Visible light voice intercom system based on MIMO technology

Abstract

The invention discloses a visible light communication two-way voice intercom system based on the MIMO technology. The system comprises a transmitting end and a receiving end, the transmitting end comprises an audio encoding module, a power divider, a modulation module, a first LED driving module and an LED array, which are connected in sequence; and the receiving end comprises a PD array, a second LED driving module, a RSSI indication circuit, a demodulation module and an audio decoding module, which are connected in sequence. In the visible light communication two-way voice intercom system disclosed by the invention, LED lamps in the LED array and the PDs in the PD array are separated from each other at equal angles and are uniformly distributed on the horizontal plane, so the shortcomings of poor diffraction capability in visible light communication can be compensated. When in use, the LED array of an A communication end is opposite to the PD array of a B communication end, and the PD array of the A communication end is opposite to the LED array of the B communication end, in this way, the PD arrays and the LED arrays of the A communication end and the B communication end can realize the normal communication of the receiving end and the transmitting end in an NLOS scene, and the voice intercom function of the both communication parties in the NLOS scene is satisfied.

Description

technical field [0001] The present invention relates to visible light communication technology, in particular to a visible light voice communication system based on MIMO technology. Background technique [0002] With the advent of the mobile Internet era, various new content and new applications have sprung up, smart mobile terminals have become popular all over the world, and the number of mobile users and data traffic have shown explosive growth. Radio frequency communication will face severe spectrum shortage, so it is urgent to open up new spectrum to fundamentally solve the contradiction between the demand for ultra-large-capacity communication and the spectrum crisis. Visible light communication has unique advantages over radio frequency communication. First, the area coverage and directional transmission of visible light signals can allow adjacent beams to cross without affecting each other, thereby minimizing mutual interference, but mutual interference between adjac...

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Problems solved by technology

[0005] However, visible light communication cannot replace radio frequency communication, and it has the following disadvantages: First, visible light travels along a straight line, and its diffraction ability is very poor. Most of them can only communicate in line-of-sight scenarios, and cannot communicate normally in non-line-of-sight scenarios

In addition, the attenuation rate of electromagnetic waves in free space is inversely proportional to the square of its frequency. Due to the high frequency and fast attenuation speed of visible light, long-distance communication cannot be realized, which greatly limits its application.

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