基于虚拟无线电的PCM/FM信号解调方法

根据PCM／FM信号的特点，提出了一种基于虚拟无线电平台的信号解调方法。分析了PCM／FM信号的谱特性，给出了利用PCM／FM信号的频谱进行解调的理论基础。根据实际PCM／FM信号的非平稳特性，提出了基于离散短时傅里叶变换（DSTFT），通过比较频点能量进行PCM／FM信号软件化解调的实现方法。详细地论述了此种解调方法的基本原理及实现过程，分析了该方法的解调性能及复杂度。计算机仿真结果表明，该方法对于实际接收的PCM／FM信号具有较好的解调性能，并且实现原理简单，运行效率较高，便于在虚拟无线电平台中实现信号的实时处理。

Method of Demodulation for PCM/FM Signal Based on Virtual Radio

According to the characteristic of PCM/FM signal, a new algorithm of software demodulation was proposed based on virtual radio. Through analyzing the characteristic of spectrum of PCM/FM signal, the basic theory of demodulation by spectrum was got. The method for PCM/FM signal demodulation based on DSTFT was proposed according to the instability of factual PCM/FM signal. The basic theory and the course of realization were discussed, and the performance and complexity of this method were analyzed. The results of computer simulation show that the method has better performance of demodulation, high efficiency for factual PCM/FM signal, and is convenient to realize real-time processing based on virtual radio.