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US-20260128753-A1 - TERMINAL AND COMMUNICATION METHOD

US20260128753A1US 20260128753 A1US20260128753 A1US 20260128753A1US-20260128753-A1

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.

Inventors

  • Akihiko Nishio
  • Hidetoshi Suzuki

Assignees

  • PANASONIC INTELLECTUAL PROPERTY CORPORATION OF AMERICA

Dates

Publication Date
20260507
Application Date
20260105
Priority Date
20191107

Claims (11)

  1. 1 . A terminal, comprising: a receiver, which, in operation, receives, from a base station, polarization information used for Non-Terrestrial Network (NTN) radio communication, and receives, from the base station, a handover message, the polarization information indicating polarization selected from a set including left handed circular polarization (LHCP), right handed circular polarization (RHCP), and linear polarization; and communication circuitry, which, in operation, performs the NTN radio communication by using the polarization indicated in the polarization information, wherein the NTN radio communication comprises first NTN radio communication and second NTN radio communication that is after the first NTN radio communication, the communication circuitry, in operation, uses, in the first NTN radio communication, defined polarization, and the communication circuitry, in operation, uses the polarization in the second NTN radio communication indicated in the polarization information by the first NTN radio communication.
  2. 2 . The terminal according to claim 1 , wherein: the polarization information is system information; and the communication circuitry, in operation, uses the polarization indicated by the system information.
  3. 3 . The terminal according to claim 1 , wherein: the receiver, in operation, receives the polarization information which includes polarization information of a neighboring cell; and the communication circuitry, in operation, performs a radio measurement of the neighboring cell by using polarization indicated in the received polarization information of the neighboring cell.
  4. 4 . The terminal according to claim 3 , wherein: the polarization information of the neighboring cell is signaled with channel state information reference signal (CSI-RS) information.
  5. 5 . The terminal according to claim 1 , wherein: the polarization information is a terminal-dedicated higher layer signaling; and the communication circuitry, in operation, uses the polarization indicated by the terminal-dedicated higher layer signaling in the NTN radio communication after reception of the terminal-dedicated higher layer signaling.
  6. 6 . The terminal according to claim 1 , wherein: the polarization information is downlink control information; and the communication circuitry, in operation, uses the polarization indicated by the downlink control information in the NTN radio communication after reception of the downlink control information.
  7. 7 . The terminal according to claim 6 , wherein: the downlink control information which indicates the polarization is downlink transmission configuration information or information on precoding.
  8. 8 . The terminal according to claim 1 , wherein: the polarization information is identification information of a cell; and the identification information of the cell and the polarization are associated with each other.
  9. 9 . The terminal according to claim 1 , wherein: the polarization information is identification information of a synchronization signal corresponding to a beam; and the identification information of the synchronization signal and the polarization are associated with each other.
  10. 10 . The terminal according to claim 9 , wherein: the polarization is associated with a bit included in a reference signal for demodulating a broadcast channel, among a plurality of bits constituting the identification information of the synchronization signal.
  11. 11 . A communication method performed by a terminal, the communication method comprising: receiving, from a base station, polarization information used for of Non-Terrestrial Network (NTN) radio communication, the polarization information indicating polarization selected from a set including left handed circular polarization (LHCP), right handed circular polarization (RHCP), and linear polarization; receiving, from the base station, a handover message; and performing the NTN radio communication by using the polarization indicated in the polarization information, wherein the NTN radio communication comprises first NTN radio communication and second NTN radio communication that is after the first NTN radio communication, the terminal uses, in the first NTN radio communication, defined polarization, and the terminal uses the polarization in the second NTN radio communication indicated in the polarization information by the first NTN radio communication.

Description

TECHNICAL FIELD The present disclosure relates to a terminal and a communication method. BACKGROUND ART In the standardization of 5G, New Radio access technology (NR) was discussed in 3GPP and the Release 15 (Rel. 15) specification for NR has been published. CITATION LIST Non-Patent Literature NPL 1 3GPP, TR38.811 V15.2.0, “Study on New Radio (NR) to support non terrestrial networks (Release 15),” 2019-09 NPL 2 3GPP TSG RAN WG1 #98bis, R1-1911003, “On physical layer control procedures for NTN,” October, 2019 SUMMARY OF INVENTION Technical Problem However, there is scope for further study on a method for determining polarization used for radio communication in radio communication systems. One non-limiting and exemplary embodiment facilitates providing a terminal and a communication method each capable of determining polarization used for radio communication. A terminal according to an exemplary embodiment of the present disclosure includes: control circuitry, which, in operation, determines polarization to be used in at least one of first radio communication and/or second radio communication which is after the first radio communication; and communication circuitry, which, in operation, performs the at least one of the first radio communication and/or the second radio communication by using the determined polarization. Note that these generic or specific aspects may be achieved by a system, an apparatus, a method, an integrated circuit, a computer program, or a recoding medium, and also by any combination of the system, the apparatus, the method, the integrated circuit, the computer program, and the recoding medium. According to an exemplary embodiment of the present disclosure, it is possible to determine polarization used for radio communication. Additional benefits and advantages of the disclosed exemplary embodiments will become apparent from the specification and drawings. The benefits and/or advantages may be individually obtained by the various embodiments and features of the specification and drawings, which need not all be provided in order to obtain one or more of such benefits and/or advantages. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 illustrates an exemplary architecture of a 3GPP NR system; FIG. 2 schematically illustrates a functional split between Next Generation-Radio Access Network (NG-RAN) and 5th Generation Core (5GC); FIG. 3 is a sequence diagram of a Radio Resource Control (RRC) connection setup/reconfiguration procedure; FIG. 4 schematically illustrates usage scenarios of enhanced Mobile BroadBand (eMBB), massive Machine Type Communications (mMTC), and Ultra Reliable and Low Latency Communications (URLLC); FIG. 5 is a block diagram illustrating an exemplary 5G system architecture for a non-roaming scenario; FIG. 6 illustrates exemplary reusing methods for resources; FIG. 7 is a block diagram illustrating a configuration of a part of a base station according to Embodiment 1; FIG. 8 is a block diagram illustrating a configuration of a part of a terminal according to Embodiment 1; FIG. 9 is a block diagram illustrating a configuration example of the base station according to Embodiment 1; FIG. 10 is a block diagram illustrating a configuration example of the terminal according to Embodiment 1; FIG. 11 illustrates an exemplary initial access; FIG. 12 is a flowchart illustrating an operation example of a terminal according to Method 1 in Embodiment 1; FIG. 13 is a flowchart illustrating an operation example of a terminal according to Method 2 in Embodiment 1; FIG. 14 is a flowchart illustrating an operation example of a terminal according to Method 3 in Embodiment 1; FIG. 15 illustrates exemplary quasi co-location (QCL) Types; FIG. 16 illustrates an exemplary radio resource control (RRC) message on a TCI state and the QCL; FIG. 17 illustrates an example of Precoding information; FIG. 18 is a flowchart illustrating an operation example of a terminal according to Embodiment 2; and FIG. 19 is a flowchart illustrating an operation example of a terminal according to Embodiment 3. DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. 5G NR System Architecture and Protocol Stack 3GPP has been working on the next release for the 5th generation cellular technology (simply called “5G”), including the development of a new radio access technology (NR) operating in frequencies ranging up to 100 GHz. The first version of the 5G standard was completed at the end of 2017, which allows proceeding to 5G NR standard-compliant trials and commercial deployments of terminals (e.g., smartphones). For example, the overall system architecture assumes an NG-RAN (Next Generation-Radio Access Network) that includes gNBs, providing the NG-radio access user plane (SDAP/PDCP/RLC/MAC/PHY) and control plane (RRC) protocol terminations towards the UE. The gNBs are interconnected with each other by means of the Xn interface. The gNBs