TRADEOFF BETWEEN SOURCE AND CHANNEL CODING

A fundamental problem in the transmission of analog information across a noisy discrete channel is the choice of channel code rate that opti mally allocates the available transmission rate between lossy source c oding and block channel coding, We establish tight bounds on the chann el code rate that minimizes the average distortion of a vector quantiz er cascaded with a channel coder and a binary-symmetric channel, Analy tic expressions are derived in two cases of interest: small bit-error probability and arbitrary source vector dimension; arbitrary bit-error probability and large source vector dimension, We demonstrate that th e optimal channel code rate is often substantially smaller than the ch annel capacity, and obtain a noisy-channel version of the Zador high-r esolution distortion formula.