Dual wavelength optical fiber HDTV distribution networks using self-synchronization technique and multistar topology

A new optical fiber time-division multiple-access (TDMA) network is proposed for HDTV distributions. It uses two wavelengths to carry optical TDMA and clock signals through the common fibers to each subscriber. At the receiver, both signals are easily separated by using a wavelength division multiplexing (WDM) demultiplexer, and therefore, the frame and time-slot synchronizations are feasibly achieved by using optical fiber delay lines to independently process the separated clock and TDMA signals. This self-synchronization characteristic can be used to improve the network flexibility, which allows one to build a large-scale HDTV distribution network based on a multistar topology. Furthermore, a sensitivity analysis of optical TDMA receivers is carried out. It is shown that, compared with a point-to-point optical fiber digital system, the multi-user optical TDMA system requires a lower extinction ratio to alleviate the performance degradation