A Tight Bound on the Performance of a Minimal-Delay Joint Source-Channel Coding Scheme

An analog source is to be transmitted across a Gaussian channel in more than one channel use per source symbol. This paper derives a lower bound on the asymptotic mean squared error for a strategy that consists of repeatedly quantizing the source, transmitting the quantizer outputs in the first channel uses, and sending the remaining quantization error uncoded in the last channel use. The bound coincides with the performance achieved by a suboptimal decoder studied by the authors in a previous paper, thereby establishing that the bound is tight.Comment: 5 pages, submitted to IEEE International Symposium on Information Theory (ISIT) 201

Asymptotically Optimal Joint Source-Channel Coding with Minimal Delay

We present and analyze a joint source-channel coding strategy for the transmission of a Gaussian source across a Gaussian channel in n channel uses per source symbol. Among all such strategies, our scheme has the following properties: i) the resulting mean-squared error scales optimally with the signal-to-noise ratio, and ii) the scheme is easy to implement and the incurred delay is minimal, in the sense that a single source symbol is encoded at a time.Comment: 5 pages, 1 figure, final version accepted at IEEE Globecom 2009 (Communication Theory Symposium