# US 9,438,391 B2 · Mobile communication method, radio base station, and mobile station

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- Number: US 9,438,391 B2
- Document ID: US9438391B2
- Status: Granted
- Kind: B2
- Application number: 14/349,114
- Filed: 2012-10-01
- Published: 2014-09-04
- Granted: 2016-09-06
- Earliest claimed: 2011-10-03
- Assignees: Ntt Docomo, Inc.
- Applicants: Ntt Docomo, Inc.
- Inventors: Hideaki Takahashi; Wuri Andarmawanti Hapsari; Satoshi Nagata
- Web page: https://patentgrep.com/patent/US9438391B2

## CPC

- H04L 5/0035: {Resource allocation in a cooperative multipoint environment}
- H04B 7/024: Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems
- H04L 1/0026: {Transmission of channel quality indication}
- H04W 24/08: Testing, {supervising or monitoring} using real traffic
- H04B 7/0626: {Channel coefficients, e.g. channel state information [CSI]}
- H04L 5/0091: {Signalling for the administration of the divided path, e.g. signalling of configuration information}
- H04L 2001/0092: {Error control systems characterised by the topology of the transmission link}
- H04W 48/12: using downlink control channel
- H04W 76/34: Selective release of ongoing connections
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)
- H04B: TRANSMISSION
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)

## Abstract

The addition and change of a CoMP transmission point performing a CoMP transmission/reception process is appropriately performed. A mobile communication method includes: a step of notifying, by a radio base station (eNB), configuration information of CSI-RS of a CoMP transmission point to a mobile station (UE) connected to a cell (#5) managed by the radio base station (eNB), when instructing an addition or change of the CoMP transmission point performing a CoMP transmission/reception process by “RRC Connection Reconfiguration”; a step of measuring, by the mobile station (UE), a CQI of the CoMP transmission point by using the CSI-RS of the CoMP transmission point, while performing the CoMP transmission/reception process; and a step of notifying, by the mobile station (UE), the CQI of the CoMP transmission point to the radio base station (eNB).

## Claims

### Claim 1

A mobile communication method comprising:
a step of notifying, by a radio base station, configuration information of a reference signal for a mobile station in a transmission point to the mobile station connected to a cell managed by the radio base station, when instructing an addition or change of the transmission point performing a coordinated multi-point transmission/reception process by an RRCConnectionReconfiguration including radioResourceConfigDedicated therein,
wherein an information element that notifies the configuration information of the reference signal for the mobile station in the transmission point, is set in the radioResourceConfigDedicated;
a step of measuring, by the mobile station, a channel quality of the transmission point by using the reference signal for the mobile station in the transmission point, while performing the coordinated multi-point transmission/reception process; and
a step of notifying, by the mobile station, the channel quality of the transmission point to the radio base station.

### Claim 2

A radio base station comprising:
a transmission unit configured to notify configuration information of a reference signal for a mobile station in a transmission point to the mobile station connected to a cell managed by the radio base station, when instructing an addition or change of the transmission point performing a coordinated multi-point transmission/reception process by an RRCConnectionReconfiguration including radioResourceConfigDedicated therein,
wherein an information element that notifies the configuration information of the reference signal for the mobile station in the transmission point, is set in the radioResourceConfigDedicated; and
a reception unit configured to acquire a channel quality of the transmission point, which is measured using the reference signal for the mobile station in the transmission point, from the mobile station, while performing the coordinated multi-point transmission/reception process.

### Claim 3

A mobile station comprising:
a reception unit connected to a cell managed by a radio base station, and configured to receive configuration information of a reference signal for the mobile station in a transmission point when a coordinated multi-point transmission/reception process is performed and an addition or change of a transmission point performing the coordinated multi-point transmission/reception process is instructed from the radio base station by an RRCConnectionReconfiguration including radioResourceConfigDedicated therein,
wherein an information element that notifies the configuration information of the reference signal for the mobile station in the transmission point, is set in the radioResourceConfigDedicated;
a processing unit configured to measure a channel quality of the transmission point by using the reference signal for the mobile station in the transmission point, while performing the coordinated multi-point transmission/reception process; and
a transmission unit configured to notify the channel quality of the transmission point to the radio base station.