This paper analyzed the generation structure of DDFM signal, got the expression in time domain, then applies the modified Bessel function of first kind, then got the analytical expression of frequency spectrum based convolution in frequency domain.

• 本文分析了DDFM信号的发生结构,求得其时域解析式,进而引入一阶变质Bessel函数,最后通过频谱卷积的方法求得了DDFM的频谱解析式。