Dispersion from Diffuse Reflectors and its Effect of Terahertz Wireless Communication Performance

TL;DR

This paper studies how surface roughness causes dispersion in terahertz signals, affecting communication performance by increasing symbol errors and limiting data rates, using measurements and stochastic modeling.

Contribution

It introduces a stochastic scattering model for diffuse reflectors and demonstrates its impact on terahertz communication performance through simulations.

Findings

Surface roughness induces group delay dispersion.

A dispersion limit exists beyond which error rates increase significantly.

Surface texturing affects maximum achievable data rates.

Abstract

This work investigates the temporal dispersion of a wireless terahertz communication signal caused by reflection from a rough (diffuse) surface, and its subsequent impact on symbol error rate versus data rate. Broadband measurements of diffuse reflectors using terahertz time-domain spectroscopy were used to establish and validate a scattering model that uses stochastic methods to describe the effects of surface roughness on the phase and amplitude of a reflected terahertz signal, expressed as a communication channel transfer function. The modeled channel was used to simulate a quadrature phase shift keying (QPSK)- modulated wireless communication link to determine the relationships between symbol error rate and data rate as a function of surface roughness. The simulations reveal that surface roughness from wall texturing results in group delay dispersion that limits achievable data rate with low errors. A distinct dispersion limit in surface roughness is discovered beyond which unacceptable numbers of symbol errors begin to accrue for a given data rate.