NOMA inspired multicasting in cognitive radio networks

• Published in: IET communications 2018-09, Vol.12 (15), p.1845-1853
• Main Authors: Bhattacharjee, Sangeeta, Acharya, Tamaghna, Bhattacharya, Uma
• Format: Article
• Language: English
• Subjects: base station; cognitive radio; cognitive radio networks; cooperative multicasting; diversity reception; ergodic capacity; multicast protocols; multi‐access systems; NOMA inspired multicasting; nonorthogonal multiple access scheme; outage performance; outage probabilities; primary user multicast group; probability; PU licenced spectrum; PU signals; radio networks; radio spectrum management; secondary user MG; spatial diversity; Special Issue: Recent Advances on 5G Communications; spectrum sharing protocol; SU signals; SU‐MG; telecommunication network reliability; transmission phases
• ISSN: 1751-8628; 1751-8636
• DOI: 10.1049/iet-com.2018.5335

This study outlines a non-orthogonal multiple access (NOMA) scheme for cooperative multicasting in a cognitive radio network. The network consists of a common base station (BS), which serves a primary user multicast group (PU-MG) and a secondary user MG (SU-MG). The SU-MG is located in between the BS and the PU-MG. Their proposed spectrum sharing protocol comprises of three transmission phases. The first phase is utilised by the BS for multicasting both PUs' and SUs' signals, using NOMA transmission. In the second phase, to overcome fading impairments, the BS exploits spatial diversity among SUs, by seeking their cooperation to relay PUs' message signal. The BS, as an incentive, leases a time slot in the third phase, exclusively for supporting multicast to SU-MG over PUs' licenced spectrum. Analytical expressions for outage probabilities of both PU-MG and SU-MG are derived and validated using simulations. Furthermore, outage performance of PUs and ergodic capacity of SUs are compared with a prominent recent scheme.