Analysis of Information and Power Transfer in Wireless Communications

An analysis of wireless information compared to power transfer over the same channel, consisting of a transmitting and receiving antenna system, is discussed. This frequency-selective additive-white-Gaussian-noise channel displays a fundamental tradeoff between the rate at which energy and the rate at which reliable information can be transmitted over the same channel, as in an RFID system, a power-line communication system, or for an energy-harvesting system. The optimal tradeoffs between power transferred and the channel capacity due to Shannon (which is additive-white-Gaussian-noise limited), Gabor (which is interference limited), and Tuller (which is defined in terms of the signal and noise amplitudes, and not power) are compared, and the differences are discussed. The appropriate use of each of the channel-capacity formulations for a frequency-selective transmitting/receiving antenna system in wireless communication is then computed as an illustrative example, to describe the tradeoff between wireless power transfer and wireless information transfer over a transmitting/receiving antenna system.