# US 2019/0174485 A1 · User terminal and radio communication method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0174485 A1 - Document ID: US20190174485A1 - Status: Published application - Kind: A1 - Application number: 16/322,154 - Filed: 2017-08-02 - Published: 2019-06-06 - Earliest claimed: 2016-08-03 - Assignees: Ntt Docomo, Inc. - Applicants: Ntt Docomo, Inc. - Inventors: Ryosuke OSAWA; Hiroki HARADA; Yuichi KAKISHIMA - Web page: https://patentgrep.com/patent/US20190174485A1 ## CPC - H04B 7/0617: {for beam forming} - H04W 72/21: in the uplink direction of a wireless link, i.e. towards the network - H04L 5/0048: {Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091)} - H04W 8/22: Processing or transfer of terminal data, e.g. status or physical capabilities - H04W 16/28: using beam steering - H04W 72/046: {the resource being in the space domain, e.g. beams} - H04W 88/02: Terminal devices - H04B 7/0404: the mobile station comprising multiple antennas, e.g. to provide uplink diversity - H04L 5/0023: {Time-frequency-space} - H04B: TRANSMISSION - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract The present invention is designed to suitably reduce the decrease of throughput when communication is carried out using beamforming. A user terminal, according to one aspect of the present invention, has a control section that controls formation of a beam for use in transmitting an uplink signal, and a transmission section that transmits information about a characteristic of a transmitter/receiver, and, after the information about the characteristic of the transmitter/receiver is transmitted, the control section determines whether the beam is formed based on downlink channel information or uplink channel information. ## Claims ### Claim 1 A user terminal comprising: a control section that controls formation of a beam for use in transmitting an uplink signal; and a transmission section that transmits information about a characteristic of a transmitter/receiver, wherein, after the information about the characteristic of the transmitter/receiver is transmitted, the control section determines whether the beam is formed based on downlink channel information or uplink channel information. ### Claim 2 (depends on 1) The user terminal according to claim 1, wherein, when the uplink channel information is received after transmitting the information about the characteristic of the transmitter/receiver, the control section exerts control so as to form the beam based on the uplink channel information received. ### Claim 3 (depends on 2) The user terminal according to claim 2, wherein the transmission section transmits an uplink reference signal for uplink channel estimation based on an uplink reference signal transmission indication that is transmitted in response to reception of the information about the characteristic of the transmitter/receiver. ### Claim 4 (depends on 1) The user terminal according to claim 1, wherein, when the uplink channel information and/or an uplink reference signal transmission indication is not received after the information about the characteristic of the transmitter/receiver is transmitted, the control section exerts control so as to form the beam based on the downlink channel information. ### Claim 5 (depends on 1) The user terminal according to claim 1, wherein the information about the characteristic of the transmitter/receiver is information that represents a degree of difference in frequency characteristics between the transmitter and the receiver of the user terminal. ### Claim 6 A radio communication method comprising: controlling formation of a beam for use in transmitting an uplink signal; and transmitting information about a characteristic of a transmitter/receiver, wherein, after information about the characteristic of the transmitter/receiver is transmitted, whether the beam is formed based on downlink channel information or uplink channel information is determined. ### Claim 7 (depends on 2) The user terminal according to claim 2, wherein, when the uplink channel information and/or an uplink reference signal transmission indication is not received after the information about the characteristic of the transmitter/receiver is transmitted, the control section exerts control so as to form the beam based on the downlink channel information. ### Claim 8 (depends on 3) The user terminal according to claim 3, wherein, when the uplink channel information and/or an uplink reference signal transmission indication is not received after the information about the characteristic of the transmitter/receiver is transmitted, the control section exerts control so as to form the beam based on the downlink channel information. ### Claim 9 (depends on 2) The user terminal according to claim 2, wherein the information about the characteristic of the transmitter/receiver is information that represents a degree of difference in frequency characteristics between the transmitter and the receiver of the user terminal. ### Claim 10 (depends on 3) The user terminal according to claim 3, wherein the information about the characteristic of the transmitter/receiver is information that represents a degree of difference in frequency characteristics between the transmitter and the receiver of the user terminal. ### Claim 11 (depends on 4) The user terminal according to claim 4, wherein the information about the characteristic of the transmitter/receiver is information that represents a degree of difference in frequency characteristics between the transmitter and the receiver of the user terminal.