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.

翻译：能效问题已成为卫星通信中的关键议题。本文针对多波束卫星通信系统，在考虑发射端信道状态信息非理想的情况下，研究基于速率分割多址接入技术的波束赋形设计策略以最大化系统能效。针对非理想信道状态信息场景，提出一种基于期望的鲁棒波束赋形算法。通过将逐次凸近似与罚函数变换相结合，可迭代求解非凸的能效最大化问题。仿真结果表明，速率分割多址接入技术相较于传统空分多址接入具有更优的性能表现。此外，所提波束赋形算法相较于传统方法能获得更好的能效性能。