Collaborative Research: Very-Near-Ground Wireless Channel Modeling: Theory and Practice

本研究的目的是开发无线电波传播的信道模型，其中天线安装在离地面很近的地方（H+），地面水平（H0）和/或被冰、水、雪或其他材料覆盖（H-）。该方法是通过在消声室和真实环境中进行的模拟、分析和测量来评估非常近地天线信道的时间、空间和频谱统计特性。智力优势：所进行的研究包括：1)在广泛的频率范围内开发基于物理的H+/H0/H-无线电信道传播模型，以解决各种应用；2)探索收发天线高度、频率、带宽、粗糙表面材料和粗糙程度对信道模型的影响；3)近地信道频散及其对到达方向和到达时间估计的影响研究；4)研究地面粗糙度和带宽对视距和非视距场景下振幅、相位和到达时间统计的影响，以及空间相关性及其对多输入-多输出系统的影响；5)设计适合H+/H0/H-情况的天线元件和天线阵列。更广泛的影响：这项研究将使无线传感器网络和定位系统的优化设计成为可能，用于自动避碰、多机器人协作、安全服务（消防）和地下勘探等应用，这将有利于国家经济和安全。这个项目将研究与教育和外展活动结合起来。理论工作通过实验室活动和测量过程的实际应用来证明。将为本科生和学校教师提供实践经验。未被充分代表的少数族裔学生将被纳入工程教育。

The objective of this research is to develop channel models for radio wave propagation with antennas installed very near ground (H+), at ground level (H0), and/or covered by ice, water, snow, or other materials (H-). The approach is to evaluate the temporal, spatial and spectral statistical characteristics of very near ground antenna channels through simulations, analysis, and measurements conducted in an anechoic chamber and in real environments. Intellectual Merit: The conducted research includes: 1) development of physics-based propagation models for H+/H0/H- radio channels over a wide range of frequencies to address a variety of applications; 2) exploration of the effect of transmitter and receiver antenna heights, frequency, bandwidth, rough surface materials, and the degree of roughness on the channel model; 3) investigation of near-ground channel dispersion and its impact on direction-of-arrival and time-of-arrival estimation; 4) study of the effect of ground roughness and bandwidth on amplitude, phase, and time-of-arrival statistics in both line-of-sight and non-line-of-sight scenarios as well as spatial correlation and its effect on multi-input-multi-output systems; and 5) design of proper antenna elements and antenna arrays for H+/H0/H- situations.Broader Impacts: This research should enable optimal design of wireless sensor networks and localization systems for applications such as autonomous collision avoidance, multi-robot collaboration, safety services (firefighting), and under-ground exploration, which would benefit the national economy and security. This project integrates research with education and outreach activities. The theoretical work is demonstrated by practical applications through laboratory activities and measurement processes. Hands-on experiences will be provided for undergraduate students and school teachers. Underrepresented minority students will be recruited into engineering education.