An Asymmetric Difference Multiple Description Gaussian Noise Channel

Ozarow's test channel for the quadratic Gaussian (QG) multiple description (MD) problem consists of two correlated AWGN channels. It is known that simply replacing the AWGN channels by quantizers with equivalent statistical properties as the channels, will generally not lead to a rate-distortion optimal realization of the MD rate-distortion function. We have previously proposed a symmetric two-channel model for the QG MD problem for the case, where the two noise terms have equal variances. We show in this paper, that by replacing the AWGN channels of this model by quantizers that are statistical equivalent to the channels, will under high-resolution assumption be rate-distortion optimal. We furthermore extend this symmetric two-channel model to the asymmetric case, and provide a simple suboptimal implementation of the channel based on scalar quantizers. Simulations are provided to show the performance of the proposed implementation.