Improving joint detection of the spectrum by separation in time and frequency domains in cognitive radio

Sections 1 through 3 explain the improvement mentioned in the title, which we believe is new and better than previous methods of detection. Their core consists of; "In cognitive radio systems, users require an accurate and real-time judgment. But it is usually confronted by great difficulities if the user stations are in severe fading or interference. We first analyze the performance of energy detection and find it greatly descreased with high noise fluctuation, especially when the SNR is very low. Cyclostationary detection is more reliable but more time is needed related to energy detection. We propose to divide the decision area. Then we further use cyclostationay detection in the confused area to get more reliable results. The final result is obtained by the fusion of these two detection results. Fig. 1 in section 3 is a flowchart for decision making in joint detection. " Simulation results, presented in Figs. 2 through 4, and their analysis show preliminarily that the joint detection can indeed improve the precision and reduce the time consumption effectively, especially when the spectrum is wide and the needed detection time is very long.