## Goertzel Algorithm

Started by in comp.dsp6 years ago 16 replies

Hello, I found various documents regarding the Goertzel Algorithm along with formulas, pseudocodes and Fortran implementations as a way for...

Hello, I found various documents regarding the Goertzel Algorithm along with formulas, pseudocodes and Fortran implementations as a way for performing a faster and more accurate DFT in real-time on a small number of samples. However what I don't get is that I can't find any example for the IDFT of the Goertzel algorithm. What is the trick to get the inverse computation out of using Goertzel ei...

## bandwidth of the Goertzel

Started by in comp.dsp14 years ago 3 replies

Say I set up my Goertzel algorithm to detect a 1000Hz tone. What happens if the tone coming in is 1020Hz?How about 1100Hz? Will I still get gain...

Say I set up my Goertzel algorithm to detect a 1000Hz tone. What happens if the tone coming in is 1020Hz?How about 1100Hz? Will I still get gain from my Goertzel detector? I guess my question is, what is the shape and bandwidth of the Goertzel when used as a tone detector? I'm guessing it has something to do with the amount of samples processed...is there a formula for this?

## More on Sliding Goertzel Correction

Started by in comp.dsp16 years ago 5 replies

As Rick showed in previous post, the normal Goertzel's v(4), is: v(4)=x(4)+a*x(3)+(a^2-1)*x(2)+(a^3-2*a)*x(1)+(a^4-3a^2+1)*x(0) the sliding...

As Rick showed in previous post, the normal Goertzel's v(4), is: v(4)=x(4)+a*x(3)+(a^2-1)*x(2)+(a^3-2*a)*x(1)+(a^4-3a^2+1)*x(0) the sliding Goertzel (SGA) for v'(5) is v'(5)= x(5)-x(0)-v(3)+a*v(4) or after a lot of algebra: v'(5)=x(5)+a*x(4)+(a^2-1)*x(3)+(a^3-2*a)*x(2)+(a^4-3a^2+1)*x(1)+(B-1)*x(0) where B=a^5-4a^3+3a If we assume that instead of subtracting x(0) in v'(5) we su...

## Sliding Goertzel of Jacobsen&Lions correct?

Started by in comp.dsp16 years ago 16 replies

In Eric Jacobsen and Richard Lyons excellent article in the IEEE Signal Processing Magazine March 2003 issue entitled "The Sliding DFT" they...

In Eric Jacobsen and Richard Lyons excellent article in the IEEE Signal Processing Magazine March 2003 issue entitled "The Sliding DFT" they presented a sliding Goertzel (SG) algorithms on p78 eq 12 and Figure 8. From Figure 8 the SG is v(n)=x(n)-x(n-N) -v(n-2)+a*v(n-1) where a=2cos(2PI*k/N) If we performed the Goertzel on 4 data points. using the Goertzel formula v(n)=x(n)-v(n-2)...

Started by in comp.dsp14 years ago 1 reply

hi friends, i am using GOERTZEL algorithm for single tone detection but the problem is that it takes 80ms for single output i want to...

hi friends, i am using GOERTZEL algorithm for single tone detection but the problem is that it takes 80ms for single output i want to minimise its input sample can anybody tell me is sliding GOERTZEL is a solution for this? currently N = 240, Fs = 3000 F = 217 k = 17 thanks

## DTMF Detection using Goertzel

Started by in comp.dsp11 years ago 7 replies

Hello, I am implementing DTMF detection using Goertzel Algorithm.I have two questions 1.Since the duration of DTMF signal present is 40 msec...

Hello, I am implementing DTMF detection using Goertzel Algorithm.I have two questions 1.Since the duration of DTMF signal present is 40 msec and Goertzel takes 25msec should I detect the energy of incoming signal (at 3Khz) and then start Goertzel.(If I start my Goertzel after 20msec of actual signal I need another 5 msec more DTMF signal presence.But valid DTMF is available only for 20 msec....

## Goertzel Algorithm in Hardware

Started by in comp.dsp16 years ago 3 replies

Does anyone know how well a Goertzel implementation vs an FFT algorithm implemented in physical hardware, like an FPGA? Anyone have any...

Does anyone know how well a Goertzel implementation vs an FFT algorithm implemented in physical hardware, like an FPGA? Anyone have any benchmarks, etc? I looked at results I generated in Matlab, and the Goertzel algorithm seems to be calculated more readily than the FFT, but I am not an embedded programmer, so I don't know much about how well it would perform coded in VHDL etc.. I did do ...

## Spurious Goertzel Response to Input Change

Started by in comp.dsp12 years ago 6 replies

I have been using the Goertzel to pick out two different frequencies from a fairly noisy signal (testing using sine tones for now). The response...

I have been using the Goertzel to pick out two different frequencies from a fairly noisy signal (testing using sine tones for now). The response time is also very critical in my application and I have been working to compromise between the computing power available (an embedded DSP), time required to gather samples, and frequency accuracy. I think I've reached a sweet spot where Goertzel output ...

## Goertzel Algorithm

Started by in comp.dsp12 years ago 7 replies

I have recently read about the Goertzel algorithm and I am looking to use it in a FPGA/DSP. The problem is I am interested in using...

I have recently read about the Goertzel algorithm and I am looking to use it in a FPGA/DSP. The problem is I am interested in using the algorithm to compute about 1000 frequency bins during a microsecond period, so I am very interested in its performance in hardware to help me select a device. Does anyone know where I can find some info on the performance of the Goertzel algorithm in an FPG...

## Similarity between Goertzel filter and bandpass filter

Started by in comp.dsp8 years ago 5 replies

Hi, It was pointed out to me in another thread that a Goertzel filter is pretty much a very narrow bandpass filter that is run for a finite...

Hi, It was pointed out to me in another thread that a Goertzel filter is pretty much a very narrow bandpass filter that is run for a finite amount of time. This does make sense after looking more closely at the math. However, the neat thing about Goertzel is that the output is directly the coefficient of the wanted DFT bin. The 'power' or 'amplitude' of the tone can even be obtained without do...

## DTMF Detection

Started by in comp.dsp14 years ago 6 replies

Hi all. I?m trying to implement the goertzel algorithm in C#, but without good results. The steps I'm trying are: 1) I perform a goertzel...

Hi all. I?m trying to implement the goertzel algorithm in C#, but without good results. The steps I'm trying are: 1) I perform a goertzel for each of the frequencies in the table (lows and highs). For Low ones I use N=212 and 106 for High ones. 2) Save the highest ones (Low and High) 3) Then I perform 4 more goertzel for Low Freq (+/-)1.5%(+/-)2Hz and the same for High ones, to verify 2n...

Started by in comp.dsp9 years ago 9 replies

I am doing tone detection of 4 known frequencies using the Goertzel algorithm. The tones have a large bandwidth that I must be able to...

I am doing tone detection of 4 known frequencies using the Goertzel algorithm. The tones have a large bandwidth that I must be able to detect them, up to +/-4% of the tone value. To do this the Goertzel is set up to have large bin width, which makes the SNR not so good. Is there perhaps another approach that will have similar computation time as the Goertzel, but allow for better SNR? Thanks. ...

## Goertzel algorithm's amplitude shown in DSP

Started by in comp.dsp6 years ago 1 reply

Hello, Elwiz I am a master student of EE in NSYSU, Taiwan. I have a problem which the same as the past massage "Goertzel algorithm - elwiz -...

Hello, Elwiz I am a master student of EE in NSYSU, Taiwan. I have a problem which the same as the past massage "Goertzel algorithm - elwiz - 2005-10-25 12:49:00" in your website. I use the Goertzel filter to catch 2nd harmonic current written in DSP28335. And all the results of the 2nd value are proportionally matching the gain of N/2, i.e., for example, the input current is 0.5A(peak) a...

## Sliding Goertzel References

Started by in comp.dsp16 years ago 5 replies

Besides Eric Jacobsen and Richard Lyons excellent article in the IEEE Signal Processing Magazine March 2003 issue entitled "The Sliding DFT" here...

Besides Eric Jacobsen and Richard Lyons excellent article in the IEEE Signal Processing Magazine March 2003 issue entitled "The Sliding DFT" here are two Sliding Goertzel papers. (Unfortunately they are not free. Hope your Library has them or the pdf download will cost you 30 bucks!) (1) Joe F. Chicharo, Mehdi T. Kilani, "A Sliding Goertzel Algorithm" , Signal Processing, Vol 52, 1996 p283...

## frequency detection (goertzel) - comparing detected tone energy vs. total signal energy

Started by in comp.dsp12 years ago 5 replies

hi, i'm trying to implement the goertzel algorithm to detect a small number of frequencies in an audio signal (16-bit, 8kHz). i'm using the...

hi, i'm trying to implement the goertzel algorithm to detect a small number of frequencies in an audio signal (16-bit, 8kHz). i'm using the approach/code outlined in this article: http://www.embedded.com/story/OEG20020819S0057 i've seen a post on comp.dsp which suggests to compare the sum of squares of the samples for the block used in the goertzel iteration and compare it to the ener...

## Goertzel Algorithm using undersampling ?

Started by in comp.dsp5 years ago 2 replies

Hi guys, I have recently read an great article about Goertzel Algorithm...

Hi guys, I have recently read an great article about Goertzel Algorithm at https://courses.cs.washington.edu/courses/cse466/12au/calendar/Goertzel-EETimes.pdf I thought you could help me a bit now. I'm building laser rangefinder which use FFT to calculate distance. Firstly I thought I need to implement FFT in code and then look for highest bin in the spectrum to calculate it's phase ( will hav...

## Goertzel was named after who?

Started by in comp.dsp14 years ago 23 replies

For some reason I am really wondering who the Goertzel algorithm was named after. Does anyone have an idea?

For some reason I am really wondering who the Goertzel algorithm was named after. Does anyone have an idea?

## Is the usual Goertzel algorithm wrong?

Started by in comp.dsp14 years ago 2 replies

Hi, I"ve been trying to figure the Goertzel algorithm out and I am at a point where the maths just doesn't seem to work out right: For...

Hi, I"ve been trying to figure the Goertzel algorithm out and I am at a point where the maths just doesn't seem to work out right: For example, referring to http://cnx.rice.edu/content/m12024/latest/ There is the following claim: X(k) = y(N) (1) However, this is obviously FALSE because from the definition of X(k) there is NO x(N) term while the difference equ...

## DTMF detection with Goertzel

Started by in comp.dsp14 years ago 36 replies

Hello, I am wondering what would be the smallest number of sample that one can use with Goertzel algorithm to detect DTFM. Assuming...

Hello, I am wondering what would be the smallest number of sample that one can use with Goertzel algorithm to detect DTFM. Assuming 8Ksps. Can I use 40 samples? Can I use 160 samples? Should it be an even number? What is the restriction on this matter? Best regards

## Goertzel Algorithm

Started by in comp.dsp14 years ago 2 replies

Goertzel's Algorithm was recommended in a previous topic. I've found some C code that will get me going really quickly. I was...

Goertzel's Algorithm was recommended in a previous topic. I've found some C code that will get me going really quickly. I was wondering whether the samples have to be centered around zero? Or can they be used directly from an ADC (i.e. range from 0 to 255 or so and be centered about 128?) Thanks, John