  This letter studies the mechanism of uplink multiple access and jamming
suppression in an OTFS system. Specifically, we propose a novel resource
hopping mechanism for orthogonal time frequency space (OTFS) systems with delay
or Doppler partitioned sparse code multiple access (SCMA) to mitigate the
effect of jamming in controlled multiuser uplink. We analyze the non-uniform
impact of classic jamming signals such as narrowband interference (NBI) and
periodic impulse noise (PIN) in delay-Doppler (DD) domain on OTFS systems.
Leveraging turbo equalization, our proposed hopping method demonstrates
consistent BER performance improvement under jamming over conventional
OTFS-SCMA systems compared to static resource allocation schemes.
