Power and Energy Efficiency Optimization of Baseband Transmission Links

Abstract

Power and energy consumption of communication networks contribute to the resource demand and hence they impact the sustainability of the society. Transmission links form basic parts of communication networks and thus they add to the overall communication networks' resource demand. Therefore it is important to optimize transmission links in order to support the energy-efficient design of communication networks. In transmission systems the constellation size in general is a degree of freedom when designing a transmission link. In this contribution, multilevel baseband transmission via additive white Gaussian noise (AWGN) channels and over copper cables is optimized with respect to minimum power and energy demand, respectively - for the relevant case of given throughput and fixed transmission quality of a link. The results are two-fold: In the AWGN case the minimum power and energy is required at the smallest possible constellation sizes. In case of band-limited baseband transmission over twisted-pair copper wires the optimum constellation size increases as the band limitation becomes stronger, i. e., as the cable gets longer at fixed bit rate or as the bit rate is increased at fixed link length. The optimization of the constellation size allows for significant power and energy savings per link.