Mahmoud Abdullahi | University of Surrey (original) (raw)

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Papers by Mahmoud Abdullahi

2016 International Symposium on Wireless Communication Systems (ISWCS), 2016

Proceedings of the 7th International Conference on Computing Communication and Networking Technologies, 2016

Switching off network links/nodes for energy efficiency is no longer a new thing to the Internet ... more Switching off network links/nodes for energy efficiency is no longer a new thing to the Internet community but the important thing is its dynamic deployment. Up until now, the normal paradigm in energy aware traffic engineering is to deploy a pruned network topology based on historic traffic matrices or to manipulate, on the fly, the traffic routings based on some network metrics. However, these schemes could be inimical to the diurnal traffic. We therefore propose an Energy Saving Scheme (ESS) that is based on the current network traffic and is not limited to the off-peak period for its operation. It employs the principle of using only links whose sleeping/wake-up operation are non-disruptive during peak periods. Using the publicly accessible traffic traces of both GEANT and Abilene networks respectively, our results show a substantial amount of energy-savings in both peak and off-peak periods. More importantly, by deploying a non-disruptive approach during the peak period, we show...

A few years ago the communications industry announced a plan for the introduction of fifth-genera... more A few years ago the communications industry announced a plan for the introduction of fifth-generation (5G) wireless network. Unlike the previous successive generations which are a slight iteration of their predecessor technologies, 5G is going to be a major leap in the communication industry by introducing several new applications, which have never been covered by any telecommunication standards. Example of such applications are the Ultra-reliable low-latency communications, vehicle-to-everything and the internet of things. And in order to meet these new challenges, researchers world over are seeking new methods and techniques that will make the 5G revolution a reality. Index modulation for multicarrier systems which is the focus of this thesis is one of the new physical layer technologies that hold the promise of improving data rates without increasing the system bandwidth, as well as improves energy efficiency. Orthogonal frequency division multiplexing with index modulation, for ...

arXiv: Signal Processing, 2018

Index modulation (IM) has recently emerged as a promising concept for spectrum and energy-efficie... more Index modulation (IM) has recently emerged as a promising concept for spectrum and energy-efficient next generation wireless communications systems since it strikes a good balance among error performance, complexity, and spectral efficiency. IM technique, when applied to multicarrier waveforms, yields the ability to convey the information not only by M-ary signal constellations as in conventional multicarrier systems but also by the indexes of the subcarriers, which are activated according to the incoming bit stream. Although IM is well studied for OFDM based systems, FBMC with index modulation has not been thoroughly investigated. In this paper, we shed light on the potential and implementation of IM technique for QAM based FBMC system. We start with a mathematical model of the IM based QAM-FBMC system (FBMC/QAM-IM) along with the derivation of interference terms at the receiver due to channel distortions and noise. The interference terms including the ones introduced by the multip...

2016 European Conference on Networks and Communications (EuCNC), 2016

The future wireless network demands higher-level modulation to enhance spectral efficiency, which... more The future wireless network demands higher-level modulation to enhance spectral efficiency, which means a symbol-to-bit soft demapper with much higher complexity is required if using conventional demapping algorithm. In this paper, we proposed a low-complexity soft demapper for 256 QAM. Simulations show that it achieves much lower complexity with the negligible performance degradation in comparison with max-log-MAP demapper.

arXiv: Signal Processing, 2017

Transmission of complex-valued symbols using filter bank multicarrier systems has been an issue d... more Transmission of complex-valued symbols using filter bank multicarrier systems has been an issue due to the self-interference between the transmitted symbols both in the time and frequency domain (so-called intrinsic interference). In this paper, we propose a novel low-complexity interference-free filter bank multicarrier system with QAM modulation (FBMC/QAM) using filter deconvolution. The proposed method is based on inversion of the prototype filters which completely removes the intrinsic interference at the receiver and allows the use of complex-valued signaling. The interference terms in FBMC/QAM with and without the proposed system are analyzed and compared in terms of mean square error (MSE). It is shown with theoretical and simulation results that the proposed method cancels the intrinsic interference and improves the output signal to interference plus noise ratio (SINR) at the expense of slight enhancement of residual interferences caused by multipath channel. The complexity ...

2016 International Symposium on Wireless Communication Systems (ISWCS), 2016

Proceedings of the 7th International Conference on Computing Communication and Networking Technologies, 2016

Switching off network links/nodes for energy efficiency is no longer a new thing to the Internet ... more Switching off network links/nodes for energy efficiency is no longer a new thing to the Internet community but the important thing is its dynamic deployment. Up until now, the normal paradigm in energy aware traffic engineering is to deploy a pruned network topology based on historic traffic matrices or to manipulate, on the fly, the traffic routings based on some network metrics. However, these schemes could be inimical to the diurnal traffic. We therefore propose an Energy Saving Scheme (ESS) that is based on the current network traffic and is not limited to the off-peak period for its operation. It employs the principle of using only links whose sleeping/wake-up operation are non-disruptive during peak periods. Using the publicly accessible traffic traces of both GEANT and Abilene networks respectively, our results show a substantial amount of energy-savings in both peak and off-peak periods. More importantly, by deploying a non-disruptive approach during the peak period, we show...

A few years ago the communications industry announced a plan for the introduction of fifth-genera... more A few years ago the communications industry announced a plan for the introduction of fifth-generation (5G) wireless network. Unlike the previous successive generations which are a slight iteration of their predecessor technologies, 5G is going to be a major leap in the communication industry by introducing several new applications, which have never been covered by any telecommunication standards. Example of such applications are the Ultra-reliable low-latency communications, vehicle-to-everything and the internet of things. And in order to meet these new challenges, researchers world over are seeking new methods and techniques that will make the 5G revolution a reality. Index modulation for multicarrier systems which is the focus of this thesis is one of the new physical layer technologies that hold the promise of improving data rates without increasing the system bandwidth, as well as improves energy efficiency. Orthogonal frequency division multiplexing with index modulation, for ...

arXiv: Signal Processing, 2018

Index modulation (IM) has recently emerged as a promising concept for spectrum and energy-efficie... more Index modulation (IM) has recently emerged as a promising concept for spectrum and energy-efficient next generation wireless communications systems since it strikes a good balance among error performance, complexity, and spectral efficiency. IM technique, when applied to multicarrier waveforms, yields the ability to convey the information not only by M-ary signal constellations as in conventional multicarrier systems but also by the indexes of the subcarriers, which are activated according to the incoming bit stream. Although IM is well studied for OFDM based systems, FBMC with index modulation has not been thoroughly investigated. In this paper, we shed light on the potential and implementation of IM technique for QAM based FBMC system. We start with a mathematical model of the IM based QAM-FBMC system (FBMC/QAM-IM) along with the derivation of interference terms at the receiver due to channel distortions and noise. The interference terms including the ones introduced by the multip...

2016 European Conference on Networks and Communications (EuCNC), 2016

The future wireless network demands higher-level modulation to enhance spectral efficiency, which... more The future wireless network demands higher-level modulation to enhance spectral efficiency, which means a symbol-to-bit soft demapper with much higher complexity is required if using conventional demapping algorithm. In this paper, we proposed a low-complexity soft demapper for 256 QAM. Simulations show that it achieves much lower complexity with the negligible performance degradation in comparison with max-log-MAP demapper.

arXiv: Signal Processing, 2017

Transmission of complex-valued symbols using filter bank multicarrier systems has been an issue d... more Transmission of complex-valued symbols using filter bank multicarrier systems has been an issue due to the self-interference between the transmitted symbols both in the time and frequency domain (so-called intrinsic interference). In this paper, we propose a novel low-complexity interference-free filter bank multicarrier system with QAM modulation (FBMC/QAM) using filter deconvolution. The proposed method is based on inversion of the prototype filters which completely removes the intrinsic interference at the receiver and allows the use of complex-valued signaling. The interference terms in FBMC/QAM with and without the proposed system are analyzed and compared in terms of mean square error (MSE). It is shown with theoretical and simulation results that the proposed method cancels the intrinsic interference and improves the output signal to interference plus noise ratio (SINR) at the expense of slight enhancement of residual interferences caused by multipath channel. The complexity ...