IOSR Journal of Electronics and Communication Engineering (IOSR-JECE) e-ISSN: 2278-2834,p- ISSN: 2278-8735.Volume 11, Issue 4, Ver. II (Jul.-Aug .2016), PP 36-42 www.iosrjournals.org DOI: 10.9790/2834-1104023642 www.iosrjournals.org 36 | Page Analysis and Execution of 80 Gb/s PDM-DQPSK Optical Label Switching System with SAC Labels Aboagye Adjaye Isaac 1 , Cao Yongsheng 2 , Chen Fushen 3 1 (Communication and Information Engineering UESTC, Sichuan, China) 2 (Communication and Information Engineering UESTC, Sichuan, China) 3 (Communication and Information Engineering UESTC, Sichuan, China) Abstract: We present the performance of 80 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. 4 bits of 156 Mb/s spectral amplitude code (SAC) 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). For back-to-back system and 138 km transmission, label eye opening factors are 0.94 and 0.86 respectively, while payload optical signal-to-noise ratio is 25.6 dB and the payload received optical power is -12.6 dBm for a bit error rate of 10 -9 . The payload could well be demodulated after 1,260 km transmission at a BER of 10 -3 using forward error correction (FEC). Keywords: Coherent detection, optical label switching (OLS), polarization division multiplexed (PDM), polarization mode dispersion (PMD), spectral amplitude code (SAC). I. Introduction Optical communication has become one of the most important parts in modern communications due to the explosive growth of Internet data and services, and its developing direction is all-optical network (AON), with high-capacity and broad bandwidth. One optical technique used to improve the efficiency of optical communication systems is polarization division multiplexing (PDM). PDM serves to double the data rate using field-proven formats, Combined with differential quadrature phase shift keying (DQPSK), four bits are transmitted per symbol. The main challenge of this format is, however, to provide a precise and fast polarization tracking [1-3]. POLMUX implies a higher sensitivity to polarization effects, such as polarization mode dispersion (PMD) and polarization dependent loss (PDL). With respect to the single polarization case, penalties arise from PMD and PDL-induced crosstalk between the demultiplexed channels and from OSNR degradation by PDL [4–6]. Optical label switching (OLS) technique is considered a way to increase transmission speed in optical networks [7]. OLS beats the electronic bottleneck of system switches and disposes off optical-electronic- optical change to diminish the transmission delay. A straightforward and robust way of creating optical labels is the use of spectral tones [8, 9]. We introduce a SAC label detection system based on optical coherent detection, which produces an electronic signal that can be shaped into a control signal for an optical switching fabric by applying digital signal processing (DSP) algorithms. SAC has been applied in optical code division multiple access (OCDMA) and spectral code labeled systems [10, 11]. In this paper, we build a robust long haul transmission system to evaluate the transmission performance of 80 Gb/s PDM-DQPSK SAC label switching system in simulation using polarization tracker to recover the orthogonal polarization state of the PDM payload signal in order to mitigate the effects of polarization mode dispersion (PMD) and polarization dependent loss (PDL). We employed a novel method of frequency-swept coherent detection to decode SAC label, which reduces the complexity of label decoder. The high speed Payload is directly detected [12-15], which gets rid of complicated digital signal processing (DSP) procedure [16, 17]. The remaining parts of the paper are organized as follows. Section 2 provides a description of the operational principles of our proposed frequency-swept coherent detection for SAC labels. The simulation setup of SAC labelling scheme for 80 Gb/s PDM-DQPSK SAC label system with polarization tracker is presented in section 3. In section 4, the simulation result is presented and analyzed. We conclude the paper in section 5. II. Principle of Frequency-Swept Coherent Detection Coherent detection allows the greatest flexibility in modulation formats, as information can be encoded in amplitude and phase, or alternatively in both in-phase (I) and quadrature (Q) components of a carrier. The receiver exploits knowledge of the carrier's phase to detect the signal. In a SAC label framework, SAC label and payload occupy the same time space however different wavelengths. Labels are encoded in wavelength domain,