Thursday, April 18, 2024

Researchers introduce new wireless system for greater 5G access

A team of researchers at the UC San Diego Qualcomm Institute (QI) has introduced a new technique for increasing access to the 5G-and-beyond millimeter wave (mmWave) network.

“Energy grids and mmWave/sub-THz networks share a remarkable similarity; both face fundamental challenges in efficient distribution,” said Dinesh Bharadia, an affiliate of the UC San Diego Qualcomm Institute (QI) and faculty member with the Jacobs School of Engineering’s Department of Electrical and Computer Engineering.

“Just as energy grids generate substantial amounts of energy but encounter significant hurdles in efficiently delivering it to homes, the utilization of mmWave/sub-THz networks for seamless data connectivity presents a similar predicament. Despite abundantly available bandwidth in these spectra, the efficient distribution of data with these spectra to user devices remains a formidable challenge,” he said.

With the introduction of more automation and greater speeds and processing power behind wireless networks, the infrastructure that connects people to these resources has fallen behind. The UC San Diego team was drawn to the challenge of creating a device that could bridge this gap and give people greater access to the 5G mmWave network.

Modern mmWave systems have limited scalability due to inflexibility in performing frequency multiplexing. All the frequency components in the signal are beamformed to one direction via pencil beams and cannot be streamed to other user directions.

Everyone within that beam has access to all resources the 5G mmWave network offers, regardless of whether their devices can process them. This can lead to a waste of bandwidth that might otherwise have been leveraged by users in other regions. Even shifting this beam creates lag for those who fall beyond its range.

To address these issues, researchers set out to determine whether they could create an antenna array that served users in multiple directions without sacrificing distance and power. They designed a prototype device that works in concert with a novel array of antennas to divide a single frequency band into multiple usable beams.

Diagram showing the difference in coverage attainable by a conventional base station (left) and the team’s mmFlexible (right) prototype device and programmable delay-phased array. Conventional arrays can only deliver bandwidth in one direction at a time. mmFlexible splits a single frequency band into multiple “beams” of coverage, for greater range and delivery.
Diagram showing the difference in coverage attainable by a conventional base station (left) and the team’s mmFlexible (right) prototype device and programmable delay-phased array. Conventional arrays can only deliver bandwidth in one direction at a time. mmFlexible splits a single frequency band into multiple “beams” of coverage, for greater range and delivery. Credit: UC San Diego Qualcomm Institute (QI)

Called a delay phased array, this antenna arrangement leverages 5G mmWave’s sheer amount of bandwidth to connect multiple regions to the network and can be tailored to deliver a greater connection to those who need it. The new programmable array can also be built using existing technologies and scaled up with many antennas to support all future devices.

During the experiments, the team found the new flexible mmWave system called mmFlexible decreased lag by 60-150%.

“It’s very exciting to see new generations of applications coming up,” said lead author Ish Kumar Jain. “But I feel, in the future, the number of (wireless) devices will grow, and so will their demand for wireless spectrum. These are the key things that motivate me to further explore these innovative techniques.”

Journal reference:

  1. Ish Kumar Jain, Rohith Reddy Vennam, Raghav Subbaraman, Dinesh Bharadia. mmFlexible: Flexible Directional Frequency Multiplexing for Multi-user mmWave Networks. arXiv, 2023; DOI: 10.48550/arxiv.2301.10950