Terminal, base station, communication method and integrated circuit

Abstract

This terminal is provided with: a control circuit that determines a polarized wave using at least one among first wireless communication and second wireless communication after the first wireless communication; and a communication circuit that performs at least one wireless communication using the determined polarized wave.

Description

[Technical field]

[0001] The present disclosure relates to a terminal and a communication method. [Background technology]

[0002] In the standardization of 5G, new radio access technology (NR) was discussed at 3GPP, and the NR Release 15 (Rel.15) specifications were published. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] 3GPP, TR38.811 V15.2.0, “Study on New Radio (NR) to support non terrestrial networks (Release 15),” 2019-09 [Non-Patent Document 2] 3GPP TSG RAN WG1 #98bis, R1-1911003, “On physical layer control procedures for NTN,” October, 2019 Summary of the Invention

[0004] However, in a wireless communication system, there is room for improvement in the method of determining the polarization to be used for wireless communication.

[0005] Non-limiting embodiments of the present disclosure contribute to providing a terminal and a communication method capable of appropriately determining the polarization to be used in wireless communication.

[0006] A terminal according to one embodiment of the present disclosure includes a control circuit that determines a polarization to be used in at least one of a first wireless communication and a second wireless communication subsequent to the first wireless communication, and a communication circuit that performs the at least one wireless communication using the determined polarization.

[0007] These comprehensive or specific aspects may be realized as a system, an apparatus, a method, an integrated circuit, a computer program, or a recording medium, or may be realized as any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium.

[0008] According to an embodiment of the present disclosure, it is possible to appropriately determine the polarization to be used for wireless communication.

[0009] Further advantages and benefits of an embodiment of the present disclosure will become apparent from the specification and drawings. Such advantages and / or benefits may be provided by some of the embodiments and features described in the specification and drawings, respectively, but not necessarily all of them may be provided to obtain one or more identical features. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is an example architecture diagram of a 3GPP NR system. [Diagram 2] Schematic diagram showing the functional separation between NG-RAN (Next Generation - Radio Access Network) and 5GC (5th Generation Core) [Diagram 3] Sequence diagram of RRC (Radio Resource Control) connection setup / reconfiguration procedure [Figure 4] A schematic diagram showing the usage scenarios of enhanced Mobile BroadBand (eMBB), massive Machine Type Communications (mMTC), and Ultra Reliable and Low Latency Communications (URLLC). [Diagram 5] Block diagram illustrating an example 5G system architecture for a non-roaming scenario [Figure 6]A diagram showing an example of a method for reusing resources. [Figure 7] FIG. 1 is a block diagram showing a configuration of a part of a base station according to a first embodiment; [Figure 8] FIG. 1 is a block diagram showing a partial configuration of a terminal according to a first embodiment; [Figure 9] FIG. 1 is a block diagram showing an example of a configuration of a base station according to a first embodiment; [Figure 10] FIG. 1 is a block diagram showing an example of a configuration of a terminal according to a first embodiment; [Figure 11] An example of initial access [Figure 12] A flowchart showing an example of the operation of a terminal according to the method 1 of the first embodiment. [Figure 13] A flowchart showing an example of the operation of a terminal according to the method 2 of the first embodiment. [Figure 14] A flowchart showing an example of the operation of a terminal according to the method 3 of the first embodiment. [Figure 15] A diagram showing an example of quasi co-location (QCL) Type. [Figure 16] A diagram showing an example of radio resource control (RRC) messages related to TCI state and QCL. [Figure 17] A diagram showing an example of precoding information [Figure 18] Flowchart showing an example of the operation of a terminal according to the second embodiment [Figure 19] Flowchart showing an example of the operation of a terminal according to the third embodiment DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0012] <5G NR system architecture and protocol stack> 3GPP continues to work on the next release of the fifth generation of mobile phone technology (also known simply as "5G"), which includes the development of a new radio access technology (NR) that will operate in the frequency range up to 100 GHz. The first version of the 5G standard was completed at the end of 2017, which will allow for the prototyping and commercial deployment of 5G NR compliant devices (e.g. smartphones).

[0013] For example, the system architecture generally assumes a Next Generation - Radio Access Network (NG-RAN) with gNBs. The gNBs provide the UE-side termination of the NG radio access user plane (SDAP / PDCP / RLC / MAC / PHY) and control plane (RRC) protocols. The gNBs are connected to each other by an Xn interface. The gNBs are also connected to a Next Generation Core (NGC) by a Next Generation (NG) interface, more specifically to an Access and Mobility Management Function (AMF) (e.g., a specific core entity performing AMF) by an NG-C interface, and to a User Plane Function (UPF) (e.g., a specific core entity performing UPF) by an NG-U interface. The NG-RAN architecture is shown in Figure 1 (see, e.g., 3GPP TS 38.300 v15.6.0, section 4).

[0014] The NR user plane protocol stack (see, for example, 3GPP TS 38.300, section 4.4.1) includes the Packet Data Convergence Protocol (PDCP) (see section 6.4 of TS 38.300), Radio Link Control (RLC) (see section 6.3 of TS 38.300), and Medium Access Control (MAC) (see section 6.2 of TS 38.300) sublayers, which are terminated on the network side at the gNB. A new Access Stratum (AS) sublayer (Service Data Adaptation Protocol (SDAP)) is also introduced on top of PDCP (see, for example, 3GPP TS 38.300, section 6.5). A control plane protocol stack is also defined for NR (see, for example, TS 38.300, section 4.4.2). An overview of Layer 2 functions is given in section 6 of TS 38.300. The functions of the PDCP, RLC and MAC sublayers are listed in clauses 6.4, 6.3 and 6.2 of TS 38.300, respectively. The functions of the RRC layer are listed in clause 7 of TS 38.300.

[0015] For example, the Medium-Access-Control layer handles logical channel multiplexing and scheduling and scheduling-related functions, including handling various numerologies.

[0016] For example, the physical layer (PHY) is responsible for coding, PHY HARQ processing, modulation, multi-antenna processing, and mapping of signals to appropriate physical time-frequency resources. The physical layer also handles mapping of transport channels to physical channels. The physical layer provides services to the MAC layer in the form of transport channels. A physical channel corresponds to a set of time-frequency resources used for the transmission of a particular transport channel, and each transport channel is mapped to a corresponding physical channel. For example, the physical channels include the uplink physical channels PRACH (Physical Random Access Channel), PUSCH (Physical Uplink Shared Channel), and PUCCH (Physical Uplink Control Channel), and the downlink physical channels PDSCH (Physical Downlink Shared Channel), PDCCH (Physical Downlink Control Channel), and PBCH (Physical Broadcast Channel).

[0017] NR use cases / deployment scenarios may include enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine type communication (mMTC), which have diverse requirements in terms of data rates, latency, and coverage. For example, eMBB is expected to support peak data rates (20 Gbps in downlink and 10 Gbps in uplink) and user-experienced data rates that are about three times higher than those offered by IMT-Advanced. On the other hand, for URLLC, stricter requirements are imposed on ultra-low latency (0.5 ms for user plane latency in UL and DL respectively) and high reliability (1-10-5 within 1 ms). Finally, mMTC preferably requires high connection density (1,000,000 devices / km in urban environments). 2 ), wide coverage in hostile environments, and extremely long battery life (15 years) for a low-cost device.

[0018] Therefore, OFDM numerology (e.g., subcarrier spacing, OFDM symbol length, cyclic prefix (CP) length, number of symbols per scheduling interval) suitable for one use case may not be valid for other use cases. For example, low latency services may preferably require a shorter symbol length (and therefore a larger subcarrier spacing) and / or fewer symbols per scheduling interval (also called TTI) than mMTC services. Furthermore, deployment scenarios with large channel delay spreads may preferably require a longer CP length than scenarios with small delay spreads. Subcarrier spacing may be optimized accordingly to maintain similar CP overhead. NR may support one or more subcarrier spacing values. Correspondingly, subcarrier spacings of 15 kHz, 30 kHz, 60 kHz... are currently considered. The symbol length Tu and subcarrier spacing Δf are directly related by the formula Δf=1 / Tu. Similar to LTE systems, the term "resource element" can be used to mean the smallest resource unit consisting of one subcarrier for the length of one OFDM / SC-FDMA symbol.

[0019] In the new radio system 5G-NR, for each numerology and each carrier, a resource grid of subcarriers and OFDM symbols is defined for the uplink and downlink, respectively. Each element of the resource grid is called a resource element and is specified based on a frequency index in the frequency domain and a symbol position in the time domain (see 3GPP TS 38.211 v15.6.0).

[0020] <Functional separation between NG-RAN and 5GC in 5G NR> Figure 2 shows the functional separation between NG-RAN and 5GC. The logical node of NG-RAN is gNB or ng-eNB. 5GC has logical nodes AMF, UPF, and SMF.

[0021] For example, the gNB and ng-eNB host the following main functions: - Radio Resource Management functions such as Radio Bearer Control, Radio Admission Control, Connection Mobility Control, dynamic allocation (scheduling) of resources to UEs in both uplink and downlink; - IP header compression, encryption, and integrity protection of data; - Selection of the AMF at UE attach time if routing to the AMF cannot be determined from information provided by the UE; - Routing of user plane data towards the UPF; - Routing of control plane information towards AMF; - Setting up and tearing down connections; - Scheduling and sending paging messages; - Scheduling and transmission of system broadcast information (AMF or Operation, Admission, Maintenance (OAM) origin); - Configuration of measurements and measurement reporting for mobility and scheduling; - Transport level packet marking in the uplink; - Session management; - Support for network slicing; - Management of QoS flows and their mapping to data radio bearers; - Support for UEs in RRC_INACTIVE state; - NAS message delivery function; - Sharing of radio access networks; - Dual connectivity; - Close cooperation between NR and E-UTRA.

[0022] The Access and Mobility Management Function (AMF) hosts the following main functions: - Ability to terminate Non-Access Stratum (NAS) signalling; - NAS signaling security; - Access Stratum (AS) security control; - 3GPP Core Network (CN) inter-node signalling for mobility between access networks; - Reachability to idle mode UEs (including control and execution of paging retransmissions); - Managing the registration area; - Support for intra-system and inter-system mobility; - Access authentication; - Access authorization including roaming privilege checks; - Mobility management control (subscription and policies); - Support for network slicing; - Select the Session Management Function (SMF).

[0023] Additionally, the User Plane Function (UPF) hosts the following main functions: - anchor points for intra-RAT mobility / inter-RAT mobility (if applicable); - External PDU (Protocol Data Unit) Session Points for interconnection with data networks; - Packet routing and forwarding; - Packet inspection and policy rule enforcement for the user plane part; - Traffic usage reporting; - uplink classifier to support routing of traffic flows to the data network; - Branching Point for supporting multi-homed PDU session; - QoS processing for the user plane (e.g., packet filtering, gating, UL / DL rate enforcement); - Verification of uplink traffic (mapping to QoS flows of SDFs); - Downlink packet buffering and triggering function for downlink data notification.

[0024] Finally, the Session Management Function (SMF) hosts the following main functions: - Session management; - IP address allocation and management for the UE; - Selection and control of the UPF; - Traffic steering setting function in the User Plane Function (UPF) for routing traffic to the appropriate destination; - Enforcement of control plane policies and QoS; - Notification of downlink data.

[0025] <Procedures for RRC connection setup and reconfiguration> Figure 3 shows some of the interactions between the UE, gNB, and AMF (5GC entity) in the NAS part when the UE moves from RRC_IDLE to RRC_CONNECTED (see TS 38.300 v15.6.0).

[0026] RRC is a higher layer signaling (protocol) used for UE and gNB configuration. With this transition, the AMF prepares UE context data (which includes, for example, PDU session context, security keys, UE Radio Capability, UE Security Capabilities, etc.) and sends it to the gNB with an INITIAL CONTEXT SETUP REQUEST. The gNB then activates AS security together with the UE. This is done by the gNB sending a SecurityModeCommand message to the UE, and the UE responding with a SecurityModeComplete message to the gNB. The gNB then reconfigures to set up Signaling Radio Bearer 2 (SRB2) and Data Radio Bearer (DRB) by sending an RRCReconfiguration message to the UE and receiving an RRCReconfigurationComplete from the UE. For signaling-only connections, the steps related to RRCReconfiguration are omitted since SRB2 and DRB are not set up. Finally, the gNB informs the AMF that the setup procedure is complete with an INITIAL CONTEXT SETUP RESPONSE.

[0027] Therefore, the present disclosure provides an entity (e.g., AMF, SMF, etc.) of a 5th Generation Core (5GC), comprising: a control circuit that operatively establishes a Next Generation (NG) connection with a gNodeB; and a transmitter that operatively transmits an initial context setup message to the gNodeB via the NG connection so that a signaling radio bearer between the gNodeB and a User Equipment (UE) is set up. Specifically, the gNodeB transmits Radio Resource Control (RRC) signaling including a resource allocation configuration information element (IE) to the UE via the signaling radio bearer. Then, the UE transmits in uplink or receives in downlink based on the resource allocation configuration.

[0028] <IMT usage scenarios after 2020> Figure 4 shows some of the use cases for 5G NR. The 3rd generation partnership project new radio (3GPP NR) considers three use cases that were envisioned by IMT-2020 to support a wide variety of services and applications. The first phase of specifications for enhanced mobile-broadband (eMBB) has been completed. Current and future work includes standardization for ultra-reliable and low-latency communications (URLLC) and massive machine-type communications (mMTC), in addition to expanding support for eMBB. Figure 4 shows some examples of envisioned usage scenarios for IMT beyond 2020 (see e.g. ITU-R M.2083 Figure 2).

[0029] URLLC use cases have stringent requirements for performance such as throughput, latency, and availability. URLLC use cases are envisioned as one of the enabling technologies for future applications such as wireless control of industrial production or manufacturing processes, remote medical surgery, automation of power transmission and distribution in smart grids, and road safety. URLLC's ultra-high reliability is supported by identifying technologies that meet the requirements set by TR 38.913. Key requirements for NR URLLC in Release 15 include a target user plane latency of 0.5 ms on the UL (uplink) and 0.5 ms on the DL (downlink). The overall URLLC requirement for a single packet transmission is a block error rate (BLER) of 1E-5 for a packet size of 32 bytes with a user plane latency of 1 ms.

[0030] From a physical layer perspective, reliability can be improved in many possible ways. Current room for reliability improvement includes defining a separate CQI table for URLLC, more compact DCI formats, PDCCH repetition, etc. However, this room can be expanded to achieve ultra-high reliability as NR (with respect to the key requirements of NR URLLC) becomes more stable and more developed. Specific use cases for NR URLLC in Release 15 include augmented reality / virtual reality (AR / VR), e-health, e-safety, and mission-critical applications.

[0031] Also, technology enhancements targeted by NR URLLC aim at improving latency and improving reliability. Technology enhancements for improving latency include configurable numerology, non-slot-based scheduling with flexible mapping, grant-free (configured grant) uplink, slot-level repetition in data channel, and pre-emption in downlink. Pre-emption means that a transmission with already allocated resources is stopped and the already allocated resources are used for other transmissions with lower latency / higher priority requirements that are requested later. Thus, a transmission that was already allowed is preempted by a later transmission. Pre-emption is applicable regardless of the specific service type. For example, a transmission of service type A (URLLC) may be preempted by a transmission of service type B (eMBB, etc.). Technology enhancements for improving reliability include dedicated CQI / MCS tables for a target BLER of 1E-5.

[0032] The use case of mMTC (massive machine type communication) is characterized by a very large number of connected devices transmitting relatively small amounts of data that are typically not sensitive to delays. The devices are required to be low-cost and have a very long battery life. From an NR perspective, the use of very narrow bandwidth portions is one solution that allows UEs to save power and extend battery life.

[0033] As mentioned above, the scope of reliability improvement in NR is expected to be broader. One of the key requirements for all cases, e.g. for URLLC and mMTC, is high or ultra-high reliability. Several mechanisms can improve reliability from a radio perspective and a network perspective. In general, there are two to three key areas that can help improve reliability. These areas include compact control channel information, data channel / control channel repetition, and diversity with respect to frequency, time, and / or spatial domains. These areas are generally applicable to reliability improvement regardless of the specific communication scenario.

[0034] Further use cases with more stringent requirements are envisaged for NR URLLC, such as factory automation, transportation and power distribution, such as high reliability (up to 10-6 level of reliability), high availability, packet size up to 256 bytes, time synchronization up to a few μs (depending on the use case, the value can be 1 μs or a few μs depending on the frequency range and low latency in the order of 0.5 ms to 1 ms (e.g. 0.5 ms latency in the targeted user plane)).

[0035] Furthermore, for NR URLLC, several technical enhancements may be possible from the perspective of the physical layer. These technical enhancements include enhancements to the Physical Downlink Control Channel (PDCCH) related to compact DCI, repetition of the PDCCH, and increased monitoring of the PDCCH. Also, the enhancement of UCI (Uplink Control Information) is related to the enhancement of enhanced HARQ (Hybrid Automatic Repeat Request) and CSI feedback. Additionally, enhancements to the PUSCH related to mini-slot level hopping, and enhancements to retransmission / repetition may be possible. The term "mini-slot" refers to a Transmission Time Interval (TTI) that contains fewer symbols than a slot (a slot has 14 symbols).

[0036] <QoS Control> The QoS (Quality of Service) model of 5G is based on QoS flows and supports both QoS flows that require a guaranteed flow bit rate (GBR: Guaranteed Bit Rate QoS flows) and QoS flows that do not require a guaranteed flow bit rate (non-GBR QoS flows). Therefore, at the NAS level, a QoS flow is the finest-grained QoS differentiation in a PDU session. A QoS flow is identified within a PDU session by a QoS Flow ID (QFI) that is carried in an encapsulation header via the NG-U interface.

[0037] For each UE, the 5GC establishes one or more PDU sessions. For each UE, the NG-RAN establishes at least one Data Radio Bearer (DRB) for the PDU session, e.g. as shown above with reference to Fig. 3. Additional DRBs for the QoS flows of that PDU session can be configured later (when it is up to the NG-RAN). The NG-RAN maps packets belonging to different PDU sessions to different DRBs. The NAS level packet filters in the UE and 5GC associate UL and DL packets with QoS flows, whereas the AS level mapping rules in the UE and NG-RAN associate UL and DL QoS flows with DRBs.

[0038] Figure 5 shows the non-roaming reference architecture for 5G NR (see TS 23.501 v16.1.0, section 4.23). An Application Function (AF) (e.g., an external application server hosting 5G services as illustrated in Figure 4) interacts with the 3GPP core network to provide services, for example by accessing a Network Exposure Function (NEF) to support applications that affect traffic routing, or by interacting with a policy framework for policy control (e.g., QoS control) (see Policy Control Function (PCF)). Based on the operator's deployment, Application Functions that are considered trusted by the operator can interact directly with the relevant Network Functions. Application Functions that are not allowed by the operator to directly access the Network Functions interact with the relevant Network Functions using an exposure framework for external use via the NEF.

[0039] Figure 5 further illustrates further functional units of the 5G architecture: Network Slice Selection Function (NSSF), Network Repository Function (NRF), Unified Data Management (UDM), Authentication Server Function (AUSF), Access and Mobility Management Function (AMF), Session Management Function (SMF), and Data Network (DN, e.g., operator-provided services, Internet access, or third-party services). All or part of the core network functions and application services may be deployed and run in a cloud computing environment.

[0040] Therefore, the present disclosure provides an application server (e.g., an AF in a 5G architecture) comprising: a transmitter that, when operated, sends a request including QoS requirements for at least one of a URLLC service, an eMMB service, and an mMTC service to at least one of the 5GC functions (e.g., NEF, AMF, SMF, PCF, UPF, etc.) to establish a PDU session including a radio bearer between a gNodeB and a UE according to the QoS requirements; and a control circuit that, when operated, performs a service using the established PDU session.

[0041] [Expansion to non-terrestrial networks (NTN)] Rel. 15 is a specification for radio access technology for terrestrial networks, for example. On the other hand, the extension of NR to non-terrestrial networks (NTN: Non-Terrestrial Networks) such as communications using satellites or high-altitude platform stations (HAPS) is being considered (for example, Non-Patent Document 1).

[0042] In an NTN environment, the coverage area (e.g., one or more cells) of a satellite for a ground terminal or an aircraft terminal is formed, for example, by a beam transmitted from the satellite. Also, for example, a plurality of cells are formed by dividing the coverage area by transmitting a plurality of beams with sharp directionality from the satellite antenna. For example, when a terminal is moving, it communicates by switching cells by handover as in terrestrial cellular communication.

[0043] In addition, a single cell may be formed by bundling multiple beams from a satellite. In this case, in an NTN environment, for example, it is being considered to switch beams based on the mechanism of NR beam management (see, for example, Non-Patent Document 2).

[0044] Also, for example, by using different frequencies (or channels) between adjacent (or surrounding) beams or cells, "frequency reuse" can be realized. In frequency reuse, for example, different frequencies are used between adjacent beams or cells, so that inter-beam interference (in other words, inter-cell interference) can be reduced. For example, as shown in Fig. 6, in the case where three frequencies (for example, F1, F2, and F3) are used, frequency reuse 3 (or reuse 3) can be realized.

[0045] Also, for example, circular polarization is applied in satellite communications. For example, in addition to frequency reuse, interference between beams can be reduced by using different polarizations between adjacent beams. For example, as shown in Figure 6, reuse 4 can be achieved in the case of using two frequencies (e.g., F1 and F2) and two polarizations (e.g., right-handed circular polarization (RHCP) and left-handed circular polarization (LHCP)).

[0046] A method of reusing polarization (e.g., how to use polarization or which polarization to use) depends on, for example, network operation. Here, for example, if the polarization to be used is known at the receiving side (e.g., terminal or base station), it is possible to separate the polarization and receive signals even with a linear polarization antenna. On the other hand, even if the polarization to be used is unknown at the receiving side (e.g., terminal or base station), it is possible to receive signals of both polarizations (e.g., RHCP and LHCP) by receiving signals by, for example, diversity combining, but loss may occur.

[0047] Therefore, for example, if a terminal can determine the polarization to be used in a downlink signal, it can perform reception processing based on a reception method according to the polarization, thereby improving reception performance.

[0048] In addition, for example, since right-handed and left-handed circularly polarized waves are orthogonal to each other, the throughput can be improved by multiplexing signals using different circular polarizations (also called polarization multiplexing). In other words, circular polarization can be used for polarization multiplexing in addition to reusing resources.

[0049] However, in 5G NR (e.g., Rel. 15), there has been no sufficient consideration given to a method for determining (e.g., a notification method) the polarization or polarizations to be used in a terminal, or a method for using circular polarization.

[0050] Therefore, this disclosure describes a method for determining and using polarization in a terminal.

[0051] (Embodiment 1) [Wireless communication system overview] The wireless communication system according to an embodiment of the present disclosure 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 may be another wireless communication system. Both the base station 100 and the terminal 200 are examples of wireless communication devices.

[0052] FIG. 7 is a block diagram showing a configuration example of a part of a base station 100 according to an embodiment of the present disclosure. In the base station 100 shown in FIG. 7, a control unit 11 (e.g., corresponding to a control circuit) determines the polarization of a radio signal for a terminal 200 in at least one of a first phase in wireless communication and a second phase following the first phase. A communication unit 12 (e.g., corresponding to a communication circuit) performs at least one of transmission and reception of a radio signal based on the determined polarization. In the following, the term "phase" may be replaced with other terms such as "wireless communication", "period" or "time interval" in wireless communication. A "period" or "time interval" in wireless communication may be regarded as an example of a "time resource". In addition, "polarization" is an example of a resource in wireless communication, similar to frequency and time resources.

[0053] Fig. 8 is a block diagram showing a configuration example of a portion of terminal 200 according to an embodiment of the present disclosure. In terminal 200 shown in Fig. 8, control unit 21 (e.g., corresponding to a control circuit) determines the polarization of a radio signal in at least one of a first phase and a second phase following the first phase in wireless communication. Communication unit 22 performs at least one of transmission and reception of a radio signal based on the determined polarization.

[0054] [Base station configuration] Fig. 9 is a block diagram showing a configuration example of the base station 100. The base station 100 shown in Fig. 9 includes, for example, a control unit 101, a data generation unit 102, a transmission data processing unit 103, a wireless transmission unit 104, an antenna 105, a wireless reception unit 106, and a reception data processing unit 107. For example, the control unit 101, the data generation unit 102, the transmission data processing unit 103, and the reception data processing unit 107 shown in Fig. 9 may correspond to the control unit 11 shown in Fig. 7, and the antenna 105, the wireless transmission unit 104, and the wireless reception unit 106 shown in Fig. 9 may correspond to the communication unit 12 shown in Fig. 7.

[0055] The control unit 101 controls, for example, the setting of polarization in at least one of transmission (in other words, downlink) and reception (in other words, uplink). For example, the control unit 101 may set polarization for each cell, beam, or terminal 200 (in other words, user). Also, for example, the control unit 101 may set individual polarization for each of the downlink and uplink, or may set a common polarization for the downlink and uplink. For example, the control unit 101 outputs information on the polarization used for reception (hereinafter referred to as polarization information) to the reception data processing unit 107, outputs polarization information used for transmission to the transmission data processing unit 103, and outputs polarization information to be notified to the terminal 200 to the data generation unit 102.

[0056] The data generating unit 102 generates a downlink data signal such as user data, system information, or individual control information (e.g., RRC signaling or downlink control information (DCI)) related to each terminal 200, and outputs the generated downlink data signal to the transmission data processing unit 103. For example, the data generating unit 102 may generate a downlink data signal based on polarization information input from the control unit 101, or may generate a downlink data signal including polarization information.

[0057] The transmission data processing unit 103 encodes and modulates the downlink data signal input from the data generating unit 102. Furthermore, the transmission data processing unit 103 performs transmission polarization processing (for example, right-handed circular polarization, left-handed circular polarization, or both) based on, for example, polarization information input from the control unit 101. The transmission data processing unit 103 outputs the signal after transmission processing to the wireless transmitting unit 104.

[0058] The radio transmitting section 104 performs radio transmission processing such as D / A conversion, up-conversion, and amplification on the signal input from the transmission data processing section 103, and transmits the radio signal after the radio transmission processing from an antenna 105.

[0059] Radio receiving section 106 performs radio reception processing such as down-conversion and A / D conversion on the data signal received from terminal 200 via antenna 105, and outputs the received signal after radio reception processing to received data processing section 107.

[0060] The received data processing unit 107 performs, for example, a reception polarization process on the received signal based on the polarization information input from the control unit 101. The received data processing unit 107 also demodulates and decodes the received signal and outputs the received data. Note that the reception polarization process may include a process of separating the polarization (de-polarization) by, for example, multiplying the polarization vectors of the right-handed circular polarization and the left-handed circular polarization.

[0061] [Device configuration] Fig. 10 is a block diagram showing a configuration example of terminal 200. Terminal 200 shown in Fig. 10 includes, for example, antenna 201, wireless receiving unit 202, received data processing unit 203, control unit 204, data generation unit 205, transmission data processing unit 206, and wireless transmitting unit 207. Note that, for example, control unit 204, data generation unit 205, transmission data processing unit 206, and received data processing unit 203 shown in Fig. 10 may correspond to control unit 21 shown in Fig. 8, and antenna 201, wireless transmitting unit 207, and wireless receiving unit 202 shown in Fig. 10 may correspond to communication unit 22 shown in Fig. 8.

[0062] The radio receiving section 202 performs radio reception 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 received signal after the radio reception processing to the received data processing section 203.

[0063] The received data processing unit 203 performs, for example, reception polarization processing (for example, de-polarization) of the received signal based on the polarization information input from the control unit 204. In addition, the received data processing unit 203 demodulates and decodes the received signal, and outputs, for example, the polarization information included in the received data to the control unit 204.

[0064] The control unit 204 determines the polarization to be set in at least one of reception (in other words, downlink) and transmission (in other words, uplink) based on, for example, the polarization information input from the reception data processing unit 203 or information defined in a standard (or specification). Furthermore, the control unit 204 may determine the use of a polarization that is defined (in other words, set) in advance during a period before receiving a notification of polarization information from the base station 100, such as at the time of initial access (also called initial connection). The control unit 204 outputs, for example, the polarization information used for reception to the reception data processing unit 203, and outputs the polarization information used for transmission to the transmission data processing unit 206.

[0065] The data generating unit 205 generates an uplink data signal including, for example, user data or feedback information, and outputs the generated downlink data signal to the transmission data processing unit 206 .

[0066] The transmission data processing unit 206 encodes and modulates the downlink data signal input from the data generating unit 205. In addition, the transmission data processing unit 206 performs transmission polarization processing (for example, right-handed, left-handed, or both) based on, for example, polarization information input from the control unit 204. The transmission data processing unit 206 outputs the signal after transmission processing to the radio transmitting unit 207.

[0067] The radio transmitting section 207 performs radio transmission processing such as D / A conversion, up-conversion, and amplification on the signal input from the transmission data processing section 206 , and transmits the radio signal after the radio transmission processing from the antenna 201 .

[0068] [Example of Operation of Base Station 100 and Terminal 200] An example of the operation of base station 100 and terminal 200 described above will be explained.

[0069] In this embodiment, a predefined polarization is set for at least the channels and signals communicated during initial access.

[0070] On the other hand, for channels and signals communicated in a process different from the initial access, for example, channels and signals assigned to each user, for example, a polarization notified from base station 100 to terminal 200 is set. Note that when there is no notification from base station 100 to terminal 200, terminal 200 may set, for example, a polarization that is defined in advance.

[0071] FIG. 11 is a sequence diagram showing an example of the initial access.

[0072] For example, base station 100 transmits a synchronization signal block (SSB) to terminal 200, and terminal 200 acquires synchronization with base station 100 and common cell parameters from the received SSB. The SSB may include, for example, synchronization signals such as a primary synchronization signal (PSS) and a secondary synchronization signal (SSS), and a broadcast channel (physical broadcast channel (PBCH)).

[0073] Next, terminal 200 receives system information broadcast by a system information block (SIB) transmitted from base station 100.

[0074] For example, in initial access (in other words, a random access procedure), terminal 200 transmits a preamble signal (for example, also called a Physical Random Access Channel (PRACH) or Msg.1) to base station 100 based on resources specified in system information.

[0075] Base station 100 receives the PRACH and transmits a response signal to the PRACH (for example, also referred to as a RACH response or Msg.2) to terminal 200. The RACH response may be transmitted, for example, on a downlink data channel (for example, a Physical Downlink Shared Channel (PDSCH)).

[0076] Next, terminal 200 transmits, for example, an RRC message (also called Msg. 3) including a connection request to base station 100 based on the RACH response.

[0077] Base station 100 transmits to terminal 200 an RRC message (also referred to as Msg.4) including a response signal to Msg.3.

[0078] In this embodiment, as described above, in initial access, fixed polarization is set for at least the SSB and SIB. For example, terminal 200 determines the fixed polarization to be the polarization for the SSB and SIB.

[0079] The fixed polarization may be, for example, predefined in a standard (or specification) or may be set for each system. The fixed polarization may be, for example, either right-handed circular polarization or left-handed circular polarization, or both.

[0080] On the other hand, in this embodiment, polarization for channels and signals other than SSB and SIB may be determined (in other words, set or notified) based on information from base station 100 to terminal 200, for example.

[0081] Hereinafter, as an example, methods 1 to 3 for determining the polarization will be described respectively.

[0082] <Method 1> In method 1, polarization is controlled for each cell or beam. Also, in method 1, polarization information set for each cell or beam is notified to terminal 200 by the SIB.

[0083] 11, for example, terminal 200 acquires polarization information from the SIB and determines the polarization indicated in the acquired polarization information as the polarization in communication (for example, at least one of transmission and reception) after PRACH transmission. Note that different polarizations may be set for transmission (i.e., uplink) and reception (i.e., downlink) in terminal 200.

[0084] FIG. 12 is a flow diagram showing an example of processing of the terminal 200 according to the method 1.

[0085] 12, terminal 200 searches for (in other words, detects) an SSB, for example, at the time of initial access (S101). For example, when the polarization used for the SSB is known, terminal 200 (for example, received data processing unit 203) searches for the SSB based on the polarization (for example, fixed polarization). On the other hand, when the polarization is not known, terminal 200 may search for the SSB by switching between no polarization, right-handed circular polarization, and left-handed circular polarization (in other words, blind detection), or may search for the SSB by polarization diversity reception.

[0086] If the SSB is not detected (S102: No), the terminal 200 returns to the process of S101 and repeats the search for the SSB. On the other hand, if the SSB is detected (S102: Yes), the terminal 200 receives the SIB (S103). For example, the terminal 200 (for example, the received data processing unit 203) may receive the SIB based on a fixed polarization. The terminal 200 acquires, for example, the operation parameters and polarization information of the cell from the received SIB.

[0087] The terminal 200 sets the acquired polarization as the polarization to be used for, for example, reception processing (in other words, downlink processing) and transmission processing (in other words, uplink processing) (S104). For example, after acquiring the polarization information, the terminal 200 sets the polarization in the reception data processing unit 203 and the transmission data processing unit 206.

[0088] If the SIB does not include polarization information, terminal 200 may perform communication after receiving the SIB based on a fixed polarization.

[0089] Furthermore, base station 100 may notify the polarization for each terminal group by SIB. The terminal group is formed, for example, by the type of terminal 200 or the terminal ID of terminal 200 (for example, cell-radio network temporary identifier (C-RNTI) or the like). By using a different polarization for each terminal group, multiplexed transmission by polarization becomes possible.

[0090] In addition, base station 100 may include information on the correspondence between SSB numbers and polarizations, for example, information on which polarization is used in which beam, in the SIB broadcast in the cell. This allows terminal 200 to know the polarizations used in the beams in the cell, and therefore allows terminal 200 to use appropriate polarizations when measuring adjacent beams (for example, measuring L1-RSRP, etc.), and to perform the measurement quickly.

[0091] Furthermore, in addition to the polarization information of a certain cell or beam, the base station 100 may notify the polarization information of the neighboring cells or beams of the cell by the SIB. For example, the terminal 200 can grasp the polarization used in the neighboring cells or beams, and therefore can quickly perform measurement for handover or beam switching. Furthermore, at the time of handover or beam switching, the handover notification may include information on the polarization to be used in the next cell or beam in advance. This allows the terminal 200 to obtain information on the polarization to be used next in advance, and therefore enables quick handover or beam switching.

[0092] In this way, terminal 200, for example, determines a fixed polarization as the polarization to be used for wireless communication until the SIB is received, and determines the polarization indicated by the SIB notified from base station 100 as the polarization to be used for wireless communication after the SIB is received.

[0093] By using the polarization notified by the SIB, the base station 100 can flexibly set the polarization for each cell or each beam, so that, for example, inter-cell interference (also called inter-beam interference) can be suppressed. In addition, the throughput can be improved by polarization multiplexing based on this polarization.

[0094] Furthermore, in method 1, base station 100 can notify multiple terminals 200 of polarization information at once for each cell or beam using SIB, and therefore the amount of resources required for notifying polarization can be reduced.

[0095] In addition, in method 1, it is possible to notify terminal 200 in RRC_IDLE state or RRC_INACTIVE state of polarization by notifying the polarization via SIB, so that polarization can be set for each cell or beam for data (e.g., paging data or RACH response) received by terminal 200 in RRC_IDLE state or RRC_INACTIVE state.

[0096] In addition, the polarization information for the PRACH, which is the channel that is first transmitted at the time of initial access of the terminal, may be notified, for example, in RRC parameters IE RACH-ConfigCommon, IE RACH-ConfigDedicated, IE RACH-ConfigCommonGeneric, or prach-ConfigurationIndex, which is a parameter that specifies the format of the PRACH. In this case, the terminal 200 can simultaneously obtain the polarization information together with the format or transmission resource of the PRACH. In addition, it is also possible to notify different polarizations for each type of RACH processing, such as a contention-based RACH or a non-contention RACH (CFRA: Contention Free Random Access).

[0097] In addition, when the system band is divided into a plurality of frequencies using Component Carrier (CC) or Bandwidth Part (BWP), base station 100 may notify terminal 200 of polarization information for each CC or each BWP. In this case, terminal 200 may receive SSB or SIB based on a fixed polarization in a frequency band including CC or BWP, and may receive or transmit user data based on the polarization notified by SIB in CC or BWP assigned to communication of user data. In addition, CC may be called Cell, primary Cell (PCell), secondary Cell (SCell), Primary SCell (PSCell), Master Cell Group (MCG), Secondary Cell Group (SCG), etc. In addition, when CC or BWP is set for each terminal, base station 100 may notify terminal 200 of individual RRC control information including polarization information every time CC or BWP is set or changed.

[0098] Furthermore, the base station 100 may predetermine the polarization of the beam that covers each terrestrial area (for example, an area defined by longitude and latitude coordinates) and notify the terminal 200 of multiple beam information including position information and polarization information. In this case, a terminal that can acquire position information by GNSS or the like can know the polarization from its own position, so there is no need to notify the polarization every time the beam is switched, and the amount of control information can be reduced.

[0099] <Method 2> In method 2, the polarization is controlled for each terminal 200 .

[0100] For example, base station 100 may notify each terminal 200 of the polarization information for each terminal 200 by individual higher layer signaling (for example, dedicated RRC signaling) for each terminal 200.

[0101] At the time of initial access, for example, dedicated RRC control information is transmitted in Msg.4 shown in Fig. 11. For example, in Fig. 11, terminal 200 acquires polarization information from Msg.4, and determines the polarization indicated in the acquired polarization information as the polarization in communication (for example, at least one of transmission and reception) after reception of Msg.4. Note that different polarizations may be set for transmission and reception in terminal 200. Alternatively, different polarizations may be set for each physical channel.

[0102] Furthermore, terminal 200 in the RRC_IDLE state or the RRC_INACTIVE state does not receive dedicated RRC control information. Therefore, terminal 200 may use, for example, a fixed polarization (for example, the same polarization as that of SSB or SIB) for data (for example, paging data or RACH response) received in the RRC_IDLE state or the RRC_INACTIVE state.

[0103] FIG. 13 is a flow diagram showing an example of processing of the terminal 200 according to the method 2.

[0104] 13, terminal 200 searches for (in other words, detects) an SSB, for example, at the time of initial access (S201). If terminal 200 does not detect an SSB (S202: No), it returns to the process of S201 and repeats the search for an SSB. On the other hand, if terminal 200 detects an SSB (S202: Yes), it receives an SIB (S203). In addition, terminal 200 performs RACH processing (for example, transmitting and receiving Msg.1 to Msg.4) (S204).

[0105] Terminal 200 may perform communication based on a fixed polarization in the processes from S201 (SSB search) to S204 (RACH process), for example. Also, for example, terminal 200 acquires polarization information from Msg.4.

[0106] The terminal 200 sets the acquired polarization to, for example, the polarization to be used for reception processing (in other words, downlink processing) and transmission processing (in other words, uplink processing) (S205). For example, after acquiring the polarization information, the terminal 200 sets the polarization to the reception data processing unit 203 and the transmission data processing unit 206.

[0107] If polarization information is not included in Msg.4 (for example, individual RRC control information), terminal 200 may perform communication after receiving Msg.4 based on a fixed polarization. Also, if terminal 200 receives individual RRC control information including polarization information in communication after Msg.4, terminal 200 may use the polarization notified by the individual RRC control information in communication after receiving the individual RRC control information.

[0108] Thus, in method 2, for example, terminal 200 determines a fixed polarization (e.g., the same polarization as SSB or SIB) as the polarization to be used for wireless communication up to Msg.4, and determines the polarization indicated by the individual RRC control information received from base station 100 as the polarization to be used for wireless communication after Msg.4 is received.

[0109] By using the polarization notified by the individual RRC control information, the base station 100 can flexibly set the polarization for each terminal 200, thereby suppressing, for example, inter-cell interference (or inter-beam interference). In addition, since the polarization can be set for each terminal 200, the throughput can be improved by, for example, polarization multiplexing transmission between the terminals 200 (also called inter UE multiplexing).

[0110] As an example of polarization set for each terminal 200, circular polarization may be set for terminals 200 that use satellite communications (e.g., a very small aperture terminal (VSAT) system) or a phased array, and linear polarization may be set for terminals 200 that have lower capability (e.g., an internet of things (IoT) terminal).

[0111] Furthermore, the base station 100 may set the same polarization for multiple terminals 200 in a cell or a beam, for example, in setting the polarization for each terminal 200. This polarization setting makes it possible to set the polarization for each cell or beam, for example, and therefore it is possible to suppress inter-cell interference (or inter-beam interference).

[0112] Also, in method 2, the polarization for each terminal 200 may be notified by a MAC Control Element (MAC CE) instead of dedicated RRC control information.

[0113] Also, although a case has been described in which the polarization for each terminal 200 is notified in Msg.4, the present invention is not limited to this, and for example, the polarization for each terminal 200 may be notified in Msg.2. Also, although Fig. 11 shows a case of 4-step RACH, the present invention is not limited to this, and for example, when using 2-step RACH introduced in Rel.16, the polarization may be notified in Msg.B. Msg.B is a response to PUSCH including PRACH and Msg.A, and is data including a RACH response and an RRC message.

[0114] <Method 3> In method 3, the polarization is controlled for each piece of data from terminal 200.

[0115] For example, base station 100 may notify terminal 200 of polarization information for each data of terminal 200 by control information (e.g., downlink control information (DCI)) notifying allocation of data to terminal 200. Terminal 200, for example, acquires polarization information from DCI, and determines the polarization indicated in the acquired polarization information as the polarization in communication (e.g., at least one of transmission and reception) after reception of the DCI. Note that the polarization for a signal (e.g., PDCCH) transmitting DCI may be a fixed polarization (e.g., a polarization defined in advance, or a polarization set for each cell).

[0116] FIG. 14 is a flow diagram showing an example of processing of the terminal 200 according to the method 3.

[0117] 14, terminal 200 searches for (in other words, detects) an SSB, for example, at the time of initial access (S301). If terminal 200 does not detect an SSB (S302: No), terminal 200 returns to the process of S301 and repeats the search for an SSB. On the other hand, if terminal 200 detects an SSB (S302: Yes), terminal 200 receives an SIB (S303). Terminal 200 also receives a DCI (S304).

[0118] Terminal 200 may perform communication based on a fixed polarization in the processes from S301 (SSB search) to S304 (DCI reception), for example. Also, for example, terminal 200 obtains polarization information included in DCI.

[0119] The terminal 200 sets the acquired polarization as the polarization to be used for data reception processing (in other words, downlink processing) or data transmission processing (in other words, uplink processing) (S305).

[0120] Then, the terminal 200 receives or transmits data based on the set polarization (S306).

[0121] If DCI does not include polarization information, terminal 200 may perform data communication after receiving DCI based on a fixed polarization.

[0122] Here, the method of reporting polarization by DCI includes, for example, a method of reporting by adding a bit indicating polarization (e.g., referred to as a polarization reporting bit) in DCI, a method of reporting by downlink transmission configuration information (e.g., transmission configuration indication (TCI) state), or a method of reporting by precoding information (e.g., transmitted precoding matrix indicator (TPMI)). In other words, the polarization indicated by DCI is indicated by, for example, a polarization reporting bit, a TCI state, precoding information, or an antenna port report.

[0123] Below, an example of a notification method using the polarization notification bit, the TCI state, the precoding information, or the antenna port notification will be described.

[0124] <Notification method using polarization notification bit> For example, a polarization indication bit may be added to DCI indicating at least one of downlink and uplink data allocation.

[0125] For example, DCI (or DCI formats) for downlink allocation include DCI format 1_0 and 1_1, and DCI (or DCI formats) for uplink allocation include DCI format 0_0 and 0_1.

[0126] For example, each DCI format may include a polarization indication bit. Alternatively, some DCI formats (for example, DCI formats 1_1 and 0_1 corresponding to two or more layers) may include a polarization indication bit. This can reduce the overhead of control information.

[0127] Alternatively, the DCI transmitted by the terminal-specific search space may include a polarization notification bit, and other DCI (for example, DCI transmitted by a common search space) may not include a polarization notification bit. This allows terminal 200 to acquire polarization information in a search space specific to terminal 200.

[0128] Furthermore, the presence or absence of a polarization notification bit in each DCI may be specified in a standard (or specification), for example, and may be notified to terminal 200 by an SIB or terminal-specific RRC control information. For example, when the presence or absence of a polarization notification bit is notified by an SIB, it becomes possible to notify the polarization for transmission / reception of any of Msg.1 to Msg.4 in the RACH process. Also, when the presence or absence of a polarization notification bit is notified by terminal-specific RRC control information, it becomes possible to notify the polarization for data transmission / reception after reception of Msg.4 in the RACH process.

[0129] Also, for example, the presence or absence of the polarization notification bit may be set for each terminal 200. For example, the presence or absence of the polarization notification bit may be switched depending on the type of terminal 200. For example, the polarization notification bit may be set to be present (in other words, the polarization can be controlled) for terminal 200 having a fixed large antenna such as a parabolic antenna or a phased array, and the polarization notification bit may be set to be absent (in other words, the polarization is not controlled) for terminal 200 having a portable small antenna such as a patch antenna.

[0130] In this way, by notifying the polarization using the polarization notification bit, for example, it is possible to avoid interference due to polarization in transmission by each terminal 200.

[0131] Also, by notifying the polarization using the polarization notification bit, for example, the polarization can be set for each data transmission of the terminal 200. Therefore, polarization multiplexed transmission (e.g., inter UE multiplexing) between terminals 200 or polarization multiplexed transmission for the same terminal 200 (e.g., intra UE multiplexing) can be applied more flexibly. For example, the polarization may be switched for each terminal 200 or for each data transmission of the terminal 200 according to the location or propagation situation of the terminal 200. For example, polarization multiplexed transmission may be performed for the terminal 200 located near the center of the cell or beam, and for the terminal 200 located at the cell edge or beam edge, the system throughput can be improved by interference avoidance based on a polarization different from that of the adjacent cell or beam.

[0132] <Notification by TCI state> In Rel.15, for example, by the TCI state, the identification information (e.g., SSB ID or channel state information reference signal (CSI-RS) ID) of the signal (e.g., reference signal) that the terminal 200 refers to when transmitting or receiving data is notified.

[0133] Therefore, in this embodiment, the base station 100 notifies the TCI state including the polarization information.

[0134] In the TCI state, the channel characteristics (e.g., Doppler shift or delay) that the terminal 200 can refer to when transmitting or receiving data are defined as "QCL". For example, a plurality of QCL types are defined according to the type of channel characteristics that can be referred to.

[0135] In Method 3, for example, the polarization is added to the channel characteristics that can be referred to included in the QCL type. For example, the polarization can be set in the QCL type included in the TCI state transmitted from the base station 100 to the terminal 200. With this setting, for example, the polarization used for the reference signal corresponding to the SSB ID or CSI-RS ID is associated with the polarization used for the data.

[0136] For example, as shown in Fig. 15, "QCL type E" corresponding to polarization may be defined as one of the QCL types. Also, as shown in Fig. 16, in an RRC message regarding the TCI state and the QCL, QCL type E (e.g., type E) may be set as the QCL type (e.g., qcl-Type).

[0137] The polarization set for the SSB corresponding to each SSB ID may be set by, for example, this embodiment or a method based on embodiment 2 or 3 described below. The polarization set for the CSI-RS corresponding to each CSI-RS ID may be explicitly notified by, for example, an RRC message for CSI-RS configuration (e.g., CSI-ResourceConfig), or may be implicitly notified. For example, when implicitly notified, one of right-handed circular polarization and left-handed circular polarization may be notified by an even-numbered CSI-RS ID and the other may be notified by an odd-numbered CSI-RS ID, or may be notified by the most significant bit or the least significant bit.

[0138] Furthermore, base station 100 can use the TCI state to notify terminal 200 of information related to a plurality of QCLs (for example, a set of an SSB ID or CSI-RS ID and a QCL type). For example, the following notification can more flexibly set polarization for terminal 200.

[0139] Notification method A: For example, when the polarization is set on a beam-by-beam (or cell-by-cell) basis, or when one of the polarizations is used for each terminal, the base station 100 may notify the TCI state in which the SSB ID and the polarization are associated. In other words, the base station 100 notifies the TCI state information including the polarization information in addition to the SSB ID.

[0140] Notification method B: For example, when polarization multiplexing transmission is applied between terminals 200, base station 100 notifies, for example, a TCI state in which one CSI-RS ID and polarization are associated. That is, base station 100 notifies information on the TCI state including polarization information in addition to the CSI-RS ID. In this case, base station 100 notifies, for example, CSI-RS IDs associated with different polarizations to each of multiple terminals 200 that are subjected to polarization multiplexing transmission.

[0141] Notification method C: For example, when polarization multiplexing transmission is applied to the same terminal 200, base station 100 notifies, for example, a TCI state in which each of two CSI-RS IDs is associated with a polarization. In other words, base station 100 notifies information on the TCI state including multiple CSI-RS IDs and information on each polarization.

[0142] Terminal 200 may determine which of the above-mentioned reporting methods A to C to use, for example, based on a reference signal (for example, SSB or CSI-RS) reported in the TCI state and the number of sets of a reference signal (for example, CSI-RS) and a QCL type reported in the TCI state. In other words, terminal 200 may determine a method of using polarization (for example, reuse or polarization multiplexing transmission) based on the TCI state.

[0143] Note that the information on the TCI state may be notified in an RRC message (e.g., RRC reconfiguration message) or a MAC CE instead of in DCI. When the TCI state is notified in an RRC message or a MAC CE, the terminal 200 will continue to use the polarization notified by the MAC CE for a certain period. The base station 100 may notify the TCI state by an RRC message or a MAC CE, for example, at the time of handover or beam (beam defined by SSB) switching. Also, the base station 100 may notify a plurality of candidates for the TCI state that can be used in an RRC message, and activate the TCI state to be used by the MAC CE. Further, the base station 100 may select a TCI state for each data allocation from among the plurality of TCI states notified in the RRC message or the MAC CE, and notify the terminal 200 by DCI.

[0144] Also, in the example shown in FIG. 15, the case of defining QCL Type E corresponding to polarization has been described. However, for example, polarization may be included in the channel characteristics corresponding to at least one of QCL Type A to D.

[0145] <Notification by Precoding information> For example, polarization may be notified by the "Precoding information" notified in DCI.

[0146] For example, polarization may be notified in three states in the Precoding Information for two antenna ports defined in Table 7.3.1.1.2-4 in 3GPP TS 38.212 V15.6.0 (see FIG. 17 for example).

[0147] For example, as shown in FIG. 17, a bit field mapped to index of '0' may indicate right-hand circular polarization (RHCP), '1' may indicate left-hand circular polarization (LHCP), and '2' may indicate multiplex transmission of both right-hand circular polarization (RHCP) and left-hand circular polarization (LHCP).

[0148] Terminal 200 determines, for example, the polarization of the radio signal to be the polarization corresponding to the value (bit value) notified in the bit field of the precoding information shown in Fig. 17. In other words, terminal 200 interprets the information notified by the precoding information as polarization information.

[0149] <Notification by antenna port> For example, as specified in Table 7.3.1.2.2-1 to Table 7.3.1.2.2-4 of 3GPP TS 38.212 V15.6.0, antenna port information is notified in 4 to 6 bits by DCI. The polarization may be notified by this antenna port notification. For example, the antenna port number and the polarization may be associated in advance, and the polarization may be notified by notifying the antenna port number. Alternatively, the polarization may be notified by the value of the "Antenna port(s)" field notified by DCI. In addition, when antenna ports of two layers are notified, the amount of notified information may be reduced by determining in advance that the first layer is right-handed circular polarization (RHCP) and the second layer is left-handed circular polarization (LHCP). The terminal 200 converts the antenna port information into polarization information and transmits using the specified polarization.

[0150] An example of a notification method using the polarization notification bit, the TCI state, the precoding information, and the antenna port notification bit has been described above.

[0151] These notification methods allow for flexible notification of polarization, for example, by utilizing existing notification mechanisms.

[0152] Furthermore, base station 100 may notify the polarization, for example, by DCI (for example, transmitted in PDCCH) notifying the allocation of Msg.2. With this notification, terminal 200 can use the notified polarization in communication after Msg.2, for example.

[0153] Furthermore, the method of reporting polarization by DCI is not limited to these methods, and polarization information may be reported by other bits in DCI. Also, for example, in addition to the DCI used for data allocation, the polarization report bit may be reported using a terminal group common DCI such as DCI format 2. This allows base station 100 to report polarization information to terminal groups simultaneously, thereby reducing control information overhead.

[0154] In addition, the polarization information notified by DCI may be information valid for the PDSCH or PUSCH assigned by DCI, and may be information valid for the channel or signal assigned to terminal 200 after DCI is notified and until terminal 200 is notified of polarization information with different content.

[0155] Thus, in method 3, for example, terminal 200 determines a fixed polarization as the polarization to be used for wireless communication until reception of DCI, and determines the polarization indicated by the DCI received from base station 100 as the polarization to be used for wireless communication after the DCI is received.

[0156] By using the polarization notified by DCI, the base station 100 can flexibly set the polarization for each terminal 200 or for each data, so that, for example, inter-cell interference (or inter-beam interference) can be suppressed. Also, since an individual polarization can be set for each terminal 200 or for each data, for example, the throughput can be improved by polarization multiplexing transmission between terminals 200 or polarization multiplexing transmission between data in the same terminal 200.

[0157] Methods 1 to 3 have been described above.

[0158] As described above, in this embodiment, base station 100 and terminal 200 determine the polarization to be used, for example, in at least a part of the initial access wireless communication (e.g., corresponding to the first phase) and in the wireless communication after the part of the initial access (e.g., corresponding to the second phase).

[0159] For example, terminal 200 can receive signals by a reception method according to the fixed polarization by determining a fixed polarization (for example, a predefined polarization) as the polarization of a channel or signal in initial access (for example, SSB and SIB). Thus, terminal 200 can, for example, suppress the complication of communication processing, reduce the amount of processing, and improve reception performance. Also, for example, terminal 200 can reduce signaling for notifying polarization information by being based on a fixed polarization.

[0160] Furthermore, in this embodiment, for example, terminal 200 sets the polarization notified by base station 100 for a channel or signal used for user data that occupies more time resources or frequency resources compared to initial access.

[0161] Terminal 200 can perform communication processing based on a communication method (e.g., at least one of transmission and reception) corresponding to the polarization set in terminal 200 using a predefined polarization or a polarization notified by base station 100, thereby improving the communication performance of terminal 200.

[0162] Furthermore, by being notified of the polarization, terminal 200 can determine how to use the polarization (for example, either reuse or polarization multiplexing transmission). For example, interference can be avoided by reusing the polarization, and throughput can be improved by polarization multiplexing transmission.

[0163] Therefore, according to this embodiment, terminal 200 can appropriately determine resources (for example, polarization) to be used for communication.

[0164] The fixed polarization may be, for example, specified in advance in a standard, or may be freely set by operation. In the case of setting by operation, terminal 200 may detect the polarization by blind decision at the time of the first connection, and thereafter wait for a signal with the same polarization.

[0165] (Embodiment 2) The configurations of a base station and a terminal according to the present embodiment may be common to the configurations of base station 100 and terminal 200 according to the first embodiment.

[0166] In this embodiment, the polarization set in each cell is associated with identification information of the cell (for example, called a cell ID or a Physical Cell ID (PCI)).

[0167] For example, in an SSB search at the time of initial access, terminal 200 detects the PSS and SSS in the SSB and identifies the cell ID. Then, terminal 200 receives the PBCH in the SSB and acquires system information broadcast in the cell.

[0168] In this embodiment, terminal 200 may set the polarization associated with the cell ID, for example, in the SSB search (or after the SSB search).

[0169] For example, regarding the association between cell IDs and polarization, even cell IDs may be associated with right-handed circular polarization (RHCP) and odd cell IDs may be associated with left-handed circular polarization. In other words, a cell ID whose least significant bit is 0 may be associated with right-handed circular polarization (RHCP), and a cell ID whose least significant bit is 1 may be associated with left-handed circular polarization. Note that the association between even and odd cell IDs and RHCP and LHCP may be reversed.

[0170] Alternatively, for example, cell IDs in a smaller range of numbers (e.g., cell IDs in the first half) may be associated with right-handed circular polarization (RHCP), and cell IDs in a larger range of numbers (e.g., cell IDs in the second half) may be associated with left-handed circular polarization. In other words, for example, a cell ID whose most significant bit is 0 may be associated with right-handed circular polarization (RHCP), and a cell ID whose most significant bit is 1 may be associated with left-handed circular polarization.

[0171] FIG. 18 is a flow diagram showing an example of processing of terminal 200 according to this embodiment.

[0172] For example, when searching for an SSB, terminal 200 performs reception using right-handed circular polarization when detecting a PSS or SSS of a cell ID corresponding to right-handed circular polarization (RHCP) (S401). If a cell ID corresponding to right-handed circular polarization (RHCP) is detected (S402: Yes), terminal 200 sets the polarization to be used for reception processing (in other words, downlink processing) and transmission processing (in other words, uplink processing) to right-handed circular polarization (S405).

[0173] On the other hand, if the PSS or SSS of the cell ID corresponding to the right-handed circular polarization (RHCP) is not detected (S402: No), the terminal 200 performs reception using the left-handed circular polarization in detecting the PSS or SSS of the cell ID corresponding to the left-handed circular polarization (LHCP) (S403). If the cell ID corresponding to the left-handed circular polarization (LHCP) is detected (S404: Yes), the terminal 200 sets the left-handed circular polarization as the polarization to be used for the reception process (in other words, the downlink process) and the transmission process (in other words, the uplink process) (S405).

[0174] For example, if the SSB is not detected (S404: No), the terminal 200 returns to the process of S401 and repeats the search for the SSB.

[0175] Then, terminal 200 receives the SIB based on the polarization set based on the cell ID, for example (S406).

[0176] In this manner, in the present embodiment, terminal 200 can determine the polarization associated with a cell ID by detecting the cell ID in the cell search. Therefore, it is not necessary for base station 100 to notify the polarization information, and therefore it is possible to reduce the signaling overhead of the control information for notifying the polarization information.

[0177] Furthermore, in this embodiment, for example, communication can be performed for SSB based on polarization based on the cell ID, so that interference can be avoided by polarization in more channels.

[0178] In FIG. 18, a case has been described in which terminal 200 performs a PSS or SSS reception process (for example, the process of S401 or S404 in FIG. 18) based on a polarization associated with a cell ID to be searched during an SSB search, but the present invention is not limited to this. For example, terminal 200 may identify a cell ID by an SSB search, and determine a polarization associated with the identified cell ID as a polarization to be used for communication after the detection of the cell ID (for example, after the reception of a PBCH included in an SSB). In this case, for example, a fixed polarization (for example, a polarization defined in advance) may be set for the PSS and SSS, which are channels for identifying the cell ID, as in the first embodiment. Also, since the PBCH is transmitted in the same block as the PSS and SSS, the same polarization as the PSS and SSS may be set for the PBCH.

[0179] (Embodiment 3) The configurations of a base station and a terminal according to the present embodiment may be common to the configurations of base station 100 and terminal 200 according to the first embodiment.

[0180] In this embodiment, the polarization set for each beam is associated with identification information of the SSB corresponding to that beam (also called, for example, an SSB ID or an SSB index).

[0181] For example, in this embodiment, terminal 200 may set the polarization associated with the SSB ID of the detected SSB.

[0182] For example, even-numbered SSB IDs may be associated with right-handed circular polarization (RHCP), and odd-numbered SSB IDs may be associated with left-handed circular polarization (LHCP). In other words, SSB IDs whose least significant bit is 0 may be associated with right-handed circular polarization (RHCP), and SSB IDs whose least significant bit is 1 may be associated with left-handed circular polarization. Note that the association of even-numbered and odd-numbered SSB IDs with RHCPs and LHCPs may be reversed.

[0183] Alternatively, for example, SSB IDs in a smaller range of numbers (e.g., SSB IDs in the first half) may be associated with right-handed circular polarization (RHCP), and SSB IDs in a larger range of numbers (e.g., SSB IDs in the second half) may be associated with left-handed circular polarization. In other words, for example, SSB IDs whose most significant bit is 0 may be associated with right-handed circular polarization (RHCP), and SSB IDs whose most significant bit is 1 may be associated with left-handed circular polarization.

[0184] Here, for example, in NR Rel.15, the most significant bit (MSB) side of the SSB ID is notified by the PBCH DMRS (a reference signal used for PBCH demodulation), and the least significant bit (LSB) side is notified by the data portion of the PBCH. For example, terminal 200 can identify the MSB side of the SSB ID when it detects the PBCH DMRS. On the other hand, terminal 200 cannot identify the LSB of the SSB ID until it decodes and analyzes the data portion of the PBCH.

[0185] Therefore, for example, the polarization notification may be associated with the most significant bit (e.g., MSB) of the SSB ID. This association allows terminal 200 to determine the polarization associated with the SSB ID before decoding the data portion of the PBCH, and therefore allows terminal 200 to receive the data portion of the PBCH based on the cell- or beam-specific polarization.

[0186] FIG. 19 is a flow diagram showing an example of processing of terminal 200 according to this embodiment.

[0187] Terminal 200 searches (in other words, detects) a PSS or SSS included in an SSB, for example (S501). In detecting a PSS or SSS, terminal 200 may search based on a fixed polarization, or may search by switching between no polarization, right-handed circular polarization, and left-handed circular polarization (in other words, blind detection), or may search by polarization diversity reception.

[0188] For example, if the PSS or SSS is not detected (S502: No), the terminal 200 returns to the process of S501 and repeats the search for the PSS or SSS.

[0189] If a PSS or SSS is detected (S502: Yes), terminal 200 detects an SSB ID (or an SSB index) (S503). Terminal 200 may detect the SSB ID (e.g., the most significant bits of the SSB ID) from the PBCH DMRS, or may detect the SSB ID (e.g., the least significant bits of the SSB ID) from the data portion of the PBCH, for example.

[0190] Terminal 200 sets the polarization associated with the detected SSB ID as the polarization to be used for, for example, reception processing (in other words, downlink processing) and transmission processing (in other words, uplink processing) (S504).

[0191] Then, terminal 200 decodes the PBCH data based on the set polarization, for example (S505), and receives the SIB (S506).

[0192] In this manner, in this embodiment, terminal 200 can determine the polarization associated with the SSB ID by detecting the SSB ID. Therefore, it is not necessary for base station 100 to notify the polarization information, and therefore the signaling overhead of the control information for notifying the polarization information can be reduced.

[0193] Furthermore, in this embodiment, for example, communication can be performed based on the polarization based on the SSB ID even for initial access processing after detection of the SSB ID (for example, reception of a PBCH or SIB). For example, when the MSB of the SSB ID is associated with a polarization, terminal 200 can perform communication processing based on the polarization associated with the SSB ID in processing after reception of the data portion of the PBCH. Also, for example, when the LSB of the SSB ID is associated with a polarization, terminal 200 can perform communication processing based on the polarization associated with the SSB ID in processing after reception of the SIB. Thus, according to this embodiment, interference can be avoided by polarization in more channels.

[0194] The embodiments of the present disclosure have been described above.

[0195] There are two types of satellite communication systems: a "regenerative type" in which the base station functions exist on the satellite, and a "transparent type" in which the base station functions exist in a GW on the ground, and the satellite receives signals from the GW, frequency converts and amplifies the signals, and transmits them. An embodiment of the present disclosure is applicable to both the regenerative type and the transparent type.

[0196] Furthermore, in each of the above-described embodiments, a cell may be an area defined by the received power of an SSB or CSI-RS transmitted by a base station (eg, a satellite), or may be an area defined by a geographical location.

[0197] In addition, in each embodiment, an example is described in which the polarization is circularly polarized, but the polarization may be other polarizations such as linear polarization (e.g., at least one of vertical polarization and horizontal polarization) or elliptical polarization.

[0198] Moreover, each embodiment (and each method) may be combined. For example, base station 100 may notify the polarization for each cell based on embodiment 2, and further may notify the polarization for each terminal 200 based on method 3 of embodiment 1. Also, for example, base station 100 may notify the polarization information for downlink data by the TCI state based on method 3, and may notify the polarization information for uplink data by precoding information based on method 3, as a method of notifying the polarization based on embodiment 1. Also, for example, downlink data may be set on a cell-by-cell basis based on embodiment 2, and uplink data may be set by DCI notification based on method 3 of embodiment 1.

[0199] In addition, in each embodiment, terminal 200 may store the polarization information detected by blind judgment or the notified polarization information at the time of initial access, and thereafter, for example, when terminal 200 is powered off or when terminal 200 enters the RRC_IDLE state, terminal 200 may set the polarization to be used for transmission and reception based on the stored polarization information.

[0200] In addition, in each of the above-described embodiments, an NTN environment (e.g., a satellite communication environment) has been described as an example, but the present disclosure is not limited thereto. The present disclosure may be applied to other communication environments (e.g., a LTE and / or NR terrestrial cellular environment).

[0201] In addition, in each of the above-described embodiments, for example, the terminal 200 sets a fixed polarization in a period before receiving a notification of polarization information, and sets a polarization based on the notification in a period after receiving the notification of polarization information, but the present invention is not limited to this. For example, the terminal 200 may apply the polarization notified from the base station 100 to at least one channel or signal after receiving the notification of polarization information. As an example, the terminal 200 may set the polarization notified by the SIB to the communication of user data without setting it to the RACH processing. In this case, the terminal 200 may set a fixed polarization in the RACH processing, for example. Also, for example, the terminal 200 may switch between the fixed polarization and the polarization notified from the base station 100 depending on the type of the channel or signal.

[0202] Furthermore, in each of the above-described embodiments, a case has been described in which polarization (for example, a fixed polarization and a polarization notified from base station 100) is set in terminal 200 in both initial access and processing after initial access, but this is not limiting. For example, in terminal 200, polarization may be applied in at least one of initial access and processing after initial access. As one example, polarization may not be applied in initial access, and polarization may be applied in processing after initial access. As another example, polarization may not be applied in processing before polarization information is notified from base station 100, and polarization may be applied in processing after polarization information is notified from base station 100.

[0203] Also, the polarization information may be notified only by the satellite, base station, or wireless system that uses the polarization. Also, based on the notification of the terminal capability from the terminal, the information may be notified only to terminals that have NTN or satellite communication capability. The terminal capability may be notified from the terminal to the base station by UE capability, UE feature, Subscriber Profile ID, etc.

[0204] In addition, the term "terminal" in each of the above-mentioned embodiments may be replaced with the term "UE." Furthermore, the term "base station" may be replaced with the term "eNodeB," "eNB," "gNodeB," or "gNB."

[0205] In addition, the notation "... part" in the above-mentioned embodiments may be replaced with other notations such as "... circuitry," "... device," "... unit," or "... module."

[0206] The present disclosure can be realized by software, hardware, or software in cooperation with hardware. Each functional block used in the description of the above embodiment may be realized partially or entirely as an LSI, which is an integrated circuit, and each process described in the above embodiment may be controlled partially or entirely by one LSI or a combination of LSIs. The LSI may be composed of individual chips, or may be composed of one chip so as to include some or all of the functional blocks. The LSI may have input and output of data. Depending on the degree of integration, the LSI may be called an IC, a system LSI, a super LSI, or an ultra LSI.

[0207] The method of integration is not limited to LSI, but may be realized by a dedicated circuit, a general-purpose processor, or a dedicated processor. Also, after LSI manufacturing, a programmable FPGA (Field Programmable Gate Array) or a reconfigurable processor that can reconfigure the connections and settings of circuit cells inside the LSI may be used. The present disclosure may be realized as digital processing or analog processing.

[0208] Furthermore, if a new integrated circuit technology that can replace LSI appears due to the progress of semiconductor technology or a derivative technology, it is possible to integrate the functional blocks using that technology. The application of biotechnology is also a possibility.

[0209] The present disclosure may be implemented in any type of apparatus, device, or system having a communication function (collectively referred to as a communication apparatus). The communication apparatus may include a radio transceiver and processing / control circuitry. The radio transceiver may include a receiver and a transmitter, or both as functions. The radio transceiver (transmitter and receiver) may include a radio frequency (RF) module and one or more antennas. The RF module may include an amplifier, an RF modulator / demodulator, or the like. Non-limiting examples of communication devices include telephones (e.g., cell phones, smartphones, etc.), tablets, personal computers (PCs) (e.g., laptops, desktops, notebooks, etc.), cameras (e.g., digital still / video cameras), digital players (e.g., digital audio / video players), wearable devices (e.g., wearable cameras, smart watches, tracking devices, etc.), game consoles, digital book readers, telehealth and telemedicine devices, communication-enabled vehicles or mobile conveyances (e.g., cars, airplanes, boats, etc.), and combinations of the above devices.

[0210] Communications Equipment includes, but is not limited to portable or mobile equipment, non-portable or fixed equipment, devices and systems of any kind, such as smart home devices (appliances, lighting equipment, smart meters or metering devices, control panels, etc.), vending machines and any other "Things" that may exist on an Internet of Things (IoT) network.

[0211] Communications include data communications via cellular systems, wireless LAN systems, communications satellite systems, etc., as well as data communications via combinations of these.

[0212] A communications apparatus also includes devices, such as controllers and sensors, connected or coupled to a communications device that performs the communications functions described in this disclosure, such as controllers and sensors that generate control and data signals used by the communications device to perform the communications functions of the communications apparatus.

[0213] The communication apparatus also includes infrastructure facilities, such as base stations, access points, and any other apparatus, device, or system that communicates with or controls the various apparatuses listed above, but are not limited to these.

[0214] A terminal according to one embodiment of the present disclosure includes a control circuit that determines a polarization to be used in at least one of a first wireless communication and a second wireless communication subsequent to the first wireless communication, and a communication circuit that performs the at least one wireless communication using the determined polarization.

[0215] In one embodiment of the present disclosure, the control circuit determines a predefined polarization as the polarization to be used for the first wireless communication.

[0216] In one embodiment of the present disclosure, the control circuit determines the polarization to be used for the second wireless communication based on information received from a base station.

[0217] In one embodiment of the present disclosure, the information is system information, and the control circuit determines the polarization indicated by the system information as the polarization to be used for the second wireless communication after the system information is received.

[0218] In one embodiment of the present disclosure, the information is higher layer signaling specific to a terminal, and the control circuit determines the polarization indicated by the higher layer signaling as the polarization to be used for the second wireless communication after the higher layer signaling is received.

[0219] In one embodiment of the present disclosure, the information is downlink control information, and the control circuit determines the polarization to be used for the second wireless communication after the downlink control information is received, based on the polarization indicated by the downlink control information.

[0220] In one embodiment of the present disclosure, the polarization indicated by the downlink control information is indicated by downlink transmission setting information or information regarding precoding.

[0221] In one embodiment of the present disclosure, the information is identification information of a cell, and the identification information of the cell is associated with the polarization.

[0222] In one embodiment of the present disclosure, the information is identification information of a synchronization signal corresponding to a beam, and the identification information of the synchronization signal is associated with the polarization.

[0223] In an embodiment of the present disclosure, among a plurality of bits constituting the identification information of the synchronization signal, a bit included in a demodulation reference signal of a broadcast channel is associated with the polarization.

[0224] In a communication method according to one embodiment of the present disclosure, a terminal determines a polarization to be used in at least one of a first wireless communication and a second wireless communication subsequent to the first wireless communication, and performs the at least one wireless communication using the determined polarization.

[0225] The disclosures of the specification, drawings and abstract contained in Japanese Patent Application No. 2019-202108, filed on November 7, 2019, are incorporated herein by reference in their entirety. [Industrial Applicability]

[0226] One aspect of the present disclosure is useful in wireless communication systems. [Explanation of symbols]

[0227] 100 base stations 101,204 Control section 102,205 Data Generation Division 103,206 Transmission data processing unit 104,207 Radio transmitter 105,201 Antennas 106,202 Radio receiver 107,203 Received data processing unit 200 terminals

Claims

1. A receiver that receives polarization information used for downlink reception and / or uplink transmission in wireless communication from a base station, A receiving unit, the polarization information including polarization information of any one of left-handed circular polarization (LHCP), right-handed circular polarization (RHCP), or linear polarization; a communication circuit for performing the wireless communication using a polarization indicated by the received polarization information; Equipped with The receiving unit receives the polarization information including polarization information of a neighboring cell, The communication circuit performs radio measurement of the neighboring cell using the polarization indicated in the received polarization information of the neighboring cell. Terminal.

2. The polarization information is system information, the communication circuit uses a polarization indicated by the system information for the wireless communication; The terminal according to claim 1.

3. The polarization information of the neighboring cells is indicated together with channel state information reference signal (CSI-RS) information, The terminal according to claim 1.

4. The wireless communication includes a first wireless communication and / or a second wireless communication subsequent to the first wireless communication. The terminal according to claim 1.

5. The communication circuit uses a defined polarization for the first wireless communication. The terminal according to claim 4.

6. the communication circuit uses, for the second wireless communication, a polarized wave based on the polarization information received from the base station. The terminal according to claim 4.

7. The polarization information is terminal-specific higher layer signaling, the communication circuit uses the polarization indicated by the higher layer signaling for the second wireless communication after the higher layer signaling is received; The terminal according to claim 6.

8. The polarization information is downlink control information, the communication circuit uses a polarized wave based on a polarization indicated by the downlink control information for the second wireless communication after the downlink control information is received. The terminal according to claim 6.

9. The polarization indicated by the downlink control information is indicated by downlink transmission setting information or information regarding precoding. The terminal according to claim 8.

10. The polarization information is identification information of a cell, The identification information of the cell is associated with the polarization. The terminal according to claim 6.

11. The polarization information is identification information of a synchronization signal corresponding to a beam, The identification information of the synchronization signal is associated with the polarization. The terminal according to claim 6.

12. Among the plurality of bits constituting the identification information of the synchronization signal, a bit included in a demodulation reference signal of a broadcast channel is associated with the polarization. The terminal according to claim 11.

13. The terminal is receiving polarization information used for downlink reception and / or uplink transmission in wireless communication from a base station; The polarization information includes polarization information of either left-handed circular polarization (LHCP), right-handed circular polarization (RHCP), or linear polarization; performing the wireless communication using the polarization indicated by the received polarization information; receiving the polarization information including polarization information of neighboring cells; performing radio measurement of the neighboring cell using the polarization indicated in the received polarization information of the neighboring cell; Communication methods.

14. A transmitter that transmits polarization information used for downlink reception and / or uplink transmission in wireless communication to a terminal, A transmitter, wherein the polarization information includes polarization information of either left-handed circular polarization (LHCP), right-handed circular polarization (RHCP), or linear polarization; a communication circuit for performing the wireless communication using a polarization indicated by the transmitted polarization information; Equipped with The transmitter transmits the polarization information including polarization information of neighboring cells. Base station.

15. The polarization information is transmitted by system information. The base station of claim 14.

16. The polarization information of the neighboring cells is indicated by channel state information reference signal (CSI-RS) information, The base station of claim 14.

17. The base station is Transmitting polarization information used for downlink reception and / or uplink transmission in wireless communication to a terminal; The polarization information includes polarization information of either left-handed circular polarization (LHCP), right-handed circular polarization (RHCP), or linear polarization; performing the wireless communication using the polarization indicated by the transmitted polarization information; Transmitting the polarization information including polarization information of neighboring cells; Communication methods.

18. The integrated circuit that controls the terminal is receiving polarization information used for downlink reception and / or uplink transmission in wireless communication from a base station; The polarization information includes polarization information of either left-handed circular polarization (LHCP), right-handed circular polarization (RHCP), or linear polarization; performing the wireless communication using the polarization indicated by the received polarization information; receiving the polarization information including polarization information of neighboring cells; performing radio measurement of the neighboring cell using the polarization indicated in the received polarization information of the neighboring cell; Integrated circuits.

19. The integrated circuit that controls the base station is Transmitting polarization information used for downlink reception and / or uplink transmission in wireless communication to a terminal; The polarization information includes polarization information of either left-handed circular polarization (LHCP), right-handed circular polarization (RHCP), or linear polarization; performing the wireless communication using the polarization indicated by the transmitted polarization information; Transmitting the polarization information including polarization information of neighboring cells; Integrated circuits.

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