Title :
50-Mb/s diffuse infrared free-space link using on-off keying with decision-feedback equalization
Author :
Marsh, Gene W. ; Kahn, Joseph M.
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., California Univ., Berkeley, CA, USA
Abstract :
We report an experimental 50-Mb/s free-space infrared link for indoor wireless communication, which achieves low bit-error rates (BERs) in the presence of multipath distortion, shadowing, and ambient natural and artificial lighting. The eye-safe 806 nm transmitter, directed at the ceiling, emits an on-off-keyed signal having 475-mW average power. The receiver employs a 1-cm/sup 2/ Si p-i-n photodiode coupled to a high-index hemispherical concentrator, which is covered by an optical bandpass filter of 30-nm bandwidth. A decision-feedback equalizer mitigates the effect of multipath ISI. In the presence of bright skylight, the link achieves a range of 2.9 m at 10/sup -7/ BER.<>
Keywords :
digital communication systems; equalisers; error statistics; optical links; optical receivers; p-i-n photodiodes; 475 mW; 50 Mbit/s; 806 nm; BER; IR digital link; Si; ambient natural lighting; artificial lighting; bit-error rates; decision-feedback equalization; decision-feedback equalizer; diffuse infrared free-space link; high-index hemispherical concentrator; indoor wireless communication; multipath ISI; multipath distortion; on-off keying; optical bandpass filter; p-i-n photodiode; receiver; shadowing; transmitter; Bit error rate; Optical coupling; Optical distortion; Optical fiber communication; Optical receivers; Optical transmitters; PIN photodiodes; Shadow mapping; Stimulated emission; Wireless communication;
Journal_Title :
Photonics Technology Letters, IEEE
