By testing the system using ON/OFF keying, a clear
restored video stream without noise and with a transmission
rate of 10Mbps is captured. It is worth mentioning that this data
rate without using the blue filter is 6Mbps. The link range is
about 1m with the commercial photodetector (APD110A2).
With pulse amplitude modulation using our 4x4 LED array, the
transmission rate increase to 40Mbps. Overcoming the
background noise is achieved by adding a software processing
procedure after the ADC at the Receiver. Both the original
restored waveform and modified restored data after software
processing are compared and shown in Figure 7 to illustrate the
result.