Wireless Communications
Objectives
The main goal it is to give to the students the necessary skills to understand and to establish connection between the following aspects:
Cellular planning
Concepts of frequency planning associated to cellular networks. Frequency planning. Frequency re-use strategies and capacity maximization techniques. The RF interference problem in cellular systems.
Propagation aspects
Propagation constrains related with coverage planning, as ground reflection and obstacle diffraction. Knowledge of the different propagation models normally adopted in the project of mobile communications systems. Channel characterization and effects. Diversity techniques used for fading compensation, due to propagation multi-path.
Transmission in mobile communications
Understanding the modulation techniques adopted on mobile communications and the limitations. Understand the advantages and characteristics that justify the choice of one modulation in a mobile communication system. Spectral limitations and power amplification problems, associated to the digital modulations normally adopted. Identify the necessity of detection and correction codes and the applicability context of each one.
Systems
System analysis including GSM, UMTS and LTE, topology and constitution. Access and encryption techniques. Protocol analisys. Codification structures. Services.
General characterization
Code
7303
Credits
6.0
Responsible teacher
Paulo da Costa Luís da Fonseca Pinto, Paulo Miguel de Araújo Borges Montezuma de Carvalho
Hours
Weekly - 4
Total - 56
Teaching language
Português
Prerequisites
The students must be comfortable with complex and integral calculus and C++ programming techniques. It is also necessary previous attendance, with success, on Introduction to the Telecommunications and Telecommunications Systems.
Bibliography
“Wireless Communications, Principles & Practice”, Theodore S. Rappaport, Prentice Hall Communications Engineering and emerging Technologies Series, 1999.
“UMTS Networks Architecture, Mobility and services”, Heikki kaaranen, Ari Ahtiainen, Laurie Laitinen and Vlterri Niemi, John wiley and Sons, 2001
“GSM Switching, Services and Protocols”, Jörg Eberspächer, Hans- Jörg Vögel e Christian Bettstetter, John Wiley & Sons, 2001.
Additional bibliography
Communications systems, A. Bruce Carlson, McGraw-Hill, 2001.
Teaching method
Evaluation method
General Rule
The assessment is composed by a theoretical part and a laboratorial part.The student must have a minimum of 9.5 point in each part
The final grade for the approved students (in any of the possible dates of exams) is weighted in 75% for the theoretical part and 25% for the laboratorial part
Theoretical Part
The assessment of the theoretical part can be distributed or centralized:
Distributed assessment – consists on the execution of two mid-term tests. On the date of the final exam it is possible to repeat one mid-term test upon invitation from the structors. The theoretical grade is calculated using the following formula:
theor_grade = 37.5% 1st test + 37.5% 2nd test
Centralized assessment – consists on the execution of a final exam. In this case the theoretical grade is the grade of the exam. Students that opted by the distributed assessment can change to the centralized assessment any time during the semester.
Subject matter
1. Introduction
1.1. Evolution of the mobile communications
1.2. Typical architecture
1.3. Private mobile radio systems
2. Basic concepts in the cellular planning
2.1. Frequency re-use
2.2. Strategies for channel attribution
2.3. Handoff methods
2.4. Interference
2.5. Techniques for capacity improvement
3. Propagation aspects
3.1. Propagation models
3.2. Multi-path
3.3. Slow and fast fading
4. Transmission in mobile communications
4.1. Basic concepts
4.2. Digital modulations
QPSK and O-QPSK
GMSK
MQAM
Emission and reception structures
4.3. Channel codification
Block codes
Convolutional codes
4.4. Direct spreading codes
Principles and characteristics
Acquisition and tracking and time synchronization
Receivers’ structures
5. Systems/applications
5.1. System GSM (Global System will be Mobile Communications)
GSM and DCS 1800
Topology and components of GSM network
Channel types
Multiple access techniques (FDMA/TDMA)
GSM frame structure
Handover and rooming procedures
Establishment and guiding of calls
Logical structure
5.2. UMTS (Universal Mobile Telecommunications System)
5.2.1. Evolution to mobile communications systems of 3rd generation
5.2.2. UMTS technology
5.2.3. Overall physical layer (L1) function
Description of codes used in UMTS for synchronisation, channelization and scrambling
Application of the codes
Description of physical channels and mapping between physical and transport channels
Physical channel timing, slot and frame structures
Synchronisation arrangements and procedures
Pilot channels: common and channel associated
Channel coding and multiplexing
Differences between FDD and TDD mode at the physical layer
5.2.4 Logical Layer
5.2.4.1 Radio link control (RLC)
Error protection and error free data transmission
Segmentation / reassembly
Flow control
5.2.4.2 Medium access control (MAC)
Channel multiplexing
Multiplex different flows of the same user onto the same dedicated transport channel
Multiplex flows of several users onto a shared transport channel
Packet scheduling / priority control
5.2.4.3 Packet data convergence protocol (PDCP)
Enabling the independence of L3 and lower layers
Adaptations to facilitate IP on L3 (for PS domain)
Independent development of lower layers and L3
5.2.4 Broadcast and Multicast Control (BMC)
5.2.5 Procedures
Idle mode procedures
Connected mode procedure
Handover
Location services (LCS)
5.4. LTE
5.4.1. Introduction to LTE
5.4.2. General technology characteristics
5.4.3. Physical Layer
5.4.4. Integration with other mobile communications systems