Items of № 7, 2010

The Electrosvyaz Magazine is one of the leading science & technical magazines in Russia.

Sound-broadcasting and TV sound. Basic regulatory standards

BUTENKO V.V., KHAZANOVA M.A.

Key words: Sound broadcasting, television sound, sound signals, sound broadcasting channels, key parameters.


 

Analyzing DVB-T system’s interference immunity in a multipath fading channel as a model

KRASNOSSELSKY I.N., KANEV S.A.

The interference immunity of digital broadcasting terrestrial DVB-T signal has been researched. Analyzed signal was received after Gaussian, Raleigh and Rice channel models. The article includes measurements of a bit error ratio at the input and output of Viterbi decoder. Based on this measurement are different system variants comparison presented. Compared variants have different modulation, code rate and reflection responsivity. It has been shown that system combinations of 64QAM modulation and high code rate in DVB-T don’t have considerable reserve of interference immunity.

Key words: Digital terrestrial television broadcasting, DVB-T system, multipath propagation, bit error ratio, carrier/noise ratio.


 

Assessing nonlinear distortion in a digital TV transmitter’s power amplification system

SHAKHGILDYAN V.V., KARYAKIN V.L., TOLMACHEV V.B.

The methodology estimates Distortion channel power amplifier of digital television transmitter using a visual modeling environment. The method presented in the form of algorithms for the preparation of the study, the study of spectral and energy characteristics research intermodulation distortion, the algorithm for finding the spectral mask, recommendations to minimize the distortion.


Parametric optimization of ASIC library items in HDTV components designing

PERMINOV V.N., KOKIN S.A., MAKAROV S.V., VESELOV A.E.

The paper describes a modified Levenberg-Marquardt algorithm used for parametric optimization of specialized ASIC libraries used in HDTV components design.

Key words: Levenberg-Marquardt, LMA, parametric optimization, ASIC library, HDTV components.


Increasing interference immunity at data transmission through an OFGM channel hindered by noise complicated conditions

ANDRIANOV M.N., BUMAGIN A.V., GONDAR A.V., PRUDNIKOV A.A., STESHENKO V.B.


Amplitude controllers for powerful impulse signals

TITOV A.A., PUSHKAREV V.P.

Signal adjustment, modulation and limiting controllers are used in lots of radio systems. The drawback of the known circuit designs of such units is a small level of controlled impulses. To create amplitude controllers for powerful impulses, the effect of clipping powerful impulse signals by closed bipolar transistor was suggested. Based on the noted effect, there were developed unidirectional impulse amplifiers protectors to prevent them from current overload, as well as signal adjustment, modulation and limiting controllers for powerful impulse signals. The description of schematic circuits and functional principles of these units, and their specifications are given.

Key words: impulse signal, controllers, signal adjustment, signal modulation, signal limiting.


Turbo-codes class with low decoding complexity

NAZAROV L.E., GOLOVKIN I.V.

The turbo-codes based on serially concatenation of short block codes and simple 2-state recursive convolutional code are investigated. For that turbo-codes the efficient iterative decoding algorithm with low-complexity in comparison to iterative decoding algorithms for classical turbo-codes based on parallel concatenation of two 16-state recursive convolutional codes is proposed.

Key words: Turbo-codes, iterative decoding, Fast Hadamard Transformation.


Evaluation of analog-digital conversion’s effect on garbling at audio data compression coding

OBOLONIN I.A., RYGOVSKAYA N.A.

The Compression of the digital audiodata in psychoacoustic models of standards МРЕG is inevitably accompanied by distortions of quality of stereophonic sounding (fixed experts), such as spatial impression, a sounding transparency, naturalness and riches of timbres of tools and voices, perception of acoustic atmosphere of a primary premise. It is connected with lacks of the model. However on quality of sounding essential influence renders also actually analogue-digital transformation of an initial audiosignal. In work the most essential impact on specified above distortion is considered three aspects of the primary analogue-digital transformation, making. It is specific character of a spectrum of errors of quantization, a filtration of signals at analogue-digital and digit-analogue transformations and protection DAC against the overloads, causing nonlinear distortions of an audiosignal.

 

 

 

 

 

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