A transmitter device for a visible light communication system based on white light LEDs

Abstract

The invention discloses a transmitting device of a visible light communication system based on a white light LED, which includes at least one set of input circuit, modulation circuit, drive circuit and LED array; wherein, the input circuit will receive an analog electrical signal input from the outside and The analog electrical signal is transmitted to the modulation circuit; the modulation circuit collects the analog electrical signal, then converts it into a digital signal and transmits it to the driving circuit; finally, the driving circuit lights up according to the digital signal The LED array enables the LED array to emit light stably according to the regulation of the modulation signal, so as to realize electro-optic conversion. Therefore, the present invention completely solves the problem that the LED lamp cannot work stably when the modulated signal voltage in the transmitting device is too low or does not match the required gate driving voltage in the visible light communication process of the existing white light LED.

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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