Power Allocation and User-AP Connection in Distributed Massive MIMO Systems

Abstract

Recently, distributed massive multiple-input multiple-output (MIMO) systems have gained a lot of attention, in which many access points (APs) are deployed in a wide area to simultaneously serve users. This letter investigates a combination of two problems in distributed massive MIMO systems: user-AP selection and power allocation. We derive a closed form of the user achievable rate and use it to form a sum spectral efficiency maximization problem with limited power used in each AP, considering user pilot and data power as variables. Moreover, we propose an approximation of the proposed problem and solve it in an iterative manner. Simulation results prove the effectiveness of proposed scheme in aspects of sum rate performance and AP-user connection.