Communications
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Core prerequisite:ECEN
3300 - Linear Systems
ECEN 4242 - Communication Theory
ECEN 4652 - Communication Lab
Faculty advisors:
One of the most fascinating and important topics in electrical communications is the wireless transmission and reception of analog and digital signals. Early examples, most of which are still in use today, include wireless communication using Morse signals and AM (amplitude modulation) and FM (frequency modulation) radio broadcasts. Modern examples of wireless systems are satellite radio and TV, wireless LAN's (local area networks), and cellular telephones.
All practical communication systems are affected by noise that is picked up during transmission, either by the communication channel itself or by the front-end of the receiver, and the signal-to-noise ratio (SNR) of the received signal is a crucial measure for the quality of a communication system. For analog systems, quality is synonymous with high fidelity reproduction of the transmitted signal. For digital systems, the main quality measure is the probability of bit or symbol error. Early on, the common perception was that in order to improve quality, more transmit power was needed. But it is now recognized that putting intelligence in various forms of coding into communications systems is an energy-conscious and smart alternative. Most modern communication systems use digital symbols to represent signals, independent of whether the original signal, like speech or music, is analog or, like computer data, is already digital. Source coding, like MP3 for example, and error-control coding can be applied easily to digitally represented signals. However, most physical channels require a waveform that is continuous in time and in amplitude and is restricted to a specific frequency range for efficient signal transmission. Thus, important topics for the treatment of communication systems are the study of signal processing of both analog and digital signals and the conversion between analog and digital representations.
Representative Technical Applications
- Wireless and wired transmission of analog and digital data
- Reliable reception of analog and digital data
- Information storage and retrieval
- Telephone network, cell phones, data networks
- Coding for compression, error-control, and secrecy/privacy
- Radio and TV broadcasts
Representative Societal Applications
- Voice and data communication for personal and commercial purposes
- Digital storage of multimedia including audio, images, and movies
- Wireless communication networks for remote areas
- Communications for rescue missions and disaster recovery
