Real-Time Partitioned Scheduling In Cloud-Ran With Hard Deadline Constraint

With centralized baseband unit (BBU) pool, CloudRAN (C-RAN) has powerful computation capability to support joint-process signals for multiple remote radio heads (RRHs) simultaneously. It raises a challenge to fully utilize the computation resources and meet the hard deadline constraint posed by multimedia traffics. To overcome this challenge, a real-time partitioned scheduling algorithm called Wi-EDF has been proposed in this work. In order to improve the efficiency of Wi-EDF, a cross layer scheduling framework is presented. Based on that, Wi-EDF is carrying out in a two-level scheduling manner. In the first level, a beamforming based scheduling problem shows up, which aims to minimize the system power consumption with the constraint of fronthual capacity. The problem can be iteratively solved by the equivalent second order cone program (SOCP) problems. In the second level, a preemptive earliest deadline first (EDF) based scheduling algorithm with admission control has been designed. The processing time deduced by the baseband signaling has been taken into account in this level. The simulation results show that Wi-EDF has lower power consumption, higher CPU utilization and higher overall throughput comparing with LTE-A.