Friendly cooperation jamming for secrecy in LOS channel

A multiple nodes wireless communication network in LOS channel is considered, consisting of a sender (Alice), a receiver (Bob), several friendly helpers, and a passive eavesdropper (Eve), each equipped with an omnidirectional antenna. The helpers work cooperatively to jam Eve. But sender and helpers have no idea of the position of Eve, so the goal of the system is to jam equally to every direction except for the legitimate receiver. A random jamming pair scheme is proposed, in which each helper pair sends noise nulling at Bob, and the closed form direction pattern is derived. The outage performance of the scheme is introduced to measure the performance of the system in this paper, and we compare it with the conventional cooperative jamming scheme. The simulation results show that the random jamming pair scheme has a better outage performance than the fixed cooperative jamming scheme.