Method and system for optimizing a traffic channel in a wireless communications system

• US 5,960,350 A
• Filed: 12/05/1996
• Issued: 09/28/1999
• Est. Priority Date: 12/05/1996
• Status: Expired due to Term

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Clark, Michael Paul, Rozanski, Walter Joseph Jr., Schorman, Eric Reed
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): BANKS HAROLD, MARSHA DENISE
• Application Number:
  US08/760,498
• Time in Patent Office: 1,027 Days
• Field of Search: 455/422, 455/450, 455/517, 455/436, 455/162, 455/67.1, 455/63, 455/67.3, 455/65, 455/161.3, 455/179.1, 455/226.2, 455/513, 370/335, 370/342, 370/350, 370/331, 370/332
• US Class Current: 455/450
• CPC Class Codes: H01Q 3/2605 Array of radiating elements provided with a feedback control over the element weights, e.g. adaptive arrays
• CPC Class Codes: H04B 7/0602 using antenna switching H04B7/0686 takes precedence; antenna beam directivity switching H01Q3/24
• CPC Class Codes: H04W 16/28 using beam steering

Abstract

In a wireless communications system (20), a beacon having a first radiation pattern (28) covering a portion of a subscriber service area (34) covered by a base station is transmitted. A subscriber (36) reception quality is then measured to produce a first beacon quality measurement (210). Thereafter, the first radiation pattern is changed to a second radiation pattern (32, 212), and a subscriber reception quality of the beacon transmitted with a second radiation pattern is measured to produce a second beacon quality measurement (214). In response to the first and second beacon quality measurements, a traffic channel radiation pattern (32) is selected (218), wherein such radiation pattern covers a portion of the subscriber service area. In a preferred embodiment, the beacon carrier frequency is the same as the traffic channel carrier frequency.

Claims

1. A method of optimizing a traffic channel in a wireless communication system:

transmitting a beacon having a first radiation pattern covering a portion of a subscriber service area covered by a base station, wherein said beacon is a spread spectrum signal that is at least substantially orthogonal to said traffic channel;

measuring a subscriber reception quality of said beacon transmitted with said first radiation pattern to produce a first beacon quality measurement;

changing said first radiation pattern to a second radiation pattern;

measuring a subscriber reception quality of said beacon transmitted with said second radiation pattern to produce a second beacon quality measurement; and

in response to said first and second beacon quality measurements, selecting a traffic channel radiation pattern having a radiation pattern covering a portion of said subscriber service area covered by said base station.

2. The method of optimizing a traffic channel according to claim 1 wherein said beacon has the same frequency as said traffic channel.

3. The method of optimizing a traffic channel according to claim 1 wherein said step of selecting a traffic channel radiation pattern further includes the steps of:

comparing said first and second beacon quality measurements; and

selecting a traffic channel radiation pattern substantially similar to said second radiation pattern if said second beacon quality measurement exceeds said first beacon quality measurement.

4. The method of optimizing a traffic channel according to claim 1 further including the steps of:

repeating said changing and measuring steps using a plurality of radiation patterns each covering selected portions of said subscriber service area covered by said base station;

selecting one of said plurality of radiation patterns associated with a beacon quality measurement that exceeds a threshold; and

selecting a traffic channel radiation pattern in response to said selected one of said plurality of radiation patterns.

5. The method of optimizing a traffic channel according to claim 1 wherein said beacon quality measurement is a beacon signal strength measurement.

6. The method of optimizing a traffic channel according to claim 1 wherein said first radiation pattern covers a sector-shaped portion of said subscriber service area extending radially from said base station to the extent of said subscriber service area.

7. The method of optimizing a traffic channel according to claim 1 wherein said beacon is a time-offset spreading code.

8. The method of optimizing a traffic channel according to claim 1 further including transferring said first and second beacon quality measurements from said subscriber to said base station via an uplink traffic channel.

9. A system for optimizing a traffic channel in a wireless communication system:

means for transmitting a beacon having a first radiation pattern covering a portion of a subscriber service area covered by a base station, wherein said beacon is a spread spectrum signal that is at least substantially orthogonal to said traffic channel;

means for measuring a subscriber reception quality of said beacon transmitted with said first radiation pattern to produce a first beacon quality measurement;

means for changing said first radiation pattern to a second radiation pattern;

means for measuring a subscriber reception quality of said beacon transmitted with said second radiation pattern to produce a second beacon quality measurement; and

means for selecting a traffic channel radiation pattern having a radiation pattern covering a portion of said subscriber service area covered by said base station in response to said first and second quality measurements.

10. The system for optimizing a traffic channel according to claim 9 wherein said beacon has the same frequency as said traffic channel.

11. The system for optimizing a traffic channel according to claim 9 wherein said means for selecting a traffic channel radiation pattern further includes:

means for comparing said first and second beacon quality measurements; and

means for selecting a traffic channel radiation pattern substantially similar to said second radiation pattern if said second beacon quality measurement exceeds said first beacon quality measurement.

12. The system for optimizing a traffic channel according to claim 9 further including:

means for repeating said changing and measuring steps using a plurality of radiation patterns each covering selected portions of said subscriber service area covered by said base station;

means for selecting one of said plurality of radiation patterns associated with a beacon quality measurement that exceeds a threshold; and

means for selecting a traffic channel radiation pattern in response to said selected one of said plurality of radiation patterns.

13. The system for optimizing a traffic channel according to claim 9 wherein said beacon quality measurement is a beacon strength measurement.

14. The system for optimizing a traffic channel according to claim 9 wherein said first radiation pattern covers a sector-shaped portion of said subscriber service area extending radially from said base station to the extent of said subscriber service area.

15. The system for optimizing a traffic channel according to claim 9 wherein said beacon is a time-offset spreading code.

16. The system for optimizing a traffic channel according to claim 9 further including means for transferring said first and second beacon quality measurements from said subscriber to said base station via an uplink traffic channel.