Performance Evaluation of Spectrum Sensing Under PU Random Access

Avoiding of interference to the licensed users is the major concern of cognitive radio technology. Spectrum sensing is the function that senses licensed user behavior in the channel. Generally, existing spectrum sensing senses the channel status when PU exists in the sensing period. Once PU accesses or leaves the channel randomly, the number of samples that contain PU signal reduces. Then, the energy of detected signal may be lower than predetermined and the spectrum sensing may present unreliable result. In this paper, we evaluate the effect of PU behavior on the licensed channel according to traditional and alternative solutions of spectrum sensing. Then, the simulation results show that traditional techniques are unreliable when PU accesses or leaves the channel during sensing period while alternative techniques can address the random access issue.