find SNR of a noisy signal.

i have a noisy signal,can i just use this signal to calculate the snr?if so could somebody tell me what i should do?Thanks in advance

Answer 1

[Image Analyst]

You need to find the noise, and the signal. You can estimate them if you want, but to get the ratio you need each of them separately.

[yihui]

so how i estimate them?

[Image Analyst]

You can use conv() to smooth your signal with a box filter. But if you don't know your true signal then you won't know how much to smooth it. I guess you could just eyeball it and go with whatever you think looks good.

smoothedSignal = conv(noisySignal, ones(1, windowWidth)/windowWidth, 'same');