Hi, I'm new user of GNU. Can someone please help me in creating a flowgraph of AM transmitter. I have to use it for communication of radio having a range 3-30 MHz. Receiver part is already done. I just wanted a waveform of transmitter part only. I have to integrate this waveform with FM receiver. Please help.
on 2013-10-08 17:23
on 2013-10-08 19:45
First of all, I'm sorry that I could not understand clearly what you want. Are you using any hardware or you are just running a simulation using *GNU Radio*? What do you mean by waveform of transmitter? How do you integrate AM transmitter with FM receiver? If you have USRP and want DSBSC AM, it is easy to construct. Take a audio sample file. Connect it to USRP sink with appropriate interpolation. That can be counted as AM.
on 2013-10-09 10:10
Assuming you mean analog AM transmitter, you use a float-to-complex, connect a constant source with value of 1 to IM input. Then the audio source connects to RE input. You will need an adjustable attenuator on the complex output before going to the sink device. Using a multiply const with slider, adjust while monitoring the audio quality on AM receiver because it can easily overdrive. You could also have issue with DC offset (IQ calibration) on sink. In that case you would need to use a multiply block to offset frequency on baseband.