Secrecy rate maximization for SIMO wiretap channel with uncoordinated cooperative jamming by single-antenna helpers

The issue of physical layer security for wireless communication with uncoordinated cooperative jamming (UCJ) is addressed in this paper, and we focus on the secrecy rate maximization (SRM) for single-input multiple-output (SIMO) wiretap channel with a multi-antenna intended receiver and a single-antenna eavesdropper. Differing from the existing schemes, we propose a new scheme for SRM by using multiple single-antenna helpers, where each helper transmits artificial noise independently to confound the eavesdropper. Our purpose is to design the jamming power of the helpers under individual or sum power constraints to maximize the secrecy rate with the assumption that global channel state information (CSI) is available. A robust iterative optimization method for power allocation is given to solve the SRM problem, and numerical results are finally provided to illustrate the performance of the proposed method in comparison with the existing works.