High Speed Frequency-hopping Signal Interception Technology And Realization

Frequency-hopping communication is widely used in military field because of its outstanding anti-interception and anti-jamming capability.The development of frequency-hopping communication is moving towards high speed and ultra-wideband directions.Therefore,high-speed frequency-hopping signal detection technology has become a hot topic at home and abroad.This paper focuses on the real-time detection,analysis and demodulation of high-speed frequency-hopping signal.It includes the following five aspects.1.The basic theoretical knowledge and composition of frequency-hopping communication system are introduced,major indicators and characteristics are analyzed,both of which can provide important references for the research of high-speed frequency-hopping signal detection technology.2.The technique of frequency-hopping signal detection is studied.Usual methods of detecting frequency-hopping signal are analyzed and compared from time domain detection aspect,frequency domain detection aspect and time-frequency analysis aspect respectively.The time domain detection mainly includes techniques like energy detection,double sliding window,high-order cumulants and short-time self-correlation.The frequency domain detection mainly includes techniques like power-law detection and power spectrum detection.The time-frequency detection mainly includes techniques such as wavelet,WVD and short-time Fourier transform.Through analysis and comparison,real-time detection is realized by feedback detection which is combined with frequency domain and time domain.3.The technique of estimating high speed frequency-hopping signal modulation parameter is studied.The principle of SDPSK signal generation is discussed and characteristics of SDPSK signal are analyzed.Through comparison,parameter estimation method has been decided.4.The demodulation of high speed frequency-hopping signal is studied.This paper focuses on the carrier and timing error estimation algorithm based on non-cooperate reception.By studying AFC dot product algorithm,differential and non-data auxiliary timing error estimation algorithm,an improved timing error estimation algorithm has been found.5.The ultra-wideband frequency-hopping receiver based on VPX bus is designed and implemented.It has 7U VPX cases,6U plug-in modules,and high speed optical backplane.The performance and practicability of the receiver has been verified through tests.