Joint Waveform and Frequency Increment Design of FDA-MIMO Radar for Multipath Exploitation

The range-dependent phases induced by Frequency Diverse Array (FDA)-Multiple-Input Multiple-Output (MIMO) radar provide additional degrees of freedom for range related scenarios. This paper investigates the joint transmit waveform and frequency increment design of FDA-MIMO radar to enhance target detection in multipath environments. Specifically, we establish a generalized FDA-MIMO signal model for multipath reception and formulate a Signal-to-Interference-plus-Noise Ratio (SINR) maximization problem over the transmit waveform and frequency increment, while constraining the waveform modulus and increment upper-bound. Leveraging on an alternating optimization framework, we update the waveform via power-method-like implementation and the frequency increment via iterating an analytical expression based on a Majorization-Minimization (MM) scheme. Simulation results indicate that the proposed method achieves a gain up to 14dB over conventional MIMO, demonstrating superior energy focusing effect at target location.