Energy Efficient Optimization Algorithm for Distributed Antenna Systems

In order to realize green communication, a transmission optimization algorithm for maximizing the system energy efficiency was studied for distributed antenna systems subject to the transmit power constraint of per remote radio head, the fronthaul capacity constraint of per fronthaul link, and the user specific rate constraint. It is difficult to obtain the optimal solution of the considered problem, which is a nonconvex problem due to the existing distributed fronthaul capacity constraint and the fractional form of the definition of energy efficiency. In order to address the optimization problem, fractional programming and successive convex approximation methods were used to transform the original problem into a convex problem. And a twolayer iterative optimization algorithm was proposed. The convergence of the proposed algorithm was ensured by theoretical analysis. Simulation results reveal that the proposed algorithm outperforms conventional algorithms, and the energy efficiency of compression before precoding strategy increases as the number of scheduled users of each RRH decreases.