Fundamental Performance Limits on Terahertz Wireless Links Imposed by Group Velocity Dispersion

TL;DR

This paper develops a theoretical and numerical framework to quantify how atmospheric group velocity dispersion limits the performance of long-distance, broadband terahertz wireless links, highlighting the importance of dispersion effects over attenuation.

Contribution

It introduces the first predictions of symbol error rate considering atmospheric dispersion effects, providing a new foundation for link budget analysis in terahertz communications.

Findings

Dispersion can dominate error rates over attenuation in long-distance terahertz links.

Increasing signal strength does not necessarily reduce error rates in dispersion-limited systems.

Traditional SNR-based error predictions are invalid for broadband terahertz links affected by dispersion.

Abstract

A theoretical framework and numerical simulations quantifying the impact of atmospheric group velocity dispersion on wireless terahertz communication link error rate were developed based upon experimental work. We present, for the first time, predictions of symbol error rate as a function of link distance, signal bandwidth, signal-to-noise ratio, and atmospheric conditions, revealing that long-distance, broadband terahertz communication systems may be limited by inter-symbol interference stemming from group velocity dispersion, rather than attenuation. In such dispersion limited links, increasing signal strength does not improve the symbol error rate and, consequently, theoretical predictions of symbol error rate based only on signal-to-noise ratio are invalid for the broadband case. This work establishes a new and necessary foundation for link budget analysis in future long-distance terahertz communication systems that accounts for the non-negligible effects of both attenuation and dispersion.