WIRELESS COMMUNICATION SYSTEM, BASE STATION DEVICE, MOBILE STATION DEVICE, AND MACRODIVERSITY SELECTION METHOD

• US 20090137237A1
• Filed: 09/11/2006
• Published: 05/28/2009
• Est. Priority Date: 09/26/2005
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Nakashima, Daiichiro, Fukumasa, Hidenobu
• Granted Patent: US 8,219,042 B2
• Time in Patent Office: Days
• US Class Current: 455/422.100
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A wireless communication system, a base station device, a mobile station device, and a macrodiversity selection method of the invention, in a base station device including a macrodiversity function among a plurality of sectors, select a macrodiversity method for the mobile station device from a plurality of macrodiversity methods, in accordance with a predetermined determination reference based on reception conditions of the mobile station device.

Claims

1. A base station device comprising a macrodiversity function between a plurality of sectors that selects, in accordance with a predetermined determination reference based on reception conditions of a mobile station device, a macrodiversity method to be used with respect to the mobile station device from among a plurality of macrodiversity methods.

2. The base station device according to claim 1, which selects one of a first macrodiversity method of transmitting a signal created from identical information in a plurality of sectors from the sectors, and a second macrodiversity method of transmitting signal created from different information in a plurality of sectors from the sectors such as to suppress interference to an arbitrary sector, in accordance with a predetermined determination reference based on reception conditions of the mobile station device.

3. The base station device according to claim 2, which detects the location of the mobile station device and, when the mobile station device is located at a sector edge near the center of a cell, selects the second macrodiversity method, and, when the mobile station device is located at a sector edge near a cell edge, selects the first macrodiversity method.

4. The mobile station device according to claim 2, which selects whether to use macrodiversity based the reception power of a self sector, being a sector connected at the mobile station device, and the difference between the reception powers of the self sector and another sector, being one which is not connected at the mobile station device, and selects a macrodiversity method to be used.

5. The mobile station device according to claim 2, which selects whether to use macrodiversity based on the reception power of the self sector at the mobile station device, and a received signal to interference plus noise ratio of the self sector, and selects a macrodiversity method to be used.

6. The mobile station device according to claim 2, which selects whether to use macrodiversity based on the reception power of the self sector at the mobile station device, and the difference between the received signal to interference plus noise ratios of the self sector and another sector, and selects a macrodiversity method to be used.

7. The base station device according to claim 4, which further selects whether to use macrodiversity based on the difference in reception powers between the self sector and an adjacent cell, and selects a macrodiversity method to be used.

8. The base station device according to claim 4, which further selects whether to use macrodiversity based on the reception power of an adjacent cell, and selects a macrodiversity method to be used.

9. The base station device according to claim 2, which selects whether to use macrodiversity based on the received signal to interference plus noise ratio of an adjacent cell at the mobile station device, and the received signal to interference plus noise ratio of the self sector, and selects a macrodiversity method to be used.

10. The base station device according to claim 2, which selects whether to use macrodiversity based on the received signal to interference plus noise ratio of an adjacent cell at the mobile station device, and the difference between the received signal to interference plus noise ratios of the self sector and another sector, and selects a macrodiversity method to be used.

11. The base station device according to claim 2, which uses soft-combining, being a method of transmitting signals that are identical among the sectors, as the first macrodiversity method.

12. The base station device according to claim 2, which uses space time transmit diversity, being a method of transmitting signals that are encoded by space-time encoding between the sectors, as the first macrodiversity method.

13. The base station device according to claim 2, which uses, as the first macrodiversity method, a method of calculating a transmit weight based on channel information of the mobile station device in each sector, and transmitting a signal after multiplying the calculated weight with each sector.

14. The base station device according to claim 2, which uses, as the second macrodiversity method, fast sector selection with transmission muting, being a method that transmits a signal only from an arbitrary sector and does not transmit from remaining sectors.

15. The base station device according to claim 2, which uses, as the second macrodiversity method, a method of transmitting a signal at normal transmission power only from an arbitrary sector, and transmits at reduced transmission power from remaining sectors.

16. The base station device according to claim 11, which selects a macrodiversity method based on channel phase information from the base station device to the mobile station device, selecting the second macrodiversity method when the channel phase difference is greater than a predetermined threshold, and selecting soft-combining when it is smaller than the predetermined threshold.

17. A mobile station device which transmits a selection request signal for a first macrodiversity method and a second macrodiversity method to the base station device according to claim 2.

18. A mobile station device which transmits at least one of the reception power of another sector at the mobile station device and the difference between the reception powers of the self sector and the other sector, and the reception power of the self sector, to the base station device according to claim 4.

19. A mobile station device which transmits the received signal to interference plus noise ratio of the self sector at the mobile station device, and the reception power of the self sector, to the base station device according to claim 5.

20. A mobile station device which transmits at least one of:

the received signal to interference plus noise ratio of the self sector at the mobile station device and the received signal to interference plus noise ratio of the other sector; and

the difference between the received signal to interference plus noise ratios of the self sector and the other sector,

and the reception power of the self sector, to the base station device according to claim 6.

21. The mobile station device according to claim 18, which further transmits the difference between the reception power of the self sector and an adjacent cell to the base station device according to claim 7.

22. The mobile station device according to claim 18, which further transmits the reception power of the adjacent cell to the base station device according to claim 7.

23. A mobile station device which transmits the received signal to interference plus noise ratio of a self sector in the mobile station device, and the received signal to interference plus noise ratio of an adjacent cell, to the base station device according to claim 7.

24. A mobile station device which transmits at least one of:

the received signal to interference plus noise ratio of the self sector at the mobile station device and the received signal to interference plus noise ratio of the other sector; and

the difference between the received signal to interference plus noise ratios of the self sector and the other sector,

and the received signal to interference plus noise ratio of an adjacent cell, to the base station device according to claim 10.

25. The mobile station device according to claim 18, which extracts a phase difference between channels of the self sector and the other sector, and transmits it to the base station device according to claim 16.

26. A mobile station device which selects whether to use macrodiversity in the base station device according to claim 4, selects a macrodiversity method to be used, and transmits a selection request signal for the first macrodiversity method and the second macrodiversity method to the base station device.

27. A macrodiversity selection method of selecting a first macrodiversity method of transmitting a signal created from identical information in a plurality of sectors from the sectors, and a second macrodiversity method of transmitting signal created from different information in a plurality of sectors from the sectors such as to suppress interference to an arbitrary sector, in accordance with a predetermined determination reference based on reception conditions of the mobile station device.

28. The macrodiversity selection method according to claim 27, which selects whether to use macrodiversity based on the reception power of the self sector, being the connected sector, and on the difference the reception powers of the self sector and another sector, and selects a macrodiversity method to be used.

29. The macrodiversity selection method according to claim 27, which selects whether to use macrodiversity based on the reception power of the self sector, being the connected sector, and on the received signal to interference plus noise ratio of the self sector, and selects a macrodiversity method to be used.

30. The macrodiversity selection method according to claim 27, which selects whether to use macrodiversity based on the reception power of the self sector, being the connected sector, and the difference between the received signal to interference plus noise ratios of the self sector and another sector, and selects a macrodiversity method to be used.

31. The macrodiversity selection method according to claim 28, which further selects whether to use macrodiversity based on the difference between the reception powers of the self sector and an adjacent cell, and selects a macrodiversity method to be used.

32. The macrodiversity selection method according to claim 28, which further selects whether to use macrodiversity based on the reception power of an adjacent cell, and selects a macrodiversity method to be used.

33. The macrodiversity selection method according to claim 27, which selects whether to use macrodiversity based on the received signal to interference plus noise ratio of an adjacent cell, and the received signal to interference plus noise ratio of the self sector, and selects a macrodiversity method to be used.

34. The macrodiversity selection method according to claim 27, which selects whether to use macrodiversity based on the received signal to interference plus noise ratio of an adjacent cell, and the difference between the received signal to interference plus noise ratios of the self sector and another sector, and selects a macrodiversity method to be used.

35. The macrodiversity selection method according to claim 28, which, based on channel phase information from the base station device to the mobile station device, when the channel phase difference is greater than a predetermined threshold, selects the second macrodiversity method that transmits a signal created from different information in a plurality of sectors from the sectors such as to suppresses interference to an arbitrary sector, and, when the channel phase difference is smaller than the predetermined threshold, selects soft-combining as a first macrodiversity method that transmits signals that are identical among the sectors.

36. A wireless communication system that selects macrodiversity using the macrodiversity selection method according to claim 27 at a base station device or a mobile station device.