# US 2021/0344404 A1 · User terminal and base station

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2021/0344404 A1
- Document ID: US20210344404A1
- Status: Published application
- Kind: A1
- Application number: 17/261,315
- Filed: 2018-07-20
- Published: 2021-11-04
- Earliest claimed: 2018-07-20
- Assignees: Ntt Docomo, Inc.
- Applicants: Ntt Docomo, Inc.
- Inventors: Yuki Matsumura; Kazuki Takeda; Satoshi Nagata
- Web page: https://patentgrep.com/patent/US20210344404A1

## CPC

- H04B 7/088: {using beam selection}
- H04B 7/06964: {Re-selection of one or more beams after beam failure}
- H04B 7/0882: {using post-detection diversity}
- H04L 5/0053: {Allocation of signalling, i.e. of overhead other than pilot signals}
- H04W 16/28: using beam steering
- H04W 76/19: Connection re-establishment
- H04L 5/001: {the frequencies being arranged in component carriers}
- H04L 5/0051: {of dedicated pilots, i.e. pilots destined for a single user or terminal}
- H04L 27/26025: {Numerology, i.e. varying one or more of symbol duration, subcarrier spacing, Fourier transform size, sampling rate or down-clocking (allocating sub-channels of the transmission path H04L5/003)}
- H04L 27/26136: {Pilot sequence conveying additional information}
- H04B: TRANSMISSION
- 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

A user terminal includes a transmitting section that transmits a beam recovery request and a control section that uses at least one of an uplink control channel, an uplink shared channel, and a demodulation reference signal, for transmission of the beam recovery request. According to one aspect of the present disclosure, it is possible to improve performance in a beam recovery.

## Claims

### Claim 1

A user terminal comprising:
a transmitting section that transmits a beam recovery request; and
a control section that uses at least one of an uplink control channel, an uplink shared channel, and a demodulation reference signal, for transmission of the beam recovery request.

### Claim 2 (depends on 1)

The user terminal according to claim 1, wherein the control section uses a time resource based on a measurement result of a plurality of measurement signals among a plurality of time resources respectively associated with the plurality of measurement signals, for the uplink control channel or the uplink shared channel.

### Claim 3 (depends on 1)

The user terminal according to claim 1, wherein the control section uses a sequence depending on presence or absence of beam failure, in the demodulation reference signal.

### Claim 4 (depends on 1)

The user terminal according to claim 1, wherein the control section uses subcarrier spacing different from subcarrier spacing used for measurement, for the beam recovery request.

### Claim 5 (depends on 1)

The user terminal according to claim 1, wherein the control section uses a random access preamble for the beam recovery request in a case of detecting a beam failure in a primary cell or a primary secondary cell.

### Claim 6

A base station comprising:
a receiving section that receives a beam recovery request; and
a control section that uses at least one of an uplink control channel, an uplink shared channel, and a demodulation reference signal, for reception of the beam recovery request.

### Claim 7 (depends on 2)

The user terminal according to claim 2, wherein the control section uses a sequence depending on presence or absence of beam failure, in the demodulation reference signal.

### Claim 8 (depends on 2)

The user terminal according to claim 2, wherein the control section uses subcarrier spacing different from subcarrier spacing used for measurement, for the beam recovery request.

### Claim 9 (depends on 3)

The user terminal according to claim 3, wherein the control section uses subcarrier spacing different from subcarrier spacing used for measurement, for the beam recovery request.

### Claim 10 (depends on 2)

The user terminal according to claim 2, wherein the control section uses a random access preamble for the beam recovery request in a case of detecting a beam failure in a primary cell or a primary secondary cell.

### Claim 11 (depends on 3)

The user terminal according to claim 3, wherein the control section uses a random access preamble for the beam recovery request in a case of detecting a beam failure in a primary cell or a primary secondary cell.

### Claim 12 (depends on 4)

The user terminal according to claim 4, wherein the control section uses a random access preamble for the beam recovery request in a case of detecting a beam failure in a primary cell or a primary secondary cell.