Link16 Detection And Parameter Estimation Based On Improved Algorithm

Frequence Hopping(FH)communication is a common spread spectrum method in the spread spectrum communication system,which has many advantages such as difficult to intercept,difficult to decipher,great Anti-jamming performance and so on.It has been widely used in the field of communication reconnaissance and anti-jamming in military communication,among which the research of Link16 tactical data link has become the focus and difficulty of the research.At present,China has also started the construction of tactical data link.interception technology is relatively mature at present,but how to identify the intercepted signal type and process it remains to be studied.Therefore,it is very important to carry out in-depth research on the detection and parameter estimation of FH signal in the tactical data link of Link16.The main content of this paper includes the technical research of Link16,the fixed-hop recognition of the signal received by the receiver,the time-frequency analysis of the FH signal and the algorithm of signal parameter estimation.Link16 at first,this paper analyzed the technical characteristics of tactical data link,mainly aimed at the data link communication mode,encapsulation format,the signal characteristics are analyzed,and based on this,advances can be achieved by frequency hopping characteristic of signal,pulse cycle,signal characteristic parameters to determine whether a signal for Link16 signal,for each of these characteristics and the detection and parameter estimation algorithm is studied.Then this paper studies the commonly used time-frequency analysis techniques from linear and nonlinear aspects,and compares the analysis performance of different algorithms through simulation,and summarizes the advantages and disadvantages;Then the double-window spectrogram method is introduced,and the double-window spectrogram method is improved,and the joint analysis algorithm of double-window spectrogram method and Wigner distribution algorithm is proposed.The simulation results show that the algorithm effectively improves the performance of signal frequency estimation.At last,this paper studies the parameter estimation algorithm.Firstly,it introduces two classical parameter estimation algorithms of frequency hopping signal,and then introduces the parameter estimation algorithm based on image processing.The gray threshold method is applied to signal time-frequency graph processing.Then the morphology-based denoising algorithm and the signal segment splicing algorithm based on the connected domain marker are introduced to deal with the time-frequency cavity in the signal segment caused by the coupling of signal and noise due to the limitation of time-frequency analysis algorithm.On the basis of introducing the wiener filtering algorithm,the signal after the time-frequency analysis of time-frequency matrix corresponding signal time-frequency image processing,the MATLAB simulation,the algorithm effectively improves the signal parameter estimation performance,on the other hand,the processed image is in frequency estimation part of joined the matching algorithms,effectively reduced the frequency of the signal under low SNR estimation error.