DQPSK modulation for robust optical transmission

Abstract

The feasibility of long-haul transmission using differential quadrature phase shift keying (DQPSK) modulation is discussed. We focus in particular on the trade-off between spectral efficiency and reach in optical transmission systems using DQPSK modulation.

100GbE: QPSK versus OFDM

“…Both at 40-Gb/s [14,15] and 100-Gb/s [2,4] similar BER sensitivities have been reported for single carrier and OFDM transmission systems. The OSNR sensitivity for coherently detected systems is for a fixed gross data rate independent of the number of subcarriers that is used.…”

“…PMD, however, causes depolarization as well, thus in order to realize a large PMD tolerance a polarization diverse receiver is required. It has been shown that in combination with a polarization diverse receiver both single carrier [14] and multi-carrier (OFDM) [15] systems can offer a practically unlimited tolerance towards PMD.…”

Coherent spectral amplitude coded label detection for DQPSK payload signals in packet-switched metropolitan area networks

“…In order to focus on the label detection performance, the measurement of BER for DQPSK payload are omitted as the performance of this modulation format is well documented in the literature [9], however we checked and successfully verified that the DQPSK payload signal was error-free for both power profiles for OSNR values cases. Fig.…”

The impact of parametric noise amplification on long haul transmission throughput

“…In numerical simulations, OPC offers the best SNR of the techniques considered; this is because midpoint OPC splits the link in two, reducing the quadratic growth of parametric noise amplification, and halving the length over which the signal polarisations are decorrelated. In this section, we briefly review progress in OPC device and system development, concentrating on systems employing coherent detection [22]. OPCs have been fabricated from a wide variety of materials including fibre [23][24][25][26][27][28], bulk [29] and quantum dot [30] semiconductor optical amplifiers, periodically poled lithium niobate (PPLN) [31], silicon [32], soft glass [33] and using opto-electronic devices [34].…”