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Re: Digital Equalizer Design for a Radio Receiver

Started by Anonymous February 8, 2006
I was thinking of something like:

http://www.w9gr.com/

"Anonymous" <someone@microsoft.com> wrote in message news:...
> > "Mark" <makolber@yahoo.com> wrote in message > news:1139417980.646987.93170@g44g2000cwa.googlegroups.com... > > Clark, > > > > The AF (adaptive filter) you are describing automatically adapts the > > overall bandwidth of the signal...OK...good... but does it actually > > compensate for selective fading the way an adaptive equalizer does for > > digtial modulation... i.e. if the selective fading causes a 5 dB tilt > > across the channel, will your AF compensate for that tilt by creating > > a reverse tilt or will it just reduce the bandwidth because the SNR is > > poor.... > > > > Mark > > > > An AF needs some known component or statistic by which to generate an
error
> term from. With voice AM there really isn't any fixed parameter to lean
on.
> A loss of amplitude could be fading on the RF OR the person speaking could > have just stopped talking. If it were FM you could probably uses the > constant envelope of the signal, but I don't see any way to do it with AM. > > Maybe ALC on the audio will work for you I just know that an AF in the > predictive mode worked well for us in the past to make HF audio much more > tolerable to listen to. > > There used to be several companies selling little dsp boxes that you hung > off your radio speaker to do this. I can recall a name right now. > > -Clark > >