WBFM Receive

From GNU Radio
Jump to navigation Jump to search

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


Channel Rate
Input sample rate of complex baseband input. (float)
Audio Decimation
How much to decimate Channel Rate to get to audio. (integer)
FM modulation deviation. Standard FM broadcast uses 75 kHz
Audio Pass
Low pass filter rolloff frequency
Audio Stop
Low pass filter cutoff frequency
Audio gain
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
Block definition