摘要

This paper investigates an agile confidential transmission strategy combining big data driven cluster and opportunistic beamforming (OBF) in the scenario where the same huge content is downloaded simultaneously by many users from the same base station. Instead of a burden from the traditional perspective, big data can be viewed as a resource. With the help of big data, data driven cluster taking into account security issues can be formed. Due to some obvious advantages, physical layer security (PHY-security) techniques as an alternative to the traditional high complexity cryptography-based secrecy methods are employed to achieve confidential transmission. For the purpose of superior secrecy performance, the scheme combining big data driven cluster and OBF, each of which can configure limited communication resources agilely and effectively in a dynamically changing network environment, is proposed. As the number of authorized users increases in the system, not only the channel vectors of cluster heads can tend to match with beamforming vectors with a high probability, but also more authorized users can be added into clusters and attain confidential content. These advantages ensure the combination of these two techniques is an attractive approach to transmit confidential message at a high rate. Based on different demand cases, multiple versions of the scheme combining cluster and OBF are put forward. In order to validate our proposed schemes, numerical simulations are carried out and the results show that a significant performance gain over both the average secrecy sum-capacity and the average number of authorized users accessing the system is achieved.