# US 11,122,628 B2 · User equipment apparatus, base station, and random access method

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- Number: US 11,122,628 B2
- Document ID: US11122628B2
- Status: Granted
- Kind: B2
- Application number: 16/474,744
- Filed: 2017-12-14
- Published: 2019-10-17
- Granted: 2021-09-14
- Earliest claimed: 2017-01-06
- Assignees: Ntt Docomo, Inc.
- Applicants: Ntt Docomo, Inc.
- Inventors: Tomoya Ohara; Hiroki Harada
- Web page: https://patentgrep.com/patent/US11122628B2

## CPC

- H04W 52/36: with a discrete range or set of values, e.g. step size, ramping or offsets
- H04W 52/48: during retransmission after error or non-acknowledgment
- H04B 7/088: {using beam selection}
- H04L 1/08: by repeating transmission, e.g. Verdan system {(H04L1/1858 and H04L1/189 take precedence)}
- H04L 1/1819: {with retransmission of additional or different redundancy}
- H04W 16/28: using beam steering
- H04W 52/50: at the moment of starting communication in a multiple access environment
- H04W 72/046: {the resource being in the space domain, e.g. beams}
- H04W 72/30: Resource management for broadcast services
- H04W 74/0833: Random access procedures, e.g. with 4-step access
- H04W 88/02: Terminal devices
- H04W 52/146: {Uplink power control}
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)
- H04B: TRANSMISSION
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)

## Abstract

In one aspect of the present invention, a user equipment apparatus includes a reception unit configured to receive, from a base station, control information indicating a pattern of retransmission schemes to be applied depending on a retransmission count, for retransmitting a preamble through random access to the base station, the retransmission schemes including beam switching and power ramping; and a transmission unit configured to transmit the preamble according to the control information at timing of retransmitting the preamble.

## Claims

### Claim 1

A terminal, comprising:
a reception unit configured to receive, from a base station, control information indicating a pattern of retransmission schemes to be applied depending on a retransmission count, for retransmitting a preamble through random access to the base station, the retransmission schemes including beam switching and power ramping; and
a transmission unit configured to transmit the preamble according to the control information at timing of retransmitting the preamble,
wherein a retransmission scheme used to retransmit the preamble is selected from the retransmission schemes including the beam switching and the power ramping according to an increase in the retransmission count.

### Claim 2 (depends on 1)

The terminal as claimed in claim 1, wherein
the transmission unit transmits a terminal aspect to the base station, and
the reception unit receives the control information indicating the pattern of retransmission schemes which is determined based on the terminal aspect.

### Claim 3 (depends on 1)

The terminal as claimed in claim 1, wherein
the reception unit receives information about a maximum retransmission count of the preamble from the base station.

### Claim 4

A base station, comprising:
a transmission unit configured to transmit, to a terminal, control information indicating a pattern of retransmission schemes to be applied depending on a retransmission count, for the terminal to retransmit a preamble through random access, the retransmission schemes including beam switching and power ramping; and
a reception unit configured to receive the preamble transmitted according to the control information,
wherein a retransmission scheme used to retransmit the preamble is selected from the retransmission schemes including the beam switching and the power ramping according to an increase in the retransmission count.

### Claim 5

A random access method in a terminal, comprising the steps of:
receiving, from a base station, control information indicating a pattern of retransmission schemes to be applied depending on a retransmission count, for retransmitting a preamble through random access to the base station, the retransmission schemes including beam switching and power ramping; and
transmitting the preamble according to the control information at timing of retransmitting the preamble,
wherein a retransmission scheme used to retransmit the preamble is selected from the retransmission schemes including the beam switching and the power ramping according to an increase in the retransmission count.

### Claim 6

A random access method in a base station, comprising:
transmitting, to a terminal, control information indicating a pattern of retransmission schemes to be applied depending on a retransmission count, for the terminal to retransmit a preamble through random access, the retransmission schemes including beam switching and power ramping; and
receiving the preamble transmitted according to the control information,
wherein a retransmission scheme used to retransmit the preamble is selected from the retransmission schemes including the beam switching and the power ramping according to an increase in the retransmission count.

### Claim 7 (depends on 2)

The terminal as claimed in claim 2, wherein
the reception unit receives information about a maximum retransmission count of the preamble from the base station.