一种基于滑动DFT的信号解调算法

A Signal Demodulation Algorithm Based on Sliding DFT

离散傅立叶变换（DFT）是数字信号分析和处理中常用而有效的手段，在大多数应用中利用的是傅立叶变换后的幅度信息，而忽略了它的相位信息。本文提出了一种基于滑动DFT的算法，利用频域相位信息完成对π／4-DQPSK信号的解调。文中详细阐述了算法的解调原理和过程，给出了两种窗函数下的快速算法，并分析了误码率性能。计算机仿真表明，该算法解调性能良好，运行效率较高，便于软件化实时处理。

Discrete Fourier transform （DFT） is effective and in common use in digital signal analysis and processing. However, in most of the applications, we make use of the magnitude information of the results of DFT, and omit the phase information. The paper brings forward an algorithm based on sliding DFT, which accomplishes the demodulation of π/4-DQPSK signal by using the phase information in frequency domain. The paper elaborates the principle and process of the algorithm, presents the fast algorithms of two different windows, and analyzes the demodulation performance. Computer simulation shows that the algorithm has good performances as well as high efficiency, and is convenient to be realized by software.