非合作USB测控信号调制指数估计算法

Modulation index for telemetry tracking and command (TT&C) signals can be used as a stable characteristic parameter for non-cooperative satellite emitter identification. Aiming at the non-cooperative unified S band (USB) TT&C signals, a modulation index estimation algorithm based on frequency domain spectrum analysis is proposed. According to the spectrum characteristics of the signal, the modulation index estimation algorithm is constructed, and the estimation error of the algorithm is analyzed theoretically. Monte Carlo simulation shows the variation of estimation error with the signal to noise ratio, and the performance of the algorithm is verified by the measured signal in both frequency and time domains. The results show that the spectrum amplitude error between the measured signal and the recovered signal is small, the time domain baseband signal waveform has high consistency, and the maximum value of normalized cross-correlation function is close to 1, which further shows that the proposed algorithm has high precision and can provide high precision parameter support for non-cooperative satellite emitter identification.