Secrecy Rate Optimization of Cellular Networks with Jamming Based on Imperfect Wiretap CSI

In this paper, we investigate the security of cellular networks using cooperative jamming with imperfect wiretap channel status information (CSI). Firstly, the CSI of the eavesdropper is considered imperfect and modeled as a sphere with a certain center and a radius which is the estimated channel of eavesdropper, and then the optimization of the worst-case secrecy rate is given. Secondly, using semidefinite relaxation (SDR) and a search method, the SDR-based scheme is proposed to maximize the secrecy rate. To reduce the complexity, a second scheme to optimize the ratio between interference to the eavesdropper and to the legitimate user, which is transmitted by jammers, is introduced. Finally, the numerical results demonstrate the excellent performance of the two strategies, and the performance of the low-complexity scheme is very close to that of the SDR-based scheme.