远动通道FSK信号载频检测方法的研究及其应用

STUDY AND APPLICATION OF THE METHOD OF DETECTING THE CARRIER FREQUENCIES OF FSK SIGNALS IN TELECONTROL CHANNELS

为了实现对基于 FSK(频移键控 )调制方式的远动信道的监控 ,必须首先准确检测 FSK信号的载波频率。 FSK信号的频谱成分比较复杂 ,包含基带信号引入的连续谱和载波信号引入的离散谱两部分 ,传统的信号处理方法难以准确测量。针对以上特点 ,提出了一种新的非线性变换——时域拼接变换 ,通过对 FSK信号的分割和重新组合 ,消除了两个载波信号之间的相关性 ,抑制了基带信号对功率谱的影响 ,将离散谱从功率谱中分离 ,并结合现代功率谱估计方法 ,实现了对信号载波频率的高精度测量。计算机仿真与实验证明 ,该方法是一种有效的

In order to monitor telecontrol channels based on FSK modulation, carrier frequencies should be detected. Owing to the complexity of the ingredients of the frequency spectrum of FSK signals, which contain the continuous spectrum introduced by the baseband signal and discrete spectrum introduced by the carrier signal, it is difficult to accurately measure the frequency ingredients of FSK. A new nonlinear transform called time domain joint is presented in this paper. In this method, through segmentation and recombination of the FSK signals, the correlation between two carriers is eliminated and the effect of the baseband signal on the power spectrum is restrained. As a result, the discrete spectrum of FSK signal is separated from the FSK power spectrum. By combining with the prevailing power spectrum estimating method, high precision measurement of the carrier frequency of FSK is realized. It is proved through computer simulation and experiment that this method is effective for measuring carrier frequencies of FSK.