Energy-Efficient Virtual Resource Allocation in OFDMA Systems

Optimization of resource allocation is fundamental to implement orthogonal frequency division multiple access (OFDMA), which energy efficiency (EE) is very much desired. Wireless network virtualization recently emerges to flexibly enable high data rate services, but optimal cross-layer design with OFDMA remains open. While energy efficiency (EE) is a critical issue for OFDMA systems, the appropriate energy efficient design to enable emerging virtualization in wireless OFDMA networks remains open. In this paper, we focus on energy efficient subcarrier and power allocation with wireless network virtualization. To minimize power consumption and to maximize data rate, such virtual resource allocation can be modeled as a non-convex optimization of EE. Exploiting the non-convex fractional programming, we reformulate into a subtractive form as the equivalent optimization.We therefore obtain the iterative algorithm to achieve the optimality. In particular, subcarrier allocation, power allocation, and operator selection in each iteration can be derived by the Lagrange dual decomposition method. Simulations verify that the algorithms can significantly enhance EE in wireless network virtualization architecture.