# A Power Control and Intervention Algorithm for Co-Existing IMT Base Stations and Satellite Services
## 1 Introduction  
Over the past few decades, the development of mobile communications has significantly influenced societal progress. However, the increasing data traffic demands further exploration of spectrum resources [1]. These resources must support extensive and continuous channel bandwidth. Spectrum sharing between networks has emerged as a key area of research [2]. However, deploying IMT-2020 systems across various frequency bands may interfere with other existing services [3]. In 2019, the World Radiocommunication Conference (WRC23) addressed this issue. It coordinated the 12.75-13.25-GHz frequency band, used by earth stations on aircraft and ships, for communication with geostationary space stations in the Fixed Satellite Service (FSS) [4; 5; 6]. This coordination ensures coexistence between existing services and IMT-2020 in these bands. Current research focuses extensively on the coexistence possibilities of IMT-2020 with other existing radio services. Several studies have explored co-channel sharing between IMT-2020 and Fixed Service (FS) systems [7]. [PERSON] et al. proposed analytical expressions for frequency-dependent suppression using CP-OFDM, windowed orthogonal frequency-division multiplexing, and filtered orthogonal frequency-division multiplexing. Thesemethods aim to assess the interference of IMT-2020 on existing radar systems. Extensive analyses have been conducted on the interference between IMT-2020 and satellite services. However, most of these studies focus on analyzing the interference between IMT-2020 and satellite earth stations, neglecting the interference received by satellite systems [8; 9; 10; 11; 12; 13; 14; 15; 16]. This is because satellite systems are located at high altitudes, where the interference from IMT-2020 is minimal. However, for interference-sensitive satellite systems, the aggregated interference from numerous IMT-2020 base stations distributed over a large area may still have significant impacts [17; 18; 19]. Therefore, to achieve complete coexistence of both services, it is necessary to estimate the interference received by existing satellite systems. Generally, there are two main methods for calculating aggregated interference: The first method involves calculating the interference power received by the satellite system from a single IMT-2020 system and then multiplying it by the number of IMT-2020 stations distributed within the satellite's main beam coverage [20]. The second method models a single cell of the IMT-2020 network using a hexagonal grid, calculates the interference received by the FSS satellite from this network, and finds the maximum number of networks that satisfy the protection standards [21]. The advantage of these methods is that after considering the interference from IMT-2020 distributed within a single or very small area, they can predict the interference power received from multiple IMT-2020 systems in a short period by multiplying by the coverage area. Both methods can serve as interference evaluation metrics for IMT-2020 and satellite services, demonstrating the aggregated interference received by satellites from IMT-2020. Although there have been studies on IMT-2020 interference received by satellite systems, research on interference avoidance remains insufficient. Suppressing IMT-2020 interference with satellite FSS services while minimizing or eliminating impacts on IMT-2020 systems, thus achieving complete coexistence of both services, remains an open issue [22]. Additionally, in GEO satellite FSS services, due to the high orbital altitude and large coverage of GEO satellites, there is a significant number of IMT-2020 base stations within their coverage area. Conventional power control or optimization methods face immense computational complexity and large-scale signaling interactions when dealing with numerous IMT-2020 base stations, which is nearly difficult to achieve in practical deployments [23].