scholarly journals Analysis and Compensation of Chromatic Dispersion in Long-hauls Optical Coherent System

2021 ◽  
Author(s):  
Narimane Hadjadji ◽  
Rachid Hamdi
Keyword(s):  
Dispersion Compensation ◽  
Chromatic Dispersion ◽  
Optical Systems ◽  
Coherent System ◽  
Phase Shift Keying ◽  
Transmission Distance ◽  
Quadrature Phase ◽  
Shift Keying ◽  
Simulation Results ◽  
Electronic Dispersion

In this paper, we demonstrate the efficiency of Electronic Dispersion Compensation (EDC) for coherent optical systems based on Polarization Division Multiplexed Quadrature Phase Shift Keying (PDM-QPSK). The performance of the proposed system is tested using a pulse that has been recently used in the presence of nonlinear effects.The proposed system is compared to the 0.3RZ-PDM-QPSK system at the optimum launched power under different symbol-rates and lengths of transmission. The simulation results confirm that the proposed method enhances the system performance. In addition, it secures a low penalty that is below 0.6 dB. As a result, the feasible transmission distance is improved by 29 %, 20.15 %, and 26.7 %, at 14 GBaud, 28 Gbaud, and 56 Gbaud, respectively.

Dispersion Compensation for High-Speed and Long-Distance Transmission of CSRZ-DQPSK Optical Signal

2015 ◽  
Vol 36 (1) ◽  
Author(s):  
Dejun Feng ◽  
Peipei Zhang ◽  
Guanxiu Liu ◽  
Dongfang Jia
Keyword(s):  
High Speed ◽  
Dispersion Compensation ◽  
Optical Signal ◽  
Coded Modulation ◽  
Phase Shift Keying ◽  
Long Distance ◽  
Quadrature Phase ◽  
Shift Keying ◽  
Modulation Signal ◽  
Electronic Dispersion

AbstractThis paper compares the performances of 100 Gbit/s carrier-suppressed return-to-zero differential quadrature phase shift keying coded modulation signal through 3,600 km both in optical and photoelectric dispersion compensation schemes. Different dispersion compensation fiber methods are adopted in optical compensation while the photoelectric compensation is the combination of electronic dispersion compensation and optical compensation. It is shown that pre-compensation of DCFs and mixed (pre- and post-) compensation of DCFs are more excellent than the other two schemes in optical compensation, corresponding to mixed (pre- and post-) compensation of DCFs method, while pre-compensation of DCFs method is the best strategy in photoelectric compensation.

scholarly journals Reduced-Complexity Multiple-Symbol Detection of O-QPSK Signals in Smart Metering Utility Networks

Electronics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2049
Author(s):  
Congyu Shi ◽  
Gaoyuan Zhang ◽  
Haiqiong Li ◽  
Congzheng Han ◽  
Jie Tang ◽  
...  
Keyword(s):  
Detection Performance ◽  
Smart Metering ◽  
Phase Shift Keying ◽  
High Complexity ◽  
Observation Window ◽  
Slow Fading ◽  
Symbol Detection ◽  
Quadrature Phase ◽  
Shift Keying ◽  
Simulation Results

In this work, an implementation-friendly multiple-symbol detection (MSD) scheme is proposed for the IEEE 802.15.4g offset quadrature phase shift keying (O-QPSK) receivers over the slow fading channel. The full MSD scheme presents better detection performance than the symbol-by-symbol detection (SBSD) scheme, yet its complexity increases exponentially as the observation window length increases. We introduce a simplified MSD scheme based on two powerful strategies. We first seek the optimal and suboptimal decisions in each symbol position with the standard SBSD procedure. Then, the aforementioned optimal and suboptimal decisions instead of all candidates are jointly searched with the standard MSD procedure. That is, only the most and second most reliable candidates in each symbol position are selected to participate in the final detection. The simulation results demonstrate that the new MSD scheme can achieve more encouraging energy gain than the SBSD scheme, while the high complexity of full MSD is also effectively reduced. A more legitimate compromise between detection performance and complexity is thus accomplished, which enables smart metering utility networks (SUN) nodes to achieve energy saving and maximum service life.

scholarly journals A Pan-Function Model for the Utilization of Bandwidth Improvement and PAPR Reduction

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Yidong Xu ◽  
Wei Xue ◽  
Wenjing Shang
Keyword(s):  
Attenuation Factor ◽  
Average Power ◽  
Quadrature Modulation ◽  
Phase Shift Keying ◽  
Function Model ◽  
System A ◽  
Constant Envelope ◽  
Quadrature Phase ◽  
Shift Keying ◽  
Simulation Results

Aiming at the digital quadrature modulation system, a mathematical Pan-function model of the optimized baseband symbol signals with a symbol length of4Twas established in accordance with the minimum out-band energy radiation criterion. The intersymbol interference (ISI), symbol-correlated characteristics, and attenuation factor were introduced to establish the mathematical Pan-function model. The Pan-function was added to the constraints of boundary conditions, energy of a single baseband symbol signal, and constant-envelope conditions. Baseband symbol signals with the optimum efficient spectrum were obtained by introducing Fourier series and minimizing the Pan-function. The characteristics of the spectrum and peak-to-average power ratio (PAPR) of the obtained signals were analyzed and compared with the minimum shift keying (MSK) and quadrature phase-shift keying (QPSK) signals. The obtained signals have the characteristics of a higher spectral roll-off rate, less out-band radiation, and quasi-constant envelope. We simulated the performance of the obtained signals, and the simulation results demonstrate that the method is feasible.

scholarly journals An Accurate Modulation Recognition Method of QPSK Signal

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Yongxin Feng ◽  
Zhenyu Teng ◽  
Fanwei Meng ◽  
Bo Qian
Keyword(s):  
Communication Systems ◽  
Signal Classification ◽  
Signal Recognition ◽  
Phase Shift Keying ◽  
Modulation Recognition ◽  
Recognition Method ◽  
Space Condition ◽  
Quadrature Phase ◽  
Shift Keying ◽  
Simulation Results

Quadrature phase shift keying (QPSK) modulation has been widely applied in communication systems. With the increasing development of QPSK modulation recognition, it is meaningful for ensuring validity and accuracy of recognition method. Therefore, the method of signal recognition has been presented based on the features of QPSK modulated signal, in which the feature parameters of QPSK signal are extracted. Besides, signal classification is fulfilled through thresholds, and modulation recognition is completed with quartic spectrum. The simulation results show that, the method can recognize QPSK modulation effectively in less sample space condition and can be more accurate.

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