Hop Duration Estimation Of Non-cooperative Frequency-hopping Signals

Frequency-Hopping (FH) communication has many advantages of high anti-jamming capability, low intercept probability, secrecy and easy networking etc., so it has been widely used in military and civilian field. Meanwhile, FH communication makes electronic countermeasure and communication reconnaissance facing serious challenges. How to extract the characteristic parameters of the intercepted FH signal is the key to obtain useful information and jamming. Hop duration is a very important parameter, in order to intercept FH signal and reconstruct timing sequence, all need estimate it accurately.In this dissertation, my main work is to estimate hop duration of FH signal. Hop duration estimation algorithm based on time-frequency analysis and FH signal in the mixed signals is studied respectively.For hop duration estimation based on time-frequency analysis. Then different algorithms based on Time-Frequency analysis, which don't need to know the prior knowledge of the FH signals, are carried out in this dissertation, including STFT, WVD, PWVD, SPWVD, Morlet Wavelet. According to the hop rate of FH signal, algorithms in public papers are studied and simulated, their performance are analysed. Meanwhile, the new hop duration estimation algorithms of low-speed and high-speed FH signal are proposed, and the simulation and performance analysis are presented.For hop duration estimation of FH signal in the mixed signals, algorithms in public papers are studied. A method, which eliminates the fixed frequency signals in the mixed signals, is proposed and simulated. The hop duration of the FH signal is estimated, the estimated step of hop duration is summarized.Finally, the prospect of the hop duration estimation of FH signals and communication countermeasure technologies are presented.Some further developing way which might worth researching is given.