Frame synchronization of OFDM systems in frequency selective fading channels

This paper investigates the topic of frame synchronization for systems based on the OFDM principle. After introducing the system model we discuss the task of frame-synchronization and analyze the effects of a frame offset. From this we derive an appropriate criterion to measure the performance of synchronization algorithms under multipath conditions. We examine two algorithms for frame synchronization: The first algorithm is based on an evaluation of periodic structures. Since it is completely independent of a frequency offset it may be applied for system acquisition and burst synchronization. If the requirements are very high as in terrestrial TV broadcasting a second algorithm is needed to attain sufficient accuracy. The algorithm presented for this purpose is based on the evaluation of the channel estimate, so no further training data is required.