Modeling and Analysis of Spatial Distributions of Users in Massive MIMO Systems

This paper investigates the impact of changes in the spatial distribution of users on the energy efficiency (EE) of massive multiple-input multiple-output (MMIMO) systems. Specifically, expressions for average transmit power are developed in Poisson Point Process (PPP) of users with power control cancelling the effects of deterministic signal attenuation with distance. The user positions given by their coordinates in 2D are modeled through different bivariate random variables (RVs) which in turn result in different univariate RVs representing users equipment (UE) distances from the base station (BS). Assuming perfect power control in the system and interpreting the average transmit power as fractional moments of a distance between the UE and the BS, the average power is evaluated for Gaussian and homogenous distributions of users in 2D. Analytical results are presented to demonstrate the impact on EE due to changes in the spatial distribution of users and the path loss exponent.