## Re: Should work but doesn't (and vice versa)

Thanks for the link, Rick.  I have done the Rader/Gold quadrature oscillator myself with the 56K back around 1992.  I had to have the fixed-point coefficients...

## Re: Should work but doesn't (and vice versa)

>"Also, different initial conditions (what you call y[n-1] and y[n-2]) didn’t seem to have any discernable effect on the output of my resonator."Of course,...

## Re: Should work but doesn't (and vice versa)

Did you do this?:    y[n] = (2 cos(Ω))y[n-1] - y[n-2]initial states (given the parameters, A, Ω, φ):    y[-1] = A cos(-Ω + φ)    y[-2] = A cos(-2Ω + φ)And...

## Re: Should work but doesn't (and vice versa)

So then, I would expect that, even if the resonant sinusoid from the noise is at some random (and slowly changing) phase, it would team up with the intended sinusoid...

## Re: Should work but doesn't (and vice versa)

If it's additive, it's a source.  Use superposition.  But, of course, modeling quantization error as additive noise is an assumption.  With the non-linear reality,...

## Re: Should work but doesn't (and vice versa)

"The effect of quantized coefficients is that the oscillator's poles stay on the unit circle but their angles become shifted from the desired angle."I understand...

## Re: Should work but doesn't (and vice versa)

About a quarter century ago, I was schooled a little by James McCartney (creator of SuperCollider) about this simple sinusoidal oscillator:    y[n] = (2 cos(Ω))y[n-1]...

## Re: DSP Processing on ARM Cortex M (FREE BOOK)

Kewl!I recognize your "73" from my ham radio days 4 decades ago.  (I used to be WB∅CCA.)So have you made little radio widgets with an ARM processor?  From bare...

## Re: Electromagnetic waves question

Long time ago (45 years), I took a class in antenna design and it was like an analog signal processing class.  Like using Tchebyshev polynomials to design antenna...

## Re: Matlab support for "Frequency-Response Masking" filter design technique

I had explored this title before and I could not make it work as promised.  It seemed to me to be a little "something for nothing" trick, which also means "If it...

## Re:

What's the application?If you can edit your original post, you might wanna give it a title.

## Re: C code simulation of DSP fixed-point operations with overflow and saturation

It looks like you're reviving a TI application.  But if you're doing filtering in fixed-point with a general-purpose CPU (that doesn't do floating point), I have...

## Re: Quantizing the feedback coefficient in the Goertzel algorithm

It's the denominator coefficients, a1 and a2, that are getting quantized.The specific frequency might be off, due to quantizing a1, but the radii of the pair of...

## Re: Is there any DAC math model around?

There aren't really any DACs that output a sinc function for each sample.  That would be really ideal (in a theoretical sense) but it's a mathematical model for...

## Re: State Space Model Perspective of Different IIR Filters Realizations

They do.  I would have to find the right textbook or paper.  Maybe Julius Smith has it spelled out.  Look at https://ccrma.stanford.edu/~jos/fp/Converting_Stat...BTW,...

## Re: State Space Model Perspective of Different IIR Filters Realizations

The state space model (like we get when we take a Control Systems course) is much more general.  I.e. the very same transfer function can be implemented multiple...

## Re: Whatever happened to "Wavelets"?

But the same can be said for the Short-Time Fourier Transform (STFT).But, as best as I can tell, the analysis window of a wavelet transform gets smaller for higher...

## Re: Loop optimization in C6416T Processor

Well you're doing a mpysp() operation (and a complex addition, which doesn't cost much) 280,000 times. Why does one run cost 192 instruction cycles?And is this...

## Re: Essential DSP Knowledge for Embedded Systems Engineers

fixed point or float?

## Re: DSP "digital complex limiter" "crest factor" - digital audio soft clipping

Dean,In the digital signal world, the waveform is made up of numbers.  A stream of numbers called "samples".  There isn't an "energy" in the sense that you have...

## Re: Low-pass filter image data

this is what i meant to say, but when i hit "Submit Reply", the response was something like "You must be logged in to reply" and it totally lost about 5 or 6 paragraphs.as...

## Re: Low-pass filter image data

does this work or did dsprelated just eat my reply to Tim?

## Re: Low-pass filter image data

i really dunno diddley, Tim, but isn't the DCT (there are four or five forms) essentially a DFT of 4 times the size (twice in X and twice in Y) where the added...

## Re: Communication between ARM and DSP

Not sure your company wants to consider it but Analog Devices has a relatively new fire-breathing SoC that has an ARM and two SHArC DSPs on one chip.  But I dunno...

## Re: Suggested Midterm for a class in Error Correcting Codes

so there are 26 letters and 10 numerals.  i remember old typewriters had "l" for "1" and "O" for "0".  but that only gets you down to 34.  what other symbols...

## Re: Suggested Midterm for a class in Error Correcting Codes

never learned Baudot-Murray nor Reed-Solomon.  more familiar with Linkwitz-Riley or Sallen-Key or Karplus-Strong.i know a little about error detection, but little...

## Re: Sampling and using the data

What utility or application are you using to "place [your] frequency marker"?

## Re: FFT stitching

kaz, even doing a butterfly is implementation dependent, i think, because how you gotta handle the indexing of the two in-place bins and then doing the add/subtract...

## Re: Advice for FM Demodulation Techniques

So you "have a quadrature FM signal that is modulated on a low frequency IF" which sounds to me that you have both \$i[n]\$ and \$q[n]\$ of a complex signal that...

## Re: MSc Digital Audio Engineering Project Idea

Okay, do you know what "Convolutional Reverb" is?  What "Fast Convolution" is?Do you know what the Schroeder Reverb model is or the Jot Reverb model?  There might...

## Re: Designing an IIR comb (peak) filter

it turns out that *every* digital filter is a comb filter (of sorts).  if the digital filter is a LPF, you will see comb teeth at every integer multiple of the...

## Re: Carrier doppler shift and Signal doppler shift

i do not see why the Doppler shift effect should be any different for the modulation than it is for the carrier.  the whole signal gets scaled in time by a single...

## Re: Correlation between a signal segment and its stretched replica

okay, i understand this statement: "I have used a Farrow interpolator to do fractional rate sample rate conversion on only one of the signals..." but i am curious...

## Re: Correlation between a signal segment and its stretched replica

if you're interpolating (or sample rate converting) the stretched replica to make it the same length as the original signal segment, how do you know what the sample...

## Re: A low sensitivity and limit-cycle-free IIR filter implementation

well, i don't have the fixed=point toolbox, but if you're plagued with limit cycles due to round-to-nearest quantization, my suggestion is that you use a technique...

...

## Re: FFT Interpolation

But then you have to toss in the modulo indexing in order to use the theorems in your "(i.e., discrete Fourier transform)".  That modulo indexing makes it periodic.Uniform...

## Re: FFT Interpolation

I would replace the word "finite" with "periodic".

## Re: Adaptive Filter Theory: prequisites to learning

Stephan, your implementation of $$\LaTeX$$ here leaves a bit to be desired.  It works erratically.  especially when i edit a post that had math previously appearing.if...

## Re: FFT Interpolation

Well, this is an old issue with me and Eric that dates back to the mid 1990s on comp.dsp .  I must differ with Eric where he writes:"There do not need to be any...

## Re: A low sensitivity and limit-cycle-free IIR filter implementation

I don't see any truncation or cast to a fixed-point value or any nonlinearity.  So I don't understand what the source of any limit cycle would be.At least, in my...

## Re: Adaptive Filter Theory: prequisites to learning

The very basics of the LMS adaptive filter are not all that difficult to understand.  Perhaps ask a question about it at the Signal Processing Stack Exchange and...

## Re: FIR filter shortening technique

yeah, what John says.  because reducing 1024 degrees of freedom down to 3 degrees of freedom might not so good.  even if your FIR taps are not adjacent to each...

## Re: Fixed point exponentiation

i do now.  but it looks a little Maclaurenish to me.  since, ultimately, the power series will have to be finite (which is a polynomial), you will want (slightly) different...

## Re: Fixed point exponentiation

but can't you develop a Cordic operation based on 2^x instead of e^x just as efficiently?  there might be an internal scaling operation in there that would be different...

## Re: Fixed point exponentiation

it just seems to me, Brian, that especially for a fixed-point implementation, that 2^x is the simplest primitive and then use A^x = 2^(x*log2(A)).When it's base...

## Re: Fixed point exponentiation

In this stackexchange answer are the coefficients for some short finite-order polynomials for evaluating (at a pretty good accuracy) a bunch of transcendental functions...

## Re: Clock drift and compensation

well, it appears to me that you will need to perform Asynchronous Sample Rate Conversion (ASRC).  there are chips to do that, but if you have the sufficient unused...

## Re: need help with adsp21489 ezkit programming

Okay, so I know the SHArC core instruction set pretty well and some of the key features that existed in the SHArC back in the olden daze (like 1995 with version...

## Re: need help with adsp21489 ezkit programming

Do you have an ICE-1000 or some JTAG emulator with this EZKIT?If you don't use a JTAG emulator, I s'pose ADI provides some means of loading and running code, but...

## Re: Aliasing in Radix-2 FFT - Decimation in time

"If the DTFT of a sequence has a bandwidth omega_max > pi/2, a downsampling by a factor of 2 is surely going to cause aliasing in the resulting DTFT."Yes it will. ...

## Re: Aliasing in Radix-2 FFT - Decimation in time

Similarly to some filterbank and wavelet transforms, there is perfect reconstruction because the aliases have a way of killing each other off.But when thinking about...

## Re: What's your favorite modern DSP chip?

I still have yet to really do any work on an ARM even though I am told that some C code I wrote (and tested with Xcode) found its application on a phone running...

## Re: Choosing the DFT size to match linear convolution in overlap save method?

I am only responding to the title of the post.It seems to me that not very many books that describe fast convolution consider the optimal size for the FFT and most...

## Re: How to model analog effects and create convolvers.!!

There is more to the various "analog effects" than filters and convolution.  If you're trying to simulate a guitar amplifier with different cabinets, perhaps the...

## Re: Time delay

no.  it's an alternative way of doing it.  using polyphase FIR, you have coefficients for an FIR filter for every fractional delay you want.Let's say your FIR...

## Re: Spectral distortion measure - Itakura-saito distance

i have never heard of the "Itakura-saito distance" before.  i did know about the Log-Spectral distance which is in dB.the form of this the integrand is (x-1) -...

## Re: As easy as PI

I dunno.  Sometimes mathematics is useful for economic analysis and projections that should influence politics.  It's politically useful to understand a runaway...

## Re: How closely are control engineering and DSP related?

Not only is knowledge in DSP **very** useful designing digital controllers, but Control Theory has some concepts that are useful for DSPers that never got paid...

## Re: Time delay

So my understanding is that you want a fractional-sample delay, where you specify in advance how much delay you want.1. If the delay is a fraction of a sample less...

## Re: Application of computer with invertible arithmetic?

yeah, it was Sokolich (who was around the alt.sci.physics.acoustics newsgroup when it was active) not the goofy brit named Gareth.didn't remember that i was scraping...

## Re: Application of computer with invertible arithmetic?

well, i never much hung around these specific parts.  this might be my very first DSPrelated post.i remember Bob Cain from the comp.dsp daze.  if i remember right,...

## Re: Prewarping Fc, Q or both

alright, there are a couple of different issues that may (or may not) need to be de-conflated. i'm gonna try to keep the number of symbols minimized. $$dB_\text{gain}$$...

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