Consumption Factor and Power-Efficiency Factor: A Theory for Evaluating the Energy Efficiency of Cascaded Communication Systems

This paper presents a new theory, called the consumption factor theory, to analyze and compare energy efficient design choices for wireless communication networks. The approach presented here provides new methods for analyzing and comparing the power efficiency of communication systems, thus enabling a quantitative analysis and design approach for "green engineering" of communication systems. The consumption factor (CF) theory includes the ability to analyze and compare cascaded circuits, as well as the impact of propagation path loss on the total energy used for a wireless link. In this paper, we show several examples how the consumption factor theory allows engineers to compare and determine the most energy efficient architectures or designs of communication systems. One of the key concepts of the consumption factor theory is the power efficiency factor, which has implications for selecting network architectures or particular cascaded components. For example, the question of whether a relay should be used between a source and sink depends critically on the ratio of the source transmitter power-efficiency factor to the relay transmitter power-efficiency factor. The consumption factor theory presented here has implications for the minimum energy consumption per bit required to achieve error-free communication, and may be used to extend Shannon's fundamental limit theory in a general way. This work includes compact, extensible expressions for energy and power consumption per bit of a general communication system, and many practical examples and applications of this theory.