Adnan T.,University of New South Wales |
Masood A.,University of Engineering and Technology
2011 IEEE 3rd International Conference on Communication Software and Networks, ICCSN 2011 | Year: 2011
The paper describes the transmission of BPSK signals in an OFDM system with 64-point IFFT at transmitter and FFT at receiver. The channel over which transmission will take place is ISI Rayleigh fading channel given by 2 tap channel model with path delay [0, 0.5] μs. The sampling frequency of OFDM is to be kept at 20MHz. Cyclic prefix for OFDM is calculated for improving bandwidth efficiency of the system. First, the symbol error rate (SER) of un coded OFDM system is plotted as a function of SNR via simulation in MATLAB and then the result is compared with coded OFDM system's SER plot, where the coding is provided by 1/2 rate convolution encoder accompanied by viterbi decoder at the receiver side. © 2011 IEEE.
Nguyen C.H.,Vietnam Academy of Science and Technology |
Tran T.S.,Vietnam Academy of Science and Technology |
Pham D.P.,University of Engineering and Technology
Knowledge-Based Systems | Year: 2014
Computing with words and fuzzy linguistic rule based systems play important roles as they can find various significant applications based on simulating human capability. In fuzzy set approaches, words are mapped to fuzzy sets, on which work operations of the developed methodologies. The interpretability of the methodologies depends on how well word semantics is represented by fuzzy sets, which in practice are designed based on human-user's intuition. In these approaches there is no formal linkage of fuzzy sets with the inherent semantics of words to ensure the interpretability of fuzzy sets and, hence, fuzzy rules. Hedge algebras, as models of linguistic domains of variables, provide a formalism to generate triangular fuzzy sets of terms from their own semantics. This permits for the first time to design genetically terms along with their integrated triangular fuzzy sets and to construct effective fuzzy rule based classifiers. To answer the question if trapezoidal fuzzy sets can be used instead of triangular fuzzy sets in the above design method, in this study we introduce and develop the so-called enlarged hedge algebras, in which the concept of semantics core of words can be modeled. We show that these algebras provide a formal mechanism to design optimal words integrated with their trapezoidal fuzzy sets as well as fuzzy linguistic rule based classifiers to solve classification problems. Two case studies are examined to show the usefulness of the proposed algebras. © 2014 Elsevier B.V. All rights reserved.
Mullick A.K.,University of Engineering and Technology
Indian Concrete Journal | Year: 2012
Conservation of natural resources, reduction of greenhouse gases and environmental pollution, and utilization of waste materials are among the basic tenets of sustainable development. In case of concrete construction, these objectives are fulfilled by appropriate choice of binder systems and aggregate, which are elaborated in the paper. Particular attention is drawn to the use of ternary cement blends containing industrial wastes, bottom ash as fine aggregate and recycled aggregate in structural grade concrete. Examples of current construction practice in India and research initiatives are highlighted.
Ahmad S.,University of Engineering and Technology |
Zafrullah M.,University of Engineering and Technology
Journal of Modern Optics | Year: 2015
In this paper, the simulation of 60 GHz millimeter-wave radio over fiber link with 4-QAM OFDM modulation format at 40 Gb/s over 150 km SMF is proposed. The 60 GHz millimeter-wave signal is generated by the optical heterodyne method. Coherent detection has been used at the receiver to down-convert millimeter-wave signal to IF band. Introduction of the OFDM modulation in RoF-based system realizes the benefits of higher order modulations (such as 4-QAM, 16-QAM, etc.) to ensure the good spectral efficiency and multi-gigabit access. The performance of the system is analyzed by Q-factor and BER by which it can be shown that the best results are obtained at the input power of 10 dBm. The simulation results clearly demonstrate the feasibility of this 4-QAM OFDM RoF system over 150 km fiber link. © 2014 Taylor & Francis.
Asif R.,Friedrich - Alexander - University, Erlangen - Nuremberg |
Asif R.,University of Engineering and Technology |
Lin C.-Y.,Friedrich - Alexander - University, Erlangen - Nuremberg |
Holtmannspoetter M.,Friedrich - Alexander - University, Erlangen - Nuremberg |
Schmauss B.,Friedrich - Alexander - University, Erlangen - Nuremberg
Optics Express | Year: 2013
We numerically report on the complexity reduction of digital backward propagation (DBP) by utilizing correlative encoded transmission (dual-polarization quadrature duobinary) at a bit-rate of 112Gbit/s over 1640km fibe link. The single channel (N=1) and multi-channel (N=10) transmission performances are compared in this paper. In case of multichannel system, 10 transmitters are multiplexed with 25GHz channel spacing. The fibe link consists of Large Ae f f Pure-Silica core fibe with 20 spans of 82km each. No in-line optical dispersion compensator is employed in the link. The system performances are evaluated by monitoring the bit-error-ratio and the forward error correction limit corresponds to bit-error-ratio of 3.8×103. The DBP algorithm is implemented after the coherent detection and is based on the logarithmic step-size based splitstep Fourier method. The results depict that dual-polarization quadrature duobinary can be used to transmit 112Gbit/s signals with an spectral efficien y of 4-b/s/Hz, but at the same time has a higher tolerance to nonlinear transmission impairments. By utilizing dual-polarization quadrature duobinary modulation, comparative system performance with respect to dual-polarization 16-quadrature amplitude modulation transmission can be achieved with 60% less computations and with a step-size of 205km. © 2013 Optical Society of America.
Edwards R.M.,Loughborough University |
Khattak M.I.,University of Engineering and Technology
2010 Loughborough Antennas and Propagation Conference, LAPC 2010 | Year: 2010
As of September 2010 trends suggested that disruptive technologies were likely to include wireless communications devices integrated into clothing. A new set of antennas is required for Body-centric applications. Such antennas will form a key component in Body area networks (BANs) in which transmitters and receivers are co-located on the body, implanted under the skin, directly attached to the skin or integrated into clothing. Notable drivers are multimedia, medical and military applications. These drivers combined with the geo-sensitive facilitators of global positioning system (GPS), Galileo global navigation satellite system (GNSS), cellular, unlicensed 802.11x and short range technologies such as Bluetooth and UWB have made Body-centric antennas fundamental in achieving the desired low power signal budgets required. ©2010 IEEE.
Gondal I.A.,University of Engineering and Technology |
Sahir M.H.,University of Engineering and Technology
International Journal of Energy Research | Year: 2012
This paper analyses the transportation and delivery features of hydrogen as energy market evolves and approaches a fully functional Hydrogen economy. Initially physical aspects have been assessed that affect the flow of hydrogen through the existing pipeline infrastructure. Line pack and compressors are the only identified problems that need to be addressed. This is followed by an investigation into the mixing of hydrogen with natural gas gradually. It was revealed that a mix of up to 17% by volume does not have any significant effect, however higher concentration of hydrogen leads to a changeover of high-pressure grid pipelines as well as the end-user applications. It is suggested that initially hydrogen can be introduced in the distribution system, while emphasizing towards developing means for high-pressure transportation of hydrogen fuel gas. Government policies towards encouraging use of hydrogen in an evolving market is important for widespread and early assimilation in energy mix. Renewable sources of energy are recommended for distributed generation of hydrogen along the pipeline network. © 2011 John Wiley & Sons, Ltd.
Asif R.,University of Engineering and Technology |
Islam M.K.,University of Engineering and Technology |
Zafrullah M.,University of Engineering and Technology
Journal of the Optical Society of Korea | Year: 2013
We have numerically implemented a receiver side all-optical signal processing method, i.e. optical backward propagation (OBP), by dispersion compensating fiber (DCF) and non-linear compensator (NLC) devised by effective negative Kerr non-linear coefficient using two highly non-linear fibers (HNLFs). The method is implemented for the post-processing of fiber transmission impairments, i.e. chromatic dispersion (CD) and non-linearities (NL). The OBP module is evaluated for dual-polarization (DP) m-ary (m=4, 16, 32, 64, 256) quadrature amplitude modulation (QAM) in 112 Gbit/s coherent transmission over 1200 km standard single mode fiber (SMF). We have also investigated an intensity limited optical backward propagation module (IL-OBP) by using a self-phase modulation-based optical limiter with an appropriate pre-chirping to compensate for the intensity fluctuations in the transmission link. Our results show that in highly non-linear sensitive 256QAM transmission, we have observed a 66% increase in the transmission distance by implementing IL-OBP as compared to conventional OBP.
Al-Gamal S.A.,University of Engineering and Technology
Journal of Hydrology | Year: 2011
A comprehensive understanding of the groundwater dynamics of a transboundary aquifer system is highly needed for any successful transboundary cooperation policy. Moreover, an analysis of the NWSAS can be of particular interest for policy makers and researchers. This paper aims to reveals and to assess the renewability of North-Western Sahara Aquifer System (NWSAS) as one of the major transboundary multi-layered aquifer system, in North Africa, shared by Algeria, Tunisia, and Libya and is often referred to as the Système Aquifère du Sahara Septentrional (SASS). The paper is primarily intended for exploring whether it receives a considerable fraction of modern water as recharge or it is at risk of being depleted and excessively pumped, where the main challenge for NWSAS, is that it should be abstracted rationally for equitable use. Environmental isotopes data of δ18O, δ2H, 3H, 14C as well as characteristics of d-excess are used to illustrate whether NSWAS is renewable or non-renewable resource. Geochemical, hydrological and statistical evidences supporting the renewability of NWSAS are provided through pairs of cross-plots. The study has clearly indicated that NWSAS is receiving a considerable fraction of modern water as recharge to the aquifer because of the following reasons: Firstly, the moderately depleted delta values of δ18O and δ2H of water from Sahara Atlas in Algeria and the Dahar and the Dj. Nefoussa in Tunisia and Libya with δ18O content (-6.0‰ to -5.0‰) compared with that of palaeowater (-7.0‰ to -9.0‰) indicate an appreciable fraction of modern water recharging NWSAS. This appreciable fraction of modern water should be attributed to originate from the present-day precipitation (-6.5‰). Secondly, the presence of significant amount of 14C>2% and 3H>5 TU, frequently found in data should be attributed to a mixing with shallow and modern water, where old water practically contains no 14C. The foregoing facts are in good agreement with the results of conventional hydrologic approach. This would contradict the assumption that the NWSAS is non-renewable water resource. In this context, the NWSAS is being located in one of the driest regions on the planet; these huge resources have been recognized to be of great importance to the socio-economic development of its riparian countries. So the present paper addresses the necessity of identifying specific cooperation problems which evolve out of these hydro geological attributes and prevalent use patterns. Accordingly, the description of NWSAS as non-renewable, devoid of any meaningful recharge, a rather stagnant water body, disconnected from any surface water body in addition to its classification as " non-renewable" would therefore be misleading and represents one of the most obvious inaccuracy as well. © 2010 Elsevier B.V.
Nadeem L.,University of Engineering and Technology |
Asif R.,University of Engineering and Technology
Frontiers of Optoelectronics | Year: 2013
In this paper, a technique was numerically implemented to generate a frequency shift keying (FSK) radio-over-fiber (RoF) signal in optical domain. Due to the oscillator free generation of FSK signal, this scheme is highly stable with reduced complexity and extremely cost effective. The remote heterodyne detection method was used to detect the signal, where beating occurs to detect the FSK signal. With this scheme, it is able to efficiently generate FSK signal in the range of 60 and 75 GHz at 8 Gbit/s and effectively transmit it over 80 km link without degrading the signal shape and quality. The nonlinear threshold (NLT) point of the system has also been numerically analyzed to estimate the nonlinear tolerance of the system. Besides, the impact of transmission distance and polarization mode dispersion (PMD) was evaluated. Furthermore, the wavelength reuse for the uplink was implemented in the scheme by reusing the same wavelength for uplink that was used for signal generation at downlink. The whole process was performed in optical domain. Thus this scheme is very cost effective as the overall architecture of RoF system is simplified. © 2013 Higher Education Press and Springer-Verlag Berlin Heidelberg.