A novel approach for dynamic spectrum sharing between LTE and NR in heterogeneous networks

Abstract

In this paper, we present a Dynamic Spectrum Sharing (DSS) technique between Long-Term Evolution (LTE) and New Radio (NR) using Multicast-Broadcast SingleFrequency Network (MBSFN) subframes in a heterogeneous network, consisting of a macrocell (MC) and, within its coverage, a set of picocells (PCs) located outdoors and small cells (SCs) situated in multistory buildings. Both the MC and PCs run on the LTE spectrum, whereas SCs use NR running on the same LTE spectrum employing DSS. An analytical model is presented to define the optimal MBSFN Frame Periodicity (pMBSFN) for serving NR users at any renewal time, given a fixed Number of MBSFN (nMBSFN) subframes per frame. Our findings show that DSS significantly improves Spectral Efficiency (SE) and Energy Efficiency (EE). Specifically, for the minimum pMBSFN of one and the maximum of six subframes per MBSFN frame, SE and EE improve by 10% and 57.5%, respectively, compared to no DSS. However, with a minimum subframe of 1 per frame, these SE and EE gains drop to 1. 8% and 1 0%}, respectively. Conversely, at the maximum pMBSFN of 32, with a maximum of 6 subframes per frame, gains decrease to 0.3% for SE and 2% for EE. Gains are negligible at the minimum subframes. © 2025 IEEE.