基于DFT的位同步算法及其实现  

Algorithm of Bit Synchronization Based on DFT and Its Realization

作　　者：谭雪琴[1] 蒋立平[1] 王建新[1] 刘中[1] 

机构地区：[1]南京理工大学电子工程与光电技术学院,江苏南京210094

出　　处：《南京理工大学学报》2007年第6期758-761,共4页Journal of Nanjing University of Science and Technology

摘　　要：为了更加快速有效地传输信息,研究了1种基于离散傅里叶变换(DFT)的位同步算法,考虑到调制码元波形具有稳定区和过渡区,该算法只对稳定区内的信号采样值按照载波周期做DFT运算提取幅值,通过检测幅值极小值来实现位同步。直接利用调制信号获取位同步信号,不从恢复的基带信号中提取,使得位同步的建立较容易,降低了计算量,简化了通信系统的解调过程。Matlab仿真结果证明:该算法实现位同步的速度快,且在信噪比不低于5 dB时的同步效果都很好,体现了较强的抗噪性,可以满足实际工程的要求。In order to transfer information more quickly and effectively, this paper presents a bit synchronization algorithm based on discrete Fourier transform （DFT）. The modulated signal has stable and transitional section, and only the DFT of the stable section samples is calculated in one carrier period. The DFT amplitude is extracted and the bit synchronization is realized after detecting the local minimum of amplitudes. The presented algorithm gets bit synchronization information from the modulated signal directly, rather than from the restored baseband signal. It fastens the synchroniza- tion process, reduces the calculation complex and simplifies the communication system＇s demodulation process. The Matlab simulation results show that the algorithm can establish bit synchronization quickly and that its performance of synchronization is good enough to satisfy the engineering demand when the signal noise rate is not less than 5 dB.

关 键 词：位同步 离散傅里叶变换 载波 极小值 解调 

分 类 号：TN914.3[电子电信—通信与信息系统]