Performance comparison of 40G and 100G coherent PDM-QPSK for upgrading dispersion managed legacy systems

Mixed line rate virtual topology design considering nonlinear interferences between amplitude and phase modulated channels

“…The most well-known candidates are phase-shaped binary transmission (PSBT) [13,14], differential phase shit keying (DPSK) [13,15], partial DPSK (p-DPSK) [13,15], return-to-zero differential quaternary phase shift keying (RZ-DQPSK) [13,15]. In the last years, thanks to the successful development of the coherent technology and digital signal processing (DSP) two other modulation formats has been proposed, namely polarization-division multiplexed quaternary phase shift keying (PDM-QPSK) [13,15,16] and polarization-division multiplexed binary phase shift keying (PDM-BPSK) [17].…”

“…Considering the modulation formats here, the two candidates are as follows: PDM-QPSK [16] and frequency division multiplexed PDM-QPSK (FDM PDM-QPSK) [18].…”

Effect of multiplexer/demultiplexer bandwidth on upgrading current 10G to 40 G optical communication systems

“…The later technique can be achieved by increasing the number of wavelengths used on an existing wavelength plan with each wavelength having the same data rates or by using different data rate for the different wavelengths. Using different data rates in a system at different wavelengths is known as a hybrid communication system, which is also known a heterogeneous system [4]- [7]. Commercial DWDM systems are deployed initially with channels carrying lower data rate (10G), then upgraded using wavelengths carrying 40G data rate.…”

Transmission of 40×200 Gbit/s polarisation division multiplexed quadrature phase shift keyed channels over 6600 km

“…Introduction: Recent reports have shown the potential of polarisation division multiplexed quadrature phase shift keying (PDM-QPSK) associated with coherent receivers to reach transpacific distances [1] and to upgrade legacy networks [2]. At the same time, optical transport of per-channel bit rates beyond 100 Gbit/s is under active research.…”

“…Owing to polarisation scrambling, each recording corresponds to an arbitrary state of polarisation at the input of the link. Afterwards, the waveforms are processed offline in a computer, as in [2], providing the bit error ratio (BER) measurement, here with direct decoding. BER is subsequently converted into the Q 2 -factor.…”