Joint Transmit Waveform and Receive Filter Design for the DFRC System With Imperfect CSI

Considering the imperfect communication channel state information (CSI), we investigated a robust joint design of transmit waveform and receive filter for the dual-functional radar-communication (DFRC) system using a multi-input-multi-output (MIMO) platform. In this study, we take the output signal-to-interference-plus-noise ratio (SINR) of the radar as the cost function, while formulating communication constructive interference (CI) constraints under imperfect estimation of communication CSI. We also imposed a constant modulus constraint to preserve the unimodular property of the transmitted waveform. To solve the complicated non-convex problem, we developed two efficient algorithms in both Euclidean and Riemannian spaces. The first algorithm used alternative direction methods of multipliers (ADMM) to break down the optimization problem into two solvable sub-problems, which were then solved using the majorization-minimization (MM) method and geometrical structure. The second algorithm converted the communication CI constraints into a distance penalty term, transformed the original problem into Riemannian space, and solved it efficiently using the Riemannian complex circle manifold conjugate gradient method. Finally, extensive simulation results demonstrate the effectiveness and superiority of both proposed algorithms.