MIMO doubly-iterative receivers: pre- vs. post-cancellation filtering

We describe and analyze two receivers for turbo space-time codes. These are doubly-iterative, and include iterations for turbo decoding as well as for spatial-interference canceling. The first receiver has a minimum-mean-square-error filter preceding the canceler, while in the second one the filter follows the canceler. The latter outperforms the former at the price of a modest complexity increase.