多用户协作频谱感知的性能分析

实际的无线信号传输会受到阴影效应、噪声等因素的影响,单个认知用户的频谱感知性能会下降。因此,采用硬合并协作方案,分析了多用户协作感知在高斯、瑞利和莱斯信道下的检测性能。同时,对控制信道由于衰落和噪声影响而产生误码情况下的系统检测性能进行探讨。结果表明,多用户协作检测可以提高系统的检测概率,但虚警概率会随着参与协作的用户数的增多而上升,当控制信道不理想时,协作检测会导致虚警概率下限的出现,造成频谱利用率低下。

Performance Analysis of Multiuser Cooperative Spectrum Sensing

In practical wireless environment,signal transmission is affected by shadow effect,noise and so on.So the spectrum sensing performance of single cognitive user declines.So the detection performance of multiuser cooperative spectrum sensing in Gauss,Rayleigh and Ricean fading channels is analyzed by using hard combination cooperative scheme.By taking into account the error effect on the control channel,we discuss the performance of cooperative spectrum sensing in fading channel.And it is tested that cooperative spectrum sensing can improve the cognitive radio system’s detection probability,but false alarm probability increases as the number of cooperative users increasing.Especially,when control channels are not reliable,low bound of false alarm probability will appear and result in decrease of spectrum utilization.