OFDM系统改进的定时同步算法  

OFDM timing synchronization algorithm based on CAZAC sequence

作　　者：张秀艳[1] 高岩 ZHANG Xiu-yan;GAO Yan(Northeast Petroleum University,Institute of Electrical and Information Engineering,Daqing 163318,Heilongjiang Province,China)

机构地区：[1]东北石油大学电气信息工程学院,黑龙江大庆163318

出　　处：《信息技术》2020年第12期77-81,85,共6页Information Technology

摘　　要：针对OFDM系统由于定时度量函数存在副峰干扰造成同步误差的问题,文中提出一种改进的定时同步方法。基于恒包络零自相关(CAZAC)序列作为同步的训练序列,构建新的训练序列结构。基于新的训练序列改进定时度量函数中归一化因子的计算方法,使定时度量函数在正确定时点呈现较高峰值的同时削减副峰干扰。经过仿真验证,在高斯信道、瑞利衰落信道下,文中算法的定时同步正确率及均方误差都优于其他算法,提升了定时精度。在低信噪比时,文中算法仍能呈现良好性能,保证定时抗干扰性,且在时域完成,计算复杂度低,易于实现。Aiming at the problem of synchronization error caused by secondary peak interference in OFDM system,an improved timing synchronization method is proposed.a new training sequence structure is constructed based on the constant envelope zero autocorrelation(CAZAC)sequence as a synchronized training sequence.Based on the new training sequence,the normalized factor in the timing metric function is improved,and the secondary peak interference is reduced while the timing metric function presents a higher peak at the correct timing point.The simulation results show that the timing synchronization accuracy and mean square error of this algorithm are better than other algorithms in Gauss channel and Rayleigh fading channel.At low signal-to-noise ratio(SNR),this algorithm can still show good perfor-mance,ensure timing anti-interference,and complete in time domain,low computational complexity is easy to achieve.

关 键 词：OFDM CAZAC序列 定时同步 瑞利衰落 

分 类 号：TN929.5[电子电信—通信与信息系统]