Ergodic Capacity Analysis for Underlay Cognitive Radio System

Cognitive radio technology has been proposed as a viable solution to the spectrum scarcity problem faced by world today. The technology allows opportunistic spectrum access to the licensed frequency band by unlicensed user without causing any harmful interference to the licensed primary user. In this paper, ergodic channel capacity is investigated for underlay spectrum sharing system under maximum and received power constraint at licensed primary receiver. The time varying discrete time fading channels are assumed to undergo Rayleigh flat fading environment. Numerical simulations have been done to support theoretical results.