摘要
OFDM系统对定时和载波频率偏差极其敏感,为了解决OFDM符号定时同步和载波频率同步的问题,采用基于循环前缀的最大似然估计算法,分析了对OFDM系统同步产生影响的三个主要因素,详细推导了基于循环前缀的最大似然估计算法,并针对最大似然估计算法在不同信道下的性能以及循环前缀长度对同步性能的影响进行了仿真分析,仿真结果对OFDM系统中循环前缀长度的选取具有指导意义。
OFDM systems are extrernely sensitive to timing offset and carrier frequency offset. In order to solve the problems of OFDM symbols timing synchronization and carrier frequency synchronization, the maximum likelihood estimation algorithm based on cyclic prefix was adopted. Three main factors affecting the synchronization of OFDM systems were analyzed and the maximum likelihood estimation algorithm based on cyclic prefix was deduced in detail. The performance of maximum likelihood estimation algorithm in different channels and the influence of the length of cyclic prefix on the synchronization performance were simulated and analyzed. The sinaulation results have guiding significance for the selection of the length nfcyclic prefix in OFDM systems.
出处
《移动通信》
2017年第21期42-46,共5页
Mobile Communications
关键词
OFDM
最大似然算法
循环前缀
定时估计
频偏估计
OFDM
maximum likelihood estimation algorithm
cyclic prefix
timing offset estimation
frequcncy offset estimation
