关键词: 正交频分复用, 帧同步/DFT窗定时, 多径衰落信道

Abstract: This paper proposes a novel training symbolbased orthogonal fraquency division multiplexing (OFDM) timing synchronization algorithm. This algorithm analyzes the problem of discrete fourier transform (DFT) window timing with error away from cyclic prefix in multipath fading channel where the first path is not the strongest one. In this case the intersymbol interference (ISI) is resulted by the multipaths arriving at the receiver ahead of the strongest path. This new timing algorithm can easily separate different paths and find the strongest one. Considering the fact that the duration of the first path in deep fading will not last for a long time, Alpha filter is applied in timing metric to achieve averaging effect. Moreover search window and threshold are introduced to easily find out the first path at any situation with low complexity and high timing correct probability. This novel timing algorithm is very suitable for wireless multipath environments.

Key words: orthogonal frequency division multiplexing, frame synchronization/DFT window timing, multipath fading channel