Generalized Fractional Matched Filtering and its Applications

Abstract

Time domain matched filtering is a classic method used in radar and sonar applications to maximize signal to noise ratio (SNR) gain, estimate time delay, and improve range resolution. Fractional Fourier transform, and fractional Fourier domain matched filtering are used extensively to overcome the drawbacks of time domain matched filtering and are shown to have improved performance for a linear chirp. This paper presents a generalized fractional matched filtering (GFMF) for estimating higher order chirp parameters with known time delay. It is shown to provide SNR gain equivalent to time domain matched filtering. As an application of GFMF, a novel method to minimize SNR gain degradation due to the range-Doppler coupling effect of quadratic chirps is presented. For a higher order chirp with unknown time delay, another method using generalized fractional envelope correlator (GFEC) is proposed, which performs joint estimation of time delay and higher order chirp parameters using a double quadratic chirp.