Detector and Waveform Design of Mimo System

It has been shown that time reversal (TR), which is developed in the acoustics domain, can also improve the detection performance of a radar system. However, the TR technique is no longer a good choice when the noise level is high since the retransmitted signal contains significant noise components. We investigate a multiple input-multiple output (MIMO) detection process similar to TR detection, during which a waveform designed based on the estimated channel and a parameter indicating the quality of the estimation given a priori is retransmitted, and the detector determines the presence or absence of a target. We develop three detectors, whose theoretical thresholds are derived in closed form. Two schemes are proposed to design the retransmitted waveform with constraints on signal power. We compare the detection performance of different detectors, showing that the detector performing the best has the highest complexity, while the detector with the poorest performance demands the least amount of a priori information. Numerical results also present that both the designed waveforms achieve significant performance gains compared with the signal utilized in the TR process.