# _electronics_
## 1 Introduction  
Low Earth orbit (LEO) satellites can be used as extensions of terrestrial communication networks due to their broad coverage, low latency, and distributed load [1; 2; 3]; they also offer advantages in remote areas, mountainous, lake, and maritime networks, emergency communication, data broadcasting, and other scenarios [4; 5]. However, due to the limited resources of satellites, satellites face significant energy consumption and communication resource pressures when transferring large amounts of data, which seriously limit improvements in satellite data communication time and quality of service. Therefore, the idea of exchanging the storage space of satellite nodes with the consumption of the satellite's ground wireless link has been put forward. The cache in the satellite can reduce the communication traffic of the satellite's return link, reduce the communication pressure of the satellite, reduce the service delay of the user, and greatly improve communication efficiency. A new caching scheme, denoted as SatCache, was proposed in [6]; it utilizes the broadcasting characteristics of satellite communication media and creates network user preference profiles to estimate potential interest in a given content. The authors of [7] proposed a double-layer satellite network model for content distribution, which used the satellite as a caching module to cache high-frequency content in the network, and the downlink consumption between the satellite and core network was reduced. At the same time, the cache distribution of the large-scale satellite constellation has also been studied. The authors in [8] proposed a dynamic cache allocation algorithm-based matching game, which considered cache collaboration and cache redundancy between satellites to improve the utilization rate of the cache. The load balancing and allocation ofcache resources in multi-layer satellite networks are investigated and a distributed cache strategy based on the Stackelberg game is proposed in [9]. In recent years, some studies have begun to consider the use of fine-grained coded caching solutions. Coded caching [10] allows files to be divided into coded segments through coding and then caches them into different cache nodes. Users obtain different files from different cache nodes. Coding segments then decode those chunks into the full request file. The authors in [11] proposed a coded caching strategy applied to the satellite's unmanned aerial vehicle (UAV)-vehicle integrated network, which greatly reduced the backhaul traffic between geosynchronous Earth orbit (GEO) satellites and UAVs, saving more transmission energy consumption. In addition, some studies have introduced coded caching into satellite networks to achieve more efficient content distribution. The authors in [12] proposed a heuristic online coded caching scheme based on satellite networks, in which the auxiliary controller searched for opportunities in the aggregation window for linear network coding, according to the content cached in each access satellite. However, this scheme requires the auxiliary controller to go to the ground core end to retrieve the user's required content, code the content, and then distribute the content to LEO satellites. This solution is not very suitable for scenarios where users have large-scale and diverse requests. With the development of the LEO satellite networks, the future satellite communication networks will develop toward the trend of denseness. With the increase in the number of satellites, on the one hand, terrestrial users can enjoy the coverage of multiple satellite nodes at the same time. On the other hand, terrestrial users can realize the transmission characteristics, such as robustness enhancement and bandwidth aggregation, which are similar to terrestrial networks through multi-point cooperative transmission [13; 14; 15; 16]. In this paper, we propose a coded caching scheme of low Earth orbit satellite networks based on named data networking (NDN) [17].