J
Jason Hsu
Guest
The traditional diode detector does not distinguish between broadband
noise and narrowband signals.
Is there a way to detect the overall broadband noise level? In this
coming semester, I will be working on an automatic noise cancelling
device for amateur radio. The input for the feedback network will be
provided by a circuit that responds to broadband noise but does not
respond to narrowband signals. I would prefer to monitor the noise at
the RF level (BEFORE the signals and noise reach the receiver), but it
would probably be easier and cheaper to monitor the audio noise.
The only idea I can think of is using an A/D converter to convert the
audio output of the receiver into discrete-time signals, using DSP to
convert these signals into a DFT, and then integrating over the DFT to
come up with the noise floor measurement. Of course, there needs to
be a way to take the absolute value of the discrete points.
Has anyone here done anything like this? I studied DSP last semester,
but we never touched a single DSP chip in the class. Using and
implementing DSP hardware is something I'll be picking up on my own.
Jason Hsu, AG4DG
usenet@@@@jasonhsu.com
noise and narrowband signals.
Is there a way to detect the overall broadband noise level? In this
coming semester, I will be working on an automatic noise cancelling
device for amateur radio. The input for the feedback network will be
provided by a circuit that responds to broadband noise but does not
respond to narrowband signals. I would prefer to monitor the noise at
the RF level (BEFORE the signals and noise reach the receiver), but it
would probably be easier and cheaper to monitor the audio noise.
The only idea I can think of is using an A/D converter to convert the
audio output of the receiver into discrete-time signals, using DSP to
convert these signals into a DFT, and then integrating over the DFT to
come up with the noise floor measurement. Of course, there needs to
be a way to take the absolute value of the discrete points.
Has anyone here done anything like this? I studied DSP last semester,
but we never touched a single DSP chip in the class. Using and
implementing DSP hardware is something I'll be picking up on my own.
Jason Hsu, AG4DG
usenet@@@@jasonhsu.com