高铁场景下联合天线与IOS单元选择的分布式IOS-SM传输方案

针对高铁场景下封闭车厢带来的高信号穿透损耗导致传输速率下降问题，提出一种分布式智能全表面（intelligent omni-surface,IOS）辅助空间调制（spatial modulation,SM）的传输方案。首先，采用SM技术保证索引信息部分不受穿透损耗的影响；然后，为了减小远距离IOS车窗的高路径损耗和功率损耗，根据最大化接收信噪比原则对分布式IOS遍历选择，激活最佳IOS车窗传输SM调制信息。最后，为了减小缺失直视路径增益对系统容量性能的影响，基于功率损耗模型，采用天线移除原则和排序选择方式，对接收天线和IOS单元进行动态选择激活。仿真结果表明，相比于传统中继转发和可重构智能超表面-空间调制（reconfigurable intelligence surface-SM,RIS-SM）方案，所提方案更适合高铁通信场景。并且在功率损耗模型下，联合天线与IOS单元选择的分布式IOS-SM方案仍能够保证系统高性能传输。

Distributed IOS-SM transmission scheme with joint antenna and IOS unit selection for high-speed railway scenario

A distributed intelligent omni-surface (IOS) -assisted spatial modulation (SM) transmission scheme was proposed to address the problem of transmission rate degradation caused by the high signal penetration loss in closed carriages in the high-speed railway scenarios.Firstly, SM technology was utilized to ensure that the indexed information section was not affected by penetration loss.Then, to reduce the high path loss and power loss of the long-range IOS windows, the distributed IOS was selected by traversal algorithm according to the principle of maximizing the received signal-to-noise ratio, and the best IOS window was activated to transmit the SM modulated information.Finally, to reduce the impact of the missing direct view path gain on the overall system performance, the antenna removal principle and the sequential selection method were used to dynamically and selectively activate the receiving antenna and IOS unit under the power consumption model.The simulation results show that the proposed scheme is more suitable for the high-speed railway wireless communication scenario than the conventional relay-forwarding and reconfigurable intelligence surface -SM (RIS-SM) schemes.And with the power loss model, the distributed IOS-SM scheme chosen by the combined antenna and IOS unit is still able to guarantee high performance transmission of the system.