Fiber Length Estimation Method for Beamforming at millimeter Wave Band RoF-FWA System

Abstract

To supplant partial optical access networks, we study a large capacity transmission system with millimeter wave applied radio over fiber (RoF). In this system, it is desirable from the viewpoints of downsizing and power saving that the base station (BS) is simplified and the central station (CS) controls beamforming. However, this demands fiber length estimation because each wavelength must be given a different phase rotation due to chromatic dispersion in the optical fiber. This paper proposes a method to estimate fiber length from CS to BS supporting wireless terminal (WT) by utilizing time synchronization; its performance is evaluated.