公开(公告)号：EP2124409A1

公开(公告)日：2009-11-25

申请号：EP08305195.3

申请日：2008-05-23

申请人： Thomson Licensing, Inc.

发明人： Liu, Dun ,  Liu, Gang ,  Du, Yongjiu

IPC分类号： H04L27/26

CPC分类号： H04L27/2665 ,  H04L1/0048 ,  H04L27/2663 ,  H04L27/2675 ,  H04L27/2678 ,  H04L27/2688 ,  H04L27/2695

摘要： A method and apparatus for symbol timing in OFDM systems is described. It includes receiving an OFDM signal transmitted by a plurality of paths; correlating the received signal to do coarse symbol timing; and determining whether the coarse symbol timing needs to be adjusted based on a feedback from FEC decoder.
It finds application by detecting (720) pre-echo paths which are folded due the periodicity property of the IFFT (714).
The echo-identifier (720) fine-tune the timing of the FFT (706) by synchronizing on the far-most resolvable path which is likely to be a pre-echo.

摘要翻译： 描述OFDM系统中符号定时的方法和装置。 它包括接收由多个路径发送的OFDM信号; 将接收到的信号相关以进行粗略符号定时; 以及基于来自FEC解码器的反馈来确定是否需要调整粗略符号定时。 它通过检测（720）由于IFFT（714）的周期性而折叠的预回波路径来发现应用。 回波标识符（720）通过在可能是预回波的最可分辨路径上同步来微调FFT（706）的定时。