一种改进的用于TDS-OFDM系统的频率同步算法  

An Improved Frequency Synchronization Algorithm For TDS-OFDM System

作　　者：魏恒[1] 方琪[1] 

机构地区：[1]中国传媒大学广播电视数字化教育部工程研究中心,北京100024

出　　处：《中国传媒大学学报（自然科学版）》2013年第3期58-62,共5页Journal of Communication University of China：Science and Technology

摘　　要：本文提出了一种改进的用于采用交替伪随机(PN)序列的TDS-OFDM系统的频率同步算法。改进算法理论支持来源于传统算法中延长频偏估计的相关延迟长度能够极大地改善频偏估计精度,并利用TDS-OFDM系统中两个相邻的PN序列之间存在的最小相同符号以达到延长相关延迟长度的目的。相比于传统的频偏估计,改进后的频率同步算法能够将归一化后的频偏估计方差从10-8降至到10-12。同时改进后的同步算法通过对传统算法的推导理论进行简化,实现只需得到接收信号就可完成频偏误差估计,这比起传统算法需要接收信号与本地产生的PN序列相关后才能得到频率误差估计,改进后的算法会显得更有效率。This paper proposed an improved frequency synchronization algorithm for ahernating pseudo- random number （PN） sequence in the TDS-OFDM-Based DTTB system. It utilizes the minimum length of identical PN sequence exist between two adjacent signal frame to extend the equivalent length of the delay for autoeorrelation which has proved by conventional frequency synchronization algorithm can dramatic improve the precise of frequency estimation. The variance of the frequency estimation over a typical DTTB Rayleigh channel can dramatic decreased from 10^-8 ,in the conventional algorithm,to 10^-12 by using the proposed algorithm. And compare to the conventional frequency algorithm which need to generate local PN sequence to achieve frequency estimation,the improved frequency algorithm only need the received signal to do so that makes the improved algorithm much more efficiency.

关 键 词：TDS-OFDM 频率同步 PN序列 载波频率偏移(CFO) 归一化频偏估计方差 

分 类 号：TN915[电子电信—通信与信息系统]