Energy Efficient Power Control and Relaying for C-RAN Uplink With Wireless Fronthaul

This work proposes an energy-efficient design of transmit power control and relaying strategies for the uplink of a cloud radio access network (C-RAN) with wireless fronthaul link. In the system, a set of single-antenna user equipments (UEs) send independent messages to a multi-antenna baseband processing unit (BBU) through a set of parallel multi-antenna remote radio heads (RRHs). The radio access link from the UEs to the RRHs is assumed to be orthogonal to the fronthaul link from the RRHs to the BBU. Since the overall performance of the system may be limited by the battery constraints of the UEs, this work tackles the problem of maximizing the worst energy efficiency of the UEs subject to the transmit power constraints at the UEs and the RRHs. Numerical results are provided to validate the advantages of the proposed energy-efficient scheme.