采用DFT实现时FD/SSMA系统的同步分析

本文分析FD/SSMA系统采用DFT实现时的同步原理。FD/SSMA系统的同步包括信息比特定时同步(即DFT的时间窗同步)及系统载波的同步。利用定时同步识别信号、定时同步误差信号、载波频率误差信号及载波相位误差信号可以依次完成FD/SSMA系统接收端定时同步的捕获、锁定及跟踪,载波频率及相位同步。在利用DFT实现的FD/SSMA系统中,由于实现同步的信号处理均可利用数字信号处理技术(DSP),从而使同步的实现更方便。

ANALYSIS OF SYNCHRONIZATION IN THE FD/SSMA SYSTEM WITH DFT IMPLEMENTATION

The principle of synchronization in FD/SSMA (Frequency Diversity/Spread Spectrum Multiple Access) system with DFT (Discrete Fourier Transform) implementation is studied. It is shown that both byte-timing synchronization (i.e. the time-window of DFT transform) and the transmitter' carrier synchronization are needed in this FD/SSMA system. The capturing, locking and tracing of timing-synchronization, the carrier's synchronization about its frequency and phase will be finished in order by the recognizing signals of timing-synchronization and three error signals, of which the timing-error signal, the frequency and phase error signals of the system' carrier are included, where their implementation may be carried out easier due to the DSP (Digital Signal Processing) techniques to be applied.