16-10-2010, 02:19 AM
White LED (Light Emitting Diode) is expected to be the next generation of lamps due to its properties such as high brightness, reliability, low consumption and long life span. In this article , the proposed system for indoor optical wireless duplex channel communication system, as an access to the Internet, utilizing both white LED lights and infrared LEDs is described. The illuminance and power distribution, impulse response, and modulation techniques has been studied in this article. LED lights and receivers design strategies has also been discussed. A demonstration system could achieve a peak data rate of 64 Kbps for browsing the net. integrated dual functions of lighting and communication are performed by this.
Long life expectancy, high tolerance to humidity, low power consumption, low voltage and small size etc are the favorable qualities of white LED which is the reason why white LEDs are lights are gradually replacing the
traditional incandescent and fluorescent lamps. LEDs can also be modulated in high speed as a result of which it can be used for communication as well.
EMITTER DESIGN
there are 9 white LED lamps evenly
installed in the ceiling of the model room. The wavelength band between 780 and 950 nm is chosen for
the upward infrared page link due to the commercially availability of low cost LEDs. It is also at the peak responsivity of silicon photodiodes.
get the report here:
http://mediafirefile/x7c26i89wk8dgmk/Indoor%20Optical%20Wireless%20Communication%20System.pdf
