Ep 35. Ten Challenges on the Road to 6G [Wireless Future Podcast]

The main directions for 6G research have been established and include pushing the communication to higher frequency bands, creating smart radio environments, and removing the conventional cell structure. There are many engineering issues to address on the way to realizing these visions. In this episode, Emil Björnson and Erik G. Larsson discuss the article “The Road to 6G: Ten Physical Layer Challenges for Communications Engineers” from 2021. What specific research challenges did the authors identify, and what remains to be done? The conversation covers system modeling complexity, hardware implementation issues, and signal processing scalability. The article can be found here: arxiv.org/pdf/... The following papers were also mentioned: arxiv.org/pdf/... and arxiv.org/pdf/... Music: On the Verge by Joseph McDade. Visit Erik’s website liu.se/en/empl... and Emil’s website ebjornson.com/
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#wireless #wirelessfuture #6g

[@cherie6716]

You should have Ahmad Bazzi up next.

[@ulfg4692]

I'm very happy to see that you guys have picked up some knowledge about radio and microwave hardware. 😀

[@kevenzhong871]

Thanks for your sharing! It's really enlightening for the researchers!

[@AbdulUofG]

That's fantastic imdeed! THANKS for the great knowledge...

[@RenoBlade2]

Hi, I have 2 interesting Points for other Videos. 1. IAB ( Integrated Access Backhaul) and the Possible use cases and 2. Comparison of 8T8R Passive System for 1800, 2100 & 2600 and an 32T32R System for 1800 & 2100. Mostly energy consumption would be nice and coverage gains.

[@WirelessFuture]

Thanks for the suggestions! I believe that IAB is something that we can certainly cover in the future. Comparing different kinds of hardware is generally hard to do without having access to it. However, there is a textbook from Ericsson researchers that contains some simulations and measurements of this kind. It is called “Advanced Antenna Systems for 5G Network Deployments”

[@manuelbeir576]

Thank you, I would come forward with a short question. Such an array has fixed spaces between the elements, so for different wavelength I have a different ratio elem. space/ wavelength. In what cases do we get problems with the transmission? My signal contains different frequencies and every frequency needs a different element spacing to have always e.g. lambda/2. Are there problems with dig. and analog beamforming, or just with analog? Thanks

[@WirelessFuture]

A particular antenna design can only be used efficiently within a limited bandwidth, so you need different antenna arrays for the 3 GHz and 30 GHz bands. When designing the array, it is common to use 0.5*lambda spacing, with lambda being the center frequency of the intended band. The array will be used for a range of different wavelengths, but it typically only varies by something like +/- 10%, so the relative antenna spacing will vary from 0.45 to 0.55. One can use an antenna array even if the relative spacing isn't 0.5. The variations will affect the beamforming pattern: the main lobe shrinks or expands, and the sidelobes are shifted accordingly. But the impact will not be major, so I wouldn't worry much about it. You are right that analog beamforming is more affected by these effects, which can create so-called beam-squinting. One can compensate for this by digital beamforming, or by using true-time-delay components (instead of phase-shifters) in analog beamforming.

[@Julia-hu4xe]

Interesting, thanks. Shortly: when I have a SU-MIMO transmission in a rich scattering environment, I can apply multichannel beamforming. When I am lucky I can e.g. transmit 4 different streams to my UE (4 antennas). My receiver can then process the received signal and get 4 streams back from that mixed signal, right? A mutual interference plays no role in here, yes?

[@WirelessFuture]

Yes, that is how it works. When the transmitter and receiver have perfect channel state information, it can use SVD precoding to achieve the capacity, in which case there is no interference between the streams. With imperfect channel knowledge, there will be some limited interference between the streams that need to be dealt with in the receiver processing.

[@mustafayldrm3449]

Professor, can you make a video or at least give some references about academic writing please? The stuff I find on the internet is for broad range of fields, like life sciences etc. Our field is math heavy. I really struggle during presenting a set of equations. The wording become too repetitive, I often feel I am overexplaining or underexplaining. There is the issue of formatting as well.. For instance I finished my simulations a week ago now but still didnt finish the writing.

[@mousardhwan8268]

Please, i need to know steps to work simulation

[@user-Roblox-mali]

kindly add some details during your talk soo that it could be followed that what current talk is about

[@WirelessFuture]

Thank you for the input! The podcast is produced to function well in the traditional audio-only format, which is why we are not adding additional details in the video. However, we try to always provide paper references for interested viewers who want to know more. There are three references in the description of this episode, and I particularly recommend the first one, which is the basis of our conversation!

[@Shocksdell]

You should have booster #6 to go with the frequency lol

[@sr-gc6vh]

5G and 6G is just marketing, 4G is the peak and tech isn't going to get any better.

[@WirelessFuture]

The traffic capacity of current 5G networks is at least 10-20 times larger than in 4G networks, thanks to more spectrum and Massive MIMO. This benefits users by reducing the risk that the network is overloaded, but you might not see a great difference in your everyday life because user applications didn’t suddenly require 10 times higher data speeds. That said, there is indeed a lot of marketing about future services and use cases that haven’t materialized yet. Some of these things might happen during the next 5 years.

[@WirelessFuture]

The traffic capacity of current 5G networks is at least 10-20 times larger than in 4G networks, thanks to more spectrum and Massive MIMO. This benefits users by reducing the risk that the network is overloaded, but you might not see a great difference in your everyday life because user applications didn’t suddenly require 10 times higher data speeds. That said, there is indeed a lot of marketing about future services and use cases that haven’t materialized yet. Some of these things might happen during the next 5 years.