  This paper considers the power-efficient resource allocation problem in a
cloud radio access network (C-RAN). The C-RAN architecture consists of a set of
base-band units (BBUs) which are connected to a set of radio remote heads
(RRHs) equipped with massive multiple input multiple output (MIMO), via
fronthaul links with limited capacity. We formulate the power-efficient
optimization problem in C-RANs as a joint resource allocation problem in order
to jointly allocate the RRH and transmit power to each user, and fronthaul
links and BBUs assign to active RRHs while satisfying the minimum required rate
of each user. To solve this non-convex optimization problem we suggest
iterative algorithm with two-step based on the complementary geometric
programming (CGP) and the successive convex approximation (SCA). The simulation
results indicate that our proposed scheme can significantly reduce the total
transmission power by switching off the under-utilized RRHs.
