What is cognitive radio?
Cognitive radio is a special type of smart radio transceiver hardware that automatically detects all available wireless channels in a spectrum and allows changes to their reception or transmission parameters, allowing the simultaneous transmission of multiple additional wireless communications in a given spectrum. This process is known as dynamic spectrum management.
The main purpose of Cognitive Radio is to discover and share unused spectrum with other systems without creating harmful interference. This includes spectrum management or finding the best spectrum available to meet user communication needs.
Cognitive radio was first proposed in a 1998 seminar by Joseph Mitola III at the Royal Institute of Technology in Stockholm, Sweden. A year later, this new approach to wireless communication was published in an article by Mitola and Gerald Maguire Jr. Initially, it was intended as a software-defined radio extension - full cognitive radio - in which all observable wireless node parameters are taken into account.
That was Mitola's original idea, but most modern research on this technology has focused on spectrum-sensitive cognitive radio, which is simpler. The main obstacle to cognitive radio, however, is the design of a high quality detection device and accompanying algorithms for exchanging spectrally scanned data between different nodes, since simple energy detectors cannot guarantee accurate signal detection.