Resource Allocation for Two-Way Relay-Assisted Hybrid Cognitive Radio Networks

Abstract

In this paper, we focus on the resource allocation (RA) in Orthogonal Frequency Division Multiplexing Access (OFDMA) Two-Way Relay-Assisted (TWR) Cognitive Radio Network (CRN). The spectrum availability in hybrid spectrum sharing was examined based on a sensing-based spectrum sharing. Aggregate Weighted Ergodic Throughput (AWET) of the secondary network was considered as the main objective of the RA. In addition to subcarrier assignment policy, the system design parameters are the transmission power of Secondary Users (SUs), Base Station (BS) and relay nodes, sensing parameters i.e. the sensing time and energy detection threshold. The main contributions of this paper is the proposed novel sensing based RA algorithm and its near optimal solution adopting dual technique coupled with block coordinate descent algorithm for OFDMA TWR-assisted CRNs. Simulation results corroborated the theoretical findings and confirmed the superiority of the hybrid spectrum sharing against overlay and underlay spectrum sharing.