Energy-Efficient Computation Offloading for Secure UAV-Edge-Computing Systems

Characterized by their ease of deployment and bird's-eye view, unmanned aerial vehicles (UAVs) may be widely deployed both in surveillance and traffic management. However, the moderate computational capability and the short battery life restrict the local data processing at the UAV side. Fortunately, this impediment may be mitigated by employing the mobile-edge computing (MEC) paradigm for offloading demanding computational tasks from the UAV through a wireless transmission link. However, the offloaded information may become compromised by eavesdroppers. To address this issue, we conceive an energy-efficient computation offloading technique for UAV-MEC systems, with an emphasis on physical-layer security. We formulate a number of energy-efficiency problems for secure UAV-MEC systems, which are then transformed to convex problems. Finally, their optimal solutions are found for both active and passive eavesdroppers. Furthermore, the conditions of zero, partial, and full offloading are analyzed from a physical perspective. The numerical results highlight the specific conditions of activating the three abovementioned offloading options and quantify the performance of our proposed offloading strategy in various scenarios.