OPTICAL-FIBER TRANSMISSION OF A BROAD-BAND SUBCARRIER MULTIPLEXED SIGNAL USING PTM TECHNIQUES

Subcarrier multiplexing (SCM) is an attractive multiplexing technique to deliver broadband services over optical fibres. The majority of exi sting systems employ an analogue signal for optical transmission and t herefore the performance of these systems are limited. This paper prop oses to improve SCM system performance by converting the analogue SCM signal into a pulse time modulated signal for optical transmission. Th e pulse time modulation techniques investigated are pulse frequency mo dulation and square wave frequency modulation. System measurements and theoretical predictions were obtained and they are in close agreement . We have improved the dynamic range and optical power budget consider ably, compared to conventional systems.