  A point-to-point integrated sensing and communication (ISAC) system is
considered where a transmitter conveys a message to a receiver over a discrete
memoryless channel (DMC) and simultaneously estimates the state of the channel
through the backscattered signals of the emitted waveform.
  We derive achievability and converse bounds on the rate-distortion-error
tradeoff in the finite blocklength regime, and also characterize the
second-order rate-distortion-error region for the proposed setup. Numerical
analysis shows that our proposed joint ISAC scheme significantly outperforms
traditional time-sharing based schemes where the available resources are split
between the sensing and communication tasks.
