Difference between revisions of "Power Squelch"

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Gate or zero output when input power below threshold
 
Gate or zero output when input power below threshold
  
This is a basic template. Please improve it.
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This will either pass the input unchanged or block it, depending on whether its envelope is over a certain threshold. The envelope is calculated by taking the squared magnitude of the signal and lowpassing it with a single pole IIR filter (with the specified alpha). 
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The ramp parameter specifies the attack / release time, in samples.  A sinusodial ramp is used to progressively mute / unmute the input.  If ramp is set to 0, input is muted / unmuted without a ramp.
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If the gate parameter is true no output will be produced when in muted state, instead of producing zeros (the default).
  
 
== Parameters ==
 
== Parameters ==
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; Threshold (''R'')
 
; Threshold (''R'')
 
: Threshold (in dB) for power squelch
 
: Threshold (in dB) for power squelch
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; Alpha (''R'')
 
; Alpha (''R'')
 
: Gain of averaging filter. Defaults to 0.0001.
 
: Gain of averaging filter. Defaults to 0.0001.
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; Ramp  
 
; Ramp  
 
: Sets response characteristic. Defaults to 0.
 
: Sets response characteristic. Defaults to 0.
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; Gate  
 
; Gate  
 
: If true, no output if no squelch tone. if false, output 0's if no squelch tone (default).
 
: If true, no output if no squelch tone. if false, output 0's if no squelch tone (default).

Revision as of 15:15, 22 July 2019

Gate or zero output when input power below threshold

This will either pass the input unchanged or block it, depending on whether its envelope is over a certain threshold. The envelope is calculated by taking the squared magnitude of the signal and lowpassing it with a single pole IIR filter (with the specified alpha).

The ramp parameter specifies the attack / release time, in samples. A sinusodial ramp is used to progressively mute / unmute the input. If ramp is set to 0, input is muted / unmuted without a ramp.

If the gate parameter is true no output will be produced when in muted state, instead of producing zeros (the default).

Parameters

(R): Run-time adjustable

Threshold (R)
Threshold (in dB) for power squelch
Alpha (R)
Gain of averaging filter. Defaults to 0.0001.
Ramp
Sets response characteristic. Defaults to 0.
Gate
If true, no output if no squelch tone. if false, output 0's if no squelch tone (default).

Example Flowgraph

Insert description of flowgraph here, then show a screenshot of the flowgraph and the output if there is an interesting GUI. Currently we have no standard method of uploading the actual flowgraph to the wiki or git repo, unfortunately. The plan is to have an example flowgraph showing how the block might be used, for every block, and the flowgraphs will live in the git repo.

Source Files

C++ files
TODO
Header files
TODO
Public header files
TODO
Block definition
TODO