Nonlinear joint transceiver design for coordinated multi-cell systems with energy cooperation

This paper studies the nonlinear transceiver design in downlink coordinated multi-cell system where base stations (BSs) are powered by hybrid sources, including conventional grid and renewable energy. Renewable energy is collected by energy harvesting equipment deployed at BS. However, the harvested energy from different BSs varies in space and time, and the system gain will be limited by the least energy of the coordinated BSs. One of the methods to settle this drawback is energy cooperation among BSs. The nonlinear joint transceiver is formulated as an optimization problem to maximize the minimum signal-to-interference noise ratio of streams under the transmit power constraint. The closed-form solutions are derived by the proposed two-step algorithm. The proposed algorithm guarantees the performance balancing among all users and all streams of each user. Simulation results illustrate the performance improvement of the proposed algorithm.