Cognitive Radio—the Basics

Cognitive Radio according to Wikipedia is the dynamic modification of the RF signal based on the spectrum, the user behavior, or the state of the network. It’s the logical next step after software defined radio in which the radio usage adjusts to the user and network’s needs. The idea here is that some parts of the spectrum are underutilized. By using cognitive radio techniques, unlicensed users can make use of licensed frequencies that have unused capacity—which is called Licensed Band Cognitive Radio.

There are variations of cognitive radio. The first is called Spectral Sensing Cognitive Radio in which only the radio frequency is monitored. Spectral sensing has been applied to TV channels in order to provide more bandwidth for high definition as well as emergency networks. The technique requires more than just detecting the energy in a channel. It requires a series of nodes to exchange information which is why research is moving towards Cognitive Networking.

The four main functions of Cognitive Radio are

1. Spectrum sensing –finding unused spectrum.
2. Spectrum management – finding the best available spectrum to use based on quality of service criteria.
3. Spectrum mobility –allowing for the shift from one frequency to another
4. Spectrum sharing – scheduling and sharing spectrum in a fair manner


Best regards,
Hall T.