一种改进的基于DFT的OFDM信道估计算法  

An Improved OFDM Channel Estimation Algorithm Based on DFT

作　　者：焦明伟[1] 贾振红[1] 覃锡忠[1] 李涛 赵君凯 

机构地区：[1]新疆大学信息科学与工程学院,新疆乌鲁木齐830046 [2]中国移动通信集团新疆有限公司,新疆乌鲁木齐830091

出　　处：《通信技术》2010年第8期117-120,共4页Communications Technology

基　　金：教育部新世纪优秀人才支持计划项目(编号:NCET-05-0897)

摘　　要：传统的DFT信道估计算法计算复杂度比MMSE算法低,性能比LS算法好。但是它只消除了信道冲击响应中循环前缀长度之外的噪声,而循环前缀长度以内的噪声并没有进行任何抑制,从而影响了算法的性能,说明性能存在提高的空间。对传统的DFT信道估计算法略加改进,仅仅在循环前缀长度内引入阈值门限,通过阈值门限进行阈值处理,就可以进一步消除噪声的影响。仿真表明:改进后的算法性能明显优于原算法,具有很好的实用价值。Traditional DFT-based channel estimator for OFDM systems has lower computational complexity than MMSE channel estimators, and better performance than LS channel estimators. However, the traditional DFT-based channel estimator removes only the noise in the channel impulse response （CIR） beyond the length of the cyclic prefix （CP）, while the noise within the length of CP is not suppressed at all, affecting the performance of the algorithm, and indicating that there is certain space for improving its performance. The traditional channel estimator is fairly improved and proposed. Only by introducing a decision threshold into the length of CP, the influence of the noise could be further removed by threshold processing. Simulation results show that the improved algorithm is superior to the original algorithm, and thus is of practical application value.

关 键 词：正交频分复用技术 离散傅里叶变换 信道估计 阈值门限 

分 类 号：TN911.23[电子电信—通信与信息系统]