Design Of Phase Coded Waveform And Signal Processing Method

Pulse compression signal is a kind of radar signal with large time-bandwidth product.It can effectively solve the contradiction between radar detection range and range resolution.As a kind of commonly used pulse compression signal,phase coded signal has good performance of compress,anti-interception and anti-jamming,and has been widely used in modern radar.For the phase coded pulse compression radar system,the quality of the original phase code largely determines the performance of the radar.And because the sidelobe of the aperiodic autocorrelation function of the phase coded signal is too high,it limits its application in practice.This paper focuses on the waveform design and the side lobe suppression of phase coded signal.The main contents are as follows:(1)In order to solve the problems of low search efficiency or poor waveform performance in the existing phase coded waveform design methods,this paper proposes an M sequence waveform optimization method based on BPSO.This algorithm designs the low sidelobe M sequences waveform by using BPSO when the echo signal has occlusion and doppler frequency.Simulation results show that the algorithm can converge to a high-quality solution when the M sequence code length is short,and to a relatively better solution when the M sequence code length is long.This algorithm effectively improves the search efficiency and the waveform performance of M sequence waveform design algorithm.(2)Aiming at the problem that the existing combinatorial optimization algorithm is easy to fall into local optimization,this paper proposes AGABPSO.It puts BPSO with adaptive inertia weight as early genetic choice into AGA based on elitism,and judges effectiveness before crossover operator.The algorithm improves the search efficiency while maintaining the population diversity.Simulation results show that the algorithm has strong global search ability and local search ability.(3)Aiming at the problem that the waveform performance of the existing phase coded waveform design methods is not good when the code length is long,this paper proposes an M sequence waveform optimization method based on AGABPSO.The algorithm uses AGABPSO to search the optimal initial register of M sequence and obtain the M sequence echo signal with lowest sidelobe in the presence of occlusion and doppler frequency.The simulation results show that the algorithm can converge to a high-quality solution when the length of M sequence code is longer.This algorithm effectively improves the waveform performance of M sequence waveform design algorithm when the length of M sequence code is longer.(4)In view of the existing phase coded sidelobe suppression algorithm exists large amount of calculation or poor sidelobe suppression performance problems,this paper proposes the adaptive mismatch filtering algorithm.In this algorithm,the idea of optimizing the minimum ISL filtering algorithm is applied to the mismatch filtering algorithm based on convex optimization.The filter designed by this algorithm has the characteristics of less calculation and good sidelobe suppression performance.The simulation results show that the adaptive mismatch filtering algorithm has some advantages over the APC algorithm and the mismatch filtering algorithm in different SNR.