An efficient echo cancelling scheme based on Nth-order SSC algorithm for nonlinear frequency modulated signal

In this paper, a cancelling scheme for the nonlinear frequency modulated (NLFM) signal (Taylor window and Tangent-based) is proposed with assistance of the Nth-order SSC (Spectrum Spread and Compression) algorithm. The explicit expressions of echo cancelling wave are derived for the Nth-order SSC algorithm. The received NLFM signal is expanded N times and then compressed N-1 times in frequency domain using its delayed version to generate jamming signal. According to the RCS (Radar Cross Section) characteristic of target, amplitude and phase modulation of the jamming signal are made to acquire the cancelling signal, which has the same amplitude, frequency as the echo signal but with the opposite phase. Simulation results show that the cancelling signal could reduce the target gain when the time delay and the phase error are relatively large.