Joint optimization of sensing time and decision thresholds for wideband cognitive OFDM radio networks

Cognitive radio (CR) has the ability to sense the wireless channel and make use of the vacant spectrum bands. One of the main challenges in CR systems lies in striking a balance between the conflicting goals of minimizing the interference to the primary user (PU) and maximizing the performance of all secondary users (SUs). A joint optimization strategy of sensing time and decision thresholds for wideband cognitive orthogonal frequency division multiplexing (OFDM) radio networks is proposed in this paper. The strategy can maximize the opportunistic throughput of all SUs with subjection to the interference constraint under practical conditions. From simulation results we find that optimizing the sensing time and decision thresholds play a key role in maximizing the system throughput.