Hop Rate Estimation of Hybrid DS/FH Spread Spectrum Signals Based on a Channelized Spectral Enhancement Strategy
基于信道化谱增强的混合DS/FH扩频信号跳速估计

This paper addresses new hop rate estimation schemes for hybrid DS/FH_BPSK signals which employ a novel channelized spectral enhancement preprocessor and time-frequency analysis. Good performance is achieved by following three stages. Firstly, a nonlinear process is used to produce the reference signal which has the same hop rate as the original signal and its frequencies could be estimated by the cyclic spectrum. Then a novel Externally-Linear-Internally-Nonlinear(ELIN) channelized spectral enhancement system is employed to realize interference-suppression and enhance noisy signal without losing detail information. Finally, based on the reliable signal enhancement results, SPWVD(Smooth-Pseudo-Wigner-Ville Distribution) is used to estimate the hop rate of the hybrid DS/FH spread spectrum signal. Since no prior information of signals are needed, the proposed method is easy to implement for the reconnaissance receiver. The simulation results show that the proposed method can operate effectively even under low SNR conditions.