Low Interception Performance Analysis And Design Of Phase Coded Waveform

Radar countermeasure is to make enemy military command system lose combat ability through effectively reconnoitering and interfering enemy radar, and then destroy the enemy and safeguard oneself. Under this background, Low Probability of Intercept (LPI) radar is introduced, and has become one of widely used techniques in radar countermeasure, so research on LPI radar is helpful to improve the radar survival capability in complicated electronic countermeasure environment.From the current development situation of LPI radar and phase coded waveform design, this thesis firstly introduces the basic concept and realization methods of LPI radar; then phase coded waveform, with the property of low probability of intercept, are studied as well as its characteristics; finally, as to the problem of high range sidelobe level of traditional phase coded waveform, methods of designing phase coded waveform with low range sidelobe level are studied. The main contents areThe first chapter describes phase coded waveform and its characteristics in brief, and introduces the research background and research meaning of LPI radar as well as some recent techniques for LPI radar.The second chapter introduces the LPI radar. This chapter mainly consists of three parts. Firstly, the basic principal of LPI radar and the realization methods are introduced, such as the influence of radar antenna, radar transmitter, power management and signal carrier frequency on the LPI radar design; secondly, waveform design methods of LPI radar are introduced, and the anti-interception performance is analyzed; finally, based on the theory of cyclic autocorrelation, blind parameter estimation which is one of the methods of signal detection is studied, and the effectiveness of these methods is verified by simulation results.The third chapter mainly introduces phase coded waveform design. This chapter mainly consists of four parts. Firstly, the idea of mismatch filter is introduced; secondly, phase coded waveform is designed by using least-pth minimax algorithm with the L-BFGS algorithm as its subalgorithm, and the mismatch filter is designed according to this phase coded waveform; thirdly, a method of jointly designing phase coded waveform and mismatch filter is studied; fourthly, based on the real application of radar network system, methods of designing orthogonal phase coded waveforms are investigated.In the fourth chapter, methods of designing phase coded waveform with expanded mainlobe are discussed. This chapter mainly consists of four parts. Firstly, design criterion and optimization algorithm of phase coded waveform with expanded mainlobe width are given; secondly the mismatch filter is designed based on the predesigned phase coded waveform with expanded mainlobe width; thirdly, the method of jointly designing phase coded waveform and mismatch filter is presented; fourthly, joint design criterion of phase coded waveforms with expanded mainlobe width and the mismatched filters is presented; finally joint design criterion of orthogonal phase coded waveforms with expanded mainlobe width and the mismatched filters is presented, and simulation results verify the effectiveness of this method.In the fifth chapter, the content of this thesis is summarized systematically, and the direction of future work is pointed out.