  In this work, we present a cloud-aided uplink framework for multi-way
multiple-antenna relay systems which facilitates joint linear Maximum
Likelihood (ML) symbol detection in the cloud and where users are selected to
simultaneously transmit to each other aided by relays. We also investigate
relay selection techniques for the proposed cloud-aided uplink framework that
uses cloud-based buffers and physical-layer network coding. In particular, we
develop a novel multi-way relay selection protocol based on the selection of
the best link, denoted as Multi-Way Cloud-Aided Best-User-Link
(MWC-Best-User-Link). We then devise the maximum minimum distance relay
selection criterion along with the algorithm that is incorporated into the
proposed MWC-Best-User-Link protocol. Simulations show that MWC-Best-User-Link
outperforms previous works in terms of average delay, sum-rate and bit error
rate.
