Efficient scheduling and power allocation for multiuser decoding receivers in OFDMA networks with minimum rate requirements

Abstract

In recent years, techniques for exploiting interference on the receiver side to improve the performance of future cellular networks have been of interest. Due to the dominance of data in network traffic, user rate demands are becoming crucial for resource allocation of cells in the network.We propose an efficient transmission scheme for the downlink of an OFDMA multicell multiuser system with multiuser decoding (successive interference cancellation (SIC), joint decoding (JD), single decoding (SD)) capable receivers. We define a marginal rate maximization problem taking into account minimum rate demands of users and develop a practical scheduling (subchannel assignment) and power allocation algorithm using Lagrangian dual decomposition and gradient (ellipsoid and projected subgradient) methods. In the subchannel assignment, we propose the ratio of direct-to-cross channel strengths and multiuser rate regions different than the studies in the literature. Through Lagrangian dual decomposition, we derive the optimal power allocation rule using multiuser decoding modes for a given subchannel assignment.We observe that the method proposed here has low computational complexity and can be easily integrated to next generation networks as well as achieving high performance in practical scenarios.