An efficient radio-frequency spectrum utilization technique for cognitive radio networks

Cognitive radio (CR) is a rising technology that unlocks the doors for radio spectrum scarcity problem, which is of great concern nowadays among the researchers at various levels. CR enables to unlicensed users or secondary users (SUs) to access the primary channels when licenced users or primary users (PUs) are not using these channels. Two fundamental access methods namely overlay and underlay are very popular in utilizing the free available channels or the white spaces. Various hybrid access methods have been proposed and recommended by many researchers to further enhance the radio spectrum utilization. Of course hybrid access methods are the better ways to deal this spectrum scarcity problem, but a comprehensive and directed effort is required to optimize the modality of these methods. This work proposes a Markov chain based hybrid access method named as Hybrid Spectrum Utilization Technique (HSUT), which tries to maximize the radio spectrum utilization by enhancing the PU's detection probability. This work also analyzes the performance of the HSUT and results obtained through OMNeT++ simulator are very encouraging. At last, this work also compares the performance of the HSUT with the overlay, underlay, Hybrid-P1 (Dhurandher et al., 2021), and the Hybrid-P2 (Dhurandher et al., 2021) access methods.