Multicomponent Secure Transmission Based on GMFRFT With Imperfect CSI

In this letter, a robust multi-component secure transmission scheme based on general multi-fractional Fourier transform (GMFRFT) with imperfect channel state information (CSI) is proposed and analyzed. The scheme combines signal and spatial domains for transmitted components design, aiming at degrading the wiretap channel utilizing the energy distribution characteristics of GMFRFT. The inter-component interference is only formed at the eavesdropper because of the broken GMFRFT signal, and its effect is similar to artificial noise (AN). Considering the problem of AN leakage in traditional AN-based scheme under imperfect CSI, the proposed scheme does not consume extra power and can further improve the secrecy performance when the available spatial degrees of freedom are limited. Numerical results are carried out to demonstrate the secrecy performance of the proposed scheme.