Improving Performance of Bell Labs Layered Space-Time Systems by Multiframe Space-Time Interleavers

Turbo-BLAST (T-BLAST) is a multiple-input multiple-output (MIMO) wireless communication system. It is based on three main concepts: Bell laboratories layered space-time (BLAST) architecture, random space-time interleaving, and the turbo principle. T-BLAST system has many advantages including high data rate, excellent performance, and low complexity. These advantages make T-BLAST one the most important choices for future wireless communication systems. In this article, the authors study the effect of the space-time interleaver on the performance of T-BLAST system. This interleaver is split into two separated stages, time interleaving followed by space interleaving. They show that, in a quasi-static channel, the enhancement in performance provided by the time interleavers is very small compared to the gain provided by space interleavers. They also propose a new technique to improve the system performance, called multiframe space-time interleaving (MUSTI). Simulation results show an improvement in performance up to 6 dB at BER=10-4 for a (2,2) configuration.