A unified framework for performance analysis of DF cognitive relay networks under interference constraints

In this paper, we present a unified performance analysis for cognitive cooperative communication systems. In particular, the system performance in terms of outage probability (OP) for three cooperative protocols, i.e. fixed decode-and-forward (DF) relaying (FR), selective DF relaying (SR), incremental DF relaying (IR), under interference constraints, is derived over dissimilar Rayleigh fading channels corrupted by additive white Gaussian noise. The closed-form, integral-free, OP readily enables us to evaluate the cognitive cooperative system performance, which indicates the significance of using relay in cognitive environment. To verify the analytical results, we provide some selected Monte Carlo simulations and the performance comparison of these protocols at the end.