Joint Transmit and Receive Beamforming for Multipath Exploitation

Multipath phenomena challenge the target detection process. From another perspective, extra return by multipath propagation provides more target information. Proper use of multipath phenomena can improve radar performance. Concerning an active array radar, the joint transmit and receive beamforming design issue for multipath exploitation is investigated in this paper. We aim to enhance target strength when signal attenuation occurs due to obstacles in the direction of line-of-sight (LoS). The joint design is formulated as a signal-to-interference-plus-noise ratio (SINR) maximization problem that can not be directly tackled. An efficient algorithm based on an alternating scheme is developed to deal with it, where closed-form solutions are given. Simulation results demonstrate that a significant SINR gain can be achieved through multipath exploitation.