Date Added: Jan 2010
Electro-magnetics provides the ground for a physical theory of communications, while information theory and signal theory approach the problem from a purely mathematical point of view. Nevertheless, the latter theories frequently do refer to physical terms, such as: energy, power, noise, antennas, or waves. It is strange enough, that, at present time, there is no provision being made such that the usage of such terms in information theory is at least consistent with the governing physics. More of-ten than not, this results in less than optimum signal processing solutions and does not contribute to a complete understanding of communication systems.