Symbol-Level Precoding Design for Dual-Functional Radar-Communication Systems

In dual-functional radar-communication (DFRC) systems, the transmit beamforming has attracted extensive attentions since it can simultaneously provide radar sensing functionality and high-rate wireless communications. Unlike the conventional linear precoding technology, in this paper we propose to employ the recently emerged symbol-level precoding technique in DFRC systems, expecting to take advantages of the multiuser interference for improving both radar and communication performance. The difference between the designed and desired beampatterns is minimized subject to the quality-of-service (QoS) requirements of communication users and the constant envelope power constraint. Some derivations are developed based on the penalty dual decomposition (PDD), majorization-minimization (MM), and block coordinate descent (BCD) methods to convert the non-convex problem into two solvable sub-problems, which are iteratively solved using efficient algorithms. Simulations illustrate the effectiveness of the symbol-level precoding in DFRC systems and the proposed algorithm.