WBFM Receive: Difference between revisions

From GNU Radio
Jump to navigation Jump to search
No edit summary
 
(5 intermediate revisions by one other user not shown)
Line 10: Line 10:
== 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 FM broadcast uses 75 kHz
 
; 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 (US) or 50e-6 (Europe)


== Example Flowgraph ==
== 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.
Implementing an FM broadcast band receiver is really easy with the WBFM Receive Block.
 
[[File:Broadcast_FM_fg.png|800px]]


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

Latest revision as of 18:07, 22 August 2023

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 FM broadcast uses 75 kHz
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 (US) or 50e-6 (Europe)

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]