Polar coding for relay channels

Polar coding schemes are developed for the decode-forward relaying (digital-to-digital interface) and the compress-forward relaying (analog-to-digital interface) in the three-node relay channel. For decode-forward, a technique based on the recent universal polarization method is applied to create the desired nested structure. For compress-forward, existing methods are generalized to allow arbitrary input distributions and channel statistics. Both schemes achieve full theoretical rates in general relay channels.