# US 7,613,432 B2 · Method of controlling mobile communication system, control device, and mobile communication system

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- Number: US 7,613,432 B2
- Document ID: US7613432B2
- Status: Granted
- Kind: B2
- Application number: 11/493,563
- Filed: 2006-07-27
- Published: 2007-02-15
- Granted: 2009-11-03
- Earliest claimed: 2005-08-09
- Assignees: Ntt Docomo, Inc.
- Inventors: Hiroyuki Ishii; Takuya Sato; Hidehiro Ando
- Web page: https://patentgrep.com/patent/US7613432B2

## CPC

- H04B 7/0689: {using different transmission schemes, at least one of them being a diversity transmission scheme}
- H04B 7/0634: {Antenna weights or vector/matrix coefficients}
- H04B 7/0654: {at the receiver, e.g. antenna verification at mobile station}
- H04L 1/0001: {Systems modifying transmission characteristics according to link quality, e.g. power backoff (adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04)}
- H04L 1/0017: {where the mode-switching is based on Quality of Service requirement}
- H04L 1/0625: {Transmitter arrangements}
- H04B: TRANSMISSION
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)

## Abstract

A mobile communication system controls switching a transmission diversity system for each channel, and improves the quality of the channel. When the channel type in an uplink is a channel for transmitting voice, open loop transmission diversity is used (steps S1→S3). When the channel type in an uplink is a channel for transmitting a packet, closed loop transmission diversity is used (steps S1→S2). Since the open loop transmission diversity or the closed loop transmission diversity which ever is more appropriate can be used, a transmission diversity system can be appropriately switched for each channel, thereby improving the quality of the channel.

## Claims

### Claim 1

A method of controlling a mobile communication system, comprising a radio base station to which transmission diversity of performing radio transmission using a plurality of antennas is applied, and a mobile station for communicating with the radio base station, wherein a transmission diversity system is determined according to information about a channel in an uplink from the mobile station to the radio base station and wherein the information about the channel in the uplink is a channel type, open loop transmission diversity is used when the channel type refers to a channel for transmitting voice, and closed loop transmission diversity is used when the channel type refers to a channel for transmitting a packet.

### Claim 2 (depends on 1)

The method of controlling a mobile communication system according to claim 1, wherein the information about the channel in the uplink is a signal-to-interference power ratio of a physical control channel of the uplink, and a signal-to-interference power ratio of pilot signals based on at least one of which a transmission diversity system is determined.

### Claim 3

A method of controlling a mobile communication system, comprising a radio base station to which transmission diversity of performing radio transmission using a plurality of antennas is applied, and a mobile station for communicating with the radio base station,
wherein a transmission diversity system is determined according to information about a channel in an uplink from the mobile station to the radio base station,
wherein the information about the channel in the uplink is a transmission rate of a channel in an uplink, an amplitude ratio of a control channel to a data channel, a transmission time interval, a target error rate, and a slot format, based on at least one of which a transmission diversity system is determined,
and wherein the transmission diversity system control means uses open loop transmission diversity when the transmission rate of the channel in the uplink is low, and uses closed loop transmission diversity when the transmission rate of the uplink is high.

### Claim 4

A control device which controls execution of transmission diversity of a radio base station for performing wireless transmission with a mobile station using a plurality of antennas, comprising transmission diversity system control means for determining a transmission diversity system according to information about a channel in an uplink from the mobile station,
wherein the information about the channel in the uplink is a channel type, and the transmission diversity system control means uses open loop transmission diversity when the channel type refers to a channel for transmitting voice, and uses closed loop transmission diversity when the channel type refers to a channel for transmitting a packet.

### Claim 5 (depends on 4)

The control device according to claim 4, wherein the information about the channel in the uplink is a signal-to-interference power ratio of a physical control channel of the uplink, and a signal-to-interference power ratio of pilot signals, based on at least one of which the transmission diversity system control means determines a transmission diversity system.

### Claim 6 (depends on 5)

A mobile communication system which comprises a mobile station, a radio base station for performing wireless transmission to the mobile station using a plurality of antennas, and a radio network controller for controlling the mobile station and the radio base station, and controls execution of transmission diversity of the radio base station, wherein the control device according to claim 5 is provided for at least one of the mobile station, the radio base station, and the radio network controller.

### Claim 7 (depends on 4)

A mobile communication system which comprises a mobile station, a radio base station for performing wireless transmission to the mobile station using a plurality of antennas, and a radio network controller for controlling the mobile station and the radio base station, and controls execution of transmission diversity of the radio base station, wherein the control device according to claim 4 is provided for at least one of the mobile station, the radio base station, and the radio network controller.

### Claim 8

A control device which controls execution of transmission diversity of a radio base station for performing wireless transmission with a mobile station using a plurality of antennas, comprising transmission diversity system control means for determining a transmission diversity system according to information about a channel in an uplink from the mobile station,
wherein the information about the channel in the uplink is a transmission rate of a channel in the uplink, an amplitude ratio of a control channel to a data channel, a transmission time interval, a target error rate, and a slot format, based on at least one of which the transmission diversity system control means determines a transmission diversity system,
and wherein the transmission diversity system control means uses open loop transmission diversity when the transmission rate of the channel in the uplink is low, and uses closed loop transmission diversity when the transmission rate of the uplink is high.

### Claim 9 (depends on 8)

A mobile communication system which comprises a mobile station, a radio base station for performing wireless transmission to the mobile station using a plurality of antennas, and a radio network controller for controlling the mobile station and the radio base station, and controls execution of transmission diversity of the radio base station, wherein the control device according to claim 8 is provided for at least one of the mobile station, the radio base station, and the radio network controller.