With funding provided by the Austrian Federal Ministry of Economy, Energy & Tourism and one or more corporate partners, the CD Laboratory “Digitally Assisted RF Transceivers for Future Mobile Communications” at the Johannes Kepler University Linz has now reached the end of its project period, reporting highly positive findings.

Together with their research groups, Professor Dr. Mario Huemer (Institute of Signal Processing) and Professor Dr. Andreas Springer (Institute of Communications Engineering and Radio Frequency Systems) focused on applying digital signal processing methods to boost mobile chip performance in smartphones while simultaneously reducing the chip's power consumption. The solution: New methods, a more targeted use of artificial intelligence, and new chip architectures.

Moving from 4G to 6G
When a company partner, Intel, sold its mobile communications division in 2019, they left the lab, resulting in a period of uncertainty as to whether or not the CD lab would be able to continue to operate for the full eight years. Prof. Huemer remarked: “For a few months, we were not sure how it would all continue.” Fortunately, Apple showed great interest in the JKU's expertise and stepped in to take over the project as well as partially fund the CD lab. Other changes also occurred: “We started out conducting research on 4G and 5G,” says Prof. Springer, but in the end, the technology continued to advance and JKU researchers began experimenting with 6G concepts.

Small Chip, Large Impact
What is it actually all about? Prof. Spring explains: “Essentially, it's about the high-frequency transceiver component in cell phones.” The component is only approximately 8*8 mm in size, but houses the cell phone's transmission and reception modules, which are essential to connect to the internet and make phone calls. This chip has to be reliable but use less power, both of which were issues addressed at the CD laboratory. Prof. Huemer, head of the CD Laboratory, added: "In addition to conventional, so-called statistical signal processing methods, we also applied machine learning methods. Working on this highly application-oriented problem also launched other base-knowledge research activities."

Researchers also created machine learning routines for the small chip, which was particularly challenging given their tiny proportions. In the future, transceivers will be able facilitate making phone calls and connect to the internet as well as record the surrounding environmental conditions to improve data transmission quality.

Impressive Results
At its peak, over 25 scientists and researchers worked at the CD Laboratory. The CD Lab had a budget of approximately €4 million and has now concluded its eight-year period. The outcomes have been immensely successful, producing 70 publications, registering nine patents, successfully supervising 13 completed dissertations and four completed Master's theses. The two CD lab managers added: “Apple then directly hired a number of our employees!”