On the coexistence of D2D and cellular networks: An optimal distributed approach

A promising approach to cope with the increasing data demand in cellular networks is the use of device-to-device (D2D) communications over short distances. It allows to save valuable resources like energy, time and frequency, in particular when the spectrum is shared with the cellular communications. While spectrum sharing can grant a high spectrum reuse, it also requires a proper scheduling, in order to limit the resulting intra-cell interference. In contrast to several recent centralized approaches, in this paper we illustrate how context awareness, derived from the measurement of few local parameters, can be exploited to set up D2D communications in a distributed fashion. The tradeoff between the gain offered by non-orthogonal D2D communications over uplink channels and the impact of the increased interference is derived through a detailed theoretical analysis. As a result of this analysis, we state a theorem to determine the optimal transmission strategy in order to maximize the throughput in a single cell scenario. By comparing our strategy to the state-of-the art in the same network scenario, we show how the adaptivity offered by context awareness can be turned into an improved performance, in terms of sum throughput and fairness.