Downlink resource allocation under channel uncertainties for device-to-device communication

Abstract

For the downlink device-to-device (D2D) communication underlaying cellular networks, we study the resource allocation policy which jointly optimizes the resource block (RB) assignment and the powers of D2D users and cellular users. Aiming to improve the sum-rate of D2D subsystem and ensure the quality of service (QoS) of the cellular networks, a nominal optimization problem is formulated. Furthermore, considering the uncertainty in channel state information (CSI), a worst-case robust optimization problem with ellipsoid uncertainty set is investigated. After transforming the non-convex problem into a convex subproblem, we obtain the closed-form solution of the subproblem by using Lagrangian dual method and Karush-Kuhn-Tucker (KKT) conditions. And the optimal solution of the original problem is obtained by one dimensional search algorithm. The simulation results verify the advantages of the proposed resource allocation policy and illustrate the effect of the robustness in D2D communication system.