一种基于周期失配序列的OFDM时变信道估计 .pdfVIP

学兔兔 总第48卷 第542期 电测与仪表 2011年 第02期 Electrical M easurement Instrumcntation 一 种基于周期失配序列的OFDM时变信道估计术 ， 王凤娟，肖丽萍，于丰彩 (燕山大学信息科学与工程学院，河北秦皇岛066004) 摘要：提出了一种将周期失配序列插入到OFDM符号中作为训练序列进行信道估计的新方法。由于周期序列 ． 的能量主要集中在少数几个导频点上，所以将周期失配序列进行FFT变换后插入到OFDM符号中，对接收到的 少数几个导频点上的失配序列进行IFFT变换后与失配滤波器循环移位序列做相关运算，得到信道冲击响应。 本文在多径时变信道下，对新算法和已有算法进行了仿真。结果表明，新算法在计算复杂度低的情况下，有效 降低了信道的MSE值和BER值，特别是在OFDM系统子载波数多且SNR低的情况下，性能改善更加明显。 关键词：OFDM；信道估计；周期序列；失配序列 中图分类号：TM76 文献标识码：A 文章编号：1001—1390(2011)02—0050—04 Channel Estimation for Time—Varing Channel Based on Periodic Mismatched Sequence in OFDM Systems WANG Feng—juan，XIAO Li～ping，YU Feng—cai (College of Information Science and Engineering，Yanshan University，Qinhuangdao 066004，Hebei，China) Abstract：A new approach which using to add periodic mismatched sequence to OFDM signals as training sequence to channel estimation in OFDM systerns is proposed．The energy of periodic sequence mainly concentrates in a few pilot points，SO after FFT transformation，periodic mismatched sequence is inserted into OFDM signals．To calculate the cross—Correlation between the received mismatched sequence in a few pilot points and the circular shifted mismatch ， filter coefficient solves the channel impulse response．Comparison has been done between the proposed algorithm and the existing algorithm in the time—varying muhipath channe1．Simulation results show that the new algorithm effective- ly reduees the value of MSE