Is it possible to find the amount of noise or SNR of a signal from its time series output? For example; let
x = randn(100,1) and
y = awgn(signal,-5,'measured'); be two signals. Here
signal is an unknown source signal of length 10,000 data points.
In Matlab this is what I did:
snr(x) = 0.5177 and
snr(y) = -34.3797 dB Shouldn't I get
-5 dB as SNR?
I am unable to understand what these values convey as they are a ratio: How is 0.5177 coming? Since I am generating
y with an SNR of -5 dB, so
snr(y) should be -5 dB. Please help in clarifying if these answers are right and how to make sense of it.