  Energy efficiency (EE) problem has become an important and major issue in
satellite communications. In this paper, we study the beamforming design
strategy to maximize the EE of rate-splitting multiple access (RSMA) for the
multibeam satellite communications by considering imperfect channel state
information at the transmitter (CSIT). We propose an expectation-based robust
beamforming algorithm against the imperfect CSIT scenario. By combining the
successive convex approximation (SCA) with the penalty function transformation,
the nonconvex EE maximization problem can be solved in an iterative manner. The
simulation results demonstrate the effectiveness and superiority of RSMA over
traditional space division multiple access (SDMA). Moreover, our proposed
beamforming algorithm can achieve better EE performance than the conventional
beamforming algorithm.
