  The present paper is devoted to investigation of the classical capacity of
infinite-dimensional quantum measurement channels. A number of usable
conditions are introduced that enable us to apply previously obtained general
results to specific models, in particular, to the multi-mode bosonic Gaussian
measurement channels. An explicit formula for the classical capacity of the
Gaussian measurement channel is obtained in this paper without assuming the
global gauge symmetry, solely under certain "threshold condition". The result
is illustrated by the capacity computation for one-mode squeezed-noise
heterodyne measurement channel.
