Abstract: A new analysis of frequency hopped sequence based on time frequency presentation is proposed in the paper. The analysis method could plot the time frequency relation efficiently. It has higher resolution on the time frequency domain than short time Fourier transformation (STFT) or spectrogram(SG), and could reduce or completely remove the cross terms. The computation could take the recursive algorithm with lower computation complexity, so it could qualify for the frequency hopped communication system's analysis, track and measure. The computer simulations are presented demonstrating the capabilities of the analysis method based on time frequency presentation.

Key words: fr equency hop sequence, communication countermeasur es, time -frequency analysis, spectrogram, Winger-Ville distribution, short -time Four ier transformation