Surface Wave Wireless Propagation Channel With Antenna Rotation for Industrial Internet-of-Things: Measurement, Modeling, and Analysis

Investigations on surface waves (SW) launchers wireless coupled to a long, single conductor in arbitrary azimuth angles rotation are carried out to inspire a novel SW wireless channel model in Industrial Internet-of-Things (IIoT) environment. A path loss (PL) model with two degrees in freedom, i.e., the coupled azimuth angle α and the transceiver separation <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</i>, is modeled at first. It is revealed that the angular factor governs the excitation degree of the SW propagation mode. Then, a dual-factor root mean square (RMS) delay extension model is developed. Next, the fast-fading distribution is modeled as a nonlinear combination of harmonic functions of the coupled azimuth angle α. It is validated that the PL of the SW propagation mode is reduced by 16~28dB, with the channel impulse response (CIR) principal path level increased by 18dB and the first multi-path suppressed by 7.5dB compared to the free-space propagation mode. Finally, calculations on channel capacity (CC) are performed to demonstrate a CC enhancement of 7~17Gbps. The advanced separation-angle joint channel model is expected to provide useful guidelines in future SW communication nodes deployments in IIoT scenarios.