Dual-Functional Radar-Communication Waveform Design: A Symbol-Level Precoding Approach

Dual-functional radar-communication (DFRC) systems can simultaneously perform both radar and communication functionalities using the same hardware platform spectrum resource. In this paper, we consider multi-input multi-output (MIMO) DFRC focus on transmit beamforming designs to provide sensing multi-user communications. Unlike conventional block-level precoding techniques, propose use recently emerged symbol-level approach in systems, which provides additional degrees of freedom (DoFs) that guarantee preferable instantaneous beampatterns for achieve better performance. particular, squared error between designed desired is minimized subject quality-of-service (QoS) requirements users constant-modulus power constraint. Two efficient algorithms are developed solve non-convex problem Euclidean Riemannian spaces. The first algorithm employs penalty dual decomposition (PDD), majorization-minimization (MM), block coordinate descent (BCD) methods convert original optimization into two solvable sub-problems, iteratively solves them algorithms. second a much faster solution at price slight performance loss, transforming space, then utilizing augmented Lagrangian method (ALM) obtain an unconstrained subsequently solved via Broyden-Fletcher-Goldfarb-Shanno (RBFGS) algorithm. Extensive simulations verify distinct advantages proposed