Performance evaluation of energy efficient Cooperative spectrum sensing in cognitive Radio networks

Abstract

With the rapid escalation of wireless communication, there is a wide amount of growth in demand for electromagnetic spectrum which in turn, results in the demand of Radio traffic intensity. Most of the radio frequency spectrum are not utilized efficiently which is found in different independent measurement campaigns and regulatory bodies in the world including the Federal Communications Commission (FCC) in the United States and the United Kingdom. The frequency bands such as military, amateur radio and paging frequencies are insufficiently utilized but other frequency bands such as cellular network bands are overloaded in most of the parts of the world and it depicts that spectrum utilization depends on time and place. The scarcity of radio spectrum has become a challenge for the conventional fixed spectrum assignment policy. Hence, cognitive radio is one of the proficient solutions to address this problem. newlineCognitive radio helps to improve the spectrum utilization by using the secondary user without causing interference to the primary user. The operation of Cognitive radio depends on reliable spectrum sensing. The performance of Cognitive radio depends on the spectrum sensing method. The performance of Cognitive radio can be improved by selecting the suitable sensing method. Development of efficient spectrum sensing techniques for mobile user is essential. The nodes are communicated through wireless, the node cannot access the access point directly which leads to hidden node problem. Shadowing is the signal fluctuation due to obstruction of the propagation path. Fading occurs when there is variation of attenuation of a signal and it should assist to reduce the hidden node problem, shadowing and fading effects. The primary objective of this thesis is to analyze three different spectrum sensing schemes namely periodic spectrum sensing, compressed wideband spectrum sensing and relay based spectrum sensing to enhance the performance of a cognitive radio. Consequently, the objectives of the thesis have been established in three phases newline