Radio/Gnuradio/Frequencies of Interest - Revision history

Admin: Admin moved page Gnuradio/Frequencies of Interest to Radio/Gnuradio/Frequencies of Interest

2016-05-22T15:52:20Z

Admin moved page Gnuradio/Frequencies of Interest to Radio/Gnuradio/Frequencies of Interest

← Older revision	Revision as of 15:52, 22 May 2016
(No difference)

Admin: /* FFT Sink */

2015-08-18T02:26:01Z

FFT Sink

← Older revision		Revision as of 02:26, 18 August 2015
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	[[Image:GnuradioDecimationSignalWaterfall.png\|500px]]		[[Image:GnuradioDecimationSignalWaterfall.png\|500px]]

			=Next Steps=

			Now that we've got the signal cleaned up and we can see it clearly, our next step is to demodulate the signal: [[Gnuradio/Fun with Modulation]]

	=References=		=References=

Admin: /* FFT Sink */

2015-08-18T02:25:00Z

FFT Sink

← Older revision		Revision as of 02:25, 18 August 2015
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	It's important to autoscale your FFT plot, otherwise you might not see a sensible result.		It's important to autoscale your FFT plot, otherwise you might not see a sensible result.

	You can also add a waterfall. Again, ti's important to autoscale the waterfall display as well, especially since we're dealing with such weak signals in this SDR Wav file:		You can also add a waterfall. Again, it's important to autoscale the waterfall display as well, especially since we're dealing with such weak signals in this SDR Wav file:

	[[Image:GnuradioDecimationSignalWaterfall.png\|500px]]		[[Image:GnuradioDecimationSignalWaterfall.png\|500px]]

Admin: /* FFT Sink */

2015-08-18T02:24:30Z

FFT Sink

← Older revision		Revision as of 02:24, 18 August 2015
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	It's important to autoscale your FFT plot, otherwise you might not see a sensible result.		It's important to autoscale your FFT plot, otherwise you might not see a sensible result.

			You can also add a waterfall. Again, ti's important to autoscale the waterfall display as well, especially since we're dealing with such weak signals in this SDR Wav file:

			[[Image:GnuradioDecimationSignalWaterfall.png\|500px]]

	=References=		=References=

Admin: /* FFT Sink */

2015-08-18T01:06:59Z

FFT Sink

← Older revision		Revision as of 01:06, 18 August 2015
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	[[Image:GnuradioDecimationSignal.png\|500px]]		[[Image:GnuradioDecimationSignal.png\|500px]]

			It's important to autoscale your FFT plot, otherwise you might not see a sensible result.

	=References=		=References=

Admin: /* Gnuradio Flowchart */

2015-08-18T01:06:36Z

Gnuradio Flowchart

← Older revision		Revision as of 01:06, 18 August 2015
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	Third, create a low-pass filter to pick our signal out of all the noise.		Third, create a low-pass filter to pick our signal out of all the noise.

	=Gnuradio Flowchart=		=The Gnuradio Flowchart=

	Here's what the final gnuradio flowchart looks like:		Here's what the final gnuradio flowchart looks like:
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	''IMPORTANT: If you don't see something sensible like the plot above, MAKE SURE YOU CLICK THE AUTOSCALE BUTTON!!! This makes a huge difference.''		''IMPORTANT: If you don't see something sensible like the plot above, MAKE SURE YOU CLICK THE AUTOSCALE BUTTON!!! This makes a huge difference.''

	==Center Frequency==		===Center Frequency===

	This is straightforward - by setting the center frequency to the center frequency variable, you ensure that the displayed frequency is correct.		This is straightforward - by setting the center frequency to the center frequency variable, you ensure that the displayed frequency is correct.

	==Low Pass Filter==		===Low Pass Filter===

	To apply a low-pass filter, you call a low-pass filter function using the "taps" variable slot:		To apply a low-pass filter, you call a low-pass filter function using the "taps" variable slot:
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	[[Image:GnuradioTapsLowPassFilter.png\|500px]]		[[Image:GnuradioTapsLowPassFilter.png\|500px]]


			==FFT Sink==

			Last but not least, you'll pipe everything into an FFT sink so you can take a look at the signal and make sure it is clean.

			[[Image:GnuradioDecimationSignal.png\|500px]]

	=References=		=References=

Admin: /* Decimation, or Narrowing the Signal */

2015-08-18T01:05:03Z

Decimation, or Narrowing the Signal

← Older revision		Revision as of 01:05, 18 August 2015
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	[[Image:GnuradioDecimation.png\|500px]]		[[Image:GnuradioDecimation.png\|500px]]

	~~here is~~ the ~~resulting~~ FFT ~~that shows~~ the width of the signal:		If you take a look at the signal through an FFT sink, you can see the width of the signal matches the width we chose:

	[[Image:GnuradioDecimationSignal.png\|500px]]		[[Image:GnuradioDecimationSignal.png\|500px]]

	IMPORTANT: If you don't see something sensible like the plot above, MAKE SURE YOU CLICK THE AUTOSCALE BUTTON!!! This makes a huge difference.		''IMPORTANT: If you don't see something sensible like the plot above, MAKE SURE YOU CLICK THE AUTOSCALE BUTTON!!! This makes a huge difference.''

	==Center Frequency==		==Center Frequency==

Admin: /* Decimation, or Narrowing the Signal */

2015-08-18T01:03:27Z

Decimation, or Narrowing the Signal

← Older revision		Revision as of 01:03, 18 August 2015
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	[[Image:GnuradioDecimationSignal.png\|500px]]		[[Image:GnuradioDecimationSignal.png\|500px]]

			IMPORTANT: If you don't see something sensible like the plot above, MAKE SURE YOU CLICK THE AUTOSCALE BUTTON!!! This makes a huge difference.

	==Center Frequency==		==Center Frequency==

Admin: /* Gnuradio Flowchart */

2015-08-18T01:02:36Z

Gnuradio Flowchart

@@ Line 18: / Line 18: @@
 =Gnuradio Flowchart=
 ==Wav File Source==
@@ Line 34: / Line 38: @@
 This is where we do all the hard work.
 ===Decimation, or Narrowing the Signal===
@@ Line 47: / Line 47: @@
 [[Image:GnuradioDecimation.png|500px]]
 =References=

Admin at 00:58, 18 August 2015

2015-08-18T00:58:05Z

@@ Line 1: / Line 1: @@
 In order to analyze and decode a signal, we need to be able to narrow in on the frequency of interest first. Let's walk through a gnuradio flowchart that will allow us to do that.
-=Using Prior Work=
+=How It Will Work=
 As with the [[Gnuradio/Wav to Waterfall]] flowchart, we're extracting sound data from a wav file, so we'll use the flowchart covered in that page as a starting point.