Power Control for D2D Underlaid Cellular Networks: Modeling, Algorithms and Analysis

This paper considers a device-to-device (D2D) underlaid cellular network where an uplink cellular user communicates with the base station while multiple direct D2D links share the uplink spectrum. This paper proposes a random network model based on stochastic geometry and develops centralized and distributed power control algorithms. The goal of the proposed power control algorithms is two-fold: ensure the cellular users have sufficient coverage probability by limiting the interference created by underlaid D2D users, while also attempting to support as many D2D links as possible. For the distributed power control method, expressions for the coverage probabilities of cellular and D2D links are derived and a lower bound on the sum rate of the D2D links is provided. The analysis reveals the impact of key system parameters on the network performance. For example, the bottleneck of D2D underlaid cellular networks is the cross-tier interference between D2D links and the cellular user, not the D2D intra-tier interference. Numerical results show the gains of the proposed power control algorithms and accuracy of the analysis.