A Technique for Cloud Based Clustering and Spatial Resource Reuse and Scheduling of 3D In-Building Small Cells Using CoMP for High Capacity CRAN

In this paper, we propose a technique for cloud coordinated clustering and scheduling of small cells, i.e., femtocells, in CRAN to improve capacity and spectral efficiency in 3D in-building environments. Control-and user-plane of each cell is decoupled. The clustering technique consists of two levels of clustering such that level 1 clustering defines an initial 3D femtocell cluster size. Level 2 clustering defines a cooperating set of femtocells per floor within each level 1 cluster to explore joint transmission coordinated multipoint (CoMP) during off-states of their transmit power. Femtocells are split at the MAC layer, and a mechanism is presented to model the bandwidth and latency fronthaul constraints. We derive the system level aggregate capacity, spectral efficiency, and energy efficiency. We then develop a heuristic algorithm and discuss its scheduler implementation. With numerical and simulation results, we show with an example scenario that the proposed technique can achieve the maximum CoMP capacity gain of 44% per building and 32.15% in overall system level. Finally, we demonstrate that the proposed technique can achieve the performance requirements of 5G cellular systems and point out the significance and further research issues.