The impact of time-bandwidth product on the energy detection in the cognitive radio

The cognitive radio technology is an intelligent wireless communication system, which provides the opportunity to the secondary users for sharing the spectrum resources with the primary users. The core of cognitive radio is the spectrum sensing, which means detecting the free spectrum. Energy detection algorithm is applied most widely. Among these parameters of influencing detection performance of the energy detection, the time-bandwidth product plays a decisive role. It is defined as the product of the filter bandwidth and the time of the detection. In this article, the energy detection is analyzed theoretically and simulated from the point of the time-bandwidth product. The simulation results indicate that the detection performance will be improved with the increasing value of the time-bandwidth product. This provides the possibility for using the energy detection under the lower SNR, and shows the great meanings for the actual application of the energy detection.