Research On Signal Splicing In Blind Receiving System Of Frequency Hopping

Frequency hopping(FH)communication technology has been widely used in the field of tactical communication countermeasures with its excellent anti-jamming performance.In non-cooperative communication,the blind receiving technology of FH can detect and decrypt the intercepted communication signal without any prior information,and can interfere the enemy communication according to the reconnaissance result.So,the blind receiving technology of FH is the focus of research in the field of communication anti-jamming at present.In the blind reception system of frequency hopping communication,it is the key point to implement frequency hopping signal de-hopping and splicing with the data provided by signal detection and parameter estimation.The research contents of this paper aiming at the blind receiving technology of FH communication mainly include: the research of signal de-hopping and splicing in non-cooperative frequency hopping communication;the research of frequency hopping signal de-hopping and splicing in the environment of parameter estimation error and the research of the global performance of FH blind receiving system.In the part of signal de-hopping and splicing in non-cooperative frequency hopping communication,the front-end signal processing technology and two kinds of non-coherent demodulation methods in FH receiving system are analyzed,and then the de-hopping and splicing of FH signals with different modulation modes is studied.In the state of hopping synchronization,the FH signals of four modulation modes are de-hopped and demodulated,and the performance of signal de-hopping with different modulation modes is analyzed by comparing the bit error rate obtained from the simulation experiments.In the part of FH signal de-hopping in the environment of parameter estimation error,the effect of frequency estimation error and time hopping estimation error on the performance of FH signal de-hopping is studied.When there are errors in frequency estimation and time hopping estimation,the FH signals with different modulation modes are de-hopped,and this paper analyzes the precision requirement of parameter estimation in order to realize effective de-hopping and demodulation.Then in order to solve the problem that the output signal has frequency difference after de-hopping,in this paper,a frequency difference analysis and frequency adjustment method based on modern power spectrum estimation is proposed to reduce the frequency difference in de-hopped signals is studied.Finally,the effect of interference signals on the performance of de-hopping and splicing is studied.By means of de-hopping and demodulation in different interference environment,the precision requirement of front-end signal processing is analyzed in order to realize effective de-hopping and splicing.The research on whole performance of the blind receiving system of FH communication,in this paper,the signal detection,parameter estimation,de-hopping and splicing,modulation identification and demodulation in the blind receiving technology of FH are connected and analyzed as a whole and frequency difference analysis and frequency adjustment are added.Through simulation analysis of the whole structure,the error rate of the experimental results verifies that the blind receiver system of FH works well.