OFDM系统中基于循环前缀的频偏估计算法

摘要

OFDM 是利用多个正交的子载波并行传输数据来提高传输效率的一种新技术，具有频谱利用率高、抗多径衰落、抗窄带干扰等优点，被视为第四代移动通信中的关键技术。为保证子载波之间的正交性，对载波频偏估计和补偿成为OFDM技术研究热点。本文提出了一种基于循环前缀的频偏估计算法，通过把循环前缀分成四个小序列，对前三个序列单独进行相位差计算，对第四个序列进行均值估计，最终推导出频偏的估计值。仿真结果表明，本文算法在减小计算量的情况下，提高了频偏估计精度。%OFDM is a new technology that is used to send data via multiple orthogonal subcarriers in a parallel way to improve transmit efficiency.It is a key technology for the 4G because of its advantages of anti multipath fading,high spectrum utilization and resistance to narrowband interference.To ensure the orthogonal between subcarriers,frequency offset estimation and compensation is a hot topic for OFDM technology.This paper proposes a frequency offset estima-tion algorithm based on cyclic prefix in OFDM by dividing the cyclic prefix into four parts and make phase difference calculation for the first three parts separately,and later make mean estimation on the fourth part.Simulation results show that the proposed algorithm improves the accuracy of frequency offset estimation in the case of reducing the computa-tional amount.