Implementation and evaluation of frequency division multiplexing of numerologies for 5G new radio in ns-3

The New Radio (NR) access technology that is currently being developed by the 3GPP for fifth generation (5G) systems is expected to be extremely flexible to allow operation in a wide range of bands and address a variety of use cases. One of the key steps towards this objective is the inclusion of a set of numerologies, which are specified by subcarrier spacing and cyclic prefix. Different numerologies can be exploited to meet different quality-of-service (QoS) requirements in terms of latency and throughput. To achieve this, 3GPP specifies that the NR system shall support multiplexing of numerologies in time and/or frequency domain. In this work, we focus on frequency division multiplexing (FDM) of numerologies. To allow simulation of FDM of numerologies in the ns-3 network simulator, we have extended the mmWave module with some of the key features defined for NR systems. These extensions include support for NR frame structure, numerologies, and on top of that the FDM of numerologies. To implement the FDM of numerologies, we leveraged the carrier aggregation (CA) feature of ns-3 LTE module, and for that purpose, we have extended the mmWave module to support the CA functionality. In this paper, we describe these extensions and we carry out a performance evaluation of numerologies and FDM of numerologies.