Research On Adaptive Frequency Hopping Technology In Frequency Hopping Communication

Nowadays,the electromagnetic environment is becoming more and more complex,and the means of electromagnetic interference are becoming more and more diverse.Adding adaptive technology on frequency hopping communication can effectively improve the anti-interference ability of frequency hopping communication system and make the system adapt to more diverse interference situations.The traditional adaptive frequency hopping communication can only simply distinguish whether the frequency points are interfered or not,and the discrimination of the interference degree of each frequency point is not clear.It only has good effect in dealing with high-intensity interference,and is easy to be affected by low-intensity interference.In the past,the interference considered in adaptive frequency hopping communication are only ordinary fixed frequency interference and tracking interference.In the face of non persistent interference and random hopping interference which make channel quality evaluation invalid,adaptive function cannot be realized normally,and communication quality is difficult to guarantee.This thesis focuses on these issues.The specific content is as follows:Firstly,the traditional adaptive frequency hopping communication system is studied.In order to solve the problem that the traditional adaptive frequency hopping algorithm has low utilization rate about the result channel quality evaluation and difficult to avoid low intensity interference,a probability adaptive frequency hopping algorithm based on the SNR of frequency points is proposed.Compared with the traditional adaptive frequency hopping,the BER can be reduced effectively and the anti-interference ability of the adaptive frequency hopping system can be improved.Secondly,the power adaptive control technology is studied.To solve the problem that all frequency points are allowed to participate in the communication and the communication quality can not reach the perfect state,an improved adaptive frequency hopping algorithm based on power adaptive control is proposed.Combining the advantages of traditional adaptive frequency hopping and probabilistic adaptive frequency hopping,it can not only effectively identify low-intensity interference,but also eliminate the influence of high-intensity interference,and greatly improve the quality of communication.Thirdly,a frequency assignment algorithm based on interference statistics is proposed for partial band non persistent interference,which makes up for the memoryless problem of adaptive frequency hopping communication,effectively solves the influence of partial band non persistent interference on communication,and enriches the types of interference that adaptive frequency hopping communication can handle.Fourth,for the random hopping interference,a multi frequency point frequency hopping algorithm is proposed,which effectively reduces the influence of random hopping interference on the communication quality.It improves the communication efficiency in good channel environment and enhances the anti-interference ability in the bad channel environment.The simulation results show that the proposed algorithm can improve the communication quality significantly,and the anti-interference ability of adaptive frequency hopping communication system is improved.