Cognitive radio permits unlicensed users to access licensed frequency bands through dynamic spectrum access so as to reduce spectrum deficiency. This requires intelligent spectrum sensing techniques like co-operative sensing which creates use of information from number of users. The main challenge in any cognitive radio system is to maximize secondary user’s throughput while limiting interference imposed on licensed users. In this consideration finding the optimal sensing and transmission timing strategies and accurate sensing techniques are of great importance in a cognitive radio network. In this paper, examine different on Matched filtering, Energy detection and Cyclostationary feature detection cognitive radio spectrum sensing techniques over AWGN channel. It also contain combined analysis of Matched filtering, Energy detection and Cyclostationary feature detection technique for common scenario through decision accuracy vs SNR plots over Nakagami-m Fading Channel , Rician Fading Channel.