Acta Metallurgica Sinica(English letters) ›› 2007, Vol. 14 ›› Issue (2): 94-98.doi: 1005-8885 (2007) 02-0094-05

• B3G • 上一篇    下一篇

Estimation of time-varying channels for pilot-assisted OFDM systems

唐甜;DENG Gang;JIANG Jun   

  1. Beijing University of Posts and Telecommunications
  • 收稿日期:2006-11-30 修回日期:1900-01-01 出版日期:2007-06-30

Estimation of time-varying channels for pilot-assisted OFDM systems

TANG Tian;DENG Gang;JIANG Jun   

  1. Beijing University of Posts and Telecommunications
  • Received:2006-11-30 Revised:1900-01-01 Online:2007-06-30

摘要:

Orthogonal frequency division multiplexing (OFDM) systems encounter performance degradations because of the time-varying (TV) channels common in wireless environments. The channel variations within one OFDM symbol introduce intercarrier interference. In this case, the frequency domain channel matrix is no longer diagonal, hence the corresponding channel estimation is challenging. In this article, two novel TV channel estimation approaches are proposed for the pilot-assisted OFDM systems, where the channel is approximated by the high-order linear model or the piece-wise linear model in time domain. The least square estimation is derived for the two kinds of channel approximations. The simulation is performed based on realistic TV channels with a fairly high Doppler spread. The results show the significant decreasing of the estimation mean square error using the proposed approaches.

关键词:

OFDM;pilot-assisted modulation;TV channels; channel estimation

Abstract:

Orthogonal frequency division multiplexing (OFDM) systems encounter performance degradations because of the time-varying (TV) channels common in wireless environments. The channel variations within one OFDM symbol introduce intercarrier interference. In this case, the frequency domain channel matrix is no longer diagonal, hence the corresponding channel estimation is challenging. In this article, two novel TV channel estimation approaches are proposed for the pilot-assisted OFDM systems, where the channel is approximated by the high-order linear model or the piece-wise linear model in time domain. The least square estimation is derived for the two kinds of channel approximations. The simulation is performed based on realistic TV channels with a fairly high Doppler spread. The results show the significant decreasing of the estimation mean square error using the proposed approaches.

Key words:

OFDM; pilot-assisted modulation; TV channels;channel estimation

中图分类号: