Week 3 - Transmission of Digital Signals

Question 1

What is baseband transmission?

Answer 1

Uses a lowpass channel (lowest frequency 0)

Digital signal is not converted to analog

Entire transmission medium used by one channel (preserving shape of digital signal requires infinite bandwidth)

Question 2

What is broadband transmission?

Answer 2

Uses a bandpass channel (lowest frequency non-zero)

Digital signal converted to analog (modulation)

Question 3

How does SNR change with less noise and more noise

Answer 3

High SNR little noise
Low SNR noisy

Question 4

What 3 factors does data rate depend on?

Answer 4

Bandwidth
Noise
# Levels

Question 5

What are the two meanings of bandwidth in different contexts?

Answer 5

1. Difference between min and max frequency
2. Bit rate

NOTE: Increasing one will increase the other.

Question 6

What is the bandwidth delay product?

Answer 6

The number of bits that can fill a link. It is TWICE the bandwidth * delay (full-duplex)

2 * BW * delay

Question 7

What are the two transmission modes, which one is faster?

Answer 7

Parallel and serial, parallel is faster by a factor of n.