摘要
本文基于中国数字广播电视标准候选方案之一的同步多载波扩频(SMCC+)系统,提出了一种低信噪比下高速(250km/h)移动环境的快速同步算法。该算法利用巴克码组码片重复而成的短PN序列产生同步信号,解决了常规同步算法中同步信号多个峰值易误判、门槛值难以选择、频偏估计范围不够大以及低信噪比下同步难等缺点。仿真证明,在-20dB信噪比以上的高速移动AWGN信道和瑞利多径衰落信道环境,与常规算法相比,该法时间同步性能更优,频偏估计范围更大。
This paper proposed a fast, simple and robust synchronization scheme in high-speed (250km/h) mobile environments with lower SNR, based on short pseudo noise sequences (PN-sequence) helped by the Barker codes group, in the context of the Synchronized Multi-Carrier CDMA plus (SMCC+) systems, which is one of the candidate schemes of the Digital Broadcasting Television Standard of China. The scheme regarded the maximal value point as the timing synchronization point to overcome main problems such as many peak values of the synchronization signal, the threshold value hard to choose, the smaller range of frequency offset estimation and difficult to achieve synchronization with lower SNR, etc. Computer simulation results showed that the proposed technique had at least two advantages in high-speed mobile environments under SNR -20dB when compared with the conventional methods. First, the proposed scheme could achieve coarse frequency offset estimation in 1/2 bandwidth, which is much wider than that of the conventional schemes. Second, the proposed scheme could get ideal properties of timing synchronization and timing detection performances, which are much better than that of the conventional schemes. Obviously, the proposed scheme is much better than the conventional schemes.
出处
《信号处理》
CSCD
北大核心
2005年第3期236-239,共4页
Journal of Signal Processing
