Cooperative Spectrum Sensing under Imperfect Channel Estimation

Recently proposed cooperative spectrum sensing method suggests that Cognitive Radio (CR) users can detect the primary users at low SNR with less time and higher accuracy through user cooperation. However, previous works assume CR users can acquire fully channel state information by pilot symbols, which is impractical. In this paper, the performance with imperfect channel estimation in cooperative spectrum sensing method is analyzed and the trade-offs between false alarm probability and leakage alarm probability on the decision of threshold under imperfect channel estimation is presented. Simulation results show that the imperfect channel estimation would reduce the benefits obtained from cooperation. When estimation error grows to 0.3 there would be a 0.11 loss in detection probability and the false alarm probability, which is important to CR system, would increase from 0.1 to 0.4.