Visible light communication light modulation control method and system based on coding

Abstract

The invention discloses a visible light communication light modulation control method and system based on coding. A transmitting end is used for coding and signal transmitting, and a receiving end isused for signal receiving and decoding. The method comprises the steps that the transmitting end generates a binary transmission data stream; the transmitting end obtains an input light modulation level; the transmitting end performs the weight threshold coding of the transmission data stream; the transmitting end modulates a transmission signal into an optical signal, and the receiving end converts the optical signal into an electric signal; the receiving end performs the maximum likelihood demodulation of the received signal; the receiving end performs the weight threshold decoding of the demodulated signal, and outputs a decoding result. The method can system can achieve double functions of communication and light modulation control, achieve the systematic and structural design of a codeword set, and can further improve the transmission performances while reducing the operation complexity.

Description

technical field [0001] The present application relates to the technical field of visible light communication, in particular to a coding-based dimming control method and system for visible light communication. Background technique [0002] Visible light communication system has dual functions of communication and lighting. It needs to take into account the quality of light while ensuring reliable transmission of information. For this reason, organically combining visible light communication technology with dimming control technology to realize a visible light communication system that is green, energy-saving, environmentally friendly, and adaptable to the needs of different lighting conditions in different occasions has great development potential and application prospects, which has also been written In the protocol of IEEE 802.15.7. [0003] At present, when dimming visible light communication, there are mainly inter-code complement schemes, intra-code complement schemes, ...

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Problems solved by technology

Among them, both the inter-code complement scheme and the intra-code complement scheme have the advantages of easy operation, low complexity, channel coding, and no chroma drift. However, due to the decrease in data rate and low spectral efficiency due to complement code, In addition, the dimming accuracy of the intra-code scheme is limited by the minimum pulse width

[0004] The amplitude changing scheme is simple and easy to operate, but it will cause chromaticity drift and cannot accurately control the brightness of the LED; the biggest advantage of the frequency changing scheme is that its spectral efficiency is higher than other schemes, but it also has high complexity , Difficult to operate, unable to perform channel coding, and lack of fast coding / decoding schemes

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