Abstract
In this paper we demonstrate a new technology in which we use the spatial optical modulation with trigger pulse width and pulse width modulation of light source (LED,LD) to build the near-infrared electro-optics modulation coding system (NIEOMCS). Using the optical coupler to let the pulse modulation near infrared LED collimated light of transmitter enter into an optical fiber and spatial optical modulator, the electro-optics modulation signal is then detected by the photodiode of the receiver. Because of aperture module with three changeable stop sizes and three duty cycles of light signal, there are 27 kinds of code modes in this system. When the receiver aperture is smaller than the correlation length of fading and the observation interval is shorter than the correlation time of fading, the modulation code error rate of the modulation system occurring is less than 0.2%.
Publisher
Trans Tech Publications, Ltd.
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