Journal of South China University of Technology (Natural Science Edition) ›› 2011, Vol. 39 ›› Issue (7): 63-69.doi: 10.3969/j.issn.1000-565X.2011.07.011

• Electronics, Communication & Automation Technology • Previous Articles     Next Articles

Design of Pilot Signals in OFDM Systems

Yang Wei1,2  Sun Le1,2  Xu Chang-long2   

  1. 1. State Key Laboratory of Rail Traffic Control and Safety,Beijing Jiaotong University,Beijing 100044,China;2. National Mobile Communications Research Laboratory,Southeast University,Nanjing 210096,Jiangsu,China
  • Received:2010-08-09 Revised:2011-04-02 Online:2011-07-25 Published:2011-06-03
  • Contact: 杨维(1964-) ，男，博士，教授，主要从事无线宽带通信技术研究． E-mail:wyang@ bjtu.edu.cn
  • About author:杨维(1964-) ，男，博士，教授，主要从事无线宽带通信技术研究．
  • Supported by:

    国家科技重大专项( 2009ZX03003-005) ; 轨道交通控制与安全国家重点实验室自主研究课题( RCS2009ZT014) ; 东南大学移动通信国家重点实验室开放基金资助项目( 2010D11)

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Abstract:

This paper deals with the channel estimation technology applied to orthogonal frequency division multiplexing ( OFDM) systems and proposes a novel method to design the optimal pilot pattern. In this method,first,the spacing in the time and the frequency domains between two pilot symbols are determined respectively according to the maximum multi-path delay and Doppler frequency shift. Then,all possible pilot patterns are listed by using
the exhaustive method. Finally,the optimal pilot pattern is obtained according to the mean square error between the estimated and the actual channels. In addition,the proposed method is applied to a long-term evolution ( LTE) system to verify its correctness and effectiveness,and the superiority of the optimal pilot pattern is verified by simulation curves. From the simulated results,it is found that,as compared with the system using the original LTE pilot pattern,the system using the optimal pattern is of higher BER ( Bit Error Rate) performance under the Vehicular Test A channel.

Key words: orthogonal frequency division multiplexing, pilot design, exhaustive method, mean square error, longterm evolution