Solution of Information Exchange for Cooperative Sensing in Cognitive Radios

Recently, cooperative sensing which can enhance the sensing performance becomes popular in the design of cognitive radio (CR) networks. CR networks need reliable information exchange to conduct cooperative sensing, but it is difficult to transmit information for CR networks without licensed band over the air interface. In this paper, we propose to use spread spectrum technology to transmit low rate exchange information through wide bandwidth. Simulation results show that the capacity loss of primary user is minor, while the exchange information can be demodulated and decoded at a high SNR level based on our proposed scheme. The tradeoff between detection performance and interference to primary user is also discussed.