Outdoor visible light communication receiving end natural background light filtering method

Abstract

The invention discloses an outdoor visible light communication receiving end natural background light filtering method. The method comprises the following steps: step one, analyzing the spectrum characteristic of a white-light LED and the spectrum characteristic of sunshine, and according to a comparison result between the spectrum characteristic of the white-light LED and the spectrum characteristic of the sunshine, selecting an induced transmission optical filter; step two, designing the structure of the optical filter in the step one, wherein the optical filter is composed of a plurality layers of films; step three, according to a relation between an incident angle forms when light is incident to the optical filter and the passband of the optical filter, obtaining an optimum incident angle theta of incident light through an analysis, and bringing forward the concept of light angle selector, wherein theta is greater than and equal to 0 degree and is smaller than and equal to 10 degrees; and step four, designing an optical filter and carrying out noise filtering, wherein the optical filter is composed of an incident light angle selector, the optical filter, a focusing lens and a photoelectric detector. The filtering method brought forward by the invention can effectively filter back ground light, brings forward that the optimal incident angle theta of the incident light is greater than and equal to 0 degree and is smaller than and equal to 10 degrees, reduces the deformation degree of the passband shape of the optical filter along with the change of theta, and guarantees the communication quality.

Description

technical field [0001] The invention belongs to the field of visible light wireless communication technology, optical filtering technology, and visible light communication technology of LED lamps between mobile vehicles, and in particular relates to a natural background light filtering method of an outdoor visible light communication receiving end. Background technique [0002] Visible Light Communication technology (VisibleLightCommunication, VLC) refers to the use of light in the visible light band as an information carrier, without using optical fiber and other wired channel transmission media, and a communication method that directly transmits optical signals in the air. LED car lights have the characteristics of high efficiency, low energy consumption, long life, environmental protection, high brightness and high temperature resistance, small size, and good stability. The flickering pulse light intensity modulation that cannot be sensed realizes the purpose of communica...

AI Technical Summary

Problems solved by technology

[0009] In order to solve the problem that outdoor visible light communication signal light and sunlight spectrum overlap more, resulting in the decrease of the signal-to-noise ratio at the receiving end, and the difficulty of separating the signal and noise, the present invention carefully analyzes the solar spectrum and the automobile LED headlight spectrum. Based on the similar and non-similar areas between them and the bandwidth relationship between the two, a natural background light filtering method at the receiving end of outdoor visible light communication is proposed at the front end of the receiving end. The filtering method designed in the present invention The optical filter can filter out the solar background light in non-similar areas, filter out the signal light in similar areas, and retain as much signal light bandwidth as possible, improving the signal-to-noise ratio

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