Cognitive Radio Based on Software Defined Radio

It is commonly accepted that the wireless spectrum is the scarce resource in wireless communications. However, more than 95% of the usage is below 3GHz. The static assignment of the spectrum results in inefficient usage of the spectrum. The utilization of the spectrum can be as low as 10%. Dynamic access to the spectrum can be considered as a method for solving spectrum scarcity. Cognitive Radio and Dynamic Spectrum Access represent two complementary developments that will refashion the world of wireless communication. In order to investigate the roles of knowledge representation and reasoning technologies in this domain, we have developed an experimental cognitive radio simulation environment. That is, a conventional radio when operating in a particular communications mode always follows the same procedure and either succeeds or fails at a given task. This paper represent the spectrum sensing of Cognitive radio using matlab software. A cognitive radio, by contrast, can use knowledge of radio technology and policy, representations of goals, and other contextual parameters to reason about a failed attempt to satisfy a goal and attempt alternate courses of action depending upon the circumstances. Finally, the results shows the power spectral density of the channel which can be used cognitively to find out the available gaps those can be assigned to new incoming users thus improving the overall channel’s throughput.