This paper considers the zero-delay transmission of a
Gaussian source over an additive white Gaussian noise (AWGN)
channel with a one-bit analog-to-digital converter (ADC) front
end. The optimization of the encoder and decoder is tackled
under both the mean squared error (MSE) distortion and the
outage distortion criteria with an average power constraint. For
MSE distortion, the optimal transceiver is identified over the
space of symmetric encoders. This result demonstrates that the
linear encoder, which is optimal with a full-precision front end,
approaches optimality only in the low signal-to-noise ratio (SNR)
regime; while, digital transmission is optimal in the high SNR
regime. For the outage distortion criterion, the structure of the
optimal encoder and decoder are obtained. In particular, it is
shown that the encoder mapping is piecewise constant and can
take only two opposite values when it is non-zero.
Index Terms-Joint source channel coding, zero-delay transmis-
sion, average distortion, outage distortion, one-bit ADC.