Max‐min energy‐efficient subchannel assignment and power allocation in interference‐limited OFDMA heterogeneous networks with QoS guarantee

Abstract

This paper investigates fairness among all small‐cell users (SCUs) in terms of energy efficiency for the uplink transmission of interference‐limited orthogonal frequency‐division multiple access–based heterogeneous networks. Each SCU is treated by a minimum data rate. In addition, a maximum tolerable interference for the macro base station has been considered. The resulting resource allocation problem is formulated as a nonconvex mixed‐integer nonlinear problem. In order to solve the mixed‐integer nonlinear problem, the subchannel assignment and the power allocation are applied separately; an efficient subchannel assignment algorithm has been proposed where the co‐tier and cross‐tier interference in the most general form has been taken into account. Then, to solve the power allocation subproblem, an iterative algorithm has been proposed by applying generalized fractional programming and sequential convex programming when a specified subchannel assignment is in hand. Performance of the proposed model has been evaluated, and simulation results indicate a fair resource allocation with a very high energy efficiency among SCUs comparing the state‐of‐the‐art solutions.

Joint resource block and power allocation in heterogeneous cellular networks with different backhaul capacity limitations

“…There have been several existing works on resource allocation and interference mitigation in HCNs to optimize the throughput of small cells 2‐7 and energy efficiency 8‐12 . In orthogonal frequency division multiple access (OFDMA) HCNs, the authors in Reference 2 proposed a joint subchannel and power allocation scheme to maximize the sum rate of all users in small cells with consideration of different services requirements and the cross‐tier interference limitation.…”

“…An adaptive graph coloring approach for fractional frequency reuse was designed in Reference 11 with the objective of minimizing the number of required RBs to meet the minimum rate requirement of users, in order to investigate fairness among all small‐cell users in terms of energy efficiency in heterogeneous networks. Besides, the authors in Reference 12 investigated the joint subchannel and power allocation in OFDMA HCNs to achieve the max‐min energy efficiency fairness among all small cell users.…”