Abstract
An exponentially growing number of internet-of-things (IoT) devices is expected to bring wireless networks to their limits due to the resulting bandwidth scarcity problem. To counterbalance bandwidth bottlenecks, novel design configurations for radio-frequency components that bring flexibility and reconfigurability to modern IoT networks wireless networks are required. Moreover, next-generation networks are expected to support incredibly high data rates, massive connectivity, latency, energy, and cost-critical applications. In this direction, operators opened the door to the millimeter wave (mmWave) band. However, mmWave communications come with limitations. Two of the most important limiting factors are the high path loss and the high penetration loss due to blockage. Possible approaches to constrain the impact of these factors while exploiting the underutilized spectrum lie in spectrum sensing/sharing and spatial diversity. Spectrum sensing allows secondary IoT users to detect spectrum holes and utilize the licensed bandwidth without causing interference to primary users. In this work, we introduce the implementation of an energy detector for spectrum sensing by using the fluid antenna system (FAS), which increases spatial diversity and improves the detection probability. Due to the dense employment of multiple antenna ports over a half-wavelength order antenna length, FAS can fit up to hundreds of antenna ports. This work presents a newly derived analytical expression for the average detection probability given FAS receiver over correlated Nakagami-m fading channels. Numerical results demonstrate that FAS considerably enhances the energy detector’s performance.