MIMO-OFDM系统中一种改进的符号同步算法

Efficient Symbol Timing Estimation Method for MIMO-OFDM Systems

为了提高基于传统训练序列的符号定时同步的精度,提出了一种改进的用于MIMO-OFDM符号同步的正交前导结构。该方法将传统正交前导结构中最后一个短训练序列的前半个周期进行了相位反转,使得基于改进的前导结构的接收信号与自身周期延时信号的互相关结果中产生一个明显的下陷,因此这可以在多径环境下更准确的获得短训练序列与长训练序列的分界点,从而有效的提高多径环境下MIMO-OFDM系统符号同步的精度。仿真结果表明,在AWGN信道及Rayleigh衰落信道下,这种改进的前导结构在符号同步中有很好的性能。

In order to improve the accuracy of the symbol timing conventional method, a modified preamble structure for MIMO-OFDM The proposed method creates a sharp fall in the delayed correlation of synchronization which obtained by using the symbol timing synchronization is proposed. the samples at the last short preamble period by phase reversing the first half of the last short preamble samples and hence helps more reliable estimation of the end of the short preamble or the start of the long preamble boundary especially under high time dispersive channel. The simulation result shows that with channel AWGN and Rayleigh, the improved preamble structure has good performance in symbol timing synchronization.