| Summary: | 碩士 === 國立中央大學 === 光電科學研究所碩士在職專班 === 96 === In this study, we considered the communication characteristics ofan NTSC imaging signal in free space by light transmission. Toaccomplish this purpose we used an LED and a photodiode as thetransmitter and the receiver, respectively.
The amplitude of the signal was modulated in our system and thelow frequency background noise isolated by an electrical filter. Thechoice of a visible-light LED as our light source made it easy to checkif signal transmission had stopped, however this could be replaced byan infrared LED, in which case we could extend the communicationdistance by enhancing the power of the LED.
In addition, we also used an auto-gain amplifier to adjust thesignal of the post-circuit, to keep it within an acceptable range. Thisalso expanded the range of the received signal. In our experiments thecommunication distance was about 1 meter.
|
|---|
