Coherent multiple-input multiple-output (MIMO) radar has been shown to offer many advantages over conventional phased-array radars. However, it is know that the overall transmit gain of coherent MIMO radar is lower than that of phased-array radar due to the employment of orthogonal waveforms, which leads to lower signal-to-noise ratio (SNR) levels. Although subarray-based MIMO radar (e.g. phased-MIMO radar) provides higher transmit gain compared to coherent MIMO radar, the transmit degrees of freedoms (DOFs) are reduced as a trade-off. In this work, the loss of SNR in coherent MIMO radar is compensated by using longer coherent processing intervals (CPI) in combination with a reduced dimension interference mitigation algorithm. It is demonstrated by simulation results that once the SNR loss is compensated for, coherent MIMO radar outperforms both phased-array radars and subarray-based MIMO radar, in airborne radar ground moving target detection.
