Spatial vs. multi-user diversity trade-offs for cross-layer scheduling in limited feedback systems

In this paper, we explore spatial vs. multi-user diversity trade-offs in a cellular system with or without bandwidth restrictions in the feedback channel. More precisely, we are interested in assessing the impact of both antenna selection and space–time coding strategies in such a multi-user system. The centralized scheduler makes an extensive use of physical layer measures and, hence, this constitutes a cross-layer design. Performance assessment is conducted both analytically and by means of computer simulations, in terms of pdf and CDF distributions, average system capacity and throughput. Closed-form expressions are derived for the SNR densities associated to the different transmission configurations along with an approximate expression for system throughput.