Channel equalization using one-tap DFE for wireless OFDM systems with ICI and ISI

In an OFDM system for wireless communications, a guard interval longer than channel delay has to be used to avoid interchannel interference (ICI) and intersymbol interference (ISI), and so the multiplexed subchannels can be decoupled by the discrete Fourier transform (DFT). However, this ICI- and ISI-free OFDM system reduces the efficiency of bandwidth usage and prevents the use of sufficient statistics in channel equalization. In this paper, we consider the OFDM system that achieves one hundred percent efficiency of bandwidth usage and uses sufficient statistic. A one-tap decision feedback equalizer (DFE) is proposed. It is demonstrated that though occupying narrower bandwidth, the one-tap DFE based, ICI and ISI OFDM system achieves lower symbol error rate and higher mutual information between input of decision device and transmitted symbols.

[1]  N. Al-Dhahir,et al.  Optimum finite-length equalization for multicarrier transceivers , 1994, 1994 IEEE GLOBECOM. Communications: The Global Bridge.

[2]  Dipankar Raychaudhuri,et al.  WATMnet: A Prototype Wireless ATM System for Multimedia Personal Communication , 1997, IEEE J. Sel. Areas Commun..

[3]  S. Weinstein,et al.  Data Transmission by Frequency-Division Multiplexing Using the Discrete Fourier Transform , 1971 .

[4]  Raymond A. Heising Modulation Methods , 1962, Proceedings of the IRE.

[5]  Charles E. Rohrs,et al.  Impulse response shortening for discrete multitone transceivers , 1996, IEEE Trans. Commun..

[6]  J.A.C. Bingham,et al.  Multicarrier modulation for data transmission: an idea whose time has come , 1990, IEEE Communications Magazine.

[7]  D. Slepian,et al.  On bandwidth , 1976, Proceedings of the IEEE.

[8]  Kaveh Pahlavan,et al.  Transmission Techniques for Radio LAN's - A Comparative Performance Evaluation Using Ray Tracing , 1996, IEEE J. Sel. Areas Commun..

[9]  M. de Courville,et al.  Blind equalization of OFDM systems based on the minimization of a quadratic criterion , 1996, Proceedings of ICC/SUPERCOMM '96 - International Conference on Communications.