Abstract: The primary task of cognitive radio is dynamically sensing spectrum. Cooperative spectrum sensing increases the reliability of spectrum sensing. Recently most spectrum sensing algorithm uses all the cognitive radio to participate in the sensing and assumes the SNR measured values of each cognitive radio as a constant. However, because the characteristics and environment of wireless channel have difference, the SNR of each cognitive radio is difference and system resources arc also limited. Based on this, we proposed an optimized spectrum sensing algorithm on the foundation of cooperative spectrum sensing which uses hard decision. It can use partial of cognitive radio to participate in spectrum sensing and minimize the sensing overhead. The analytic results were verified by computer simulation.

Key words: False alarm probability, Hard decision, Sensing ovcrhcad, Resource constrained