Energy Efficiency Optimization of Multi-user Distributed Antenna Systems with SWIPT Technique

For the multi-user downlink distributed antenna system with the technique of simultaneously wireless information and power transfer, a system model is established and the energy efficiency problem based on this model is formulated. The original problem is decomposed into several sub optimization problems as it is a nonlinear fractional programming problem and also a non-convex problem that is difficult to solve. Then, an algorithm of jointly optimizing energy distribution and power split ratio, named as the iterative Lagrangian double-layer iterative algorithm, has been proposed for solutions, combining the considerations of user transmission rate and energy harvesting rate of UE. Finally, the simulation results are presented to validate mathematical analysis.