Multi-Flow Transmission in Cellular Systems with Optimal Scheduling and Utility Maximization

We investigate a scheme called multi-flow transmission, which extends selection diversity. Unlike selection diversity, a user receives/transmits distinct information from/to multiple base stations. We allow different amounts of information to be transmitted by/to different base stations. Moreover, we consider MIMO channels. As examples, we consider max-min throughput and proportional fairness for the utility functions. For the MIMO transmissions, we consider capacity-achieving scheme and beamforming. We compare the total utility for both multi-flow transmission and selection diversity. Multi-flow transmission provides an upper bound on the total utility for selection diversity. In our simulations, multi-flow transmission outperforms selection diversity by at most $52\%$ and $30\%$ in terms of the average total utility for max-min throughput and proportional fairness, respectively.