Academic year 2013-14

Data Transmission and Encoding

Degree:	Code:	Type:
Bachelor's Degree in Computer Science	21459	Optional subject
Bachelor's Degree in Telematics Engineering	21729	Compulsory subject, 2nd year
Bachelor's Degree in Audiovisual Systems Engineering	21606	Compulsory subject, 2nd year

 

ECTS credits:

8

Workload:

200 hours

Trimester:

2nd and 3rd

 

Department:	Dept. of Information and Communication Technologies
Coordinator:	Gemma Piella
Teaching staff:	Gemma Piella, Òscar Cámara, Gonzalo Vázquez, Anna Carreras, Patricia García, Alexis Bagué, Seckin A. Yildirim, Jorge Hernández, Blanca Mayayo, Adrià Tauste, Noemí Carranza
Language:	Catalan (lectures, material), Spanish (lectures, seminars, labs ), English (material, bibliography, labs)
Timetable:
Building:	Communication campus - Poblenou

 

Introduction

Data transmission and Coding (DTC) is a mandatory subject of the second year of the following degrees carried out by Polytechnic School in the Universitat Pompeu Fabra: bachelor’s degree in Telematics Engineering and bachelor’s degree in Audiovisual Systems.

This subject has been designed using a methodology adapted to the new European Higher Education Area (EHEA), also known as the Bologna Process, which aims to focus the learning process on the student. The main objective of this design is to involve continuously the student in the development of the subject by continuing assessment and individual study as a complement to the lectures. The difficulty of this subject makes this continuous two-term work essential to assume the minimum required knowledge.

The main objective of Data Transmission and Coding (DTC) is introducing the fundamental concepts for analysis and design of a digital communications system, including the applied concepts of information theory to data compression and coding as well as coding and correction of errors that are introduced by the communication channel. Currently, digital communications systems are becoming indispensable to assume the increasing demand of quantity and quality in data communication. The main reason of that is the flexibility and the different options of data processing provided by digital transmission, unlike analog transmission. Thus, the explained knowledge in this subject is fundamental for future engineers related to telecommunications.

Taking into account the skills that have been taught in other subjects, with a close relationship with Communication Systems, Principles of Communication and Network and Services Protocols, the DTC theoretical content will focus mainly on the stages of coding, both source and channel coding, and digital bandbass and bandpass modulation and demodulation stages. In addition the basic concepts of some advanced modulations, which are used in such important areas such as mobile communications, will be introduced.

The theoretical elements are the basis of the lectures, but an equally important component in this subject is the problem solving, which is a big part of individual work of the student outside the classroom and it will be evaluated during seminar sessions. In addition, students are required to develop teamwork, information search and oral and written communication skills from different deliverables and group practical activities during the subject.

 

Prerequisites

The DTC subject is a part of the set of subjects related to the “signal and communication theory”, some of them imparted in the bachelor’s degree on Telematics such as Communication Systems (SDC), Network and Services Protocols (PXS) and Principles of Telecommunications (PT). Then, the objective of this set of subjects is to explain the main elements of a digital communication system (SCD).

DTC will give a brief review of some concepts that have already presented in subjects such as Principles of Telecommunication and Communication Systems (for example, about signals and systems, transmitters and receivers, noise, sampling and quantification). These concepts represent the basis on which students can make progress towards a deeper understanding of digital communications.

Finally, it is important to emphasize the relevance of two mathematical tools on the DTC subject, Fourier (including convolutions) and probability, which are introduced in the first year of the degree and are further developed in the subjects of Signals and Systems and Probability and Stochastic Processes. DTC is not a basic math subject for engineers, but it requires a high knowledge of the commonly used Fourier properties, differences and relation between time and frequency domains and the main axioms of probability. Being a subject that deals with many equations, the student will not be asked to memorize all of them, and the necessary ones will be provided in the different exams, except those that are continuously worked throughout the subject.

 

Associated competences

Transversal competences

Specific competences

Instrumental 1. Oral and written communication in native language 2. Ability of analysis and synthesis 3. Knowledge of a second language, in this case, English.  4. Problem solving  5. Skills in information management Interpersonal 6. Planning and organization of teamwork 7. Ability of criticism and self-criticism. Systemic 8. Ability to put knowledge into practice 9. Ability of planning own work 10. Continuous learning

1. Ability to use knowledge on mathematics, science and engineering. 2. Design and run experiments, as well as analyze and interpret the results. 3. Ability to design a system which is a part or component in the area of Information and Communication Technologies to achieve the required specifications. 4. Ability to identify, formulate and solve engineering problems. 5. Ability to use techniques and tools of the modern engineering that are necessary for the practice in engineering. 6. Design, create, exploit and manage network and the communication systems.

 

Assessment

The evaluation of DTC is designed around a continuous learning of the student by means of work and continuing assessment, as well as the continuous feedback by the teaching staff about each student’s work.

The avaluation items of the DTC subject are summarized in the following table, specifying the weight of each item in the final grades, minimun grade requirements to pass and which elements can be retken (in July's period of exams):

	ITEMS	WEIGHT	CAN BE RETAKEN
Written tests	Written tests (1st test: blocks 1,2; 2nd test: blocks 3,4; 3rd test: block 5; 4th test: blocks 6 i 7 ) (minum grade required >=5 in 5 out of 6 blocks, with >=4.0 in the remaining block)	60%	Yes
Written outputs	Short tests during seminars (minum grade required >=5 for the average of best three out of the four tests in each trimestre)	15%	No
Execution tests	Labs (30% of short tests + 70% of reports) (minum grade required >=5 for the average short tests and for the final grades of lab sessions)	25%	No

 

Four writting tests will be performed (in the middle of each trimestre and during the period of exams at the end of each trimestre) where knowledge acquired ni the subject will be evaluated. Each writting test will evaluate one or two blocks of the subject. The DTC design is modular, meaning that it is mandatory to pass (grade >=5.0) at least five out of the six blocks and have the remaining block with a grade >=4.0 to pass the whole subject. If any block is not passed, the student will have the possibility of retaking the failed blocks during the period of exams in July's call.

Prior to every seminar there will be a collection of problems published in Moodle so that students can individually work before the seminar session. These problems correspond to concepts and knowledge seen in lectures and put into practice in lab sessions. During the seminar students will be asked to individually solve a set of problems similar to the ones in the collection of problems that need to be prepared for the seminar. The evaluation of this activity cannot be retaken and accounts for a 15% of final grades. The average of the best three grades for these activities (out of the four possible per trimestre) must be >=5.0 in each trimestre in order to pass the subject

Labs of the DTC subject are composed of 8 sessions of 2 hours each. In these sessions, the students will use Matlab to solve typical problems and practical examples applying theoretical concepts seen in lectures. For the labs of the first trimestre, corresponding to modulation concepts, each group of students (1-2 persons) will be asked to choose a small image that will be used as the data to be transmitted and received in the design of a digital communication system. Along the labs the different phases of a DCS will be studied, from preparing the image to be transmitted (formatting, quantification) to studying the influence of channel characteristics (e.g. noise) when receiving (detecting) the image with enough quality or the different possibilities to modulate information. Similar to the seminar sessions, the students will be asked to solve a small test at the beginning of each lab with questions related to a previous study that will be published days before the lab session. The average of these small tests in labs will account for a 30% of lab grades and must be >=5.0 in order to pass lab sessions. The remaining 70% of lab grades will be based on reports delivered by the students including the solution of the exercises proposed at lab sessions. These reports must be individually delivered through Moodle, before 48 hours after the end of the lab session. Furthermore, every group of students will be asked to deliver work performed during the lab session, which will be used to validate what is reported 48 hours later. The final grades of labs must be >=5.0 in order to pass the DTC subject.

 

 

Contents

The design of the DTC subject is composed of six mandatory modules. These six modules follow a curricular and disciplinar logic, according to the typical scheme of a digital communication system

Modules

- Module 1. Introduction to digital communication
• Unit 1. Introduction to digital communication
• Unit 2. Formatting and digital bandbase transmission

- Module 2. Transmission and digital baseband demodulation
• Unit 3. Receiver structure
• Unit 4. Detection in channels with noise

1st written test (middle of 1st trimestre)

- Module 3. Transmission and digital bandpass demodulation

• Unit 5. Transmission and digital bandpass demodulation

• Unit 6. Modulacions avançades d’espectre estès

2nd written test (end of 2nd trimestre)

- Module 4. Source coding
• Unit 7. Source coding
• Unit 8. Entropy and mutual information

3rd written test (middle of 3rd trimestre)

- Module 5. Channel coding: channel characterization

• Unit 10. Channel of information
• Unit 11. Channel capacity

- Module 6. Channel coding: different types of codes
• Unit 12. Linear codes
• Unit 13. Cyclic codes
• Unit 14. Convolutional codes

4th written test (end of 3rd trimestre)

 

Organization and specifications of contents

Module 1. Introduction to digital communication

Concepts	Processes	Skills
1.  Diagram of digital communications system 2.  Analog system vs. Digital one 3.  Basic concepts of the analog and digital communications: sampling, quantification, and baseband transmission	1. Design of block diagram 2. Important information extraction and a summarize of a text 3. Solution of problems about sampling, quantification and baseband transmission	1. Reasoning and use of previous knowledge 2. Work in pairs 3. Specificity and succintness 4.Capacity of criticism related to the own and the others work 5. Active participation in lectures and seminar sessions

Module 2. Transmission and digital baseband demodulation

Concepts	Processes	Skills
1. Detection in channels with noise 2. Symbol error probabilities 3. Structure of the receiver and optimal filters 4. Signal space 3. Intersymbol interference (ISI) 4.Techniques to reduce ISI: shaping filters and equalization	1. Representation of signals in the signal space with or without Gram-Schmidt method 2. Simulation with software of the concepts of baseband and band-pass transmission 3. Important information extraction and summary of a technical text in English 4. Problem solving about concepts of baseband transmission 5. Computation of error probabilities 6. Design of shaping filters and equalization 7. Analysis of curves of error probabilities	1. Reasoning and use the previous knowledge 2. Work in pairs 3. Extract and summarize the most important concepts of a module 4.Reason out and analyze the problems before using the most mechanical methods 5. Put the theory into practice 6. Analysis of technical texts in English 7.Autoevaluation and self-criticism of the own work 8. Active participation in lectures and seminar session

Module 3. Transmission and digital bandpass demodulation

Concepts	Processes	Skills
1.Modulation / demodulation with carrier and detection 2.Diferent waveforms to modulation and coherent detection 3. Non coherent detection 4. BPSK and BFSK error probabilities 5. Error probabilities for non-binary modulations 6. Aims and limitations of a digital communications system 7. Planes of error probability and efficiency of bandwidth 8. Power and bandwith limited systems	1. Problem solving about concepts of band-pass transmission 2. Computation of error probabilities   3. Design of a digital communications systems, choosing the optimum option in different situations   4. Analysis of planes of error probability and efficiency of bandwidth   5. Solving problems about the design of a digital communications system	1. Reasoning and use the previous knowledge 2. Work in pairs 3. Extract and summarize the most important concepts of a module 4.Reason out and analyze the problems before using the most mechanical methods 5. Put the theory into practice 6. Analysis of technical texts in English 7.Autoevaluation and self-criticism of the own work 8. Active participation in lectures and seminar session

Module 4. Source coding

Concepts	Processes	Skills
1. Discrete and conditional probability 2. Information sources 3. Codes and coding schemes. Optimal codes. 4. Uniqueness and immediateness 5. Entropy 6. Source extension 7. Conditional entropy 8. Mutual information	1. Probability computation 2. Use of the basic properties of probability 3.  Description of information sources, codes and coding schemes 4. Classification of codes into univocal or instantaneous 5. Computation of average length and efficiency of codes  6. Use of Kraft’s inequality  7. Entropy and mutual information computation  8. Use of source extension	1. Reasoning and use the previous knowledge 2. Work in pairs 3. Extract and summarize the most important concepts of a module 4.Reason out and analyze the problems before using the most mechanical methods 5. Put the theory into practice 6. Active participation in lectures and seminar session

Module 5. Channel coding: channel characterization

Concepts	Processes	Skills
1. Channel of information 2. Distance between code words 3. Rules of decoding 4. Redundancy 5. Capacity of the channel	1. Computation of channel probability depending on input or output 2. Application of decision rules 3. Computation of transmission rates and of the capacity of the channel 4. Computation of error probability	1. Reasoning and use the previous knowledge 2. Extract and summarize the most important concepts of a module 3.Reason out and analyze the problems before using the most mechanical methods 4. Put the theory into practice 5. Active participation in lectures and seminar session

Module 6. Channel coding: different types of codes

 

Concepts	Processes	Skills
1.  Linear codes 2. Generator matrices, parity matrix and syndrome 3. Cyclic codes, geneative polynom 4. Convolutional codes and Viterbi algorithm	1. Design of generator and parity matrices, and generation of codes with these matrices 2. Decoding by generator syndrome computation and by standard matrix 3. Construction of cyclic codes and decoding 4. Construction of convolutional codes and decoding with Viterbi	1. Reasoning and use the previous knowledge 2. Work in pairs 3. Extract and summarize the most important concepts of a module 4.Reason out and analyze the problems before using the most mechanical methods 5. Put the theory into practice 6. Active participation in lectures and seminar session

 

Methodology

The main objective of the design of the DTC subject is to continuously involve the student in the development of the subject by continuous assessment and personal study as a complement to the lectures. The difficulty of this subject makes that this continuous work along these two trimestres is essential to acquire the minimum knowledge required.

The EHEA methodology involves a configuration of the learning cycle that divides the activities into in-person ones and not in-person ones, representing the first 35% of the total work load of the subject and, consequently, 65% of student work outside the classroom. There are three types of classes: lectures, seminars and lab sessions. The first ones are done with all students of the subject and represent 56% of the total (42 hours, 21 sessions of 2 hours per week), leaving 28% (16 hours, 8 sessions of two hours biweekly) of in-person sessions for seminars, where a small number of students and 22% for practical sessions (16 hours, 8 sessions of two hours, mostly biweekly).

 

Resources

Basic bibliography (paper and electronic support)

• B. Sklar, “Digital Communications” (2nd Edition), Prentice Hall, 2001.

• R. B. Wells, “Applied Coding and Information Theory for Engineers”, Prentice Hall, 1999

Complementary bibliography (paper and electronic support)

• S. Haykin, “Communication systems” systems” (4th Edition), John Wisley & Sons, 2001

• A.B. Carlson, “Communication systems” (4th Edition), McGraw-Hill,McGraw 2002

• J.G. Proakis, “Digital communications”, (4th Edition), McGraw-Hill, McGraw 2000

• A.A. Rodriguez y F.P. Gonzalez, “Comunicaciones Digitales”, Prentice Hall, 2007

• G. A. Jones and J.M Jones, “Information and Coding Theory”, Springer, 2005

• J. G. Casas ,“Introducción a la Teoría de Códigos, Teoría de la Información y Criptografía”, Univ. Nacional Autónoma de México

Didactic resources. Teaching material of the subject

- Slides corresponding to each lecture uploaded at Moodle

- Exercises, additional documents, web references, other material available at Moodle

Didactic resources. Materials and support tools

- Basics of Information Theory
o http://www.cs.cmu.edu/~dst/Tutorials/Info-Theory/
http://www.cs.cmu.edu/~dst/Tutorials/Info

- The Error Correcting Codes (ECC) Page:
o http://www.eccpage.com/

- Wikipedia: Category:Information theory
o http://en.wikipedia.org/wiki/Category:Information_theory

- Additional exercises
o http://www.cl.cam.ac.uk/teaching/2002/InfoTheory/Chapter2Exercises.pdf
o http://www.econ.upf.es/~lugosi/inf/infohw.pdf
o http://www.mth.msu.edu/~jhall/classes/codenotes/Linear.pdf