Multiuser spatial scheduling in the downlink of wireless systems

Optimizing a communication of a Q-antenna access point (AP) with K single antenna terminals is not straightforward. Since a global optimization might not be solvable in real time, the AP has several alternatives involving both the physical layer, e.g. beam-forming and power/bit allocation, and the DLC, such as scheduling. The purpose of this paper is twofold. First, for K≤Q we compare traditional bit allocation strategies with a novel modified approach, especially in terms of fairness. Second, we focus on the combinatorial problem that arises when K>Q, and propose several alternatives for the scheduling of the users into groups, which is done together with the bit allocation. Simulations show that better performance is obtained at the expense of complexity.