Method for efficient representation of the information on the weighting coefficients of a transmitting beamformer in wireless digital communication systems with multielement adaptive antennas

We consider the problem of transmission of channel state information for a transmitting beamformer in digital communication systems with adaptive transmitting and receiving antennas. It is shown that using the unitary property of the weighting matrices of the transmitting beamformer, we can significantly reduce the amount of transmitted information with the help of the well-known Givens decomposition. We propose a method for determining the optimal bit allocation for quantization of the complex weighting coefficients of the transmitting beamformer. Results of mathematical simulation of a wireless digital communication system with multielement adaptive antenna arrays are shown for a multipath Rayleigh channel. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 51, No. 9, pp. 814–823, September 2008.     

Synthesis,characterization, crystal structure and catalytic activity of amido azo palladium(II) complex

Transition Metal Chemistry - The newly designed tridentate ligand, 2-((2-aminophenyl)diazenyl)-N-benzylaniline, 1 has been synthesized by the reaction between 2,2′-diaminoazobenzene and...     

Regioselective N(2)-H-functionalization of thiosemicarbazones of aromatic and heteroaromatic aldehydes with acrylonitrile

Regioselective N(2)-H-cyanoethylation of thiosemicarbazones of aromatic and heteroaromatic aldehydes with acrylonitrile proceeds under mild conditions (14% KOH, acetone/H₂O, 35?°C, 6–21?h) to afford 1-(2-сyanoethyl)-2-[(E)-aryl(heteroaryl)methylidene]-1-hydrazinecarbothioamides in up to 74% yields. The synthesized thioamides are promising precursors of novel families of functionalized thiosemicarbazones as exemplified by hydrolysis of their cyano group to the corresponding amido function (46.5–60% yields).     

Mössbauer studies of the surface and bulk properties of substituted iron-garnet films in the vicinity of the Curie point

The magnetic properties of the surface layer and bulk of iron-garnet films of composition Y_2.6Sm_0.4Fe_3.7Ga_1.3O₁₂, grown by liquid-phase epitaxy on substrates of a gadolinium-gallium garnet single crystal, are investigated. The method of simultaneous gamma-ray, x-ray, and electron Mössbauer spectroscopy is used for the investigations. It is found that the temperature T _c(L) of the transition to the paramagnetic state of a thin layer localized at a depth L below the surface within ～300 nm decreases smoothly with decreasing distance from the surface. The causes of the difference between the temperature of the transition to the paramagnetic state in the surface layer and that bulk of the film are: 1) variation of the degree of substitution of gallium for iron in the surface layer; 2) weakening of exchange interactions at the surface of the sample.     

Testing of autohesion of hard polyvinyl chloride foils by delamination in acetone and hole theory of autohesion

To test the autohesion of hard PVC foils, delamination in acetone was used. The following points are discussed briefly: the diffusion of acetone in PVC, the cause of delamination, disadvantages of the method and the information which can be derived from swelling in acetone. For one type of PVC foil, the results were expressed in terms of a regression equation. The course described by the regression equation does not agree with any existing autohesion theories. Therefore, the hole theory of autohesion was formulated, in good agreement with the experimental values.     

The comparing of two methods in Microbiology

In many microbiological assays the presence or absence of microbes by two methods, sayA andB, is examined. In this paper the statistical method is developed giving the estimate of probability of detecting the microbes by the two methods used.