Weighted-Cooperative Spectrum Sensing Scheme using Clustering in Cognitive Radio Systems

Cognitive radio is an advanced technology for efficient utilization of under-utilized spectrum since it is able to sense the available spectrum and use empty frequency bands if there is no use of primary user. These sensing observations are forwarded a cognitive radio base-station through fading channels, the sensing performance will be severely degraded. In order to mitigate this effect, weighted-cooperative sensing was considered to be a promising way in our previous work, which combines the sensing result of each CR user to improve the performance. However, in practical, the probability of detection is unavailable to calculate in each user. In this paper, we propose a weighted-cooperative sensing scheme using clustering to improve the performance and to overcome the critical problem. Numerical results show that the sensing performance is improved obviously as opposed to conventional spectrum scheme.