Optical mobile communication (OMC) provides a hopeful vision to handle with wireless communication scenarios where multiple mobile users are involved. In previous work, achievable rate analysis for broadcast OMC system with coherent transmission and detection is given. Although it was shown that OMC has superior performance compared with conventional schemes, coherent processing imposes strong challenges on the hardware design. In practice, intensity modulation (IM) and direct detection (DD) is more implementation-friendly. However, the result in coherent processing cannot be migrated to IM/DD scenario since IM imposes new constraints on the signal model, making it more challenging to evaluate the rate performance. Motivated by this, in this paper, we investigate the rate performance of broadcast OMC in IM/DD mode with user mobility. The aim of this work is to reveal the potential gain of OMC with IM/DD over some benchmark schemes. By assuming dense pulse amplitude modulation (PAM), the rate is assessed through mutual information with proposed power allocation algorithm. Through simulation results, it is found that OMC outperforms conventional free space optical (FSO) communication in time division mode at high SNR region with not-so-large number of users.

中文翻译：

---

具有用户移动性的强度调制广播光移动通信系统的速率分析

光移动通信 (OMC) 为处理涉及多个移动用户的无线通信场景提供了充满希望的愿景。在前人的工作中，给出了具有相干传输和检测的广播OMC系统的可实现速率分析。尽管表明 OMC 与传统方案相比具有优越的性能，但相干处理对硬件设计提出了很大的挑战。在实践中，强度调制 (IM) 和直接检测 (DD) 更易于实现。然而，相干处理的结果不能迁移到 IM/DD 场景，因为 IM 对信号模型施加了新的约束，使得评估速率性能更具挑战性。受此启发，在本文中，我们研究了具有用户移动性的 IM/DD 模式下广播 OMC 的速率性能。这项工作的目的是揭示 OMC 与 IM/DD 相比某些基准方案的潜在收益。通过假设密集脉冲幅度调制（PAM），速率通过互信息与建议的功率分配算法进行评估。通过仿真结果，发现 OMC 在时分模式下在高 SNR 区域和用户数量不多的情况下优于传统的自由空间光 (FSO) 通信。