Hi,
I'm new to gnu radio and I'm trying to demodulate a 125kpbs ASK signal from a device I have, as a first project. I'm using RTL-SDR as the input device.
I'm slowly getting there. I receive the signal, at 2Msample/s, I low-pass filter it to 300khz, I send it through the AM demodulation block and then through the DC blocker.
From there I have my signal and it looks fine i.e I could retrieve the information manually by looking at it.
Now I think the goal is to somehow synchronize with the bits and re-sample to get 1 sample per bit. This could then be sent to a file. Is that it?
At first glance I'm thinking I should have a PLL which ouputs a clock at about 250khz (twice the bit rate) and synchronize the rising edge with every bit transitioning from 0 to 1 so unless I receive only ones ou zeros I should be quite in sync. Then I could toggle a sample every falling edge of the clock which should be at about the middle of the bit.
Is this a viable solution? Can it be done with gnuradio? Other alternatives?
Thanks