The Research On Key Technology Of High Dynamic Frequency Hopping Communication Receiver

The anti-jamming characteristics and confidentiality of traditional frequency hopping communication are built on the sacrifice of limited communication bandwidth resources and pseudo random coding. For today’s complex electromagnetic environment, its ability of anti-interference has been slightly weak. At the same time, when FH communication is used in satellite communications, the doppler effect caused by the movement is must be considered.In view of insufficient of anti-jamming ability of traditional FH communication technology in today’s complex electromagnetic environment, this thesis uses the blind source separation theory makes the source signals separated from jamming signal. Compared with the traditional FH communication anti-jamming technology, the new method can keep normal communication when communication frequency band covered by the jamming signal. Then, this thesis uses a kind of auto-restart mechanism to reduce the error convergence rate of the algorithm and uses a kind of auto-adaptive rule to solve the problem of inaccurate threshold parameters, the algorithm with resumption can make the error convergence rate reduced to 0.For doppler information estimation of frequency hopping communication system in high dynamic, this thesis modified the LFM signal model according to the characteristics of frequency hopping communication. According to the characteristics of the modified frequency hopping LFM model, we split doppler information estimate into two: long data sequence and short data sequence. For long data sequences, this paper uses FFT-MDCFT algorithm under the premise of ensuring the estimation performance will be small algorithm computation; for short data sequences, this paper presents improved correlation algorithm is used to estimate the Doppler information. Finally, through the simulation experiment test permits the estimation performance of the new algorithm is closer to carat Merlot circles, and SNR threshold value lower than the original algorithm by about 5 dB.