Interference Immunity of Reception of Phase-Shift Keyed Signals in Conditions of Powerful Structural Interference

2008 ◽  
Vol 67 (12) ◽  
pp. 1107-1117
Author(s):  
V. V. Bazykin ◽  
A. P. Bogomolov ◽  
Yu. M. Kutsan
Keyword(s):  
Phase Shift ◽  
Interference Immunity

scholarly journals Potential interference immunity of coherent reception of quadruple phase-manipulated radio signal in the presence of coherent harmonic interference

2021 ◽  
pp. 45-54
Author(s):  
Vitalii Zvonarev ◽  
Aleksandr Popov
Keyword(s):  
Phase Shift ◽  
Radio Signal ◽  
Radio Channel ◽  
Energy Parameter ◽  
Interference Immunity ◽  
Probability Densities ◽  
Energy Ratios ◽  
Noise Ratio ◽  
The Given ◽  
Interference Phase

Introduction: The known methods for calculating the interference immunity of radio signal reception in the presence of, for example, harmonic interference, often lead to significantly different numerical values. Each calculation technique of this type has its own algorithm for the resulting formula output, and these conclusions are based on a different level of “engineering rigor”. Purpose: To develop, оn the basis of linear transformation of coordinates, a correct method for calculating the error probability in the correlating reception of a four-fold phase-manipulated radio signal in the presence of coherent harmonic interference. Methods: Four-dimensional probability density of a vector of output voltages of the demodulator correlators in a four-fold integral was represented by a product of one-dimensional probability densities in the space of eigenvectors of the covariance matrix, in which two probability densities are Dirac delta functions. The quadruple integral is brought to double, with new integration limits defined from the plane equations bounding the integration region in this space. Results: Formulas were derived for accurate calculation of average probabilities of symbol and bit errors in coherent reception of a four-fold phase-manipulated radio signal in the presence of coherent harmonic interference. The derived exact formulas were used to plot the dependencies of the average probabilities of symbol and bit errors on the signal-to-noise ratio for the given interference-to-noise ratio and the given interference phase shift relative to the signal phase. It has been studied how the energy ratios of the signal and interference, as well as the interference phase shift, affect the probabilities of symbol and bit errors. It was found that the influence of a non-energy parameter equivalently leads to a change in the energy ratios. Practical  relevance: The results of the research can be used in assessing the communication efficiency under interference. The developed technique will allow you to accurately determine the energy characteristics of a radio channel providing the required quality for the reception of transmitted messages in presence of harmonic interference.

scholarly journals Application of Broadband Signals to Increase Interference Immunity in Channels with Inter-Symbol Interference

2021 ◽  
Vol 2096 (1) ◽  
pp. 012046
Author(s):  
V K Fedorov ◽  
E G Balenko ◽  
S V Dvornikov ◽  
O S Lauta
Keyword(s):  
Phase Shift ◽  
Fading Channels ◽  
Noise Immunity ◽  
Phase Shift Keying ◽  
Practical Application ◽  
Interference Immunity ◽  
Shift Keying ◽  
Rice Fading ◽  
Inter Symbol Interference

Abstract Proposals for improving the noise immunity of receiving phase-shift keying signals in the conditions of inter-symbol interference caused by fading in the channel are presented. The use of Barker sequences for the expansion of modulating information pulses has been substantiated. The results of evaluating the noise immunity of Rice fading channels at various ratios of the effective voltages of the regular and diffuse signal components are presented. Proposals for the practical application of the results obtained are formulated.

Noise immunity and interference security of control radio links operating with phase-shift keyed broadband signals

2021 ◽  
Author(s):  
N.M. Ashimov ◽  
A.S. Vasin ◽  
A.N. Birukov ◽  
P.G. Kuzmishchev
Keyword(s):  
Phase Shift ◽  
Noise Immunity ◽  
Narrow Band ◽  
Practical Significance ◽  
Signal Spectrum ◽  
Interference Immunity ◽  
Wideband Signals ◽  
Approach Method ◽  
Technical Systems ◽  
Theoretical Issues

This article observes an information concerning phase-keyed binary signals, the wideband of which is achieved with simply increasing the bit size of the code, as well as wideband composite phase-keyed signals, when each symbol is represented with a multi-bit binary forward or inverse sequence. The purpose of the article is to present criteria and methods for evaluating interference immunity and interference immunity of control radio links which forms a special class of radio technical systems (RTS) and which require a different methodology of analysis of these issues than is accepted in radio. Using the normal approach method, the interference immunity and interference immunity of control radio links operating with narrowband and wideband signals are compared. It is shown that with increasing code bit size which is accompanied by signal spectrum expansion, RLS noise immunity coefficient increases, asymptotically approaching its maximum possible value. Transition from narrow-band the phase-manipulated signals to wideband composite signals is accompanied by decreasing of coefficient of noise stability by / 2 times. The article deals with mainly theoretical issues. The practical significance of the article is bringing real indicators of noise immunity as close as possible to the maximum possible.

Object Wave Determination by Single-Sideband Methods

1973 ◽  
Vol 31 ◽  
pp. 266-267
Author(s):  
Kenneth H. Downing ◽  
Benjamin M. Siegel
Keyword(s):  
Phase Shift ◽  
Carbon Films ◽  
Object Wave ◽  
Electron Wave ◽  
Phase Object ◽  
Heavy Atoms ◽  
Single Sideband ◽  
Thin Carbon ◽  
Additional Phase Shift ◽  
Additional Phase

Under the “weak phase object” approximation, the component of the electron wave scattered by an object is phase shifted by π/2 with respect to the unscattered component. This phase shift has been confirmed for thin carbon films by many experiments dealing with image contrast and the contrast transfer theory. There is also an additional phase shift which is a function of the atomic number of the scattering atom. This shift is negligible for light atoms such as carbon, but becomes significant for heavy atoms as used for stains for biological specimens. The light elements are imaged as phase objects, while those atoms scattering with a larger phase shift may be imaged as amplitude objects. There is a great deal of interest in determining the complete object wave, i.e., both the phase and amplitude components of the electron wave leaving the object.

A Many-Beam Technique for Enhanced Resolution of Partial Dislocations

1972 ◽  
Vol 30 ◽  
pp. 646-647
Author(s):  
J. M. Oblak ◽  
B. H. Kear
Keyword(s):  
Phase Shift ◽  
Field Method ◽  
Dark Field ◽  
Bright Field ◽  
Field Technique ◽  
Weak Beam ◽  
Partial Dislocations ◽  
Enhanced Resolution ◽  
Nickel Base ◽  
Beam Technique

The “weak-beam” and systematic many-beam techniques are the currently available methods for resolution of closely spaced dislocations or other inhomogeneities imaged through strain contrast. The former is a dark field technique and image intensities are usually very weak. The latter is a bright field technique, but generally use of a high voltage instrument is required. In what follows a bright field method for obtaining enhanced resolution of partial dislocations at 100 KV accelerating potential will be described.A brief discussion of an application will first be given. A study of intermediate temperature creep processes in commercial nickel-base alloys strengthened by the Ll2 Ni3 Al γ precipitate has suggested that partial dislocations such as those labelled 1 and 2 in Fig. 1(a) are in reality composed of two closely spaced a/6 <112> Shockley partials. Stacking fault contrast, when present, tends to obscure resolution of the partials; thus, conditions for resolution must be chosen such that the phase shift at the fault is 0 or a multiple of 2π.

Observation of surface morphology by reflection electron holography

1989 ◽  
Vol 47 ◽  
pp. 536-537
Author(s):  
N. Osakabe ◽  
J. Endo ◽  
T. Matsuda ◽  
A. Tonomura
Keyword(s):  
Phase Shift ◽  
Surface Morphology ◽  
High Sensitivity ◽  
High Energy ◽  
Path Difference ◽  
Transmission Mode ◽  
Electron Holography ◽  
Dynamical Process ◽  
High Vertical Resolution ◽  
Amplification Technique

Progress in microscopy such as STM and TEM-TED has revealed surface structures in atomic dimension. REM has been used for the observation of surface dynamical process and surface morphology. Recently developed reflection electron holography, which employes REM optics to measure the phase shift of reflected electron, has been proved to be effective for the observation of surface morphology in high vertical resolution ≃ 0.01 Å.The key to the high sensitivity of the method is best shown by comparing the phase shift generation by surface topography with that in transmission mode. Difference in refractive index between vacuum and material Vo/2E≃10-4 owes the phase shift in transmission mode as shownn Fig. 1( a). While geometrical path difference is created in reflection mode( Fig. 1(b) ), which is measured interferometrically using high energy electron beam of wavelength ≃0.01 Å. Together with the phase amplification technique , the vertivcal resolution is expected to be ≤0.01 Å in an ideal case.

Inelastic mean free path and phase-shift determinations in NiO, using EXELFS

1993 ◽  
Vol 3 (7) ◽  
pp. 1649-1659
Author(s):  
Mohammad A. Tafreshi ◽  
Stefan Csillag ◽  
Zou Wei Yuan ◽  
Christian Bohm ◽  
Elisabeth Lefèvre ◽  
...  
Keyword(s):  
Phase Shift ◽  
Free Path ◽  
Mean Free Path ◽  
Inelastic Mean Free Path
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