A Generalized Spatial Modulation System Using Massive MIMO Space Time Coding Antenna Grouping

Massive multiple input multiple output (MIMO), also known as a very large-scale MIMO, is an emerging technology in wireless communications that increases capacity compared to MIMO systems. The massive MIMO communication technique is currently forming a major part of ongoing research. The main issue for massive MIMO improvements depends on the number of transmitting antennas to increase the data rate and minimize bit error rate (BER). To enhance the data rate and BER, new coding and modulation techniques are required. In this paper, a generalized spatial modulation (GSM) with antenna grouping space time coding technique (STC) is proposed. The proposed GSM-STC technique is based on space time coding of two successive GSM-modulated data symbols on two subgroups of antennas to improve data rate and to minimize BER. Moreover, the proposed GSM-STC system can offer spatial diversity gains and can also increase the reliability of the wireless channel by providing replicas of the received signal. The simulation results show that GSM-STC achieves better performance compared to conventional GSM techniques in terms of data rate and BER, leading to good potential for massive MIMO by using subgroups of antennas.     

Synthesis of a <Superscript>188</Superscript>Re–DTPMP complex using carrier-free <Superscript>188</Superscript>Re and study of its stability

Labeling of diethylenetriamine-N,N,N′,N″,N″-pentakis(methylenephosphonic) acid (DTPMP) with rhenium-188 using stannous chloride as a reducing agent has been investigated. Dependence of the yield of the ¹⁸⁸Re–DTPMP complex on the concentration of the reducing agent, pH, reaction time, temperature, ascorbic acid and amount of carrier added has been studied. Under optimum conditions, the labeling yield of ¹⁸⁸Re–DTPMP complex is 95% for the carrier-free ¹⁸⁸Re but with the carrier-added ¹⁸⁸Re the labeling yield is more than 97%. Furthermore, the stability of the ¹⁸⁸Re–DTPMP complex against pH change and dilution with saline has been also studied. It is found that the addition of carrier stabilizes the ¹⁸⁸Re–DTPMP complex against pH change and dilution.     

Quantum treatment of the time-dependent coupled oscillators under the action of a random force

In this communication we introduce the problem of time-dependent frequency converter under the action of external random force. We have assumed that the coupling parameter and the phase pump are explicitly time dependent. Using the equations of motion in the Heisenberg picture the dynamical operators are obtained, however, under a certain integrability condition. When the system is initially prepared in the even coherent states the squeezing phenomenon is discussed. The correlation function is also considered and it has been shown that the nonclassical properties are apparent and sensitive to any variation in the integrability parameter. Furthermore, the wave function in Schrödinger picture is calculated and used it to derive the wave function in the coherent states. The accurate definition of the creation and annihilation operators are also introduced and employed to diagonalize the Hamiltonian system.     

Data detection of MPSK in the presence of rapidly changing carrierphase

We present a novel method for data detection of M-ary phase shift keying (MPSK) in the presence of unknown carrier phase and additive white Gaussian noise. Here, the unknown carrier phase is rapidly changing and random. That is, the unknown phase changes from symbol to symbol in a nondeterministic manner. The rate of phase change is such that phase change over two symbol intervals is negligible, but it is not necessarily negligible over a longer interval. Our proposed system outperforms traditional differential phase shift keying (DPSK) by 1.5 dB at error probabilities of 10^-3 and 10^-4. We also compare the performance of our scheme with that of multiple symbol differential detection (MSDD). Except under very slow phase change conditions, our scheme outperforms MSDD. Our decoder is well suited to mobile communication systems. Here, receivers usually move with different speeds at different times     

Vertical vibration of a circular stamp on an elastic-porous half-space with saturation fluid

A specific problem concerning the vertical vibrating response of a composite layer (elastic-porous and saturation fluid) under rigid circular stamp is studied. The motion of the medium is governed byBiot’s dynamic potential equations and the problem is solved by the method of Fourier-Bessel transformation. Formulae are obtained for the vertical displacement of the rigid phase. Graphs are presented for the amplitude of vibration.     

A dual-path sequence of first-order reactions the protiodeacylation of acetylpropionylmesitylene

An example of a sequence of competing first-order reactions, leading to a common product, has been found for the sulfodeacylation of acetylpropionylmesitylene. The basic reaction scheme is Scheme l and a kinetic analysis of the component rate constants allows an estimate to be made of the concentrations of the reactant and products as a function of time. In the present system the total concentration of the intermediates B, C, and D never exceeds 0.26% at 25°C, and therefore the kinetics, which were followed spectrophotometrically, were essentially of the conversion of substrate A to the final product E. The kinetics of protiodeacylation have been measured, over a range of temperatures, of propionyl-, dipropionyl-, and acetylpropionylmesitylenes in 89.8% (w/w) sulfuric acid.     

Discontinuous polyacrylamide gel-agarose gel immunoelectrophoresis for analysis of plasma lipoproteins

A modification of crossed immunoelectrophoresis for the analysis of plasma lipoproteins is described and is called polyacrylamide gel-crossed immunoelectrophoresis. The incorporation of albumin in the first-dimensional gel facilitates the transfer of the larger lipoproteins containing apolipoprotein B from the first-dimensional gel to the second dimension. Furthermore, under this condition the quantitation of total apolipoprotein B by polyacrylamide gel-crossed immunoelectrophoresis is in good agreement with the results obtained by rocket immunoelectrophoresis or nephelometry. The correlation between polyacrylamide gel-crossed immunoelectrophoresis and rocket immunoelectrophoresis is good for total apolipoprotein B (p greater than 0.001) and apolipoprotein A-I (p greater than 0.001). Polyacrylamide gel-crossed immunoelectrophoresis also offers interesting aspects to study the plasma lipoprotein classes and subclasses in different cases: normal plasma, current and complex dyslipoproteinemias in the presence or absence of lipoprotein small a. In a case of dyslipoproteinemia of Fredrickson's Type V polyacrylamide gel-crossed immunoelectrophoresis demonstrates the presence of a small-sized Lp (a) major peak in the low density lipoprotein (LDL) zone and of a large-sized Lp (a) minor peak in the very low density lipoprotein (VLDL) zone.     

A numerical model for electromagnetic scattering from sea ice

A numerical model for scattering from sea ice based on the finite difference time domain (FDTD) technique is presented. The sea ice medium is modeled as consisting of randomly located spherical brine scatterers with a specified fractional volume, and the medium is modeled both with and without a randomly rough boundary to study the relative effects of volume and surface scattering. A Monte Carlo simulation is used to obtain numerical results for incoherent υυ backscattered normalized radar cross sections (RCSs) in the frequency range from 3 to 9 GHz and for incidence angles from 10° to 50° from normal incidence. The computational intensity of the study necessitates an effective permittivity approach to modeling brine pocket effects and a nonuniform grid for small scale surface roughness. However, comparisons with analytical models show that these approximations should introduce errors no larger than approximately 3 dB. Incoherent υυ cross sections backscattered from sea ice models with a smooth surface show only a small dependence on incidence angle, while results for sea ice models with slightly rough surfaces are found to be dominated by surface scattering at incidence angles less than 30° and by scattering from brine pockets at angles greater than 30°. As the surface roughness increases, surface scattering tends to dominate at all incidence angles. Initial comparisons with measurements taken with artificially grown sea ice are made, and even the simplified sea ice model used in the FDTD simulation is found to provide reasonable agreement with measured data trends. The numerical model developed ran be useful in interpreting measurements when parameters such as surface roughness and scatterer distributions lie outside ranges where analytical models are valid     

A new nano-structured Ni(II) Schiff base complex: synthesis,characterization, optical band gaps,and biological activity

New Ni(II) Schiff base complexes [{Ni(L)(H₂O)Cl} where HL = 2-((pyridin-3-ylmethylene)amino)phenol] have been synthesized using the reflux and sonochemical methods. The nickel oxide NiO nanopowder was obtained from the metal complexes after calcination at 650 °C for 2 h. The Schiff base complexes and NiO powders were characterized in detail. The HL and its metal complexes were depicted high activity towards microorganism and breast carcinoma cells. The inhibitory activity against breast carcinoma (MCF-7) were detected with IC₅₀ = 5.5, 12.5 and 9.6 for HL, complex (1) and complex (2), respectively. The optical band gap energy was 3.6, 3.0 and 2.37 eV for Ni complexes (1), (2) and NiO, respectively. The microstructure of the formed NiO powders appeared as cubic-like structure. Furthermore, magnetic properties of NiO sample were identified and paramagnetic property was found at a room temperature. The saturation magnetization and coercive force for the NiO sample were 0.47 emu/g and 42.68 Oe, respectively.     

Easily attainable new approach to mass yield ferrocenyl Schiff base and different metal complexes of ferrocenyl Schiff base through convenient ultrasonication‐solvothermal method

A new alternative approach with crucial mass yield and high reaction rates is proposed for the synthesis of ferrocenyl Schiff bases using an ultrasonication‐solvothermal method. Equimolar condensation of ferrocenecarboxaldehyde and 2‐aminophenol interact with each other, giving 1‐(1‐[2‐hydroxyphenyl‐2‐imino]methyl)‐ferrocene (FcOH). Furthermore, this ligand forms 1:1 complexes with cobalt(II), nickel(II), copper(II), and palladium(II) ions. From the different spectral data, it is found that metal ions coordinate with ligands through the azomethine group and the deprotonated oxygen of the phenol groups. Moreover, FcOH and their complexes were characterized by elemental analysis, Fourier transform infrared, ¹H nuclear magnetic resonance, and UV‐visible spectrophotometry. The spectral data of FcOH and its metal complexes were discussed in connection with the structural changes due to complexation. Meanwhile, the information about geometric structures can be concluded from the electronic spectra and the magnetic moments. Plainly, electron spin resonance spectra of the Cu(II) complex revealed d_x2?y2 as a ground state, suggesting a square planar geometry around the Cu(II) center. The direct optical band gap energy E_g values of cobalt, nickel, copper, and palladium complexes of FcOH are found to be 3.7, 3.9, 4.6, and 3.65 eV, respectively. 1‐(1‐[2‐Hydroxyphenyl‐2‐imino]methyl)‐ferrocene and its metal complexes were screened for antibacterial activity. The results depict that the metal complexes were found to be more strongly antibacterial than the guardian Schiff base ligand (FcOH) against one or more bacterial species. The minimum inhibitory concentrations of antimicrobial properties of the purified compound were determined using the broth microdilution method.