Investigation of Sigma-Delta-over-Fiber for High-Capacity Wireless Communication Systems
Doctoral thesis, 2023

The advent of beyond-5G (B5G) and 6G technologies brings increases in wireless devices and their applications. Although massive multiple-input-multiple-output (MIMO) delivers high-capacity services using co-located MIMO (CMIMO) technology, distributed MIMO (D-MIMO) technology offers a more uniform user service.

This thesis introduces an automatic D-MIMO testbed featuring a statistical MIMO capacity analysis for an indoor use case. Additionally, raytracing-based simulations are employed for predictions and comparisons in an indoor scenario. The statistical MIMO capacity analysis demonstrates that D-MIMO outperforms C-MIMO in terms of both higher and more uniform capacity, as observed in measurements and simulations.

A promising solution for such future communication systems is radio-over-fiber (RoF). Achieving data rates in the range of several tens of Gbit/s necessitates the utilization of the millimeter-wave (mm-wave) frequency band in RoF. However, mm-wave signals exhibit high propagation loss. Overcoming these challenges requires the incorporation of beamforming and/or MIMO technology in mm-wave RoF systems.

Subsequently, a mm-wave sigma-delta-over-fiber (SDoF) link architecture is proposed for MIMO applications. The first implementation utilizes bandpass sigma-delta modulation (SDM) between a central unit (CU) and a remote radio unit (RRU) through a commercially available QSFP28-based optical interconnect. The implementation achieves symbol rates of 700/500 Msym/s for single-input-single-output (SISO)/multi-user MIMO (MU-MIMO) cases at a 1 m over-the-air (OTA) distance. The second implementation employs lowpass SDM between a CU and a RRH, and reaches 1 Gsym/s with a 1024-quadrature amplitude modulation (1024-QAM) signal across a 5 m OTA distance.

Furthermore, the proposed mm-wave link is extended to two SDoF DMIMO architectures, both incorporating a CU-inherited local oscillator for phase coherence verification. The bandpass SDoF-based D-MIMO system supports a 748 MHz bandwidth with orthogonal frequency-division multiplexing (OFDM) signals for multiple-input-single-output (MISO)/MU-MIMO cases, while the lowpass SDoF-based D-MIMO system operates in the W-band for MISO measurement cases.

In conclusion, this thesis has shown that D-MIMO surpasses C-MIMO in both capacity and uniformity, as validated through statistical analyses from measurements and simulations. The proposed innovative mm-wave SDoF DMIMO architectures lay the foundation for future high-capacity wireless communication networks.

remote radio head

Radio-over-fiber

millimeter-wave

central unit

multipleinput- multiple-output

Kollektorn, MC2, Chalmers University of Technology, Kemivägen 9, Göteborg.
Opponent: Professor Guy Torfs, Ghent University, Belgium.

Author

Husileng Bao

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

Wideband mm-wave Spectrum-Efficient Transmitter Using Low-Pass Sigma–Delta-Over-Fiber Architecture

IEEE Microwave and Wireless Technology Letters,;Vol. 33(2023)p. 1505-1508

Journal article

Flexible Mm-Wave Sigma-Delta-Over-Fiber MIMO Link

Journal of Lightwave Technology,;Vol. In Press(2023)

Journal article

Comparison of Co-located and Distributed MIMO for Indoor Wireless Communication

IEEE Radio and Wireless Symposium, RWS,;Vol. 2022-January(2022)p. 83-85

Paper in proceeding

Demonstration of Flexible mmWave Digital Beamforming Transmitter using Sigma-Delta Radio-Over-Fiber Link

2022 52nd European Microwave Conference, EuMC 2022,;(2022)p. 692-695

Paper in proceeding

Automatic Distributed MIMO Testbed for beyond 5G Communication Experiments

IEEE MTT-S International Microwave Symposium Digest,;Vol. 2021-June(2021)p. 697-700

Paper in proceeding

W-Band Distributed MIMO Demonstration using low-Pass Sigma-Delta-over-Fiber

When tracing the evolutionary trajectory of wireless communication, the landscape has transformed from analog voice communication in the 1G era to the integration of digital data services during the 2G mobile communication phase.The advent of 3G/4G further facilitated global communication through phones, and some regions are already transitioning to the 5G era, with beyond-5G/6G technologies currently under investigation. This advanced wireless communication technology has empowered a multitude of wireless devices with diverse applications.

In recent years, the world experienced the challenges posed by the pandemic, leading to prolonged periods of home confinement for many. Consequently, social activities have predominantly migrated online and some of them remain in the digital realm indefinitely. The surge in online interactions necessitates continued advancements in wireless communication technology. This prompts the question: what else will be seamlessly interconnected through wireless communication in the future?

Consider an autonomous high-speed car receiving real-time traffic updates via a wireless communication link, or a 24-hour automated factory synchronizing with its robotic workforce and providing detailed updates to an offsite owner. In scenarios where tens of thousands of individuals engage in a high-demand sporting event, the simultaneous need for wireless service is necessary. How will future wireless communication technology rise to the challenge of meeting these emerging and complex requirements?

This thesis delves into the realm of fiber-connected wireless communication within mobile communication systems. Through a comprehensive exploration of current research, the study introduces novel architectures and provides experimental validation, particularly in high-frequency bands for distributed multiple-input-multiple-output technology. The proposed innovative solution holds the potential to shape the landscape of future communication networks.

MyWave - Efficient Millimetre-Wave Communications for mobile users

European Commission (EC) (EC/H2020/860023), 2019-10-01 -- 2023-09-30.

Areas of Advance

Information and Communication Technology

Infrastructure

Kollberg Laboratory

Driving Forces

Sustainable development

Subject Categories

Telecommunications

Communication Systems

Signal Processing

ISBN

978-91-8103-025-9

Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 5483

Publisher

Chalmers

Kollektorn, MC2, Chalmers University of Technology, Kemivägen 9, Göteborg.

Online

Opponent: Professor Guy Torfs, Ghent University, Belgium.

More information

Latest update

2/28/2024