New Aspects of Electromagnetic Information Theory for Wireless and Antenna Systems

IEEE Transactions on Antennas and Propagation, 2008. — Vol. 56, №11. — P. 3470-3484.This paper investigates information-theoretic characterization, via Shannon’s information capacity and number of degrees of freedom, of wave radiation (antenna) and wireless propagation systems. Specifically, the paper derives, from the fundamental physical point of view of Maxwell’s equations describing electromagnetic fields, the Shannon information capacity of spacetime wireless channels formed by electromagnetic sources and receivers in a known background medium. The theory is developed first for the case of sources working at a fixed frequency (timeharmonic case) and is expanded later to the more general case of temporally bandlimited systems (time-domain fields). In the bandlimited case we consider separately the two cases of time-limited and essentially bandlimited systems and of purely bandlimited systems.