LTE系统中一种改进的频偏估计代价算法

Improved cost-function CFO estimation algorithm in LTE system

时频同步是LTE下行过程的重要过程,而载波频偏估计是获得频率同步的重要步骤,本文重点分析研究了LTE下行的频偏估计的基于CP(循环前缀)相关的ML算法和cost-function(代价函数)算法,针对后者在要求误差较小时计算量大的缺点,提出一种改进的算法。将小数倍频偏分为两部分,利用CP快速估计出缀εcp的大概范围,将其补偿回去,再利用代价算法估计出剩余部分缀εcost。仿真结果表明,通过此方法可以在保证代价算法准确性的基础上,减少代价算法大约80%的计算量。

Time and frequency synchronization are of fundamental importance for downlink of Long Term Evolution（LTE）,carrier frequency offset（CFO）estimation is an important step to achieve frequency synchronization. This paper researches CFO estimation algorithms which are the Max-Likelihood estimation based CP correlation and cost-function algorithms.Aiming at the cost-function algorithms has the shortcoming that needs a large number of calculations, this paper proposes an improved algorithms. CFO is divided into two parts, is estimated by CP correlation using its less calculations. Then,缀cp! is compensated to rcving data in time domain, the leaving CFO 缀cost! is estimated by cost-function algorithms. The simulations show that,the improved algorithms has reduced complexity by about 80% while insuring the veracity of costfunction algorithms.