A collaborative channel sensing method based on the energy detection for multi-users in cognitive radio systems

摘要

PURPOSE: A cooperative channel sensing method based on energy detection for multi-users in a CR(Cognitive Radio) system is provided to perform the statistical modeling of influence on energy detection of a relative distance and fading gain among a first user and second users and give a different weight to each second user, thereby improving the accuracy of channel sensing. CONSTITUTION: Probability distribution about received energy is calculated based on probability distribution about a distance between a pre-order user and a post-order user and probability distribution about multi-route fading gain(S430). A likelihood ratio is calculated based on the calculated probability distribution about the received energy(S440). The occupation of spectrum is decided by comparison between a threshold value and the calculated likelihood ratio(S445~S455).