AM Stereo flowgraph for GNURadio. Implementation of Motorola's C-QUAM standard for AM Stereo transmission in GNURadio. The flowgraph requires no extra dependancies.
- cquam.grc -- The main attraction. A GRC flowgraph of an AM Stereo transmitter per the C-QUAM standard.
- mw.sts (optional) -- Optimised preset for the Stereo Tool processor.
By default, the flowgraph (grc) uses an 2-channel audio input (in this case, a virtual Pulseaudio source/sink). You can replace this with a FIFO or file input like any other audio source.
Simply attaching the virtual device to the UHD or osmosdr block with proper parameters shold produce a valid signal for testing. The latest flowgraph is confirmed to work on an MCS-3050 AM Stereo reciever using a HackRF transciever.
You can listen to the WAV (I/Q) files generated by the flowgraph or transmit to an AM Stereo reciever. To decode C-QUAM on your PC however, you'll needs the non-free sodiraSDR (has a demo version). Select "AM Radio" from the dropdown, click "Debug", and select "Stereo (CQUAM)".