Optimal joint transmission scheduling for green energy powered coordinated multi-point transmission system

Due to advantages in spectral efficiency and energy efficiency of its air-interface, the coordinated multi-point (CoMP) transmission has been adopted in 4G and beyond mobile communication systems, such as LTE-A, which enables the transmission cooperation among multiple remote radio units (RRUs). As the main component of a RRU, the power amplifier (PA) is always blamed for its low power efficiency, which is difficult to be further improved by today´s hardware technology. To eliminate the on-grid power consumption caused by the low PA efficiency and the corresponding CO₂ emission, we propose a new CoMP transmission framework, in which all RRUs and associated PAs are powered by the solar power. Then, based on the proposed framework, we derive the optimal coordinated transmission scheduling algorithm for maximizing the throughput with considerations of fast fading channel, limited pre-knowledge about channel state information (CSI), random energy arrival and finite energy storage. Theoretical analyses of the proposed algorithm are given, and numerical results show that our algorithm can achieve a close performance to the optimal transmission scheduling algorithm with a priori knowledge about CSI.