| 摘要 |
A distortion suppressor and method for suppressing distortion that performs processing in the time domain to suppress partial time distortion of received signals, and/or the frequency domain to suppress partial band distortion of the received signals. For time domain suppression, the received signals are sampled and sample amplitudes are sorted. Based on the sorted samples, the receiver searches for two levels, SL and SM, representing clipping and removal thresholds. Any samples having amplitudes above SL are removed (zeroed), samples having amplitudes below SL are left alone, and samples having amplitudes between SL and SM are clipped to SL. The processor searches for optimum SL and SM values to maximize the signal to noise ratio of the received signals. For frequency domain suppression, the received signals are processed by a Fourier transform (FFT) processor. The spectrum of output signals from the FFT processor is sampled in a manner similar to the time domain suppression. The sample amplitudes are sorted, and the clipping and removal thresholds, SL and SM, are determined such that the output signal to noise ratio is maximized. Samples having amplitudes above SM are zeroed, and samples having amplitudes between SL and SM are clipped to SL. The resulting signal has a maximum signal to noise ratio, that maximizes receiver performance. Clipping and removal thresholds SL, SM are set with reference to the sorted amplitude profile, which determines two optimum clipping and removal threshold levels for the frequency distribution. Finally, the signals levels are clipped as stated above to maximize the suppression of interference and noise while achieving minimum distortion of the signals.
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