A flexibility metric and optimization methods for mixed numerologies in 5g and beyond

Mixed numerology-based frame structures will be a part of 5G systems in order to enhance overall flexibility and user satisfaction. However, inter-numerology interference, spectral efficiency reduction, complexity, and signaling overhead type of issues arise in such structures. It is needed to limit the number of numerologies used together. In this paper, a novel heuristic method is developed to find the efficient number of mixed numerologies. The proposed method aims to control overheads in systems using multi-numerology structures. Analysis of the trade-offs and relationships between different services and user requirements are also presented. The designed algorithm employs a new flexibility function and performance metric. Simulation results are shown for three different numerology sets, which include 5G numerologies.