Propagation Distance Estimation for Radio over Fiber with Cascaded Structure

TL;DR

This paper proposes a non-linear least-squares method to accurately estimate the propagation distance of sub-THz signals in a cascaded radio over fiber system, considering non-linear distortions and fiber effects.

Contribution

It introduces a novel estimation approach for propagation distance in cascaded radio over fiber systems with non-linear effects, validated through simulations.

Findings

Proposed estimators achieve accurate distance estimation.

Estimation performance remains robust despite non-linear distortions.

Simulation results confirm effectiveness in cascaded structures.

Abstract

Recent developments in polymer microwave fiber (PMF) have opened great opportunities for robust, low-cost, and high-speed sub-terahertz (THz) communications. Noticing this great potential, this paper addresses the problem of estimation of the propagation distance of a sub-Thz signal along a radio over fiber structure. Particularly, this paper considers a novel cascaded structure that interconnects multiple radio units (RUs) via fiber for applications in indoor scenarios. Herein, we consider the cascaded effects of distortions introduced by non-linear power amplifiers at the RUs, and the propagation channel over the fiber is based on measurements obtained from transmissions of sub-THz signals on high-density polyethylene fibers. For the estimation of the propagation distance, non-linear least-squares algorithms are proposed, and our simulation results demonstrate that the proposed estimators present a good performance on the propagation distance estimation even in the presence of the cascaded effect of non-linear PAs.