Variable Rate Lossy Source-Channel Coding over Channels with Feedback
Information Theory
Summary
The authors developed a new method to send and compress data together over noisy communication channels that have bursts of errors and feedback to the sender. Their method uses multiple steps where it smartly decides how many bits to use at each step by looking at information coming back from the channel. They tested their method on a complex noise model and found it works better than older fixed-bit methods, improving the quality of the received signal by up to 4.5 dB. This approach adapts to changing noise conditions to reduce errors more effectively.
Authors
Timothy Liu, Fady Alajaji, Tamás Linder
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.