一种改进的分布式MIMO-OFDM系统同步方案

本文研究了分布式MIMO-OFDM(多输入多输出-正交频分复用)系统的同步估计问题,提出了一种新颖的天线间定时偏移和载波频偏估计算法.该算法设计了一种新颖的基于Gold码良好的正交特性的训练序列,训练序列长度为1个OFDM符号.该算法有效地降低天线间干扰, 在低信噪比的时候产生尖锐的定时度量函数波形,能够精确地估计各发射天线的迟延和载波频偏.相比于分布式MIMO-OFDM系统下的同步算法,提出了算法显示了更高的定时估计精度,和更低的计算复杂度,具有很好的实用价值.仿真结果表明,在AWGN信道下,信噪比为-2 dB时,定时捕获的概率超过99%.

Improved timing synchronization for distributed MIMO-OFDM system

A novel timing synchronization methods involved with time offset between antennae and carrier frequency offset estimation algorithm are proposed for the distributed MIMO-OFDM configuration.The proposed method uses one specifically designed training symbol which is composed of two repeated parts with special sign inversions in accordance with a Gold sequence.This type of training symbol achieves considerable symbol timing accuracy,steep timing measuring function waveform could be generated under low Signal-to-Noise Ratios(SNRs)which can accurately estimate the delay of each transmission antennae as well as the carrier frequency.Compared with synchronization algorithm in distributed MIMO-OFDM system,the proposed algorithm shows higher timing estimating precise,and lower computing complexity,which make it much more practicable.The simulation results show that with channel AWGN and-2dB of SNRs,the probability of timing capture can exceed 99%.