Threshold selection for energy detection in Cognitive Radio with a non-line-of-sight environment

This paper selects a reasonable threshold for energy detection in cognitive radio, where a non-line-of-sight (NLOS) environment is considered. The secondary user (SU) uses this threshold to detect whether the spectrum is occupied by the primary user (PU) or not. Three specific NLOS scenarios are depicted and analyzed in this paper. In order to improve the existing threshold value in energy detection for a LOS environment, we need to consider the specific path loss through different obstacles. Different path loss exponents are considered to represent different obstacles and used to calculate the path loss. The improved threshold value is then obtained based on the updated path loss. Computer simulations demonstrate our proposed method.