基于CAZAC序列的OFDM时频同步方案及FPGA实现  

Timing and frequency synchronization scheme based on CAZAC sequence and its FPGA implementation

作　　者：常凝 闫瑞军[1] 胡涵飞[1] 

机构地区：[1]中国电子科技集团公司第七研究所军工第一事业部,广东广州510310

出　　处：《电子技术应用》2016年第10期108-111,115,共5页Application of Electronic Technique

摘　　要：提出了一种基于CAZAC序列的OFDM时频同步方案,给出了方案各部分的FPGA实现框图和硬件电路实测效果。首先利用时域同步参考符号进行分段相关得出定时估计,然后结合最大似然法进行粗小偏估计,再将同步参考符号和FFT解调变换至频域,利用两个符号中所填充的CAZAC序列的差异性完成整偏估计,最后使用这两个同步参考符号进行细小偏估计。理论分析与仿真结果表明,与传统方案相比,本方案定时估计性能较好,频偏估计精度高,同时具有很好的工程实用性。This paper proposed an OFDM time and frequency synchronization scheme based on CAZAC sequence, and it gave the FPGA implementations of various parts of the algorithm and hardware circuit measured result. First, synchronized symbols are used for timing synchronization with subsection correlation. Then, combining with ML algorithm, coarse frequency estimation is completed.What ′ s more, integer frequency estimation using the difference between two CAZAC sequences which are transferred to frequency domain is accomplished. At last, fine frequency is estimated by the two CAZAC sequences mentioned before. Simulation results show that the scheme gives very accurate estimates of symbol timing synchronization and fine estimation of frequency with good en-gineering practicability.

关 键 词：正交频分复用 CAZAC序列 定时估计 频偏估计 工程实用性 

分 类 号：TN929.5[电子电信—通信与信息系统]