We consider the progressive transmission of a lossy source across a power c
onstrained Gaussian channel using binary phase-shift keying modulation. Und
er the theoretical assumptions of infinite bandwidth, arbitrarily complex c
hannel coding, and lossless transmission, we derive the optimal channel cod
e rate and the optimal energy allocation per transmitted bit. Under the pra
ctical assumptions of a low complexity class of algebraic channel codes and
progressive image coding, we numerically optimize the choice of channel co
de rate and the energy, per bit allocation. This model provides an addition
al degree of freedom with respect to previously proposed schemes, and can a
chieve a higher performance for sources such as images. It also allows one
to control bandwidth expansion or reduction.