MC-DS-CDMA系统载波频偏估计的隐导频算法

Carrier Frequency Offset Estimation Using Hidden Pilots in MC-DS-CDMA Systems

针对多载波直扩码分多址(MC-DS-CDMA)系统上行链路的多用户载波频偏(CFO),提出了一种基于隐导频的载波频偏估计算法。该算法利用信息符号和隐导频信号的不同统计特性,在接收端分段近似分离出仅包含对应用户的隐导频信号成分,经过幅角提取得到各用户的载波频偏估计值。该算法能节约信号发送带宽并且计算复杂度低,适合在载波频偏细估计阶段跟踪频偏。仿真结果表明,该算法在使用较低隐导频功率时的频偏估计误差也能满足正交频分复用(OFDM)系统对频偏误差的要求。

For the multiple carrier frequency offset （CFO） problem in the uplink of MC-DS-CDMA systems, an algorithm of carder frequency offset estimation based on hidden pilots is proposed. By exploiting different statistical properties of the data symbols and the hidden pilots, the algorithm approximately separates the components of hidden pilots containing only the corresponding users in different signal sections at the receiving end, and obtains the CFOs of all users after extracting the phase-angles. With an economizing signal bandwidth and lower computation complexity, the presented algorithm is suitable for CFO tracking in the fine CFO estimation phase. The simulation results show that the algorithm can meet the CFO estimation requirements in orthogonal frequency division multiplexing （OFDM） systems when using the hidden pilots with comparatively low average power.