Método de detección de usuarios primarios utilizando una descomposición wavelet

Abstract

The sensing function is one of the most important features of cognitive radios since a reliable detection of available spectrum ensuring non-interference to licensed users is necessary to initiate a lower priority communication. In this paper, the proposal of a physical layer sensing method using the multiple-level wavelet decomposition analysis for the detection of primary users is presented. The proposed scheme consists of four stages (sampling, multiple-level decomposition analysis, coefficients analysis and evaluation criterion), where the energy percentage through the decomposed levels is proposed as a metric to determine if there is a high priority user present on the channel or not. For simulation purposes different input signals involving the presence/absence of a primary user as well as variations in the SNR were considered in order to evaluate the model.