卫星物联网容量增强的波束优化设计技术研究  

Research on Beam Optimization Design Technology for Capacity Enhancement of Satellite Internet of Things

作　　者：刘子威 徐圆圆 边东明 张更新 LIU Ziwei;XU Yuanyuan;BIAN Dongming;ZHANG Gengxin(School of Communications and Information Engineering,Nanjing University of Posts and Telecommunications,Nanjing 210003,China;College of Communications Engineering,Army Engineering University of PLA,Nanjing 210007,China)

机构地区：[1]南京邮电大学通信与信息工程学院,南京210003 [2]陆军工程大学通信工程学院,南京210007

出　　处：《电子与信息学报》2025年第1期93-101,共9页Journal of Electronics & Information Technology

基　　金：国家自然科学基金(61971440,62271266,U21A20450);江苏省自然科学基金重大项目(BK20192002)。

摘　　要：卫星物联网终端低功耗、轻控制的设计需求导致系统采用常规随机接入协议时易发生大量碰撞,难以满足系统吞吐量要求。现有容碰撞随机接入技术依赖功率控制、波形积累的方式,在实际中难以实现。该文分析了功率域碰撞分离所需条件,提出面向功率域信号分离的辅助波束设计方案,在常规接收波束外增设辅助接收波束,通过优化辅助波束增益构造接收信号信噪比差异,支撑碰撞信号分离。仿真表明,所提方案能够显著提升随机接入的吞吐量。Objective Under the hundreds of kilometers of transmission distance in low-orbit satellite communication,both power consumption and latency are significantly higher than that in ground-based networks.Additionally,many data collection services exhibit short burst characteristics.Conventional resource reservation-based access methods have extremely low resource utilization,whereas dynamic application-based access methods incur large signaling overhead and fail to meet the latency and power consumption requirements for satellite Internet of Things(IoT).Random access technology,which involves competition for resources,can better accommodate the short burst data packet services typical of satellite IoT.However,as the load increases,data packet collisions at satellite access points lead to a sharp decline in actual throughput under medium and high loads.In terrestrial wireless networks,technologies such as near-far effect management and power control are commonly employed to create differences in packet reception power.However,due to the large number of terminals covered and the long distance between the satellite and the Earth,these techniques are unsuitable for satellite IoT,preventing the establishment of an adequate carrier-to-noise ratio.Developing separation conditions suitable for satellite IoT access scenarios is a key research focus.Considering the future development of spaceborne digital phased array technology,this paper leverages the data-driven beamforming capability of the on-board phased array and introduces the concept of spatial auxiliary channels.By employing a sum-and-difference beam design method,it expands the dimensions for separating collision signals beyond the time,frequency,and energy domains.This approach imposes no additional processing burdens on the terminal and aligns with the low power consumption and minimal control design principles for satellite IoT.Methods To address packet collision issues in hotspot areas of satellite IoT services,this study extends the conventional time-slot ALOHA

关 键 词：卫星物联网 随机接入 信号分离 波束形成 

分 类 号：TN927.2[电子电信—通信与信息系统]