Wireless access over optical fibre: from cellular radio to broadband; from UHF to millimetre-waves

In a wireless over fibre system signals are carried over optical fibre in their modulated form between a central site and the base-stations. Base-station functionality from fibre to antenna for the down-link/up-link is reduced to photodetection/modulation, amplification and, in some cases, frequency conversion. This greatly simplifies the base-stations and makes it easy to carry signals of different modulation formats over a common fibre infrastructure. Changes in the range of services carried can be made at the central site, and modulation/demodulation, switching and other resources can be shared dynamically between base stations, leading to further economies. In this paper recent work on wireless over fibre systems at UCL is presented, with emphasis on systems for broadband applications.