End of Questions - Chp. 1 and 2

Question 1

What is the basic structure of mobile communications.

Answer 1

1. Channel
2. RF Unit
3. Modem
4. Physical Layer
5. MAC
6. RLC
7. PDCP

Question 2

What are the main challenges of mobile communication systems?

Answer 2

1. Spectrum with regulations
2. Fading
3. Interference
4. Standards

Question 3

Name the different diversity types

Answer 3

1. Spatial
2. Polarisation
3. Time/Frequency
4. Path
5. Multiuser

Question 4

Explain the trade-off between reliability and throughput

Answer 4

Throughput is the amount of data that can be sent. Increasing the amount of redundancy bits have the effect of decreasing throughout.

Question 5

Explain the concept of duplexing

Answer 5

Multiple Rx and Tc can communicate with each other in both directions.

Question 6

Explain the difference between FDD and TDD

Answer 6

FDD; seperate in frequency-domain. Assign orthogonal resources in freuqency.

TDD; Seperation of UL and DL in time-domain. Assign orthogonal resources in time.

Question 7

Name and explain the different design types for cell networks

Answer 7

1. Triangular
2. Diamond
3. Hexagonal

Question 8

Explain the concept of co-channel interference and how to reduce it.

Answer 8

1. When both use the same frequency
2. Multi-user detection/Beamforming

Question 9

In HetNet/Overlay deployments, what is the coverage layer and throughput layer?

Question 10

Explain what are relay networks?