Joint Scheduling and Power Allocation in OFDMA Network with Decode-and-Forward Relaying

Abstract

This paper investigates the resource allocation of Orthogonal Frequency Division Multiplexing Access (OFDMA) cellular network with DF relaying in the downlink. A joint scheme of relay selection, subcarrier assignment and power allocation is proposed to maximize the system sum rate subject to individual power constraints and heterogeneous users' rate requirements. Since the original problem is a mixed integer programming (MIP), we transform it to a standard convex optimization by continuous relaxation and solve it via iterative water-filling (IWF) and subgradient methods in the dual domain. Beside the joint scheme, the upper bound is studied through an exhaustive bisection search. Simulations results show that the proposed scheme outperforms the traditional methods in terms of both system throughput and users' satisfactions.