Joint user scheduling and power allocation with quality of service guarantees in downlink distributed antennas system

In this study, the authors study the downlink joint user scheduling and power allocation in a single-cell distributed antennas system. Considering that all users are delay sensitive and without any assumption on the feasibility of the system, they formulate an optimisation problem to minimise the total power consumption while maximising the number of satisfied users. Given a user scheduling result, a deflation-based joint user removal and power allocation algorithm and a conservative power allocation algorithm are proposed. Owing to the complexity in full enumeration of all user scheduling results, they further propose a joint heuristic user scheduling and power allocation algorithm, in which a priority parameter is defined to determine the user scheduling order and the conservative power allocation algorithm is applied to execute the power allocation. The user with the worst quality of experience is iteratively removed away from the active user set until all the remaining users are guaranteed with their quality of service requirements. Simulation results show that the authors proposed heuristic algorithm obtains a near optimal system performance in both user outage ratio and total power consumption.