Non-Data Aided EM-Based Channel Estimation for OFDM Systems with Time-Varying Fading Channels

  • Erdal Panayirci
  • Hakan A. Çirpan

Abstract

In this paper, a computationally efficient algorithm is presented for maximum a posteriori (MAP) channel estimation for OFDM systems employing M-PSK modulation scheme with additive Gaussian noise, based on the Expectation Maximization (EM) method. A non-data-aided scheme is considered for the estimation of a multipath time-varying channel by averaging over the M-PSK signal constellation. For this, an EM algorithm is derived which estimates the complex channel parameters of each subcarriers iteratively in frequency domain and which converges to the true MAP estimation of the unknown channel. The algorithm requires a convenient representation of the discrete multipath fading channel based on the Karhunen-Loeve orthogonal expansion. The algorithm is applied to the QPSK modulated OFDM systems and efficiency of the method proposed is shown by the computer simulations.

Keywords

Fading Channel Channel Estimation Channel State Information ExpectatIon MaXI1111zatlon Algorithm Pilot Symbol 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer Science+Business Media New York 2002

Authors and Affiliations

  • Erdal Panayirci
    • 1
    • 2
  • Hakan A. Çirpan
    • 1
    • 2
  1. 1.Department of Electronics EngineeringISIK UniversityMaslakTurkey
  2. 2.Department of Electrical-Electronics EngineeringIstanbul UniversityAvcilarTurkey

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