I work with network devices that provide solutions to the telecom carriers and industries that work with data and wireless transmission. I have my own blog: www.behindthesciences.com

## Re: Extract a period from a unkown signal

wow! Thank you very much! That was a great work! Thank you so much for your explanations and analysis of the signal :) this is really interesting.

## Re: Extract a period from a unkown signal

are you plotting the .mat file? I'm afraid that there must be some kind of mistake in the .mat file, because the original file (the .wav file in the Dropbox link...

## Re: Extract a period from a unkown signal

wow! This is an awesome methodology! Thank you very much for this!Also, thanks a lot for selecting the cleanest bit of he signal, this was hard to me.Now I'm trying...

## Re: Extract a period from a unkown signal

if we name "y" the signal I uploaded, what I'm looking at is "y(:,1)", so I think this is th I data. Could you upload what you see, please?

## Re: Extract a period from a unkown signal

it's really tedious to extract a sine wave by zooming. They don't really look like sines waves:at least, they don't look like periodic waves

## Re: Extract a period from a unkown signal

Thank you, I understand now. However, now the challenge seems to be to extract those 100 clean samples. Unless I create a sine signal with the same sample frequency...

## Re: Extract a period from a unkown signal

hey! Yes... still working on this :)That sounds very good and it's something I definetively want to do! I tried the first part, but I'm not sure if this is correct. First,...

## Re: Extract a period from a unkown signal

Thank you very much! I put the signal here: https://www.dropbox.com/s/ijqs7xap7nwzhus/HDSDR_SH...

## Re: Extract a period from a unkown signal

that'd be great, thank you! Let me know which one of these would be more convenient:1. recorded IQ data in a .wav file (this would be the original recorded data)2....

## Re: Extract a period from a unkown signal

hey! thanks for this algorithm :)This is what happens when applied into my signal:...I think that's correct. There are similar patterns

## Re: Extract a period from a unkown signal

Oh, I see what you mean: I'd like to extract as much information as I can from my recorded signal. But it looks like this signal can be non-periodic or at least,...

## Re: Extract a period from a unkown signal

Hi David,thanks a lot for the algorithm and your explanation. My goal with this exercise is to clean my signal from noise and possible interference.I think with Goertzel...

## Re: Extract a period from a unkown signal

Hi again,in the Matlab function, the frequency index has to be an array but I'm not sure how to create it:There is an example in the Mathworks link I put before...

## Re: Extract a period from a unkown signal

Thanks a lot, I'm sorry to hear that you lost your first answer!I'll try this algorithm in Matlab with my signal and let you know how it goes :) Thank again!

## Re: Extract a period from a unkown signal

I had the same issue. Anyway, it works from this PC where I used to be logged in :)

## Re: Extract a period from a unkown signal

Thanks, David. This looks very useful. Just a question: I check that there is a function in Matlab that performs the filter https://es.mathworks.com/help/signal/ref/goertzel.html...

## Re: Extract a period from a unkown signal

Thank you!what sort of additional information should I provide?Also, when you say band-pass filtering, would you remove the spectrum around the peak highlighted...

## Re: Extract a period from a unkown signal

I'll do that. Thank you!

## Re: Extract a period from a unkown signal

thank you, but then "m" is going to be an array and I think it needs to be a scalar.Also, I realized my previous plot was wrong and I corrected so, when I computed...

## Re: Extract a period from a unkown signal

thank you. I can't use the FM demodulation because I don't know the frequency deviation of the signal...so according to what I mentioned in my question, if the period...

## Extract a period from a unkown signal

Hi everyone,I recorded a periodic signal and it has some noise:Visually inspecting, I saw that a pulse width is 0.0214s and the period is 0.0302s.Also, I counted...

## Re: Visualizing the spectrum of a 433 MHz433 MHz signal in MATLAB

oooh...I see what you mean! I plotted what you said and I think I start seeing something now.Well, the signal's got many samples (22991297 samples, when not taking...

## Re: Visualizing the spectrum of a 433 MHz433 MHz signal in MATLAB

Thank you! So the magnitude of the signal would be the previous one I plotted? I mean, this one:or you mean, I and Q separately? In that case, this is the magnitude...

## Re: Visualizing the spectrum of a 433 MHz433 MHz signal in MATLAB

thank you. That's also what I'm looking for. At the moment, I just know the signal seems to be a kind of OOK, based on these codes. Regarding to the bandwith, I'm...

## Re: Visualizing the spectrum of a 433 MHz433 MHz signal in MATLAB

Oh, I see... thank you. All that I wanted to do is recording a signal from my parking remote which carrier frequency is 433MHz (in Spain). I have the rtl2838 dongle...

## Re: Visualizing the spectrum of a 433 MHz433 MHz signal in MATLAB

Thank you very much! Yes, the sampling rate (Fs) is 3.2Msps and the bandwidth is a bit weird, because I selected in the HSDR sofware using this: so as shown in...

## Re: Visualizing the spectrum of a 433 MHz433 MHz signal in MATLAB

thank you very much! This is the frequency plot I get:and for the time domain, I used this code:[y,Fs] = audioread('HDSDR_SHORT_433920kHz_RF.wav',[5000000 10000000]); samples=0:1:5000000; t=samples/Fs; plot(t,y)and...

## Visualizing the spectrum of a 433 MHz433 MHz signal in MATLAB

I recorded a 433 MHz IQ signal with a SDR dongle as a .wav file and when I read it in #MATLAB, I see the following:This is the code:<code>[y,Fs] = audioread('HDSDR_SHORT_433920kHz_RF.wav',[5000000...

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