JCS_V6_N1_RP4 Veerendra Md. Bakhar Vani R.M. Journal on Communication Engineering and Systems 2277-5242 6 1 32 37 Cognitive Radio, Direction of Arrival (DOA), Maximum Eigen Value (MEV), Maximum Likelihood Method (MLM), Hannan-Quinn (HQ) Smart antenna systems have been studied for many years for signal detection and estimation and are used only in military applications until recently. These are becoming popular from recent years and are used in commercial applications due to impulsive advancement in the digital signal processing and VLSI technology. In array signal processing, plethora of problems related to signal detection and estimation is solved using various Direction Of Arrival (DOA) algorithms, including Bartlett, Maximum Likelihood Method (MLM), and Maximum Eigen Value (MEV) method. These algorithms and many variants of these algorithms deteriorate from its performance either for narrow angle or wide angle separation. Hence the authors proposed the DOA estimation algorithm based on Hannan-Quinn (HQ) criterion for wideband spectrum sensing in cognitive networks. Simulation results validate the effectiveness of this method. November 2016 - January 2017 Copyright © 2017 i-manager publications. All rights reserved. i-manager Publications http://www.imanagerpublications.com/Article.aspx?ArticleId=10357