Multiple Description (MD) Coding is a source coding technique for information transmission over unreliable networks. In MD coding, the coder generates several different descriptions of the same signal and the decoder can produce a useful reconstruction of the source with any received subset of these descriptions. Unlike multiresolution or layered source coding, there is no hierarchy of descriptions; thus, MD coding is suitable for erasure channels or packet networks without priority provisions.
We have mostly focused on the problem of designing critically subsampled and oversampled filter banks for MD coding. In the case of two-channels filter banks and stationary Gaussian input sources, we found explicit formulae for the optimal frequency responses of the analysis and synthesis filters. In the more general case of M channels oversampled filter banks, we proved that filter banks implementing tight frames usually attains optimal performance.
Current and Future Research
There is a growing interest in the so called ad-hoc networks, that is in networks that rapidly change their structure in time. We are interested in designing MD coders which are particularly suited for this kind of networks and in analyzing their performance.
Vivek K. Goyal (Bell Labs – Murray Hill, NJ, USA), Jelena Kovacevic (Bell Labs – Murray Hill, NJ, USA), Sergio Servetto, Martin Vetterli.
September 1998 – October 2002.
SNF project numbers: 21-52439.97, 20-61493.
P.L. Dragotti, S.D. Servetto and M. Vetterli, Optimal Filter Banks for Multiple Description Coding: Analysis and Synthesis, IEEE Transactions on Information Theory, Vol. 48, Nr. 7, pp. 2036-2052, 2002.
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