Cooperative regions for coded cooperative systems

Cooperation of mobiles provides signal diversity in wireless networks. In this paper, we consider a coded cooperative system under Rayleigh fading and path loss. For an arbitrary signal to noise ratio, we find conditions on the user geometry for two-user cooperation to be beneficial. We find that whether cooperation is useful or not is only determined by the cooperation decision parameter (CDP). We illustrate regions for which cooperation results in a gain in Frame Error Rate (FER) for individual users and use the analytical formulation of the CDP to investigate how locations of the user and the partner affect the user cooperation gain. Our analytical results also provide insights on how a user can choose among many partners to maximize cooperation gain. All of our theoretical results are verified by numerical simulations of the FER.