New method for detection and parameter estimation of Stlfm signal

In order to reduce the computation complexity of parameter estimation for STLFM signals, a new algorithm based on Ambiguity Function slice and Fractional Fourier Transform is presented. Firstly, the frequency rate is estimated through one AF slice at fixed time-delay of observation signals, and then getting the best order of FrFT. Finally, the other parameters, including frequency modulation bandwidth, frequency modulation cycle and center frequency, is estimated by twice FrFT. The whole processing just need three times FFT computation complexity and can estimate all the STLFM signal parameters. Simulation results show that the algorithm can estimate the parameters of chirp signal quickly and effectively.