Precoding Design for Energy Efficiency of Multibeam Satellite Communications

Instead of merely improving the spectral efficiency (SE), improving the energy efficiency (EE) is another important concern for multibeam satellite systems, due to the power constraint of satellites. However, so far there has been no detailed work on the precoding design concerning the EE for multibeam satellite. In this work, the EE maximization problem is investigated for multibeam satellite systems under the total power constraint as well as the quality of service (QoS) constraints. Precoding design algorithms based on zero forcing (ZF) and sequential convex approximation (SCA) are presented respectively. In particular, these algorithms are verified by the real measured channel data of multibeam satellite systems. Numerical results show that the precoding algorithm based on SCA outperforms that based on ZF. It is also implied that the EE cannot be always improved by solely increasing the power of the satellite, while reducing the satellite operation power is an effective way for the EE improvement.