A Fusion Decision Algorithm Based on Channel Estimation in Cognitive Radio System

Fusion decision plays an important part in the cooperation sensing of cognitive radio. In this paper, a fusion decision algorithm based on channel estimation (FD_CE) is proposed in the architecture of central cooperative sensing in cognitive radio. Instead of the traditional hard decision methods such as AND, OR, Most, we consult to a soft decision algorithm which combines all the detected information of different secondary user (SU) by a linear weight of their channel gains. The algorithm proposed has evaluated the reliability about each secondary user's radio environment, so it brings a better sensing performance. Simulation results show that a higher probability of detection can be achieved using the proposed algorithm comparing with single node sensing, cooperative sensing by AND and OR rules; meanwhile, it decrease the detection threshold effectively at the same time, which means saving single node's hardware cost in other words.