Design Considerations for a Shipboard MIMO Radar for Surface Target Detection

An active phased array radar or a navigation radar is used in many navies around the world for surface target detection. Multiple-input multiple-output (MIMO) radar differs from current technology by using orthogonal waveforms on transmission which allows it to form a virtual array and conduct beamforming on reception. These differences introduce many advantages, but also some critical design considerations. Specifically, Doppler returns from a target have a greater effect on a MIMO radar due to its inherit requirement to integrate longer to maintain the same signal to noise ratio (SNR) as a phased array radar (PAR). In this paper, a Simulink-based MIMO radar model is developed to evaluate the performance of a naval MIMO radar against a PAR and provides a design restriction on the coherent processing interval (CPI) for detecting moving targets while highlighting the importance of selecting an operating frequency. Simulation results demonstrate that Doppler returns have a more profound effect on the probability of detection in a MIMO radar than they do in a PAR. Simulations also show that a MIMO radar shares the same two-way beam pattern as a PAR when using the same antenna structure and that a MIMO radar searches a large area and refreshes the radar picture faster than a PAR, but at a cost of additional computations.