Computer Science – Information Theory
Scientific paper
2010-06-10
Computer Science
Information Theory
Submitted to IEEE Transactions on Information Theory. For clarity, sections has been rewritten and several propositions has be
Scientific paper
It is well known that Shannon's rate-distortion function (RDF) in the colored quadratic Gaussian (QG) case, can be parametrized via a single Lagrangian variable (the "water level" in the reverse water filling solution). In this work, we show that the symmetric colored QG multiple-description (MD) RDF in the case of two descriptions, can be parametrized via two Lagrangian variables. To establish this result, we use two key ideas. First, we propose a new representation for the MD test channel, and show that the minimum mutual information rate across this channel coincide with the QG MD RDF. Second, we use variational calculus to obtain a spectral domain representation of the test channel's optimal side and central distortion spectra given the source spectral density and the side and central distortion constraints. The distortion spectra are specified via two Lagrangian parameters, which control the trade-off between the side distortion, the central distortion, and the coding rate.We also show that the symmetric colored QG MD RDF can be achieved by noise-shaped predictive coding, dithered quantization, and memoryless entropy coding. In particular, we show that the proposed MD test channel can be materialized by embedding two source prediction loops, one for each description, within a common noise shaping loop whose parameters are explicitly found from the spectral-domain characterization. The source prediction loops exploit the source memory, and thus reduce the coding rate. The noise-shaping loop, controls the trade-off between the side and the central distortions by shaping the quantization noise.
Kochman Yuval
Ostergaard Jan
Zamir Ram
No associations
LandOfFree
Colored Gaussian Multiple Descriptions: Spectral-Domain Characterization and Time-Domain Design does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Colored Gaussian Multiple Descriptions: Spectral-Domain Characterization and Time-Domain Design, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Colored Gaussian Multiple Descriptions: Spectral-Domain Characterization and Time-Domain Design will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-492124