Hello Mostafa,
On 12/29/2014 12:55 PM, Mostafa
Alizadeh wrote:
I finally got to this point that if one need to
measure SNR, it means that he/she has to eliminate all the other
channel effects as well as receiver uncertainties, (like fading,
shadowing, Doppler shift, carrier frequency and phase offsets
etc.) to have a correct estimate of SNR.
SNR is relative to signal. Signal is what you define it to be. You
can say "I measure my SNR after equalizing and perfect
synchronization", you could also say "the power of the signal coming
out of the receiver amplifier relative to the noise generated in
that amplifier, before any filtering". It's all up to your
definition. I will never cease to repeat that.
There is no physical entity SNR to measure. When you say "SNR is XY
dB", it is utterly meaningless unless you define what your signal is
and where in your signal processing chain you determine the SNR.
Otherwise, he/she coudln't obtain signal-to-noise
power ratio.
Remember the received signal formulation I mentioned
before:
y(t) = h(t) * x(t) + n(t).
Thank you all. Any interesting
ideas would be appreciated.
... you're still asking for easy ideas how to solve your problem
which is complicated. You will have to accept the fact that SNR is
not a universal measure with a "right" way to measure for any kind
of signal, any kind of channel, any kind of system.
Marcus
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