Wireless Communications

Aim

The course provides basic knowledge about problems and methods for construction of radio communication systems. The main emphasis is on digital radio systems. In particular it is illustrated how different forms of signal processing are used for the construction of efficient radio communication systems. After completed course the student should be able to

• perform link budget calculations in connection to the design of wireless communication links.
• identify and describe various physical and statistical fading channel models.
• present modulation techniques for wireless communication and their spectral properties as well as evaluate their performance over fading channels.
• give an account for coding techniques which can be used for improvement of the transmission reliability.
• describe and solve problems about direct sequence and frequency hopping band spreading techniques.
• analyse and describe properties for various diversity methods.
• present and use the basic principles for design and analysis of wireless cellular systems
• give an account and solve problems about ARQ and some basic multiple access techniques.

Content

Lectures and exercise sessions treat the following areas within radio communications:

• Basics about radio communication systems: utilisation of the frequency spectrum, varioust radio systems.
• System oriented antenna and wave propagation theory: propagation in free space, in the troposphere, in the ionosphere, basic antenna theory, link budget.
• Probabilistic channel models: fading channels, time and frequency dispersive channels, digital channel models.
• Modulation methods for the radio channel: bit-error-rate analysis in fading channels, spectral properties, spectral efficient modulation,OFDM.
• Diversity methods: principles, weighting, performance.
• Coding for radio channels: methods for burst error correction, coding gain.
• Spread spectrum techniques: frequency hopping, direct sequence systems.
• Wireless packet transmission: ARQ, multiple access techniques - ALOHA and CSMA.
• Wireless cellular systems: basic concepts, frequency reuse capacity calculations.
• Practical examples: GSM, WLAN.