Abstract : In this paper, we propose a novel power allocation algorithmto maximize the spectral efficiency (SE) and energy efficiency(EE) of multiple-input multiple-output (MIMO) broadcastchannels under individual quality of service (QoS) constraints.In several wireless applications, one of the most important factorsfor QoS guarantee is delay outage. To address the impact ofdelay outage occurring in the link layer, effective capacity (EC)that means the maximum constant arrival rate satisfying statisticaldelay-QoS constraint is considered. Using a novel performancemetric, effective-EE, which is defined as EC divided by total powerconsumption, we formulate an EC and effective-EE maximizationproblem with QoS constraints as an adaptive power allocationproblem. By applying Lagrangian method, we solve optimizationproblem and propose an optimal power allocation algorithm. Simulationresults demonstrate that our proposed algorithm can improvethe EC and effective-EE performance.
Index terms : Delay outage, effective capacity, energy efficiency, MIMO broadcast channels, power allocation, quality of service.