  The one- and two-boson momentum spectra are derived in the quantum
local-equilibrium canonical ensemble of noninteracting bosons with a fixed
particle number constraint. We define the canonical ensemble as a subensemble
of events associated with the grand-canonical ensemble. Applying simple
hydro-inspired parametrization with parameter values that correspond roughly to
the values at the system's breakup in $p+p$ collisions at the LHC energies, we
compare our findings with the treatment which is based on the grand-canonical
ensembles where mean particle numbers coincide with fixed particle numbers in
the canonical ensembles. We observe a significantly greater sensitivity of the
two-particle momentum correlation functions to fixed multiplicity constraint
compared to one-particle momentum spectra. The results of our analysis may be
useful for interpretation of multiplicity-dependent measurements of $p+p$
collision events.
