We have now released the 13th episode of the podcast Wireless Future, with the following abstract:
Wireless devices normally connect to a single access point, deployed at one location. The access points are deployed sparsely to create large cell regions, each controlled by the nearest access point. This architecture was conceived for mobile telephony and has been inherited by today’s networks, even if those mainly transfer wireless data. However, future wireless networks might be organized entirely differently. In this episode, Erik G. Larsson and Emil Björnson discuss how one can create cell-free networks consisting of distributed massive MIMO arrays. The vision is that each user will be surrounded by small access points that cooperate to provide uniformly high service quality. The conversation covers the key benefits, how the network architecture can be evolved to support the new technology, and what the main research challenges are. To learn more, they recommend the article “Ubiquitous Cell-Free Massive MIMO Communications” and the new book “Foundations of User-Centric Cell-Free Massive MIMO”.
You can watch the video podcast on YouTube:
You can listen to the audio-only podcast at the following places:
Mobile networks are divided into semi-autonomous cells. It is essentially a divide-and-conquer approach to network operation, where each cell becomes simple to operate and the reuse of radio resources over the cells can be planned in advance. This network structure was proposed already in the 1950s and has been vital for the wide-spread adoption of mobile network technology. However, the weaknesses of the cellular architecture have become increasingly apparent as mobile data has replaced voice calls as the main type of traffic. While the peak data rates are high in contemporary networks, the user-guaranteed rates are very modest, due to the largest pathloss variations and inter-cell interference that is inherent in the cellular architecture.
A promising solution to these issues is to leave the cellular paradigm behind and create a new network architecture that is free from cells. This vision is called Cell-free Massive MIMO.
This is a technology that essentially combines three main components that have been previously considered separately: 1) the efficient physical-layer operation with many antennas that enabled wide-spread adoption of Massive MIMO in cellular networks; 2) the vision of deploying many access points close to the users, to create a reality where users are surrounded by access points instead of the opposite; 3) the joint transmission and reception from distributed access points, that have been analyzed under many names over the last two decades, including coordinated multipoint (CoMP).
This blog post is about the first book on the topic: “Foundations of User-Centric Cell-Free Massive MIMO” by Özlem Tuğfe Demir, Emil Björnson, and Luca Sanguinetti. We provide the historical background, theoretical foundations, and state-of-the-art signal processing algorithms. The book is 300 pages long and is accompanied by a GitHub repository with all the simulation code. We hope that this book will serve as the starting point for much further research. The last section of the book outlines many future research directions.
NOW publishers is offering a free PDF until April 2, 2021. To obtain it, go to the book’s website, create a free account, and then click on download. For the same period, they are offering printed copies for the special prize of $40 (including non-trackable shipping). To purchase the printed version, go to the secure Order Form and use the Promotion Code 584793.
Since 5G is designed to be future-proof and enable decoupling of the control signaling and data transmissions, I believe that the 5G networks will become increasingly cell-free during this decade, while beyond 5G networks will embrace the cell-free architecture from the outset.
We have now released the twelfth episode of the podcast Wireless Future, with the following abstract:
The data that flows through wireless networks are protected by encryption, but there are anyway privacy and security issues inherent in wireless technologies. In this episode, Erik G. Larsson and Emil Björnson are visited by Panos Papadimitratos, a Professor at the KTH Royal Institute of Technology. The conversation focuses on location privacy and spoofing; what the practical issues are, what countermeasures exist, and which tradeoffs must be made when building wireless technologies.
You can watch the video podcast on YouTube:
You can listen to the audio-only podcast at the following places:
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 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”.
You can watch the video podcast on YouTube:
You can listen to the audio-only podcast at the following places:
We have now released the tenth episode of the podcast Wireless Future, with the following abstract:
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”.
You can watch the video podcast on YouTube:
You can listen to the audio-only podcast at the following places:
We have now released the ninth episode of the podcast Wireless Future, with the following abstract:
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?
You can watch the video podcast on YouTube:
You can listen to the audio-only podcast at the following places:
We have now released the eighth episode of the podcast Wireless Future, with the following abstract:
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.
You can watch the video podcast on YouTube:
You can listen to the audio-only podcast at the following places:
