  With the expanding demand for high data rates and extensive coverage, high
throughput satellite (HTS) communication systems are emerging as a key
technology for future communication generations. However, current frequency
bands are increasingly congested. Until the maturity of communication systems
to operate on higher bands, the solution is to exploit the already existing
frequency bands more efficiently. In this context, precoding emerges as one of
the prolific approaches to increasing spectral efficiency. This survey presents
an overview and a classification of the recent precoding techniques for HTS
communication systems from two main perspectives: 1) a problem formulation
perspective and 2) a system design perspective. From a problem formulation
point of view, precoding techniques are classified according to the precoding
objective, group, and level. From a system design standpoint, precoding is
categorized based on the system architecture, the precoding implementation, and
the type of the provided service. Further, practical system impairments are
discussed, and robust precoding techniques are presented. Finally, future
trends in precoding for satellites are addressed to spur further research.
