On separation of source and channel coding in the finite block length regime

Abstract

This paper investigates the validity of Shannon's separation theorem in the finite block length regime. Under optimal tradeoffs between source rate and channel block error probability obtained from finite block length analysis, noisy channel quantizers based on joint source-channel coding principles are shown to outperform the separate quantizer designed via Lloyd-Max in terms of end-to-end distortion. Numerical results for the scalar case under the binary symmetric channel and discreteinput memoryless channel demonstrate that the separation of source and channel coding no longer holds in the finite block length regime, but the advantages of joint designs may be large or small depending on the system configuration.Index Terms-joint source-channel coding, finite block length regime, lossy source coding, end-to-end distortion.

Designing Optimal Multiresolution Quantizers with Error Detecting Codes

“…s=1 p e {r = e 1 |r, s} , 1 Note that since the coded broadcast channel is fixed, CRC is considered here to be at the application layer.…”

“…For the wireless channel, JSCC is desirable since Shannon's separation theorem does not apply for non-zero channel error probabilities caused by operation in the finite block length regime [1].…”