Double thresholds for judgment in cognitive spectrum sensing

In cognitive radio system, secondary users should have capability of detecting the signal from primary user to evade interfering harmfully with any primary receiver. The duration used for spectrum sensing influences the performance of secondary user system. In this paper, we show disadvantages of one threshold judgment in cognitive radio spectrum sensing. For improving this defect, we propose a double thresholds scheme and prove this scheme indeed could gain more throughputs under certain condition. Additionally, two instantiations are taken for general illustrating that our scheme performs better than traditional judgment at the conditions shown in these two examples. It is proved this condition is satisfied universally in cognitive radio system. Results indicate the maximal throughput increases while adopting our judgment scheme when parameters meet the condition.