Waveform Design For MIMO Radar

MIMO radar requires that each transmitter signal waveform have mutually orthogonal, so it can form low-gain wide beam and help to irradiate multiple air targets at the same time and anti-interception performance radar signals. MIMO radar receiving can form many of plurality of high-gain narrow beam by the digital multi-beam forming technology(DBF), it help to extract parameter information of multiple targets at the same time.Orthogonal waveform design is the key point of MIMO radar systems. Orthogonal waveform design will directly determine that the merits of the performance of MIMO radar are good or bad. Common orthogonal MIMO radar waveform design is divided into two categories: those classified as orthogonal frequency waveform design, one for the orthogonal code classification waveform design. This thesis focuses on the classification code for waveform design issues and research several new optimization method. Combined with engineering background and actual demand, a new multi-phase coding sequence optimization algorithms and optimization measures are proposed. Meanwhile, with the classification of orthogonal frequency waveforms applied, the thesis studies the characteristics of the signal processing under broadband conditions.Therefore, the main contents of this thesis are related:1. Introduced the MIMO radar basic structure and operating principle, discussed the types and form of MIMO radar waveform.2. Studied the quadrature phase encoded signal design method by Walsh matrix, and based on the existing two-phase design, this paper propose a kind of four-phase code design method and presents a long-coded design method for meeting the application of a large array of backgrounds. Compared to the quadrature phase encoded signal design based on genetic algorithm, this method devised orthogonal waveforms that have zero-offset strictly orthogonal between any two waveforms(alignment of the correlation output signal is zero with sliding correlation), thereby it improves the effect of clutter cancellation and the measurement accuracy of the target3. Studied the encoded signal design method based on sequential quadratic programming(SQP). For the actual project object detection is performed after the transceiver joint beam forming, integrated pulse sidelobe will directly affect the output of the target detection. Therefore, this thesis proposed "sum-signal"(the sum of the transmission signal is superimposed) correlation sidelobe into the objective function, it helped to integrated pulse output sidelobe. For the problem of phase’s limitation number, this thesis proposed a kind of phase quantization design method and analyzed of the effects of quantization bits. Finally, with the multi-dimensional diffusion problems of related sidelobe, this thesis studied the space- time- frequency sidelobe of the coded signal dimensional optimization method.4. Studied the MIMO radar signal of orthogonal frequency classification have application features and signal processing method in the broadband. This thesis completed wideband frequency diversity signal processing and analyzed broadband balanced, broadband beam forming and broadband Doppler compensation.