Approximating the Gaussian Multiple Description Rate Region Under Symmetric Distortion Constraints

We consider multiple description (MD) coding for the Gaussian source with K descriptions under the symmetric meansquared error (MSE) distortion constraints, and provide an approximate characterization of the rate region. We show that the rate region can be sandwiched between two polytopes, between which the gap can be upper-bounded by constants dependent on the number of descriptions, but independent of the distortion constraints. Underlying this result is an exact characterization of the lossless multilevel diversity source coding problem: a lossless counterpart of the MD problem. This connection provides a polytopic template for the inner and outer bounds to the rate region. In order to establish the outer bound, we generalize Ozarow's technique to introduce a strategic expansion of the original probability space by more than one random variable. For the symmetric rate case with any number of descriptions, we show that the gap between the upper bound and the lower bound for the ...

• Type: Journal
• Year: 2008
• Where: CORR
• Authors: Chao Tian, Soheil Mohajer, Suhas N. Diggavi
• Keywords: CORR 2008, Description, Education, Lossless Multilevel Diversity, Rate Region