Opportunistic Cooperative Communication in the Presence of Co-Channel Interferences and Outdated Channel Information

This paper investigates the impacts of co-channel interference and outdated channel state information (CSI), two main issues in practical operating environment, on the performance of opportunistic decode-and-forward cooperative networks. First, the distribution function of the effective signal-to-interference-plus-noise ratio at the end receiver is derived. Then, exact closed-form expressions for the error and outage probabilities are obtained. Furthermore, simple asymptotic expressions for the error probability, which explicitly show the coding and the diversity gains, are derived and discussed. In particular, it is demonstrated that the diversity order of the system is reduced to unity when CSI is outdated, and to zero when the ratio of the interference energy to the signal energy is constant.