Title :
Pilot-symbol-aided channel estimation for OFDM in wireless systems
Author_Institution :
AT&T Labs.-Res., Red Bank, NJ, USA
fDate :
7/1/2000 12:00:00 AM
Abstract :
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
Keywords :
OFDM modulation; dispersive channels; fading channels; land mobile radio; least mean squares methods; parameter estimation; Doppler frequencies; MMSE; OFDM; dispersive fading channels; hilly-terrain channels; minimum mean-square error; noise impairment; orthogonal frequency division multiplexing; performance degradation; pilot-symbol-aided channel estimation; signal-to-noise ratios; urban channels; wireless systems; Channel estimation; Dispersion; Error analysis; Fading; Frequency estimation; Noise robustness; OFDM; Parameter estimation; Signal to noise ratio; Statistics;
Journal_Title :
Vehicular Technology, IEEE Transactions on
