Comparing decoding algorithms for multi-layer space-time block codes

In this paper we consider a multiple input multiple output multi-group space-time coding system that is a combination of V-BLAST and space-time block codes. Decoding order is an important issue for serial group interference cancellation (SGIC) algorithm. Different ordering schemes for SGIC are compared. While layers in SGIC suffer from unequal receive diversity, parallel group interference cancellation (PGIC) has the potential to achieve full receive diversity for all the layers. Performance of both the algorithms are analyzed and compared Finally we show that the optimal performance of layered block codes could be achieved by sphere decoding (SD) which approaches the maximum likelihood detection performance with lower complexity. Keywords: Multi-layer system, space-time block codes, sphere decoding, ordering scheme, interference cancellation.