Smartphone Based Visible Light Communication Protocol Design And Implementation

In recent years,visible light communication(VLC)has received great attention.It is an alternative choice for next-generation wireless communication due to its unregulated bandwidth,ubiquitous infrastructures support and wider application field compared to traditional wireless communication.Benefited from the wide usage of light-emitting diodes(LEDs),VLC could realize data transmission or accurate indoor positioning by modulating LEDs.With the development of smartphone hardware,its performance has become higher than ever before.It has been able to handle complex tasks and has better portability than PCs.LED-based VLC is studied in this thesis.Combining with LEDs and widespread smartphones,the VLC system from LED to the smartphone is realized,which widen the application of short-range VLC.It proposes a brand-new scheme for data transmission of smartphones,which has broad application prospects and research value.Existing researches on VLC mainly based on LEDs and photodiodes,LEDs are utilized as the sender and PDs as the receiver respectively.These systems did not apply the smartphone as the receiver,which has poor scalability,thus the application of these systems is limited.Meanwhile,there are some smartphone-based systems,which no longer applies LEDs as the sender,usually result in high system costs.With the consideration of the system construction costs,this thesis designs VLC protocols based on LED and smartphone.The system prototypes are implemented according to the protocol design.The main researches and contributions of this thesis are as follows:(1)We design a VLC protocol based on On-Off Keying modulation called LCP(LED Camera Protocol),which can be used for single-user data transformation.(2)We also design a Color Shift Keying-based VLC protocol for multi-user data transmission called RLMP(RGB LED Multi-user Protocol),which can be used for multi-user data transformation.(3)We implement two feasible systems based on the proposed protocols,which provide testbeds for the two protocols.In this thesis,the OOK and the CSK modulation methods of the LED are studied respectively.The communication protocols for single-user and multi-user data transmission are designed.Short-range VLC system prototypes are implemented based on proposed protocols,which provide a new data transmission scheme for smartphones.