Spectrum Sensing for Cognitive OFDM System Using Free Probability Theory

摘要

Free probability theory as a main branch of random matrix theory is a valuable tool for describing the asymptotic behavior of multiple systems, especially for those with large random matrices. In this paper, by using free probability theory, a new spectrum sensing scheme for cognitive OFDM system is proposed, which shows how asymptotic free behavior of random matrices and the property of Wishart distribution can be used to assist spectrum sensing for cognitive radios in such scenario. Simulation results show that the proposed scheme has a better detection performance than the energy detection technique and the maximum-minimum eigenvalue scheme even for the case of a small sample of observations.