EECE 5698: Terahertz Communications for 6G

Course Description

This course addresses technical aspects for the conception of 6G networks, in which the terahertz band (i.e., the frequencies between 100 GHz and 10 THz) plays a critical role. The course provides a comprehensive view of the enabling technologies, challenges, and opportunities for THz communication networks, from innovative device concepts and propagation channel models to ultra-broadband communication and networking protocols. It combines in-class lectures with analytical, numerical and experimental homework assignments leveraging unique state-of-the-art capabilities in the Institute for the Wireless Internet of Things. The covered topics include terahertz device technologies, terahertz wave propagation and channel modeling, terahertz communications and signal processing, terahertz network architecture and protocol stack, as well as regularization and standardization.

Course Overview

Following the successful commercial deployment of 5G networks, future 6G networks are already being conceived. Currently, both academia and industry (e.g., Apple, Qualcomm, Samsung, Nokia, Huawei) unanimously agree on the critical role that the terahertz band (i.e., the frequencies between 100 GHz and 10 THz) will play in 6G. The very large bandwidth available at THz frequencies (tens to hundreds of consecutive GHz) can alleviate the spectrum scarcity problem while opening the door to Terabit-per-second (Tb/s) wireless links in personal and local area networks, backhaul for urban and rural areas, and even space networks. Moreover, the very small size of THz transceivers and antennas (sub millimetric at THz frequencies) leads to miniature communication devices with applications in wireless networks on chip, wireless nanosensor networks and the Internet of Nano-Things, to name a few. Nevertheless, there are several roadblocks that need to be overcome to tap in the THz band, ranging from the lack of compact and energy-efficient THz sources, high-sensitivity detectors and steerable directional antenna systems, to advanced signal processing, communication and networking techniques that can make the most of the ultra-broadband THz channel while overcoming the challenging propagation characteristics of THz waves.

In this course, a comprehensive view, always providing the necessary background knowledge, of the enabling technologies, challenges and opportunities for THz communication networks will be provided. First, the underlying physics of innovative THz transceivers and antennas will be described. Finite-element method tools will be utilized to explore by simulation innovative THz antenna structures. Second, existing THz-band channel models will be described, for indoor, outdoor and intra-body scenarios. Experimental data sets collected with the TeraNova testbed, a one-of-a-kind experimental platform for 6G developed and hosted at Northeastern University, will be utilized to illustrate and understand the impact of several phenomena on THz waves. Third, communication tailored to the hardware capabilities and channel peculiarities will be presented. MATLAB assignments combined with experimental datasets will be utilized to solidify the concepts behind innovative solutions. Lastly, the foundations for medium access control, spectrum sharing, neighbor discovery and routing in ultra-broadband THz networks will be presented. Network simulations with ns-3 will be utilized to test and visualize the performance of THz networking solutions.

Students successfully completing the course will be in a privileged spot to join the top wireless companies in the nation (e.g., Apple, Qualcomm, Samsung, InterDigital, Keysight, SpaceX…) or to continue an in-depth exploration of the topic in their Ph.D. studies.

Objectives and Expected Outcomes

The objective of this course is to provide students with the necessary knowledge, skills and tools to contribute to the development of 6G wireless communication networks in the THz band.

By the end of the course, students will be able to:

Demonstrate knowledge of the main differences between THz communication networks and traditional wireless networks at lower (microwave, millimeter-wave) and higher (infrared, visible) frequency bands;
Identify and describe the main technologies at the basis of THz transceivers and antennas;
Design and numerically simulate utilizing finite-element-methods (e.g., Feko) radiating ultra-directional antenna systems at THz frequencies;
Demonstrate knowledge of the main phenomena affecting the propagation of THz signals;
Interpret experimental data sets, including channel measurements and transmitted/received data traces;
Design, implement and test different physical layer solutions utilizing numerical tools (e.g., Matlab);
Identify the challenges faced at the link and network layers when designing practical solutions for ultra-broadband THz communication networks;
Demonstrate knowledge of key spectrum regulation and policy challenges at terahertz frequencies.

Module 1: Introduction to the Terahertz Band
1. Properties of Terahertz Radiation
2. Applications in Communications and Sensing at the Macro and Nano Scales
Module 2: Terahertz Device Technologies
1. Technology Pathways to Terahertz Front-ends
  1. Electronics
  2. Photonics
  3. Plasmonics
2. Antenna Systems
  1. Antenna, Antenna Arrays and Reflect-arrays
  2. Lenses and Metasurfaces
3. Ultra-broadband Digital Back-ends
4. Experimental Testbeds for Terahertz Communications Research
Module 3: Terahertz Wave Propagation and Channel Modeling
1. Indoors/Outdoors
  1. Line-of-sight Propagation
  2. Non-line-of-sight Propagation
  3. Multi-path Propagation
2. Extreme Environments
  1. Intra-body Terahertz Propagation
  2. Satellite Terahertz Propagation
Module 4: Terahertz Communications and Signal Processing
1. Modulation
2. Multi-user Interference
3. Channel Coding and Error Control
4. Physical Layer Security
5. Ultra-massive MIMO
Module 5: Terahertz Network Architecture and Protocol Stack
1. Medium Access Control
2. Neighbor Discovery
3. Relaying
4. Routing
Module 6: Regularization and standardization
1. Coexistence of Passive and Active Services above 100 GHz
2. Early standardization efforts: IEEE 802.15.3d

Prerequisites (Working Knowledge of)

If you are a graduate student: there are no formal pre-requisites, but a fundamental knowledge of either wireless communications and networks or RF devices and circuits is helpful.

If you are an undergraduate student:

EECE 2530. Fundamentals of Electromagnetics

AND

EECE 3400. Introduction to Communication Systems (can be concurrent)

Depth/Breadth Designation

This is a depth course for the Communications, Control and Signal processing (CCSP) and Computer Networks and Security (CNWS) concentrations, and breadth for other concentrations in the Master of Science or Ph.D. in Electrical and Computer Engineering (ECE).

This is an elective course in the MS in Wireless and Network Engineering and the MS in Internet of Things.

Organization

Homework Assignments:
- There will be four assignments throughout the semester, consisting of numerical problems that might require the use of MATLAB, Feko and ns-3 as well as experimental datasets.
Exams:
- There will be two open-book exams throughout the semester, consisting of conceptual questions
  - Midterm exam: After Module 3
  - Final exam: Final exam day - TBD

Grading Policy

Grade Distribution:

Homework Assignments: 70%
Midterm Exam: 15%
Final Exam: 15%

Course Materials

All the course materials will be available in Canvas:

Lecture notes
Homework assignments
Laboratory guided assignments
Additional reading materials

Professionalism

As specified in the grading policy, 5% of the grade is based upon the professional behavior and interaction of the students. For this, please

Use professional style in all communications, including email, with course faculty and teaching assistants
Refrain from use of cell phones or other electronic devices unless they are clearly linked to class purposes (e.g., note-taking)
Attendance will be also considered for your professionalism grade including coming to class late. Attendance will be randomly checked in the lectures.
Respect: You are expected to treat your instructor and all other participants in the course with courtesy and respect. Your comments to others should be factual, constructive, and free from harassing statements. You are encouraged to disagree with other students and the instructor, but such disagreements need to be respectful and be based upon facts and documentation (rather than prejudices and personalities). Falling to adhere to this expectation may result in a lower grade. Part of the learning process in this course is respectful engagement of ideas with others.

Expectations of Students

Students are expected to act in a professional manner. A student's grade may be reduced (up to 5%) due to unprofessional or disruptive behavior. Please
- Use professional style in all communications, including email, with course instructors and assistants
- Respect: You are expected to treat your instructor and all other participants in the course with courtesy and respect. Your comments to others should be factual, constructive, and free from harassing statements. You are encouraged to disagree with other students and the instructor, but such disagreements need to be respectful and be based upon facts and documentation (rather than prejudices and personalities). Falling to adhere to this expectation may result in a lower grade. Part of the learning process in this course is the respectful engagement of ideas with others.
To avoid late penalty deductions, assignments should be submitted on or prior to the due date. There will be an automatic 10-point per day deduction in homework assignments submitted past the deadline.
Students are allowed to share ideas regarding homework problems, but each student must independently write and submit their own solution.
Makeup quizzes will be given provided that the two following conditions are simultaneously satisfied:
1. You contact the instructor prior to the exam
2. You have a valid and documented reason to miss the exam
  - Serious illness or family emergency are acceptable excuses
  - Sleeping in, lack of preparation, ennui, grogginess, etc. are not acceptable excuses

Academic Integrity

A commitment to the principles of academic integrity is essential to the mission of Northeastern University. The promotion of independent and original scholarship ensures that students derive the most from their educational experience and their pursuit of knowledge. Academic dishonesty violates the most fundamental values of an intellectual community and undermines the achievements of the entire University.

As members of the academic community, students must become familiar with their rights and responsibilities. In each course, they are responsible for knowing the requirements and restrictions regarding research and writing, examinations of whatever kind, collaborative work, the use of study aids, the appropriateness of assistance, and other issues. Students are responsible for learning the conventions of documentation and acknowledgment of sources in their fields. Northeastern University expects students to complete all examinations, tests, papers, creative projects, and assignments of any kind according to the highest ethical standards, as set forth either explicitly or implicitly in this Code or by the direction of instructors.

Go to http://www.northeastern.edu/osccr/academic-integrity-policy/ to access the full academic integrity policy.

Student Accommodations

Northeastern University and the Disability Resource Center (DRC) are committed to providing disability services that enable students who qualify under Section 504 of the Rehabilitation Act and the Americans with Disabilities Act Amendments Act (ADAAA) to participate fully in the activities of the university. To receive accommodations through the DRC, students must provide appropriate documentation that demonstrates a current substantially limiting disability.

For more information, visit http://www.northeastern.edu/drc/getting-started-with-the-drc/

Diversity and Inclusion

Northeastern University is committed to equal opportunity, affirmative action, diversity and social justice while building a climate of inclusion on and beyond campus. In the classroom, members of the University community work to cultivate an inclusive environment that denounces discrimination through innovation, collaboration and an awareness of global perspectives on social justice. It is my intention that students from all backgrounds and perspectives will be well served by this course, and that the diversity that students bring to this class will be viewed as an asset. I welcome individuals of all ages, backgrounds, beliefs, ethnicities, genders, gender identities, gender expressions, national origins, religious affiliations, sexual orientations, socioeconomic background, family education level, ability – and other visible and nonvisible differences. All members of this class are expected to contribute to a respectful, welcoming and inclusive environment for every other member of the class. Your suggestions are encouraged and appreciated.

Please visit http://www.northeastern.edu/oidi/ for complete information on Diversity and Inclusion.

Title IX

Title IX of the Education Amendments of 1972 protects individuals from sex or gender-based discrimination, including discrimination based on gender-identity, in educational programs and activities that receive federal financial assistance.

Northeastern’s Title IX Policy prohibits Prohibited Offenses, which are defined as sexual harassment, sexual assault, relationship or domestic violence, and stalking. The Title IX Policy applies to the entire community, including male, female, transgender students, faculty and staff.

In case of an emergency, please call 911.

Please visit www.northeastern.edu/titleix for a complete list of reporting options and resources both on- and off-campus.

[1] In a flipped classroom, students are directed to read the relevant related materials before the lecture at home. The time in the classroom is then utilized to solidify the concepts through group discussions and guided examples.