Structure Theorems for Real-Time Variable Rate Coding With and Without Side Information

The output of a discrete Markov source is to be encoded instantaneously by a variable-rate encoder and decoded by a finite-state decoder. Our performance measure is a linear combination of the distortion and the instantaneous rate. Structure theorems, pertaining to the encoder and next-state functions, are derived for every given finite-state decoder, which can have access to side information.