Physical layer security for indoor multicolor visible light communication

In visible light communication (VLC), data is transmitted by modulating the light intensity, usually by using a lighting source as a transmitter. Multi-color VLC, on the other hand, enables data transmission at high speeds by using multiple color channels in parallel. It can be thought that VLC systems provide security indoors because light cannot pass through non-transparent surfaces, but data security must be ensured due to the presence of eavesdroppers in public environments. Data security can be achieved with physical layer security (PLS) techniques. PLS takes measures at the physical layer of the systems by taking advantage of the characteristics of the environment where the communication takes place to ensure security. In this thesis, VLC systems with single input single output and multiple input single output are discussed. Monochrome and multi-colored light emitting diodes (LEDs) are used as transmitters. Null steering and artificial noise techniques, which are PLS techniques, have been applied to VLC systems. The inter-channel interference effect is calculated and the obtained secrecy rate results are presented.