OFDM系统中基于导符号和判决数据的频偏估计  

The Frequency Offset Estimation Algorithm for OFDM Systems Based on Pilot Symbols and Decision Data

作　　者：郑来波[1] 袁东风[1] 胡健栋[2] 

机构地区：[1]山东大学信息科学与工程学院,济南250100 [2]北京邮电大学电信工程学院,北京100876

出　　处：《北京邮电大学学报》2005年第5期21-24,共4页Journal of Beijing University of Posts and Telecommunications

摘　　要：正交频分复用系统中为进行信道估计通常在OFDM符号中插入导符号,对利用这些导符号进行频偏估计的方法做了进一步研究.在时域和频域都重新推导了估计结果,经过合理近似,得到时域最大似然估计的近似解;在频域推导了另一种形式的似然函数,得出最大似然估计的解析表达式.新算法降低了计算量,提高了频偏估计精确度.同时,对利用导符号并结合判决数据进行频偏估计的算法也做了研究,判决数据的使用可以使估计结果更加精确.In orthogonal frequency division multiplexing systems, the pilot symbols are often inserted for channel estimation. The frequency offset estimation algorithm using these pilot symbols was further analyzed. By modifying the derivation procedures both in time domain and frequency domain, and by the proper approximation, the approximate maximum likelihood estimation result in time domain was derived. Meanwhile, a different form of likelihood function in frequency domain was derived, and analytical estimation result was also given. The new algorithm decreases the computational complexity greatly, and increases the accuracy of the estimation greatly. The estimation algorithm using pilot symbols together with the decision data was also analyzed, and the accuracy of the estimation result can be improved by utilizing the decision data.

关 键 词：正交频分复用系统 载波频率偏移 最大似然 跟踪 

分 类 号：TN914.3[电子电信—通信与信息系统]