Mobile station and weighting control method

• US 20060209883A1
• Filed: 06/24/2005
• Published: 09/21/2006
• Est. Priority Date: 03/16/2005
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Suzuki, Masaaki
• Granted Patent: US 7,583,981 B2
• Time in Patent Office: Days
• US Class Current: 370/465
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04
• CPC Class Codes: H04B 7/0619 using feedback from receiving side feedback signaling for adaptive modulation/coding H04L1/0001
• CPC Class Codes: H04B 7/0634 Antenna weights or vector/matrix coefficients
• CPC Class Codes: H04B 7/0654 at the receiver, e.g. antenna verification at mobile station
• CPC Class Codes: H04B 7/0689 using different transmission schemes, at least one of them being a diversity transmission scheme
• CPC Class Codes: H04W 52/40 during macro-diversity or soft handoff

Abstract

In a first state in which the same voice data is being received from a plurality of base stations on a first channel (DPCH) and a packet is not being received on a second channel (HS-PDSCH), weight is decided in such a manner that first weighting is applied to signals received from respective ones of the base stations and prescribed control is performed based upon the signals to which the first weighting has been applied. In a second state in which the same voice data is being received from a plurality of base stations on the first channel and a packet is not being received on the second channel, weight is decided in such a manner that second weighting is applied to signals received from respective ones of the base stations and prescribed control is performed based upon the signals to which the second weighting has been applied. When the second state has changed to the first state, transition time (protection time) TMR at which there is a transition from second weighting to first weighting is controlled adaptively.

Claims

1. A method of controlling weighting of a mobile station in a communication system for transmitting the same data from a plurality of base stations to a mobile station on a first channel and transmitting other data from one base station to the mobile station intermittently on a second channel during communication on the first channel, said method comprising:

in a first state in which the same data is being received from the plurality of base stations on the first channel and data is not being received on the second channel, a step of deciding weight in such a manner that first weighting is applied to signals received from respective ones of the base stations and performing prescribed control based upon the signals to which the first weighting has been applied;

in a second state in which the same data is being received from the plurality of base stations on the first channel and data is being received from one base station on the second channel, a step of deciding a weight in such a manner that second weighting is applied to signals received from respective ones of the base stations and performing the prescribed control based upon the signals to which the second weighting has been applied; and

an adaptive control step of adaptively controlling timing of transition from the second weighting to the first weighting when the second state has changed to the first state.

2. The method according to claim 1, wherein said adaptive control step includes:

an interval monitoring step of monitoring an interval at which the second state occurs; and

when the second state has changed to the first state, adaptively deciding timing of transition from the second weighting to the first weighting based upon the interval.

3. The method according to claim 2, wherein if the interval is greater than a set interval, a transition is made from second weighting to first weighting immediately when the second state has changed to the first state.

4. The method according to claim 2, wherein said interval monitoring step includes receiving, during communication, control information concerning whether or not data will be transmitted from a base station on the second channel, recognizing a change in state based upon this control information and monitoring the interval at which the second state occurs.

5. The method according to claim 2, wherein the second weighting is changed to the first weighting successively.

6. The method according to claim 1, wherein the weights of signals received from the plurality of base stations are equalized in the first weighting and the weight of a signal received from a base station that transmits data on the second channel is made greater than the weight of data received from another base station in the second weighting.

7. The method according to claim 6, wherein weight based upon the second weighting is decided in accordance with types of service of the first and second channels.

8. The method according to claim 1, wherein when the communication system is a transmit diversity communication system in which a base station transmits data on first and second channels using a plurality of antennas, phase rotation information that is fed back to each base station is decided based upon the signals that have been weighted.

9. A mobile station in a communication system for transmitting the same data from a plurality of base stations to a mobile station on a first channel and transmitting other data from one base station to the mobile station intermittently on a second channel during communication on the first channel, said mobile station comprising:

a first receiver for receiving the same data from the plurality of base stations on the first channel;

a second receiver for receiving other data from one base station intermittently on a second channel;

a weight calculation unit which, in a first state in which the same data is being received from the plurality of base stations on the first channel and data is not being received from any base station on the second channel, is for deciding weight in such a manner that first weighting is applied to signals received from respective ones of the base stations, and in a second state in which the same data is being received from the plurality of base stations on the first channel and data is being received from one base station on the second channel, is for deciding a weight in such a manner that second weighting is applied to signals received from respective ones of the base stations;

a transition timing decision unit for deciding a timing at which there is a transition from the second weighting to the first weighting when the second state has changed to the first state; and

a controller for performing prescribed control based upon the weighted signals.

10. The mobile station according to claim 9, wherein said transition timing decision unit includes:

an interval monitoring unit for monitoring intervals at which the second state occurs; and

a timing decision unit for deciding, by statistical processing of the intervals, the timing at which there is a transition from the second weighting to the first weighting.

11. The mobile station according to claim 10, wherein if said interval is greater than a set time, then said transition timing decision unit decides that a transition is to be made from second weighting to first weighting immediately when the second state has changed to the first state.

12. The mobile station according to claim 10, wherein said interval monitoring unit includes:

a control-information demodulator/decoder for demodulating and decoding control information concerning whether or not data will be transmitted from a base station on the second channel during communication; and

a state-change identification unit for recognizing a change in state based upon the control information.

13. The mobile station according to claim 10, wherein said weight calculation unit includes means for causing a successive change from the second weighting to the first weighting.

14. The mobile station according to claim 9, wherein said weight calculation unit equalizes the weights of signals received from the plurality of base stations in the first weighting, and makes the weight of data received from a base station that transmits data on the second channel greater than the weight of data received from another base station in the second weighting.

15. The mobile station according to claim 14, further comprising a weight holding unit for holding the second weight in association with types of service of the first and second channels;

wherein said weight calculation unit decides the weight of the second weighting in accordance with types of service of the first and second channels.

16. The mobile station according to claim 9, wherein in a transmit diversity communication system for transmitting data from a base station on first and second channels using a plurality of antennas, said controller decides phase rotation information, which is fed back to the base station, based upon the weighted signals from each of the base stations.

17. A mobile station for receiving data of the same content from both a first base station, which transmits data of the same content by antenna diversity using first and second antennas, and a second base station, which transmits data of the same content by antenna diversity using third and fourth antennas, comprising:

a weighting phase controller for changing a length of time over which phase control relating to the first and second antennas of the first base station is performed at a priority higher than that of phase control relating to the third and fourth antennas of the second base station in accordance with a reception interval of HS-PDSCH transmitted using the first and second antennas.

18. The mobile station according to claim 17, wherein the reception interval is decided based upon result of measurement by a measurement unit that measures a reception interval of data via HS-PDSCH transmitted by the first base station using the first and second antennas, or based upon information transmitted from the first base station.

19. A mobile station for receiving data of the same content from both a first base station, which transmits data of the same content by antenna diversity using first and second antennas, and a second base station, which transmits data of the same content by antenna diversity using third and fourth antennas, said mobile station having:

a receiver which, in a case where the first base station is a base station that transmits HS-PDSCH to the mobile station using the first and second antennas, is for receiving a command signal from said first base station, said command signal being a signal for giving phase control relating to the first and second antennas of the first base station a higher priority than phase control relating to the third and fourth antennas of the second base station; and

a transmitter for transmitting a signal for phase control in accordance with the command signal to the first and second base stations.

20. The base station according to claim 19, wherein the command signal is transmitted before transmission of HS-SCCH, which gives advance notice of transmission of HS-PDSCH.