Outage Probability of SINR for Underlay Cognitive Radio Systems in Nakagami Fading

Abstract

In this paper underlay cognitive radio system is analyzed in Nakagami fading environment, for the case when the available channel state information (CSI) of the link from the secondary transmitter to the primary receiver is outdated. We considered the case when both interference and transmit power constraints are applied. The impact of the co-channel interference that originates from the primary user is analyzed in details. The exact closed-form expressions for probability density function, outage probability, and the moments of signal-tointerference and noise ratio (SINR) at the secondary user's receiver are derived. The analytical expressions are verified by using independent Monte Carlo simulation method.

Performance Analysis of Underlay Cognitive Radio System with Self-Sustainable Relay and Statistical CSI

“…In the underlay cognitive system, the CSI can be provided to the SU through cooperation with the PU (if the channel is reciprocal) or by mediation of the band-manager. However, the acquired CSI is practically always imperfect, even in the case when there is cooperation with the PU [ 6 , 7 , 8 , 9 , 10 ]. Due to the time-varying nature of the channel and the finite backward channel latency, the acquired CSI is outdated.…”

“…The performances of underlay cognitive radio with available imperfect CSI are analyzed in [ 6 , 7 , 8 ]; these works introduce the concept of interference outage, as the strict interference threshold constraint at the PU receiver cannot be satisfied. The underlay cognitive network based on statistical CSI enables lower complexity solution for coexistence with the primary spectrum user’s network [ 9 ].…”