User terminal, radio base station, radio communication system and radio communication method

Patent metadata

Field	Value
Publication number	US-2018124752-A1
Application number	US-201615572807-A
Country	US
Kind code	A1
Filing date	May 13, 2016
Priority date	May 14, 2015
Publication date	May 3, 2018
Grant date	—

Abstract

The present invention is designed to reduce the decrease of throughput in communication by user terminals that are limited to using a partial narrow band in a system band as a band for their use. According to one aspect of the present invention, a user terminal, in which the band to use is limited to a partial narrow band in a system band, has a control section that selects a predetermined narrow band set that is formed with a plurality of narrow bands, and a receiving section that receives a downlink signal in a narrow band that is included in the predetermined narrow band set, and the control section selects the predetermined narrow band set from a plurality of narrow band sets, to which different frequency shifts are applied.

First claim

1 . A user terminal, in which a band to use is limited to a partial narrow band in a system band, the user terminal comprising:
a control section that selects a predetermined narrow band set that is formed with a plurality of narrow bands; and a receiving section that receives a downlink signal in a narrow band that is included in the predetermined narrow band set, wherein the control section selects the predetermined narrow band set from a plurality of narrow band sets, to which different frequency shifts are applied.

2 . The user terminal according to claim 1 , wherein among the plurality of narrowband sets, one narrow band set is applied with a frequency shift of 2 to 4 PRBs (Physical Resource Blocks) with respect to anotye narrow band set.

3 . The user terminal according to claim 1 , wherein:
the receiving section receives DCI (Downlink Control Information); and the control section selects the predetermined narrow band set based on the DCI.

4 . The user terminal according to claim 1 , wherein the receiving section receives a PDSCH (Physical Downlink Shared Channel), and detects a downlink control channel in a narrow band in which the PDSCH is received.

5 . The user terminal according to claim 1 , wherein the receiving section performs a receiving process of a signal that is subject to same-subframe scheduling or a signal that is subject to cross-subframe scheduling, based on a relationship between locations of PRBs of a downlink control channel and locations of PRBs of a PDSCH specified in an RA (Resource Allocation) field in DCI transmitted in the downlink control channel.

6 . The user terminal according to claim 5 , wherein, when the locations of the PRBs of the downlink control channel and the locations of the PRBs of the PDSCH specified in the RA field are in a same narrow band and in different PRBs, the receiving section receives the signal that is subject to same-subframe scheduling.

7 . The user terminal according to claim 5 , wherein, when the locations of the PRBs of the downlink control channel and the locations of the PRBs of the PDSCH specified in the RA field are in a same narrow band and in at least partly overlapping PRBs, the receiving section receives the signal that is subjected to cross-subframe scheduling.

8 . A radio base station that communicates with a user terminal, in which a band to use is limited to a partial narrow band in a system band, the radio base station comprising:
a control section that applies different frequency shifts to each of a plurality of narrow band sets that are formed with a plurality of narrow bands; and a transmission section that transmits a downlink signal in a narrow band included in the predetermined narrow band set.

9 . (canceled)

10 . A radio communication method for allowing a user terminal, in which a band to use is limited to a partial narrow band in a system band, to communicate with a radio base station, the radio communication method comprising the steps of:
selecting a predetermined narrow band set that is formed with a plurality of narrow bands; and receiving a downlink signal in a narrow band that is included in the predetermined narrow band set, wherein the predetermined narrow band set is selected from a plurality of narrow band sets, to which different frequency shifts are applied.

11 . The user terminal according to claim 2 , wherein the receiving section receives DCI (Downlink Control Information); and the control section selects the predetermined narrow band set based on the DCI.

12 . The user terminal according to claim 2 , wherein the receiving section receives a PDSCH (Physical Downlink Shared Channel), and detects a downlink control channel in a narrow band in which the PDSCH is received.

13 . The user terminal according to claim 3 , wherein the receiving section receives a PDSCH (Physical Downlink Shared Channel), and detects a downlink control channel in a narrow band in which the PDSCH is received.

14 . The user terminal according to claim 2 , wherein the receiving section performs a receiving process of a signal that is subject to same-subframe scheduling or a signal that is subject to cross-subframe scheduling, based on a relationship between locations of PRBs of a downlink control channel and locations of PRBs of a PDSCH specified in an RA (Resource Allocation) field in DCI transmitted in the downlink control channel.

15 . The user terminal according to claim 3 , wherein the receiving section performs a receiving process of a signal that is subject to same-subframe scheduling or a signal that is subject to cross-subframe scheduling, based on a relationship between locations of PRBs of a downlink control channel and locations of PRBs of a PDSCH specified in an RA (Resource Allocation) field in DCI transmitted in the downlink control channel.

16 . The user terminal according to claim 4 , wherein the receiving section performs a receiving process of a signal that is subject to same-subframe scheduling or a signal that is subject to cross-subframe scheduling, based on a relationship between locations of PRBs of a downlink control channel and locations of PRBs of a PDSCH specified in an RA (Resource Allocation) field in DCI transmitted in the downlink control channel.

Assignees

• Ntt Docomo Inc

Inventors

• Takeda Kazuaki
• Moroga Hideyuki
• Nagata Satoshi
• Mu Qin
• Liu Liu

Classifications

• H04W72/23 Primary

  in the downlink direction of a wireless link, i.e. towards a terminal · CPC title

• H04L5/0094 Primary

  Indication of how sub-channels of the path are allocated · CPC title

• H04W72/0453

  Resources in frequency domain, e.g. a carrier in FDMA · CPC title

• H04W72/042 Primary

  Electricity · mapped topic

• H04L5/001

  the frequencies being arranged in component carriers · CPC title