Utility-Based Resource Allocation with Spatial Multiplexing for Real Time Services in Multi-User OFDM Systems

In order to expand its market share and decrease churn, cellular network operators want to achieve the maximum possible number of satisfied clients. In this paper, we propose to solve the problem of user satisfaction maximization using an utility- based dynamic resource assignment algorithm that uses a sigmoidal utility function combined with either Orthogonal Random Beamforming (ORB) or Fixed Switching Beamforming (FSB). System-level evaluations of the downlink of an Orthogonal Frequency Division Multiple Access (OFDMA) system with real-time services demonstrate that there is an optimal number of spatial beams to be used by ORB and FSB, that FSB outperforms ORB with lower complexity, and also that the proposed joint resource assignment and beamforming outperforms other classical techniques found in the literature.