OFDM系统在多径衰落信道下的时钟同步  

Clock synchronization in OFDM systems over multipath fading channels

作　　者：董斌[1] 王匡[1] 仇佩亮[1] 

机构地区：[1]浙江大学信息与电子工程学系,浙江杭州310027

出　　处：《浙江大学学报（工学版）》2005年第7期935-938,共4页Journal of Zhejiang University：Engineering Science

摘　　要：为消除时钟同步误差对正交频分复用(OFDM)系统的影响,提出了一种可工作在多径衰落信道下的时钟同步方法.该方法分为时钟频偏估计和时钟频偏补偿两个步骤,在估计时钟频偏时,利用了相邻符号的相邻导频之间的相关性;在补偿时钟频偏时,采用了数字内插环路,这使得时钟同步模块可在全数字接收机中实现.该方法的一个好处是,当存在载波频偏时仍可正常工作,这说明时钟同步可在载波同步之前完成.结果表明,该方法具有足够大的时钟频偏捕捉范围,可用于IEEE802.11a系统和DVB-T系统的接收机中.For eliminating clock synchronization error in orthogonal frequency division multiplexing（OFDM） systems, a clock synchronization method worked over multipath fading channels was proposed.The method includes two steps： estimating clock frequency offsets between the receiver and the sender,and compensating clock frequency offsets. When estimating clock frequency offsets, the correlation between adjacent pilots of two consecutive symbols is utilized; when compensating clock frequency offsets, a digital interpolator loop is adopted, which enables the implementation of the clock synchronization module in all digital receivers. The advantage of the method is its independence of carrier frequency offsets, so that clock synchronization can be established prior to carrier synchronization. The method has wide scope of clock frequency capturing, and can be used in the receivers of IEEE 802. lla systems and DVB-T systems.

关 键 词：正交频分复用(OFDM) 时钟同步 码间干扰(ISI) 信道间干扰(ICI) 

分 类 号：TN929.5[电子电信—通信与信息系统]