短波宽带OFDM系统的一种同步方法  

Synchronization for shortwave broadband OFDM system

作　　者：杨蕾 张友爱[1] 张蕴玉[2] 

机构地区：[1]哈尔滨工程大学信息与通信工程学院 [2]华中科技大学电子与信息工程系,湖北武汉430074

出　　处：《华中科技大学学报（自然科学版）》2007年第1期8-10,共3页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：船舶工业国防科技预研基金资助项目

摘　　要：提出了一种适用于短波宽带OFDM系统的联合同步方法.该方法根据Schmidl和Minn的符号定时原理,传输并处理文中构造的PN序列,并且利用该PN序列的相关性来进行同步判决.此PN序列经反傅里叶变换运算以后产生了OFDM符号,可利用该OFDM符号的特点,通过逐点滑动的自相关运算来判得时间同步的最大值,而后通过OFDM符号每部分之间的相位关系来完成整数频偏与小数频偏的估计.这一过程可同时完成定时偏移估计和频率偏移估计.计算机仿真了三种信道模型,结果表明在三种不同信道下,这种方法都可在较低信噪比条件下很好地完成时间同步和载波频率同步.An associated synchronization is proposed which is suitable for shortwave broadband OFDM （Orthogonal Frequency Division Multiplexing）system, based on Schmidl and Minn＇s symbol timing principle. The constructed PN sequence was transmitted and disposed, and the synchronization was adjudicated by using the correlation of the PN sequence. OFDM symbol was obtained through the PN f sequence operated by IFFT. We used the traits of the OFDM symbol judged the timing synchronization maximum through auto correlation operation slided point by point, and we got the estimation of the integral carrier frequency offset and the decimal carrier frequency offset through the phase relationship of the OFDM symbol＇s each part. The process can achieve the estimation of timing offset and carrier frequency offset at the same time. The computer simulated the method at three kind of channel models. The simulation result indicated the method can complete the system＇s synchronization very well still under the low SNR （Signal Noise Ratio） on those channel models mentioned above.

关 键 词：低信噪比 正交频分复用 联合同步 短波宽带 

分 类 号：TN914[电子电信—通信与信息系统]