A Study of Data Fusion and Decision Algorithms Based on Cooperative Spectrum Sensing

The cooperative operation can improve the sensing performance of cognitive radio networks and reduce the sensing time. Combining multiple cognitive users´ local detection results and making accurate judgment is essential to improve cooperative gain. According to uploaded information from cognitive users, hard decision based on the combination of large numbers and soft decision based on the confidence (maximum likelihood) combination are discussed. The single-bit hard decision algorithm, soft decision algorithm based on the maximum ratio combination, equal gain combination and selection combination, data fusion and decision algorithm based on evidence theory as well as softened 2bit hard combination and decision algorithm are mainly introduced, and detection performance and complexity are analyzed respectively.