Large-scale MIMO satellite mobile communication downlink transmission method and system

TLDR: In this paper, a large-scale MIMO satellite mobile communication downlink transmission system with maximum reachability and rate was proposed. But the authors focused on the downlink precoding vector design problem, which was converted into a multi-times convex optimization sub-problem.

Abstract: The invention discloses a large-scale MIMO satellite mobile communication downlink transmission method and a large-scale MIMO satellite mobile communication downlink transmission system with maximum reachability and rate. A satellite or a gateway station calculates a precoding vector corresponding to each user terminal through an iterative algorithm by using statistical channel information of eachuser terminal according to traversal reachability and rates of all users or an upper bound maximization criterion of all the users; downlink precoding transmission is carried out by using the obtained vector. According to the iterative algorithm, a precoding vector design problem is converted into a multi-times convex optimization sub-problem, a precoding vector is obtained by iteratively solvingthe convex optimization sub-problem, or the convex optimization sub-problem is converted into a Lagrange multiplier optimization problem, a Lagrange multiplier is iteratively solved, and then the precoding vector is calculated. And the user terminal performs frequency and time compensation on a received signal by utilizing Doppler frequency shift caused by satellite movement and minimum propagation time delay of long-distance propagation. According to the invention, the reachability and rate performance of a satellite mobile communication system can be improved, and the calculation complexityis relatively low.