BASE STATION, COMMUNICATION METHOD, AND MOBILE STATION

• US 20120208599A1
• Filed: 04/24/2012
• Published: 08/16/2012
• Est. Priority Date: 10/30/2009
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: TANAKA, Yoshinori
• Granted Patent: US 8,483,747 B2
• Time in Patent Office: Days
• US Class Current: 455/561
• CPC Class Codes: 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
• CPC Class Codes: H04J 11/0053 using co-ordinated multipoint transmission/reception co-ordinated antenna or beam-forming aspects H04B7/022
• CPC Class Codes: H04W 72/27 between access points
• CPC Class Codes: H04W 72/542 using measured or perceived quality

Abstract

A base station requests cooperative transmission of a base station forming a nearby cell that is near a mobile station. The base station further includes an acquirer that acquires a reception power for each nearby cell of the mobile station; a calculator that calculates a value for each acquired reception power, weighted by a coefficient of the nearby cell; and a selector that based on each value calculated by the calculator and from among the nearby cells, selects a cell of which the cooperative transmission is to be requested.

Claims

1. A base station that requests cooperative transmission of a base station forming a nearby cell that is near a mobile station, the base station comprising:

an acquirer that acquires a reception power for each nearby cell of the mobile station; and

a selector that based on each value for each acquired reception power weighted by a coefficient of the nearby cell and from among the nearby cells, selects a cell of which the cooperative transmission is to be requested.

2. The base station according to claim 1 and further comprising

a controller that performs the cooperative transmission using the cell selected by the selector.

3. The base station according to claim 1, further comprising:

a calculator, wherein

the acquirer acquires the reception power of a local cell of the mobile station and the reception power of each non-local cell that are among the nearby cells and different from the local cell, and

the calculator calculates a ratio of the reception power of each non-local cell with respect to the reception power of the local cell, the ratio being weighted by the coefficient of the non-local cell.

4. The base station according to claim 1, wherein

the selector compares the each value with a threshold and based on a comparison result, selects the cell of which the cooperative transmission is to be requested.

5. The base station according to claim 3 and further comprising

a setter that sets the coefficient of each nearby cell, wherein

the setter, for a non-local cell among the non-local cells and having a relatively small delay of intercellular communication with the local cell, sets a coefficient that is larger than that set for a non-local cell having a relatively large delay.

6. The base station according to claim 5 and further comprising

a delay acquirer that acquires the delay of each non-local cell, wherein

the setter sets the coefficients, based on the acquired delays.

7. The base station according to claim 5, wherein

the setter, for a non-local cell among the non-local cells and for which the product of traveling speed of the mobile station and the delay is relatively small, sets a coefficient that is larger than that set for a non-local cell for which the product is relatively large.

8. The base station according to claim 7 and further comprising

an estimator that estimates the traveling speed of the mobile station, wherein

the setter sets the coefficients, based on the traveling speed estimated by the estimator.

9. The base station according to claim 3 and further comprising

a setter that sets the coefficient of each nearby cell, wherein

the setter sets the coefficient of each nearby cell, based on an applicable cooperative communication scheme in the non-local cell.

10. The base station according to claim 9 and further comprising

a scheme acquirer that acquires the cooperative communication scheme from each non-local cell, wherein

the setter sets the coefficients, based on the cooperative communication schemes acquired by the scheme acquirer.

11. A base station that requests cooperative reception of a base station forming a nearby cell that is near a mobile station, the base station comprising:

an acquirer that acquires interference power that is from the mobile station to each nearby cell of the mobile station; and

a selector that based on each value for each acquired interference power weighted by a coefficient for the nearby cell and from among the nearby cells, selects a cell of which the cooperative reception is to be requested.

12. The base station according to claim 11, wherein

the acquirer acquires as the interference power, propagation loss from each nearby cell to the mobile station.

13. A communication method of requesting cooperative transmission of a base station forming a nearby cell that is near a mobile station, the communication method comprising:

acquiring a reception power for each nearby cell of the mobile station; and

selecting based on each value for each acquired reception power weighted by a coefficient of the nearby cell, a cell of which the cooperative transmission is to be requested.

14. A communication method of requesting cooperative reception of a base station forming a nearby cell that is near a mobile station, the communication method comprising:

acquiring interference power that is from the mobile station to each nearby cell of the mobile station; and

selecting based on each value for each acquired interference power weighted by a coefficient for the nearby cell, a cell of which the cooperative reception is to be requested.

15. A mobile station comprising:

a receiver that receives data cooperatively transmitted from a portion of or all cells selected from among cells nearby the mobile station, the cells being selected based on values that are for reception powers from the nearby cells and are weighted by cell-specific coefficients.

16. A mobile station comprising:

a transmitter that transmits data to be cooperatively received by a portion of or all cells selected from among cells nearby the mobile station, the cells being selected based on values that are for interference power that is from the mobile station to each nearby cell and that are weighted by cell-specific coefficients.