华南理工大学学报(自然科学版) ›› 2015, Vol. 43 ›› Issue (9): 39-46.doi: 10.3969/j.issn.1000-565X.2015.09.007

• 电子、通信与自动控制 • 上一篇    下一篇

载波频偏对 OFDM AF 中继系统性能的影响

李巨虎1  聂娟2   

  1. 1. 北京林业大学 信息学院,北京 100083; 2. 北京农学院 计算机与信息工程学院,北京 102206
  • 收稿日期:2015-03-16 修回日期:2015-04-23 出版日期:2015-09-25 发布日期:2015-09-07
  • 通信作者: 李巨虎(1978-),男,博士,讲师,主要从事物联网、无线通信等研究. E-mail:lijuhu@ bjfu.edu.cn
  • 作者简介:李巨虎(1978-),男,博士,讲师,主要从事物联网、无线通信等研究.
  • 基金资助:
    北京林业大学中央高校基本科研业务费专项资金资助项目(TD2014-01);北京市教委科技面上资助项目
    (KM20151002)

Effect of Carrier Frequency Offsets on Performance of OFDM AF Relay System

Li Ju-hu1  Nie Juan2    

  1. 1. School of Information,Beijing Forestry University,Beijing 100083,China; 2. College of Computer and Information Engineering,Beijing University of Agriculture,Beijing 102206,China
  • Received:2015-03-16 Revised:2015-04-23 Online:2015-09-25 Published:2015-09-07
  • Contact: 李巨虎(1978-),男,博士,讲师,主要从事物联网、无线通信等研究. E-mail:lijuhu@ bjfu.edu.cn
  • About author:李巨虎(1978-),男,博士,讲师,主要从事物联网、无线通信等研究.
  • Supported by:
    Supported by the General Program of Beijing Committee of Education Science and Technology(KM20151002)

摘要: 研究了存在载波频偏的正交频分复用( OFDM) 放大转发( AF) 中继系统的中断概率和误码率. 首先给出了存在载波频偏时系统信噪比及其概率分布,然后推导出瑞利信道中存在载波频偏时系统中断概率和误码率的闭合表达式. 为了更加直观,文中还给出了大信噪比时系统中断概率和误码率的错误下界,并通过数值仿真来验证理论分析的正确性.理论分析和仿真结果表明: 存在载波频偏时,即使在大信噪比情形下系统的中断概率和误码率并不趋于 0,而是趋于错误下界; OFDM AF 系统对载波频偏很敏感,随着信噪比的增大,系统性能随着载波频偏的增大迅速变差.

关键词: 放大转发, 正交频分复用, 载波频偏, 中断概率, 误码率

Abstract: This paper deals with the bit error rate (BER) and outage probability of a dual hop OFDM AF relay sys-
tem in the presence of carrier frequency offsets (CFO). First,the signal-to-noise ratio (SNR) of the system and its probability distribution are put forward in the presence of CFO,and then the close-form expressions of the BER and outage probability of the system are derived with CFO in Rayleigh fading channels. In order to provide more insights,the error floors of the BER and outage probability of the system are also obtained. Moreover,a theoretical analysis is proved to be correct by simulation. The theoretical analysis and simulation results indicate that,in the presence of CFO,the BER and outage probability of the system tend to be the error floor but not zero even at a high SNR,and that the performance of OFDM AF relay system is very sensitive to the CFO,and the system performance gets worse rapidly with the increases of the CFO and the SNR.

Key words: amplify-and-forward, orthogonal frequency division multiplexing, carrier frequency offsets, outage
probability,
bit error rate