A network perspective of MIMO antenna techniques with multiuser scheduling

Summary form only given. Multiple-input multiple-output (MIMO) antenna techniques can achieve huge capacity gains without requiring extra bandwidth. The primary challenges to apply the MIMO techniques lines in the implementation complexity and the possible side effect of reliability performance degradation. Many research efforts, especially the physical layer techniques, have been reported in the literature to resolve these issues. Differently, this talk provides a network perspective to implement the MIMO techniques in wireless scheduling systems. First, we propose using the scheduling techniques to replenish the diversity-deficient spatial multiplexing MIMO system. To this end, we develop a novel strongest-weakest-normalized-subchannel-first (SWNSF) scheduling algorithm to enhance the degraded reliability performance of the MIMO system with limited feedback information. Our analysis indicates that the SWNSF scheduling can significantly increase the coverage of the multiuser MIMO system while improving system capacity. Secondly, we investigate the effect of multi-user scheduling techniques on the simple zero-forcing receiver based spatial multiplexing MIMO system. Somewhat surprisingly, we find that the zero-forcing receiver can be asymptotically optimal in the multiuser scheduling system as the number of users increase. In summary, by full exploitation of the existing rich network resource - the inherent multiuser diversity, we show that the coverage and complexity issues of the MIMO system can be resolved with a negligible cost. More important than the results presented and also the ultimate goal of this talk, is the hope that the network perspective methodology can provide another innovative view and flexible design paradigm for MIMO wireless systems.