Efficient Multiple Access Protocols for Coded Multi-Source Multi-Relay Networks

We study the impact of multiple access protocols on the diversity-multiplexing tradeoff (DMT) performance in wireless multi-user relay networks. In the networks K half-duplex decode-and-forward (DF) relays employ a class of finite field network codes to assist in the communication between M independent sources and a common destination. The sources and relays are divided into individual clusters. The nodes within one cluster transmit non-orthogonally while the transmissions of different clusters span orthogonal channels. We provide the method to calculate the achievable DMT for each clustering strategy. The network DMT performance can thus be optimized by properly clustering the sources and the relays.