数字调频信号解调的新方法

An Efficient Method of Demodulating FSK Signals

提出了一种估计强背景噪声中的已知频率信号的新方法 ,然后将该方法应用于数字调频信号的解调。这种新的解调方法只需要知道载波信号的频率而不需要其相位信息就可以完成数字调频信号的解调。计算机仿真表明该方法具有比非相干解调更强的抗噪声能力 ,并且具有相当强的抗相位起伏的能力。因此 ,该解调方法具有良好的工程应用前景。

We extend our method in Ref. to demodulating FSK (frequency shift keying) signals. There are two traditional methods for demodulating FSK signals: incoherent and coherent. Our method retains the advantages of these two traditional methods. In section 1 and appendix, we discuss in detail the principles underlying our proposed method; in particular, by dividing the time sequence of received signals into three sub-sequences and then estimating the spectrum of received signals, our proposed method can complete the demodulation of FSK signals with only information about carrier frequency but without needing any information about carrier phase. Fig. 2 is the flowchart of our proposed method. Simulation results, given in Tables 1 and 2, show preliminarily that our proposed method can be as good as the traditional coherent method in performance but its susceptibility to fluctuation of carrier phase is much less than that of the traditional coherent method.