MIMO multiuser cognitive relay network in spectrum sharing environment with antenna correlation over Rayleigh fading channels

In this paper, we examine the impact of antenna correlation on transmit antenna selection with maximal ratio combining (TAS/MRC)in multiple-input-multiple-output multiuser cognitive relay networks (MIMO-MCRNs). A single secondary user (SU) source communicates with M SU destinations via SU decode-and-forward (DF) relay over Rayleigh fading channels and in the presence of L PU destinations. Each node in the considered SU network is equipped with multiple correlated antennas as well as the L PU destinations. The SU network employs underlay spectrum sharing paradigm in which the SU transmission power is limited by peak interference temperature limit on the PU network and the maximum allowable transmission power at each node of the SU network. As a measure of performance, we derived an exact expression for the outage probability of the proposed SU network. To gain further insights, a simple asymptotic expression for the outage probability is provided to obtain the achievable diversity order and coding gain.