Power optimization for D2D communication based on rate requirement in relay-assisted networks

In this paper, a power optimization strategy is studied in underlay Device-to-Device (D2D) communication coexisted heterogeneous wireless networks with relay-assisted. In order to reduce the power consumption of cellular users (CUs), especially those far away from the base station (BS), we introduce the relay node (RN) to help transport its data to BS with less power consumption. By taking the advantage of short-distance transmission, one D2D pair is available to reuse multiple spectrum resources of CUs with the guarantee of the minimum achievable rate threshold of D2D link and cellular link so that the corresponding quality of service (QoS) could be satisfied while improving the spectrum utilization. In our paper, an optimal algorithm is proposed to conduct the power optimization problem with relay-assisted, which is formulated as a mixed integer programming (MIP) problem. And a suboptimal algorithm is also provided without relay-assisted. The simulation results show that our optimal algorithm makes a great deal of power saving with relay-assisted.