Precoding for Satellite Communications: Why, How and What Next?

Precoding has stood out as a promising multi-user multi-antenna 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 while improving spectral efficiency. Satellite systems offer multitude of system and service configurations, resulting in different precoder design methodologies. This letter explores the motivation for the introduction of precoding, offers an insight to their theoretical development in diverse scenarios and presents some avenues for future development.