Cloud-CFFR: Coordinated Fractional Frequency Reuse in Cloud Radio Access Network (C-RAN)

Abstract

Fractional Frequency Reuse (FFR) and Coordinated Multi Point (CoMP) processing are two of the conventional methods to mitigate the Inter-Cell Interference (ICI) and to improve the average Signal-to-Interference-plus-Noise Ratio (SINR). However, FFR is associated with low system spectral efficiency and CoMP does not take any action to mitigate the inter-cluster interference. In the context of Cloud Radio Access Network (C-RAN) -- a new centralized paradigm for broadband wireless access that addresses efficiently the fluctuation in capacity demand through real-time Virtual Base Station (VBS) cooperation in the Cloud -- in this paper an innovative uplink solution, called Cloud-CFFR, is proposed to address the aforementioned problems. With respect to both FFR and CoMP, Cloud-CFFR decreases the complexity, delay, and ICI while increasing the system spectral efficiency. Since the system performance in cell-edge regions relies on the cooperation of different VBSs, there is no service interruption in handling handovers, moreover, in order to address the unanticipated change in capacity demand, Cloud-CFFR dynamically changes the sub-band boundaries based on the number of active users in the clusters. Simulation results confirm the validity of our analysis and show the benefits of this novel uplink solution.