US-12628156-B2 - Terminal and method for controlling repetition of uplink control channel

US12628156B2US 12628156 B2US12628156 B2US 12628156B2US-12628156-B2

Abstract

A terminal transmits an uplink control channel corresponding to an antenna beam transmitted from a radio base station. The terminal assumes a symbol location of a repetition of the uplink control channel based on an explicit or implicit notification.

Inventors

Daisuke KURITA
Hiroki Harada
Shohei Yoshioka

Assignees

NTT DOCOMO, INC.

Dates

Publication Date: 20260512
Application Date: 20200228

Claims (3)

1 . A terminal comprising: a receiver that receives downlink control information; a transmitter that transmits an uplink control channel; and a processor that controls a repetition of the uplink control channel in a short format of the uplink control channel, wherein the processor assumes an interval between each uplink control channel in the repetition, and wherein the processor dynamically configures the number of the repetitions based on the downlink control information.
2 . A radio communication system including a radio base station and a terminal, wherein the radio base station comprises a first transmitter that transmits downlink control information, and the terminal comprises: a receiver that receives the downlink control information; a second transmitter that transmits an uplink control channel; and a processor that controls a repetition of the uplink control channel in a short format of the uplink control channel, wherein the processor assumes an interval between each uplink control channel in the repetition, and wherein the processor dynamically configures the number of the repetitions based on the downlink control information.
3 . A radio communication method in a terminal, comprising: receiving downlink control information; transmitting an uplink control channel; and controlling a repetition of the uplink control channel in a short format of the uplink control channel, wherein in the controlling, assuming an interval between each uplink control channel in the repetition, and wherein in the controlling, dynamically configuring the number of the repetitions based on the downlink control information.

Description

TECHNICAL FIELD The present disclosure relates to a terminal that performs radio communication, and particularly to a terminal that transmits an uplink control channel. BACKGROUND ART The 3rd Generation Partnership Project (3GPP) specifies the 5th generation mobile communication system (5G, also called New Radio (NR) or Next Generation (NG)), and the next generation called Beyond 5G or 6G has been also specified. In Release 17 of 3GPP, Coverage Enhancement (CE) of NR is agreed as a study item (SI) (Non Patent Literature 1). In the SI, an uplink data channel (PUSCH: Physical Uplink Shared Channel) and an uplink control channel (PUCCH: Physical Uplink Control Channel) are listed as performance improvement target channels. As a general method for implementation of CE, known is a repetition of transmission of the channel in a time direction. CITATION LIST Non Patent Literature Non Patent Literature 1: “New SID on NR coverage enhancement”, RP-193240, 3GPP TSG RAN Meeting #86, 3GPP, December 2019 SUMMARY OF INVENTION However, there are the following problems in the case of implementing CE of NR. In Release 15 and Release 16 (NR) of 3GPP, a radio base station (gNB) can sequentially transmit a plurality of antenna beams having different radiation directions while performing switching in a time domain. However, when the plurality of antenna beams are switched in the time domain, the compatibility with the PUCCH repetition specified in NR is Poor. There are restrictions on the repetition configuration when the PUCCH repetition is combined for the plurality of antenna beams, and thus, it is difficult to design efficient resource allocation of the PUCCH repetition. Therefore, the following disclosure has been made in view of such a situation, and aims to provide a terminal that can implement a more efficient repetition of an uplink control channel when a plurality of antenna beams from a radio base station are used. One aspect of the present disclosure is a terminal (UE 200) including: a transmitting unit (control signal/reference signal processing unit 240) that transmits an uplink control channel corresponding to an antenna beam (beam BM) transmitted from a radio base station (gNB 100); and a control unit (control unit 270) that controls a repetition of the uplink control channel, the control unit assuming a symbol location of the repetition based on an explicit or implicit notification. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is an overall schematic configuration diagram of a radio communication system 10. FIG. 2 is a view illustrating a frequency range used in the radio communication system 10. FIG. 3 is a view illustrating a configuration example of a radio frame, a subframe, and a slot used in a radio communication system 10. FIG. 4 is a functional block configuration diagram of an UE 200. FIG. 5 is a view illustrating an example of a PUCCH repetition according to Release-15 and Release-16 of 3GPP. FIG. 6 is a view illustrating a configuration example (Part 1) of repetition mapping to a plurality of antenna beams according to Operation Example 1. FIG. 7 is a view illustrating a configuration example (Part 2) of the repetition mapping to the plurality of antenna beams according to Operation Example 1. FIG. 8 is a view illustrating a configuration example (Part 3) of the repetition mapping to the plurality of antenna beams according to Operation Example 1. FIG. 9 is a view illustrating an example of specifying a start symbol of a repetition and a slot difference between repetitions according to Operation Example 1. FIG. 10 is a view illustrating a configuration example of PUCCH-Config according to Operation Example 1. FIG. 11 is a view illustrating that the UE 200 according to Operation Example 1 assumes a mapping location of a repetition with reference to the number of beams BM. FIG. 12 is a view illustrating an example of a relationship between an antenna beam and a PUCCH repetition according to Operation Example 2. FIG. 13 is a view illustrating a dynamic notification example of a PUCCH repetition using DCI format 1_0 or 1_1 according to Operation Example 3. FIG. 14 is a view illustrating a dynamic notification example of a PUCCH repetition using MAC-CE according to Operation Example 3. FIG. 15 is a diagram illustrating an example of a hardware configuration of the UE 200. DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment will be described with reference to the drawings. Note that the same functions and configurations are denoted by the same or similar reference signs, and the description thereof will be omitted as appropriate. (1) Overall Schematic Configuration of Radio Communication System FIG. 1 is an overall schematic configuration diagram of a radio communication system 10 according to the present embodiment. The radio communication system 10 is a radio communication system according to 5G New Radio (NR), and includes: a next generation-radio access network 20 (hereinafter, NG-RAN 20; and a terminal 200 (