A high resolution spectral estimator for noisy broadband FM signals-with application to multipath radio

The discrete Wigner distribution (DWD), an FFT (fast Fourier transform)-based spectral estimator, is applied to estimate the broadband FM signals. The effective dispersion index of the DWD kernel is determined to be significantly reduced over that of conventional moving window estimators. The two multipath radio conditions for which the DWD estimator produces poor results, multicomponent signals and low signal-to-noise ratios, are addressed in terms of the smoothed-DWD where effectively a windowed, filtered version of the DWD is produced. Window and filter selections for maximum signal concentration are determined and experimentally tested