Improving Channel Utilization via Cooperative Spectrum Sensing With Opportunistic Feedback in Cognitive Radio Networks

As the number of sensing nodes increases, cooperative spectrum sensing increases the detection probability of primary users at the cost of increased bandwidth of feedback channels. However, the excess feedback overhead of reporting sensing results may degrade the channel utilization of cognitive radio networks. This letter proposes cooperative spectrum sensing with a fixed number of feedback channels, where each sensing node opportunistically reports its sensing result to a fusion center via shared feedback channels only if its sensing result is greater than a threshold. The simulation results show that the proposed cooperative spectrum sensing increases the channel utilization with limited feedback overhead compared with the conventional cooperative spectrum sensing.