Energy-efficient coverage scheme for relay-assisted D2D network

In this paper, we investigate the energy-efficient coverage problem in relay-assisted D2D network, where the access point and the relays have unknown positions and variable coverage radii. The energy-efficient coverage problem is formulated using the minimum function and the concept of virtual relay point, which is involved for distinguishing relay devices with general devices. The formulated problem is hard to solve since the minimum function is nonconvex. To address this difficult, we transform the primal problem into a standard convex problem by approximating the minimum function with linear weighted sum. Then an iteration-based energy-efficient coverage scheme is proposed to solve the approximation problem, where the initialization and update of weighted values are specifically described. Finally, the simulations are conducted and the results show the performance of our proposed algorithms.