基于能量和协方差的两步频谱感知

频谱感知是认知无线电中的一项关键技术,主要功能是能够快速准确检测出频谱中是否存在授权用户。频谱感知的能量检测算法简单,但在低信噪比情形下的检测性能不佳,而协方差算法在低信噪比环境下具有较好检测性能。针对上述情况提出了一种这两步相结合检测的算法,从而具有更准确的频谱感知性。仿真结果表明,两步检测算法在低信噪比情况下无需授权用户的先验信息,同时使算法的平均计算量相对于协方差算法有一定程度的降低,并能有效地提高频谱感知性能。

Scheme of Two-step Spectrum Sensing Based on Energy and Covariance

The spectrum sensing is one of the key technologies for cognitive radio,which can detect whether the authorized user exists or not in the spectrum,quickly and accurately.The energy detection algorithm is simple,but its detection performance is poor in low SNR,while the covariance algorithm having a good detection performance in the case of low SNR.Aiming at the above problem,this paper proposes a two-step detection for the spectrum sensing.The simulation results show that the two-step detection algorithm does not require the priori information of authorized user,and the average computation can be reduced to a certain extent with respect to that of covariance algorithm,thus improving the performance of spectrum sensing in low SNR.