Cooperative Spectrum Sensing Using Individual Sensing Credibility and Hybrid Quantization for Cognitive Radio

Abstract

Cognitive radio (CR) has been considered as one of promising next-generation communication systems owning to its ability of sensing and making use of vacant channels that are currently unused by licensed user. Reliable spectrum sensing of licensed users is required for CR network to minimize interference to licensed users. However, due to the effects of the channel fading and shadowing, individual cognitive radio may not able to reliably detect the presence of a licensed user. Cooperative spectrum sensing has been proposed for improving sensing performance of CR network based on the cooperation of CR users in sensing signal from the license user. In this paper, we propose a cooperative spectrum sensing scheme using individual credibility and hybrid quantization for cognitive radios in order to improve sensing performance of global sensing performance and reduce communication traffic between CR users and the Fusion Center (FC). In the proposed scheme, few local sensing information that satisfies the credibility condition will be quantized using hybrid quantization scheme and further being reporting to the FC. The hybrid quantization scheme proposed in this paper can enhance sensing performance and reduce reporting bits of the sensing process based on the various numbers of quantized bits.