# ELT-41308 Communication Theory, 5 cr

#### Additional information

Course home page: http://www.cs.tut.fi/courses/ELT-41307/

#### Person responsible

Mikko Valkama

#### Lessons

Implementation | Period | Person responsible | Requirements |

ELT-41308 2019-01 | 1 - 2 |
Mikko Valkama |
Exam and a personal project work. It is also possible to pass the course without taking the exam, by actively attending the learning events. More details will be provided on the course website. The exam and the project work should be done during the same academic year. |

#### Learning Outcomes

This course focuses on the most fundamental elements, processing methods and laws and boundaries stemming from the nature that are encountered in all electrical and electromagnetic communication systems (Internet, mobile radio networks, WLANs/WiFi, etc.). These include the concepts of filtering and modulation and phenomena like noise, distortion and interference. Also fundamental information theoretic bounds applicable to all communication systems are covered, and how they are related to concepts like bandwidth, energy and noise power. After passing the course, the student is able to: **identify the most common signal level phenomena and signal processing methods behind electromagnetic transmission systems as well as their significance to transmission. These include noise, modulation, and filtering, among others. **apply tools of signal and system analysis, such as Fourier transform and convolution, to study, among others, the effects of distortion, noise, and interference caused by the transmission channel and electronic components. **explain the characteristics of random signals such as correlation, stationarity, ergodicity, power spectrum, and probability distribution and is able to describe the related mathematical models. **explain the characteristics of bandpass signals, such as envelope, phase, and spectral content, and is able to describe the related mathematical models. **explain the function and characteristics of most common digital modulation methods used in communication systems. The student is able to justify for practical design decisions from the viewpoint of signal power, bandwidth, and hardware implementation. **identify the basic resources related to designing and optimizing communication waveforms and devices such as power and bandwidth and is able to explain the related trade-offs. The student also identifies the basic modules of radio electronics, such as filters and mixers, and is able to explain how they work. **identify the basic concepts of information theory such as information, entropy, mutual information, and channel capacity, and is able to explain their significance to transmission. **explain and analyze properties of communication waveforms and the operation of communication devices using complex-valued signal models, and based on this, design new communication waveforms.

#### Content

Content |
Core content |
Complementary knowledge |
Specialist knowledge |

1. |
SIGNALS AND COMMUNICATION SYSTEMS ** signal spectrum and related concepts; ability to think and understand the behaviour of signals and systems in frequency domain; Fourier transform, correlation analysis and spectral density ** random signals and noise; 1st and 2nd order statistics and their significance; probability densities; random signals and spectral density ** signal distortion in transmission; various distortion types and their significance ** transmission system design and the crucial resources and boundaries; bandwidth, power and energy | ||

2. |
BANDPASS SIGNALS AND SYSTEMS ** understanding and expressing bandpass signals; envelope and phase functions; I/Q representation ** real and complex signals; lowpass equivalent signals and systems; analytic signals and Hilbert transform ** use of complex signals in communications systems; analysis vs. implementation | - analytic signals and Hilbert transform and their significance and applications in communications signal processing in general - complex filters and filtering | |

3. |
CARRIER MODULATION ** the concept of carrier modulation and how to use the different degrees of freedom that generic bandpass signals have for carrier modulationi ** concepts of I/Q modulator, I/Q demodulator ** concepts of envelope detector and frequency detector | "old"/historic analog modulation methods and their analysis in e.g. noise channels | |

4. |
SIGNAL SAMPLING ** continuous waveforms and their disrete-time samples; mathematical models for sampling; discrete sequence of numbers vs. impulse train model; spectral contents of sampled signals ** sampling theorem; lowpass vs. bandpass sampling | ||

5. |
DIGITAL MODULATION AND DIGITAL COMMUNICATION BASICS ** discrete information and analog channels; bits, symbols and waveforms ** baseband pulse amplitude modulation (PAM); line coding and Nyquist pulse shaping; symbol alphabets; intersymbol interference (ISI) ** carrier modulation in digital communication; linear digital I/Q modulation; digital frequency modulation; digital multicarrier modulation (OFDM) ** fundamentals of multiantenna/MIMO techniques ** digital vs. analog transmission, pros and cons | ||

6. |
INFORMATION THEORY BASICS ** basic concepts of information theory, namely information, entropy and mutual information ** information theory and source coding ** channel capacity; most fundamental limits imposed by noise, bandwith and power on all electrical and electromagnetic communications ** Shannon capacity laws |

#### Study material

Type |
Name |
Author |
ISBN |
URL |
Additional information |
Examination material |

Book | Communication Systems : An Introduction to Signals and Noise in Electrical Communication | A. B. Carlson, P. B. Crilly, J. C. Rutledge | 0-07-112175-7 | Available in TUT Library, Published by McGraw-Hill | No | |

Summary of lectures | Communication Theory -lecture notes | Mikko Valkama | Comprehensive lecture notes about the course contents. Available in both English and Finnish | Yes |

#### Prerequisites

Course | Mandatory/Advisable | Description |

ELT-40002 Tietoliikennetekniikan perusteet | Mandatory | 1 |

MAT-02500 Todennäköisyyslaskenta | Advisable |

1 . or ELT-40007 Basic Course on Communications Eng.

**Additional information about prerequisites**

Or equivalent knowledge acquired in other prior studies
In summary, it would be good to understand the very basics of the following:
- very basic theory of linear systems and filters
- very basics of electrical communications (concept of modulation, etc.)
- elementary basics of probability calculus
...though I'll provide a recap of these fundamentals also along this course

#### Correspondence of content

Course | Corresponds course | Description |

ELT-41308 Communication Theory, 5 cr | ELT-41307 Communication Theory, 7 cr |