Patent ID: 6868114

Claim:
A method of performing frequency domain excision on a received signal including a desired wideband signal component, comprising: applying a window function to each of overlapped blocks of samples of the received signal to generate windowed blocks of signal samples, the window function having a central maximum and tapering to zero at beginning and ending points; performing a predetermined transform function on each of the windowed blocks of signal samples to generate corresponding blocks of frequency-domain coefficients; for each block of frequency-domain coefficients: (1) morphologically filtering the coefficients to generate a threshold function representing an estimate of the spectrum of the desired wideband signal component, the threshold function including a plurality of threshold values corresponding to the coefficients; and (ii) applying a gain function to each coefficient to generate an excised block of coefficients, the gain function for each coefficient having a fixed-gain region for input values less than the corresponding threshold value from the threshold function, an excision region for input values greater than a predetermined multiple of the corresponding threshold value, and a soft limiting region between the fixed-gain region and the excision region; performing the inverse of the transform function on the excised blocks of coefficients to generate excised blocks of signal samples; and applying an overlap-eliminating central portion of the inverse of the window function to each excised block of signal samples.