Cooperative energy trading in CoMP systems powered by smart grids

This paper studies the energy management in the coordinated multi-point (CoMP) systems powered by smart grids, where each base station (BS) with local renewable energy generation is allowed to implement the two-way energy trading with the grid. Due to the unevenly generated renewable energy over distributed BSs and the difference in the prices for buying/selling energy from/to the gird, it is in general beneficial for the cooperative BSs to jointly manage their energy trading with the grid and energy consumption in CoMP based communication for reducing the total energy cost. We consider the downlink transmission in one CoMP cluster by jointly optimizing the BSs´ purchased/sold energy units from/to the grid and their cooperative transmit beamforming, so as to minimize the total energy cost subject to the given quality of service (QoS) constraints for the users. By applying techniques from convex optimization and uplink-downlink duality, we propose an efficient algorithm to solve this problem optimally. Through simulations, we show the performance gain achieved by our proposed joint energy trading and communication cooperation scheme in terms of cost reduction, as compared to a baseline scheme with the separate designs of communication cooperation and energy trading.