Base Station Transmission Power Optimization in Interference-limited Cellular Networks for Maximum Energy Efficiency

This paper proposes a novel solution to maximize energy efficiency (EE) in interference-limited (IL) cellular networks encountered in Long-Term Evolution (LTE) and LTE-Advanced systems. The high-data rate applications running through mobile devices together with the radio access devices at the base stations (BS) cause a significant growth in energy consumption in the network accounting a large share of network operation expenditure (OpEx), as well as increased carbon emissions. Unlike an interference-free network, in the IL cellular network, a monotonically increase of the transmission power does not necessarily improve the spectral efficiency (SE) of the network. For the analysis of the EE an information theoretic approach is applied and represented as a function of the BS transmission power considering the interference signals. A gradient based optimal level solution for the BS transmission power is derived to maximize EE. A network operator can significantly reduce the energy cost by setting the transmission power of the BS at the optimum level.