Transmitting device of white light-based LED visible light communication system

Abstract

The invention discloses a transmitting device of a white light-based LED visible light communication system. The transmitting device comprises at least one set of input circuit, modulation circuit, driving circuit and LED array, wherein the input circuit receives analog electric signals inputted from the outside and transmits the analog electric signals to the modulation circuit, the modulation circuit acquires the analog electric signals and converts the analog electric signals into digital signals and transmits the digital signals to the driving circuit, and the driving circuit switches on the LED array according to the digital signals, and the LED array stably emits light according to the modulated signals, and therefore, electro-optic conversion can be realized. With the transmitting device of the invention adopted, the problem of incapability of an LED lamp to work stably when the voltage of modulated signals in a transmitting device is too low or does not accord with required grid pole driving voltage in visible light communication of an LED in the prior art can be completely solved.

Description

technical field [0001] The present invention relates to the communication field, in particular to a transmitting device for a visible light communication system based on a white light LED. Background technique [0002] Currently, if figure 1 As shown, in the white LED-based visible light communication system, the transmitting device can convert the electrical signal into an optical signal, and then send the optical signal to the receiving device through an optical channel, that is, free space, and finally the receiving device can receive the received signal with a certain frequency The optical signal is converted into a raw electrical signal. Among them, the core technology of the emission device of the white LED-based visible light communication system is the electro-optic conversion technology, and the core of the electro-optic conversion technology is the LED driving technology. [0003] Existing LED drive technologies include typical triode (NPN tube) drive, PWM contro...

AI Technical Summary

Problems solved by technology

This LED driving method has several unavoidable problems: first, the measurement of the current is inconvenient, and it is inconvenient to adjust; A very high magnification is required to drive the triode

Because the output current of general functional boards is very small, only in the milliampere level, it cannot be used directly; thirdly, triode drive is generally only suitable for low-power LED drive, and high-power LED requires a large drive current. current is difficult to reach

[0004] In the PWM control driving LED technology, although the brightness and color temperature of the LED lamp can be well controlled, there are several problems that need to be paid attention to: First, whether the PWM signal is generated by hardware or by software, it requires complex Peripheral circuits, high cost, large device noise

Second, PWM control drive technology is generally only suitable for low-power LED drive

[0005] In the capacitive voltage drop driving technology, the disadvantage of difficult adjustment and difficult measurement of the capacitance is obvious. In addition, the capacitance is a nonlinear element, and the process of charging and discharging takes a certain amount of time, and the problem of delay is unavoidable.

Although IC integrated drive LED technology has effectively improved the shortcomings of the above-mentioned drive technology, the cost of TC integrated chips is too high to be popularized.

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