Radiated power control for a multi-antenna transmission

• US 7,747,271 B2
• Filed: 03/02/2005
• Issued: 06/29/2010
• Est. Priority Date: 03/02/2005
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Walton, Jay Rodney, Zhang, Xiangdong
• Primary Examiner(s): Benson; Walter
• Assistant Examiner(s): Luo; David S
• Application Number:
  US11/070,734
• Publication Number:
  US 20060199604A1
• Time in Patent Office: 1,945 Days
• Field of Search: 455/63.4, 455/39, 455/500, 455/507, 455/517, 455/522, 455/127.1, 455/91, 455/68, 455/69
• US Class Current: 455/522
• CPC Class Codes: H04W 52/42 in systems with time, space, frequency or polarisation diversity

Abstract

To meet a radiated power limit, a transmitting station determines a synthesized antenna pattern based on steering vectors used for spatial processing and estimates an array gain based on the synthesized antenna pattern. Different spatial processing modes (e.g., eigensteering and spatial spreading) result in different synthesized antenna patterns. The array gain may be estimated based on the spatial processing mode used for the data transmission and applicable parameters (e.g., eigenvalues) for that mode. An element gain for each antenna used for data transmission may also be estimated. The transmitting station then limits the transmit power for the data transmission based on the array gain, the element gain, and the radiated power limit, which may be an effective isotropic radiated power (EIRP) limit imposed by a regulatory agency.

Claims

1. A method of controlling radiated power for a data transmission utilizing spatial processing, comprising:

estimating an array gain based on a synthesized antenna pattern for the data transmission and a spatial processing mode; and

limiting the transmit power for the data transmission based on the array gain and a radiated power limit.

2. The method of claim 1, further comprising:

determining the synthesized antenna pattern based on at least one steering vector used for spatial processing for the data transmission.

3. The method of claim 1, wherein the estimating the array gain based on the synthesized antenna pattern comprises

determining an eigenvalue for a spatial channel used for the data transmission, and

deriving the array gain based on the eigenvalue.

4. The method of claim 1, wherein the estimating the array gain based on the synthesized antenna pattern comprises

determining a plurality of eigenvalues for a plurality of spatial channels used for the data transmission, and

deriving the array gain based on the plurality of eigenvalues.

5. The method of claim 1, wherein the estimating the array gain based on the synthesized antenna pattern comprises

determining a plurality of eigenvalues for a plurality of frequency subbands of at least one wideband spatial channel-used for the data transmission, and

deriving the array gain based on the plurality of eigenvalues.

6. The method of claim 1, wherein the estimating the array gain based on the synthesized antenna pattern comprises

determining a plurality of eigenvalues for a plurality of frequency subbands of a wideband spatial channel used for the data transmission, and

deriving the array gain based on a largest eigenvalue among the plurality of eigenvalues.

7. The method of claim 1, wherein the estimating the array gain based on the synthesized antenna pattern comprises

determining a plurality of eigenvalues for a plurality of frequency subbands of a wideband spatial channel used for the data transmission, and

deriving the array gain based on an average of the plurality of eigenvalues.

8. The method of claim 1, wherein the estimating the array gain based on the synthesized antenna pattern comprises

setting the array gain to a predetermined value if the synthesized antenna pattern is a spatially spread synthesized antenna pattern.

9. The method of claim 1, wherein the estimating the array gain based on the synthesized antenna pattern comprises

determining a spatial processing mode used for the data transmission, and

setting the array gain to a predetermined value for the spatial processing mode used for the data transmission.

10. The method of claim 1, further comprising:

estimating an element gain for each of a plurality of antennas used for the data transmission, and wherein the transmit power for the data transmission is limited further based on the element gain.

11. The method of claim 1, wherein the radiated power limit is an effective isotropic radiated power (EIRP) limit.

12. An apparatus for data transmission utilizing spatial processing in a wireless communication network, comprising:

a controller to estimate an array gain based on a synthesized antenna pattern for a data transmission and a spatial processing mode; and

a control unit to limit transmit power for the data transmission based on the array gain and a radiated power limit.

13. The apparatus of claim 12, wherein the controller determines the synthesized antenna pattern based on at least one steering vector used for spatial processing for the data transmission.

14. The apparatus of claim 12, wherein the controller determines at least one eigenvalue for at least one spatial channel used for the data transmission and derives the array gain based on the at least one eigenvalue.

15. The apparatus of claim 12, wherein the controller determines a plurality of eigenvalues for a plurality of frequency subbands of at least one wideband spatial channel used for the data transmission and derives the array gain based on the plurality of eigenvalues.

16. The apparatus of claim 12, wherein the controller sets the array gain to a predetermined value if the synthesized antenna pattern is a spatially spread synthesized antenna pattern.

17. The apparatus of claim 12, wherein the controller estimates an element gain for each of a plurality of antennas used for data transmission, and wherein the processor limits the transmit power for the data transmission further based on the element gain.

18. An apparatus for data transmission utilizing spatial processing in a wireless communication network, comprising:

means for estimating an array gain based on a synthesized antenna pattern for a data transmission and a spatial processing mode; and

means for limiting transmit power for the data transmission based on the array gain and a radiated power limit.

19. The apparatus of claim 18, further comprising:

means for determining the synthesized antenna pattern based on at least one steering vector used for spatial processing for the data transmission.

20. The apparatus of claim 18, wherein the means for estimating the array gain based on the synthesized antenna pattern comprises

means for determining at least one eigenvalue for at least one spatial channel used for the data transmission, and

means for deriving the array gain based on the at least one eigenvalue.

21. The apparatus of claim 18, wherein the means for estimating the array gain based on the synthesized antenna pattern comprises

means for determining a plurality of eigenvalues for a plurality of frequency subbands of at least one wideband spatial channel used for the data transmission, and

means for deriving the array gain based on the plurality of eigenvalues.

22. The apparatus of claim 18, wherein the means for estimating the array gain based on the synthesized antenna pattern comprises

means for setting the array gain to a predetermined value if the synthesized antenna pattern is a spatially spread synthesized antenna pattern.

23. The apparatus of claim 18, further comprising:

means for estimating an element gain for each of a plurality of antennas used for data transmission, and wherein the transmit power for the data transmission is limited further based on the element gain.

24. A computer-program product for controlling radiated power for a data transmission utilizing spatial processing, the computer-program product comprising a non-transitory computer readable medium having a set of instructions stored thereon, the set of instructions being executable by one or more processors and the set of instructions comprising:

instructions for estimating an array gain based on a synthesized antenna pattern for the data transmission and a spatial processing mode; and

instructions for limiting the transmit power for the data transmission based on the array gain and a radiated power limit.

25. The computer-program product of claim 24, wherein the set of instructions further comprises:

instructions for determining the synthesized antenna pattern based on at least one steering vector used for spatial processing for the data transmission.

26. The computer-program product of claim 24, wherein the instructions for estimating the array gain based on the synthesized antenna pattern comprise

instructions for determining an eigenvalue for a spatial channel used for the data transmission, and

instructions for deriving the array gain based on the eigenvalue.

27. The computer-program product of claim 24, wherein the instructions for estimating the array gain based on the synthesized antenna pattern comprise

instructions for determining a plurality of eigenvalues for a plurality of spatial channels used for the data transmission, and

instructions for deriving the array gain based on the plurality of eigenvalues.

28. The computer-program product of claim 24, wherein the instructions for estimating the array gain based on the synthesized antenna pattern comprise

instructions for determining a plurality of eigenvalues for a plurality of frequency subbands of at least one wideband spatial channel-used for the data transmission, and

instructions for deriving the array gain based on the plurality of eigenvalues.

29. The computer-program product of claim 24, wherein the instructions for estimating the array gain based on the synthesized antenna pattern comprise

instructions for determining a plurality of eigenvalues for a plurality of frequency subbands of a wideband spatial channel used for the data transmission, and

instructions for deriving the array gain based on a largest eigenvalue among the plurality of eigenvalues.

30. The computer-program product of claim 24, wherein the instructions for estimating the array gain based on the synthesized antenna pattern comprise

instructions for determining a plurality of eigenvalues for a plurality of frequency subbands of a wideband spatial channel used for the data transmission, and

instructions for deriving the array gain based on an average of the plurality of eigenvalues.

31. The computer-program product of claim 24, wherein the instructions for estimating the array gain based on the synthesized antenna pattern comprise

instructions for setting the array gain to a predetermined value if the synthesized antenna pattern is a spatially spread synthesized antenna pattern.

32. The computer-program product of claim 24, wherein the instructions for estimating the array gain based on the synthesized antenna pattern comprise

instructions for determining a spatial processing mode used for the data transmission, and

instructions for setting the array gain to a predetermined value for the spatial processing mode used for the data transmission.

33. The computer-program product of claim 24, wherein the set of instructions further comprise:

instructions for estimating an element gain for each of a plurality of antennas used for the data transmission, and wherein the transmit power for the data transmission is limited further based on the element gain.

34. The computer-program product of claim 24, wherein the radiated power limit is an effective isotropic radiated power (EIRP) limit.