Abstract
Spectrum sensing is a key function in the cognitive radio networks. It allows cognitive users to check the existence of the primary user in the frequency radio and use the channel if the channel is vacant to achieve high spectrum usage efficiency. Blind spectrum sensing is widely discussed because it does not need prior knowledge of the primary user. Many researchers have proposed different blind sensing algorithms and each has its advantages and disadvantage. For example, the energy detector performs well with low complexity but has the problem of noise uncertainty, and the maximum-to-minimum eigenvalue method does not need to know the noise power but with high complexity. Inspired by the maximum-to-minimum eigenvalue method, we proposed a correlation-based method exploiting the channel correlation under Rayleigh fading channel. Simulation shows the improvement of the correlation-based method toward energy detector and the maximum-minimum eigenvalue method. Analytical expressions are also derived.