A refined channel estimation method for STBC/OFDM systems in high-mobility wireless channels

Meng Lin Ku*, Chia-Chi Huang

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

16 Scopus citations

Abstract

In this paper, we investigate channel estimation for orthogonal frequency division multiplexing (OFDM) systems with space-time block code (STBC) in mobile wireless channels. Our proposed method consists of two-stage processing and is developed on the basis of the classical discrete Fourier transform (DFT)-based channel estimation method. In the initialization stage, we employ a multipath interference cancellation technique to estimate multipath delays and multipath complex gains. In the tracking stage, we develop a refined decision-feedback (DF) DFT-based channel estimation method in which a few pilot tones inserted in OFDM data symbols are applied to form an optimal gradient vector at the first iteration such that the error propagation effect is mitigated. In order to reduce computational complexity, an approximate weighting matrix is adopted to avoid matrix inversion. We demonstrate the proposed method through computer simulation of an STBC/OFDM system with two transmit antennas and a single receive antenna. The results show that our method outperforms the classical DFT-based method, the STBC-based minimum mean square error (MMSE) method, and the Kalman filtering method as well, and that significant signal-to-noise ratio (SNR) performance improvement can be achieved, especially when a high-level modulation scheme, e.g. 16QAM, is adopted in high-mobility environments.

Original languageEnglish
Article number4684607
Pages (from-to)4312-4320
Number of pages9
JournalIEEE Transactions on Wireless Communications
Volume7
Issue number11
DOIs
StatePublished - 1 Nov 2008

Keywords

  • Channel estimation
  • IEEE 802.16e
  • Multiple-input multiple-output systems
  • Orthogonal frequency division multiplexing
  • Space-time coding

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