Mathematical description and formalization types of distortion in a digital communication channel with OFDM-signals
Journal Title: Вісник НТУУ КПІ. Серія Радіотехніка, Радіоапаратобудування - Year 2016, Vol 0, Issue 66
Abstract
Introduction. OFDM technology is widely used in digital television, broadcasting and communication systems. The biggest OFDM advantage is its high spectral efficiency. But the high spectral efficiency needs high-quality synchronization. That is why it is important to analyze received signals distortions appearing because of timing inaccuracy in order to create their compensation algorithms.Mathematical analysis of distortions as a result of uncoordinated timing parameters. Using Fourier transformations properties, the expression for calculation of displacement effect and phase shift of carrier frequency, displacement of timing frequency on the informational signal in the frequency region were acquired. With the help of computer, acquired expressions were simulated and the influence of different uncoordinations on the modulation constellations for the standards of digital video systems ISDB-T were shown.Conclusion. As is seen from the modelling results, inessential inaccuracies at the synchronization cause quite critical distortions that as a result significantly worsen bit error rate. The acquired results let us estimate validity of operation of distortion compensation algorithms as a result of inaccurate synchronization in the process of system development or its verification.
Authors and Affiliations
V. Kotliarov, O. Myronchuk
Electromagnetic waves interaction with a multi-layered spherical lens
Solution of interaction electromagnetic radiation problem with lamellar spherical lens is obtained. The elaborated method determinates dependence of absorbing, scattering and extinction versus slabs characteristics.
Algorithm of the tuning by the wideband transforms of the frequency
Methods of the wideband search and transformation of the frequency continuous and pulse-modulated signals are described. It suggested algorithms tuning by circuits of the transforms, which allows reaching of the simple...
Comparative characteristics of the bases of wavelets to represent the speech signals
Wavelets allow us to delineate both a low frequency signal characteristics, and high-frequency components. This property is a significant advantage in problems of speech signal processing in comparison with the windowed...
Authentification of person on the dinamically entered signature at the use of normal transformation
The algorithm of authentification of person on the dinamically entered signature, built on the base of normal transformation is offered
Radio-technical characteristics of plasma and metal antennas mounted on aircrafts and spacecrafts
RT characteristics of plasma and metal antennas (VSWR, RP, gain, efficiency) installed on aircrafts and spacecrafts and their fragments in the software environment EMSS FEKO are investigated. It became possible to carry...