Evaluation of Functional Splits in terms of Optimal Number of Users Served in 5G Downlink

5G is expected to provide reliable and high-speed broadband services for connecting, monitoring and controlling everything everywhere wirelessly. Millimeter Wave spectrum, massive Multiple Input Multiple Output (mMIMO), and Cloud Radio Access Network (C-RAN), are the key technologies which are expected to make 5G a reality. When massive MIMO is implemented in the context of C-RAN, the fronthaul capacity and the choice of functional split will limit the number of antennas that can be used. This effects the maximum achievable sum rate. In this paper, we estimate the maximum number of antennas that can be used at each functional split. Further, the optimal number of users that can be served at each functional split, with Zero-Forcing (ZF) & Maximum Ratio Transmission (MRT) beamforming techniques is also investigated. It is observed that, split option 1 supports the maximum number of antennas, and serves the maximum number of users.