Amplify-and-Forward Cooperative Spectrum Sensing Using Three Secondary Users for Cognitive Radio

Abstract

In the Cognitive Radio (CR) networks, Secondary Users (SUs) have to detect the presence of the Primary Users (PUs) in a fast and accurate manner and vacate the channel for the PUs. For a cooperative CR scenario, the SUs in a specific area can collaborate for enhancing the PU's detection. In this paper, we extend a previously proposed Amplify and Forward (AF) cooperative detection algorithm by increasing the number of collaborating SUs from two to three. Therefore, there are more situations for which the cooperation detection outperforms the non-cooperative scenario. We analyze the Energy Detection (ED) probability of the cooperative algorithm both theoretically and using simulations. In order to facilitate the analysis, we propose a simple power-law path loss channel model that relates the distance between users to the channel gain. Therefore, in a typical cooperative scenario, we demonstrate a detection probability increase between 7.7% and 15.6% as compared to the noncooperative scenario.