恒包络MIMO-OFDM系统中的盲载波同步  

Blind Frequency Synchronization for MIMO-OFDM Systems with Constant-Modulus

作　　者：姜雪峰[1] 余松煜[1] 陈容[1] 

机构地区：[1]上海交通大学电子工程系,上海200030

出　　处：《电讯技术》2006年第4期41-44,共4页Telecommunication Engineering

基　　金：国家高技术研究发展计划(863计划)重大专项项目(2003AA123310)

摘　　要：盲频偏估计不占频谱资源,但性能欠佳。为了提高性能,在盲估计算法中引入多天线,推导出恒包络M IMO-OFDM系统中盲估计的代价函数,充分利用多天线的分集增益来改善性能,仿真表明性能确有明显提高。当子载波满载时,该算法的约束条件之一保护边带将不复存在,估计的频偏只能局限于小数范围内。运用在频域插入少量导频的半盲估计算法,并利用一种导频方案———空载导频,在频率利用率不损失的情况下,扩大了频偏的搜索范围。仿真发现该半盲算法即使在低信噪比下也能很好地估计频偏。Frequency efficiency improvement can be obtained while the performance will be degraded using blind estimation algorithm. In this paper, the cost function of blind estimator for MIMO - OFDM systems is provided. Making use of the space diversity, the perfOrmance can be improved. Unfortunately when all carders in the OFDM symbol are occupied, the condition for this algorithm does not exist, and then the scope of frequency offset estimation is confined to fraction. This problem is solved by inserting a bit of frequency domain pilots. Two kinds of pilot schemes are used and They perform very well even under low SNR without frequency efficiency lost.

关 键 词：MIMO-OFDM 同步 恒包络 多天线 载波频偏估计 盲估计 

分 类 号：TN914.5[电子电信—通信与信息系统]