WBFM Receive: Difference between revisions

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== Parameters ==
== Parameters ==


; Quadrature Rate
; Channel Rate
: Input sample rate of complex baseband input. (float)
: Input sample rate of complex baseband input. (float)


; Audio Decimation
; Audio Decimation
: How much to decimate quad_rate to get to audio. (integer)
: How much to decimate Channel Rate to get to audio. (integer)
 
; Deviation
: FM modulation deviation. Standard broadcast FM uses 75kHz
 
; Audio Pass
: Low pass filter rolloff frequency
 
; Audio Stop
: Low pass filter cutoff frequency
 
; Gain
: Audio gain
 
; Tau
: Preemphasis time constant (float) - typically 75e-6


== Example Flowgraph ==
== Example Flowgraph ==
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Implementing an FM broadcast band receiver is really easy with the WBFM Receive Block.
Implementing an FM broadcast band receiver is really easy with the WBFM Receive Block.


[[File:Pluto_FM_fg.png|800px]]
[[File:Broadcast_FM_fg.png|800px]]


== Source Files ==
== Source Files ==

Revision as of 15:38, 20 August 2020

Hierarchical block for demodulating a broadcast FM signal.

The input is the downconverted complex baseband signal (gr_complex).

The output is the demodulated audio (float).

Compared to WBFM Receive PLL, this one does a simple mono demodulation with deemphasis

Parameters

Channel Rate
Input sample rate of complex baseband input. (float)
Audio Decimation
How much to decimate Channel Rate to get to audio. (integer)
Deviation
FM modulation deviation. Standard broadcast FM uses 75kHz
Audio Pass
Low pass filter rolloff frequency
Audio Stop
Low pass filter cutoff frequency
Gain
Audio gain
Tau
Preemphasis time constant (float) - typically 75e-6

Example Flowgraph

Implementing an FM broadcast band receiver is really easy with the WBFM Receive Block.

Broadcast FM fg.png

Source Files

Python files
[1]
Block definition
[2]