Cooperative Sensing with Heterogeneous Spectrum Availability in Cognitive Radio

Abstract

In cognitive radio, the throughput efficiency of the secondary user (SU) is determined by spectrum sensing performance and the secondary user's available power to send data. Because the secondary user expends energy for spectrum detection and to maintain cooperation among numerous SUs, transmission power can be reduced. To compensate for this energy, cognitive radio has devised an energy harvesting technology in which the SU may harvest energy from the primary (PU) signal and use it to broadcast data and extend the lifetime. In a typical Energy Harvesting Cognitive Radio Network (EHCRN), SU can perform sensing and harvesting in different slots, reducing the secondary user's transmission time and lowering throughput. In a cooperative wireless network with energy detecting spectrum sensing, the RF energy harvesting approach is researched, and various optimization studies are investigated in this work. First, an energy harvesting is considered with the power splitting technique, Power Splitting Energy Harvesting Cognitive Radio Network (PSEHCRN) to measure the residual energy of SU that can be utilize to improve the transmission efficiency of SU and obtained expressions for throughput and lifetime. Further an energy harvesting with adaptive time switching mode of operation namely Adaptive Time Switching Energy Harvesting CRN (ATSEHCRN) has proposed and analyses the performance in terms of harvested energy, transmission power, throughput and lifetime of SU. This research also offers the Optimum Energy Harvesting Cognitive Radio Network (OTEHCRN)., an optimum energy harvesting technique that can perform spectrum sensing and energy harvesting simultaneously, with the entire incoming radio frequency (RF) power being utilised for energy harvesting. Reduced energy consumption paired with higher energy harvesting allows more energy to be accessible for transmission, resulting in increased SU throughput and longevity. Harvested energy, transmission power, throughput and lifetime are analysed with half duplex and full duplex mode of energy harvesting and compared with the different energy harvesting schemes. The cognitive radio performance of all studies has been verified with MATLAB simulation results.