Friday, January 30, 2009

Interesting projects

These days with RFIC's coming along, interesting ways to make stable microwave oscillators, there are a couple of interesting projects for the radio amateur. Both are moving a little slowly but with help from you gentle reader they could move a lot faster:

Microwave Engineering Project adroitly led by Michelle Thompson, W5NYV and uWSDR led by several good folks. Both are worth investing some time with to see if you can help/enjoy this kind of development. Both are peopled by very strong engineers, hardware and software.

Cheers, N4HY

Thursday, January 29, 2009

No Limits

I joined No Limits for Hillary.

Bayesian Nets, MDL, MCMC, Visual Studio 2008

Today my employer and I agreed to engage Frank Brickle as a consultant for the purposes of working on the application of Bayesian Nets, Minimum Description Length, Monte Carlo for Markov Chains to the problems of cognitive radio. A large bibliography is being prepared for our efforts by several people.

I helped Eric Wachsmann of Flex Radio to port their PowerSDR from MS Visual Studio 2003 .NET to Visual Studio 2008 and to use .NET 3.5.

Wednesday, January 28, 2009

OMAP processor/ Beagle Board

The Beagle Board is beginning to gain some push from inside TI. That is good news. In addition to the recently release free version of Code Composer Studio for these OMAP parts, we find ARM releasing library support, including NEON code (bottom of page) and TI releasing library support for the TMS320C64x . I am assured that more is soon to follow.

Good news! These processors are more than capable of running DttSP SDR core and that port will begin.

Monday, January 26, 2009

At work and play

At work and at play, I am building the infrastructure for filtering and polyphase filter banks in pretty great generality. I have offered to uwSDR that I will be working on devices to do SDR narrow band computation which will enable portable and/or low power computing devices for their use.

My Intel Atom 330 is showing itself nicely. It is also pointing out ugly hot spots in the DttSP core that require the use of resampling to greatly reduce the computational complexity. I HATE to keep giving Microsoft any credit but ... Netflix built a player around Silverlight. It is clear Silverlight is a competitor to flash in some sense. It really is smooth and a great replacement for the Windows multimedia CRAP they had before.

My design of the W8JI eight circle receive antenna for 160m at the home station of Joel Harrison's W5ZN is working out amazingly well. Joel is a real believer now and my design work and construction work appear to be right on the money. Joel has been a fantastic partner in this. He has been continuously comparing his new receive array against his long beverages and finds there is no comparison. He can now hear what he could not detect before. WHEW! One does not want to make the president of the ARRL unhappy!

Saturday, January 24, 2009

Social Commentary

The most inspired social and political commentary of our times: Wazzup

Friday, January 23, 2009

Winter, Second Order Sections

Winter blows! I am not a skier. I am a Southerner. Twenty nine years of living north of Mason-Dixon is not enough to like these winters. On the other hand, I hope it puts a dent into the bug population.

This morning I am putting second order sections into GnuRadio trunk. I cannot believe this and other IIR filtering gadgets are not present.

Thursday, January 22, 2009

Back at work

I am back at work in NJ. I am working primarily on two things. The first is the wrap up of my polyphase filter bank code. This will wind up in GnuRadio, DttSP, HPSDR, and more. Next, with Tom Rondeau, we are trying to get a killer app together for the Cell processor in general, but the PS3 in particular. If we do not succeed, I plan on giving up on the Cell altogether (just as IBM has done in my opinion).

The problem with the Cell is two-fold. First, it is too difficult to program and it is not commodity priced. The former has led to the latter. Graphics cards and GPU's are here to stay. They will be here long after everyone forgets the name Cell BE and they are going to be fast. It is a shame that IBM had so little real interest in pushing this forward and each step of the way I consider major mistakes to have been made that prevented it from catching on. My guess is that the Cell BE 2 will be at best a small make over of the Cell BE and at worst, tossed over the side and handed off to Sony to utterly ruin.

I think the best option overall, for serious high performance software radio computing is the new AMD Phenom, Intel I7, and Nvidia GPU cards sitting in PCIe-16x slots. These will be programmable, with the fast hardware usable by compiling in function calls and/or intrinsics. This will not be optimal, but it will be immediate. It takes over a month just to get linux installed, Cell SDK installed, learn enough to do anything, and then you have to deal with DMA, memory that is too damn small, and very expensive pricing for anything but broken versions (6 SPE versions of Cell in PS3) and their horrible GigE support because we can't have DRM/Video/BlueRay thingy's stolen now can we? BlueRay will also fail to be a big money maker like DVD's. Streaming media is going to nail it to the floor.

Enough prognostication. Back to work!

Tuesday, January 20, 2009

Imperfections in the sublime

The Flex 5000 is one of those pieces of engineering for which I hold great admiration. This is quite natural. My grandfather, a true man of vision, believed strongly in taking things on and owning the issue. I worshiped him until he died before my teenage years. He often asked me, when I was half assing something if I "knew the difference between interested and committed? The chicken that gave you the egg for breakfast was interested. The pig that gave the bacon was committed!" To SDR I am committed, and the Flex Radio company is, to a large extent, responsible. My work was also strongly encouraged by my life long friend, Tom Clark, NASA astronomer, avid amateur, and a fantastic polymath.

The Flex 5000 has my fingerprints all over it. I did not pick the parts that established the circuit functionality in it, but I was most definitely involved in its design. It was a serious step towards a radio device that would meet my needs and allow me to establish certain goals for radio equipment of this type. Gerald Youngblood has been and continues to be a great friend.

Now with all of that behind us, one should never be afraid to admit that there is a thorn on the rose. The quadrature sampling detector is a marvel. It is not perfect, but its perfection is achievable in so many ways with hardware modifications and software additions, it will cause the world to sit up and take notice. It already has and it is 20 dB from its ultimate physical limits of performance.

The quadrature sampling exciter is and will be a mistake. Its imperfections, also correctable, are much more difficult to achieve for many reasons. Slight imperfections, amplified by multi kilowatt amplifiers, are glaring. These are also fixable, primarily in software, but there is no need.

Penelope and any other D/A driven digital up converter is the appropriate foundational element for excellent exciters.

I worked for hours today to put into place a fix for a wart in the 5000 QSE based exciter. It works. But again, this work is putting a band aid, albeit a brilliant one, on an existing device in an existing code base, rather than inventing the new or implementing the "known needed algorithms".

I am sure this message is getting through.

Inauguration Day

Watching the inauguration on television, and feeling good about today, full of hope and good wishes for our new president.

Sunday, January 18, 2009

Yesterday, Today, and Tomorrow

Yesterday I worked fairly hard on the wideband IQ imbalance mitigation problem. It is clear that the correct approach to this problem is to make the performance of the radio better and to ignore the primarily pyschological issue of the sensitive spectrum analyzer display.

The figure below shows the IQ correction for receive strictly limited to the passband of our receiver for the 7 MHz amateur band.

The next figures shows the necessary correction to IQ balance the entire IF passband at one frequency, 7.150 MHz in the Flex 5000. This will be a truly painstaking set of data collection to try and fix the entire wideband problem so the spectral display looks nice when what we should care about is improving the performance of the radio in the passband of the receiver. To do that across the entire 40m band (for example) can be trivially done from the data in the first figure.

The data collection and the new training algorithm will be installed in the PowerSDR code base before I leave. We then take the slower approach to mitigate the perceived wideband problem, which has NO impact on receiver performance but impacts the display. The wideband IQ correction will not easily lower the image to the noise floor across all frequencies. It can and should lower it to near the noise floor and to a greater extent than we currently do.

Yesterday I read most of Neal Stephensen's Snow Crash. He takes a road that combines the troublesome aspects of technology aptly shown in Gibson's Neuromancer and the biting social commentary of Pynchon's Vineland . I am very sorry I have not read him before now. Most place him in cyberpunk. This is not an adequate label.

Tomorrow Eric Wachsmann and begin adding the new IQ algorithms into production, including addressing all of the ugly issues that comes with supporting a large user base.

Wednesday, January 14, 2009

Intel Atom 330, Travel

I am done completely with set up of Intel Atom 330. It is pretty amazing. I suspect that every manufacturer of computers is pretty unhappy with Intel. This is an amazing capable quad thread (dual core HT) machine EM64T. I am running both Windows XP64 and Ubuntu amd64 (x86_64) on it. It will be my dedicated SDR and multimedia TV machine. MythTV, streamer for windows required services (SCREW DRM!!) such as Netflix and Rhapsody,, and more.

I think Blu-Ray is a diller a dollar a ten o'clock scholar. Streaming HDTV streams vitiates any market for Blu-Ray (and large book shelves to store the media).

Off to Austin, Tx tomorrow for a week of SDR work at Flex. This week is dealing almost exclusive with adaptive filtering for all sorts of impediments.

Intel Atom 330

Have completed installing OS's, updating the BIOS, and running several applications on my Intel Atom 330 screwdriver job. I got it on an Intel D945GCLF2 motherboard. The entire computer cost $200 and it outperforms my desktop (old P4 HT), plays excellent quality graphics into my 52" Sony Bravia. The GigE appears to have excellent support under Windows XP and Ubuntu Linux. Both are 64 bit OS's. I am just amazed. It should make for an excellent low end software defined radio dedicated computer as well as streaming machine for my television center.

Tuesday, January 13, 2009

Blackberry Storm

For Christmas I purchased a BlackBerry Storm for my daughter. She updated her phone to version blah.blah.blah.75 and since then there has been nothing but bloody problems. The phone shuts itself off and a battery removal has to be done to recover. This is a damn $500 phone. How in the hell can Blackberry release firmware with this kind of effing mess up in it?

We know this because there are reports of it on Crackberry. We went to Verizon to replace the phone today and they gave us a new one in the box, having blah.blah.blah.75 in it and it has done it TWICE since we got it home.

I am TOTALLY pissed at BlackBerry and Verizon over this stupidity