Transmitting k samples over the Gaussian channel: Energy-distortion tradeoff

We investigate the minimum transmitted energy required to reproduce k source samples with a given fidelity after transmission over a memoryless Gaussian channel. In particular, we analyze the reduction in transmitted energy that accrues thanks to the availability of noiseless feedback. Allowing a nonvanishing excess distortion probability ∈ boosts the asymptotic fundamental limit by a factor of 1-∈, with or without feedback. If feedback is available, achieving guaranteed distortion with finite average energy is possible.