Visible light communication (VLC) is a promising technology that complements existing wireless communication networks to provide high-speed, low-latency, and multi-device access. With the high-performance code modulation technology of traditional wireless communication, various physical layer communication technologies adapted to VLC systems have been designed and implemented. Different from traditional radio frequency (RF) communication, VLC uses LED as the signal source. The modulation of LED is easy to produce nonlinear distortion and the modulation bandwidth is limited. It has become the technical bottleneck of VLC high-speed communication. In view of the challenges of these two aspects, taking white LED as the starting point, this paper expounds that white LED can effectively balance the characteristics of illumination and communication, summarizes and classifies various techniques of nonlinear distortion compensation and extended modulation bandwidth. Finally, this paper proposes open research issues such as LED package materials and processes, new Micro-LED device research, light source layout design, and intercode interference cancellation technology are expected to improve the performance of visible light communication systems.