Radar Waveform Design Based On Complementary Sequence

Radar waveform design is one of the key technologies of radar systems,and reasonable waveform selection can effectively improve the target detection capability of radar.Complementary sequences have been widely used in the radar waveform design due to their ideal correlation properties.However,in radar systems,the ideal correlation of complementary sequences will be destroyed in the case of Doppler frequency shift,resulting in the degradation of radar detection performance.On the other hand,the existence of very restricted constituent sequence length of the conventional complementary sequence greatly limits its application in radar waveform design.To address the above problems,this paper focuses on the expansion of complementary sequence parameters and the design of complementary waveforms with Doppler frequency shift tolerance.Firstly,the general construction method of zero correlation zone(ZCZ)complementary sequence set is proposed to fix the problem of limited lengths of traditional complementary sequences,and the phase coding waveform library of multiple input multiple output(MIMO)radar system is constructed based on ZCZ complementary sequences.To address the Doppler sensitivity problem of complementary sequences applied to radar systems,a generalized PTM sequence is applied to adjust the emission order of waveforms to achieve the suppression of distance partials near zero Doppler.It is experimentally verified that the constructed ZCZ complementary waveform set has good Doppler tolerance and better partials suppression performance.Secondly,based on the idea of mismatch reception,a general construction method for obtaining ZCZ complementary sequence pairs sets based on permutation sets and orthogonal matrix pairs is proposed.Since the orthogonal matrix pairs do not have the restriction that the order must be a power of 2,the ZCZ complementary sequence pairs set is constructed in a more flexible way.Furthermore,ZCZ complementary waveform pair set with Doppler tolerance is proposed to fix the Doppler sensitive problem of regular complementary sequences.Simulation results show that the ZCZ complementary pairs waveform set has better Doppler tolerance and lower distance sidelobes.Finally,in order to extend the existence length of complementary sequence pairs,an optimization algorithm is used to generate ε-complementary sequence pairs of arbitrary even lengths.Using the ε-complementary sequence pairs as radar waveform library and the joint waveform processing method with singular value decomposition and standard transmitting and standard receiving to analyze the echo signal of radar.The simulation results show that the constructed waveforms have better Doppler resolution while obtaining a larger sidelobes suppression region,and the joint waveform processing method can well distinguish strong and weak targets in multi-target scenarios.