RadioBanter - View Single Post

February 24th 05, 09:14 AM

wrote:

Unless your considering baseband signal desired to be the 50khz
signal
then what you've done is created an image reject mixer with a 50khz
output and not an SSB detector. The image reject mixer case means
your signal is in the output passband at LO+ 50khz but not at
LO-50khz. You'd still have to repeat the process again to get from
50khz to recovered audio with a 50khz digitally derived LO and mixing
process. You can do that. In the end your doing something that
needs only to be done once. Look at EMDRF [Experimental Methods in
RF
design] doing SSB in DSP is coverd there.

Thanks for the ideas. I will try to acquire EMFRD and look for more
details.

I am not having an RF frontend, the samples I have are in a file
captured by someone else and they are centered around 50 khz. I am
doing the mixing again to baseband, so yes, I am unnecessarily doing it
twice instead of once, but since I have no access to hardware now, I
have no other option. I will verify the waveforms at various points
again and get back.

Thanks again for the helpful comments. It was a bit confusing for me
initially to work with the complex digitally downconverted samples. I
think a bit of confusion still persists. I will go through the whole
thing again.

Thanks
Ramakrishnan