| As one of the physical layer technology, OFDM has been concerned widelyfrom experts and scholars in the next generation wireless communication systems,because it has great advantages of resisting frequency selective fading and veryhigh transmission rate and frequency domain efficiency. The efficiency of signaltransmission is one of the most prominent problems in the current orthogonalfrequency division multiplexing. OFDM technology has a strong sensitivity tooffset problems, so signal is easy to be distorted when it is being transmitted inthe channel which will reduces the efficiency of signal transmission. In responseto these inadequacies, this paper has researched on timing synchronizationalgorithm of OFDM system in multipath channel based on the previous reviewand summary of findings on OFDM technology.The first, this paper has analyzed the classic synchronization criteria ofOFDM systems. The second, this paper analyzed the impact of carrier frequencyoffset and DFT window timing synchronization error to the OFDM systemperformance theoretically. The result shows that these inadequacies will reducethe effective signal-to-noise ratio of the received signal. Based on the currentreview and summary of findings on OFDM technology, this paper has researcheda new timing synchronization algorithm of OFDM system in multipath channelwhich used rule sets to optimize the correlation function and derivate function tomake variance get smaller and smaller. The algorithm not only overcomes theimpact of the multipath channel that the strongest diameter is not the first root ofthe diameter, but also suitable for large-scale network of multi-mode terminalcommunication. Even more, this algorithm is able to maintain the coarsesynchronization when the network is switching in multipath fading channel. Inthe end, this paper compare the simulation results with related algorithms, theresults shows that the new algorithm has a higher timing estimation accuracy. |
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