Secondary user capacity maximization in CR under nakagami-m fading channel with receiver diversity

Abstract

In Cognitive Radio scenario achieving maximum secondary user capacity has always been a challenging task along with high detectability of primary user. Detection of primary user signal in presence of noise and channel fading condition is very conveniently carried out by energy detection scheme due to its less complexity in its structure. Further, for improving system performance under limited bandwidth control-channel we employ double threshold energy detection scheme. In this paper we assume the sensing channel as Nakagami-m fading type to calculate optimum level of threshold in decision region and SNR level of primary user signal for required probability of detection while treating reporting channel to be ideal. We observe the effect of varying optimum level of threshold on normalized capacity of secondary user along with SNR level of primary user for MRC diversity scheme. Numerical results show that increasing the threshold in decision region decreases the probability of detection of primary user and increases the normalized capacity of secondary user.