Showing papers on "Optical Carrier transmission rates published in 1979"

Wireless in-house data communication via diffuse infrared radiation

Abstract: A novel wireless broadcast/multi-access 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 50 m. Theoretical analysis indicates that the time dispersion limits the transmission bandwidth of the system to 260 Mbit ċ 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.

Semiconductor laser sources for coherent optical-fibre systems

Abstract: Reliable detection of a phase-modulated optical carrier has been demonstrated over 500 m of graded-index optical fibre using a semiconductor-laser source and mode-mode interference. The system performance is limited by the noise and spectral properties of the optical source. Spectral measurements indicate that transmission over several kilometres should be possible. This has direct significance for amplitude-modulated systems with semiconductor-laser sources as it implies that modal noise can occur at fibre connections up to several kilometres from the optical source

Measurements performed on l.e.d. 4-level digital optical-fibre system for 68 Mbit/s

Abstract: A description is given of the configuration of a 4-level digital optical-fibre system. By means of light-emitting diodes (l.e.d.s), it is possible to transmit an equivalent bit rate of 68.736 Mbit/s (34.368 Mbaud), over a distance of 5.16 km, the signal/noise ratio required for a bit error rate (b.e.r.) of 10?9 being observed.