Direct modelling of error statistics at 40 Gbit/s rate in SMF/DCF link with strong bit overlapping

Efficient weakly-constrained codes for mitigation of patterning effects in Digital Communications

“…Recent investigations dedicated to data transmission through optical channels [9,10] indicate that patterning effects take place in optical lines of various structure. For example, in [9] the WDM RZ-DBPSK SMF/DCF channel with hybrid Raman/EDFA amplification was examined.…”

“…In [10] a transmission line using the OOK format is described. As shown in [10], the OOK format leads to error statistics in which the 101 triplet error probability is at least 10 times the error probability of any of the other triplets.…”

“…Channel preencoding has already been considered for mitigation of channel impairments (see e.g. [4][5][6][7][8][9][10][11]) in high-bit-rate systems. In particular, suppression of ICFWM effects by using certain modulation codes was proposed in [5].…”

Upgrading Legacy Long-Haul WDM Systems Through Unbalancing the Proportion of 1s and 0s in the Transmitted Data

“…This, in fact, can be the ideal proportion of the 1s and 0s in transmission [1]. However, it has already been shown that in some systems, particular bit sequences can result in a worse performance than others due to some effects such as intersymbol interference (ISI) and nonlinearities [2]. Theoretically, the use of 50% 1s and 0s can be the ideal selection for systems which operate in the linear regime, assuming that the system performance is dominated by noise in the electrical receiver which simply adds equally to the 1s and 0s.…”

The analysis of the error statistics in a 5 × 40 Gbit/s fibre link with hybrid amplification

“…The on-off-keying format (OOK) in high-bitrate transmission is limited by the effects of intra-channel four-wave-mixing (ICFWM), which generates "ghost" pulses [2]- [3]. This is an important example of patterning in optical channels [4], which in digital communication is seen as dependency of the single-bit error probability on the surrounding bits. As another example of the same, we cite the patterning effects caused by the saturation of a semiconductor optical amplifier gain (see [5,6]).…”