Research And Implementation Of Interference Cancellation Technology For Satellite Spread Spectrum Communication

The commercial satellite's military application is the trend of the current military satellite communication technology.The technology can not only improve the communication capacity and speed of military communications,but also provide a secret and reliable communication link for military communications.When the commercial satellite is used for spread spectrum commurication,the interference of strong broadband service signal and the interference of narrowband signal will affect the communication system.A reliable spread spectrum anti-jamming acquisition system is designed to overcome the influence of interference signal and adapt to the large dynamic change of the signal,which is especially important for the spread spectrum communication under the background of commercial satellite.This paper first proposes a frequency selective cancellation algorithm to solve the problem of cross correlation interference generated by the strong broadband business signal in the commercial satellite application,and demonstrates the feasibility of the algorithm in the design by simulation.Secondly,a multi-mode carrier synchronization system is proposed,which realizes synchronous tracking of commercial DVB-S2 signals of four modulation types QPSK,8PSK,16APSK and 32APSK.Then,the window function plus frequency domain narrowband interference cancellation technology is analyzed.The elimination effect of notch algorithm and clipping algorithm is simulated and analyzed,and the feasibility of narrowband interference suppression is demonstrated.At the same time,a parallel acquisition algorithm in frequency domain for large Doppler dynamics is proposed to improve the capture efficiency.Finally,the receiver prototype is measured,and tihe acquisition time of the prototype is recorded by introducing the cross-correlation interference signal and the narrowband interference signal,and the feasibility of the anti-jamming algorithm is demonstrated.The research results show that the frequency selective cancellation method and the frequency domain notch algorithm can effectively suppress the cross correlation interference and narrowband interference,and improve the system's capture ability.