基于全极点滑动窗离散短时傅里叶变换的解调

All-pole Moving-windows DSTFT-based PCM/FM Demodulation Method

针对汉宁窗及海明窗等算法计算过于复杂,提出基于全极点滑动窗及离散短时傅里叶变换(DSTFT)的递归算法,用以解调PCM/FM信号。该算法不需要使用传统解调算法中的载波恢复环路,而通过在频域内加入全极点滑动窗,采用离散短时傅里叶变换的方法检测出信号的瞬时谱峰值来实现解调。理论分析和仿真结果表明,该算法误码率低、计算量小。

A novel pulse code modulation/frequency modulation（PCM/FM） demodulation method u- sing an efficient recursive algorithm to compute discrete short-time Fourier transform （DSTFF） of the signal was proposed in this paper. In this approach, instead of excluding the old samples, their importance was dimin- ished by using all-pole moving-windows. The DSTFT-based PCM/FM demodulation method was simple because signal in a time-frequency plane was expanded and demodulated only by searching the instantaneous spectral peaks without complicated carrier-recovery circuit. The computation amount was reduced and the bit error rate （BER） was degraded. Its effectiveness was illustrated by the simulation and test results.