Cooperative sensor solution to enhancing the performance of spectrum sensing

Cognitive radio (CR) is a promising technology for future wireless networks. In order to reduce the interference to primary system, CR users have to detect the spectra with low overhead and reliably in sensing slots, which has to occupy part of the available resources. In this paper, we propose a novel spectrum sensing solution that is based on cooperative wireless sensors to detect and collect available channels information and then establish a regional database managing regional spectrum information. We classify wireless sensors into relay wireless sensors (RWSs) and ordinary wireless sensors (OWSs), considering the diversity of multi-sensors and Cooperative Amplify-and-Forward (CAF) spectrum detection and CRC-based Decode-and-Forward (CDF) cooperative result reporting. Soften hard combination mechanism is proposed to further enhance the performance of spectrum sensing with one-bit overhead. If observed signals in OWSs fall in uncertain energy region, OWSs relay the signals to RWSs by CAF, otherwise, OWSs report the detection results to RWSs and then RWSs relay to Cognitive Radio Bastion (CR-BS) by CDF. Simulations show that spectrum sensing performance is improved by means of the two-layer sensing mechanism.