Energy efficient joint subchannel selection and resource allocation for heterogeneous CRNs

Cognitive radio networks (CRNs) are expected to improve spectrum utilization significantly by allowing secondary users (SUs) to opportunistically access the licensed spectrum of primary users (PUs). In a CRN scenario consisting of multiple heterogeneously integrated CRNs, the SUs with multiple interfaces may have to conduct spectrum handoff to target subchannels. Jointly considering the interruption delay and the transmission performance of the handoff SUs on target subchannels, the subchannel selection and resource allocation optimization problem which maximizes the energy efficiency of all the interrupted SUs under the quality of service (QoS) constraints is formulated and solved through applying iterative algorithm and Lagrange dual method. Numerical results demonstrate the efficiency of the proposed scheme.