A fast time delay estimator of cubic phase signal based on simplified fractional fourier transform

The time delay estimation between two signals has always been an important issue. In this paper, we propose a new fast time delay estimation method of cubic phase signal based on Simplified Fractional Fourier transform (SFFT). First, 2-order instantaneous cross terms is introduced to transform cubic phase signal to chirp signal form. Then time delay is evaluated in the Simplified Fractional Fourier domain by measuring the time differential of two peak values in Fractional spectrum. Simulation shows better and faster estimation performance compared to GCC method at relatively low SNR.