IRS-Assisted Communication Performance Optimization Method for Shipborne DFRC System

Dual-functional radar-communication (DFRC) has emerged as an effective solution in recent years to address spectrum scarcity in maritime environments, enabling efficient integrated communication and sensing. To mitigate path loss over complex sea surfaces, the intelligent reflecting surface (IRS) is introduced into DFRC systems, enhancing signal quality by providing an additional propagation path. To address the impact of sea wave fluctuations on the communication channel of maritime vessels, an alternating optimization (AO) algorithm based on semidefinite relaxation and fractional programming (SDR-FP) is proposed. First, the non-ideal channel state information (CSI) is modeled using a bounded channel uncertainty model via the S-procedure. Second, under constraints on radar detection performance and transmit power, the problem is formulated to maximize the communication sum-rate. Next, the proposed AO algorithm decomposes the original high-dimensional problem into two low-complexity subproblems. Finally, a minimization algorithm is applied to reformulate the non-convex subproblem into a tractable quadratically constrained quadratic program (QCQP). Simulation results demonstrate that the proposed method significantly enhances the communication sum-rate while achieving faster convergence compared to benchmarks.