Fast Algorithm for Parameter Estimation of LFM Signals under Low SNR

LFM is a typical non-stationary signal and had long been widely used in modern radar and communication system. A new algorithm based on STFT transformation is presented in order to attain fast and accurate estimation of LFM modulation parameters under low SNR. Long window length was employed in STFT to enhance LFM signal, and then shift frequency and accumulate energy based on STFT result to measure FM rate coarsely. Finally, appropriate short window length and search step were employed to search FM rate finely in order to estimate parameter accurately. The proposed method not only reduce the computation but also improve precision of estimating and it is easy to implement.