| Orthogonal Frequency Division Multiplexing (OFDM) which is based on multi-carrier modulation can be effective against multi-path interference and have high spectrum efficiency. Multi-Input Multi-Output (MIMO) is a key technology for wireless communication which can significantly increase system capacity and data rates. As the combination of the two technology, MIMO-OFDM system has a high channel capacity and spectral efficiency,and now is becoming one of the core technology of the new generation mobile communication. But on one side, MIMO-OFDM system is sensitive to synchronization error, so the precise synchronization is very important for MIMO-OFDM system.This paper is based on MIMO-OFDM system, and will do a detailed analysis of how the synchronization errors will affect the performance of MIMO-OFDM system as well as do a synchronization research. Based on this analysis, then the synchronization algorithms of SISO-OFDM are discussed in detail. For the deficiencies in the synchronization algorithm on the basis of the analysis of the classic synchronization algorithms, a new algorithms based on sequence-Chu sequence is given. Also, the Chu sequence is used in MIMO-OFDM systems synchronization. The simulation shows that the synchronization algorithm based on Chu sequence having a higher timing synchronization detection probability and low the amount of calculation.Synchronized analysis of the MIMO-OFDM systems of this paper focuses on the burst packet mode, full-time domain synchronization scheme and special preamble structure are used in this paper because of it’s quickly estimation. The improved time synchronization algorithms are given based on the traditional synchronization algorithm, and the simulation results show that the improved algorithm has a higher probability of detection in AWGN and Rayleigh channel. Also, the improved frequency synchronization algorithms using the special structure of the preamble sequence have a smaller offset estimation mean-square error, and the frequency offset estimation accuracy can be improved using diversity reception. |
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