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Basic SNR question

Started by usu_vlsi October 2, 2008
Hi,

I am kind of new to Signal Processing. I have two questions

1. I have a signal source, a in the lab, for eg. a 20kHz sine wave
generator. I connect it to a spectrum analyzer. I can see the
frequency spectrum of the signal. Can somebody explain to me how I can
calculate the Signal to Noise ratio from the spectrum analyzer. I have
no way of sampling the 20kHZ sine wave, the signal generator, and the
spectrum analyzer are the only equipment I have (ofcourse I have a PC
with Matlab on it)

2. I have the same 20kHz signal sampled at some frequency, say 8Mz. I
have the sampled data in an array. I calculated FFT of some 1 million
samples, after applying the blackman window function. Now how do I
calculate the SNR of the signal?
Check out http://www.elisanet.fi/~d635415/webroot/SNR3/index.html for a
discussion of SNR measurement with a Spec An.

thanks
On Thu, Oct 2, 2008 at 5:28 PM, usu_vlsi wrote:

> Hi,
>
> I am kind of new to Signal Processing. I have two questions
>
> 1. I have a signal source, a in the lab, for eg. a 20kHz sine wave
> generator. I connect it to a spectrum analyzer. I can see the
> frequency spectrum of the signal. Can somebody explain to me how I can
> calculate the Signal to Noise ratio from the spectrum analyzer. I have
> no way of sampling the 20kHZ sine wave, the signal generator, and the
> spectrum analyzer are the only equipment I have (ofcourse I have a PC
> with Matlab on it)
>
> 2. I have the same 20kHz signal sampled at some frequency, say 8Mz. I
> have the sampled data in an array. I calculated FFT of some 1 million
> samples, after applying the blackman window function. Now how do I
> calculate the SNR of the signal?
>