Outage Probability of Cognitive Selective DF Relay Networks with Multiple Primary Nodes and Heterogenous Non-Identical Constraints

Outage probability analysis of cognitive selective DF relay networks with selection combining technique taking into account all the following issues is important: multiple SU relays, multiple PUs, non-identical independent Rayleigh fading channels, non-identical interference power limits of PUs, non-identical maximum transmission power limits of SUs, and non-identical noise powers in signals. However, no existing works solve this task exactly. In this paper, to overcome the complexity in analyzing such non-identical-parameter networks directly, we conduct the analysis in two steps indirectly. In the first step, we obtain outage probability expressions of identical-parameter networks. Then in the second step, we propose a method for transforming a non-identical-parameter network into a new identical-parameter network, meanwhile guaranteeing that the distributions of end-to-end signal to noise ratio of the two networks before and after the transformation are identical. Thus the outage probability of the identical-parameter network can be regarded as outage probability of the corresponding non-identical-parameter network. Numerical simulations validate our analysis results and confirm the feasibility of the two-step indirect analysis approach.