交织正交频分多址上行频偏和定时同步联合盲估计算法

提出了一种基于功率谱叠加的交织正交频分多址系统上行链路载波频偏和定时同步联合估计算法.该算法利用同一用户在各个子载波上具有相同载波频偏的特点,采用一个未受之前符号污染的循环前缀样值,通过抽取自相关矩阵,将属于同一用户的子载波在功率谱上进行叠加,得到更尖锐的谱峰,从而实现对载波频偏的精确估计.对不同时刻估计到的谱峰量级进行比较,可同时实现定时同步.仿真结果表明,算法在估计精度上明显优于循环平稳算法,当一帧中的符号数较大时,算法的估计精度略优于子空间法,且计算复杂度更低.

Joint Blind Estimation for Uplink Interleaved Orthogonal Frequency Division Multiple Access Frequency Offset and Timing Synchronization

A joint blind estimation method based on spectrum overlap for uplink interleaved orthogonal frequency division multiple access carrier frequency offset and timing synchronization is proposed.Using the cyclic prefix samples that are not affected by the fore-symbol and the feature that each user owes the same carrier frequency offset in each sub-carrier,the sharper spectrum peaks are obtained by summing up the sub-carriers' spectrum of the same user and extracting the auto-correction matrix,and then the accurate estimation of carrier frequency offset is realized.Through the comparison of the order of estimated spectrum magnitude at different time,the timing synchronization can be realized simultaneously.Simulation results validate that the proposed algorithm has higher precision than cyclo-stationary method.When the number of symbols in a frame is bigger,it has lower complexity and the estimation precision is slightly better than that of subspace method.