1-Bit: Ultra Low-Cost, Low-Power Millimeter-Wave Transceiver
Fifth-generation cellular network technology (5G) is already here, at least in part. All four major U.S. carriers have rolled out some form of early 5G in the constant race to satisfy public demand for more and better. Consumers want longer battery life, more robust networks and lower costs for devices and services. They want quicker and more stable access to augmented reality, gaming, and real-time control. In short, they want the next generation of technology before the current one is even mature, which is when commercial devices are typically developed and marketed.
The push for more and better prompted researchers like Bertrand Hochwald, the Freimann Professor of Electrical Engineering and Co-Director of the Wireless Institute (WI) at the University of Notre Dame, and his team to explore the next frontier in wireless communications, specifically millimeter-wave frequencies and gigabit-per-second speeds.
Hochwald and his team are collaborating with researchers from AT&T on a 6G project that’s focused on extremely high frequencies. “The project, titled ‘Ultra-low-cost, low-power millimeter-wave transceivers,’” said Hochwald, “is exploring nontraditional, nonlinear radio architectures in order to create electronics and circuits that can be very low-power and low-cost while not compromising data rates or performance.”
According to Hochwald, the high frequencies of millimeter waves can be both a blessing and a curse. There is an abundance of bandwidth available to support high data rates. However, the technology that operates in these bands is costly and consumes large amounts of power. Additionally, millimeter-wave frequencies have trouble penetrating walls and doors and propagating over long distances. For example, handsets that run these frequencies have a very limited range.
The project tests theoretical and practical concepts as team members work to build a new functioning communication system. Rather than employing a small number of very highly capable power-hungry circuits, the team is using a large number of simple low-power circuits to achieve their goals. “A key factor in the project,” said Hochwald, “is to exploit nonlinear circuits that have been traditionally avoided in communications systems.”
Recently, real-world measurements using specially designed prototypes in a WI testbed demonstrated the feasibility of this novel project, obtaining very high data rates at very low power. The Notre Dame Millimeter-Wave Lab is also being used by the team to assess whether the new transceivers can be competitive with other state-of-the-art transceiver circuits in key performance indicators such as throughput, power, and out-of-band emissions.
Sponsors and Researchers
Notre Dame team members include Hochwald; Jonathan Chisum, assistant professor of electrical engineering; J. Nicholas Laneman, professor and director of graduate studies for electrical engineering and co-director of the WI.
Electrical engineering graduate students Nick Estes, Kang Gao, and Xiangbo Meng.