MIMO Radar Orthogonal Waveform Design And Experimental System Verification Implementation

Radar plays an important role in the complex and changeable electronic warfare environment.MIMO radar is a new type of radar with multiple input and multiple output.It has a larger virtual aperture than the traditional Phased Array radar,which brings better detection performance,higher Doppler resolution,stronger clutter suppression and anti-jamming performance.The design and optimization of orthogonal waveforms is one of the key technologies of MIMO radar system.The good Auto-and Cross-Correlation characteristics can reduce the probability that weak targets are concealed by the side lobes of nearby strong targets and cannot be detected.In addition,good waveforms can significantly improve the performance of radar system in spectrum suppression,beam pattern matching,target parameter estimation,etc.Therefore,it is very considerable to study the design and implementation of MIMO radar waveform.In this thesis,the orthogonal waveform design and system implementation of MIMO radar are studied mainly for Frequency Division Multiplexing with Linear Frequency Modulation(FDM-LFM)waveform and Phase Coded Waveform based on Cyclic Algorithm-New(CAN).The main work can be summarized as follows:1.Aiming at the problem of waveform verification of multichannel transmitting signals,we have developed the Multichannel Transmitting Subsystem based on the Waveform Diversity Array Radar Test System.We design the DSP module,and verify the consistency of the multichannel of the subsystem through multiple groups of tests,so as to ensure the good performance of the transmission waveform of the hardware test platform.2.In view of the problem of how to analyze the orthogonal waveform of MIMO radar,this thesis summarizes the existing waveform evaluation indexes.Meanwhile,it studies the design and test of FDM-LFM waveforms.Firstly,we present the signal model of MIMO radar and analyze its advantages over traditional Phased Array radar.Secondly,we give the definition and properties of Ambiguity Function,and summarize the existing evaluation indexes of waveform using Ambiguity Function.Thirdly,based on the MIMO radar,we present a Frequency Diversity Array radar model and analyze its transmission pattern characteristics.Finally,we give the baseband signal model of FDM-LFM,analyze itself using the waveform evaluation indexs,and verify the waveform by the Waveform Diversity Array Radar Test System.3.In order to solve the problem of integrating sidelobe and signal spectrum constraints in the design of Orthogonal Phase Coded waveforms,we study an optimal design method of Orthogonal Phase Coded waveforms based on CAN algorithm.This thesis combined the Multi-CAN algorithm with the SCAN algorithm,and proposed the Multi-SCAN algorithm.It not only inherits the efficient computing advantage of CAN algorithm,but also has the multi-sequence design characteristics of Multi-CAN algorithm and the stopband control ability of SCAN algorithm.Under the spectrum constraints,we can optimize the multichannel Orthogonal Phase Coded waveform.In addition,the signal sets simulated by the algorithm are analyzed according to the waveform evaluation index,and the Waveform Diversity Array Radar Test System is used to verify the waveform.In this thesis,based on the theoretical simulation analysis of FDM-LFM waveforms,the characteristics of orthogonal waveforms are obtained by using Ambiguity Function.Then it goes deep into the field of Orthogonal Phase Coding to design the orthogonal waveform which is convenient for hardware system application.Finally,the Waveform Diversity Array Radar Test System is used to verify the waveform.The proposed Multi-SCAN algorithm has a fast waveform design speed and is convenient for real-time updating of MIMO radar waveform.