Ergodic capacity performance for cognitive radio under lognormal shadowing from secondary user perspective

In a cognitive radio network, spectrum sensing is the first and most vital function. It identifies spectrum opportunities that can be utilized by secondary users to enhance spectrum utilization and ergodic capacity. However, sensing performance is very tormented by channel fading and shadowing. This paper addresses the performance of ergodic capacity in cognitive radio networks under a Lognormal shadowing environment. We derived a new mathematical model for the secondary user network ergodic capacity when both accessing and sensing channels undergo Lognormal shadowing. Moreover, we developed exact analytical expressions for the capacity followed by numerical evaluation under different channel sensing and accessing conditions. Finally, the paper explored the effects of detection and accessing channels’ parameters on the capacity.