LEDs (light emitting diodes) can be applied in both illumination and communication. A system of maritime
wireless communication with ships based on LED beacons is proposed in this paper. The communication space model
and optical transmission model were set up, visible wireless communication manner was analyzed. An anti-fading
method combining space and time diversity is adopted due to quick signal attenuation and large noise from nature light
interference. After filtering and judgment, the received diversity signals are separated to do bit comparison using
Hamming Perception Network. Through analysis and simulation, compared to ordinary space diversity or time diversity
way, this kind of anti-fading method can increase reliable communication distance greatly, reduce equipment cost and
improve bandwidth utilization rate.
White LED (light emitting diode) offer advantageous such as high brightness, lower power consuption and long life
spand, and is expected to be the next generation of lamp. The other merits of LED are high sensitivity and fine
modulation performance. An indoor optical wireless communication system is propsed and three kind of modulation
schemes are compared in band requirement and power requirement. Nine LED lights are installed in the different of the
room celling, so the RMS (root-mean-square delay spread) delay is also consided in hight bit rate enviroment, the
power loss and BER are presented under different time delay. The simulation results show that, the MPPM is bandwidth
efficeient than PPM and OOK. At the condition of high bit rate, MPPM performance much better than OOK and PPM
with low BER.