LFM Signal Parameters Estimation Using Optimization Approach Initialized by Lipschitz Constant Assisted DIRECT Algorithm

In this paper, the widely used numerical optimization method for estimating linear frequency modulated signal parameters is modified. To this purpose, an improved Dividing RECTangles (DIRECT) algorithm, called the Lipschitz constant assisted DIRECT (L-DIRECT) algorithm, is proposed to substitute for the commonly used Grid Search method. The proposed global optimization algorithm can provide initial estimates for local optimization algorithms such as Newton and Simplex. Based on the classical DIRECT algorithm, the L-DIRECT algorithm eliminates hopeless areas, suspends unlikely areas, and concentrates on promising areas in search space, thus determining the range of attraction for local optimization algorithms with lower SNR thresholds or lessened computational burdens. The effect of the modification is validated by simulation results.