Harmonized Adaptive Arrays

• US 20050075140A1
• Filed: 09/19/2004
• Published: 04/07/2005
• Est. Priority Date: 10/02/2003
• Status: Active Grant

• Current Assignee: Telcordia Legacy Inc.
• Original Assignee: Telcordia Technologies Incorporated (Telefonaktiebolaget LM Ericsson), Toshiba America Research Inc (Toshiba Corporation)
• Inventors: Famolari, David
• Granted Patent: US 7,720,509 B2
• Time in Patent Office: Days
• US Class Current: 455/562.100
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04W 16/28 using beam steering

Abstract

A system and method for harmonizing adaptive arrays for wireless communication systems. The system includes a basis beam that receives packet transmissions from stations. The system determines the angle of arrival of the packet transmissions and forms a select beam to cover at least one of the stations.

Claims

1. A method for adjusting beams in a wireless communication system comprising the steps of:

forming a basis beam;

listening for a transmission by a mobile station; and

forming a select beam to cover said mobile station.

2. The method according to claim 1, further comprising the step of:

terminating said select beam when said mobile station is no longer transmitting.

3. The method according to claim 1, further comprising the steps of:

determining antenna weights for said basis beam; and

determining antenna weights for said select beam.

15. The system according to claim 13, further comprising:

means for determining antenna weights for said basis beam; and

means for determining antenna weights for said select beam.

4. A method for updating a table in a wireless access point comprising the steps of:

determining when an entry for a station had been last updated;

determining if a time for said last update for said station is greater than a threshold; and

updating said entry for said station.

5. The method according to claim 4, said updating step further comprising the step of:

sending survey packets to said station.

6. The method according to claim 4, wherein said table includes angle of arrival information.

7. The method according to claim 4, wherein said table includes angle of arrival information computed from synchronization information received in a signal from said station.

8. A method for adjusting beams comprising the steps of:

determining if a station is covered by a basis beam;

adjusting said basis beam to cover said station.

9. The method according to claim 8, wherein an angle of arrival of said station is determined from header information contained in a packet received from said station and wherein said determining step determines if said station is covered by comparing said angle of arrival of said station with angles covered by said basis beam.

10. A method for adjusting beams comprising the steps of:

decoding a first part of a transmitted packet to determine the angle of arrival of a station that transmitted said packet;

forming a select beam to cover said station based on said angle of arrival; and

decoding a second part of a transmitted packet as received via said select beam.

11. The method according to claim 10, further comprising the step of:

updating an angle of arrival table in an access point with said determined angle of arrival information.

12. A method for adjusting beams comprising the steps of:

decoding a first part of a transmitted packet to determine the angle of arrival of a station that transmitted said packet;

adjusting a basis beam to ensure coverage of said station based on said angle of arrival; and

decoding a second part of a transmitted packet as received via a select beam.

13. A system for adjusting beams in a wireless communication system comprising:

means for forming a basis beam;

means for listening for a transmission by a mobile station; and

means for forming a select beam to cover said mobile station.

14. The system according to claim 13, further comprising:

means for terminating said select beam when said mobile station is no longer transmitting.

16. A system for updating a table in a wireless access point comprising:

means for determining when an entry for a station had been last updated;

means for determining if a time for said last update for said station is greater than a threshold; and

means for updating said entry for said station.

17. The system according to claim 16, said means for updating further comprising:

means for sending survey packets to said station.

18. The system according to claim 16, wherein said table includes angle of arrival information.

19. The system according to claim 16, wherein said table includes angle of arrival information computed from synchronization information received in a signal from said station.

20. A system for adjusting beams comprising:

means for determining if a station is covered by a basis beam; and

means for adjusting said basis beam to cover said station.

21. The system according to claim 20, wherein an angle of arrival of said station is determined from header information contained in a packet received from said station and wherein said means for determining determines if said station is covered by comparing said angle of arrival of said station with angles covered by said basis beam.

22. A system for adjusting beams comprising:

means for decoding a first part of a transmitted packet to determine the angle of arrival of a station that transmitted said packet;

means for forming a select beam to cover said station based on said angle of arrival; and

means for decoding a second part of a transmitted packet as received via said select beam.

23. The system according to claim 22, further comprising:

means for updating an angle of arrival table in an access point with said determined angle of arrival information.

24. A system for adjusting beams comprising:

means for decoding a first part of a transmitted packet to determine the angle of arrival of a station that transmitted said packet;

means for adjusting a basis beam to ensure coverage of said station based on said angle of arrival; and

means for decoding a second part of a transmitted packet as received via a select beam.

25. An access point comprising:

an antenna array;

one or more processors that receive packets from said antenna, said packets generated by mobile stations, said one or more processors decoding a first portion of said packets, determining the angle of arrival of said packets, and

outputting antenna array weights to said antenna array to steer a select beam to cover said mobile stations.

26. The access point according to claim 25, wherein said processor further outputs antenna array weights for adjusting a basis beam generated by said antenna array.