We have now released the 39th episode of the podcast Wireless Future. It has the following abstract: Massive bandwidths are available in the sub-terahertz bands, but the coverage of a cellular network exploiting those frequencies will be spotty. The 6GTandem project tries to circumvent this issue by developing a dual-frequency system architecture that jointly uses the sub-6 GHz and sub-THz bands. In this episode, Erik G. Larsson and Emil Björnson are visited by Dr. Parisa Aghdam, Technical Lead of 6GTandem and Research Manager at Ericsson. The discussion starts with potential use cases, such ..read more

The research community often praises reconfigurable intelligent surfaces (RISs) as a transformative technology. By controlling parts of wireless propagation channels, we can improve the bit rates by increasing the received signal strength, mitigating interference, enhancing channel ranks, etc. The potential benefits RISs can bring to wireless networks are now well documented, and several of them have also been demonstrated experimentally. However, the RIS technology also introduces several practical complications that one must be mindful of. In this blog post, I will give two examples of the ..read more

The way that mobile communication networks are designed changed dramatically with the advent of 5G. In the past, it was all about utilizing large bandwidths and deploying many base stations. Nowadays, we are instead equipping each base station and smartphone with multiple antennas, which enables us to use signal processing algorithms to improve signal strength, enhance reliability, and send more data of the same spectrum by controlling the spatial direction of each signal layer. In essence, we refine the hardware and algorithms instead of deploying more infrastructure and requiring more signal ..read more

We have now released the 38th episode of the podcast Wireless Future. It has the following abstract: Many topics are studied within the 6G research community, from hardware design to algorithms, protocols, and services. Erik G. Larsson and Emil Björnson recently attended the ELLIIT 6G Symposium in Lund, Sweden. In this episode, they discuss ten things that they learned from listening to the keynote speeches. The topics span from integrated sensing, positioning, and localization via machine-learning applications in communications to fundamental communication theory, such as circuits for univer ..read more

The golden frequencies for wireless access are in the band below 6 GHz. Why are these frequencies so valuable? The reasons, of course, are rooted in the physics. First, the wavelength is short enough that a (numerically) large array has an attractive form factor, enabling spatial multiplexing even from a single antenna panel. At the same time, the wavelength is large enough that a sufficiently large aperture can be obtained with a reasonable number of antennas – which, in turn, directly translates into a favorable link budget and high ..read more

We have now released the 37th episode of the podcast Wireless Future. It has the following abstract: We celebrate the three-year anniversary of the podcast with a live recording from the Wireless Future Symposium that was held in September 2023. A panel of experts answered questions that we received on social media. Liesbet Van der Perre (KU Leuven) discusses the future of wireless Internet-of-Things, Fredrik Tufvesson (Lund University) explains new channel properties at higher frequencies, Jakob Hoydis (NVIDIA) describes differentiable ray-tracing and its connection to machine learning, Deni ..read more

We have now released the 36th episode of the podcast Wireless Future. It has the following abstract: It is easy to get carried away by futuristic 6G visions, but what matters in the end is what technology and services the telecom operators will deploy. In this episode, Erik G. Larsson and Emil Björnson discuss a new white paper from SK Telecom that describes the lessons learned from 5G and how these experiences can be utilized to make 6G more successful. The paper and conversation cover network evolution, commercial use cases, virtualization, artificial intelligence, and frequency spectrum. T ..read more

We have now released the 16th episode of the podcast Wireless Future, with the following abstract: The research community’s hype around 5G has quickly shifted to hyping the next big thing: 6G. This raises many questions: Did 5G become as revolutionary as previously claimed? Which physical-layer aspects remain to be improved in 6G? To discuss these things, Erik G. Larsson and Emil Björnson are visited by Professor Angel Lozano, author of the seminal papers “What will 5G be?” and “Is the PHY layer dead?”. The conversation covers the practical and physical limits in communications, the role of m ..read more

One of the physical-layer technologies that have received a lot of attention from the research community in recent years is called Non-Orthogonal Multiple Access (NOMA). For instance, it has been called “A Paradigm Shift for Multiple Access for 5G and Beyond“. In NOMA, the users are assigned to the same time-frequency resource and instead separated in the power or code domains. The core idea of NOMA is to assign the same time-frequency resource to multiple users, and instead (partially) separate the users in the power or code domain. This is illustrated in the figure and stands in contrast to ..read more

We have now released the eleventh episode of the podcast Wireless Future, with the following abstract: 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 ..read more