An Improved Multitaper Method for Spectrum Sensing in Cognitive RadioNetworks

摘要

Spectrum sensing is one of the most basic issues in cognitive, radio (CR), upon which the other operations to increase the spectrum utilization could be carried out. Therefore, an accurate, reliable and real-time method to detect the unused spectrum and available bands is required urgently. To fulfill the needs, several schemes have been introduced, among which the multitaper method (MTM) for nonparametric spectrum estimation is the most appealing. In the paper, we propose an improved method based on MTM, making the detection more effective and robust. To concentrate the power in a fixed bandwidth, Slepian sequences have been employed in MTM, and it has a good performance when only using the low-order tapers. But as the number of tapers increases, it hardly works well. Consequently, the adaptive weighting MTM (AW-MTM) are proposed to solve the problem. Numerical results show that AW-MTM has a much better performance than conventional methods for spectrum sensing in CR.