In recent years, the rapid evolution of satellite communications play a pivotal role in addressing the ever-increasing demand for global connectivity, among which the Low Earth Orbit (LEO) satellites attract a great amount of attention due to their low latency and high data throughput capabilities. Based on this, we explore spatial modulation (SM) and space shift keying (SSK) designs as pivotal techniques to enhance spectral efficiency (SE) and bit-error rate (BER) performance in the LEO satellite-assisted multiple-input multiple-output (MIMO) systems. The various performance analysis of these designs are presented in this paper, revealing insightful findings and conclusions through analytical methods and Monte Carlo simulations with perfect and imperfect channel state information (CSI) estimation. The results provide a comprehensive analysis of the merits and trade-offs associated with the investigated schemes, particularly in terms of BER, computational complexity, and SE. This analysis underscores the potential of both schemes as viable candidates for future 6G LEO satellite-assisted wireless communication systems.

翻译：近年来，卫星通信的快速发展在满足日益增长的全球连接需求方面发挥着关键作用，其中低地球轨道（LEO）卫星因其低延迟和高数据吞吐能力而备受关注。基于此，我们探索了空间调制（SM）与空间移位键控（SSK）设计，将其作为提升LEO卫星辅助多输入多输出（MIMO）系统频谱效率（SE）与误码率（BER）性能的关键技术。本文展示了这些设计的多种性能分析，通过解析方法与蒙特卡洛仿真，在完美与非完美信道状态信息（CSI）估计条件下，揭示了具有深刻见解的发现与结论。研究结果对所考察方案的优点与权衡进行了全面分析，特别是在误码率、计算复杂度和频谱效率方面。该分析强调了这两种方案作为未来6G LEO卫星辅助无线通信系统可行候选技术的潜力。