Analysis of Communication Performance for Head-Mounted Wearable Device

Abstract

To study the channel characteristics and communication performance in the low-frequency UWB band for head-mounted devices, this paper uses the finite difference time domain method, combined with the electromagnetic properties of human tissues, to establish a human head model. It proposes a head transmission system under the low-frequency UWB band, exploring the multipath propagation phenomena during communication. The effects of multipath caused by the human body on communication characteristics are analyzed through power delay distribution, first path power gain, and inter-path delay. The model is validated using the root mean square delay spread; additionally, the feasibility of the head-mounted wearable model is evaluated from the perspective of human safety. The results show that the multipath power delay of the left ear to right ear communication link decays exponentially over time, the power gain changes follow a normal distribution, and the inter-path delays follow a logistic distribution, with an average inter-path delay of 2.75 ns and a standard deviation of 1.25 ns. The cumulative distribution function of the multipath delay spread conforms to an inverse Gaussian distribution, and the peak specific absorption rate of 0.00087 W/kg is significantly lower than the 2 W/kg limit set by the ICNIRP guidelines. © 2025 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.