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Boualleg S.,University of Science and Technology Houari Boumediene | Haraoubia B.,University of Science and Technology Houari Boumediene | Nedil M.,Underground Communications Research Laboratory
IEEE Antennas and Propagation Society, AP-S International Symposium (Digest) | Year: 2015

Combining the capacities of multiple-input multiple-output (MIMO) technology in enhancing the achievable data rate and the space time coding in combating the Inter-symbol Interference due to the fading channel, this paper investigates such an issue for MIMO Wireless Underground channels. Moreover the robustness of the Least-Squares (LS) and Minimum Mean Square Error (MMSE) channel estimation methods is assessed under different modulation schemes. © 2015 IEEE. Source


El Azhari M.,Underground Communications Research Laboratory | Nedil M.,Underground Communications Research Laboratory | Salih Alj Y.,Al Akhawayn University | Ben Mabrouk I.,University of Tabuk | And 2 more authors.
Proceedings of 2015 International Conference on Electrical and Information Technologies, ICEIT 2015 | Year: 2015

In this paper, the off-body performance of a single-input single-output (SISO) system was evaluated in Non-Line-of-Sight (NLOS) situations and compared with measurements done with a clear Line of Sight (LOS) link. The obstructed link study takes into account the human shadowing effect, usually caused by close by miners interrupting the transmitter-receiver link. Measurement campaigns were performed using Monopole antennas in an underground gold mine. The off-body channels were characterized in terms of the channel impulse response, RMS delay spread, and coherence bandwidth. The channel capacity was determined using the well-known Shannon formula for LOS and NLOS situations. The variation of the channel parameters in the different measurement scenarios was analyzed. © 2015 IEEE. Source


Ben Mabrouk I.,Underground Communications Research Laboratory | Talbi L.,Underground Communications Research Laboratory | Nedil M.,Underground Communications Research Laboratory | Hettak K.,Communications Research Center Canada
Journal of Electromagnetic Waves and Applications | Year: 2012

This paper studies the effects caused by the presence of a human body on a multiple-input-multiple-output (MIMO) ultrawideband (UWB) communication system. It is very important to study the fading effects caused by the movement of a human body, since these effects become particularly significant when characterizing short-range channels. To address this issue, the wireless channel is measured over 7.5 GHz bandwidth using a 2×2 MIMO system in an underground mine containing a human body. Results suggest that human presence substantially affects both path gain and time dispersion parameters experienced by the link. It is demonstrated that larger K-factors (1.6 dB) can be attributed to the high losses associated with reflections caused by a human body, which in turn reduce the strength of the received scattered signal. Consequently, the presence of a mineworker should be considered when assessing the performance of an underground mine gallery wireless system. Source


Boualleg S.,University of Science and Technology Houari Boumediene | Haraoubia B.,University of Science and Technology Houari Boumediene | Nedil M.,Underground Communications Research Laboratory | Azzeddine S.,Underground Communications Research Laboratory | And 2 more authors.
IEEE Antennas and Propagation Society, AP-S International Symposium (Digest) | Year: 2014

Using space time block coding (STBC) to enhance the communication quality in underground environments may be of great interest. In this paper, by the aid of the simple maximum likelihood algorithm at the reception, the bit error rate performance of STBC scheme is investigated on a 2× 2 MIMO system within an underground gold mine environment. Taking Rayleigh channel as a reference, the performance in the specific indoor environment is compared to the SISO case when using BPSK and QPSK modulations. © 2014 IEEE. Source


Mabrouk I.B.,Underground Communications Research Laboratory | Nedil M.,Underground Communications Research Laboratory | Coulibaly Y.,Underground Communications Research Laboratory | Denidni T.,INRS - Institute National de la Recherche Scientifique
IET Microwaves, Antennas and Propagation | Year: 2012

In this study two measurement campaigns are presented, where two types of multiple input multiple output (MIMO) antennas are investigated in an underground mine environment, aiming to identify the optimal antenna technology that allows to improve the performance of MIMO system in terms of root mean square (RMS) delay spread, path loss and capacity. It is found that in such scatter-rich environment, for line of sight scenario the directional antennas have provided significant suppression of multipath, giving a reduction in received RMS delay spread, and a corresponding increase in the correlation, which consequently decrease the channel capacity. © 2012 The Institution of Engineering and Technology. Source

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