Blind channel estimation for single carrier and multicarrier systems

Block transmission has recently been considered as an alternative to the conventional continuous transmission technique. In particular, block transmission with zero padding (ZP) was noticed for its ability to recover transmitted symbols regardless of the channel zero locations. In this paper, we present blind channel estimators for block transmission employing zero padding for both single carrier (SC) and multicarrier (MC) systems in the presence of narrowband interference. The proposed estimators take the same form, which gives flexibility for application to either SC or MC with minor changes. Our approach uses a generalized multichannel minimum variance principle to design an equalizing filterbank. Channel estimate is then obtained by deriving an asymptotically tight lower bound of the filterbank output power. Numerical examples show that the proposed schemes exhibit low sensitivity to unknown narrowband interference and compare favorably with a subspace blind channel estimator.