Artificial Noise assisted Secure Transmission using Novel Beamforming Scheme based on Statistical CSI

We propose a secure transmission scheme that employs artificial noise (AN) to enhance information security. This scheme uses a novel beam design method based on a specific type of statistical Channel State Information (CSI) known as the channel statistical covariance matrix. The base station can acquire this matrix through prior measurements. By performing eigenvalue decomposition on this matrix, we can extract valuable engineering insights from its eigenvalue and eigenvectors, which represent beam domain information within the channel. Leveraging this information, we further design an optimization problem to minimize the eavesdropper's Signal-to-Noise-Plus-Interference Ratio (SINR) through joint optimization of beam selection and power allocation. Eventually, an iterative algorithm is proposed to solve this optimization problem. Numerical results reveal favorable secrecy performance of our beamforming scheme under CDL channel models.