Energy efficiency for coordinated multi-point uplink with dynamic voltage frequency scaling

We consider the uplink of coordinated multipoint (CoMP) communication system, which demonstrates a benefit of spectral efficiency, especially for cell-edge users. However, its energy efficiency remains to be evaluated. With the possible application of cloud computing into Base Station (BS), dynamic voltage frequency scaling (DVFS) of CPU based on workload is a good way to reduce power consumption of BS. Compared to non-coordinated architecture, the coordination obtains higher spectral efficiency at the cost of additional computation complexity, thus additional power consumption. DVFS techniques can adjust CPU very well to adapt workload variation. In this paper, We model signal to interference noise ratio (SINR) and spectral efficiency for CoMP, and map them to assignment of physical resource block (PRB), modulation coding scheme (MCS) and spatial multiplexing layer, which are related to processing capability requirement and power consumption, then we make use of DVFS to optimize power consumption. We run simulation to make a comparison of spectrum efficiency and energy efficiency between two BSs coordination and non-coordination, the average throughput increases about 50%, but the power consumption of BSs increases 200%, finally the ratio of power consumption to average throughput of CoMP increases about 100%.