Duobinary encoded polarization shift keying (PolSK) modulation in long-haul optic transmission

2004 ◽  
Author(s):  
Jiayu Fan ◽  
Zhaoming Huang ◽  
Lutang Wang
2019 ◽  
Vol 4 (2019) ◽  
pp. 43-49
Author(s):  
Diptangshu Chattopadhyay ◽  
Manisha Bharti

Free Space Optical (FSO) communication is a quickly developing technology that is designed to handle high data rates while maintaining a good quality factor (Q-factor). Many novel techniques have been implemented to cope with atmospheric attenuating factors, such as fog and rain. Here, we have introduced circular polarization shift keying (C-PolSK) modulation to produce a stable and uniform light beam. The plane of polarized light keeps rotating along with the propagation vector, which helps reduce phase variations and cross-channel effects. C-PolSK provides higher penetrating power and attenuation resistance over linear polarization shift keying (L-PolSK). Two different C-PolSK models have been proposed and graphical comparisons, relying on such parameters as Q-factor, transmission distance and inputoutput power, have been made. The cases of moderate fog and rain attenuation are taken to verify the model’s efficiency. Polarized light is split into two orthogonal components and then modulated using the Mach-Zehnder modulator. One of the models also employs the principle of orthogonal differential phase shifting. Eye diagrams have been provided to verify the bit error rate (BER). The orthogonal differential phase shifted C-PolSK model proves to be the most suitable implementation prototype.


2020 ◽  
Vol 17 (2) ◽  
pp. 171-186
Author(s):  
Jelena Todorovic ◽  
Branimir Jaksic ◽  
Petar Spalevic ◽  
Djoko Bandjur ◽  
Milos Bandjur

In this paper, the quality of the Polarization Shift Keying (PolSK) modulated signal in a Free Space Optical (FSO) system is analyzed. The atmospheric channel is statistically modeled with four different distributions, namely, the Gamma-Gamma distribution, Negative Exponential distribution, Kdistribution, and I-K distribution. For all four channel models, the Average Bit Error Rate (ABER) at the receiving side of the system is determined in an analytically closed form. The results are graphically presented and discussed in order to determine the impact of certain parameters on the ABER, i.e., the quality of the received signal in the PolSK modulated FSO system. These parameters are the Signal-to-Noise Ratio (SNR), the FSO link distance, the wavelength at which the signal is transmitted, and the atmospheric turbulence strength.


2019 ◽  
Vol 7 (1) ◽  
pp. 30-39
Author(s):  
Fatima faydhe Al- Azzawi ◽  
Faeza Abas Abid ◽  
Zainab faydhe Al-Azzawi

Phase shift keying modulation approaches are widely used in the communication industry. Differential phase shift keying (DPSK) and Offset Quadrature phase shift keying (OQPSK) schemes are chosen to be investigated is multi environment channels, where both systems are designed using MATLAB Simulink and tested. Cross talk and unity of signals generated from DPSK and OQPSK are examined using Cross-correlation and auto-correlation, respectively. In this research a proposed system included improvement in bit error rate (BER) of both systems in  the additive white Gaussian Noise (AWGN) channel, by using the convolutional and block codes, by increasing the ratio of energy in the specular component to the energy in the diffuse component (k) and  the diversity order BER in the fading channels will be improved in both systems.    


2020 ◽  
Vol 10 (6) ◽  
pp. 902-908
Author(s):  
Syed Zahiruddin ◽  
Avireni Srinivasulu ◽  
Musala Sarada

Objective: The interest concern towards the development of enabling technology towards new current mode devices has forced the designers and researchers for the invention of devices, which has having the characteristics like such as low power, robustness, compactness, efficiency and scalability. Methods: Second Generation Current Controlled Conveyor (CCCII) is the prevailing current mode device of the times today. Since its invention by A. Fabre, it has prominent applications in the field of analog signal processing and in biomedical applications too. In this manuscript, CCCII is used as an enabling device to design a Frequency Shift Keying (FSK) Generator. Results: The proposed topology is designed using a single active device CCCII with least passive components. The circuit enjoys the features of like electronic tunability of frequency using the bias current. Conclusion: It can be concluded that the FSK generator circuit designed using single CCCII confers better results in contrast to the existing structures. The maximum power consumption is 0.196 mW. The proposed circuit has the benefit of simple configuration, which is very much proficient for IC fabrication.


Author(s):  
M. E. Shevchenko ◽  
A. V. Gorovoy ◽  
S. N. Solovyov

The paper considers the spatial filtering methods of signals with spectrum overlapping under conditions of a priori uncertainty of the directions of arrival from radio sources. The estimates of the directions of signals arrival obtained by ESPRIT or MUSIC are used in order to build a spatial filter. It is shown that when using ESPRIT, unlike MUSIC, an additional calculations of filter coefficients based on estimates of the directions of signals arrival are not required, and the quadrature components of the signals are formed simultaneously with estimates of the direction of their arrival. The probability of error performances of minimum shift keying signals which were divided by spatial filtering on the basis of ESPRIT and MUSIC using seven-element circular and angular antenna arrays are given.


2021 ◽  
pp. 1-1
Author(s):  
Alexandros E. Tzikas ◽  
Panagiotis D. Diamantoulakis ◽  
George K. Karagiannidis

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