## Circuit Theory and Communications

Module Number: EI7440

Duration: 1 Semester

Occurence: Winter Semester

Language: English

Number of ECTS: 5

## Staff

Professor in charge: Wolfgang Utschick

## Amount of work

Contact hours: 60

Self-study hours: 90

Total: 150

## Recommended requirements

Fundamentla knowledge: - Linear Algebra, - Elektrical Networks, - LTI SystemsThe following modules should have been passed successfully:- Circuit Theory- Adaptive and Array Signal Processing- Linear Signal Processing

## Contents

The high level of abstraction makes information theory a versatile and powerful tool for the analysis and optimization of a wide variety of communication systems. On the other hand, information theory has no concept of the flow of energy that accompanies the flow of information. Consequently, some important aspects of communication, like transmit power or noise covariance are by no means straight forward. In this lecture, we introduce effective methods which overcome this inherent limitation of information theory. We deal with this problem from a classic circuit theory point of view. This allows correct assessment of the energy flow in communication systems and thereby enables an information theoretic analysis and optimization which is consistent with the underlying physics of the communication system under investigation. After developing appropriate circuit theoretic channel models, we analyze the performance potential of different kinds of multi-antenna radio communication systems. Besides the study of channel capacity, we also develop interesting insight into receive and transmit antenna gain, super-directivity and super-resolution. A knowledge of circuit- and information theory is helpful but not strictly required, as all necessary methods are introduced during the lecture.

## Study Goals

After completion of the module students are able to apply multigate circuit theory and therewith develop a physically consistent model of communication systems. With these students develop an insight into the behavior of multi antenna systems and are able to optimise them. They are able to make connections to disciplines like information theory and signal processing.

## Description of achievement and assessment methods

Lecture and calculations in tutorials. Individual methods of problem solving during homework.

## Literature

N. Balabanian, Fundamentals of Network Theory, Allyn & Bacon, Prentice-Hall, 1961