Patent ID: 9077409
Filing Date: 2015-07-07
Classification: H03F,H04B,H04L

Abstract:
1. A communication signal processing system, comprising: a peak-to-average ratio (PAPR) reducer that reduces a peak-to-average ratio (PAPR) of an input signal to generate a PAPR reduced signal, wherein generation of a clipping noise signal is occurred in the PAPR reducer; a clipping noise processing system that splits, in a time domain, the clipping noise signal into an in-band clipping signal and an out-of-band clipping signal, and generates an equivalent clipping noise signal that is defined as a weighted sum of a weighted in-band clipping signal and a weighted out-of-band clipping signal, wherein the weighted in-band clipping signal is generated by weighting the in-band clipping signal in a time domain with a first weight, and the weighted out-of-band clipping signal is generated by weighting the out-of-band clipping signal in time domain with a second weight; a reduced noise signal generator that generate a reduced clipping noise signal that has a further reduced peak-to-average power level using the equivalent clipping noise signal ε*CL(n); a predistorter that distorts the PAPR reduced signal and the reduced clipping noise signal to generate a distorted signal and a distorted clipping noise signal by applying an approximated inverse of an amplification function on the PAPR reduced signal and the reduced clipping noise signal, respectively, wherein the approximated inverse of an amplification function is defined by a polynomial with predistorter coefficients; an amplifier input signal generator that generates a difference between the distorted signal and the distorted clipping noise signal as a high power amplifier (HPA) input signal; an amplifier that amplifies the high power amplifier (HPA) input signal with a gain G to generate an output signal; and a reference signal generator that generates a reference signal that has a further reduced peak-to-average power level than the PAPR reduced signal using the PAPR reduced signal and the equivalent clipping noise signal or using a divided output signal, wherein the predistorter compares the reference signal and the divided output signal to determine the predistorter coefficients.