Detector and Waveform Design for MIMO Radar System with Noisy Channel Estimation

It has been shown that time-reversal (TR), which was 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 using the estimated channel and a parameter indicating the quality of the estimation is retransmitted, and the detector determines the presence or absence of a target. We develop three detectors, whose theoretical thresholds and probabilities of detection are derived. Three schemes are proposed to design the retransmitted waveform with constraints on signal power. The designed detectors require different amounts of a priori information, whose performance is compared and analyzed. Numerical results show that all the three designed waveforms can improve the system performance significantly compared with the TR approach, but such enhancement is gained at the price of knowing the quality of channel estimation a priori.