Spectral efficiency-energy efficiency tradeoff analysis for a carrier aggregated 5g nr based system

Abstract

For 5G and beyond 5G systems, many technologies such as Carrier Aggregation (CA) have been suggested to improve the Spectral Efficiency (SE). Along with SE, Energy Efficiency (EE) is another key parameter to be considered while designing such systems. Judiciously using available power will not only help in reducing operational costs but also make the system more environment friendly by reducing greenhouse gas emissions. From an operator’s point of view, providing better data rates to users as well as reducing operational costs is important. This paper focuses on the tradeoff between SE and EE for a system operating in the FR1 frequency band (5G) and also using CA. Detailed analysis on the effect of various parameters such as 5G NR numerology, user velocity (Doppler shift), static and signal processing power consumption of base station and power amplifier efficiency at the base station in the tradeoff between SE and EE is performed. From the simulation results, it can be observed that while varying Doppler shift has very little impact, other parameters such as numerology, static and signal processing power consumption and power amplifier efficiency greatly affect the tradeoff between SE and EE. Tradeoff improves for lower subcarrier spacing, lower static and signals processing power consumption and higher power amplifier efficiency. For simulations, a TDL-A channel model is used. A base station power consumption model which takes into account both static and signal processing power consumption and power amplifier efficiency are considered in order to provide a more practical analysis of EE.