Design of network coding functions in multihop relay networks

A wireless relay network with two sources, one relay, and one destination is considered. In case of erroneous source-relay links, reliability information about the coded bits in terms of log-likelihood ratios (LLRs) is transmitted from the relay to the destination. We introduce a transmission strategy for the reliability information at the relay. In contrast to other popular transmission methods (analog transmission, transmission via soft bit), our approach is motivated by a rate distortion problem for the LLRs obtained at the relay.