Abstract It is considered a technique of mutual application of multi-antenna MIMO systems and multiplexing with orthogonal frequency division of OFDM channels for current-technology systems of wireless communication of special application. There are defined areas of prior application of time and frequency variant of diverse signals transmission according Alamouti principle for wireless channels with

Abstract The paper proposes a new numerical measure for filtering quality assessment of additive white Gaussian noise in digital images based on the analysis of closeness of the difference image to white noise. Such analysis is often conducted visually that leads to undesirable subjectivism. The numerical analysis of difference image using the properties of nonparametric BDS statistic was performed

Abstract A circularly polarized (CP) CPW-fed (CoPlanar Waveguide) with two asymmetric U-shaped strips, patch antenna is described in this paper. The antenna consists of a radiating patch composed of a hexagonal-ring connected with two annular rings on the two corners, which provide wide CP. The CPW-fed antenna was constructed by etching out two L-shaped slots and adding two asymmetric U-shaped strips

Abstract The ruggedness of emerging single adaptive approach that performs well in all types of operating conditions has led to the development of composite adaptive strategy. In this regard, the fusion of particular decisions of single adaptive schemes through suitable fusion rules can provide a better final detection. Particularly, the fusion of cell-averaging (CA), ordered statistics (OS) and trimmed-mean

Abstract Application of multi-frequency radiolocation allows to expand essentially received signals spectrum that increases amount of a target (object) classification identifiers including thermal portraits for radiometric measurements. In this paper it is represented a prototype of measuring radiometric unit allowing to carry out simultaneously contactless radiometric research of liquids in two wavelength

Abstract The digital compensation process for nonlinearly inertial characteristic of the transmit path of dual-band communication system with concurrent data transmission in the presence of unbalance of modulator quadratures has been considered. Analytical relationships enabling us to identify adaptively or change the parameters of dual-band polynomial model of corrector with due regard for the modulator

Abstract Analysis of discrete estimates of bi-periodically correlated random processes (BPCRP)—mathematical models of signals with double stochastic periodicity was performed using least squares (LS) technique. It is shown that LS utilization allows to avoid systematic errors related to leakage effect. Expressions for estimate bias and dispersion were obtained, allowing determination systematic and

Abstract A new statement of the problem on the calculation of kinematic and dynamic characteristics of surface acoustic waves in piezoelectric monocrystals is proposed. A procedure for solving the above problem is also proposed with due regard for the existence of electric field scattering on the crystal surface not covered with electrodes and the vortex component of electric field in the general case

Abstract Spatial correlation is a crucial impairment for practical Multiple Input Multiple Output (MIMO) wireless communication systems. It is important to consider spatial correlation between antennas in actual communication scenario at both sides, i.e. transmit and receive side. Furthermore, we have considered nonorthogonal full rate STBC in MIMO systems equipped with four transmit antennas and four

Abstract This paper describes the development of embedded software for the implementation and testing of the artificial multistable neuron model’s basic behavior with the help of the hardware architecture of programmable logic integrated circuits (FPGA). The real behavior and function of the biological neuron with linearized activation characteristics are investigated and implemented in the programming

Abstract Space-time-frequency (STF) coding can obtain the diversity gain from three dimensions (space, time and frequency) to effectively improve the transmission performance of the multi-input multi-output (MIMO) relay system. In this study, a MIMO one-way two-hop amplify-and-forward (AF) relay communication system is presented by means of triple Khatri–Rao space-time-frequency (KRSTF) coding, which

Abstract The quality of reception of radio signals at the destination is greatly influenced by the type of signaling schemes used and the use of multiple antennas at the output of transmitter and the input of receiver. However, this configuration usually causes InterCarrier Interference (ICI), which leads to distortions. In this paper, the performance of 6×6 multiple antenna beamforming in offset 16

Abstract In this paper, two digitally-controlled ring oscillators (DROs) with similar structure but different constructive cells have been proposed. These proposed DROs include of 5 stages, and each stage contains 10 parallel delay cells. In addition, each stage has fine and coarse parts for adjusting the output frequency. The proposed designs have a wide frequency range and high frequency. The frequency

Abstract In this paper, we present the radiated mode indoor radio coverage performance study of a co-existing dual technology, dual 4×4 Multiple Input Multiple Output (MIMO) antenna platform. The antenna platform is targeted to be used for low power wireless radio Base Station (BS) applications. One of the 4×4 MIMO antenna pairs operates in the 2.5–2.7 GHz licensed Long Term Evolution (LTE) band while

The numerical optimization results of constant thickness septum polarizer’s performances for various operating fractional bandwidths (FBW) are presented in the paper. The polarizer’s structure includes a common input square waveguide, a constant thickness septum with several steps, and two output rectangular waveguides. The polarizer design of 2-, 3-, 4-, and 5-step septums is optimized for different

The exact knowledge of the clutter properties is of great importance for modern radar systems due to the role that they are directly play mainly through the CFAR processor design in the optimization of the detection process. Owing to the central limit theorem, the most used models are of Gaussian distribution that has the feature of simple processing architectures. Actually, these models are expected

This paper describes the algorithm of antenna array (AA) calibration, which estimates and compensates phase lags, caused by non-identical electrical characteristics of array channels. The algorithm does not require the access to the channel signals or the channels disabling. It uses only the array output power measurements under the specific channel phase perturbations. The algorithm accuracy equals

It is considered a problem of automatic speech recognition at basic, phonetic level of speech signal processing. It is researched a problem of noise-immunity increase. For its solution it is proposed a criterion of minimum information divergence of the signals with tuning to a speaker voice and automatic scaling of speech template to thin structure of observed (current) speech frame. An example of

Two methods have been proposed for enhancing the accuracy in determining the coordinates of radio emission sources by using phase systems based on reducing the dynamic and random errors in terms of the curvature of electromagnetic wave phase front during processing the signals at inputs of linear antenna array. The reduction of dynamic errors stipulated by the limited number of terms of the Maclaurin

In this paper it is represented an efficient method for calculation of periodic stationery states of non-linear electronic circuits at time domain. The method is based on application of Kotelnikov-Shannon series for approximation of derivatives of mathematic models of the circuit. Cyclic approximation form with application of Shannon kernel allows to obtain simple matrix relation for the derivatives

The paper considers the problem of determining the eigenfrequencies of biconical cavity making it possible to simplify the eigenfrequency-based design of devices. We used the solving of the excitation problem for biconical cavity using the method of partial intersecting regions in combination with the collocation method. Based on the concept of the search of quasisolution for determining eigenfrequencies

A compact ultra-wideband circular monopole antennas with single, dual, triple and quad-band rejection characteristics are proposed in this paper. The antenna units are designed using RT/DUROID substrate with permittivity 2.2 and all are fed through a coplanar waveguide (CPW). In the proposed antennas splitted concentric rings (SCR) are used to achieve band rejection characteristics. The proposed antennas

In this paper, we consider Mt×M system (Mt > M), where Mt and M are the numbers of antennas at the transmitter and receiver, respectively. We select M out of Mt transmit antennas using two different antenna selection schemes. In scheme 1, we select the subset of M antennas out of total \((\begin{array}{l}{M_{t}} \\{M}\end{array})\) subsets. In the selected subset, the minimum SNR is maximum compared

Synchronization is a complex task in uplink Orthogonal Frequency Division Multiple Access (OFDMA) for Mobile WiMax as each user presents different Carrier Frequency Offsets (CFO). Synchronization begins with the CFO estimation and followed by the compensation of residual CFO present in the received signal. This paper deals with various techniques in time and frequency domains to compensate the effect