We present a simple precoder for optical duobinary transmission without the need for an external feedback tap. By avoiding this external feedback tap we are able to overcome the speed limit imposed by high speed data transmission affecting all previously published approaches [5, 6]. The hardware implementation of the proposed precoder is realized using standard logic ICs, in our case operating at 10 Gbit/s. We show experimentally that error free duobinary transmission with long PRBS sequences (2 23 - 1) is possible. Using our simple precoder and a duobinary filter as an encoder enables the conversion of a standard binary transmission scheme into a duobinary transmission scheme as an add-on feature. Since standard logic ICs are used, a precoder upgrade to 40 Gb/s can be done in a straightforward way.
[2]
Katsumi Emura,et al.
Characteristics of optical duobinary signals in terabit/s capacity, high-spectral efficiency WDM systems
,
1998
.
[3]
S. Kuwano,et al.
Dispersion-tolerant optical transmission system using duobinary transmitter and binary receiver
,
1997
.
[4]
L. Pierre,et al.
The phase-shaped binary transmission (PSBT): a new technique to transmit far beyond the chromatic dispersion limit
,
1997,
IEEE Photonics Technology Letters.
[5]
Y. Kisaka,et al.
Differential precoder IC modules for 20-and 40-Gbit/s optical duobinary transmission systems
,
1999,
IMS 1999.