5G Green Communications: Multigroup Multicasting Transmission with SWIPT in C-RAN

The work investigates the downlink multigroup multicast transmission in cloud radio access network (C-RAN), where remote radio heads (RRHs) collaboratively provide information and energy services for single-antenna information and energy receivers. We aim to minimize the total power consumption by designing beamforming vectors, subject to the constraints of data rate, fronthaul capacity and per-RRH transmit power. However, this optimization problem is nonsmooth and nonconvex. To overcome this challenge, a low-complexity algorithm is developed to find the nearly optimal solution, via successive convex approximation and smooth approximation techniques. Through numerical results, the impacts of the thresholds of fronthaul capacity and energy harvested on the optimum power consumption have been investigated.