Performance analysis of 112 Gb/s PDM-DQPSK optical system with frequency swept coherent detected spectral amplitude labels

In this paper, we present the performance analysis of 112 Gb/s polarization division multiplexed-differential quadrature phase shift keying (PDM-DQPSK) optical label switching system with frequency swept coherent detected spectral amplitude code labels in simulation. In this system, the payload consists of two 28 Gbaud channels which are orthogonally polarized. Direct detection is selected to demodulate the PDM payload in the receiver. 4 bits of 156 Mb/s spectral amplitude code label are frequency-swept coherently detected. The label and payload signal performances are assessed by the eye diagram opening factor (EOF) and bit error rate (BER) as function of received optical power (ROP) and optical signal to noise ratio (OSNR). We optimized the payload laser linewidth as well as the frequency spacing between the payload and labels likewise frequencies between the labels. For back-to-back system and 120 km transmission, label eye opening factors are 0.93 and 0.90 respectively, while payload optical signal-to-noise ratio is 23.4 dB and the payload received optical power is -13.3 dBm for a bit error rate of 10^-9. The payload could well be demodulated after 900 km transmission at a BER of 10^-3 using forward error correction (FEC).