Optimum waveform design and clutter rejection processing for MIMO radar

Multiple-Input Multiple-Output (MIMO) radar has the capability to simultaneously transmit and receive multiple orthogonal waveforms to improve radar performances [1, 2]. The unique structure of MIMO radar, as shown in Fig.1, allows transmitting waveform and signal processing to be optimized to achieve a better radar performance in various areas. Multiple matched filters are used at the receiver for each antenna element to exclusively receive the waveforms transmitted by each element. It has been demonstrated that virtual transmitting and receiving beams can be formed to achieve an optimum signal-to-noise ratio (SNR) in target detection, through digital signal processing at the receiver using arbitrary transmitting waveforms. The actual transmitting antenna beam can be optimized to minimize the radiation power in any direction (or all directions) to achieve a low probability of intercept (LPI) property, without degrading target detection performance. In previous work involving MIMO radar virtual beamforming systems, only SNR and white noise were considered for target detection performance evaluation. However, for some applications such as ground moving target detection, using airborne assets, ground clutter interference is a much more serious threat for reliable target detection. In this work, the MIMO system is further investigated for clutter rejection as well as waveform design for optimizing the actual radar radiation pattern.