Systematic lossy source/channel coding

Shlomo Shamai, Sergio Verdú, Ram Zamir

Research output: Contribution to journalArticlepeer-review

196 Scopus citations


The fundamental limits of "systematic" communication are analyzed. In systematic transmission, the decoder has access to a noisy version of the uncoded raw data (analog or digital). The coded version of the data is used to reduce the average reproduced distortion D below that provided by the uncoded systematic link and/or increase the rate of information transmission. Unlike the case of arbitrarily reliable error correction (D → 0) for symmetric sources/channels, where systematic codes are known to do as well as nonsystematic codes, we demonstrate that the systematic structure may degrade the performance for non vanishing D. We characterize the achievable average distortion and we find necessary and sufficient conditions under which systematic communication does not incur loss of optimality. The Wyner-Ziv rate distortion theorem plays a fundamental role in our setting. The general result is applied to several scenarios. For a Gaussian bandlimited source and a Gaussian channel, the invariance of the bandwidtlnsignal-to-nosie ratio (SNR, in decibels) product is established, and the optimality of systematic transmission is demonstrated. Bernoulli sources transmitted over binary-symmetric channels and over certain Gaussian channels are also analyzed. It is shown that if nonnegligible bit-error rate is tolerated, systematic encoding is strictly suboptimal.

Original languageEnglish (US)
Pages (from-to)564-579
Number of pages16
JournalIEEE Transactions on Information Theory
Issue number2
StatePublished - 1998

All Science Journal Classification (ASJC) codes

  • Information Systems
  • Computer Science Applications
  • Library and Information Sciences


  • Gaussian channels and sources
  • Rate-distortion theory
  • Source/channel coding
  • Systematic transmission
  • Uncoded side information
  • Wyner-Ziv rate distortion


Dive into the research topics of 'Systematic lossy source/channel coding'. Together they form a unique fingerprint.

Cite this