Joint Optimization of Spectrum and Energy Efficiency Considering the C-V2X Security: A Deep Reinforcement Learning Approach

Cellular vehicle-to-everything (C-V2X) communication, as a part of 5G wireless communications, has been considered one of the most significant techniques for Smart City. Vehicles platooning is an application of Smart City that improves traffic capacity and safety by C-V2X. However, different from vehicles platooning travelling on highways, C-V2X could be more easily eavesdropped and the spectrum resource could be limited when vehicles converge at an intersection. Satisfying the secrecy rate of C-V2X, how to increase the spectrum efficiency (SE) and energy efficiency (EE) in the platooning network is a big challenge. In this paper, to solve this problem, a Security-Aware Approach to Enhancing SE and EE Based on Deep Reinforcement Learning is proposed, named SEED. The SEED formulates an objective optimization function considering both SE and EE, and the secrecy rate of C-V2X is treated as a critical constraint of this function. The optimization problem is transformed into the spectrum and transmission power selections of V2X links using deep Q network (DQN). The heuristic result of SE and EE is obtained by the DQN based on rewards mechanism. Finally, the traffic and communication environments are simulated by Python 3. The evaluation results demonstrate that the SEED outperforms the DQN-wopa algorithm and the baseline algorithm by 31.83% and 68.40% in efficiency, respectively.