### Signal Representation

The mathematical description of communication signals in the time and frequency domain is covered: Fourier series for periodic signals, Fourier transform for aperiodic signals with low-pass and band-pass characteristic and the special features of discrete-time signals. Scope: 2L + 1E.

### Linear and Time-Invariant Systems

Based on the book "Signal representation", it is described how the influence of a filter on deterministic signals can be mathematically determined. The book deals with distortion, the Laplace transform for causal systems and the properties of electrical lines. Scope: 2L + 1E.

### Theory of Stochastic Signals

The focus is on stochastic signals and their modelling. Starting from probability theory, discrete-valued and continuous-valued random variables without and with statistical bindings are introduced and the influence of a filter on stochastic signals is described. Scope: 3L + 2E.

### Information Theory

The book covers Shannon's information theory for discrete-valued and continuous-valued sources and his theorems for source and channel coding. Channel codes specifically add redundancy, source codes remove unnecessary redundancy (data compression). Scope: 2L + 1E.

### Modulation Methods

This book describes the basics of analog and digital transmission. It covers both the analog modulation schemes (AM, PM, FM) and the more important digital modulation (ASK, PSK, FSK, QAM, ...) as well as multiple access methods (CDMA, OFDM). Scope: 3L + 2E.

### Digital Signal Transmission

The bit error probability is the decisive quality feature of digital systems.

Its calculation is first explained for idealized conditions, then taking into account line coding and intersymbol interference. Finally,

digital channel models are discussed. Scope: 3L + 2E.

### Mobile Communications

If the transmitter and/or receiver moves, the channel is time-variant. Non-frequency-selective fading (Rayleigh, Rice) and frequency-selective fading due to multipath reception are treated. GSM and UMTS are briefly described, the 4G system LTE in more detail. Scope: 2L + 1E.

### Channel Coding

Channel coding includes methods for error detection and correction, which often are the only factors, that make transmission possible when the channel is poor. Described are linear block codes, Reed-Solomon codes and convolutional and turbo codes as well as their (possibly iterative) decoding. Scope: 3L + 2E.

### Examples of Communication Systems

The last textbook uses current and commercially successful communication systems to show that the theoretical foundations of the other books are certainly relevant to practice. ISDN and DSL for the landline network and the mobile communication systems GSM and UMTS are considered. Scope: 3L + 1E.

### Biographies and Bibliographies

The last book of our eLearning offer "LNTwww" contains biographies of important engineers and scientists and a compilation of suitable technical literature for the individual books. In addition, the many people involved in this eLearning project (in one form or another) are introduced.