Exact outage analysis of modified partial relay selection in cooperative cognitive networks under channel estimation errors

Abstract

This study first modifies the traditional partial relay selection in cooperative cognitive networks to prevent error propagation and then proposes exact and asymptotic outage analysis for the modified partial relay selection under practical operation conditions such as channel estimation errors (CEEs) on all wireless channels, independent and non‐identical fading distributions, interference power constraint, and maximum transmit power constraint. The proposed analysis is useful in assessing system performance in important parameters as well as providing insights into performance limits without exhaustive simulations. Moreover, in order to quantitatively evaluate the performance gain of utilising the direct channel between the source and the destination in relaying communications, the authors extend their proposed analysis to dual‐hop cognitive networks. Illustrative results demonstrate that CEEs and outage threshold significantly degrade system performance, and the direct channel dramatically contributes to performance improvement of relaying communications.