I am building a communication system which uses light. For the system, I've buiult a custom analog circuit and connected it to LFRX with SMA-BNC-Alligator clip.
A simple dry run gives the following:
As you can see, data is transmitted with on off keying.
(Please ignore some ripples and fluctuation, it's due to 60 Hz fluorscent light interference. I'll fix it later.)
I wonder that such input range (+- 50 mV) is quite acceptable for GNU Radio to manipulate.
Since it's my first time to physically implement a communication system, I only have mathematical and theoretical knowledge, but have little experience and sense about dBm, rx sensitivity and so.
But as I can see the waveform not so bad, I think I can manipulate it by equalizing or something...
PS: In addition, that 60 Hz interference, would it be better if I filter out that at the analog circuit with high pass filter? Or is it just ok to use high pass filter block in GNU Radio. I think the former is better to reduce the computational cost of GNU Radio. And it is more proper to filter out before it passes through the ADC...
Regards,
Jeon.