Download Cognitive Radio and Dynamic Spectrum Access

Cognitive Radio and Dynamic Spectrum Access
Swati Dwivedi and Alkesh Agrawal
Faculty of Electronics and Communication Engineering Institute of Technology
Shri Ramswaroop Memorial University Lucknow, India
Emails: [email protected], [email protected]
Abstract:
The mobile sector continues to see dramatic growth around the world. Usage of cell phones,
smartphones, and tablets is increasing at a rapid pace. With the growing popularity and ease of
use of mobile devices such as iPhone, Android phones, tablets, and other portable devices, new
mobile applications are coming online that increase access and capability, particularly in areas
such as education, health care, transportation, and commerce. But the tremendous increase in
wireless utilization is coming up against the utilization of radio spectrum availability. Cognitive
networks are motivated by the lack of spectrum under the current spectrum management policies.
Most of the frequency bands useful to wireless communication have already been licensed to the
primary users. Recent measurements have shown that for as much as 90% of the time, large
portions of the licensed bands remain unused. As licensed bands were difficult to reclaim and release, dynamic and secondary spectrum licensing was considered as an alternative to reduce the
amount of unused spectrum. Cognitive radio (CR) is a cooperative communication technology
for supporting dynamic spectrum access: Cognitive radio (also called smart radio) can,
intelligently detect which communication channels (spectrum) are in use and which are not, and
avoid occupied channels and instantly move into vacant ones by using dynamic spectrum access.
It allows us to make use of the notbeing-used part of spectrum and thus optimizes the use of
available spectrum while minimizing interference to other users by its spectrum sensing method.
Keywords: cognitive radio, dynamic spectrum, spectrum sensing