Joint channel allocation and power control for D2D communications using stochastic geometry

Device-to-Device (D2D) communication is a viable network technology that can potentially enhance the spectral and energy efficiency of cellular networks. To exploit this benefit in D2D-underlaid cellular networks, the co-channel interference between D2D and cellular users should be properly managed. In this paper, we propose a joint channel allocation (CA) and power control (PC) scheme to mitigate interference in a D2D underlaid cellular system modeled as a random network using stochastic geometry. The novel aspect of the proposed CA scheme is that it enables D2D links to share resources with multiple cellular users as opposed to one as previously considered in the literature. The PC scheme compensates for large-scale path-loss effects by employing distance-dependent path-loss parameters with an estimation error margin. Closed-form expressions for the coverage probability of cellular links, D2D links, and the sum rate of the D2D links are derived in terms of the allocated power, density of the D2D links, and the path-loss exponent. Simulation results demonstrate an enhancement of 10%-40% for the cellular and D2D coverage probabilities, and 35% for spectral efficiency.