User Selection Algorithms for Simultaneous Unicast and Multicast Services

This paper presents a transmitting scheme and corresponding user selection algorithms for simultaneous unicast and multicast services. On the subcarriers assigned to multicast services, BS transmits the superposition of unicast and multicast signals. Block diagonalization (BD) and power control are applied to unicast signal, to make sure interference from unicast not reduce the rate of multicast signal. We propose the optimal and a suboptimal user selection scheme to make the unicast rate as much as possible. Theoretical analysis and simulation results show that, the performance of the suboptimal scheme is close to that of the optimal approach, while the complexity is effectively decreased. Besides that, both the optimal and suboptimal schemes can get better unicast rate than random selection while the multicast rate is the same as the one before superposition.