Use of linear prediction in detecting narrowband signals in colored noise

Use of the LPF in cascade with an FFT is demonstrated as a suboptimum realization of the optimum filter for maximization of instantaneous signal-to-rms noise power. Computer generated colored noise is used to compare the suboptimum filter with a conventional matched filter (designed for white noise only) in terms of output SNR for cases in which the signal and noise spectra overlap. Significant improvements in SNR are seen with the LPF - FFT cascade. The LPF coefficients are also used to form a non-causal pre-filter which is used in cascade with an FFT to process the same data and the results compared to the suboptimum filter results. Improvements in SNR are obtained, but thresholding the FFT output is seen to be more complicated.