Kharkiv National University of Radio Engineering and Electronics,
14, Lenin Ave, Kharkiv, 61166, Ukraine
Wave Scattering on a Cone Surface with the Impedance-Type Boundary Conditions
1Tampere University of Technology, Signal Processing Laboratory,
P. O. Box 553, FIN-33101, Tampere, Finland
2National Aerospace University, Chkalova Str. 17, 61070, Kharkiv, Ukraine
New Noise Immunity Coding Technique with Application of Triple Correlation and Bispectrum
This paper presents a new noise immunity coding technique based on the properties of triple correlation and bispectrum widely used in digital signal and image processing. Encoding and decoding algorithms are described and tested for digital radio telecommunication system with binary frequency shift keying. Probability of errorless decoding has been investigated by computer simulation of transmission and reception of a binary-coded test message in telecommunication system with radio channel disturbed by both the additive white Gaussian noise (AWGN) and mixture of AWGN and impulsive noise. Computer simulation results obtained for varying signal-to-noise ratios smaller than unity at the demodulator input demonstrate considerable improvement of noise immunity of the technique proposed in comparison to the conventional redundant linear block coding technique.
Strukture of the a Priory Probability of Error of the First-Genus Recognition
Reading a Pulsed, Fluctuating-Amplitude Radio Signal in Non-Gaussian Noise at Non-Coherent Reception
Algorithms are suggested for synthesizing detectors capable of reading pulsed signals through the non-Gaussian noise under non-coherent reception. Using the moment and cumulant description of a random variable, the decision rules are built to be optimum according to the criterion of lowest upper bounds of the error probability. The synthesizing detectors have been analyzed, the quality of the detectors based on the non-Gaussian noise consideration has been estimated.
Use of an Adaptive Neuron Network in the Voice Authentication System
Chernivtsi National University, 2 Kotsiubynsky Str.,
58012 Chernivtsi, Ukraine
Optoelectronic Properties of Tin-Doped Zinc Telluride
Algorithm of Synthesis of Matching and Filtering Devices of Multi-Level Amplitude-Phase Manipulators Based on the Use of a Resistance Matrix
Donetsk National University,
24, Universitetskaya Str., Donetsk, 83055, Ukraine
High-Efficiency Microwave BJT Power Amplifier
The analysis of the high-performance microwave power amplifier has been carried out. The way of the partial power passage of the input signal on the output has been presented in power amplifier. The described way of the efficiency increase is the especially effective for the devices working with the low power amplification. In these devices the input signal power is of the same order as output one. The amplifier operation on the transistor ÊÒ911 has been modeled. The total efficiency of the amplifier was 87.5%. The collector current in the significant part of the period was negative. This leaded to the decrease of the average dissipated power by transistor and the efficiency increase in parallel with the remaining positive voltage of the collector-emitter.
A. Usikov Institute of Radio Physics and Electronics,
National Academy of Sciences of Ukraine
12, Academician Proskura Str., Kharkiv 61085, Ukraine
Mechanical Frequency Tuning in Clynotron Oscillators
The paper is devoted to a discussion of various methods of the mechanical frequency tuning in the clynotron-type oscillators operating in millimeter and submillimeter wave ranges. Several clynotron modifications with the mechanical frequency tuning are considered in terms of their design and characteristics.