Although network assisted device-to-device (D2D) communications is known to improve the spectral and energy efficiency of proximal communications, its performance is less understood when employed to extend the coverage of cellular networks.
In this paper, we study the performance of D2D based range extension in terms of sum rate and power efficiency when a relaying user equipment (UE) helps to improve the coverage for cell-edge UEs. In our design, the relaying UE has own traffic to transmit and receive to/from the cellular base station (BS) and can operate either in amplify-and-forward (AF) or decode-and-forward (DF) modes and can make use of either digital or analogue (PHY layer) network coding.
In this rather general setting, we propose mode selection, resource allocation and power control schemes and study their performance by means of system simulations. We find that the performance of the DF scheme with network coding is superior both to the traditional cellularand the AF based relaying schemes, including AF with two-slot or three-slot PHY layer network coding.
Authors: Abrardo, Andrea | Fodor, Gabor | Tola, Besmir