Polytechnic University, Dept. Electrical and Computer Engineering
EE4414 Multimedia Communication System II
Homework 2 (Analog Color TV Systems)
Y. Wang, et al. Video processing and communications, Chapter 1 (mainly Sec.1.1,1.2,1.4)
B. P. Lathi, Modern digital and analog communication systems, Chapter 4 (mainly QAQ and Sec.
4.6, beyond what you have read last time)
1. Suppose a color is represented by a RGB triplet of (100, 100, 100). What are the YIQ values?
Explain your result.
2. Suppose a color is represented by a YIQ triplet of (70,-32,-32). What are the RGB values?
3. What is the benefit of converting RGB values to YIQ (or any luminance+chrominance
representation) when transmitting a color signal?
4. Describe the QAM method used to multiplex the I and Q components together onto a color sub-
carrier frequency. Draw the modulation and demodulation block diagram.
5. What are the factors that one must consider when choosing the color sub-carrier frequency?
What is the sub-carrier frequency used in NTSC color standard?
6. Draw a block diagram for demultiplexing YIQ components from the composite video signal
(containing the baseband luminance signal and the QAM modulated I and Q). Explain each
7. Why are comb filters desired in separating luminance from chrominance than conventional
8. Draw the overall spectrum of a color TV signal (including Y, I, Q and audio) when modulated
over a carrier frequency.
9. How can a monochrome TV set automatically extract the luminance signal from a broadcasted
color TV signal?
10. Draw the block diagram of the NTSC color TV transmitter and receiver, and explain functions
of each component.
11. Describe why backward compatibility is important in technology development.