Spectrum sensing in cooperative networks using relay forwarding techniques

Abstract

Wireless communication is an integral part of modern society and the wireless communication techniques are being extensively researched. The wireless mobile users are increasing every day and the wireless spectrum is becoming scarcer by the day. But studies show that this spectrum is not utilized to its full potential. Cognitive radio is a technique which allows unlicensed users to use the spectrum hence increasing spectrum efficiency. Main task of a cognitive radio is to sense that when should he use the spectrum, this is called spectrum sensing. Many spectrum sensing techniques have been developed and in this thesis, the focus is on two things: Adaptive Energy Detection and Cooperative Spectrum Sensing. The probability of detection is studied for simple energy detection and adaptive energy detection and their result is compared. Than both these algorithms are simulated in a cooperative spectrum sensing environment using AND, OR and Majority rule. Then, these cooperative spectrum sensing rules are studied for 1, 2 and 3 cooperative nodes using Receive and Forward and Decode and Forward. Then, the probability of detection and probability of error for all techniques are compared. In a nutshell, this work highlights the superior performance of Adaptive Threshold Energy Detection over the conventional Fixed Threshold Energy Detection and Cooperative Spectrum Sensing over Direct Path Spectrum Sensing.