基于导频信号的MIMO-OFDM同步技术

Research on Synchronization Technology for MIMO-OFDM Systems Based on Preamble Signals

MIMO-OFDM技术将成为第4代移动通信系统的关键技术,因MIMO-OFDM对时间和频率偏移非常敏感,因此MIMO-OFDM同步显得尤为重要。提出了一种新的MIMO-OFDM定时同步和频偏同步技术。以GCL序列为基础设计了一个新的符合MIMO-OFDM同步技术的导频序列,通过对该导频序列进行2次相关得到频率估计,并将所得频率运用到定时同步中,得到更为准确的时间估计。仿真结果表明,在相同的信噪比情况下,该方法可以使得系统的误码率和帧传送误码率相对传统方法得到进一步减小。

MIMO-OFDM will become a key technology of the fourth generation mobile communications system.However,MIMO-OFDM is sensitive to the CFO and timing synchronization,so the MIMO-OFDM synchronization technology is very important.This paper proposes an accurate technique for timing and frequency synchronization of multiple-input multiple-output（MIMO）orthogonal frequency division multiplexing（OFDM）systems.The technique derives a new preamble signal based on GCL sequences,according with the MIMJO-OFDM synchronization.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.The simulation results show 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.