A Physical Layer Security Approach Based on Optical Beamforming for Indoor Visible Light Communication

Secure transmissions are important for visible light communication (VLC) systems. However, conventional information security technologies may be not suitable for VLCs due to the limited hardware resources especially for the receivers. In this letter, we conduct a security zone in the room and propose a physical layer security approach based on optical beamforming to achieve secure transmissions. First, we formulate an optimization problem to maximize the received signal power of the security zone so that the eavesdroppers in the insecurity zone can not obtain enough signal power for decoding. Then, a cuckoo search with adaptive searching and population mutation (CSASPM) algorithm is proposed to solve the formulated optimization problem. CSASPM introduces the adaptive searching and population mutation factors to improve the performance of conventional cuckoo search algorithm so that making it more suitable for the secure transmission optimization of VLC. Simulation results demonstrate that the proposed approach is effective and has better performance than other comparison methods.