scholarly journals Coherent Magneto-optomechanical Signal Transduction and Long-Distance Phase-Shift Keying

2019 ◽  
Vol 12 (3) ◽  
Author(s):  
M.J. Rudd ◽  
P.H. Kim ◽  
C.A. Potts ◽  
C. Doolin ◽  
H. Ramp ◽  
...  
Sensors ◽  
2019 ◽  
Vol 19 (8) ◽  
pp. 1938 ◽  
Author(s):  
Haiyuan Wang ◽  
Hongxian Tian

Low-Power Wide-Area Network (LPWAN) is the technology that the Internet-of-Things (IoT) uses in long-distance, wide-coverage scenarios. As one of the ultra-narrowband (UNB) modulation techniques, M-ary position phase shift keying (MPPSK) modulation can provide high coverage and high reliability for LPWAN. This paper proposes a multipath separation method based on MPPSK modulation, which aims to eliminate the influence of multipath on the main path without increasing the spectrum overhead and system complexity. Specifically, the modulation parameter of the system is adjusted according to the delay value, so that the phase jump of the multipath signal falls outside the phase jump of the main path symbol to achieve separation of the multipath from the main path. Moreover, a normalized symbol joint decision method is proposed in order to reduce the introduced noise while using multipath information for decisions. The simulation results indicate that the multipath separation conditions given in this paper can meet the requirements of multipath separation of MPPSK signals. Compared with the existing mainstream decision scheme, the normalized symbol joint decision improves the demodulation performance of the system.


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.    


2016 ◽  
Vol 37 (4) ◽  
Author(s):  
Manisha Bharti ◽  
Ajay K. Sharma ◽  
Manoj Kumar

AbstractThis paper focuses on increasing the number of subscribers in optical code-division multiple access (OCDMA) system by using one of the features of light signal that it can be propagated in two polarization states. The performance of two-dimensional (2D) OCDMA system based on wavelength-time coding scheme by adding polarization state is investigated at varying data rates from 1 GHz to 6 GHz and for various modulation formats. It is reported that with increase in data rate of system, the performance of the system deteriorates due to polarization mode dispersion. Non-return to-zero (RZ), return to-zero (RZ), carrier suppressed return-to-zero (CSRZ) and differential phase shift keying (DPSK) modulation formats are simulated for a single user system with polarization. Investigations reveal that differential phase shift keying (DPSK) modulation format suits best to the proposed system and exhibit the potential to improve the flexibility of system for more number of users. The investigations are reported in terms of Q-factor, BER, received optical power (ROP) and eye diagrams.


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