Fast-fading channel estimator using DCT and simplified kalman filter

JORGE SCHMIDT; JUAN COUSSEAU; RISTO WICHMAN; FERNANDO GREGORIO

Helsinki

Workshop; Signal Processing Advances in Wireless Communications, 2007. SPAWC 2007. IEEE 8th Workshop on; 2007

Helsinki University of Technology

We present a novel channel estimator for fading channels using basis function approximations and Kalman filtering. The proposal results in a low complexity estimator that is robust to the shape of the channel Doppler spectrum and allows different Doppler spectra for each channel coefficient in a frequency-selective scenario. The estimator is based on the description of channel variations via truncated discrete cosine transform (DCT). We show that DCT can be approximated by a set of linear narrowband passband filters that can be inserted into a Kalman filter formulation that track a set of decoupled parameters. This estimator attains close to perfect channel knowledge performance with only 1% training symbols in a data frame with Doppler frequencies up to 0.8 times the frame frequency.