Reconfigurable Holographic Surface Enhanced Multi-User Terrestrial-Satellite Communications

This correspondence investigates a reconfigurable holographic surface (RHS)-enhanced terrestrial-satellite system for uplink multi-user communications. Specifically, each of multiple users employs an RHS as the transmitter to communicate with multiple low earth orbit satellites. By dynamically manipulating electromagnetic waves, the RHS can precisely control signal propagation, thereby reducing interference and enhancing reliability in terrestrial-satellite communications. Under this paradigm, we formulate a weighted sum rate maximization problem by satisfying the transmit power budget, and ensuring that the radiation coefficient for the meta-elements of the RHS remains below one. To solve the optimization problem, we apply the Lagrangian dual transform and alternative optimization to optimize the digital beamforming vectors and the radiation coefficient vectors for the RHS. Simulation results exhibit the achievable communication performance, and demonstrate the feasibility of the proposed optimization scheme.