FPGA implementation and experimental performances of a novel timing synchronization method in MIMO-OFDM systems

This paper proposes a novel preamble structure and a timing synchronization method for OFDM systems. The preamble structure has both properties of delayed and symmetric correlations which can afford accurate time and frequency synchronization simultaneously. A new timing metric is also proposed according to the preamble structure, which is the production of the modulus of delayed and symmetric correlation profiles. The proposed algorithm has been implemented with FPGA in MIMO-OFDM testbed. The measured timing performances are well accordance with the simulation results. The timing performance is very accurate when SNR is larger than 5 dB, that the probability of timing shift compared to the first path less than 10 samples is above 99.5% in 3GPP case 2 channel. And the timing shifts only distribute on several discrete positions. Furthermore, the timing synchronization can work well in high mobility environment up to 500 km/h.