Synchronization for MIMO-OFDM systems based on preamble signals

An accurate technique for timing and frequency synchronization of multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems is proposed in this paper. A new preamble signal which adapts to the MIMO-OFDM synchronization, is derived based on GCL sequences. The carrier frequency offset (CFO) estimation is obtained through taking double correlation operations on the preamble signal, and used in the timing synchronization to gain accurate time estimation. From analysis, it is shown that at the same SNR, the proposed method can reduce the BER and the frame transmission BER of the system compared to the conventional method.