An efficient cooperative spectrum sensing scheme in cognitive networks

In cognitive radio systems, cooperative spectrum sensing among cognitive users is necessary in order to increase the reliability of detection. However, when the number of cognitive users tends to be very large, the system overhead for reporting their sensing results to the common receiver will be huge. In this paper, we present a novel efficient cooperative spectrum sensing scheme based on orthogonal waveforms design. By designing mutual orthogonal waveforms for different sensing bits, all the users are allowed to transmit their sensing information simultaneously on the same available band. Analytical results demonstrate that it can significantly outperform TDMA and FDMA schemes on the improvement of the transmission efficiency, especially for large-scale CR networks.