Information theoretic analysis of MIMO cognitive radio networks

Abstract

Cognitive radios have been evolved as recent technological advancement for the efficient utilization of wireless spectrum. Spectrum sensing is amongst the most critical factors in the implementation of Cognitive Radio Network (CRN). There are different spectrum sensing techniques for cognitive radio networks. One of them is MIMO in which multiple antennas are exploited on transmitter and receiver side to combat fading, increase data rate and capacity. MIMO allow cognitive users to transmit in the null space of primary users. With the use of MIMO in CR networks probability of detection increases and the probability of false alarm decreases. In order to take maximum advantage of CRN it is very important to have the knowledge of fundamental limits of channels employing cognitive radios. Information theory is an ideal approach for this purpose. Capacity of CRN is challenged by numerous factors including fading. During propagation from transmitter to receiver, data signal undergoes multipath fading that causes degradation in the throughput of CRN. However, by exploiting channel diversity in multipath fading channel environment, performance of the system is enhanced. In this thesis, throughput of primary and cognitive radio network for the rician fading channel has been derived. Numerical results show that information capacity of the system is increased up to 8.5 bits/s/Hz.