保护带叠加最佳训练序列时间同步方法

Timing Synchronization Scheme Using Superimposed Perfect Training in Guard Band

已成为众多高速无线传输标准的OFDM系统常采用导频插入(PTAM)获得时间同步,然而,浪费了带宽效率.为了改善带宽效率,本文提出在保护带时域叠加弱能量最佳训练序列实现时间同步方法,最佳训练序列的能量分配比例由影响系统BER性能最小而确定.仿真表明:对于低信噪比,在保护带内叠加弱能量序列同步性能与PTAM同步性能相当,且对系统性能影响可以忽略,该法提高了带宽效率.

Orthognal Frequency Divison Multiplexing （OFDM） has been adopted by many high speed transmission standards.Pilot tone assisted modulation （PTAM） is well known technique to achieve timing synchronization information in OFDM but is not bandwidth efficient. To achieve high bandwidth efficiency, we proposed to carry out sperimposed a transparent genralized chirp-like （GCL） training with lower power in the guard band onto the time domain to improve the timing synchronization quality. The power ratio of the GeL sequence is determined by minimizing the system bit error rate （BER） using simulation experiments. Simulation results demonstrate that under medium to low SNR conditions,combing superimposed training with synchronization yields BER performance that is comparable with PTAM;the benefit of the former is that bandwidth efficiency is preserved.