We study the problem of communication over an additive white Gaussian noise
(AWGN) channel with an AWGN feedback channel. When the feedback channel is
noiseless, the classic Schalkwijk-Kailath (S-K) scheme is known to achieve
capacity in a simple sequential fashion, while attaining reliability superior
to non-feedback schemes. In this work, we show how simplicity and reliability
can be attained even when the feedback is noisy, provided that the feedback
channel is sufficiently better than the feedforward channel. Specifically, we
introduce a low-complexity low-delay interactive scheme that operates close to
capacity for a fixed bit error probability (e.g. $10^{-6}$). We then build on
this scheme to provide two asymptotic constructions, one based on high
dimensional lattices, and the other based on concatenated coding, that admit an
error exponent significantly exceeding the best possible non-feedback exponent.
Our approach is based on the interpretation of feedback transmission as a
side-information problem, and employs an interactive modulo-lattice solution.

研究 AWGN 通道反馈通道下的通信问题，提出了一种低延迟低复杂度的交互式方案，以及两种渐进构造方法，该方法基于反馈传输的解释和交互模 lattice 解决方案。