多径衰落信道下MC-CDMA信号扩频序列周期盲估计  

Blind estimation of spread spectrum sequence period for MC-CDMA signals in multipath fading channels

作　　者：张天骐[1] 杨凯 赵亮[1] 宋玉龙[1] ZHANG Tianqi;YANG Kai;ZHAO Liang;SONG Yulong(Chongqing Key Laboratory of Signal and Information Processing , Chongqing University of Posts and Telecommunications, Chongqing 400065 , Chin)

机构地区：[1]重庆邮电大学信号与信息处理重庆市重点实验室,重庆400065

出　　处：《系统工程与电子技术》2017年第12期2803-2809,共7页Systems Engineering and Electronics

基　　金：国家自然科学基金项目(61671095;61371164);重庆市教育委员会科研项目(KJ130524;KJ1600427;KJ1600429);信号与信息处理重庆市市级重点实验室建设项目(CSTC2009CA2003)资助课题

摘　　要：针对多径衰落信道下多载波码分多址(multi-carrier-code division multiple access,MC-CDMA)信号扩频序列周期盲估计问题,提出自相关二阶矩和循环自相关两种算法。通过分析多径衰落信道条件下MC-CDMA信号的自相关二阶矩,估计出MC-CDMA信号的扩频序列周期。通过分析多径衰落信道条件下MC-CDMA信号的循环自相关,估计出MC-CDMA信号的扩频序列周期。最后在不同信道条件下分别对这两种算法进行仿真,并对两种算法的性能进行对比分析。理论和仿真实验表明,在较低信噪比下,循环自相关算法在估计MC-CDMA信号扩频序列周期时具有良好的性能,但自相关二阶矩算法比循环自相关算法计算复杂度低,易于实现。To solve the problem of blind estimation of spread spectrum sequence period for multi-carrier-code division multiple access（MC-CDMA）signals in multipath fading channels,two algorithms,second-order moment of autocorrelation and cyclic autocorrelation,are proposed.By analyzing the second moment of autocorrelation for the MC-CDMA signal under the multipath fading channel condition,the spread sequence period for the MC-CDMA signal is estimated.By analyzing the cyclic autocorrelation of MC-CDMA signals under the multipath fading condition,the period of spread sequence of MC-CDMA signals is estimated.Finally,the two algorithms are simulated respectively under different channel conditions,and the performance of the two algorithms is compared and analyzed.Theoretical and simulation results show that the cyclic autocorrelation algorithm has good performance in estimating the spread spectrum sequence period for MC-CDMA signals at a low signal-tonoise ratio,but the second-order moment of autocorrelation algorithm has lower computational complexity than the cyclic autocorrelation algorithm,and this algorithm is easy to implement.

关 键 词：多载波码分多址信号 多径衰落信道 自相关二阶矩 循环自相关 

分 类 号：TN911[电子电信—通信与信息系统]