Introduction to Communication Systems

This textbook provides an introduction to the conceptual underpinnings of communication technologies. Most of us directly experience such technologies daily: browsing (and audio/video streaming from) the Internet, sending/receiving emails, watching television, or carrying out a phone conversation. Many of these experiences occur on mobile devices that we carry around with us, so that we are always connected to the cyberworld of modern communication systems. In addition, there is a huge amount of machine-to-machine communication that we do not directly experience, but which is indispensable for the operation of modern society. This includes, for example, signaling between routers on the Internet, or between processors and memories on any computing device.

We define communication as the process of information transfer across space or time. Communication across space is something we have an intuitive understanding of: for example, radio waves carry our phone conversation between our cell phone and the nearest base station, and coaxial cables (or optical fiber, or radio waves from a satellite) deliver television from a remote location to our home. However, a moment's thought shows that that communication across time, or storage of information, is also an everyday experience, given our use of storage media such as compact discs (CDs), digital video discs (DVDs), hard drives, and memory sticks.