A weighted fusion scheme for cooperative spectrum sensing based on past decisions

Cooperative spectrum sensing is employed in cognitive radio networks to reliably detect the primary users´ transmissions by fusing the sensed data of individual secondary users. In this paper, we propose a new weighted fusion scheme, in which the reliability of the secondary users´ local decisions are considered when making a final decision at the fusion center. We use past information about the local and global decisions to estimate the reliability of the sensing decision obtained from each secondary user. This difference in reliability is reflected in the weighting of each secondary user´s decision when combined at the fusion center. Simulations are provided to compare the performance of the proposed scheme to the OR, AND, Equal Weight and Signal-to-Noise Ratio (SNR) based Weight fusion schemes. Results show that our proposed scheme provides performance improvement for cooperative spectrum sensing when compared to the other fusion schemes.