  We consider the rates achievable by a user in a multibeam satellite system
for unicast applications, and propose alternatives to the conventional
single-user symbol-by-symbol detection applied at user terminals. Single-user
detection is known to suffer from strong degradation when the terminal is
located near the edge of the coverage area of a beam, and when aggressive
frequency reuse is adopted. For this reason, we consider multiuser detection,
and take into account the strongest interfering signal. We also analyze two
additional transmission strategies requiring modifications at medium access
control layer. We describe an information-theoretic framework to compare the
different strategies by computing the information rate of the user in the
reference beam. Furthermore, we analyze the performance of coded schemes that
could approach the information-theoretic limits. We show that classical codes
from the DVB-S2(X) standard are not suitable when multiuser detection is
adopted, and we propose two ways to improve the performance, based on the
redesign of the code and of the bit mapping.
