Description

The course "Signal Transmission and Reception Techniques" is an introduction to the different existing methods for the exchange of information at the physical layer level. Its main focus is on pulse amplitude modulation (PAM) as illustrative example. The main components of a digital transmitter and receiver are described, as well as the different effects caused by the communication channel and the different performance parameters of a digital system.

English Friendly subject: International students may request from the teachers: a) resources and bibliographic references in English, b) tutoring sessions in English, c) exams and assessments in English.

Requirements

Subjects recommended to have taken before

• Physics: Analysis of Linear Circuits (V05G301V01108)
• Mathematics: Probability and Statistics (V05G301V01107)
• Digital Signal Processing (V05G301V01205)

Instructors

• Gómez Cuba, Felipe
• Rodríguez Banga, Eduardo
• Rodríguez Lois, Elena

Contents

1. Introduction to digital communication systems

• Basic elements and general description of a communication system
• Analog and digital communications
• Description of a digital transmitter
• Description of a digital receiver

2. Signals, systems and stochastic processes in communications

• Review of basic concepts:
  • Signals and systems
  • Continuous-time Fourier transform
• Deterministic signals:
  • Energy-defined and power-defined
  • Autocorrelation
  • Spectral density
• Random variables
• Stochastic processes:
  • Stationarity
  • Autocorrelation
  • Power spectral density
  • Bandwidth
• White noise

3. Frequency conversion and analog processing

• Amplitude modulation (AM) and frequency modulation (FM)
• I/Q modulation and demodulation
• Transceiver requirements and specifications
• Receiver architectures:
  • Direct conversion
  • Intermediate frequency
• Analog and digital stages

4. Pulse amplitude modulation (PAM)

• Baseband PAM
• Bandlimited channels and intersymbol interference (ISI)
• Nyquist criterion
• Raised cosine pulses
• Eye diagram
• Matched filtering
• Bandpass PAM

5. Modulation and detection in Gaussian channels

• Introduction to the signal subspace
• Discrete equivalent channel
• Maximum A Posteriori (MAP) detection
• Maximum Likelihood (ML) detection
• Probability of error

6. The communication channel

• Transmission media
• Signal-to-noise ratio (SNR)
• Multipath and frequency selectivity
• Fading
• Doppler effect

Practical content

• No strict separation between theory and practice
• Includes practical exercises related to the theoretical contents

Learning Outcomes

• B3 CG3: The knowledge of basic subjects and technologies that enables the student to learn new methods and technologies, as well as to give him great versatility to confront and adapt to new situations
• B4 CG4: The ability to solve problems with initiative, to make creative decisions and to communicate and transmit knowledge and skills, understanding the ethical and professional responsibility of the Technical Telecommunication Engineer activity.
• B6 CG6: The aptitude to manage mandatory specifications, procedures and laws.
• C7 CE7/T2: The ability to use communication and software applications (ofimatics, databases, advanced calculus, project management, visualization, etc.) to support the development and operation of Electronics and Telecommunication networks, services and applications.
• C9 CE9/T4: The ability to analyze and specify the main parameters of a communications system.
• C10 CE10/T5: The ability to evaluate the advantages and disadvantages of different technological alternatives in the implementation and deployment of communication systems from the point of view of signals, perturbations, noise and digital and analogical modulation systems.
• C20 CE20/T15: The knowledge of national, European and international telecommunication regulations and laws.
• D2 CT2 Understanding Engineering within a framework of sustainable development.
• D3 CT3 Awareness of the need for long-life training and continuous quality improvement, showing a flexible, open and ethical attitude toward different opinions and situations, particularly on non-discrimination based on sex, race or religion, as well as respect for fundamental rights, accessibility, etc.

Recommended Readings and Tools

It is assumed that the student has basic knowledge of signal processing (both analog and digital), as well as probability and statistics.

Planned Activities

Lecturing

• Presentation and discussion of the fundamental theory
• Includes:
  • Explanation of concepts
  • Resolution of questions and exercises
• Skills developed:
  • C9, C10, C20, B3, B4, B6, D2, D3

Practices through ICT

• Concepts from lectures are:
  • Illustrated
  • Further developed
• Tools used:
  • MATLAB-based simulation
  • Signal processing tools
• Skills developed:
  • C7, C9, C10, B3, B4, D2

Assessment Methods and Criteria

Problem and/or exercise solving Three midterm exams will be given during the semester. Their influence on the final grade is detailed in the section "Other comments on the Evaluation". 

Problem and/or exercise solving Final examination with questions of any type. It will cover all of the material covered during the course and will take place during the exam period as established by the Center. The influence of the exam on the final grade is described in the section "Other comments on the Evaluation". 

Other comments on the Evaluation

The final grade will be computed based on the grades obtained in the three midterm exams (P1, P2 and P3, respectively) and the grade in the final exam (EX), all of them in a ten-point scale.

The contribution of the midterm exams to the final grade (P) is obtained as

P = V1*P1 + V2*P2 + V3*P3

where

V1 =0.15 if P1 >= 5, V1 = 0 otherwise

V2 =0.2 if P2 >= 5, V2 = 0 otherwise

V3 =0.25 if P3 >= 5, V3 = 0 otherwise

Then, the final grade (F) will be computed as:

F =min( 10, P + EX*(10-P)/(10-0.3*P) ) if EX>=3.5

F = min( 4, P + EX*(10-P)/(10-0.3*P) ) if EX < 3.5

The schedule of the midterm exams will be approved in the Comisión Académica de Grado (CAG) and will be available at the beginning of each academic semester. These exams are not recoverable, that is to say, if a student does not show up when they take place, the instructors do not have the obligation to repeat them. In each midterm exam, the material covered from the start of the course until the previous week (included) will be evaluated.

For those students who choose to follow global assessment, the final grade will be directly the final exam grade (F = EX).

Students will be graded at the ordinary opportunity of evaluation as long as they attend two of the four scheduled tests (the three midterm exams and the final exam) and do not waive the continuous assesment (C.A.) by sending an email to their instructors at least four days before the final exam. The waiver will be acknowledged shortly by a reply to the received email.

For those students following C.A., any not attended midterm exam or final exam will be graded with zero points.

The mark achieved in the three midterm exams (P) will be kept for the second call of evaluation to those students attending the final exam of that call, but not for subsequent years. Regarding this second call, the same rules stated above will apply.

For the end-of-program exam, a comprehensive exam will be given, corresponding to 100% of the final grade.

Plagiarism is regarded as serious dishonest behavior. If any form of plagiarism is detected in any of the tests or exams, the final grade will be FAIL (0), and the incident will be reported to the corresponding academic authorities for prosecution.