Coordination of beam forming in wireless communication systems

• US 7,373,176 B2
• Filed: 12/09/2003
• Issued: 05/13/2008
• Est. Priority Date: 05/16/2003
• Status: Expired due to Fees

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Chotkowski, Kimberly, Goldberg, Steven Jeffrey
• Primary Examiner(s): Feild; Joseph
• Assistant Examiner(s): DESIR, PIERRE LOUIS
• Application Number:
  US10/731,760
• Publication Number:
  US 20040229653A1
• Time in Patent Office: 1,617 Days
• Field of Search: 455/562.1, 455/561, 455/273, 455/63.4, 370/280, 342/383
• US Class Current: 455/562.1
• CPC Class Codes: H01Q 1/125 Means for positioning
• CPC Class Codes: H04B 7/0408 using two or more beams, i.e. beam diversity
• CPC Class Codes: H04W 16/24 Cell structures
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 52/42 in systems with time, space, frequency or polarisation diversity

Abstract

A method and system for coordinating the use of beam forming between two communicating entities in a wireless communication system is disclosed. The two entities may communicate control information regarding their respective use of beam forming. A correction factor for at least one entity is provided wherein said entity may reduce or withhold its beam adjustment in order to correct any error measured in the alignment of its beam with respect to the beam of the other entity with which it is communicating. Adjustment parameters for adjusting the beams are selected based on conditions surrounding the communication.

Claims

1. A method for coordinating the use of beam forming between a base station and a wireless transmit/receive unit (WTRU) wherein control information regarding the use of beam forming is not communicated between the base station and the WTRU, the method comprising the steps of:

selecting one of the base station and the WTRU for reduction of the amount in which the selected base station or WTRU will adjust its beam in response to misalignment between beams emanating from the base station and the WTRU;

measuring an error in the alignment of the beams emanating from the base station and the WTRU;

determining a correction factor based on the measured error;

selecting at least one adjustment parameter for adjusting the beam of the selected base station or WTRU; and

adjusting the beam of the selected base station or WTRU using the selected adjustment parameter in accordance with the correction factor, whereby the beams emanating from the base station and the WTRU are aligned with respect to each other.

2. The method of claim 1 wherein the base station is a WTRU.

3. The method of claim 1 wherein the at least one adjustment parameter is selected from the group consisting of boresight orientation, beam width, and power gain.

4. The method of claim 1 further comprising the step of:

repeating the measuring and adjusting steps until the error measured is below a predetermined value.

5. A method for coordinating the use of beam forming between a base station and a wireless transmit/receive unit (WTRU) wherein control information regarding the use of beam forming is communicated between the base station and the WTRU, the method comprising the steps of:

measuring an error in the alignment of beams emanating from the base station and the WTRU;

selecting at least one adjustment parameter for the base station;

identifying a first correction factor for the base station;

selecting at least one adjustment parameter for the WTRU;

identifying a second correction factor for the WTRU; and

adjusting the beam of the base station and the WTRU in an amount equal to the measured error multiplied by the correction factors in the base station and the WTRU such that the two beams emanating from the base station and the WTRU are aligned with respect to each other.

6. The method of claim 5 wherein the correction factor of the base station is zero thereby causing the base station to refrain from adjusting its beam.

7. The method of claim 5 wherein the base station is a WTRU.

8. The method of claim 5 wherein the correction factor of the WTRU is zero thereby causing the WTRU to refrain from adjusting its beam.

9. The method of claim 5 wherein the at least one adjustment parameter for the base station is selected from the group consisting of boresight orientation, beam width, and power gain.

10. The method of claim 5 wherein the at least one adjustment parameter for the WTRU is selected from the group consisting of boresight orientation, beam width, and power gain.

11. A method for coordinating the use of beam forming between a base station and a wireless transmit/receive unit (WTRU), the method comprising the steps of:

selecting a first correction factor and a first adjustment parameter for the base station and the WTRU for use in the azimuth dimension wherein the sum of the two first correction factors is equal to one;

selecting a second correction factor and a second adjustment parameter for the base station and the WTRU for use in the elevation dimension wherein the sum of the two second correction factors is equal to one;

measuring an error in the alignment of beams emanating from the base station and the WTRU in the azimuth dimension;

measuring an error in the alignment of beams emanating from the base station and the WTRU in the elevation dimension;

adjusting the beam of both the base station and the WTRU using the two first adjustment parameters according to the respective first correction factors in both the base station and the WTRU where an error is detected in the azimuth dimension; and

adjusting the beam of both the base station and the WTRU using the two second adjustment parameters according to their respective second correction factors where an error is detected in the elevation dimension, whereby the two beams emanating from the base station and the WTRU are aligned with respect to each other.

12. The method of claim 11 wherein the two first adjustment parameters are selected from the group consisting of boresight orientation, beam width, and power gain.

13. The method of claim 12 wherein the two first adjustment parameters are the same for both the base station and the WTRU.

14. The method of claim 12 wherein the two first adjustment parameters are different for both the base station and the WTRU.

15. The method of claim 11 wherein the two second adjustment parameters are selected from the group consisting of boresight orientation, beam width, and power gain.

16. The method of claim 15 wherein the two second adjustment parameters are the same for both the base station and the WTRU.

17. The method of claim 15 wherein the two second adjustment parameters are different for both the base station and the WTRU.

18. A method for coordinating the use of beam forming between a base station and a wireless transmit/receive unit (WTRU) wherein control information regarding the use of beam forming is communicated between the base station and the WTRU, the method comprising the steps of:

selecting a correction factor and at least one adjustment parameter for the base station and the WTRU;

measuring, at each base station and WTRU an error in the alignment of beams emanating from the base station and the WTRU; and

adjusting the beams using the selected adjustment parameters according to the correction factors in the base station and the WTRU and the measured error.

19. The method of claim 18 wherein the at least one adjustment parameter is selected from the group consisting of boresight orientation, beam width, and power gain.

20. The method of claim 18 wherein the at least one adjustment parameter is a plurality of adjustment parameters.

21. The method of claim 20 wherein the plurality of adjustment parameters are selected from the group consisting of boresight orientation, beam width, and power gain.

22. A wireless communication system wherein beams may be adjusted to enhance wireless communications between a base station and a wireless transmit/receive unit (WTRU) operating in the system, the wireless communication system comprising:

a plurality of base stations and WTRUs the base stations and WTRUs being capable of communicating using beam formed transmission and reception patterns and including a processor for measuring an error in the alignment of their own beam and the beam of another WTRU with which they are communicating and for determining a correction factor based on the measured error; and

wherein at least one of the base stations or WTRUs selects at least one adjustment parameter in accordance with the correction factor for adjusting its beam a fraction of the error measured in the alignment of its beam with respect to the beam of the other base station or WTRU.

23. The wireless communication system of claim 22 wherein the processor of the at least one base station or WTRU communicating is configured to adjust the beam of the at least one base station or WTRU in an amount equal to the fraction multiplied by the error measured.

24. The wireless communication system of claim 22 wherein the processor of the at least one base station or WTRU is configured to select at least one adjustment parameter for performing said adjustment.

25. The wireless communication system of claim 24 wherein the at least one adjustment parameter is selected from the group consisting of boresight orientation, beam width, and power gain.

26. A wireless transmit/receive unit (WTRU) configured to maintain alignment of its beam with the beam of another base station with which the WTRU is communicating, the WTRU comprising:

a first processor configured to measure an error in the alignment of a first beam emanating from the WTRU and a second beam emanating from the other base station;

wherein the first processor is further configured to determine a correction factor based on the measured error and to select at least one adjustment parameter for adjusting the first beam in accordance with the correction factor; and

a second processor configured to compute a first fraction and adjust the first beam using the at least one selected parameter in an amount equal to the first fraction multiplied by the error measured.

27. The WTRU of claim 26 further comprising:

a transmitter configured to transmit the fraction of the measured error that the WTRU will adjust its beam to the base station with which the WTRU is communicating.

28. The WTRU of claim 27 further comprising:

a receiver configured to receive, from the base station with which the WTRU is communicating, a second fraction with which the base station used to adjusts its beam; and

wherein when a second fraction is received, the second processor being configured to compute the first fraction by subtracting one minus the second fraction and adjusting the first beam in an amount equal to the first fraction multiplied by the error measured.

29. The WTRU of claim 28 wherein the base station with which the WTRU is communicating is another WTRU.

30. The WTRU of claim 26 wherein the at least one adjustment parameter is selected from the group consisting of boresight orientation, beam width, and power gain.