부산대학교 도서관

Device-to-Device (D2D) communication is a promising technique to enhance the energy efficiency (EE) of green communication networks. In this paper, the energy-efficient joint power allocation (PA) and beamforming design algorithm for D2D-enabled distributed multiple-input multiple-output (D-MIMO) system is proposed. The objective is to maximize EE of the cellular user while ensuring the power and beamforming constraints and D2D user's minimum rate requirement. In order to make the non-convex and non-linear optimization problem solved, the original problem is decomposed into two subproblems using the block coordinate descent algorithm. The developed joint algorithm can compute closed-form solutions for users’ PA and beamforming. Compared with the benchmark scheme based on exhaustive search method, the proposed joint algorithm can achieve almost the same EE performance but yield lower complexity. Besides, with the increase of the receive antennas number, the EE will increase. Moreover, the EE performance will become better than that without D2D communication, as expected. Numerical simulations confirm the effectiveness of the joint algorithm in improving EE gain and reducing complexity.