New Results on Multiple Descriptions in the Wyner-Ziv Setting
Some new results of multiple descriptions in the Wyner-Ziv setting (MDWZ) are presented. MDWZ uses two pieces of side information (SI) for two different side decoders. Both SI are available to the central decoder, but none to the encoder. The complete achievable region for a quadratic Gaussian MDWZ system is derived. This result is an extension of Ozarow's result on multiple descriptions of a Gaussian source without SI and Diggavi-Vaishampayan's result on common SI. It is shown that a refinement layer for the central decoder is indispensable if the central distortion is sufficiently small. The tight rate distortion region is also given if one of the side decoders is required to perfectly reconstruct a deterministic function of the source.