Shogo Kurimoto and Daichi Kishino (Waseda University, Japan); Keita Kuriyama (NTT Corporation, Japan); Fumiaki Maehara (Waseda University, Japan)
A hybrid multiple access scheme is proposed that dynamically switches between multi-user multiple-input multiple-output (MU-MIMO) and band-splitting non-orthogonal multiple access with maximum ratio transmission (NOMA-MRT), based on user-side interference sensing. To mitigate inter-cell interference, which is a critical issue in densely deployed cellular networks, each user equipment estimates the interference level by measuring the received power during signal-absent periods and reports it to the base station. The base station selects MU-MIMO under low interference conditions to exploit spatial multiplexing, and switches to band-splitting NOMA-MRT under high interference, where frequency subband partitioning reduces intra-cell interference. Simulation results demonstrate that the proposed scheme achieves robust throughput performance across various interference conditions, outperforming traditional MU-MIMO, NOMA-MRT, and orthogonal multiple access (OMA-MRT) schemes.