In order to improve the detection performance of cooperative spectrum sensing for cognitive radio (CR), the weighed cooperative sensing algorithm was investigated, by optimizing two sensing parameters including weight and observed time.The minimal false alarm probability was obtained by choosing the optimal weight under the given detection probability, while the optimal observed time was obtained through the proposed half searching. Simulations showed that compared to the traditional un-weighed cooperative sensing, the proposed algorithm could achieve lower false alarm probability and higher spectrum utilization, while the half searching could achieve lower computational complexity than the exhaustive searching. The results indicated that the proposed algorithm might make CR achieve the maximal spectrum utilization within the interference limit of licensed user.
