为提高认知无线电系统中频谱检测的可靠性,提出了一种基于能量检测的协作式频谱感知算法。利用授权用户的状态在相邻感知帧之间变化的概率小这一特性,通过将当前感知帧的能量值与相邻值相结合来判断授权用户状态,这样当授权用户使用授权频段时,所提算法能有效减小采样信号能量值骤减时发生误判的概率。另外给出了所提算法检测概率和虚警概率的闭式表达式。理论分析和仿真结果表明,所提算法比传统的协作式频谱检测算法检测性能好。
To improve the reliability of spectrum sensing in cognitive radio system, a new cooperation spectrum sensing algorithm was proposed. In this algorithm, the property of the low probability between adjacent frames of the states change was used and then the decision was made by combing the energy value of the current sensing frame with that of the neighboring frame. Therefore, the proposed algorithm could decrease the miss detection probability in case of the instantaneous signal energy dropping when primary user used the licensed spectrum. Furthermore,theoretical expressions for detection probability and false alarm probability were derived. Finally, theoretical analysis and simulation results verify that the detection performance of the proposed algorithm is better than that of cooperative spectrum sensing which is based on the classical energy detection.