Signals and systems
Communications engineering examines how information is represented, transmitted and processed. A signal can, for example, be described as a voltage varying over time or as a sequence of digital samples. A system is considered in terms of how it transforms an input signal into an output signal.
This area provides a common starting point for analogue circuits, digital signal processing and the description of transmission systems.
Filters and spectra
A time-domain representation shows how a signal develops over time. The frequency domain offers another perspective on its composition. Filters can emphasise or attenuate selected frequency ranges. Their description includes phase behaviour and delay as well as magnitude.
This area makes room for filter designs, measured responses and clearly documented experiments. Parameters and operating conditions can be stated with each contribution.
Modulation and reception
Modulation involves influencing a property of a carrier with an information signal. A receiving system recovers the transmitted information from it. Describing the complete signal path includes frequency conversion, filtering and demodulation, among other processes.
This area can be expanded with original contributions on receivers, measurement setups and implementation in programmable hardware.