Wavelet-based model matching for FM denoising

A transform-model based approach for suppressing noise in frequency modulated (FM) signals is presented. This approach is based on a model of the expected output of a wavelet filter bank in response to a noise-free FM signal. Resolving the discrepancy between filter bank output in response to a noisy FM signal and the expected output given by the model provides the mechanism for noise suppression. Specifically, a stationary phase approximation to the Morlet wavelet transform is used to form the model. The approach is shown to perform favorably on a numerical example when compared to both simple lowpass filtering (linear) and wavelet thresholding (non-linear) denoising techniques.