广域空基宽带无线通信理论与空地多波束高通量传输方法

The space-air-ground integrated networks are expected to help the development of the sixth generation mobile communications. The Internet of Space (IoS) with dense Low Earth Orbit (LEO) satellites is the hotspot of contemporary research. However, a series of problems such as orbit, spectrum, cost, operation, maintenance and space trash caused by thousands of dense LEO satellites in the future cannot be avoided. Therefore, this project proposes an idea of air-based wireless communication based on civil aviation. Most LEO satellites will be replaced as communications access platforms by the aircrafts on the increasingly dense aircraft lines. To make full use of the horizon aircrafts to form wide-area air-based broadband wireless communication networks. The major research works of this project are as follows: 1. The theory of 3-dimension air-and-earth wireless transmission channel capacity and the analysis of angular domain spectral efficiency. 2. The research on air-based network geometry and service coverage characteristics. The project proposes the coverage and the scheme of joint compensatory coverage for blind area from space and time two aspects, and explores the networking approaches of the dynamic topology oriented integration of space-air-earth. 3. Aiming at the aircraft conformal irregular antenna arrays, the clustered high gain with staring multi-beamforming techniques will be studied. 4. In order to meet the requirements of high-throughput transmission, the air-earth Massive MIMO transmission mechanism is studied. Higher energy efficiency performance and anti-overload ability are obtained by optimizing selective multi-subarrays. The main feature of this project is that the unware massive civil aircrafts take the place of the traditional idea of priority to dense LEO satellites. It has the great innovation value for the development of the space-air-earth networks.

空天地一体化网络有望助力第六代移动通信发展，以密集低轨道（LEO）卫星组成空间互联网（IoS）是当前热点，然而未来数以万计的密集LEO卫星带来的轨道、频谱、成本、运维和太空垃圾等大量问题无法回避。本项目提出基于民航的空基无线通信构想，以越来越密集航线上的飞机替代大部分LEO卫星作为通信接入平台，充分利用视距飞机形成广域空基宽带无线通信网络。项目拟开展研究内容如下：1. 空地无线三维信道容量理论与角域频谱效率分析；2. 研究空基网络几何与业务覆盖特性，给出空时覆盖率和联合补盲方案，探索面向动态拓扑的天空地一体化组网方法；3. 针对飞机共形不规则阵列，研究分簇高增益凝视多波束形成技术；4. 面向高通量传输需求，研究空地Massive MIMO传输机理，通过优化选择性多子阵，实现高能效和抗过载。本项目最大特色是改变依赖LEO的传统思路，代之以无感捎带的民航飞机，对空天地网络发展具有重要创新价值。

空天地一体化网络有望助力第六代移动通信发展。目前，空天地一体化网络主要以低轨卫星作为天基平台主体、并联合如无人机等空基平台为地面用户提供补充服务。然而，未来数以万计的密集低轨卫星带来的轨道、频谱、成本、运维和太空垃圾等大量问题无法回避。同时，无人机能耗与载荷受限、需要频繁发射等问题，也限制了其成为常态化广域覆盖平台。因此，本项目提出基于民航的空基无线通信构想，从多维角度详细论证密集航线上的飞机作为通信接入平台的可行性，充分利用视距飞机形成广域空基宽带无线通信网络，为我国空天地一体化网络研究提出重要的理论基础与崭新的发展思路。.本项目针对空基宽带无线通信网络容量理论与谱效、空基网络通信覆盖与组网机理、不规则阵列天线动态分簇多波束形成及凝视方法、空基宽带通信网的高通量高能效传输理论与方法分别展开了理论分析与性能验证。本项目推导了空天地融合网络中每层的遍历容量和覆盖概率闭合表达式，证明空基宽带无线通信网络采用多平台协作策略的遍历容量是原天地融合网络的1.56倍；设计了双层空天网络联合覆盖方案与网络资源按需分配的优化方法，提出了用户与业务联合优先级与网络效率的概念，证明在相同通信能力的卫星网络覆盖下，民航飞机网络的引入能够减少星座中88.9%的卫星，以及当网络出现拥塞时，应用用户更新机制可以达到最优的网络效益；提出了基于多普勒频移预测运动轨迹的凝视波束方案，证明凝视波束形成技术会带来的波束指向误差不超过0.5°；提出一种对干扰和噪声抑制的射频预编码与空基大规模天线双向中继系统分析方案，证明当发射功率恒定且各个节点都配置大规模天线时，系统的渐近频谱效率趋近于无穷。.本项目研究了空地链路信道容量极限理论、空基阵列天线按需动态最优分簇、广域空基海量信息无缝传输的科学问题，从覆盖、组网和传输等多方面论证了飞机网络对天地融合网络的有效支持，具有潜在的颠覆性体系价值、深入的前瞻性学术价值以及鲜明的可行性应用价值。