Design of unimodular sequences with small PSL

Abstract

In this paper, we address the intra-pulse coding for single-input single-output radar systems. As the design metric, we consider the peak sidelobe level (PSL), which is important to be small to avoid masking of the weak targets in the range sidelobes of a strong target. The optimization problem, i.e., minimizing the PSL, is Np-hard in general. The adopted constraint is constant modulus, which is practically important in radar systems, as transmit power amplifiers are typically working in saturation, i.e., transmitting constant amplitude probing signals. The imposed constraint is non-convex that increases the complexity of the problem. By the mathematical manipulation proposed in this paper, we convert the non-convex problem to a convex one and tackle it using semidefinite programming. Simulation and results show the obtained sequences have very small PSL values.