Variable Rate Lossy Source-Channel Coding over Channels with Feedback

2026-07-17

AI Summary

This work proposes a variable-rate lossy joint source-channel coding scheme for burst-noise channels with noiseless feedback. By leveraging channel outputs obtained via feedback, the method dynamically allocates bits according to the current channel state through multistage residual vector quantization combined with a greedy bit allocation algorithm. The approach generalizes conventional fixed-rate coding into an adaptive variable-rate framework and models the bursty noise using an M-th order Markov process along with a Pólya contagion channel to capture noise correlation. Experimental results demonstrate that the proposed scheme consistently outperforms fixed-rate baselines across varying bit error rates and levels of noise correlation, achieving up to 4.5 dB signal-to-noise ratio gain and significantly enhancing both adaptability and overall coding performance.

Abstract

A variable-rate lossy joint source-channel coding scheme for burst-noise communication channels with noiseless feedback is introduced. The scheme comprises a multi-stage channel optimized vector quantization system that dynamically allocates bits via a greedy algorithm among the variable-rate residual quantizers at each stage, based on the channel output sequence received at the encoder through the feedback link, thereby generalizing a prior fixed-rate scheme. Simulations over an $M$-th order Markov noise Polya contagion channel demonstrate that the proposed variable-rate scheme consistently outperforms the fixed-rate scheme, regardless of the channel bit error rate and noise correlation, achieving signal-to-noise ratio gains of up to about 4.5 dB.

Problem

• variable-rate coding
• lossy source-channel coding
• burst-noise channels
• noiseless feedback
• vector quantization

Innovation

• variable-rate coding
• joint source-channel coding
• vector quantization
• feedback channel
• burst-noise channel