摘要
在相干正交频分复用(OFDM)系统中为跟踪多径信道的实时变化通常在时频网格上插入导符号来进行信道估计.对利用这些导符号结合判决数据进行频率跟踪的算法作了进一步的研究.在时域和频域都重新推导了频偏的估计结果,经过合理近似,得到了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,得出了最大似然估计的解析表达式.新的频率跟踪算法降低了计算量,提高了频率同步的精确度.
In coherent orthogonal frequency division multiplexing systems, the pilot symbols are often inserted into time-frequency grid to tracking the real time variation of the channel response. The frequency synchronization 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 the analytical estimation result was also given. The new tracking algorithm decreases the computational complexity greatly, and increases the accuracy of the frequency synchronization.
出处
《电子学报》
EI
CAS
CSCD
北大核心
2006年第1期127-130,共4页
Acta Electronica Sinica
关键词
OFDM系统
载波频率偏移
最大似然
跟踪
OFDM systems
carrier frequency offset
maximum likelihood
tracking
