scholarly journals Performance Analysis and Noise Immunity WiMax Radio Channel

10.5772/30357 ◽  
2012 ◽  
Author(s):  
Oleksii Strelnitskiy ◽  
Oleksandr Strelnitskiy ◽  
Oleksandra Dudka ◽  
Oleksandr Tsopa ◽  
Vladimir Shokalo
Keyword(s):  
Performance Analysis ◽  
Noise Immunity ◽  
Radio Channel

scholarly journals Optimal nonlinear filtering of M-PSK signals against a background of harmonic interference with a random initial phase

2021 ◽  
Vol 9 (6) ◽  
pp. 46-56
Author(s):  
G. V. Kulikov ◽  
Trung Tien Do ◽  
E. V. Samokhina
Keyword(s):  
Initial Phase ◽  
Nonlinear Filtering ◽  
Noise Immunity ◽  
Signal To Noise Ratio ◽  
Radio Channel ◽  
Complete Suppression ◽  
Two Phase ◽  
Probability Of Error ◽  
Useful Signal ◽  
Optimal Nonlinear Filtering

Objectives. The widespread use of radio data transmission systems using signals with multiposition phase shift keying (MPSK) is due to their high noise immunity and the simplicity of constructing the transmitting and receiving parts of the equipment. The conducted studies have shown that the presence of non-fluctuation interference, in particular, harmonic interference, in the radio channel significantly reduces the noise immunity of receiving discrete information. The energy loss in this case, depending on the interference intensity, can range from fractions of dB to 10 db or more. Therefore, interference suppression is an important task for such radio systems. The aim of the work is to synthesize and analyze an algorithm for optimal nonlinear filtering of MPSK signals against a background of harmonic interference with a random initial phase.Methods. The provisions of the theory of optimal nonlinear signal filtering and methods of statistical radio engineering are used.Results. The synthesis and analysis of the algorithm of optimal nonlinear filtering of MPSK signals against the background of harmonic interference with a random initial phase are carried out. The synthesized receiver contains a discrete symbol evaluation unit, two phase-locked frequency circuits of reference generators that form evaluation copies of the signal and interference, and cross-links between them. Analytical expressions are obtained that allow calculating the dependences of the bit error probability on the signal-to-noise ratio and the interference intensity µ. It is established that uncompensated fluctuations of the initial phase of the useful signal have a greater effect on the receiver noise immunity than similar fluctuations of the phase of harmonic interference, especially with low positional signals.Conclusions. Comparison of the obtained results with the results obtained in the case when there are no harmonic interference compensation circuits shows that the use of the obtained phase filtering algorithms allows for almost complete suppression of harmonic interference. Thus, if µ = 0.5 and the probability of error is 10−2, the energy gain at M = 2 is about 2.5 dB, at M = 4 – about 6 dB, at M = 8 and M = 16 – at least 10 dB.

scholarly journals NCREASING IMMUNITY OF DECAMETER RADIO CHANNEL TRANSMISSIONS UNDER UNINTENDED INTERFERENCE

T-Comm ◽  
2021 ◽  
Vol 15 (6) ◽  
pp. 4-9
Author(s):  
Sergey V. Dvornikov ◽  
◽  
Evgeniy V. Markov ◽  
Adjan A. Manoshi ◽  
◽  
...  
Keyword(s):  
Fading Channels ◽  
Rayleigh Fading ◽  
Noise Immunity ◽  
Radio Channel ◽  
Radio Waves ◽  
Radio Communication ◽  
Radio Channels ◽  
Shift Keying ◽  
Decameter Radio ◽  
Significant Length

The transmission of messages is a complex process, which is largely determined by the properties of the radio channel used. Decameter radio channels are the most difficult for organizing communication, since the ionospheric propagation of radio waves is associated with their significant attenuation, due to the significant length of the paths, as well as the presence of Rayleigh fading in the channel. However, the possibility of transmitting information over long distances without serious resource costs stimulates further research to improve the reliability of decameter radio communication. In this paper, we investigate the possibility of increasing the noise immunity of frequency-shift keying transmissions of decameter radio channels in conditions of unintentional interference due to the use of broadband signals. An analytical expression of the dependence of the probability of a bit error on the level of the ratio of the peak signal power to the peak interference power is considered; a graph of this dependence is presented. It is shown that the plot is consistent with the overall noise immunity estimate for Rayleigh fading channels using double FSK signals. The rationality of methods for obtaining the required reception quality in decameter radio channels is analyzed. It is shown that the most rational direction for increasing the noise immunity of FM-2 transmissions in decameter radio channels with Rayleigh fading in conditions of unintended interference is the use of broadband signals. In this case, for expansion, it is advisable to choose a value kf = 7, which makes it possible to increase the noise immunity by 9 dB. The conclusions are illustrated by graphs.

scholarly journals Noise immunity of receiving signals with amplitude and phase-shift keying in the presence of phase-shift keying interference

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
G.V. Kulikov ◽  
◽  
Khang Dang ◽  
Keyword(s):  
Phase Shift ◽  
Noise Immunity ◽  
Transmission Rate ◽  
Radio Channel ◽  
Signal Spectrum ◽  
Digital Television ◽  
Phase Shift Keying ◽  
Video Information ◽  
Useful Signal ◽  
Shift Keying

The development of television technologies and the need to transmit high-quality video information requires that modern digital television and broadcasting systems can transmit large amounts of information. The use of signals with multi-position amplitude and phase-shift keying 16-APSK and 32-APSK in DVB-S2 generation satellite television systems made it possible to transmit 30% more data in the same frequency bands compared to the previous DVB-S standard. The latest DVB-S2X digital satellite TV standard is an extension of the DVB-S2 standard and supports modulations of 64,128,256-APSK. It is known that increasing the positionality of signals reduces the noise immunity of their reception and the system as a whole. In addition, the presence of non-fluctuation interference in the radio channel that falls into the frequency band of the useful signal has a strong influence on noise immunity. The article uses statistical radio engineering methods to calculate the probability of a bit error when receiving M-APSK signals against the background of phase-shift keying interference at different parameters of the latter. It is shown that of phase-shift keying interference of even low intensity (µ < 0.3) falling into the main lobe of the signal spectrum significantly reduces the noise immunity of receiving 16-APSK and 32-APSK signals. High-intensity interference (µ ≥ 0.5) practically destroys reception. The influence of phase-shift keying interference decreases with an increase in its detuning relative to the carrier frequency of the useful signal and an increase in the relative transmission rate of the interference. A comparison of the reception quality when using M-PSK, M-QAM and M-APSK signals is carried out and it is shown that the noise immunity of receiving M-QAM and M-APSK against the background of phase-shift keying interference is approximately the same. M-PSK signals are significantly inferior to them in terms of reception noise immunity.

scholarly journals Modeling multi-beam radio channel

Telecom IT ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 59-78
Author(s):  
G. Fokin
Keyword(s):  
Noise Immunity ◽  
Phase Distribution ◽  
Radio Channel ◽  
Amplitude Distribution ◽  
Access Networks ◽  
Doppler Spectrum ◽  
Selective Fading ◽  
Time Frequency ◽  
Frequency Selective Fading ◽  
Radio Access

In this work, a simulation model of a radio channel with fading is implemented for use in research of the multipath channel, as well as for assessing the noise immunity of transmission, recep-tion and processing systems in modern and future mobile communication and radio access networks. Formalization of mathematical models of a radio channel with fading, including the Rayleigh amplitude distribution, uniform phase distribution and a given Doppler spectrum, made it possible to visualize the time-frequency and probabilistic characteristics of a radio channel with fading. The implementation of the procedures for delaying and attenuating copies of signals in a multipath radio channel made it pos-sible to reproduce scenarios of flat and frequency selective fading, which are widely used in practice in assessing the noise immunity of signals with given frequency and time characteristics.

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