Communication Protocols for N-way All-Cast Relay Networks

We consider communication protocols for N-way all-cast relay networks, which comprise N source terminals such that each source terminal demands messages from all other source terminals with the help of a relay. The derived protocols are characterized by the fact that physical layer network coding is employed at the relay, where each source has side information about the signals it has sent. Amplify-and-forward (AF) and decode-and-forward (DF) protocols are applied to the N-way relay network setting, where the achievable rate regions for those protocols are derived and compared with outer capacity bounds. We propose several practical space-time coding schemes for AF and DF, and introduce two new protocols denoted as denoise-and-forward (DNF) and estimate-and-forward (EF). Further, for AF and DF the fundamental diversity-multiplexing trade-off is characterized.