On Superposition Coding for the Wyner-Ziv Problem

TL;DR

This paper analyzes superposition coding for the Wyner-Ziv problem, demonstrating its theoretical achievability of the bound through random coding analysis and discussing practical implementation challenges.

Contribution

It extends superposition coding techniques to source coding with side information at the decoder, providing a new achievability proof for the Wyner-Ziv bound.

Findings

Superposition coding achieves the Wyner-Ziv bound via random coding analysis.

The approach can be interpreted as a multiple-access problem with successive interference cancellation.

Practical implementation issues are discussed.

Abstract

In problems of lossy source/noisy channel coding with side information, the theoretical bounds are achieved using "good" source/channel codes that can be partitioned into "good" channel/source codes. A scheme that achieves optimality in channel coding with side information at the encoder using independent channel and source codes was outlined in previous works. In practice, the original problem is transformed into a multiple-access problem in which the superposition of the two independent codes can be decoded using successive interference cancellation. Inspired by this work, we analyze the superposition approach for source coding with side information at the decoder. We present a random coding analysis that shows achievability of the Wyner-Ziv bound. Then, we discuss some issues related to the practical implementation of this method.