Multi-Band Spectrum Sharing with Indoor Small Cells in Hybrid Satellite-Mobile Systems

In this paper, we present a technique for sharing spectrums of multiple systems with small cells deployed in 3D buildings to enhance spectral and energy efficiencies of heterogeneous mobile networks for 5G and beyond systems. The multiple systems consist of a space-satellite system and a terrestrial-mobile system incorporating in- building small cells. By taking advantage of high external wall penetration loss of a building and employing the ABS based eICIC technique to small cell base stations (SBSs), both the satellite spectrum and the mobile spectrum are proposed to share with SBSs by managing co-channel interference of SBSs with satellite and mobile systems. We derive system-level capacity, spectral efficiency, and energy efficiency metrics for multiband enabled SBSs and find the conditions for optimality in terms of the small cell density over a macrocell coverage to trade-off spectral and energy efficiencies of the mobile system. With extensive system-level simulation and numerical analysis, we evaluate the performance of the proposed technique for the multiband enabled SBSs and show its outperformance over a single band enabled SBSs as well as the requirements of the 5G mobile system, in terms of spectral and energy efficiencies.