  Millimeter-wave (mmWave) massive multi-user multiple-input multiple-output
(MU-MIMO) promises unprecedented data rates for next-generation wireless
systems. To be practically viable, mmWave massive MU-MIMO basestations (BSs)
must rely on low-resolution data converters which leaves them vulnerable to
jammer interference. This paper proposes beam-slicing, a method that mitigates
the impact of a permanently transmitting jammer during uplink transmission for
BSs equipped with low-resolution analog-to-digital converters (ADCs).
Beam-slicing is a localized analog spatial transform that focuses the jammer
energy onto few ADCs, so that the transmitted data can be recovered based on
the outputs of the interference-free ADCs. We demonstrate the efficacy of
beam-slicing in combination with two digital jammer-mitigating data detectors:
SNIPS and CHOPS. Soft-Nulling of Interferers with Partitions in Space (SNIPS)
combines beam-slicing with a soft-nulling data detector that exploits knowledge
of the ADC contamination; projeCtion onto ortHOgonal complement with Partitions
in Space (CHOPS) combines beam-slicing with a linear projection that removes
all signal components co-linear to an estimate of the jammer channel. Our
results show that beam-slicing enables SNIPS and CHOPS to successfully serve
65% of the user equipments (UEs) for scenarios in which their antenna-domain
counterparts that lack beam-slicing are only able to serve 2% of the UEs.
