J4 ›› 2010, Vol. 37 ›› Issue (4): 758-763.doi: 10.3969/j.issn.1001-2400.2010.04.031

• Original Articles • Previous Articles     Next Articles

Channel estimation method for OFDMA systems over fast time-varying channels

LI Dan1,2;FENG Sui-li1;YE Wu1;ZHUANG Hong-cheng3   

  1. (1. School of Electronic and Info. Eng., South China Univ. of Tech., Guangzhou  510640, China;
    2. School of Computer Sci., Shaoguan Univ., Shaoguan  512005, China;
    3. Pre-research Dept., Huawei Tech. CO. Ltd, Shenzhen  518100, China)
  • Received:2009-04-15 Online:2010-08-20 Published:2010-10-11
  • Contact: LI Dan E-mail:d.li@mail.scut.edu.cn

Abstract:

Current channel estimation (CE) schemes for OFDMA systems track channel variations symbol by symbol result in ICI when the channel is Time-varying (TV) in one symbol period. However, conventional TV CE methods for OFDM systems need optimal even-pilots to track channel time variations in one symbol period. For practical OFDMA systems, the required even pilot tone is not satisfied. In this paper, we present a pilot-assisted CE method for practical OFDMA systems in TV channels, which is performed in the frequency-domain, avoiding time-domain transformations and does not need even-spaced pilots. The frequency-domain transmission function is employed to estimate channel variations over one OFDMA symbol period. Simulation results show that the proposed method outperforms current OFDMA CE schemes in terms of the symbol-error-rate (SER) and Mean Square Error (MSE).

Key words: OPDM, OFDMA, TV channels, channel estimation, uneven pilot, linear model