  Rate-distortion formulation is the information-theoretic approach to the
study of signal encoding systems. Since a more general approach to model the
nonstationarity exhibited by real-world signals is to use appropriately fitted
time varying autoregressive (TVAR) models, we have investigated the
rate-distortion function for the class of time varying nonstationary signals.
In this study, we present formulations of the rate-distortion function for the
Gaussian TVAR processes. The rate-distortion function can serve as an
information-theoretic bound on the performance achievable by source encoding
techniques when the processing signal is represented exclusively by a Gaussian
TVAR model.
