A Review on SDR, Spectrum Sensing, and CR-based IoT in Cognitive Radio Networks

Abstract

The inherent scarcity of frequency spectrum, along with the fixed spectrum allocation adopted policy, has led to a dire shortage of this indispensable resource. Furthermore, with the tremendous growth of wireless applications, this problem is intensified as the unlicensed frequency spectrum becomes overcrowded and unable to meet the requirement of emerging radio devices operating at higher data rates. Additionally, the already assigned spectrum is underutilized. That has prompted researchers to look for a way to address spectrum scarcity and enable efficient use of the available spectrum. In this context, Cognitive Radio (CR) technology has been proposed as a potential means to overcome this issue by introducing opportunistic usage to less congested portions of the licensed spectrum. In addition to outlining the fundamentals of Cognitive Radio, including Dynamic Spectrum Access (DSA) paradigms and CR functions, this paper has a three-fold objective: first, providing an overview of Software Defined Radio (SDR), in which the architecture, benefits, and ongoing challenges of SDR are presented; second, giving an extensive review of spectrum sensing, covering sensing types, narrowband and wideband sensing schemes with their pros and cons, Machine Learningbased sensing, and open issues that need to be further addressed in this field; third, exploring the use of Cognitive Radio in the Internet of Things (IoT) while highlighting the crucial contribution of CR in enabling IoT. This Review is elaborated in an informative fashion to help new researchers entering the area of Cognitive Radio Networks (CRN) to easily get involved.

Hardware-Accelerated Real-Time Spectrum Analyzer With a Broadband Fast Sweep Feature Based on the Cost-Effective SDR Platform

“…Thanks to technological developments, this idea has evolved over time, and the solution has now been commercialised. An interesting review on SDR in function of spectrum sensor can be found in [13].…”

Cooperative Spectrum Sensing with Amplify and Forward Scheme in CRNs

“…Radio technology is required as a cognitive network in order to overcome the problems in the unused spectrums. [35] The research that is being done in this field is still in its early phases, but it is progressing very quickly(M. Awasthi, 2017) [11]. The military, health care, household appliances, real-time monitoring, and vehicle networks are some of the prospective industries that could benefit from CR (Muhammad Hamad Alizai, 2009) [5].…”

Features measurement analysis of pull-in voltage for embedded MEMS

“…For example, RF-MEMS filters and resonators are intended for applications such as duplex filters, RX&TX band filters, global positioning system (GPS) filters, VCOs, reconfigurable antennas and reference oscillators [6]- [8]. The other application field is RF-MEMS switches, which are very interesting for multi-system phones and with IoT [9], [10].…”