Experimental Study Of Visible Light MIMO Communication System Based On Color LED Arra

Nowadays,with the increasing demand for communication,the shortage of radio frequency spectrum resources is becoming increasingly serious.As a novel communication method,visible light communication is expected to solve this problem and has received widespread attention from researchers.Optical camera communication is a variant of visible light communication,which has the advantages of rich spectrum resources,environmental protection and energy conservation,low cost,and high security.Due to the popularity of smart devices,mobile phone cameras can be used as a receiving device for optical communication anytime and anywhere,which can solve the problem of difficult installation of visible light communication receiving terminals and has aroused scientists’ extensive interest.However,there are also some urgent difficulties in optical camera communication that need to be addressed.The primary factor limiting the development of optical camera communication is the camera frame rate.The frame rate of a camera is generally several tens of frames per second.If data is directly transmitted at this rate,the system communication rate will be limited to several tens of bits per second,making it difficult to meet communication requirements.Moreover,the communication system of visible light cameras still faces difficulties in synchronization between the receiving and transmitting terminals.In order to solve the existing problems,a visible light Multiple-Input-Multiple-Output(MIMO)communication system based on a Light Emitting Diode(LED)array is proposed.Sending data from multiple independent sources simultaneously and loading the data onto LED colors achieves the goal of doubling the system communication speed.A special frame structure was designed to verify effective data and synchronize the system’s transmitter and receiver by setting a verification data area on the edge area of the LED array.In order to improve the decoding rate of color images,a back-propagation neural network classifier is introduced into the color recognition process to improve the stability and scalability of the communication system.A MIMO mobile communication experimental system based on color LED was constructed and real-time communication experiments were conducted.We used the m sequence as communication data for experimental exploration,and analyzed the impact of various factors such as transmitter refresh rate,camera deflection angle,and transmission distance on communication system performance using communication error rate as a measurement standard.The experimental results indicate that the system can achieve stable information transmission within the communication range and achieve real-time communication with a rate of 4.824 kbps.