The Ergodic Rate Density of MIMO Ad-hoc Networks

We analyze the scaling laws of the Ergodic Rate Density (ERD) in ALOHA Wireless Ad-hoc Networks (WANETs) that utilize Multiple-In-Multiple-Out (MIMO) techniques. We present a novel lower bound that support spatial-multiplexing, interference-cancellation and beamforming. The bound is used to present expressions of the optimum system parameters as function of the number of antennas and the path-loss factor. When the density of active users can be tuned to maximize the performance, we show that the ERD scales linearly with the number of antennas and that single stream transmission optimizes the network performance. When the active users density is limited and it´s below 70% of the optimal density, spatial multiplexing was shown to have better performance than single stream transmission. Simulation results show the practically of the novel bound and the accuracy of the estimated parameters.