Hybrid coding: A new paradigm for relay communication

Motivated by recent advances in joint source-channel coding over networks, hybrid (analog/digital) coding has been proposed as a coding technique for discrete memoryless relay networks, whereby each relay transmits a symbol-by-symbol function of the received sequence at the channel output and its quantized version (analog-to-analog/digital interface). For a few simple channel models, it has been demonstrated that hybrid coding unifies both amplify-forward and noisy network coding and can strictly outperform both. This paper extends these results to the class of general layered relay networks and establishes the hybrid coding lower bound on the capacity for the class.