Securing Aerial-Ground Transmission for NOMA-UAV Networks

The efficient spectrum utilization of non-orthogonal multiple access (NOMA) and flexible mobility of unmanned aerial vehicle (UAV) enable NOMA UAV to become a prospective approach for future wireless networks. However, its secure transmission remains a great challenge. in this article, we summarize several potential solutions to mitigate adversarial eavesdropping toward aerial-ground transmission in NOMA-UAV networks, and propose three effective security schemes accordingly. First, a power allocation scheme is proposed at the UAV to ensure the privacy of a specific user with the sum transmission rate of others maximized. A closed-form solution is derived. Then, beamforming is leveraged to provide efficient privacy protection for multiple users in the network via jointly optimizing the precoding vectors to avoid eavesdropping and to maximize the spectrum efficiency. Finally, we perform artificial jamming together with beamforming to protect all the users in the network. Numerical results are provided to evaluate the superiority of the proposed schemes. Some future research issues and challenges of this direction are also pointed out.