User terminal, radio base station, and radio communication method

• US 10,455,579 B2
• Filed: 09/25/2015
• Issued: 10/22/2019
• Est. Priority Date: 09/25/2014
• Status: Active Grant

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Takeda, Kazuaki, Yasukawa, Shimpei, Nagata, Satoshi
• Primary Examiner(s): Liu, Jung
• Application Number:
  US15/514,036
• Publication Number:
  US 20170290017A1
• Time in Patent Office: 1,488 Days
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 74/08 Non-scheduled access, e.g. ALOHA hybrid access H04W74/02
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

According to the present invention, in an LTE system, communication can appropriately carried out even in the case where a bandwidth utilized in the transmission/receiving of data signals and control signals is configured narrower than the system bandwidth. According to an embodiment, a user terminal is configured to carry out communication with a radio base station using a narrow bandwidth that is limited to a narrower bandwidth than a system bandwidth. The user terminal includes a decision section configured to decide a frequency position for the narrow bandwidth to be arranged, based on given information; and a receiving section configured to receive a control signal and a data signal that are allocated on the narrow bandwidth based on the frequency position. The narrow bandwidth is arranged at different frequency positions per a predetermined period of time.

Claims

1. A user terminal communicating with use of a narrow bandwidth that is limited to a part of a system band, the user terminal comprising:

a decision section that decides a frequency position for the narrow bandwidth; and

a receiving section that receives a downlink signal allocated to the narrow bandwidth based on the frequency position,

wherein the receiving section uses symbols included in first to third symbols of a subframe to tune to the frequency position without reading the Physical Downlink Control Channel (PDCCH) in the first to third symbols.

2. The user terminal according to claim 1, wherein

the decision section decides a frequency position of a downlink control channel that is frequency-division-multiplexed with a Physical Downlink Shared Channel (PDSCH), and

the receiving section monitors the downlink control channel in a common search space that is common to a plurality of user terminals.

3. The user terminal according to claim 2, wherein

the receiving section monitors the downlink control channel in the common search space and a user terminal-specific search space that varies among user terminals, and

the common search space and the user terminal-specific search space are allocated to different subframes.

4. The user terminal according to claim 2, wherein the decision section decides a subframe to which the common search space is allocated, on the basis of information provided from a radio base station.

5. A radio communication method for a user terminal communicating with use of a narrow bandwidth that is limited to a part of a system band, the radio communication method comprising:

deciding a frequency position for the narrow bandwidth; and

receiving a downlink signal allocated to the narrow bandwidth based on the frequency position,

wherein the user terminal uses symbols included in first to third symbols of a subframe to tune to the frequency position without reading the Physical Downlink Control Channel (PDCCH) in the first to third symbols.