Technical Program

Paper Detail

Paper Title A Lower Bound on the Expected Distortion of Joint Source-Channel Coding
Paper IdentifierTU4.R6.4
Authors Yuval Kochman, Or Ordentlich, Hebrew University of Jerusalem, Israel; Yury Polyanskiy, Massachusetts Institute of Technology, United States
Session Joint Source Channel Coding
Location Sorbonne, Level 5
Session Time Tuesday, 09 July, 16:40 - 18:00
Presentation Time Tuesday, 09 July, 17:40 - 18:00
Manuscript  Click here to download the manuscript
Abstract We consider the classic joint source-channel coding problem of transmitting a memoryless source over a memoryless channel. The focus of this work is on the rate of convergence of the smallest attainable expected distortion to its asymptotic value, as a function of blocklength $n$. Our main result is that in general the convergence rate is not faster than $n^{-1/2}$. In particular, we show that for the problem of transmitting i.i.d uniform bits over a binary symmetric channels with Hamming distortion, the smallest attainable distortion (bit error rate) is at least $\Omega(n^{-1/2})$ above the asymptotic value, if the ``bandwidth expansion ratio'' is above $1$.