Wireless Future

The wireless medium must be shared between multiple devices that want to access various services simultaneously. To avoid interference, the devices have traditionally taken turns, which is known as orthogonal multiple access. The use of non-orthogonal multiple access (NOMA) techniques, where the devices are interfering in a controlled manner, was a popular theme in the research leading up to 5G. In this episode, Emil Björnson and Erik G. Larsson discuss the different forms of NOMA, and what their benefits and weaknesses are. They discuss what role NOMA plays in 5G and might play in future wireless technologies. To learn more, they recommend the article “Is NOMA Efficient in Multi-Antenna Networks? A Critical Look at Next Generation Multiple Access Techniques” (https://arxiv.org/abs/2101.04802). Music: On the Verge by Joseph McDade. Visit Erik’s website https://liu.se/en/employee/erila39 and Emil’s website https://ebjornson.com/

5G promises peak data speeds above 1 gigabit per second. Looking further into the future, will wireless technology eventually deliver 1 terabit per second? How can the technology be evolved to reach that goal, and what would the potential use cases be? In this episode, Erik G. Larsson and Emil Björnson provide answers to these questions and discuss the practical challenges that must be overcome at the hardware level and in wireless propagation. To learn more, they recommend the article “Scoring the Terabit/s Goal: Broadband Connectivity in 6G” (https://arxiv.org/abs/2008.07220). Music: On the Verge by Joseph McDade. Visit Erik’s website https://liu.se/en/employee/erila39 and Emil’s website https://ebjornson.com/

In this episode, Emil Björnson and Erik G. Larsson answer questions from the listeners on the topic of reconfigurable intelligent surfaces. Some examples are: What kind of materials are used? When can the technology beat traditional relays? How quickly can one change the surface’s configuration? Are there any real-time experiments? How can the research community avoid misconceptions spreading around new technologies? Please continue asking questions and we might answer them in later episodes! Music: On the Verge by Joseph McDade. Visit Erik’s website https://liu.se/en/employee/erila39 and Emil’s website https://ebjornson.com/

The new 5G millimeter wave systems make use of classical analog beamforming technology. It is often claimed that digital beamforming cannot be used in these bands due to its high energy consumption. In this episode, Erik G. Larsson and Emil Björnson are visited by Bengt Lindoff, Chief Systems Architect at the startup BeammWave. The conversation covers how fully digital beamforming solutions are now being made truly competitive and what this means for the future of wireless communications. To learn more about BeammWave’s hardware architecture visit https://www.beammwave.com/whitepapers. Music: On the Verge by Joseph McDade. Visit Erik’s website https://liu.se/en/employee/erila39 and Emil’s website https://ebjornson.com/

What role will machine learning play in wireless communications? In this episode, Emil Björnson and Erik G. Larsson begin by discussing the fundamentals of machine learning and what it means to “learn” something. They discuss what are the good use cases for machine learning in communications, and what are less convincing use cases. To learn more, they recommend the article “Two Applications of Deep Learning in the Physical Layer of Communication Systems” (https://arxiv.org/pdf/2001.03350.pdf). Music: On the Verge by Joseph McDade. Visit Erik’s website https://liu.se/en/employee/erila39 and Emil’s website https://ebjornson.com/

In this New Year's special, Erik G. Larsson and Emil Björnson answer questions from the listeners on the topic of Massive MIMO. Some examples are: How are the antennas calibrated? Will digital beamforming replace analog beamforming? What is channel hardening and how is it related to power control? Can Massive MIMO interact with drones? Practical issues such as the peak-to-average-power ratio (PAPR) and effective isotropic radiated power (EIRP) are also discussed. Please continue asking questions and we might answer them in later episodes! Music: On the Verge by Joseph McDade. Visit Erik’s website https://liu.se/en/employee/erila39 and Emil’s website https://ebjornson.com/

What happened to millimeter wave communications? It is often described as synonymous with 5G, but barely any of the brand new 5G networks make use of it. In this episode, Erik G. Larsson and Emil Björnson discuss the basic properties of millimeter waves, whether it is the long sought “holy grail” in wireless communications, and where the technology stands today. To learn more, they recommend the articles “Antenna Count for Massive MIMO: 1.9 GHz versus 60 GHz” (https://arxiv.org/pdf/1702.06111.pdf) and “Massive MIMO in Sub-6 GHz and mmWave: Physical, Practical, and Use-Case Differences” (https://arxiv.org/pdf/1803.11023). Music: On the Verge by Joseph McDade. Visit Erik’s website https://liu.se/en/employee/erila39 and Emil’s website https://ebjornson.com/

We are creating a society that is increasingly reliant on access to wireless connectivity. In Sweden, you can barely pay for parking without a mobile phone. Will this wireless future have a negative impact on the security of our data and privacy? In this episode, Emil Björnson and Erik G. Larsson discuss security threats to wireless technology, including eavesdropping, jamming, and spoofing. What impact can these illegitimate techniques have on our lives and what do we need to be aware of? Music: On the Verge by Joseph McDade. Visit Erik’s website https://liu.se/en/employee/erila39 and Emil’s website https://ebjornson.com/

The research towards 6G has already been initiated. One of the most hyped concepts in the research community is “reconfigurable intelligent surfaces”, which can be utilized to create smart walls that capture wireless signals and reflect them towards the user device. In this episode, Erik G. Larsson and Emil Björnson discuss the prospects and limitations of this new technology. Is it the next big thing in wireless? To learn more, they recommend their new overview article “Reconfigurable Intelligent Surfaces: Three Myths and Two Critical Questions”, to appear in IEEE Communications Magazine, which can be downloaded at https://arxiv.org/pdf/2006.03377. Music: On the Verge by Joseph McDade. Visit Erik’s website https://liu.se/en/employee/erila39 and Emil’s website https://ebjornson.com/

There are often hypes and speculations around new wireless technologies, including “Massive MIMO”, which is the key new feature in 5G. In 2015, Emil Björnson and Erik G. Larsson wrote the article “Massive MIMO: Ten Myths and One Critical Question” together with Thomas Marzetta. It was an attempt to dispel some of the misconceptions that were floating around at the time. In this episode, they look back at the statements they claimed to be myths to see if they were right and whether the myths are still around. The article received the 2019 Fred W. Ellersick Prize from the IEEE Communications Society and can be downloaded at https://arxiv.org/pdf/1503.06854. Music: On the Verge by Joseph McDade. Visit Erik’s website https://liu.se/en/employee/erila39 and Emil’s website https://ebjornson.com/