# US 2019/0356378 A1 · User terminal and radio communication method

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- Number: US 2019/0356378 A1
- Document ID: US20190356378A1
- Status: Published application
- Kind: A1
- Application number: 16/475,780
- Filed: 2018-01-05
- Published: 2019-11-21
- Earliest claimed: 2017-01-06
- Assignees: Ntt Docomo, Inc.
- Applicants: Ntt Docomo, Inc.
- Inventors: Kazuaki Takeda; Satoshi Nagata; Chongning Na; Min Liu; Huiling Jiang; Yuichi Kakishima
- Web page: https://patentgrep.com/patent/US20190356378A1

## CPC

- H04B 7/088: {using beam selection}
- H01Q 3/24: varying the orientation by switching energy from one active radiating element to another, e.g. for beam switching
- H01Q 25/00: Antennas or antenna systems providing at least two radiating patterns (arrangements for changing or varying the orientation or the shape of the directional pattern H01Q3/00)
- H04B 7/0626: {Channel coefficients, e.g. channel state information [CSI]}
- H04B 7/06952: {Selecting one or more beams from a plurality of beams, e.g. beam training, management or sweeping}
- H04L 5/0051: {of dedicated pilots, i.e. pilots destined for a single user or terminal}
- H04L 5/10: with dynamo-electric generation of carriers; with mechanical filters or demodulators
- H04W 16/28: using beam steering
- H04W 24/10: Scheduling measurement reports {; Arrangements for measurement reports}
- H04W 88/02: Terminal devices
- H04B: TRANSMISSION
- H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72)
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)

## Abstract

The invention is designed to switch beams quickly. A user terminal, according to the present invention, has a receiving section that receives a downlink (DL) signal, and a control section that controls a beam to use to transmit and/or receive the DL signal. When the DL signal is transmitted and/or received using one or more candidate beams, the control section selects the beam based on the measurement results of the demodulation reference signals of one or more antenna ports that respectively correspond to the one or more candidate beams.

## Claims

### Claim 1

A user terminal comprising:
a receiving section that receives a DL signal, and
a control section that controls a beam to use to transmit and/or receive the DL signal,
wherein, when the DL signal is transmitted and/or received using one or more candidate beams, the control section selects a beam based on measurement results of demodulation reference signals of one or more antenna ports that respectively correspond to the one or more candidate beams.

### Claim 2 (depends on 1)

The user terminal according to claim 1, wherein, when the DL signal is transmitted and/or received using different candidate beams, different frequency resources in the same slot are allocated.

### Claim 3 (depends on 1)

The user terminal according to claim 1, wherein:
the receiving section receives transmission mode information, which indicates that the DL signal is transmitted and/or received using the one or more candidate beams; and
the control section controls measurements of the demodulation reference signals of the one or more antenna ports based on the transmission mode information.

### Claim 4 (depends on 1)

The user terminal according to claim 1, wherein:
the receiving section receives pattern information that indicates an arrangement pattern of the demodulation reference signals of the one or more antenna ports; and
the control section controls the measurements of the demodulation reference signals of the one or more antenna ports based on the pattern information.

### Claim 5 (depends on 1)

The user terminal according to claim 1, further comprising a transmission section that transmits channel state information, which includes at least one of an index of the selected beam, an indicator of an antenna port corresponding to the selected beam, and the received power of a demodulation reference signal of the antenna port corresponding to the selected beam.

### Claim 6

A radio communication method comprising, in a user terminal, the steps of:
receiving a downlink (DL) signal; and
controlling a beam to use to transmit and/or receive the DL signal,
wherein, when the DL signal is transmitted and/or received using one or more candidate beams, the user terminal selects the beam based on measurement results of demodulation reference signals of one or more antenna ports that respectively correspond to the one or more candidate beams.

### Claim 7 (depends on 2)

The user terminal according to claim 2, wherein:
the receiving section receives transmission mode information, which indicates that the DL signal is transmitted and/or received using the one or more candidate beams; and
the control section controls measurements of the demodulation reference signals of the one or more antenna ports based on the transmission mode information.

### Claim 8 (depends on 2)

The user terminal according to claim 2, wherein:
the receiving section receives pattern information that indicates an arrangement pattern of the demodulation reference signals of the one or more antenna ports; and
the control section controls the measurements of the demodulation reference signals of the one or more antenna ports based on the pattern information.

### Claim 9 (depends on 3)

The user terminal according to claim 3, wherein:
the receiving section receives pattern information that indicates an arrangement pattern of the demodulation reference signals of the one or more antenna ports; and
the control section controls the measurements of the demodulation reference signals of the one or more antenna ports based on the pattern information.

### Claim 10 (depends on 2)

The user terminal according to claim 2, further comprising a transmission section that transmits channel state information, which includes at least one of an index of the selected beam, an indicator of an antenna port corresponding to the selected beam, and the received power of a demodulation reference signal of the antenna port corresponding to the selected beam.

### Claim 11 (depends on 3)

The user terminal according to claim 3, further comprising a transmission section that transmits channel state information, which includes at least one of an index of the selected beam, an indicator of an antenna port corresponding to the selected beam, and the received power of a demodulation reference signal of the antenna port corresponding to the selected beam.

### Claim 12 (depends on 4)

The user terminal according to claim 4, further comprising a transmission section that transmits channel state information, which includes at least one of an index of the selected beam, an indicator of an antenna port corresponding to the selected beam, and the received power of a demodulation reference signal of the antenna port corresponding to the selected beam.