Principal Investigator: Dr. Hochwald, Department of Electrical Engineering. This project also involves Drs. Laneman of the Department of Electrical Engineering, and Staff Software Engineer Randy Herban.

Project Summary: 

RadioHound, an ongoing project at ND Wireless Institute, is the development of low-cost, portable spectrum measurement sensors capable of tuning over a wide range of frequencies commonly used by everything from cellular phones to wireless local area networks, to radios and televisions. A software platform to control these sensors is also being designed.  One goal is to distribute these sensors over a wide geographical area and thereby crowd-source the real-time measurements to create a “heat-map” of spectrum usage over the area and across frequency. Such a map would be used, for example, to determine where spectrum congestion is dense. We are on version 3.7 of the sensor.

Student’s Role: 

The project has many hardware and software components and opportunities for students to contribute, depending on their technical software and hardware maturities and skillsets. Basic hardware and laboratory capabilities, and knowledge of C, Python, and networking are a plus, but not required. In particular, we have an opening for help with software controlling the board and displaying a spectrum map.  Laboratory measurements, and experimental verification of board performance and spectrum heat-maps will also be performed. Hence, knowledge of laboratory equipment and practices is advantageous.

Principal Investigator: Dr. Laneman, Department of Electrical Engineering

Project Summary: Many industries are expanding their use of wireless technologies, with futuristic applications, ever more connected people and things, utilizing wider bandwidths and higher frequencies, and putting tremendous pressure on access to radio spectrum. Because the radio spectrum is regulated by government organizations at the national and international levels, developing technology and policy innovations to benefit society requires collaboration and interdisciplinary work among business and government leaders, engineers and scientists, economists, lawyers, regulators, and policymakers.

This project enables students to explore a particular spectrum issue, define an engineering problem for coexistence between two or more radio systems, and develop solutions that enable more effective utilization of the radio spectrum. The resulting “prototype” may include a lab-based measurement setup designed to capture a relevant dataset, a software-defined radio (SDR) implementation of a spectrum sharing mechanism, a simulation of models for interfering radio systems subject to proposed policy rules, and associated presentations and reports.

As a concrete example, concerns were recently raised about potential interference between expanded 5G cellular networks and radar altimeters that support the landing of aircraft. Radio propagation and interference models were developed, measurements were taken, and rules were specified to limit the 5G basetation locations, antenna configurations, and power levels around airports. The “deliverables” in this example were reports that summarized the models, propagation and simulation studies, measurement data, and recommendations.

Student’s Role: The REU student will work with graduate students, collaborators, and the faculty advisor to develop coexistence models and solutions. Opportunities to develop reports and participate in various spectrum policy conferences will also be available during the Summer and beyond.

 

Principal Investigators: Dr. Michael Lemmon, Department of Electrical Engineering, and Dr. Bert Hochwald, Department of Electrical Engineering

Project Summary: We seek a student to help model spectrum occupancy over geographic regions as small as buildings and as large as cities. We are analyzing scenarios where a random number of wireless radio transmitters are randomly placed in unknown locations, and with the help of a few sensors that measure signal energy, we can estimate which areas are being reached by these transmitters. Such areas are called “occupied.”

It is especially important to estimate occupancy in the areas that have no sensors from our knowledge of the areas that have sensors. We have found that machine learning methods are especially helpful with this task, where encoder-decoder neural network structures are trained with a large database of scenarios of randomly-placed transmitters and sensors, and where the spectrum occupancy is known in advance, thus providing a training set. 

Student’s Role: We, therefore, seek a student that preferably has:

1) Basic knowledge of machine learning methods

2) Basic knowledge of wireless systems

3) Programming skills (Python, Matlab)

The student will be responsible for helping to train and assess the performance of the machine learning models, and possibly help build a dedicated GPU-based machine to minimize run time.

Principal Investigator: Dr. Striegel, Department of Computer Science and Engineering

Project Summary: One of the major signs that has emerged with the COVID pandemic has been indoor air quality due to its airborne nature. Unfortunately, many of the continuous CO2 monitors are geared towards industrial applications costing hundreds of dollars or are standalone devices (e.g. desk clock) but still approach costs of nearly one hundred dollars. The focus of this work is to explore extremely low-cost, open source CO2 monitors that an individual could order / assemble on their own while offering rudimentary logging / wireless upload capabilities.

Student’s Role: Continue validation work of low-cost CO2 sensors and specify a low-cost / low-power approach with WiFi or Bluetooth capabilities along with a data-gathering back-end and accompanying web or smartphone interface. Stretch goals include the adoption of privacy-sensitive capabilities towards data storage.

Skills To Be Learned: Students will gain skills in C, Python, embedded devices (IoT), WiFi (802.11), and Bluetooth.  Further skills may include database storage / querying (SQL, Postgres) as well as REST API development.

Principal Investigator: Dr. Chisum, Department of Electrical Engineering 

Project Summary: Phased arrays have proven to be an enabler for high-performance communications and sensing in the sub-6 GHz bands. They enable high-gain links to individual remote radios which can be tracked in space to achieve high data rates, enable spatial reuse, and even provide location-aware applications. This technology was initially developed in the defense sector at great cost and with significant power consumption. However, commercial-off-the-shelf (COTS) DACs and ADCs have seen a dramatic reduction in cost and power consumption and a wide range of integrated RF components in the sub-6 GHz bands have become available. These trends have enabled the technology to transition to the commercial sector with great success. 

More recently the same technology was transitioned to the millimeter-wave (MMW) bands (>30 GHz) to enable 5G MMW communications with data rates beyond 1 Gbps. Unfortunately, the technology (data converters and radio components) did not scale well so the 5G MMW phased arrays consume extremely high power. In fact, the first generation of 5G MMW-enabled mobile phones were only capable of operating at Gbps rates for ~10 minutes before the battery was drained. 

Instead of taking technologies that worked well at low-frequencies and moving them up in frequency, an alternative approach is to take technologies which natively work at high frequencies such as lens antennas, and modify them to provide the desired functionality (high-speed beam-scanning and multi-beam apertures) for 5G MMW. 

The purpose of this research project: Is to explore the length to which switch-beam lens antennas can provide the most important features and capabilities of a phased array but at a fraction of the cost and power. This project will build off of the MMW lens antenna demonstrations from the PIs research group and will include theoretical electromagnetic antenna modeling as well as linear systems analysis (especially beam-forming theory and beam-synthesis methods from field theory). If tie permits the student will use the PI’s measurement laboratory and near-field antenna range to demonstrate phased-array-fed lens antennas using state-of-the-art beamformer integrated circuits. 

Student’s Role: The student will survey the network requirements for a realistic MMW wireless network (e.g., 5G NR UWB), perform analysis and simulation of phased array and phased-array-fed lens systems, and determine what sort of feed architectures are necessary in order to support all necessary network functions of a base-station. This includes make-before-break connections, beam management (e.g., UE tracking), support for two separate UEs. The student will perform full-wave electromagnetic simulation of feed antennas and combine them with lens antenna models developed by the PI’s group. This work will use Matlab as well as Ansys HFSS. The work will be supported with guidance from graduate students and the PI.

By the end of the summer, the student will have applied electromagnetic theory and systems analysis to the question of low-power millimeter-wave beam-scanning antennas. The outcome of the work will be an assessment of how well lens antenna systems can accomplish the same thing as phased arrays at a fraction of the power and cost.

Principal Investigator: Professor Monisha Ghosh, Department of Electrical Engineering

Project Summary: Smartphones today contain a large number of radio interfaces that support the various wireless connectivity modes that we use: Bluetooth, Zigbee, Wi-Fi, and cellular being the main ones. These radio interfaces support a number of frequency bands: the unlicensed 900 MHz, 2.4 GHz, 5 GHz, and 6 GHz bands, and cellular bands in the low (< 1 GHz(, mid (1 – 6 GHz), and high (> 24 GHz) bands. Further, Android phones make available a number of Application Programming Interfaces (APIs) that allow one to extract the signal measurements made by these radios: signal strength, signal quality, bandwidth and band of operation, etc. The PI has developed an app, SigCap, that extracts these measurements, exports them, and analyzes the resulting data. Please see https://people.cs.uchicago.edu/~muhiqbalcr/sigcap/ for more details on SigCap and recent papers. In addition to SigCap, which is a passive app, speed test apps such as the FCC Speedtest app will be used to collect measurements on throughput and latency.

Next-generation wireless networks, both cellular (5G, CBRS) and Wi-Fi (Wi-Fi 6E) are evolving rapidly. However, there is insufficient data that can be used to rigorously analyze performance of deployed networks as opposed to theoretical prediction models. This project aims to build data sets that will be useful to the broader research community in understanding how current networks perform and use the results to guide the design and development of future networks.

Student’s Role: The student will use the app on a number of different smartphones to collect data around the Notre Dame campus on 5G, CBRS, and Wi-Fi networks. The data will then be curated, cleaned, and extracted into csv files for analysis of spectrum occupancy and usage in different bands. By the end of the project, the student will have gained knowledge of deployed wireless networks, pertinent measurements, and analysis of the collected data. Depending on student interest, there will also be an opportunity to add features to the app.

 

Principal Investigator: Dr. Fay, Department of Electrical Engineering

Project Summary: Wireless communication systems are increasingly turning to mm-wave frequencies in order to achieve the high-speed transmission needed in next-generation systems.  The use of these higher frequencies challenges the performance of power amplifiers, low-noise amplifiers, switches for reconfigurable RF systems, and filters, as well as the underlying electronic device technologies. This project includes measuring the transistor-level performance of candidate technologies (including DC measurement and high-frequency on-wafer small- and large-signal characterization) and developing models suitable for computer-aided circuit design of these transistors from the measured characteristics. Comparisons of different models (e.g. ASM-HEMT, Angelov, etc.) and their respective abilities to capture key device performance features, particularly with regard to suitability for high-efficiency power amplifiers, are included to evaluate the suitability of the models for different circuit applications.

Student’s Role: The student will also be instrumental in performing the measurements, extracting the model parameters for the selected transistor model, and comparing the model’s projected performance against the measured results. Preparing a design kit, including documenting the model’s strengths and weaknesses, is also included.

Principal Investigator: Dr. Hochwald, Department of Electrical Engineering. This project also involves Drs. Laneman and Chisum, of the Department of Electrical Engineering, and Dr. Striegel from the Department of Computer Science and Engineering.

Project Summary: RadioHound, an ongoing project at NDWI, is the development of low-cost, portable spectrum measurement sensors capable of tuning over a wide range of frequencies commonly used by everything from cellular phones to wireless local area networks, to radios and televisions. One goal is to distribute these sensors over a wide geographical area and thereby crowd-source the real-time measurements to create a “heat-map” of spectrum usage over the area and across frequency. Such a map would be used, for example, to determine where spectrum congestion is dense. We are on our third version of the sensor. 

We are in the eighth year of this project.

Student’s Role: The project has many hardware and software components and opportunities for students to contribute, depending on their technical software and hardware maturities and skillsets. Basic hardware and laboratory capabilities, and knowledge of C, Python, and networking are a plus, but not required. In particular, we have an opening for help with Version 3 of the board, including laboratory measurements, and experimental verification of spectrum heat-maps. Hence, knowledge of laboratory equipment and practices is advantageous.

 

Principal Investigator: Dr. Laneman, Department of Electrical Engineering

Project Summary: The Citizens Broadband Radio Service (CBRS), currently targeting a radio frequency (RF) band centered around 3.5 GHz, represents a breakthrough in wireless technology and policy in the United States. For the first time, widespread commercial cellular networks based upon 4G LTE / 5G NR technology are intelligently utilizing RF spectrum that has otherwise been exclusively reserved for government systems like Navy radars. As RF spectrum becomes more crowded, and sharing spectrum among very different commercial and government systems becomes the norm, wireless system engineers need to build radios and network services that are much more context-aware and collaborative compared to current designs, basically redesigning such systems from the ground up to be more resilience to interference in congested environments.

To address problems in this space, our team has been developing prototypes, models, and algorithms for what is being called a collaborative intelligent radio system (CIRS). A CIRS needs to be able to sense what is going on in the RF spectrum in and around its intended band of operation, and then adapt its transmission formats and receiver signal processing algorithms accordingly. Our radio prototypes are based upon software-defined radio (SDR), with which our team has extensive experience. Student projects involve learning how to use and develop for the prototyping platform, designing and implementing a set of new features, and testing and demonstrating those features to the group.

Student’s Role: The REU student will work with graduate students, a software engineer, and the faculty advisor to develop and test new radio models and signal processing algorithms for CIRS. Opportunities to develop courseware and participate in various wireless and spectrum challenges will also be available during the Summer and beyond.