北京大学学报(自然科学版)

一种基于PN序列的上行多用户OFDM系统载波频偏估计算法

任术波,郭俊奇,吴建军,项海格   

  1. 北京大学电子学系卫星与无线通信实验室,北京100871;
  • 收稿日期:2009-02-27 出版日期:2009-11-20 发布日期:2009-11-20

A PN-Based Carrier Frequency Offset Estimation Algorithmfor Multiuser OFDM Uplink

REN Shubo, GUO Junqi, WU Jianjun, XIANG Haige   

  1. Satellite and Wireless Communication Laboratory, Department of Electronics, Peking University, Beijing 100871;
  • Received:2009-02-27 Online:2009-11-20 Published:2009-11-20

摘要: 针对多用户正交频分复用(OFDM) 系统上行链路中的载波频偏估计问题, 提出一种基于伪噪声(PN)序列的载波频偏(CFO)估计算法。该算法将不同相位的PN序列作为各个用户的训练序列, 利用训练序列良好的自相关性估计出存在CFO 情形下不同用户的信道参数, 再根据两个训练周期内信道参数的相位变化获得各用户的CFO估值。理论分析和仿真结果表明本算法具有优 良的估计性能。

关键词: 多用户OFDM系统, 伪噪声(PN)序列, 载波频偏(CFO)估计

Abstract: The authors propose a pseudo-noise (PN) sequence-based carrier frequency offset (CFO) estimation algorithmfor multiuser OFDMuplink. In the proposed algorithm, a PN sequence and its circular-shifting versions are considered as training sequences for different users, and then channel parameters with CFO factors from each user to a central base station can be estimatedby virtue of autocorrelation characteristic of the PN sequence. Finally all users’CFO estimates can be acquired simultaneously by calculating channel phase-angle difference between two training periods. The simulation result shows that the proposed algorithm achieves better estimation performance.

Key words: multiuser OFDM, pseudo-noise (PN) sequence, carrier frequency offset (CFO) estimation

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