Pilot-symbol-aided channel estimation for OFDM in wireless systems

In this paper, we investigate pilot-symbol-aided parameter estimation for orthogonal frequency division multiplexing (OFDM) systems. We first derive a minimum mean-square error (MMSE) pilot-symbol-aided parameter estimator. Then, we discuss a robust implementation of the pilot-symbol-aided estimator that is insensitive to channel statistics. From the simulation results, the required signal-to-noise ratios (SNRs) for a 10% word error rate (WER) are 6.8 dB and 7.3 dB for the typical urban (TU) channels with 40 Hz and 200 Hz Doppler frequencies, respectively, and they are 8 dB and 8.3 dB for the hilly-terrain (HT) channels with 40 Hz and 200 Hz Doppler frequencies, respectively. Compared with the decision-directed parameter estimator, the pilot-symbol-aided estimator is highly robust to Doppler frequency for dispersive fading channels with noise impairment even though it has some performance degradation for systems with lower Doppler frequencies.

[1]  Babak Daneshrad,et al.  Clustered OFDM with transmitter diversity and coding , 1996, Proceedings of GLOBECOM'96. 1996 IEEE Global Telecommunications Conference.

[2]  J. Cavers.  An analysis of pilot symbol assisted modulation for Rayleigh fading channels (mobile radio) , 1991 .

[3]  Fredrik Tufvesson,et al.  Pilot assisted channel estimation for OFDM in mobile cellular systems , 1997, 1997 IEEE 47th Vehicular Technology Conference. Technology in Motion.

[4]  W. C. Jakes,et al.  Microwave Mobile Communications , 1974 .

[5]  Geoffrey Ye Li,et al.  Adaptive antenna arrays for OFDM systems with cochannel interference , 1999, IEEE Trans. Commun..

[6]  H.H. H'mimy.  Channel estimation based on coded pilot for OFDM , 1997, 1997 IEEE 47th Vehicular Technology Conference. Technology in Motion.

[7]  Per Ola Börjesson,et al.  OFDM channel estimation by singular value decomposition , 1996, Proceedings of Vehicular Technology Conference - VTC.

[8]  A. W. M. van den Enden,et al.  Discrete Time Signal Processing , 1989 .

[9]  Irving Kalet,et al.  The multitone channel , 1989, IEEE Trans. Commun..

[10]  J. H. Winters,et al.  Spatial-temporal equalization for IS-136 TDMA systems with rapid dispersive fading and cochannel interference , 1999 .

[11]  Leonard J. Cimini,et al.  Analysis and Simulation of a Digital Mobile Channel Using Orthogonal Frequency Division Multiplexing , 1985, IEEE Trans. Commun..

[12]  S.K. Wilson,et al.  On channel estimation in OFDM systems , 1995, 1995 IEEE 45th Vehicular Technology Conference. Countdown to the Wireless Twenty-First Century.

[13]  Robert Bregovic,et al.  Multirate Systems and Filter Banks , 2002 .

[14]  Sirikiat Lek Ariyavisitakul,et al.  Channel estimation for OFDM systems with transmitter diversity in mobile wireless channels , 1999, IEEE J. Sel. Areas Commun..

[15]  R. Mersereau,et al.  The processing of periodically sampled multidimensional signals , 1983 .

[16]  John G. Proakis,et al.  Probability, random variables and stochastic processes , 1985, IEEE Trans. Acoust. Speech Signal Process..

[17]  Ye Li,et al.  Transmitter diversity for OFDM systems with mobile wireless channels , 1998, IEEE GLOBECOM 1998 (Cat. NO. 98CH36250).

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

[19]  Patrick Robertson,et al.  Pilot-symbol-aided channel estimation in time and frequency , 1997 .

[20]  Geoffrey Ye Li,et al.  Transmitter diversity for OFDM systems and its impacts on high-rate wireless networks , 1999, 1999 IEEE International Conference on Communications (Cat. No. 99CH36311).

[21]  Alberto Morello,et al.  CD3-OFDM: a novel demodulation scheme for fixed and mobile receivers , 1996, IEEE Trans. Commun..

[22]  Patrick Robertson,et al.  Two-dimensional pilot-symbol-aided channel estimation by Wiener filtering , 1997, 1997 IEEE International Conference on Acoustics, Speech, and Signal Processing.

[23]  Geoffrey Ye Li,et al.  Robust channel estimation for OFDM systems with rapid dispersive fading channels , 1998, IEEE Trans. Commun..