Device-to-Device Communications Underlaying Cellular Networks

TLDR

Device‑to‑device communication enables direct links between nearby users, improving spectral efficiency but potentially causing interference, with performance influenced by user locations, cell size, active user counts, and D2D power limits. The study aims to maximize overall network throughput while ensuring quality‑of‑service for both D2D users and conventional cellular users. A three‑step scheme is proposed, beginning with admission control and power allocation for admissible D2D pairs and their cellular partners, followed by a maximum‑weight bipartite matching to select suitable CU partners that maximize throughput. Simulation results demonstrate that the scheme markedly increases D2D access rates and overall network throughput.

Abstract

In cellular networks, proximity users may communicate directly without going through the base station, which is called Device-to-device (D2D) communications and it can improve spectral efficiency. However, D2D communications may generate interference to the existing cellular networks if not designed properly. In this paper, we study a resource allocation problem to maximize the overall network throughput while guaranteeing the quality-of-service (QoS) requirements for both D2D users and regular cellular users (CUs). A three-step scheme is proposed. It first performs admission control and then allocates powers for each admissible D2D pair and its potential CU partners. Next, a maximum weight bipartite matching based scheme is developed to select a suitable CU partner for each admissible D2D pair to maximize the overall network throughput. Numerical results show that the proposed scheme can significantly improve the performance of the hybrid system in terms of D2D access rate and the overall network throughput. The performance of D2D communications depends on D2D user locations, cell radius, the numbers of active CUs and D2D pairs, and the maximum power constraint for the D2D pairs.