Distributed Resource Allocation for Cognitive Radio Networks: Sub-Carrier Power and Bandwidth Sizing

This paper addresses distributed sub-carrier bandwidth sizing and power allocation for the Secondary Users (SUs) in a Cognitive Radio (CR) network. The system entails an Orthogonal Frequency Division Multiplexing (OFDM)-based multi-user environment which deploys overlay spectrum sharing by the Primary Users (PUs) and SUs, and Frequency Division Multiple Access (FDMA) for the SUs. The objective of the formulated problem is maximizing each SUs throughput within a node power budget, interference threshold on the PU band, consideration of the interference caused to the neighboring SUs, as well as the coherence bandwidth of each SU. Motivated by the nonconvex structure of the problem and the need to execute the resource allocation in a distributed manner, we propose a sub-optimum algorithm to achieve the objective within the specified constraints. Simulation results highlight the contribution of the proposed distributed resource allocation algorithm and demonstrate its effectiveness.