They are not the only one going beyond the Shannon barrier.
"Hyper-Fi: The patented solution to our $1.5 trillion problem". The hype goes on-- Ruckus Wireless (RKUS),a small company out of California, has created and more importantly, patented a type of super signal that they call "Hyper-Fi". They created a "dynamic" antenna that moves the Wi-Fi signal the same way a lighthouse moves its beam, giving a focused signal for stronger and higher data rates. That works for everyone.. Research shows that delivering all of the expected data will swell the wireless market to $1.5 trillion by 2020.
And this crap - err - farce has been going on for maybe 10 years or so.
Let's just note that I discussed it with one of my sons-in-law, expert in contract law, then a prosecutor, now a judge... I'm clean. ...Jim Thompson
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| James E.Thompson | mens |
| Analog Innovations | et |
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| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
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I love to cook with wine. Sometimes I even put it in the food.
If it's logically impossible, then it's not real. Read the paper.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510
hobbs at electrooptical dot net
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But this paper is based on the obviously false premise that you cannot analyze non-periodic waveforms using the Fourier transform. That's not a "discrepancy from known" -- that's a "1 + 1 = apples".
At some point the fact that they're stupidly or fraudulently wrong will catch up with them. Then we'll be left as much in the dark as we are now.
If the fundamentals are canny and dishonest, then they're squirreling away the venture capital someplace where they'll be able to keep it when things go pear-shaped.
--
Tim Wescott
Wescott Design Services
http://www.wescottdesign.com
If you're going to quote web pages, it might be helpful if you also provided a URL and clearly separate your comments from the quotes.
Ruckus was formed in June 2004. It was formerly called Video54.
The technology your describe is an optional part of the IEEE 802.11n MIMO specification and is called beamforming and beam steering.
802.11n is largely responsible for the higher wireless throughput claims found in current wireless products. (Big numbers are a good thing). It also helps in dealing with multipath cancellation (frequency selective fading) by using multipath reflections to boost throughput as the spatial diversity part of 802.11n.
Whenever this comes up, there's usually some discussion of whether MIMO violates the Shannon bandwidth limit. These might help: "MIMO Spatial Multiplexing" "Capacity Limits of MIMO Systems"
The HyperFi buzzword appears to be a failed attempt to pump up the stock by replacing mundane acronyms and boring technobabble names with something that might be expected to appeal to investors and others that find technology profitable, but quite unfathomable: I don't think I've seen the term used in the last few months.
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
Thanks for all of the responses. I found their math kind of pretty and liked partitioning Taylor's expansion of e^x to form a signal constellation. Besides, who wouldn't want to encode data using complex-plane spirals?
Their idea that somehow the use of exponential high slew-rate symbols (that they admit require faster sampling) somehow avoids adding bandwidth to the signal though is clearly wrong. It's disappointing.
The company just raised $1.5M in seed funding. They are claiming 10x over Shannon.
Shannon's theorem hangs on the original signal being band limited. The reason they may seem to do better is that their non-periodic signal with a growing exponential is not strictly band limited!
You can in principle get a factor of two channel improvement by using the same frequency and two orthogonal polarisations but that is all.
Agreed. Any apparent breaking of the Shannon capacity limit that they might see is due to pumping up the signal amplitude in their new "spiral" basis set. It looks to me like the same basis set apply to the interpretation of NMR spectra so there really is nothing new here.
Maximum entropy analysis of NMR in the 1980's by Sibisi & Skilling explored solving the problem in terms of amplitude across the complex plane - allowing both the frequency and the decay rate to be modelled. There were been earlier solutions by Ernst but theirs was the neatest.
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The NMR basis set are a set of decaying exponentials. You get into trouble if you try to use growing exponentials in any practical system. That is about the earliest I know of where this has been done.
You can extract the optimum solution trading resolution against available local SNR at considerable computational cost. These days with computer time so cheap this is not an unreasonable strategy.
The implicit periodicity of the finite Fourier transform is a mere limitation on the practical case and another red herring. Numerically FFTs can be used to simulate exact classical DFT by suitable gridding functions and post processing to sacrifice aliased edges. Radio astronomy and NMR folks are masters at these techniques.
In fact, the speed limit on most of the Shannon is 6 kph.
That's ~1.7 m/s. In a 1.7m length of canal boat, I reckon you could probably fit 10 million 16GB memory chips, so that puts the Shannon limit at upwards of 1e18 bits per second.
And when it eventually crashes into the supply rail or blows up the final, not even slightly band limited. ;)
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510
hobbs at electrooptical dot net
http://electrooptical.net
Squeezing can in principle improve the SNR if the loss is low enough, but any channel capacity increase still obeys Shannon's theorem.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510
hobbs at electrooptical dot net
http://electrooptical.net
University of Southern California (2013, June 27). Breakthrough in Internet bandwidth: New fiber optic technology could ease Internet congestion, video streaming. ScienceDaily:
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Citat: "... the technology centers on donut-shaped laser light beams called optical vortices, in which the light twists like a tornado as it moves along the beam path, rather than in a straight line. ... Unlike in conventional fibers, OAM modes in these specially designed fibers can carry data streams across an optical fiber while remaining separate at the receiving end. ..."
University of Southern California (2012, June 25). Scientists twist light to send data: Beams of light can be twisted and combined to transmit data dramatically faster. ScienceDaily:
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"... Willner and his colleagues used beam-twisting "phase holograms" to manipulate eight beams of light so that each one twisted in a DNA-like helical shape as it propagated in free space. Each of the beams had its own individual twist and can be encoded with "1" and "0" data bits, making each an independent data stream -- much like separate channels on your radio. ..."
Institute of Physics. (2014, November 11). Twisted light waves sent across Vienna. ScienceDaily
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12 November 2014, 'Twisted light' beamed across Vienna:
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"... He told the BBC the team "really didn't know" whether their idea would work. "We were definitely very surprised that it worked so well." ... At the receiving end, a camera and a computer program recognised the patterns, and re-created the pictures with an error rate of only 1.7%. The researchers hope that their results, although preliminary, will help the development of OAM technology for applications like Earth to satellite communication. ... "This is a proof of principle for how to encode and decode the 16 different channels," said Dr Michael Mazilu, a lecturer in the school of physics and astronomy at the University of St Andrews. ... Mark Neil, a professor of photonics at Imperial College London, was impressed the team had overcome the problem of turbulence in the air. "The big problem was... if you tried to put [twisted light] through a normal atmosphere - you don't have to go very far and it messes up all these OAM modes, and it's difficult to work out what's going on," Prof Neil told BBC News. "So this is quite interesting because they have found a way of unravelling the different modes. They're sending patterns that they can detect." Prof Miles Padgett, who studies twisted light at the University of Glasgow, also said that overcoming turbulence was a major problem that the Vienna study had now begun to address. "It's lovely work," he said. "It shows the potential of the system, and it characterises the problems that people now need to work to overcome." ..."
Jun 25, 2012, Putting a new twist on optical communications:
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OAM even works with a single photon:
Nov 1, 2012, Spooky action with twisted beams:
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"... Using this technique, Zeilinger and co-workers found they could obtain differences in quantum number as high as 600 (in other words l = +300 on one photon and l = ?300 on the other). Lapkiewicz points out that there is, in theory, no upper limit to a photon's l value, which suggests that a photon ? a quantum object ? could acquire as much OAM as a macroscopic object, leading to what he calls a "tension between the quantum and classical worlds". ..."
Feb 12, 2014, Clever technology decodes more information from single photons:
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And with chip transmitters:
Oct 19, 2012, Chip puts a twist on light
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"... Physicists in the UK and China have produced silicon devices measuring just a few thousandths of a millimetre across that can endow light beams with a twistedness associated with orbital angular momentum. The researchers say that by varying this property over a range of values, such devices could increase the amount of bandwidth available for telecommunications and underpin extremely powerful quantum computers. ... The resulting interference pattern showed the hoped-for signature ? a spiral pattern with the right number of arms, given the amount of OAM added to the light. "These spirals are exactly what theory predicts should be seen, so there is no ambiguity at all in our result," says Yu. ... Indeed, he says that they aim to produce devices that can emit different OAM values at the same time. This, he claims, could enhance telecommunication bandwidth, by increasing the number of channels available, and boost the power of quantum computers ? devices, still under development, that promise much faster data crunching by processing multiple quantum states simultaneously. "Currently, quantum computers rely on electron spin or photon spin, which only have two states, whereas OAM has many states," he explains. ..." Science 19 October 2012, Integrated Compact Optical Vortex Beam Emitters:
Yup, more OAM snake oil. Under severe pressure the optical OAM folks have pretty much pulled in their horns on their wilder claims, but these bozos are still trying to cash in.
Shucks, Phil, I missed it again. I really wanted to see the Egress.
Frank McKenney
--
The thing which keeps life romantic and full of fiery possibilities
is the existence of these great plain limitations which force all
of use to meet the things we do not like or do not expect.
-- G.K. Chesterton: On the Institution of the Family (1905)
Has anyone read the paper "A Brief Introduction on Shannon's Information Th eory" by Ricky Chen, arXiv:1612.09316 [cs.IT]? I did not find any error in the arguments there. So, mathematically, it seems there is a little chance that Shannon's limit can be broken in certain channels. Any idea?
No, but I have read one of Shannon's papers from the 1940's. Not only did I find it quite understandable, I think he made his point very well.
If there are channels where the Shannon Capacity can be "broken", it's more likely that the channel is not one that's covered by the capacity theorem than that the theorem itself is faulty.
On the other hand, the claims that I have seen about "breaking" the Shannon capacity theorem read more like arguments for perpetual motion machines than like serious mathematical treatises.
--
Tim Wescott
Wescott Design Services
http://www.wescottdesign.com
I'm looking for work -- see my website!
I was engaged to design circuits for an anonymous company in Tucson who claimed same. I was canned as soon as I started asking penetrating questions.
I suspect they were fleecing investors... claiming many doctors and dentists as investors.
They appear to now be defunct. ...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| STV, Queen Creek, AZ 85142 Skype: skypeanalog | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
Thinking outside the box... producing elegant solutions.
Thanks, Tim. The basic argument in Chen's paper is that, he claimed that given a channel , only sequences satisfying the same statistic distribution were allowed to transmit through the channel in Shannon's original paper. If we are allowe d to pick sequences satisfying any distribution, there might be a chance we can pick more distinguishable sequences than shannon's limit.
My personal question is: why did Shannon only consider sequences satisfying the same distribution? did he prove somewhere that there will be no gain b y considering the general case as Chen did here?
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