Optimal Power Control for D2D Communications under Rician Fading: A Risk Theoretical Approach

Device-to-device communication is a technology that allows users in close proximity to establish a direct communication link instead of passing through the base station. Because direct communications are likely to have a strong line- of- sight component in the received signal, it is reasonable to model the direct channel with Rician fading. In this paper, we propose a power- control scheme for device-to-device communications on a shared channel. Our allocation minimizes the total power consumption while limiting the link outage probability due to Rician fast fading. By leveraging the concept of conditional-value-at-risk from the field of finance, we obtain a linear programming formulation which can be efficiently solved. Through simulation results we show the benefit of the proposed power allocation compared to a deterministic power control that does not account for the random channel variations. Moreover, we provide insights into how the network topology and the parameter settings affect the performance and feasibility of the power allocation.