Evaluation of Radio-over-Fiber technologies for Distributed MIMO
Licentiatavhandling, 2024
The first part of the thesis describes the background and motivation. Specifically, the system models for the centralized cellular base station and the D-MIMO architecture are described.The second part of the thesis explains different technologies for modulating an RF-signal onto an optical carrier using RoF: digital-radio-over-fiber (DRoF), analog-radio-over-fiber (ARoF) and sigma-delta-over-fiber (SDoF). As the need for power hungry digital-to-analog converters (DACs) is avoided in ARoF and SDoF, they are proposed as primary candidates in D-MIMO implementations. Moreover, measurement results show that SDoF is more robust than ARoF towards non-linearities in an RoF transmitter and inter-channel interference in an RoF receiver.
Finally, a SDoF architecture for D-MIMO with serially connected RRHs is presented. By connecting the RRHs in series the scalability of the system is enhanced, as one fiber link can be used to transmit signals to all RRHs.The serial connection is implemented using wavelength-division multiplexing (WDM), addressing each RRH by a specific wavelength.Through measurement results it is shown that the system with serial connection can perform similarly to one with the RRHs connected in parallel.
To conclude, this thesis presents SDoF as a fronthaul alternative for building robust, scalable and energy-efficient downlinks for D-MIMO networks.The results provide insights into the practical implementation of D-MIMO, a promising architecture for wireless communication systems.
radio-overfiber (RoF)
sigma-delta-over-fiber (SDoF)
distributed multiple-input-multiple-output (D-MIMO)
optical fronthaul
Författare
Frida Olofsson
Chalmers, Mikroteknologi och nanovetenskap, Mikrovågselektronik
Investigation of Fiber Length Differences in Distributed MIMO Sigma-Delta-over-Fiber Systems
IET Conference Proceedings,;Vol. 2023(2023)p. 968-971
Artikel i vetenskaplig tidskrift
Comparison of Transmitter Nonlinearity Impairments in externally modulated Sigma-Delta-over Fiber vs Analog Radio-over-Fiber links
2022 Optical Fiber Communications Conference and Exhibition (OFC),;(2022)
Paper i proceeding
F. Olofsson, L. Aabel, T. Eriksson, M. Karlsson and C. Fager - Sigma- Delta-over-Fiber with WDM Serial Connection for Distributed MIMO
Digital massiv MIMO-över-fiber - en ny energieffektiv radioarkitetur för distribuerade trådlösa system
Vetenskapsrådet (VR) (2019-05174), 2020-01-01 -- 2023-12-31.
Infrastruktur
Kollberglaboratoriet
Ämneskategorier
Telekommunikation
Kommunikationssystem
Signalbehandling
Utgivare
Chalmers
Kollektorn, MC2
Opponent: Dr. Jonas Hansryd, Ericsson