摘要：Cognitive radio (CR) technology aims to achieve efficient radio spectrum utilization based on overlay spectrum sharing. Therefore, one of the main requirements of CR systems is the capability to detect and sense the presence of primary transmissions. However, sensing is affected by the behavior of the wireless channel, i.e., hidden node, interference, shadowing, and fading, which may result in wrong detection decisions. Consequently, CRs may introduce harmful interference to primary radios. Cooperative spectrum sensing can improve detection decisions by obtaining sensing information from different sources, which has been recently proposed to overcome this problem. This paper reviews cooperative sensing aspects, approaches, architecture, as well as problematic aspect and drawbacks of the control channel and associated fusion methods.
