Energy Efficient Subchannel and Power Allocation for Software-defined Heterogeneous VLC and RF Networks

Visible light communication (VLC) is considered as a promising candidate to improve the performance of indoor communication as the complement of wireless radio frequency (RF) communications due to the scarcity of RF resources. Combining the VLC with software-defined small-cell networks will substantially improve the user data rates in indoor heterogeneous networks. In this paper, we introduce the software-defined philosophy into orthogonal frequency-division multiple access-based heterogeneous software-defined and twinned VLC and RF small-cell networks. The pivotal issues of energy efficient (EE) subchannel and power allocation are investigated in the context of software-defined VLC and RF small-cell networks. We formulate the EE resource allocation problem as a non-convex optimization problem, and then, transform it into a convex one using Dinkelbach's method. In addition, distributed subchannel and power allocation algorithms for both VLC and RF are proposed for solving the problem based on the powerful alternative direction method of multipliers. Simulation results verify the effectiveness of resource allocation algorithms conceived for the heterogeneous software-defined twinned VLC and RF small-cell networks in terms of its good convergence and overall performance.