As the landscape of sixth-generation (6G) wireless networks advances, low-Earth-orbit (LEO) satellite communication emerges as a promising solution for offering comprehensive global communication services, though its potential is challenged by severe large-scale path loss that significantly impairs the received channel capacity available to terrestrial users. To address this limitation, this paper investigates a federated learning aided distributed beamforming network for LEO satellite communications, namely the FederSat network. In order to enhance the average achievable rate of the LEO satellite networks, we propose a novel code-book-based distributed beamforming strategy in the FederSat networks. Through numerical analysis, we demonstrate that the proposed FederSat networks substantially outperform in average achievable rate. Additionally, more LEO satellites are encouraged for further enhancing the received signal power, which indicates that a mega-constellation LEO satellite network is preferable.

In order to provide communication services in a more efficient manner, and instead of using low-orbit communication satellites, we investigate an integrated navigation and communication (INAC) network by medium-orbit navigation satellites. In this article, non-orthogonal multiple access (NOMA) is investigated for facilitating the INAC information. In order to improve the received signal power level, we then introduce a reconfigurable intelligent surface (RIS)-aided INAC network. The navigation and communication signals can be reflected to the users located in the city center. Based on the different power allocation factors, navigation-oriented-INAC (NO-INAC) and communication-oriented-INAC (CO-INAC) are proposed to meet different application scenarios. The bit error ratio (BER) is calculated to illustrate the performance of both NO-INAC and CO-INAC. We analyze the results of single-point positions and multi-point positions. The numerical results demonstrate that: 1) The RIS-aided INAC network is able to successfully reflect the navigation and communication signals from the occluding satellite. 2) The proposed RIS-aided INAC network provides a new solution for satellite communications in a more efficient manner.

Global Navigation Satellite System (GNSS) is widely applied in the next generation wireless networks, where high-precision positioning is required. However, due to the impact of blockages, the high-precision positioning signals are blocked in the ultra-dense networks. In this article, we introduce a RIS-aided GNSS network, where more navigation links can be reflected to the users located at the city center. In order to evaluate the performance of the network, we analyze the results of multi-point location respectively. We also analyze the skyplot and dilution of precision (DoP) of the RIS-aided GNSS network. The numerical results show that: 1) The RIS assisted GNSS network is able to successfully reflect the navigation signals from the occluding satellite and realize the location calculation in the city center. 2) The location of RIS affects the positioning accuracy, and the appropriate RIS location is useful to improve the positioning accuracy.