Multi-group multi-way relaying with multi-stage non-regenerative relay stations

This paper deals with a new decentralized observer-based controller design method for nonlinear discrete-time interconnected systems with nonlinear interconnections. Thanks to some algebraic transformations and the use of a new variant of Young\u27s inequality, an LMI-based approach is provided to compute the observer-based controller gain matrices. Furthermore, the congruence principle is used under a judicious and new manner leading to include additional slack variables and to cancel some bilinear matrix coupling. The effectiveness of proposed methodology is shown through an illustrative example