SIGNAL PEAK-TO-AVERAGE POWER RATIO (PAR) REDUCTION

• US 20140341315A1
• Filed: 05/14/2013
• Published: 11/20/2014
• Est. Priority Date: 05/14/2013
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel IP Corporation (Intel Corporation)
• Inventors: COVA, Armando
• Granted Patent: US 9,154,168 B2
• Time in Patent Office: Days
• US Class Current: 375/296
• CPC Class Codes: H04B 1/0475 with means for limiting noise, interference or distortion H04B1/0483 takes precedence
• CPC Class Codes: H04L 27/2626 Arrangements specific to the transmitter only
• CPC Class Codes: H04L 27/3411 reducing the peak to average power ratio or the mean power of the constellation; Arrangements for increasing the shape gain of a signal set

Abstract

A method of reducing a peak to average power ratio (PAR) of a signal may include generating an in-band error signal indicating in-band distortion of a compressed signal and generating an out-of-band error signal indicating out-of-band distortion of the compressed signal. The method may further include applying an in-band gain to the in-band error signal to generate an adjusted in-band error signal and applying an out-of-band gain to the out-of-band error signal to generate an adjusted out-of-band error signal. The method may also include combining the compressed signal with the adjusted in-band error signal and the adjusted out-of-band error signal to generate an output signal. The compressed signal may be combined with the adjusted error signals, and the in-band gain and the out-of-band gain may be based on the output signal such that distortion of the output signal is reduced with respect to distortion of the compressed signal.

Claims

1. A method of reducing a peak to average power ratio (PAR) of a signal comprising:

generating an in-band error signal indicating in-band distortion of a compressed signal with respect to an input signal from which the compressed signal is generated;

generating an out-of-band error signal indicating out-of-band distortion of the compressed signal with respect to the input signal;

applying an in-band gain to the in-band error signal to generate an adjusted in-band error signal;

applying an out-of-band gain to the out-of-band error signal to generate an adjusted out-of-band error signal; and

combining the compressed signal with the adjusted in-band error signal and the adjusted out-of-band error signal to generate an output signal, the compressed signal being combined with the adjusted in-band error signal and the adjusted out-of-band error signal, and the in-band gain and the out-of-band gain being based on the output signal such that distortion of the output signal is reduced with respect to distortion of the compressed signal.

2. The method of claim 1, further comprising adjusting the in-band gain based on an in-band distortion target.

3. The method of claim 1, further comprising adjusting the out-of-band gain based on an out-of-band distortion target.

4. The method of claim 1, further comprising adjusting the in-band gain, the out-of-band gain, or both the in-band gain and the out-of-band gain based on an optimization scheme.

5. The method of claim 1, further comprising clipping an amplitude of the input signal to generate the compressed signal.

6. The method of claim 1, further comprising determining in-band distortion of the output signal based on an error vector magnitude (EVM) of the output signal with respect to the input signal and adjusting the in-band gain, the out-of-band gain, or both the in-band gain and the out-of-band gain based on the EVM.

7. The method of claim 1, further comprising determining out-of-band distortion of the output signal based on an adjacent channel leakage ratio (ACLR) of the output signal and adjusting the in-band gain, the out-of-band gain, or both the in-band gain and the out-of-band gain based on the ACLR.

8. The method of claim 1, further comprising:

comparing the input signal with the compressed signal to generate an error signal indicating distortion between the input signal and the compressed signal;

filtering the error signal based on an in-band frequency range to generate the in-band error signal; and

filtering the error signal based on an out-of-band frequency range to generate the out-of-band error signal.

9. The method of claim 8, further comprising filtering the error signal with a low-pass filter to generate the in-band error signal.

10. The method of claim 8, further comprising filtering the error signal with a high-pass filter to generate the out-of-band error signal.

11. A system of reducing a peak-to-average power ratio (PAR) of a signal comprising:

an error detection module configured to generate an in-band error signal indicating in-band distortion of a compressed signal with respect to an input signal from which the compressed signal is generated, the error detection module also being configured to generate an out-of-band error signal indicating out-of-band distortion of the compressed signal with respect to the input signal;

an in-band gain unit configured to apply an in-band gain to the in-band error signal to generate an adjusted in-band error signal;

an out-of-band gain unit configured to apply an out-of-band gain to the out-of-band error signal to generate an adjusted out-of-band error signal; and

a combining module configured to combine the compressed signal with the adjusted in-band error signal and the adjusted out-of-band error signal to generate an output signal, the combining module configured to combine the compressed signal with the adjusted in-band error signal and the adjusted out-of-band error signal, the in-band gain unit configured to apply the in-band gain based on the output signal, and the out-of-band gain unit configured to apply the out-of-band gain based on the output signal such that distortion of the output signal is reduced with respect to distortion of the compressed signal.

12. The system of claim 11, further comprising an adaptation module configured to adjust the in-band gain based on an in-band distortion target.

13. The system of claim 11, further comprising an adaptation module configured to adjust the out-of-band gain based on an out-of-band distortion target.

14. The system of claim 11, further comprising an adaptation module configured to adjust the in-band gain based on an optimization scheme.

15. The system of claim 11, further comprising an adaptation module configured to adjust the out-of-band gain based on an optimization scheme.

16. The system of claim 11, further comprising a compressing module configured to clip an amplitude of the input signal to generate the compressed signal.

17. The system of claim 11, further comprising an adaptation module configured to determine in-band distortion of the output signal based on an error vector magnitude (EVM) of the output signal with respect to the input signal and configured to adjust the in-band gain, the out-of-band gain, or both the in-band gain and the out-of-band gain based on the EVM.

18. The system of claim 11, further comprising an adaptation module configured to determine out-of-band distortion of the output signal based on an adjacent channel leakage ratio (ACLR) of the output signal and configured to adjust the in-band gain, the out-of-band gain, or both the in-band gain and the out-of-band gain based on the ACLR.

19. The system of claim 11, wherein the error detection module comprises:

a comparator configured to compare the input signal with the compressed signal to generate an error signal indicating distortion between the input signal and the compressed signal;

an in-band filter configured to filter the error signal based on an in-band frequency range to generate the in-band error signal; and

an out-of-band filter configured to filter the error signal based on an out-of-band frequency range to generate the out-of-band error signal.

20. The system of claim 19, wherein the in-band filter includes a low-pass filter and the out-of-band filter includes a high-pass filter.