# US 12,120,745 B2 · User terminal

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- Number: US 12,120,745 B2
- Document ID: US12120745B2
- Status: Granted
- Kind: B2
- Application number: 17/430,916
- Filed: 2019-02-15
- Published: 2022-04-28
- Granted: 2024-10-15
- Earliest claimed: 2019-02-15
- Assignees: Ntt Docomo, Inc.
- Applicants: Ntt Docomo, Inc.
- Inventors: Kazuki Takeda; Satoshi Nagata; Lihui Wang
- Web page: https://patentgrep.com/patent/US12120745B2

## CPC

- H04W 8/26: Network addressing or numbering for mobility support
- H04W 74/0833: Random access procedures, e.g. with 4-step access
- H04W 74/04: Scheduled access (hybrid access H04W74/02)
- H04W 74/0836: with 2-step access
- H04W 74/0838: using contention-free random access [CFRA]
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)

## Abstract

To appropriately perform communications even when a random access procedure with less steps than existing steps is performed, an aspect of a user terminal according to the present disclosure includes a transmitting section that transmits a UL signal including a random access preamble and a certain message, a receiving section that receives a DL signal transmitted in response to the UL signal, and a control section that controls at least one of transmission of the UL signal and reception of the DL signal by applying a common behavior to a first procedure for transmitting the UL signal in accordance with an indication from a network and a second procedure for transmitting the UL signal without any indication from the network.

## Claims

### Claim 1

A terminal comprising:
a processor that determines, based on higher layer signaling indicating transmission of message A including a random access preamble, whether or not to apply a 2-step contention-free random access procedure;
a transmitter that, when the 2-step contention-free random access procedure is applied, transmits the message A; and
a receiver that receives, as a response to the message A, message B including a downlink control channel received in a common search space set,
wherein cyclic redundancy check (CRC) of downlink control information on the downlink control channel is scrambled by an identifier included in the message A.

### Claim 2 (depends on 1)

The terminal according to claim 1, wherein when the 2-step contention-free random access procedure is applied, the transmitter transmits the message A by using a resource corresponding to a synchronization signal block.

### Claim 3

A radio communication method for a terminal, comprising:
determining, based on higher layer signaling indicating transmission of message A including a random access preamble, whether or not to apply a 2-step contention-free random access procedure;
when the 2-step contention-free random access procedure is applied, transmitting the message A; and
receiving, as a response to the message A, message B including a downlink control channel received in a common search space set,
wherein cyclic redundancy check (CRC) of downlink control information on the downlink control channel is scrambled by an identifier included in the message A.

### Claim 4

A base station comprising:
a processor that indicates, by using higher layer signaling indicating transmission of message A including a random access preamble, whether or not to apply a 2-step contention-free random access procedure;
a receiver that, when the 2-step contention-free random access procedure is applied, receives the message A; and
a transmitter that transmits, as a response to the message A, message B including a downlink control channel received in a common search space set,
wherein cyclic redundancy check (CRC) of downlink control information on the downlink control channel is scrambled by an identifier included in the message A.

### Claim 5

A system comprising a terminal and a base station, wherein
the terminal comprises:
a processor that determines, based on higher layer signaling indicating transmission of message A including a random access preamble, whether or not to apply a 2-step contention-free random access procedure;
a transmitter that, when the 2-step contention-free random access procedure is applied, transmits the message A; and
a receiver that receives, as a response to the message A, message B including a downlink control channel received in a common search space set,
wherein cyclic redundancy check (CRC) of downlink control information on the downlink control channel is scrambled by an identifier included in the message A, and
the base station comprises:
a receiver that receives the message A; and
a transmitter that transmits the message B.