Research On Prediction Algorithm Of Frequency Hopping Code Sequence

FH communication is to use the active way to avoid the enemy interference to achieve the purpose of anti-jamming,so the initiative is very strong.For the system with narrow hop frequency,the interference can be suppressed by power wideband.But for some of the unmanned aerial vehicle frequency hopping communication system or jump long communication system,if need to intercept only a fraction of the frequency of the enemy effectively predict subsequent frequency point,and to forecast tracking interference,so it can reduce the intensity of the interference power of the enemy and the promotion of portability of jamming equipment.In this paper,the prediction algorithm of FH code sequence is mainly studied.By receiving the sequence of frequency points in the past time,the modeling is carried out to predict the sequence of frequency points in the future time,and some algorithms are improved.At the same time,the algorithm analysis under the condition of error code or noise is discussed.The main work of this paper is as follows:1.The theory of frequency hopping code sequence generated by different sequence is introduced in detail.The method of frequency hopping prediction and the applied scene conditions are summarized and analyzed.For different FH code sequences,the sequence distribution and high-dimensional phase diagram are simulated and analyzed,and the overall scheme of FH code sequence prediction is designed.2.In view of the problem that the structural parameters of L-G tap model generated by M sequence are reconstructed and restored based on B-M algorithm under the condition that the actual frequency hopping sequence pattern is received,there are many prior information requirements when the structure parameters of L-G tap model generated by M sequence are reconstructed and restored.This paper provides a structure restoration method of M sequence frequency hopping code based on dynamic reconstruction.The method can judge and modify dynamically according to the real-time received skip frequency by adding the decision condition,and finally solve the correct L-G structure parameters.3.In the case of missing,error and increment of the received frequency hopping sequence,the method is provided by analyzing the situation,and the feasibility of the algorithm is verified by simulation successfully.The results of the improved algorithm under different code error conditions are simulated and compared.The prediction algorithm based on the shift register property is introduced and simulated.4.The principle and process of phase space reconstruction were introduced and deduced,and the phase space reconstruction parameters of chaotic sequence were analyzed and solved by C-C algorithm according to parameter Settings and simulation graphics.For the prediction algorithm of chaotic sequence,this paper introduces the application of RBF neural network prediction algorithm and Volterra adaptive filter in the prediction of chaotic sequence.By comparing the prediction performance of the two algorithms in one step and multi-step chaotic sequence without noise and with noise,the performance of multi-step prediction under different training lengths and different signal-to-noise ratios is compared.Finally,according to the comparison results,the performance difference of the two algorithms in predicting chaotic frequency hopping code sequence under different conditions is analyzed.