Pilot-Aided Multi-Light Source Diffuse Reflection Visible Light Communication Scheme

Visible light communication (VLC) is an important research direction for 6th-generation mobile networks (6 G). When the image sensor realizes the multi-light source diffuse reflection VLC based on code division multiple access (CDMA), the spread spectrum sequence used cannot be too long due to the limitation of sensor hardware. The increase in the light sources will produce serious cross-correlation interference, which affects the communication performance of the system. This paper proposes a pilot-aided multi-light source VLC scheme. Firstly, at the optical transmitter, a light source's emission waveform combination is designed, and the orthogonal and non-orthogonal sequences are used as the spread spectrum sequences of the communication and the pilot light sources. The pilot light source provides the synchronous function for the communication light sources, effectively solving the problem of cross-correlation interference and signal synchronization between the communication light sources. Secondly, at the optical receiver, this paper proposes a demodulation algorithm for the diffuse reflection superimposed signal corresponding to the emission waveform combination, aimed at accurately recovering the information transmitted by the communication light sources. The simulation results show that the proposed scheme can achieve good lighting effect and meet the basic communication requirements.