DSPRelated.com

Jeff Brower (@jbrower)

Jeff's engineering management and design experience includes products and systems in the areas of AI, HPC, communications, oil exploration, defense electronics, space exploration, telecom, control systems, acoustic/audio algorithms, and industrial automation. He is a system architect and designer, as well as expert at software, hardware, and logic design, and a range of programming languages and operating systems. Jeff is president & CEO of <a href="http://www.signalogic.com">Signalogic</a>.

Make Hardware Great Again

Jeff Brower June 29, 20205 comments

By now you're aware of the collective angst in the US about 5G. Why is the US not a leader in 5G ? Could that also happen -- indeed, is it happening -- in AI ? If we lead in other areas, why not 5G ? What makes it so hard ?

This hand-wringing has reached the highest levels in US government. Recently the Wall Street Journal reported on a DoJ promoted plan 1 to help Cisco buy Ericsson or Nokia, to give the US a leg up in 5G. This is not a new plan,...


Are DSPs Dead ?

Jeff Brower March 25, 20208 comments
Are DSPs Dead ?

Former Texas Instruments Sr. Fellow Gene Frantz and former TI Fellow Alan Gatherer wrote a 2017 IEEE article about the "death and rebirth" of DSP as a discipline, explaining that now signal processing provides indispensable building blocks in widely popular and lucrative areas such as data science and machine learning. The article implies that DSP will now be taught in university engineering programs as its linear systems and electromagnetics...


TI DSP Predictions

Jeff Brower September 19, 20075 comments

I think it might be interesting to blog a couple of "Texas Instruments DSP predictions". The following are just my opinion, they do not result in any way from inside / confidential information to which I'm privy in working closely with TI for many years. Of course I could be dead wrong, but at least I can say, "if they should occur, it would have a huge impact on the TI DSP developer community".

1) TI will offer real-time Linux running on their DSPs.

With Linux legal...


The Freshers Interview Guide

Jeff Brower September 19, 200720 comments

At Signalogic I'm in hiring mode right now, looking for a couple of entry-level engineers. After several interviews over the last few weeks I find troubling patterns... things young engineers should know, but they don't. Things they put on their resume but shouldn't, things they say or do in the interview they should not, and things they fail to say or do.

Then I see questions for "interview help" on DSP and FPGA tech groups that miss the point, asking about how to do...


Re: Detecting Peaks (Part Deux)

Reply posted 4 weeks ago (11/14/2024)
Hi BigAl, ok ... some stiff constraints. What is your power consumption target and what clock rate are you running ?-Jeff

Re: Detecting Peaks (Part Deux)

Reply posted 4 weeks ago (11/13/2024)
Hi BigAL, I would reply but I replied to your previous post about 3 weeks ago and you didn't respond

Re: Setting prominence in signal.find_peaks

Reply posted 1 month ago (10/31/2024)
Hi BigAl NZ-Slartibart is a top 0.1% radio expert, so he's giving you a sound theoretical basis to explore.Brower on the other hand, knows about audio and video...

Re: Active noise cancellation(ANC) in headphones

Reply posted 2 months ago (10/24/2024)
Hi Andrew,Assuming you are correct, yes state-of-the-art small DSPs can be extremely fast, with 10nm or less process and high clock rates (2-3 GHz). At 2 GHz that's...

Re: FIR coefficient scaling

Reply posted 3 months ago (09/10/2024)
Andrew-Or you can saturate, the old "DSP chip" method. Some source code that does this is here:https://github.com/signalogic/SigSRF_SDK/blob/mast...The limit and...

Re: Group delay in a multirate system

Reply posted 4 months ago (08/08/2024)
Mark-Yes +1 to mention delay until max pattern match.-Jeff

Re: DSP notation

Reply posted 5 months ago (07/15/2024)
TKR-I asked this at one of my first few DSP jobs and was told that all notation arises from Oppenheim and Schafer's famous first book in 1972 (they wrote several):https://www.google.com/search?client=firefox-b-1-d...I...

Re: Deriving velocity from accelerometer data

Reply posted 5 months ago (07/09/2024)
Kousik-First very well presented question and attention to detail. You may be a DSP novice but you will go far.Second, I concur with DJ Maguire, to debug this you...

Re: Future of Signal Processing

Reply posted 6 months ago (06/09/2024)
Hi Omer, yes my thinking is wishful, indeed :-)  But the pressure is on Big AI to find more efficient approaches and create decentralized AI. They can't be using...

Re: Future of Signal Processing

Reply posted 6 months ago (06/09/2024)
No actually not. Big AI's current direction is completely opposite evolution, which prizes efficiency above all else:  https://www.linkedin.com/pulse/sum-all-inference-j... ...

Re: Future of Signal Processing

Reply posted 6 months ago (06/09/2024)
Omersayli"pruning of infinite branches of randomness" ... I don't think we'd even be discussing AI right now if there hadn't been some pruning ! haha-Jeff

Re: Future of Signal Processing

Reply posted 6 months ago (06/09/2024)
Hi Mannai-AI doesn't (can't) replace physics. After all possible information has been extracted from physical signals using available signal processing theory,...

Re: Moving the notches of a Moving Average Filter

Reply posted 6 months ago (06/05/2024)
Hi Engineer68-That's not what I mean. What I'm saying is implement three (3) actual MA filters in parallel: order 16, 15, and 14. Together this is still very few...

Re: Moving the notches of a Moving Average Filter

Reply posted 6 months ago (05/30/2024)
Hi G Medrano,For order 16 MA filter very few FPGA resources would be used ... could you implement orders 14 and 15 and run concurrently ? Then you can use the...

Re: FSK demodulation with repetitive impulse jammer

Reply posted 7 months ago (05/21/2024)
Hi Detlef, looks like a tough problem - no answers so far, and this forum has some of the best and brightest RF and DSP minds.My only thought so far is frequency...

Re: XDS510PP MPSD Emulator

Reply posted 11 months ago (01/17/2024)
Hi Mark-If you're willing to build your own, possibly the Spectrum Digital schematics and firmware have, after so many years, been open sourced or possibly Texas...

Re: meaning of M(QN) notation

Reply posted 1 year ago (11/21/2023)
Hi Robert-Thanks, that makes sense. I couldn't find any clear examples either.-Jeff

meaning of M(QN) notation

New thread started 1 year ago
Hi all-Does anyone know what M(QN) notation means ? For example 15(Q16) ?I'm familiar with QN, QN.M, but not with a leading number followed by parens. I suspect...

Re: Help with PDM filter, please and thanks

Reply posted 1 year ago (10/04/2023)
Hi Jon-If this problem was thrown at me I'd start with this page:https://www.reddit.com/r/DSP/comments/zzelg5/pdm_t...which says implement a sharp lowpass filter...

Re: Help with PDM filter, please and thanks

Reply posted 1 year ago (10/04/2023)
Hi Jon-I searched on "convert PDM to PCM" and found numerous info and examples, including source code, on various sites including ti.com, dsp.stackexchange.com,...

Re: AKM DSP Development?

Reply posted 2 years ago (04/29/2023)
Hi Ekene-Sounds like good progress ! I hope the TI chip works out. One good thing about TI is the chip usually meets and exceeds data sheet specs, and on occasion...
Hi Robert-Thanks for the link to your fixed-point filtering C code, it does look super efficient ! As would be expected from any RBJ authored code.What I've been...
Hi Robert-Thanks. I think I see now how your code works - processes all biquads first, then checks for overflow.I need a shift left function that checks for overflow...
Hi Robert-Thanks, that looks promising. Do you also have code for add, sub, mul, and shift that detects overflow and calls sat() in c55.simul.c ?-Jeff
Hi DGShaw6, thanks !Yes I know of the ITU STL but it has a "General Public License" that disallows modifications, and it needs mods because it has global variables...
All-Does anyone have a link to old Texas Inst C code that simulated what their fixed-point DSPs did with overflow and saturation with arithmetic operations (add,...

Re: AKM DSP Development?

Reply posted 2 years ago (04/04/2023)
Hi Ekene-The block diagram shows coefficient, data, and delay memories, which imply a focus on digital filters. The "PRAM", which I assume is program memory, is...

Re: fft process gain revisited

Reply posted 2 years ago (03/08/2023)
Slartibartfest-"difficult to discern" -- some years ago when I would hire new DSP and software engineers I would pull up Hypersignal and display a huge speech waveform,...

Re: Delay estimation using cross correlation

Reply posted 2 years ago (02/21/2023)
Naumankalia-Is one of the signals altered or degraded in some way ?  If not, then do you have control over one of the signals, for example to insert an "anomaly"...
Hmm it can write a great poem about the Nyquist theorem (all frequencies so nice, they must be sampled twice) but seems to have slightly harder time with actual...

Re: Phase Unwrapping of IQ data

Reply posted 2 years ago (09/30/2022)
Vishnu-> Yes its the I&Q data from the Radar Sensor for each sweep. Ok got it, thanks. I'll be able to spend some time on this over the weekend. Is the data...

Re: Phase Unwrapping of IQ data

Reply posted 2 years ago (09/29/2022)
Vishnu-I took a look at the first .h file, it looks like freq domain data (real and imaginary components). Can you clarify ? What I'm expecting is the original...

Re: Phase Unwrapping of IQ data

Reply posted 2 years ago (09/29/2022)
Vishnu-A couple of quick questions ...1) Your first plot (HumanChestMovmntUnwrappedPhase.jpeg) is actually wrapped phase, correct ?  It looks like phase wraps occur...

Re: Phase Unwrapping of IQ data

Reply posted 2 years ago (09/27/2022)
Vishnu-Then rescale. The point is that in order to know whether your phase unwrapping is working and/or can be improved, we need to see what happens exactly at pi/2...

Re: Phase Unwrapping of IQ data

Reply posted 2 years ago (09/27/2022)
Vishnu Anayady-Can you show the plots with vertical axis gridmarks in multiples of pi/2 radians ?  It would make it easier to give phase unwrapping algorithm...
Amir97-No, not the case at all. My guess is you can stuff all zeros or all 0xffff into the buffer and still see the glitch.  Where in your code you move points...
Amir97-My first thought in seeing your screen grab was "buffer glitch". And your comment:"This distortion always happens after 180 degree phase delay from the starting...

Re: extract analysis and synthesis weighting filters

Reply posted 2 years ago (06/29/2022)
Monk, what's the link for your Stackoverflow post ?

Re: correlation of two complex signals

Reply posted 3 years ago (04/20/2022)
Kaz, excellent. Sounds like you have to do Keysight's documentation for them :-)-Jeff

Re: correlation of two complex signals

Reply posted 3 years ago (04/20/2022)
Kaz-Were you able to get it working ?  I know you are very experienced in signal processing so I'm wondering how this turned out !-Jeff

Re: correlation of two complex signals

Reply posted 3 years ago (04/18/2022)
Dan-"try autocorrelation of one of the sequences with itself"Yes exactly, first debug step to take. And if the OP doesn't see expected result then clearly something...

Re: Help with polynomial zeros

Reply posted 3 years ago (08/07/2021)
Mark-Huh ... I thought MATLAB had open sourced everything. I guess they still subscribe to the Steve Ballmer school of thought about Linux being communism -- they...

Re: Help with polynomial zeros

Reply posted 3 years ago (08/07/2021)
Napierm-Ok ... sounds like a maximum length sequence problem or encryption related. Can you find where in the MATLAB source it fails to converge, and start instrumenting...

Re: Help with polynomial zeros

Reply posted 3 years ago (08/07/2021)
Napierm-Possibly foolish answer here, but since you need stopbands, what about 2 filters in series ?  Maybe that does something to delay for particular stopbands...

Re: Digital IIR Parallel Implementation

Reply posted 3 years ago (06/29/2021)
Philip-Often such a lowpass is written:  y(n) = a*x(n) + b*y(n-1)where a + b = 1 to maintain stability. Looks to me like Charlie's method could still be used, and...
Bulek-We use the EVS encoder to classify incoming audio as voice, background noise, or sound of some type, plus obtain additional confidence metrics for voice.For...
Stephane-Yea but ASR is not DSP. It's deep learning, a subset of machine learning.-Jeff
Stephane-I've been working on real-time ASR (automatic speech recognition), which although codebases such as Kaldi offer a RTF > 1, still pose challenges for...

Re: BeagleBone AI

Reply posted 4 years ago (01/08/2021)
SlartiBartfast-First thanks for your feedback. "it's certainly not the only thing out there" - yes you are so right. Therein lies the root of TI's demise as a semiconductor...

BeagleBone AI

New thread started 4 years ago
All-Has anyone used the BeagleBone AI yet ?  As you may know around 2016 time-frame Texas Inst purged their DSP roadmap and Signalogic was unable to convince them...

Re: Communication between ARM and DSP

Reply posted 4 years ago (12/15/2020)
Alvin-Based on this:https://e2e.ti.com/support/processors/f/791/t/7747...I'd say you have valid concerns, not to mention time spent debugging.Unfortunately it seems...

Re: PMCW Radar for cars

Reply posted 4 years ago (12/14/2020)
Adaptive-My work is in edge computing, specifically where Telcos and hyperscalers meet. I've not been paying attention to technical pros/cons of FMCW vs. PMCW car...
Woodpecker-That was a programmer's answer in the old days, when resources mattered. Now with AI and ML guys, the answer is "we built scalable glasses so don't worry...

Re: DSP Master's Degree

Reply posted 4 years ago (11/26/2020)
No doubt that embedded system engineering in general -- and edge real-time hardware specifically -- pays well. But it pays better if your MS degree emphasizes...

Re: DSP Master's Degree

Reply posted 4 years ago (11/26/2020)
Razed-DSP is no longer a "destination degree". You can visit, but you don't wanna stay for long. I wrote about this here.Over the last 10-20 years of your career,...

Re: Creating your own dev board

Reply posted 4 years ago (11/03/2020)
Dr. Mike-I'm one of those ancients, but not my quote :-)I suggest you expand your reply into a blog. Really valuable words of advice.-Jeff  

Re: short time subband coding

Reply posted 4 years ago (10/21/2020)
niloofar_omidi-ADPCM is normally applied sample-by-sample in the time domain. I'm not clear on your specific technique, but in general trying to adapt this to a...
Skrowten Hermit-If it's attenuated in a mathematical sense, then it should have the same shape -- i.e. should look identical except for values on the y-axis. But...
Mark-Yeah and in the 60s Star Trek covered the singularity ("The Ultimate Computer"), orbit vs. surface class separation (way before Elysium), harsh surface conditions...
Skrowten Hermit-Your attenuated waveform looks odd -- like it's clipped, not attenuated. Definitely cross-correlating x with an attenuated version of x should always...

Re: FSK demodulation with Doppler correction

Reply posted 4 years ago (09/26/2020)
Loganathan-Here is a pic with a 512 pt 1 MHz sine sine wave sampled at 8 MHz, trace a 512 pt FFT, trace b zero-filled to 4096 pt FFT. Trace b is smoother, but underlying...
Neirober-Right, same as flowchart "connector" symbol.  Maybe something indicating type of input inside the symbol (clock, pulse, etc).-Jeff

Re: DSP on Beaglebone AI

Reply posted 4 years ago (09/10/2020)
Graham-As with all chips and evm boards TI makes, it's an excellent piece of hardware -- amazingly small, high performance, low power.  Assuming TI's code development...

Re: DSP on Beaglebone AI

Reply posted 4 years ago (09/09/2020)
Crandles-Unfortunately the general impression is that TI has bailed on AI. Maybe that's not fully accurate but it is accurate to say for today's data scientists...

Re: SDR/DSP Question

Reply posted 4 years ago (08/15/2020)
OnMyOwn-Definitely you can't use DSK C6713 for a new project if for no other reason that it's circa 2003 and you would find it very hard to get support. These days,...

Re: The size of an FIR filter for PDM-PCM conversion

Reply posted 4 years ago (07/17/2020)
Robert-It's like halftoning an image -- the idea is diffusing the error due to 1-bit digitization, shaping the noise and pushing the error into higher freq spectrum....

Re: Sine Dipole formation using two hydrophones

Reply posted 4 years ago (07/13/2020)
Nauman-That sounds good, but in that case you are relying on assumptions that remain unverified -- at least to me, and I would suspect many others viewing your question,...

Re: Sine Dipole formation using two hydrophones

Reply posted 4 years ago (07/13/2020)
Nauman-My apologies I didn't realize your dipole plot is showing amplitude. In that case, why would amplitude for both hydrophones be zero at DOA = 0 ?That makes...

Re: Sine Dipole formation using two hydrophones

Reply posted 4 years ago (07/12/2020)
Nauman-Yes but you have DOA set to 135 deg. That does not sound like equidistant to me.  What happens if you move DOA around ?  Does your amplitude vary ?It "feels"...

Re: Sine Dipole formation using two hydrophones

Reply posted 4 years ago (07/11/2020)
Nauman-If the signal source is not equidistant from the hydrophones, wouldn't you expect an amplitude difference ?-Jeff

Re: DSP chip ??

Reply posted 4 years ago (07/03/2020)
Phil-Even better, how to connect SigmaDSP devices to Raspberry Pi via I2S:https://ez.analog.com/dsp/sigmadsp/f/q-a/65427/con...You can't miss, hehe.-Jeff

Re: DSP chip ??

Reply posted 4 years ago (07/03/2020)
Phil-Maybe have a look at the ADI "SigmaDSP" line:https://www.analog.com/en/about-adi/news-room/press-releases/2017/5-23-2017-analog-devices-next-generation-dsp-for-automotive-audio-applications.htmlThese...

Re: DSP chip ??

Reply posted 4 years ago (07/02/2020)
Phil-Hmm, in that case maybe look at TI's fixed-point C5416 or C5510. These came out in 2000-2006 time-frame, but TI still shows them as "Active". Note the 5416...

Re: DSP chip ??

Reply posted 4 years ago (07/02/2020)
Phil-At first I was going to suggest you use an older DSP, but it would have to much older, 15 years, maybe closer to 20.Another idea is to choose a small, modern...
Stephane-Can you give more advance warning in the future ? This came in while I was another conf call and I couldn't get off in time. These days people may have...

Re: SPI Signal or Something else

Reply posted 4 years ago (06/30/2020)
Ola-There should be either one or no AD7884 pins going to the cable connector: one if they ran Vin+ from the sensor board as a single-ended input without amplification,...

Re: SPI Signal or Something else

Reply posted 4 years ago (06/30/2020)
Ola-First, what is on the sensor board ?  All 3 images you posted are the main board.Second, what is the DSP56002 doing... It has SSI and SCI serial ports, an...

Re: SPI Signal or Something else

Reply posted 4 years ago (06/30/2020)
Ola-What is the DSP type, both mfg and part number ?  How old ?  Agilent was created in 1999 so you might have something built by HP in years prior.  Specific...
Dale-Have you already done some C programming ?  If so then learning C++ is straightforward. If not then I suggest first doing an online course in C. It's like...

Re: Software oscilloscope

Reply posted 4 years ago (06/20/2020)
Steve-You won't need 8 buffers, that's for sure. My suggestion is to first modify your ISR to implement basic triggering, for example a simple amplitude threshold,...
RBJ-That's interesting Farrow has that limitation.Everyone calls out Farrow anytime decimation/interp factors are impractical or other reason fractional resampling...

Re: Software oscilloscope

Reply posted 5 years ago (06/12/2020)
Steven-Answers from Tim and BV Ramesh are on the right track. Additionally you want to abstract timing between acquisition and display/processing. Whatever does...

Re: Help with precoding (SDR implementation)

Reply posted 5 years ago (06/11/2020)
Sumit-Did you work this out ?  It sounded like sachinwannabe had a good debug idea. Did you try that ?-Jeff

Re: Blind De Reverberation

Reply posted 5 years ago (06/04/2020)
Ja Lopez-This music.stackexchange page gives some popular ideas -- as RBJ implies there probably isn't a standard method, and you may need bigger guns.-Jeff

Re: Auto-Correlation based Carrier Frequency Recovery

Reply posted 5 years ago (06/02/2020)
Julein-Could you divide your repetitive pattern into, say 4, patterns that use different sections of your freq domain bandwidth ?  Then take a consensus ... and...

Re: PhD in E.E. is it really worth it

Reply posted 5 years ago (05/09/2020)
Marcin-I'm not sure how to explore internship possibilities on the -related.com sites. I suggest to e-mail the owner/operator Stephane and ask, he's always very...

Re: DDSP combines DSP with a Neural Network

Reply posted 5 years ago (05/09/2020)
Treefarmer-For some minimal inference like basic facial recognition or a wake word. For anything serious, like say Alexa, it's 10+ kW counting servers + GPU boards...

Re: PhD in E.E. is it really worth it

Reply posted 5 years ago (05/08/2020)
Marcin-If you decide yes, my suggestion would be to focus on "EE aspects" of neural networks. By that I mean their architecture, timing, memory costs (energy per...

Re: DDSP combines DSP with a Neural Network

Reply posted 5 years ago (05/08/2020)
Woodpecker-I took a quick look, it does sound interesting.  The current state of the art in speech recognition has turned 180 from the old days, now they depend...

Re: TMS320C6713 Projects

Reply posted 5 years ago (05/03/2020)
Sandukor-Can you get back to your original situation ? I.e. 2 out of 3 test programs working ?  If so I can probably help some, but otherwise if it's a problem...

Re: TMS320C6713 Projects

Reply posted 5 years ago (05/03/2020)
Sandukor-After doing that, do the other test programs still work ?  If not then back up to your original configuration.Basically, if you got 2 test programs working,...

Re: TMS320C6713 Projects

Reply posted 5 years ago (04/27/2020)
Sandukor-Wait not so fast. The point of that page is to show some debug techniques, not give an instant solution. I'm guessing your instructor wants to see that...

Re: TMS320C6713 Projects

Reply posted 5 years ago (04/26/2020)
Sandukor-I did this Google search:  c6713 DSK interrupt test program not working site:e2e.ti.comI didn't see an exact answer but on this thread:http://e2e.ti.com/support/legacy_forums/embedded/t...if...
Artur- If this page contains an accurate ALE diagram, showing a z-delta stage in a discrete time domain signal flow, then the shift would be linear ("traditional"). Using...
Sarah-If they ask you that, you might start by saying that complex numbers started as a math invention (Euler), and now are used everywhere, not just electricity. ...

Re: Setting 25KHz playback sampling rate in sound card

Reply posted 5 years ago (03/25/2020)
Gaurav-What you're asking about is sampling rate conversion (SRC).  Searching on that plus PC sound will bring up Google chatter on the subject.Recently most PC...

Re: MP3

Reply posted 5 years ago (03/03/2020)
Roberto-TI ARM+DSP based SoCs and other vendor (FPGA) SoCs continue to be highly effective solutions to a wide range of problems.  But again, in your case, they...

Re: MP3

Reply posted 5 years ago (03/02/2020)
Roberto-Unless you need to combine MP3 with other audio processing, probably the ASIC approach will give you the lowest cost, footprint, and power consumption. For...

Re: Noise Characterization

Reply posted 5 years ago (03/02/2020)
Dr. Mike-Great reference and article by Mandelbrot himself.  As applicable now as it was in 1999 and 2008.-Jeff

Re: How to obtain impulse response of a room acoustics

Reply posted 5 years ago (01/23/2020)
WestRace-Dudelsound gives an excellent answer.  First, swept sine and MLS (pseudo random white noise) techniques emerged over the years as widely accepted methods,...
Nelson-When you mention "Audacity will add noise to an audio track when downsampling" are you referring to dither ?  I have found a lot of online discussion on...
Zeus101-First, your waveform displays do not match your description.  The first one (orig-spec_65570.png) should show 0 to 16 kHz, if the sampling rate was actually...

Re: phase change

Reply posted 5 years ago (11/18/2019)
Sharan-To see a simple example, multiply a sine signal with period "Fr" number of samples with a unit step that flips the amplitude half-way through:  y[n] = sin(2*pi*n/Fr)*(u[n]-2*u[n-Fr/2])That's...

Re: ADC and Complex Mixer Nyquist question

Reply posted 5 years ago (11/16/2019)
Rick-That is an exceptionally intuitive explanation.  Mixing is rotating after an FFT, I did not think of it that way before.  Thanks.-Jeff
Naumankalia-Are you saying you need multiple passbands, each with different amplitude ?  If so that would be arbitrary frequency response FIR filter design. ...

Re: Average Impulse Response from multiple measurements

Reply posted 5 years ago (08/11/2019)
Samp17-You can think of averaging in the time domain as somewhat of a convolution.  For thought purposes, consider one of your impulses as the input and another...

Re: reconstruct phase-shifted sine tone

Reply posted 5 years ago (08/04/2019)
Iosman-If you shift your already-windowed data in time, you will put the tapered window edges somewhere in the middle of the FFT frame, and create new edges (not...

Re: Machine learning and detection in noise

Reply posted 5 years ago (06/28/2019)
Gabrial-Deep learning is already being used for tone detection in presence of noise, on a far more complex basis than a basic sets of tones -- that's speech recognition.If...

Re: Window Impulse Response

Reply posted 5 years ago (06/26/2019)
Samp17-Normally windowing is needed for sliding FFT analysis, when there is "edge noise" due to sectioning data into frames on an arbitrary basis (i.e. some "frame...

Re: Pool Ball Pendulum Animation in MATLAB

Reply posted 5 years ago (06/13/2019)
Rick-First the snapshots look good.  Seems you indeed have the simulation working correctly.To confirm your chirp theory, you can add spectrogram type output to...

Re: Pool Ball Pendulum Animation in MATLAB

Reply posted 6 years ago (06/11/2019)
Rick-With this are you able to answer the aliasing question ?  Also can Matlab create an animated gif that you can post somewhere and we can see ?-Jeff

Re: Fixed Point Library for Python

Reply posted 6 years ago (06/11/2019)
Sml-Everything "DSP focused" or DSP centric is slowly dying, thanks to TI's brain lock on AI.  Total disaster that is.Deep learning is where you can get extremely...

Re: Sign of the magnitude difference

Reply posted 6 years ago (06/11/2019)
Sudarshan-Hmm seems like they stuck you on a legacy system.  Well, that is engineering, it happens to everyone :)To think about this, consider just real numbers. ...

Re: Sign of the magnitude difference

Reply posted 6 years ago (06/10/2019)
Sudarshan-So what are really saying ?  You cannot simply calculate |z1| -|z2|, for whatever reason ?  I.e. you no longer have z1 and z2 separately, but you do...

Re: Is this time-domain aliasing?

Reply posted 6 years ago (05/27/2019)
Rick-In that case would there be high frequencies we can't see in between balls ?  Could that be tested by hanging some very light weight but stiff strings in...

Re: Spammers are getting more sophisticated

Reply posted 6 years ago (05/21/2019)
Stephane-After deleting the link, can you "lock" the thread ?  And maybe add a little "info" icon explaining reasons why threads get locked.Spammers get more sophisticated,...

Re: AD9601 with 200MSPS connected to DSP

Reply posted 6 years ago (05/16/2019)
J Aranguren-Yes former DSP guys migrating en masse !As Mr. Miyagi would say, you guys have "good chance", probably very good.  TI can't win those seats because...

Re: AD9601 with 200MSPS connected to DSP

Reply posted 6 years ago (05/16/2019)
J Aranguren-A tangent ... I used to work so closely with TI that it felt like I worked there.  Weekly even daily dialogs about various projects and efforts.  Intel...
Andrey-Have you thought about contacting the Wikipedia author and asking whether the "new" terminology should be changed to say "repeated", "updated", or as the...
Szak1592-You:  "I'm pretty sure my code implements the equations for overlap save correctly."Rick:  "I don't think your code is working properly."My money is on...

Re: Todo List: Improvements to the Related Sites

Reply posted 6 years ago (05/02/2019)
Matthew-Right.  User info should include:  1) how many posts, both original and answers  2) upvotes or thumbs-up or something that indicates answer quality ...

Re: picture inter and intra prediction

Reply posted 6 years ago (04/30/2019)
Sharan-I see that you're not getting any replies.  Googling inter vs. intra prediction brings up lots of hits.  One example I found explains what criteria H.264...
learn-Based on your comment about gamma compression, isn't that what you want ?  A gamma of about 0.857 would reduce your number bits from 14 to 12.  It might...

Re: Auto Correlation in DSP processor

Reply posted 6 years ago (03/18/2019)
Mathedoomm-If you're using LabVIEW and testing/simulating solely with PCs at this point, then weetabixharry's suggestion is very good.  Searching for:  autocorrelation...

Re: The Spectral Complexity of a Single Musical Note

Reply posted 6 years ago (03/08/2019)
Rick- I did a quick survey on automatic music transcription.  It sounds to me like it's an even more difficult problem than speech recognition.  Speech also exhibits...

Re: The Spectral Complexity of a Single Musical Note

Reply posted 6 years ago (02/18/2019)
Rick, does the article say anything about mic / data acquisition system specs ?  The plot seems to me a tad suspicious in that "all shape seems to be lost" around...
ReachRF-One comment I might make would be to be careful using the word "domain".  To see Doppler shift you are transforming data from time to frequency domain ......
Nelson-How much "some calculation" are you willing to tolerate and why is there an a-priori need to know ?  The excellent answers from Bholzmayer, Kaz, and Slartibart...

Re: C++ Package for DSP

Reply posted 6 years ago (11/19/2018)
Ahmed-First, I think the core of GNU radio is C++, maybe that's usable for you.  Second you might look at OpenCV.  That's image processing, but their code seems...

Re: Machine learning and detection in noise

Reply posted 6 years ago (09/19/2018)
Tech Nomad-Since you're open to a machine learning solution and seemingly not tied to dedicated algorithms, I would suggest a deep learning approach.  Generate...
Jshowa-> Cause a failure when accessing the array at data[n-1] and data[n-2]> on the first and second iterations?Yes it would, so expanding on my simple example,...
Jshowa-Y(J)S is spot on.  They want to avoid overwriting input data in a short range of 3 points (length of filter, M = 3), so they temporarily use input points...

Re: DC Blocking unexpected results

Reply posted 6 years ago (08/15/2018)
Tony-Great thread with lots of detailed, helpful discussion but seems it's still not completely resolved from your perspective.  I was going back to your original...
Kaz-You forgot MobaXterm and scp, but yeah that sounds about right.  I've used all of these at one time or another, they are effective and easy enough to learn...
Friedman-That made me laugh.  I don't recall being able to do write-in answers for the SAT, but that sure was one case where it was needed.-Jeff

Re: Fundamental frequency of a Guitar string

Reply posted 6 years ago (07/09/2018)
Donvoth-I did this Google search:  FFT algorithm for guitar tuningand the whole first page has good links, including some pro and con discussion on whether to use...

Re: Fundamental frequency of a Guitar string

Reply posted 6 years ago (07/03/2018)
Donvoth-That series of Fujitsu uP has a 10-bit A/D converter:http://www.fujitsu.com/downloads/MICRO/fma/mcu/ds9...My guess is that Roland uses this, acquires a few...

Re: Fundamental frequency of a Guitar string

Reply posted 6 years ago (07/02/2018)
Donvoth-Are you able to see the part number of the Zilog micro ?-Jeff

Re: Fundamental frequency of a Guitar string

Reply posted 6 years ago (06/30/2018)
Donvoth-As other answers have mentioned, converting from a 60 - 6000 Hz time domain waveform to "a series of pulses" is key.  This conversion is the fundamental,...
Dsavio-My comment is in the spirit of the time-worn saying "if something looks too good to be true, then it probably is".  During the process you describe, time...

Re: DSP board selection

Reply posted 6 years ago (06/13/2018)
Naumankalia, you say "DSP board", so in addition to your ADC/DAC specs, the card also needs a DSP ?  If so, what level of processing is needed; i.e. how many cores,...

Re: Inverse filter

Reply posted 7 years ago (06/09/2018)
Kaz-I've calculated:  H(s) = Y(s)/X(s)many times before before but to obtain reliable results I usually had to do two things (i) use 32-bit fixed-point FFT results,...
Kam-With three outputs, and the relatively small size of your ballroom, I think you would be in reasonable shape.  As long as cost is not prohibitive, there is...
Kam-> the dsp can only recognize 3 speakers (left, middle, and right)Does that mean you have three (3) outputs ?> the amp allows me to individually adjust...
Kam-But you only have one output, correct ?  The typical approach is one output per speaker, get the system up and running, then take careful seating measurements...
Kam-Many years ago I used to help guys with sound systems in concert halls, churches, etc.One thing always of concern:  equalizing sound arrival at certain points...
Milad-For IIR filters, group delay is notoriously difficult to measure at frequency response transition regions.  Phase unwrapping has to be performed carefully...

Re: CIC filters with decimation ratio jitter

Reply posted 7 years ago (05/05/2018)
"It pains you", hehe.  Yeah I can see that.  Maybe Ned is wiser than he looks, if he knows the number of samples he consumes (seems like a reasonable assumption)...

Re: CIC filters with decimation ratio jitter

Reply posted 7 years ago (05/04/2018)
JMS-Trying to get a mental picture ... you're saying that you have a sample buffer (or more than one, at 1.024 MHz) and the "downstream consumer" is taking an...

Re: Proper Overflow Adjustment

Reply posted 7 years ago (03/10/2018)
Abb-I think first you may want to be absolutely sure it's overflow or clipping that you have.  My suggestion is to look carefully (zoom in to sample level), starting...

Re: Proper Overflow Adjustment

Reply posted 7 years ago (03/10/2018)
Abb, I'm not clear ... you're using floating-point to look at sampled audio data ?  How did you get the data in the first place ?  Most (by far) audio devices...
Tim, thanks, right.  Theoretically, cascading 1st or 2nd order filers is intended to help.  What I was concerned about is during testing if something is slightly...
Jens-Ok thanks.  My first thought was that cascading anything IIR might run into numerical issues, especially so if fixed-point is somewhere in the picture. ...
Jens-Are you testing filter implementation on a floating-point platform or device ?  Or a fixed-point device ... TI DSP for example.-Jeff

Re: overlapping acquired audio data

Reply posted 7 years ago (02/22/2018)
Max-What analysis are you looking at, if not spectral that would require windowing ?  Windowing is pretty much a spectral processing thing (FFT, wavelet, Gabor,...
Simon-Got it.  For SnapDragon I can't make an OpenCV specific or other recommendation now, but possibly in a month or two, as for a major outfit we're doing a deep...
Simon-Are you unable to answer my question for proprietary or other reasons; i.e. which platform you're using (which CPU or SoC) and how many cores you have available...
Simon-Have you looked at OpenCV ?  What platform are you running on and how many cores ?OpenCV includes image convolution, and has the *potential* to be fast depending...

Re: Artifacts in Time Varying IIR Filters

Reply posted 7 years ago (01/05/2018)
Dan-You have recieved so much great theoretical advice, for sure you will get it working fine.I would like to add some advice on the practical side.  Many years...

Re: AGC on FPGA

Reply posted 7 years ago (11/14/2017)
b2508 I see several good algorithm suggestions here, but assuming your current algorithm is fine as-is, do you have available a faster clock ?  Or can you synthesize...

Re: Estimate battery run-time in real-time

Reply posted 7 years ago (11/09/2017)
Markus-Suggest to take a look at battery manufacturers' data sheets, for example:https://www.duracell.com/en-us/techlibrary/product...or closely related chip datasheet,...

Re: What is Windowing and when/why do we need it?

Reply posted 7 years ago (11/03/2017)
Sometimes we have to teach new hires about windowing on a basic level.  They've already seen it in school, but maybe don't "feel" the need, and just think of it...
Ced yeah I'm not sure either.  I think at one time it was automatic and you had to make an effort to get it to prompt you:https://answers.microsoft.com/en-us/windowslive/fo...Even...
Ced so what you're saying is that JJ, by using the Add Connections Features, essentially gave LinkedIn permission to read the contact list(s) somewhere on his machine,...

Re: audio artifacts sleuthing

Reply posted 7 years ago (09/05/2017)
David - yeah it seems you're pretty good at artifact analysis.  After a lot of prodding we got more info from our customer and they did have issues with their test...

audio artifacts sleuthing

New thread started 7 years ago
I've uploaded a wav file (http://signalogic.com/wav_files/evs_16khz_13200bps_CH.wav) that was produced by extracting payloads from an EVS (codec) pcap sent by our...
It looks like Jaewook means he adapted this to use with the ACF:http://users.monash.edu/~lloyd/tildeMML/KLhttps://stats.stackexchange.com/questions/14673/me...Although...

Re: Need Help In Interpreting Curves in a Chart

Reply posted 8 years ago (05/13/2017)
I would guess (i) they're trying to show a rate, i.e. some number of iterations per sec, (ii) time/s is a time value normalized with another time value (but I have...

Re: Who clones DSP56362?

Reply posted 8 years ago (03/09/2017)
Tony-Does it look something like this:  replacement.com.tw/sst49lf008a.jpgand it's socketed ?-Jeff

Re: Who clones DSP56362?

Reply posted 8 years ago (03/08/2017)
Tony-The 56362 data sheet is here:http://www.nxp.com/assets/documents/data/en/data-s...As Joe mentions, it contains a 30k word program ROM.  In those days (15+...

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