SpecEES: A spectrally-dense 650-GHz photonic wireless backhaul via secure network coding

在过去十年中，由于移动设备、多媒体服务和数据需求的不断增加，无线通信和网络在数据速率和流量方面经历了指数级增长。因此，即使采用先进的频谱高效调制格式和空间多样化的多输入多输出（MIMO）技术，60 ghz以下的电磁频谱也变得极其拥挤。目前，300 GHz和850 GHz之间的亚毫米波（sub-mm-Wave）电磁频谱大部分未分配，为更有效地利用提供了独特的机会。这将避免进一步拥挤目前大量使用的频谱，并显着将数据速率提高到数十Gb/s。该项目旨在展示这样一个全新的平台，实现具有嵌入式安全性的频谱效率和节能无线通信。由于大气固有的衰减，亚毫米波通信距离被限制在50米以内。因此，该项目提出了亚毫米波点对点链路的网络配置，以实现更长距离和更大区域的安全空间覆盖。与传统无线网络相比，亚毫米波链路有两个明显的区别：亚毫米波链路的指向性，以及发射器通过自适应电子波束引导和波束形成连接多个接收器的可能性。窄波束宽度的波束形成消除了广播，避免了干扰，使网络操作更加简单，接近网络信息容量的理论上限。该项目旨在演示模块化亚毫米波链路硬件以实现上述目标。拟议的研究将辅以综合教育和外展方案。这包括多元化招聘、指导和保留、实践课程开发、少数族裔高中和本科培训以及公众宣传。跨层科教为下一代无线通信网络的硬件、软件和网络接口提供了新的平台。该项目将在菱形网状网络中开发一个频谱密集、高数据速率、650 ghz的光子无线通信平台，同时明确解决架构中的网络安全和能源效率问题。合作研究跨越物理层、网络层和软件层，解决基础架构中的跨层问题。建议的研究包括三个重点领域。在推力1中，该项目将检查一个模块化的亚毫米波光子链路，该链路基于由该团队最近开发的光学频率梳驱动的芯片级光电混合器。这使得高功率频谱密集，80gb /s亚毫米波传输成为可能。在Thrust II中，该项目将检查一个光子亚毫米波80gb /s测试平台，该平台采用自适应智能天线阵列。波束控制和波束形成将同时实现定向视距（LoS）链路和非视距（NLoS）链路，前者建立一个具有较少符号间和信道间干扰的频谱高效信道。后者减轻了介质的非理想性，如干扰、阴影和多径效应。在第三阶段，该项目将研究亚毫米波通信网络的容量，并探索设计近乎最优的高效和安全算法。利用我们的亚毫米波链路固有的指向性和波束形成能力，该项目将通过物理层安全算法提高无线回程网络无条件安全的可能性。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Wireless communications and networks have experienced exponential growth in data rates and traffic over the past decade, driven by the ever-increasing density of mobile devices, multimedia services and data requirements. The resulting electromagnetic spectrum below 60-GHz has become extremely overcrowded, even with advanced spectrum-efficient modulation formats and spatially diverse multiple-input multiple-output (MIMO) techniques. At present, the sub-millimeter-wave (sub-mm-Wave) electromagnetic spectrum between 300 GHz and 850 GHz is largely unassigned and provides a unique opportunity for more efficient utilization. This will avoid further crowding the currently heavily used spectrum and significantly enhance data rates to tens of Gb/s. This project seeks to demonstrate such a fundamentally new platform towards spectral-efficient and energy-efficient wireless communications with embedded security. Due to the inherent atmospheric attenuation, the sub-mm-Wave communication distance has been limited to within 50 m. Thus, this project proposes network configurations of sub-mm-Wave point-to-point links to enable secured spatial coverage over longer distances and larger areas. There are two distinct differences of the sub-mm-Wave links compared to traditional wireless networks: the directivity of the sub-mm-Wave links and the possibility for a transmitter to connect to multiple receivers through adaptive electronic beam-steering and beam-forming. The beam-forming with narrow beam-width removes broadcasting and avoids interference, enabling much simpler network operation to approach the theoretical upper limits of network information capacity. The project seeks to demonstrate the modular sub-mm-Wave link hardware to achieve the above goal. The proposed research will be complemented with an integrated education and outreach program. This includes diversity recruitment, mentoring and retention, hands-on curriculum development, minority high-school and undergraduate training, and public outreach. The cross-layer scientific and education provides a new platform at the interface of hardware, software, and networks in next-generation wireless communication networks.This project will develop a spectrally dense, high-data-rate, 650-GHz photonic wireless communications platform in a diamond mesh network, while explicitly addressing network security and energy efficiency in the architecture. The collaborative research spans across the physical layer, the network layer, and the software layer, addressing cross-layer issues in the fundamental architecture. The proposed research consists of three thrust areas. In Thrust I, the project will examine a modular photonic sub-mm-Wave link, based on a chip-scale photomixer driven by an optical frequency comb recently developed by the team. This enables high-power spectrally dense, 80 Gb/s sub-mm-Wave transmission. In Thrust II, the project will examine a photonic sub-mm-Wave 80 Gb/s testbed, implemented with an adaptive smart antenna array. Beam-steering and beam-forming will enable simultaneously a directional line-of-sight (LoS) link and a non-line-of-sight (NLoS) link, with the former establishing a spectrally efficient channel with less inter-symbol and inter-channel interference. The latter mitigates medium non-idealities such as interference, shadowing, and multi-path effects. In Thrust III, the project will study the capacity of sub-mm-Wave communication networks and explore the design of near-optimal efficient and secure algorithms. Enabled by the intrinsic directivity and beam-forming capabilities of our sub-mm-Wave link, the project will advance the possibility of unconditional security in the wireless backhaul network through physical layer security algorithms.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.