Secure transmission of high frequency ground waves based on massive multiple input multiple output

A ground-wave transmission method based on multistation coordination is proposed to improve the user rate and security performance of ground-wave communication by combining multipoint coordination and massive multiple input multiple output technology. In this system, the core network divides the original message sent to the user into several sub-messages, which are then sent to the user by a corresponding fixed station. A joint optimization model comprising the precoding vector, transmit power, and fixed station selection is established using multiple fixed stations equipped with multiple antennas for cooperative precoding to maximize the user rate. The closed-form solution of transmit power is derived using a precoding method based on conjugate beamforming. This paper proposes a low-complexity algorithm for a fixed station selection to solve the mixed-integer optimization problem of fixed station selection. The simulation results show that the proposed method can improve user and security rates. Furthermore, the proposed power optimization method can improve the security rate on the premise of ensuring the user rate. The performance of the proposed fixed station selection algorithm is almost similar to that of the exhaustive search algorithm, proving the effectiveness of the algorithm. © 2023 Editorial Board of Journal of Harbin Engineering. All rights reserved.