The duobinary optical transmission for high capacity systems

The authors present duobinary optical transmission, as an alternative to binary, for very high speed systems. There are three important advantages of this signalling format. The first is that the dispersion limited transmission distance over nondispersion shifted fibre (NDSF) is substantially increased due to the halving of the transmitter bandwidth. Secondly the constraints of high speed operation for the terminal equipment is significantly reduced due to its lower bandwidth characteristic. Finally the amount of signal processing required for duobinary operation is low, being readily achievable for engineering applications. They detail methods required to realise practical duobinary optical transmission and present results at 10 Gbit/s over NDSF. Implementation issues of this technique in high speed transmission are also addressed