Capacity Scaling Laws in Interference-Limited Multiple-Antenna AF Relay Networks With User Scheduling

The ergodic capacity of multiuser multiple-antenna amplify and forward relay networks with co-channel interference is investigated. Notwithstanding the system complexity, the proposed capacity analysis framework was made possible owing to the newly found complementary moment generating function transform. First, the exact expression for the ergodic capacity, under interference-aware opportunistic scheduling and Rayleigh fading, is derived for finite antenna and user counts. In addition, using extreme value theory, closed-form expressions for the asymptotic ergodic rates are derived for an unlimited number of users or/and antennas at the source. The large-scale analysis embodies, through new insightful formulas, common popular observations so far disclosed intuitively or empirically. Capitalizing on these novel scaling laws, we have been able to derive new closed-form expressions for capacity losses due to intercell interference at the relay and all users. Simulation results suggest a rather fast convergence of the capacity gains to the new asymptotic limits, thereby demonstrating the practical importance of our novel scaling results.