EM-based Semi-Blind Estimation of Time-Varying Channels
Original Publication Date: 2003-Jan-13
Included in the Prior Art Database: 2003-Jan-13
OFDM systems traditionally perform channel coeffi- cients estimation relying on known training sequences. However in wireless systems, performance and mobility can be further enhanced either by operating semi-blind channel estimation refinement or variation tracking between reference symbols. In this paper, we propose an EM-based channel tracking method using a simple order 1 AR modelling of the channel variations. The proposed approach is applicable to both single carrier and OFDM systems. Simulation results presented in the context of 5 GHz WLANs show that this new algorithm allows to reach the performance of a receiver having a perfect knowledge of the channel coefficients even in the mobile environment (3 m/s).