LFM Signal Analysis Based on Improved Lv Distribution

In this paper, we propose a parameter estimation method named improved Lv distribution (ImLVD) for linear frequency modulated (LFM) signals. In this method, based on the scaling principle, we present a two-scale estimation strategy to acquire low computational cost. The two-scale estimation strategy includes coarse estimation operation and fine estimation operation. To implement the strategy, improved scaled Fourier transform (ISFT) and Chirp-Z transform (CZT) operation are used, where the ISFT can be implemented by fast Fourier transform (FFT) and complex multiplications. By changing the frequency searching range of ISFT, the ISFT is used in different frequency ranges. To improve the anti-noise, we present an improved parameter selection criterion which can reduce the noise correlation effectively. In this paper, the implementation, anti-noise performance, and computational cost are analyzed. Through simulations and analyses, we demonstrate that the ImLVD outperforms the compared algorithms.