USER TERMINAL, RADIO BASE STATION, AND RADIO COMMUNICATION METHOD

• US 20170290017A1
• Filed: 09/25/2015
• Published: 10/05/2017
• 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
• Granted Patent: US 10,455,579 B2
• Time in Patent Office: 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 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 comprising:

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,

wherein the narrow bandwidth is arranged at different frequency positions per a predetermined period of time.

2. The user terminal according to claim 1, wherein the given information comprises broadcast information that is transmitted from the radio base station in a predetermined bandwidth in a center of the system bandwidth,

wherein the decision section decides a frequency position for a predetermined SIB (System Information Block) to be allocated based on the broadcast information.

3. The user terminal according to claim 1, wherein the given information comprises a plurality of frequency position candidates at which broadcast information being transmitted to dedicated communicable user terminals on the narrow bandwidth can be allocated,

wherein the decision section decides a frequency position at which a predetermined SIB (System Information Block) is allocated based on the plurality of frequency position candidates.

4. The user terminal according to claim 1, further comprising:

a transmitting section configured to transmit a PRACH (Physical Random Access Channel) to the radio base station,

wherein the receiving section receives a plurality of different broadcast information at different frequency positions, and

wherein the transmitting section transmits the PRACH based on broadcast information that is received at a frequency position that has the best reception quality out of the plurality of different broadcast information.

5. The user terminal according to claim 1, wherein the given information is included in RRC signaling that is transmitted from the radio base station, and

wherein the decision section decides a frequency position at which an EPDCCH (Enhanced Physical Downlink Control Channel) is allocated based on the information transmitted by RRC signaling.

6. The user terminal according to claim 5, wherein the given information is included in an EPDCCH transmitted from the radio base station, and

wherein the decision section decides a frequency position at which a PDSCH (Physical Downlink Shared Channel) is allocated based on the information included in the EPDCCH.

7. The user terminal according to claim 6, wherein the PDSCH is arranged in a different subframe from a subframe in which the EPDCCH is arranged.

8. The user terminal according to claim 7, wherein the receiving section receives information on a plurality of radio resource groups, which are PDSCH allocation candidates, from the radio base station by higher layer signaling or the broadcast information, and

wherein the decision section selects one of the plurality of radio resource groups based on a predetermined indicator within a DCI (Downlink Control Information) included in the EPDCCH, and decides a frequency position at which the PDSCH is to be allocated in the selected radio resource group.

9. A radio base station 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 radio base station comprising:

a transmission signal generating section configured to generate a control signal and a data signal; and

a control section configured to control allocation of the control signal and the data signal on the narrow bandwidth,

wherein the control section arranges the narrow bandwidth at different frequency positions per a predetermined period of time.

10. A radio communication method for a user terminal 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 radio communication method comprising:

deciding a frequency position for the narrow bandwidth to be arranged, based on given information; and

receiving a control signal and a data signal that are allocated on the narrow bandwidth based on the frequency position,

wherein the narrow bandwidth is arranged at different frequency positions per a predetermined period of time.