LED lighting and VLC (Visible Light Communication) communication circuit and method with PWM/OFDM (Orthogonal Frequency Division Multiplexing) dimming modulation

Abstract

The invention discloses an LED lighting and VLC (Visible Light Communication) communication circuit and a method with PWM / OFDM (Orthogonal Frequency Division Multiplexing) dimming modulation. The positive electrode of a first LED driving power supply of the circuit is connected with the anode of a first LED lamp load; the cathode of the first LED lamp load is connected with the drain of a first switching transistor; a second LED driving power supply is connected with the anode of a second LED lamp load, and the cathode of the second LED lamp load is connected with the drain of a second switching transistor; the source of the first switching transistor is respectively connected with the source of the second switching transistor and one end of a network transformer secondary winding; the negative electrode of the first LED driving power supply is respectively connected with the other end of the network transformer secondary winding and the negative electrode of the second LED driving power supply; and one end of a VLC data source is connected with one end of a network transformer primary winding, and the other end of the VLC data source is connected with the other end of the network transformer primary winding. Thus, an OFDM fast algorithm for VLC communication can be realized, and lighting dimming optical feature requirements can also be realized.

Description

technical field [0001] The invention belongs to the field of lighting and communication dimming capable of realizing lighting dimming and visible light communication at high communication rates, and in particular relates to an LED lighting and visible light communication dimming circuit and method thereof combining PWM dimming and OFDM. Background technique [0002] As the fourth-generation lighting source, LED is a semiconductor solid-state lighting device. Compared with incandescent lamps and energy-saving lamps, LED not only has high efficiency, long life, small size, but also has the advantages of short response time and good modulation performance. [0003] Visible Light Communication (VLC) technology uses the high-speed response speed and modulation performance of white LEDs to modulate the signal to the visible light emitted by LED lamps to realize lighting and The dual role of communication. IEEE has formulated OOK, CSK, and VPPM modulation methods commonly used in...

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Problems solved by technology

[0006] The purpose of the present invention is to solve the problem that bipolar OFDM can transmit OFDM signals only in the "on" state of PWM dimming, and the OFDM signal is cut off in the "off" state, and provide a LED lighting modulated by PWM / OFDM dimming Communication circuit and method with VLC

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