  In this paper, we study the end-to-end distortion/delay tradeoff for a
analogue source transmitted over a fading channel. The analogue source is
quantized and stored in a buffer until it is transmitted. There are two extreme
cases as far as buffer delay is concerned: no delay and infinite delay. We
observe that there is a significant power gain by introducing a buffer delay.
Our goal is to investigate the situation between these two extremes. Using
recently proposed \emph{effective capacity} concept, we derive a closed-form
formula for this tradeoff. For SISO case, an asymptotically tight upper bound
for our distortion-delay curve is derived, which approaches to the infinite
delay lower bound as $\mathcal{D}_\infty \exp(\frac{C}{\tau_n})$, with $\tau_n$
is the normalized delay, $C$ is a constant. For more general MIMO channel, we
computed the distortion SNR exponent -- the exponential decay rate of the
expected distortion in the high SNR regime. Numerical results demonstrate that
introduction of a small amount delay can save significant transmission power.
