Hybrid Channel Assembling and Power Allocation for Multichannel Spectrum Sharing Wireless Networks

Channel assembling (ChA) is a technique through which a user performs concurrent transmissions through multiple channels to maximize capacity in wireless networks. This paper proposes a hybrid ChA scheme for overlay and underlay secondary user (SU) transmissions in cognitive radio networks (CRNs). The main objective is to determine the optimal channel selection together with the associated power distribution. This aims to maximize SU capacity subject to total power constraint, minimum quality-of-service (QoS) requirement on capacity, collision constraint and transmission power constraint to protect primary user (PU) services. A Lagrangian framework is employed to reformulate the otherwise mixed integer nonlinear programming (MINLP) problem, based on which Lambert-W function with dual decomposition and subgradient iterative search methods are used to determine the optimal solution. In general, the presented simulation results illustrate significant performance improvement in terms of channel capacity, outage probability and collision probability when employing the proposed hybrid ChA scheme for SU transmissions.