Synchronization Algorithm and VLSI Implementation for OFDM Systems

Aiming at OFDM(orthogonal frequency division multiplex) wireless communication systems,a synchronization algorithm based on 802.11a preamble structure is proposed.The algorithm,based on calculation of the input baseband data energy,first determines the busy state of the channel,then by using the autocorrelation analysis,detects the start point of a frame,and finally by computing the cross-correlation between the input data and the reference training sequence locates the start point of the OFDM symbols and realizes the synchronization.For hardware implementation of the proposed algorithm,the shift-and-add operations and the pipeline technology are adopted,thus to enhance the performance and efficiency of the system.Experiment indicates that the proposed algorithm could provid efficient frame detection and OFDM symbol detection with low complexity of hardware architecture,and thus is proper for VLSI(Very Large Scale Integration) implementation.