  Precise characterization of detector time resolution is of crucial importance
for next-generation cryogenic-bolometer experiments searching for neutrinoless
double-beta decay, such as CUPID, in order to reject background due to pile-up
of two-neutrino double-beta decay events. In this paper, we describe a
technique developed to study the pile-up rejection capability of cryogenic
bolometers. Our approach, which consists of producing controlled pile-up events
with a programmable waveform generator, has the benefit that we can reliably
and reproducibly control the time separation and relative energy of the
individual components of the generated pile-up events. The resulting data allow
us to optimize and benchmark analysis strategies to discriminate between
individual and pile-up pulses. We describe a test of this technique performed
with a small array of detectors at the Laboratori Nazionali del Gran Sasso, in
Italy; we obtain a 90% rejection efficiency against pulser-generated pile-up
events with rise time of ~15ms down to time separation between the individual
events of about 2ms.
