基于CAZAC序列的低复杂度抗频偏同步算法  

Low-complexity and frequency-offset-robust synchronization algorithm based on CAZAC sequence

作　　者：宫丰奎[1] 文妮 李果 高洋[1] GONG Fengkui;WEN Ni;LI Guo;GAO Yang(State Key Laboratory of Integrated Service Networks,Xidian University,Xi’an 710071,China)

机构地区：[1]西安电子科技大学ISN国家重点实验室,陕西西安710071

出　　处：《通信学报》2021年第2期64-71,共8页Journal on Communications

基　　金：国家自然科学基金青年基金资助项目(No.61901325,No.62001354);国家重点研发计划基金资助项目(No.2018YFE0100500);中国博士后科学基金资助项目(No.2018M640958);陕西省自然科学基础研究计划基金资助项目(No.2019JQ-658);陕西省技术创新引导专项基金资助项目(No.2019CGXNG-010,No.2020CGXNG-036)。

摘　　要：提出了一种基于恒包络零自相关(CAZAC)序列的低复杂度抗频偏同步算法,适用于突发正交频分复用(OFDM)系统。由CAZAC序列构造一种新型前导序列,利用该序列的组合特性,推导其简化的定时度量函数,进而利用时延相关和对称相关特性实现精确稳定的定时同步。进一步地,基于所构造的前导序列,提出了一种联合循环前缀的加权频率同步方案,可获得更准确的频偏估计。仿真结果表明,无论是否存在频偏,所提算法在高斯信道、多径衰落信道环境下均具有良好的同步性能,并且其计算复杂度低于大多数现有代表性算法。A low-complexity and frequency-offset-robust synchronization algorithm based on CAZAC sequence was proposed,which was suitable for burst OFDM systems.A new preamble sequence was constructed based on the CAZAC sequence,and its simplified timing metric function was derived by using the combination characteristics of the sequence,and then the delay correlation and symmetric correlation characteristics were used to achieve accurate and stable timing synchronization.Furthermore,based on the new constructed preamble sequence,a weighted frequency synchronization scheme combining cyclic prefix was proposed to obtain more accurate frequency offset estimation.Simulation results show that the proposed algorithm has good synchronization performance in both Gaussian channels and multipath fading channels regardless of frequency offset,and its computational complexity is lower than the most existing representative algorithms.

关 键 词：正交频分复用 恒包络零自相关序列 前导序列 同步 抗频偏 

分 类 号：TN929.5[电子电信—通信与信息系统]