Soft-iterative estimation of structured channels: performance analysis and comparison

In this paper we propose a new soft-iterative method for the estimation of block-fading channels based on multi-block (MB) processing. The MB estimator exploits the invariance of the subspace spanned by the multipath components of the channel and it estimates the channel subspace by sample averaging over a frame of blocks. Here the MB method is extended to incorporate soft information, which is available in iterative equalizers. A performance evaluation and comparison with other soft methods in the literature is carried out showing the benefits of the proposed approach on the turbo equalizer convergence.