A soft-decision approach for BLAST systems with less receive than transmit antennae

In this paper, a soft-decision based detection technique is developed for BLAST MIMO systems with less receive (Rx) antennae than transmit (Tx) antennae. The existing ing and cancellation algorithm (NC) is unable to work for such systems theoretically. Avoiding any zero-forcing mechanism, the proposed approach works for rank-deficient channels via soft-decision based interference cancellation. Moreover, it outperforms NC in BLAST systems with more Rx than Tx antennae. The computational cost of the proposed approach is only on the 3rd order of the number of symbols to be recovered and linear in the signal constellation size, which is lower than the complexity of NC. This paper establishes the soft-decision approach as an attractive candidate to achieve detection performance better than that of NC. Simulation comparisons of the soft-decision approach with the NC algorithm are presented.