Hopping Signal Parameter Detection Methods Based On Time-frequency Distribution

Frequency-Hopping system, which has excellent anti-interference and anti-interception capacity, has caused great attention in the research field of military communication. For the opposition, how to get the parameter of the FH signal in a short time is essential to interference.A new analysis of FH sequence based on time-frequency presentation is proposed in this paper. Compare with short time Fourier transformation (STFT), Wigner-Vile distribution has better performance in the field of FH signal estimation. In addition, the smooth pseudo Wigner-Vile distribution, instead of the direct WVD, could reduce or remove the cross-terms interfere.In the lower SNR situation, the method is biased when the peak of the SPWVD is used to estimate the signal's instantaneous frequency. By time-frequency peak filtering repeatedly, the additive noise and the bias of estimation value would be reduced.The smooth pseudo WVD window length has a great effect on the estimate performance. How to choose the window length and shape is also considered in this paper.