave indicated by the downlink control information is indicated by downlink transmission setting information or information related to precoding.

9. The communication system as claimed in claim 1, wherein, The polarization wave information is the cell's identification information. The identification information of the cell is associated with the polarization wave.

10. The communication system as claimed in claim 1, wherein, The polarization wave information is the identification information of the synchronization signal corresponding to the beam. The identification information of the synchronization signal is associated with the polarization wave.

11. The communication system as claimed in claim 10, wherein, The bits of the identification information constituting the synchronization signal, which are included in the demodulation reference signal of the broadcast channel, are associated with the polarization wave.

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