Parametric Channel Estimation by Exploiting Hopping Pilots in Uplink OFDMA

This paper proposes a parametric channel estimation algorithm applicable to uplink of OFDMA systems with pseudo-random subchannelization. It exploits the hopping pilots to facilitate ESPRIT to estimate the delay subspace of the multipath fading channel, and utilizes the global pilot tones to interpolate on data subcarriers. Hence, it outperforms the traditional local channel interpolators considerably.Comment: 5 pages, 3 figures, Appeared in IEEE PIMRC'0

Exploiting Hopping Pilots for Parametric Channel Estimation in OFDM Systems

Abstract—In this letter, we investigate the effect of hopping pilots on the parametric channel estimation in orthogonal frequency-division multiplexing (OFDM) systems. Channel estimation algorithms based on parametric channel modeling require the multipath delays to be estimated at the receiver. The use of a fixed pilot pattern leads to longer training overhead in multipath delay estimation for slow fading channels. However, if hopping pilot patterns are available, then we show that the normalized mean-squared error (NMSE) convergence rate of the channel estimates can be significantly improved. We also show that hopping pilot patterns in OFDM systems effectively allow the eigenvectors of the delay subspace (of the autocorrelation matrix) to be estimated faster. Simulation results are provided to show the faster convergence rate of the NMSE for the hopping pilot pattern over the fixed pilot pattern. Index Terms—Fading multipath channels, hopping pilots, orthogonal frequency-division multiplexing (OFDM), parametric estimation, subspace channel estimation. I