Study On Transmit Waveform Design And Signal Processing For MIMO Radar

Waveform design problem is a crucial technique for MIMO radar implementation. MIMO radar transmits orthogonal waveforms, such as polyphase coding waves and discrete frequency-coding waves. Uncorrelated waveforms result in broad spatial pattern, or omnidirectional spatial pattern which is usually used to achieve all space search, instead of a narrow beampattern. But when the azimuth of the target is known, for the purpose of detection resolution, or in a tracking mode, orthogonal waveform is not a good selection any more. In this case, we exploit the signals that lie between the extremes of perfect coherence and mutual orthogonality. Arbitrary transmit beampattern can be achieved or approximated via choosing the transmit signals flexibly.Firstly, study the signal processing for MIMO radar including multi-signal matched filter and digital beamforming. Meanwhile compare the MIMO radar and the Synthetic Impulse and Aperture Radar (SIAR). Then two methods for waveform design based on transmit beampattern have been introduced here. The central idea of the methods is that the cross-correlation matrix can be chosen to achieve or approximate the desired beampattern. Once the cross-correlation matrix has been determined, we can synthesize the transmit signal. Gradient search algorithm and squared error optimization are studied and analyzed in the thesis. On the condition that the desired beampattern is a medium size pattern, these methods show good performance on the beam synthesis. The research on the orthogonal waveform design is also included. Investigate the design and the performance of the orthogonal polyphase coding waveform. Lastly, combined with certain project, complete the implementation for SIAR signal processing including digital beamforming, impulse synthesis and impulse compression, and also design the data processing flow and the processing timing sequence.