Robust channel estimation for the OFDM-based WLAN systems with imperfect synchronization
Wireless Personal Communications: An International Journal
Time-frequency modeling and estimation of wireless OFDM channels
ICCOMP'05 Proceedings of the 9th WSEAS International Conference on Computers
DFT-based channel estimation with symmetric extension for OFDMA systems
EURASIP Journal on Wireless Communications and Networking - Special issue on OFDMA architectures, protocols, and applications
A fast LMMSE channel estimation method for OFDM systems
EURASIP Journal on Wireless Communications and Networking - Special issue on OFDMA architectures, protocols, and applications
Improved ML Channel Estimation for Uplink MC-CDMA Systems in Closely Spaced Multipath Channels
Wireless Personal Communications: An International Journal
Dynamic pilot carriers assignment for DVB-H system
WOCN'09 Proceedings of the Sixth international conference on Wireless and Optical Communications Networks
Nonquiet primary user detection for OFDMA-based cognitive radio systems
IEEE Transactions on Wireless Communications
Blind estimation of channel length for OFDM systems
WiCOM'09 Proceedings of the 5th International Conference on Wireless communications, networking and mobile computing
A Krylov subspace based low-rank channel estimation in OFDM systems
Signal Processing
Analysis of interpolated channel estimation for mobile OFDM systems
IEEE Transactions on Communications
Pilot-aided multicarrier channel estimation via MMSE linear phase-shifted polynomial interpolation
IEEE Transactions on Wireless Communications
Semi-blind most significant tap detection for sparse channel estimation of OFDM systems
IEEE Transactions on Circuits and Systems Part I: Regular Papers
Time-varying channel identification and prediction in OFDM systems using 2-D frequency estimation
MILCOM'06 Proceedings of the 2006 IEEE conference on Military communications
Channel estimation for wireless OFDM communication systems
SIP'06 Proceedings of the 5th WSEAS international conference on Signal processing
Tracking time-varying correlated underwater acoustic channels in the signal subspace
Proceedings of the Eighth ACM International Conference on Underwater Networks and Systems
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In orthogonal frequency division multiplexing (OFDM) systems over fast-varying fading channels, channel estimation and tracking is generally carried out by transmitting known pilot symbols in given positions of the frequency-time grid. The traditional approach consists of two steps. First, the least-squares (LS) estimate is obtained over the pilot subcarriers. Then, this preliminary estimate is interpolated/smoothed over the entire frequency-time grid. In this paper, we propose to add an intermediate step, whose purpose is to increase the accuracy of the estimate over the pilot subcarriers. The presented techniques are based on the observation that the wireless radio channel can be parametrized as a combination of paths, each characterized by a delay and a complex amplitude. The amplitudes show fast temporal variations due to the mobility of terminals while the delays (and their associated delay-subspace) are almost constant over a large number of OFDM symbols. We propose to track the delay-subspace by a subspace tracking algorithm and the amplitudes by the least mean square algorithm (or modifications of the latter). The approach can be extended to multiple input multiple output OFDM or multicarrier code-division multiple-access systems. Analytical results and simulations prove the relevant benefits of the novel structure.