CDMA signal transmission control

• US 6,687,238 B1
• Filed: 03/10/1999
• Issued: 02/03/2004
• Est. Priority Date: 03/10/1999
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Soong, Anthony C. K., Harms, Brian K., Weaver, Lindsay A. Jr., Pressley, Todd A., Flowers, Larry D., Funk, Thomas J., Schwartz, Bruce S., Night, Robin
• Primary Examiner(s): Yao, Kwang Bin
• Application Number:
  US09/265,204
• Time in Patent Office: 1,791 Days
• Field of Search: 370/320, 370/328, 370/335, 370/342, 370/441, 370/488, 370/497, 375/130, 375/140, 375/144, 375/295, 375/296, 375/297
• US Class Current: 370/335
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04B 2201/70706 with means for reducing the peak-to-average power ratio
• CPC Class Codes: H04W 52/246 where the output power of a terminal is based on a path parameter calculated in said terminal
• CPC Class Codes: H04W 52/34 TPC management, i.e. sharing limited amount of power among users or channels or data types, e.g. cell loading
• CPC Class Codes: H04W 52/52 using AGC [Automatic Gain Control] circuits or amplifiers

Abstract

The invention is a CDMA transmission control technology that includes various combinations of the following functionality: decresting, in-band to out-of-band ratio (RIO), power control, and spectral shaping. Decresting reduces peaks in the CDMA signal. RIO generates a ratio based on the signal strength of in-band versus out-of-band portions of the CDMA signal. Power control adjusts the gain of the CDMA signal based on quadrature signal calculations. Spectral shaping attenuates in-band portions of the CDMA signal adjacent to the corner frequencies. The CDMA transmission control technology can be implemented in a CDMA base station to extend range and capacity.

Claims

1. A device for processing a Code Division Multiple Access (CDMA) signal, the device comprising:

decresting logic operational to reduce peaks exceeding a threshold in the CDMA signal; and

spectral shaping logic operational to attenuate in-band signal power near corner frequencies of the CDMA signal, wherein said in-band signal power is contained within bandwidth defined by said corner frequencies around a center frequency.

2. The device of claim 1 wherein the decresting logic is further operational to generate a digital correction signal in response to the peaks and to combine the digital correction signal with a digital version of the CDMA signal.

3. The device of claim 2 wherein the decresting logic is further operational to generate the correction signal by processing polar coordinate representations of quadrature components of the CDMA signal.

4. The device of claim 1 wherein the spectral shaping logic is further operational to attenuate the in-band frequencies adjacent to a first corner frequency and adjacent to a second corner frequency, wherein the corner frequencies define a bandwidth for the CDMA signal.

5. The device of claim 1 further comprising ratio logic operational to automatically generate a ratio of strength of at least a portion of in-band components in the CDMA signal to at least a portion of out-of-band components in the CDMA signal.

6. The device of claim 5 wherein the ratio logic is further operational to generate a metric signal to limit transmit power based on the ratio.

7. The device of claim 5 wherein the ratio logic is further operational to generate a metric signal indicating excess forward link capacity based on the ratio.

8. The device of claim 5 wherein the ratio logic is further operational to set the threshold based on the ratio.

9. The device of claim 5 further comprising power control logic operational to compare a power value calculated from quadrature components of the CDMA signal to a transmit power of the CDMA signal, and to automatically adjust a gain of the CDMA signal based on the comparison.

10. The device of claim 9 wherein the decresting logic is further operational to calculate the power value.

11. The device of claim 9 further comprising a power monitor operational to monitor the transmit power of the CDMA signal.

12. The device of claim 9 further comprising a cell site modem operational to generate the CDMA signal.

13. The device of claim 9 further comprising a digital-to-analog converter operational to convert the CDMA signal from digital to analog.

14. The device of claim 9 further comprising a low-pass filter operational to attenuate out-of-band noise in the CDMA signal.

15. The device of claim 9 further comprising an up-converter operational to modulate the CDMA signal to a radio frequency.

16. The device of claim 9 further comprising a power amplifier operational to amplify the CDMA signal.

17. The device of claim 9 further comprising an antenna operational to transmit the CDMA signal.

18. A device for processing a Code Division Multiple Access (CDMA) signal, the device comprising:

decresting logic operational to reduce peaks exceeding a threshold in the CDMA signal; and

ratio logic operational to automatically generate a ratio of strength of at least a portion of in-band components in the CDMA signal to at least a portion of out-of-band components in the CDMA signal, wherein said threshold corresponds to said ratio.

19. The device of claim 18 wherein the decresting logic is further operational to generate a digital correction signal in response to the peaks and to combine the digital correction signal with a digital version of the CDMA signal.

20. The device of claim 19 wherein the decresting logic is further operational to generate the correction signal by processing polar,coordinate representations of quadrature components of the CDMA signal.

21. The device of claim 18 wherein the ratio logic is further operational to generate a metric signal to limit transmit power based on the ratio.

22. The device of claim 18 wherein the ratio logic is further operational to generate a metric signal indicating excess forward link capacity based on the ratio.

23. The device of claim 18 wherein the ratio logic is further operational to set the threshold based on the ratio.

24. The device of claim 18 further comprising a cell site modem operational to generate the CDMA signal.

25. The device of claim 18 further comprising a digital-to-analog converter operational to convert the CDMA signal from digital to analog.

26. The device of claim 18 further comprising a low-pass filter operational to attenuate out-of-band noise in the CDMA signal.

27. The device of claim 18 further comprising an up-converter operational to modulate the CDMA signal to a radio frequency.

28. The device of claim 18 further comprising a power amplifier operational to amplify the CDMA signal.

29. The device of claim 18 further comprising an antenna operational to transmit the CDMA signal.

30. A device for processing a Code Division Multiple Access (CDMA) signal, the device comprising:

decresting logic operational to provide quadrature components of the CDMA signal and reduce peaks exceeding a threshold in the CDMA signal; and

power control logic operational to compare a power value calculated from said quadrature components to a transmit power of the CDMA signal, and to automatically adjust a gain of the CDMA signal based on the comparison.

31. The device of claim 30 wherein the decresting logic is further operational to generate a digital correction signal in response to the peaks and to combine the digital correction signal with a digital version of the CDMA signal.

32. The device of claim 31 wherein the decresting logic is further operational to generate the correction signal by processing polar coordinate representations of quadrature components of the CDMA signal.

33. The device of claim 30 further comprising spectral shaping logic operational to attenuate in-band frequencies of the CDMA signal.

34. The device of claim 33 wherein the spectral shaping logic is further operational to attenuate the in-band frequencies adjacent to a first corner frequency and adjacent to a second corner frequency, wherein the corner frequencies define a bandwidth for the CDMA signal.

35. The device of claim 30 wherein the decresting logic is further operational to calculate the power value.

36. The device of claim 30 further comprising a power monitor operational to monitor the transmit power of the CDMA signal.

37. The device of claim 30 further comprising a cell site modem operational to generate the CDMA signal.

38. The device of claim 30 further comprising a digital-to-analog converter operational to convert the CDMA signal from digital to analog.

39. The device of claim 30 further comprising a low-pass filter operational to attenuate out-of-band noise in the CDMA signal.

40. The device of claim 30 further comprising an up-converter operational to modulate the CDMA signal to a radio frequency.

41. The device of claim 30 further comprising a power amplifier operational to amplify the CDMA signal.

42. The device of claim 30 further comprising an antenna operational to transmit the CDMA signal.