A Two-step Parameter Estimation Algorithm for Microwave Photonic Spectrum Awareness

Parameter estimation of wideband linear frequency modulation (LFM or chirp) signals is of significant importance in a wide range of areas such as radar, sonar and communications. However, estimation methods based on digital signal processing are limited by the calculation load. Thanks to the intrinsic advantages of large bandwidth, low transmission loss and immunity to electromagnetic interference of modern photonics, microwave photonic techniques are attractive for processing wideband signals. In this paper, a parameter estimation algorithm for the output signal of the photonics-based system is proposed. The algorithm consists of two steps. In the first stage, modified chirp Fourier transform is applied to estimate the parameters roughly. In the second stage, linear fitting and Rife algorithm are performed on the basis of the first step to obtain more accurate results. The simulation results demonstrate the efficacy of the proposed algorithm.