Joint Design of Unimodular Waveform and Mismatched Filter Against Interrupted-Sampling Repeater Jamming via Bi-Objective Optimization

This paper focuses on the joint design of unimodular waveforms and mismatched filters to enhance target detection performance and mitigate interrupted-sampling repeater jamming (ISRJ) through a bi-objective optimization framework. The design aims to achieve favorable correlation properties and control the signal-to-noise ratio loss (SNRL) at the mismatched filter output, while concurrently suppressing both the range processing gain and the ISRJ energy. To evaluate target detection performance, we employ a weighted sum of the integrated sidelobe level (ISL) and an SNRL-related penalty term as the primary metric. Meanwhile, jamming suppression is evaluated by the weighted sum of the jamming integrated level and the jamming peak level. Using these multiple metrics, we formulate the design into a non-convex bi-objective optimization problem with unimodular constraints and energy restrictions. To solve it, we propose an algorithm based on the weighted objectives approach, wherein multiple objectives are reformulated into a single objective function with adaptively determined weighting coefficients. The proposed algorithm dynamically updates the weighting coefficients and obtains a closed-form solution via a multiple-gradient descent-based approach that is followed by projections toward the respective feasibility set at each iteration. Simulations verify the effectiveness of the proposed algorithm.