高空通信平台非正交广播与单播复用容量研究

高空平台（High Altitude Platform，HAP）通信以其低成本和广覆盖的优点受到较高的关注，其部署特征有利于多媒体广播的应用。本文引入多HAP广播与单播的功率域非正交复用（Power Domain Non-orthogonal Multiplexing，PD-NOM）方案，将广播信号与单播信号在功率域叠加后实现同时同频传输，能有效克服现有正交时分复用（Orthogonal Time-division Multiplexing，OTDM）方案中广播与单播抢占系统资源的问题。本文分析了PD-NOM方案与OTDM方案的用户单播容量和广播容量，仿真和分析结果表明，在单播容量一致的情况下，采用PD-NOM方案的小区广播平均容量相对OTDM方案有显著提升，在典型的3个HAP覆盖场景下，PD-NOM相对OTDM的广播容量增益可高达150%。

Research on Capacity of High-Altitude Communication Platform with Non-orthogonal Broadcasting and Unicast Multiplexing

High altitude platform (HAP) communication has received high attention due to its low cost and wide coverage advantages, and its deployment characteristics are conducive to the application of multimedia broadcasting. This paper introduces power domain non-orthogonal multiplexing (PD-NOM) scheme into multi-HAP broadcast and unicast scenario. The broadcast signal and the unicast signal are superimposed in the power domain to achieve simultaneous transmission on the same frequency. It can effectively overcome the problem of preempting system resources by broadcast and unicast in the existing orthogonal time-division multiplexing (OTDM) scheme. This paper analyzes the unicast capacity and broadcast capacity of the PD-NOM scheme and the OTDM scheme. The simulation results show that compared with the OTDM scheme, the average broadcast capacity of the cell corresponding to the PD-NOM scheme is higher under all broadcast time slot ratios. With the typical 3 HAPs scenario, the broadcast capacity again of PD-NOM relative to OTDM can be as high as 150%.