The SNR in wireless channel cannot be measured but it can be
“estimated”. One way to do that for constant envelope modulation such as
PSK is by measuring the variance in the received signal envelope.
Ideally you should receive a constant stable envelope of your signal.
However, due to the noise in the channel (assuming WGN channel, which is
normally the assumption for the famous theoretical waterfall plots for
BER vs SNR) you can find a relation between the variance in the envelope
To get the exact relation I suggest you to look at the last chapter of
Optical Bit Error Rate: An Estimation Methodology by
I hope that helps. Good luck!
[email@example.com] On Behalf Of Swapna
Sent: Thursday, February 12, 2009 8:57 AM
Subject: [Discuss-gnuradio] Measuring SNR
I am trying to implement a particular channel coding technique as part
of my work(Master’s Thesis). I need to test this technique in a fading
channel. But since I have no control over the channel I cannot quantify
channel condition.I need SNR to analyze the performance of the coding
technique.The only solution i thought was to inject noise at source and
ensure that transmission.But this is more like a simulation. I would
like to know if there are better ways to do this.
My second question is more related to Python programming. I need to run
a series of scripts one after the other in my work.Though these scripts
work fine independently. I get an error when I use os.popen(). In most
cases I do not want the control to return back to the calling
script.Could any one suggest what is the best way to do this, or atleast