Q1. Consider a VLC (Visual Light Communication) system. In which LED is used as a Transmitter to send
the information and PD (Photo Detector) is used as a Receiver to decode the signal. Suppose you insert
a slowly varying information signal V(t) that is a voltage signal to the LED, which produces a time
varying light signal P(t). If the light signal is propagated through an ideal channel with no noise, it
produce a voltage signal at the PD VPD(t)= 3.5sin(20t + π/2).
1. Draw the important block diagram of the communication system.
2. Sketch or Label the IP/OP signals in the diagram.
3. Draw VPD(t)
4. Suppose that channel has an ambient light (Noise) which generated by another light source.
That noise is generated 1V DC voltage at the PD.It is a Noise and additive to the desired
signal.
Draw the block diagram of the new communication systems and Sketch or Label the IP/OP
signals in the diagram.
5. Draw VPD(t) with the additive noise.
6. Propose a method to eliminate this ambient light noise.
