Re: [Discuss-gnuradio] Gaining RSSI, SNR, CNR or BER information

[Bastian Preindl]

Dear Jonathan,

> If you use the USRP, you will obtain a complex baseband representation
> of your satellite signal.  From this, you will need to implement a
> demodulator for the particular signal involved.  From the output of
>   

As far as I know there already exist demodulators for (A)FSK, BPSK and 
MSK - which covers the majority of the small satellites we focus on.

> the demodulator, there are several ways to estimate signal-to-noise
> ratio that do not require prior knowledge of the bit pattern.  From
> the signal-to-noise ratio, you can estimate the theoretical bit error
> rate for the type of modulation in use.  See:
>
> http://www.comsoc.org/comm/private/2000/oct/1681_48comm10-pauluzzi.html
>
> GNU Radio is very suitable for this sort of thing

That are very good news for me! I'm aware about the relations between 
SNR and BER - I just wonder about the several ways to estimate the SNR 
in GnuRadio. That's exactly the information I lack of - do you have any 
documentation/examples/sources for how to accomplish that?

And what about the usage of sound cards as ADC? Can I also obtain SNR 
information when I just have an audio stream as source?

Many thanks and best regards

Bastian