First Advisor

Suresh Singh

Term of Graduation

Fall 2024

Date of Publication

12-4-2024

Document Type

Dissertation

Degree Name

Doctor of Philosophy (Ph.D.) in Electrical and Computer Engineering

Department

Electrical and Computer Engineering

Language

English

Subjects

Channel Capacity, Channel model, Communication, MIMO, Reflective surfaces, Terahertz

Physical Description

1 online resource (xiv, 112 pages)

Abstract

Wireless communication has transformed connectivity, enabling seamless access across devices without physical constraints. Terahertz (THz) frequencies, ranging from 100 GHz to 10 THz, promise high-bandwidth channels crucial for applications like IoT and virtual reality. However, deploying THz communication faces challenges due to significant propagation limitations such as high attenuation and environmental absorption. The motivation behind this research is to develop a comprehensive understanding of THz propagation dynamics and utilize reflective surfaces to create multipath environments for an improvement in the capacity performance of MIMO channels.

This research investigates the potential of Multi-Input Multi-Output (MIMO) channels at THz frequencies to overcome these challenges and enhance communication capabilities. The study focuses on measuring, characterizing, and modeling both Line-of-Sight (LoS) and Reflective Line-of-Sight (R-LoS) MIMO channels. Based on these insights, the research also aims to improve MIMO channel performance through innovative reflector designs that create robust multipath environments. By examining various reflector designs around a frequency of 410 GHz, we demonstrate the ability to establish and sustain stable, high-capacity MIMO channels through multiple independent signal reflections. Our static reflective surface (SRS) design incorporates vertically aligned metal strips positioned in front of an aluminum plate, allowing for precise control over reflective elements. This cost-effective solution optimizes reflectors across a wide range of signal paths. The multipath environment created by the SRS design addresses common challenges in both LoS and R-LoS channels, such as channel rank and coverage limitations. Additionally, we have developed a theoretical model for the received signal using our SRS design, achieving strong agreement between predicted and measured capacities. With adjustable design parameters and alignment options, the research identifies optimal SRS configurations that enhance stability while maintaining high channel capacity. This novel approach, combined with the theoretical model, offers cost-efficient reflector solutions for various real-world communication scenarios.

Key outcomes of this research include:

  1. The novel incorporation of a standing wave into the propagation model to generate more accurate predictions of received signals in indoor LoS and R-LoS channels.
  2. An innovative methodology for reflector design using individual reflective elements to create multipath environments, improving the coverage, stability, and capacity performance of MIMO channels.
  3. The development of a theoretical signal model incorporating multipath effects, allowing further exploration of advanced reflector designs to enhance MIMO channels in communication at THz frequencies.

With the above objectives achieved, this dissertation aims to advance THz-based wireless communication systems through innovative signal processing, channel modeling, and reflector designs to overcome existing limitations in signal propagation and channel capacity. By merging theoretical insights with practical advancements, this work contributes to the evolution of telecommunications, enabling faster and more reliable data transfer over THz frequencies. These advancements are crucial for supporting future applications that require unprecedented speed and efficiency.

Rights

In Copyright. URI: http://rightsstatements.org/vocab/InC/1.0/ This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).

Persistent Identifier

https://archives.pdx.edu/ds/psu/42896

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