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Adaptive Coded Continuous-Phase Modulations for Frequency-Division Multiuser Systems

100%

Perotti A. , Remlein P. , Benedetto S.

2010

tom Vol. 1, no. 1

50--58

In this paper we study adaptive coded modulations for wireless channels. Nonlinearity due to the radio-frequency power amplifier is considered and continuous-phase modulations (CPM) are adopted in order to make the nonlinearity effects negligible. The structure and properties of CPM are reviewed in a semi-tutorial fashion and coded modulation schemes are proposed. Moreover, frequency-division multiplexing (FDM) multiuser systems employing coded CPM are considered. Modulation-coding schemes achieving increasing spectral efficiencies in a multiuser scenario with tight intercarrier frequency spacing are designed and their performance in terms of spectral efficiency and error rate is assessed.

Temperature Distribution Measuring System

100%

Bazylevych O. , Ivakhiv O. , Velgan R.

tom R. 53, nr 9 bis

583--585

The pyrometer moving along the stove axis can be used for the surface temperature measurement of the circulating cement stove. By the temperature distribution along the rotor stove measuring, all possible temperature values in space and time can be described using a simple two-dimensional random temperature field model. Thus, the measuring signal is redundant, and it is possible to use the known compression techniques in order to reduce the requirements to the measuring information processing rate. The paper presents expressions estimating the parameters of this kind of adaptive system.

Pomiar rozkładu temperatury powierzchni pieca do wypalania cementu zrealizowano za pomocą pirometru poruszającego się wzdłóż osi pieca. Jako dane pomiarowe do modelu matematychnego rozkładu temperatury w czasie i przestrzeni wykorzystano dwuwymiarowe pole losowe temperatury zarejestrowane pirometrem. W związku z faktem, że sygnał pomiarowy zawiera więcej niż potrzeba informacji, należy wykorzystać znane metody kompresji danych, umożliwiające spełnienie wymagań dotyczących szybkości przetwarzania danych pomiarowych. W pracy podano odnośne wzory służące do obliczeń w takim adaptacyjnym systemie pomiarowym.

Adaptive iterative deblending of simultaneous source seismic data based on sparse inversion

100%

Wei Y. , Cao J. , Huang X. , Chen X. , Cai Z.

tom Vol. 69, no. 2

497--507

Deblending of simultaneous-source seismic data is becoming more popular in seismic exploration since it can greatly improve the efciency of seismic acquisition and reduce acquisition cost. At present, the deblending methods of simultaneous-source seismic data are mainly divided into two types: fltering method and sparse inversion method. Compared with the fltering method, the sparse inversion method has higher precision, but the selection of its parameter value mainly depends on experience, which is not suitable for large-scale seismic data processing. In this paper, an adaptive iterative deblending method based on sparse inversion is proposed. By improving the original iterative solution method of regularization inversion model, the efective signal and blending noise are weakened simultaneously in the iterative process, so that the energy intensity of blending noise is consistent with that of the efective signal in each iterative, so as to ensure the consistency of the regular parameter calculation method of each iteration. By analyzing the distribution of coefcients in the curvelet domain of pseudo-deblending data and blending noise, it is concluded that the value of regular parameters is the maximum amplitude of residual pseudo-deblending data in the curvelet domain multiplied by a coefcient between 0 and 1. In the process of iterative deblending, the regularized parameters are obtained adaptively from the data itself. It not only ensures the accuracy of the calculation results, but also improves the calculation efciency, which is suitable for large-scale seismic data processing.