  In a growing number of applications, there is a need to digitize signals
whose spectral characteristics are challenging for traditional
Analog-to-Digital Converters (ADCs). Examples, among others, include systems
where the ADC must acquire at once a very wide but sparsely and dynamically
occupied bandwidth supporting diverse services, as well as systems where the
signal of interest is subject to strong narrowband co-channel interference. In
such scenarios, the resolution requirements can be prohibitively high. As an
alternative, the recently proposed modulo-ADC architecture can in principle
require dramatically fewer bits in the conversation to obtain the target
fidelity, but requires that information about the spectrum be known and
explicitly taken into account by the analog and digital processing in the
converter, which is frequently impractical. To address this limitation, we
develop a blind version of the architecture that requires no such knowledge in
the converter, without sacrificing performance. In particular, it features an
automatic modulo-level adjustment and a fully adaptive modulo unwrapping
mechanism, allowing it to asymptotically match the characteristics of the
unknown input signal. In addition to detailed analysis, simulations demonstrate
the attractive performance characteristics in representative settings.
