arXiv subjects

Leszek Nowosielski

Publications and source records attributed to Leszek Nowosielski.

4 recordsLinked to original sources

arXiv2025

Power angular spectrum versus Doppler spectrum -- Measurements and analysis

In this paper, we present an empirical verification of the method of determining the Doppler spectrum (DS) from the power angular spectrum (PAS). Measurements were made for the frequency of 3.5 GHz, under non-line-of-sight conditions in suburban areas characteristic of a university campus. In the static scenario, the measured PAS was the basis for the determination of DSs, which were compared with the DSs measured in the mobile scenario. The obtained results show that the proposed method gives some approximation to DS determined with the classic methods used so far.

eess.SP↗

arXiv2018

BER measurements in the evaluation of operation correctness of VSAT modem traffic interfaces

This paper presents using bit error rate (BER) measurements to evaluate operation correctness of traffic (input-output) interfaces in modem of very small aperture terminal (VSAT). Such functional tests are carried out, for example, when purchasing communication equipment for armed forces. Generally, available standards do not describe measurement procedures in this area. In this case, accredited laboratories should develop dedicated assessment methodologies. In this paper, we show the methodology for the VSAT modems, which is based on the BER measurements.

cs.IT↗

arXiv2018

Correlation properties of signal at mobile receiver for different propagation environments

An issue of the parameter selection in various branches of a multi-antenna receiver system determines its effectiveness. A significant effect on these parameters are correlation properties of received signals. In this paper, the assessment of the signal correlation properties for different environmental conditions is presented. The obtained results showed that depending on the receiver speed, the adaptive selection of the delays in the different RAKE receiver branches provide minimization of the correlation between the signals. Particularly low levels of the signal correlation could be obtained in complex propagation environments such as urban and bad urban.

cs.IT↗

arXiv2018

Modeling the distribution of the arrival angle based on transmitter antenna pattern

An angular distribution of received signals has a significant impact on their spectral and correlational properties. Most of angular dispersion models do not consider antenna patterns. The developed procedure for determining the propagation path parameters enables a wide range of assessment of the impact of the propagation environment on the received signal properties. In contrast to the other models, this procedure is based on a geometrical structure, which parameters are defined on the basis of power delay profile or spectrum This modeling method allows also the power radiation pattern (PRP) of the transmitting antenna. The aim of the paper is to present the influence of the transmitter antenna PRP on the scattering propagation paths that arrive at the receiver. This analysis is realized on the basis of simulations studies using the developed procedure. Presented in this paper procedure maps the effects of propagation phenomena that predominate in an azimuth plane.

cs.IT↗