scholarly journals Estimation of signal reception probability characteristics using models of fading transionosphere channels

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
L.E. Nazarov ◽  
◽  
V.M. Smirnov ◽  
Keyword(s):  
Phase Shift ◽  
Distribution Density ◽  
Empirical Distribution ◽  
Phase Shift Keying ◽  
Digital Signals ◽  
Rician Distribution ◽  
Spatial Fluctuations ◽  
Shift Keying ◽  
Temporal And Spatial ◽  
Signal Fading

Statistical models of narrow-band transionosphere channels, which determine the occurrence of signal fading due to random temporal and spatial fluctuations of the electron density of ionospheric irregularities, are considered. Fading models are based on the use of empirical relationships with respect to the distribution density of the amplitude of the signals at the output of the transionosphere channel as a random process. The parameters of empirical distribution densities (lognormal distribution, m-Nakagami distribution, Rician distribution) are related to the scintillation coefficient of signal fading. Using the considered models of signal fading, a technique is presented for estimating the probability of erroneous reception of digital signals with phase shift keying during reception. Using this technique, estimates of energy losses with respect to propagation in free space were made, reaching 0.001 for a scintillation coefficient value of 0.5 to 3 dB for signals with 2- and 4-phase shift keying.

Statistical models of fading signals propagated through the ionospheric satellite channels

2021 ◽  
Author(s):  
V.V. Batanov ◽  
L.E. Nazarov
Keyword(s):  
Statistical Models ◽  
Scintillation Index ◽  
Phase Shift Keying ◽  
Digital Signals ◽  
Radio Channels ◽  
Spatial Fluctuations ◽  
Shift Keying ◽  
Satellite Channels ◽  
Phase Variations ◽  
Temporal And Spatial

Statistical models of satellite ionospheric radio channels are considered in the article, the influence of which causes fading of signals during their propagation (amplitude and phase variations of signals) due to random temporal and spatial fluctuations of the electron density of ionospheric irregularities. These models are based on the use of empirical laws regarding the densities of the amplitudes and phases of digital signals from the output of signal demodulators. A technique for estimating the probability of erroneous reception of digital signals with phase shift keying using the considered fading models is presented. Estimates of energy losses end errorperformance degradation during propagation along ionospheric satellite radio channels with scintillation index parameters typical for the P- and L-frequency bands, with respect to propagation in free space, have been made.

Performance Comparison between DPSK and OQPSK modulation approaches in multi environments channels with Matlab Simulink models

2019 ◽  
Vol 7 (1) ◽  
pp. 30-39
Author(s):  
Fatima faydhe Al- Azzawi ◽  
Faeza Abas Abid ◽  
Zainab faydhe Al-Azzawi
Keyword(s):  
Phase Shift ◽  
Fading Channels ◽  
Additive White Gaussian Noise ◽  
Block Codes ◽  
Performance Comparison ◽  
Phase Shift Keying ◽  
Differential Phase Shift ◽  
Matlab Simulink ◽  
Communication Industry ◽  
Shift Keying

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.    

Design and Performance Analysis of 2D OCDMA System with Polarization States

2016 ◽  
Vol 37 (4) ◽  
Author(s):  
Manisha Bharti ◽  
Ajay K. Sharma ◽  
Manoj Kumar
Keyword(s):  
Phase Shift ◽  
Polarization State ◽  
Phase Shift Keying ◽  
Modulation Formats ◽  
Differential Phase Shift ◽  
Differential Phase ◽  
Differential Phase Shift Keying ◽  
Shift Keying ◽  
Polarization States ◽  
Code Division Multiple

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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