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Minimum Expected Distortion in Gaussian Source Coding with Uncertain Side Information
| Content Provider | CiteSeerX |
|---|---|
| Author | Ng, Chris T. K. Shitz, Shlomo Shamai Goldsmith, Andrea J. Tian, Chao |
| Abstract | Abstract — We consider a layered approach to source coding with side information received over an uncertain channel that minimizes expected distortion. Specifically, we assume a Gaussian source encoder whereby the decoder receives a compressed version of the symbol at a given rate, as well as an uncompressed version over a separate side-information channel with slow fading and noise. The decoder knows the realization of the slow fading but the encoder knows only its distribution. We consider a layered encoding strategy with a base layer describing the source assuming worst-case fading on the side-information channel, and subsequent layers describing the source under better fading conditions. Optimization of the layering scheme utilizes the Heegard-Berger rate-distortion function that describes the rate required to meet a different distortion constraint for each fading state. When the side-information channel has two discrete fading states, we obtain closed-form expressions for the optimal rate allocation between the fading states and the resulting minimum expected distortion. For multiple fading states, the minimum expected distortion is formulated as the solution of a convex optimization problem. Under discretized Rayleigh fading, we show that the optimal rate allocation puts almost all rate into the base layer associated with the worst-case fading. This implies that uncertain side information yields little performance benefit over no side information. Moreover, as the source coding rate increases, the benefit of uncertain side-information decreases. I. |
| File Format | |
| Access Restriction | Open |
| Subject Keyword | Layering Scheme Slow Fading Side-information Channel Discretized Rayleigh Fading Optimal Rate Allocation Compressed Version Convex Optimization Problem Layered Approach Closed-form Expression Base Layer Uncertain Channel Worst-case Fading Uncertain Side-information Decrease Subsequent Layer Heegard-berger Rate-distortion Function Layered Encoding Strategy Fading State Gaussian Source Encoder Side Information Gaussian Source Coding Different Distortion Constraint Minimum Expected Distortion Uncompressed Version Uncertain Side Information Rate Increase Multiple Fading State Separate Side-information Channel Fading Condition |
| Content Type | Text |
