Research On Key Technologies Of Visible Light Camera Communication System Based On Color Space

With the widespread application of mobile Internet and industrial Internet of Things,traditional wireless communication systems are facing problems such as spectrum resource bottlenecks and electromagnetic interference.Visible light communication(VLC)technology uses low-cost light-emitting diodes(LED)and other lighting equipment for wireless data transmission,and has the characteristics of rich spectrum resources,no electromagnetic interference,and environmental protection.In recent years,the optical camera communication(OCC)system based on the CMOS camera as the receiver is more outstanding due to its simple structure and flexible application.This paper focuses on the implementation complexity and transmission rate in the optical camera communication system.The main work is as follows:1.Considering that the problem of low system transmission rate and unobvious color recognition caused by limited LED modulation bandwidth,and blooming effect in the visible light camera communication system,a multi-input single-output(MISO)4-color shift keying(4-CSK)modulation scheme based on YCb Cr color space is proposed.The feasibility has been verified through experiments.The experimental results show that the proposed scheme can significantly improve the color recognizability and the transmission rate of the system.After 0.8m free-space transmission,the QPSK-like constellation diagram in the YCb Cr color space is clearer;under the bit-error rate(BER)of 3.8e^-3,the required illumination intensity is required,the system can be reduced to 400lux,and its transmission rate reaches 21.48kbits/s.2.Considering that the transmission performance and implementation complexity of the visible light camera communication system,a spaced color shift keying(SCSK)transmission scheme based on HSB color space is proposed,and the feasibility is verified through experiments.Experimental results show that this scheme can effectively improve the transmission performance of the system and reduce the complexity of implementation.Without clock recovery and alleviating the blooming effect,the impact of inter-code interference can be effectively alleviated,and a data transmission capacity of 1.28kbits/frame can be achieved.