A novel coding scheme for symmetric multiple description coding

We propose a novel coding scheme for multiple description coding with K descriptions, with symmetric rate and symmetric distortion constraints. In this new coding scheme, channel codes are introduced on top of some carefully chosen source coding component. The channel coding component for k = 3 is akin to the network coding idea. We first show that for the quadratic Gaussian source, adding a simple channel coding component is able to achieve rate- distortion point outside the achievable region based on (n, k) source-channel erasure codes (SCEC), previously proposed by Puri et al, when Gaussian codebook is assumed to be optimal for that scheme. The channel coding component and (n, k) SCEC can be strategically combined, and for the special case of quadratic Gaussian three description case where any two of them are rate-distortion optimal jointly, the resulting scheme can achieve performance better than a direct time sharing between the new operating point and the (n, k) SCEC-based scheme. Moreover, this combination can be generalized naturally, which leads to a new coding scheme for the general if-description problem.