Dynamic Cell Division for Interference Management in Satellite Direct-to-Cell Systems

Direct-to-cell (D2C) connectivity enables future non-terrestrial networks to provide service directly to standard terrestrial user equipment (UE) when terrestrial networks (TN) are unavailable. In this work, the satellite system is considered as a secondary network that supplements existing TN coverage while minimizing interference to the primary terrestrial infrastructure. To achieve this goal, we propose a dynamic cell-division framework in which satellite cells are adaptively formed to balance coverage and interference constraints. For UEs located near TN cells, a projected gradient descent algorithm is developed to place satellite cells as far as possible from the TN while maintaining user coverage. For UEs located far from the TN, a minimum covering cell (MCC) algorithm is employed to efficiently serve remote users while limiting the increase in the total number of cells. Simulation results demonstrate that the proposed method significantly reduces interference to the terrestrial network compared with conventional hexagonal cell layouts and the conventional MCC algorithm. In other words, the proposed method enables higher throughput without increasing the interference level compared to conventional approaches.