Sidelobe Level Reduction in ACF of NLFM Waveform

TL;DR

This paper introduces an iterative optimization method for NLFM waveform design that significantly reduces sidelobe levels in the autocorrelation function, outperforming traditional stationary phase approaches.

Contribution

It presents a novel iterative constrained optimization technique for NLFM waveform design, achieving lower sidelobe levels and guaranteed convergence.

Findings

Peak sidelobe level reduced by about 5 dB on average.

Method converges with decreasing minimum error in each iteration.

Achieves an optimal peak sidelobe level compared to previous methods.

Abstract

In this paper, an iterative method is proposed for nonlinear frequency modulation (NLFM) waveform design based on a constrained optimization problem using Lagrangian method. To date, NLFM waveform design methods have been performed based on the stationary phase concept which we have already used it in a previous work. The proposed method has been implemented for six windows of Raised-Cosine, Taylor, Chebyshev, Gaussian, Poisson, and Kaiser. The results reveals that the peak sidelobe level of autocorrelation function reduces about an average of 5 dB in our proposed method compared with the stationary phase method, and an optimum peak sidelobe level is achieved. The minimum error of the proposed method decreases in each iteration which is demonstrated using mathematical relations and simulation. The trend decrement of minimum error guarantees convergence of the proposed method.