Abstract:

A spectrogram based parameter estimation for pseudorandom binary code and linear frequency modulation (PRBC-LFM) reconnaissance signals is presented. According to the spectrogram characteristic of PRBC-LFM signals, the features related to pseudocode parameters such as subpulse width, pulse cycle and pseudocode cycle, and frequency modulation parameters such as carrierfrequency, modulation slope are extracted．In addition, the affection of choice for the spectrogram window length to parameter estimation precision is analyzed in terms of IF estimation error theory. Moreover, the CramerRao bound  (CRB) of PRBC-LFM parameter estimation is derived to evaluate the performance of the proposed method. Finally, theoretical analysis and simulation results show that the proposed method is comparatively close to CRB when the signal-to-noise ratio is at 0~10 dB and the window length is medium.