  Precoding has stood out as a promising multi-user transmission technique to
meet the emerging throughput demand of satellite communication systems while
awaiting the technological maturity for exploiting higher bands. Precoding
enables the reduction of interference among co-channel beams through spatial
processing while promoting aggressive frequency reuse and improving spectral
efficiency. Satellite systems offer multitude of system and service
configurations, resulting in different precoder design methodologies. This
article explores the motivation for the introduction of precoding, offers an
insight to their theoretical development in a diverse scenarios and presents
some avenues for future development.
