In this letter, we propose a user scheduling scheme, which enables non-scheduled users to generate artificial noise in order to enhance wireless security in a multiuser wiretap network, where there exist    $N$    users, a single desired receiver, and    $K$    eavesdroppers. Our proposed scheme can achieve the optimal multiuser diversity gain (i.e.,    $\log \log N$   ) by adopting appropriate threshold values for scheduling feedback, which is also able to significantly reduce signaling overhead. We mathematically prove the achievability based on the derivation of a  secure user-scaling law . Simulation results demonstrate that the proposed scheme achieves a better average secrecy rate than the conventional scheme in a finite    $N$    case, even if both schemes obtain the same  secure user-scaling law  as    $N \rightarrow \infty $   .
['Inkyu Bang', 'Su Min Kim', 'Dan Keun Sung']
Artificial Noise-Aided User Scheduling for Optimal Secrecy Multiuser Diversity