基于HHT算法的轨道信号解调研究

Study on track signal modulation based on HHT

目前常用的FFT解调算法,虽然可以较为容易地得到调制频率和载频,却不容易得到精确的上下边频。本文采用HHT算法,克服了FFT算法的缺点,对ZPW2000轨道信号解调。通过把EMD分解和瞬时频率相结合,并采用归一化算法,解调出轨道信号的调制频率、载频和上下边频。通过仿真验证,用HHT算法完全可以得到轨道信号的高精度解调。

At present,modulation frequency and carrier frequency could be easily got by Fast Fourier Transform（FFT） algorithm,but precise upper and lower side frequency couldn’t be easily got.In this paper,HilbertHuang Transform（HHT） algorithm was introduced to the signal demodulation of ZPW2000.By combining Empirical Mode Decomposition（EMD） with instantaneous frequency and using normalization method to demodulate the modulation frequency,upper and lower side frequency as well as carrier frequency of the track signal.The simulation results showed that HHT algorithm could get the precision demodulation of the track signal.