Hi Sinnadyr,
Thanks for feedback...
Currently we are using FM modulation to transmit the video signal through the 12V DC line using on semi LA72910V modulator and demodulator. It's works fine in the lab condition of 12V DC line. However, when we plug into the Car's DC line from the battery to the back light, it cannot function. Only able function in the short distance and still having distortion at the display unit. We are suspecting there is the DC line impedance that causing the problem.
As for now, we are looking for others solution if possible.
At first, we are looking at the digital modulation method. However find out if just using the normal video A/D from composite signal to digital, and convert it to serial, it will ends up with high frequency with above 400MHz. With frequency higher than 200MHz, the data will loss while it transmit in DC line.
It can be other solution where using the HD-PLC standards. However with this, we need to add in the more component as need to have the video decode and encoder. This will increase the cost of the project.
Do you have any idea or recommendation that can be shared out?