Wireless In-House Data Communication via Diffuse Infrared Radiation

A novel wireless broadcast/multiaccess channel is described for flexibly interconnecting a cluster of data terminals located within the same room. The transmission medium is diffusively scattered infrared radiation at 950-nm wavelength. Transmission is low-to-medium speed and the range up to 5O m. Theoretical analysis indicates that the time dispersion limits the transmission bandwidth of the system to 260 Mbit -m/s, but background noise produced by ambient daylight reduces the transmission speed below 1 Mbit/s. The transmission properties of the diffuse optical channel are analyzed, and experimental digital links for baseband PCM at 125 kbit/s and PSK 64 kbit/s are demonstrated. © 1979 IEEE