MIMO Radars with Orthogonal Waveforms: A Novel Approach for Enhanced Performance under Swerling Targets

MIMO radar technology has recently attracted attention of large number of research scientists and engineers. Over the last decade, phased array radars have been quite popular because of their beam forming capabilities. In this paper, we propose a novel scheme for an improved performance of radar systems by transmitting orthogonal waveforms from different antennas. We first investigate MIMO radar systems, with orthogonal transmitted waveforms, with regards to their utility for low SNR fluctuating targets. The results show that the conventional mono-static radars are incapable of dealing with low observable fluctuating targets. The highly sophisticated vehicular targets pose great challenge to the ground based radar systems. Thereafter, we propose an algorithm that exploits the time diversity in addition to inherent spatial diversity order of MIMO systems, thereby exploiting the target scintillations and improving the detection performance. The proposed scheme transmits waveforms separated in time such that they experience un-correlated channels. The proposed scheme outperforms mono-static radar and gives a gain of 12 dB with a 2 X 2 MIMO radar system.