Practical implementation of real-time cognitive radio energy detector using frequency reconfigurable filtenna

摘要

In this paper, a new design of cognitive radio (CR) system based on a reconfigurable filtenna, RF power detector, and Raspberry pi is proposed. It provides a fast and cheap solution to efficiently detect the spectrum holes over the frequency range from 2.37 to 3.69 GHz. The frequency scanning is performed by using a compact narrow bandwidth filtenna. The electrical frequency reconfiguration is achieved by incorporating a varactor diode into the filtenna structure. Under the control of Raspberry pi, the frequency tuning is done by varying the voltage across the varactor from 0 to 30 Volts. Followed by the filtenna, an RF power detector circuit is utilized to monitor the primary user (PU) existence. Different scenarios of measurements are carried out to verify the reliability and successfulness of the proposed prototype.