S.S. Ikki

Université du Québec à Montréal, Montréal, Quebec, Canada

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Publications (31)25.61 Total impact

  • EUSIPCO2014; 09/2014
  • R. Mesleh, S.S. Ikki, O. Amin
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    ABSTRACT: Performance analysis of multi-hop wireless networks with non-regenerative relays over Nakagami-m fading channels in the presence of co-channel interference is presented in this paper. In the analysis, an arbitrary number of independent and identically distributed Nakagami-m interferers will be considered. Closed-form expression for the cumulative distribution function (CDF) of the upper bounded end-to-end signal-to-interference-plus-noise ratio (SINR) at the destination is given. The obtained CDF is then considered to study the average bit error probability (ABEP). Furthermore, an approximate expression for the CDF of the instantaneous end-to-end SINR is derived, based on which simple and general asymptotic expression for the error probability is presented and discussed. The derived asymptotic equation is shown to reduce to the already published equation in Rayleigh fading, which corroborate the exactness of the derived analysis. Besides, analytical comparison between amplify-and-forward and decode-and-forward multi-hop systems in terms of ABEP is provided. Optimisation of the power allocation at the network's transmit nodes and the positioning of the relays are studied as well. It is shown that optimum power allocation achieves only coding gain, whereas optimising relay locations yields diversity gains as well as coding gain.
    IET Communications 03/2014; 8(4):483-491. · 0.72 Impact Factor
  • Source
    K.B. Fredj, S.S. Ikki, S. Aissa
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    ABSTRACT: This paper studies the performance of a two-way relay-based communication system with opportunistic relay selection in Nakagami-m fading environments. The authors consider a two-way wireless communication system where two nodes, acting as sources and using different modulation schemes for transmission, are unable to exchange data because of deep fading on their direct link and proceed via L relay terminals. They provide closed-form expression for the probability density function of the link between the 'selected' best relay and each source, and use this result to derive a closed-form expression for the average symbol error probability which, to the best knowledge of the authors, has never been done before. This result is further approximated for the high signal-to-noise ratio regions and used to develop closed-form expressions for the optimised power allocated to each node involved in the communication process. The authors asset their formulae with numerical results and interpretations to complete this work.
    IET Communications 01/2014; 8(9):1626-1636. · 0.72 Impact Factor
  • S.S. Ikki, R. Mesleh, S. Boussakta
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    ABSTRACT: Amplify-and-forward (AF) relaying with multi-branch dual-hop relays in independent non-identical generalized Gamma fading channels with multiple antennas at the destination is addressed. We consider orthogonal relaying and study conventional cooperative systems where all relays participate in the relaying phase as well as opportunistic cooperative systems where only the best relay participates in the relaying phase. An expression for the approximate probability density function (PDF) of the total instantaneous signal-to-noise ratio (SNR) at the destination is derived. Subsequently, expression for the asymptotic average error rate is presented. The results provided are fairly simple and general for arbitrary values of the fading severity parameters. It is shown that opportunistic relaying does not necessarily outperform the conventional approach in terms of coding gain under equal energy allocation as in the Rayleigh fading case. Simulation results verify the tightness of the proposed analytical expressions in the high SNR region.
    Signal Processing Advances in Wireless Communications (SPAWC), 2013 IEEE 14th Workshop on; 01/2013
  • A.H. Forghani, S.S. Ikki, S. Aissa
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    ABSTRACT: In this paper, we study the performance of opportunistic amplify-and-forward (AF) multihop multibranch relaying networks operating in the presence of cochannel interference (CCI). We obtain exact and upper bound expressions for the end-to-end signal-to-interference-plus-noise ratio (SINR), assuming transmissions over independent nonidentical Rayleigh fading channels. Afterward, the cumulative distribution function (cdf) and the probability density function (pdf) of the upper bound end-to-end SINR are investigated. According to these statistics, we obtain a lower bound closed-form expression for the outage probability. Furthermore, an approximate expression for the pdf of the end-to-end SINR is derived. Subsequently, simple expressions for the approximate error and outage probabilities are provided. These expressions deliver more understanding on the effect of the system parameters. Moreover, we address the optimization of the power allocation among the transmit nodes to enhance the overall system performance. As an optimal solution for the resource-allocation problem at hand, the adaptive power allocation minimizes the error probability under constraint on the aggregate power over the branch with the maximum SINR. It is shown that by applying the energy obtained through the optimization process, the performance of the network is improved significantly. Eventually, the accuracy of the analysis is validated by comparing the numerical results with Monte Carlo simulations, and insightful discussions are provided.
    IEEE Transactions on Vehicular Technology 01/2013; 62(7):3437-3443. · 2.06 Impact Factor
  • Raed Mesleh, Salama Said Ikki, Osama Amin, Said Boussakta
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    ABSTRACT: In this paper, performance and optimization study of multi-hop wireless system with amplify and forward (AF) relays over Nakagami-m fading channels and in the presence of co-channel interference is considered. Arbitrary number of independent and identically distributed Nakagami-m interferers is assumed in the analysis. The cumulative distribution function (CDF) of the upper bounded end-to-end signal-to-interference-plus-noise ratio (SINR) at the destination is calculated in closed-form. The obtained CDF is then used to study the end-to-end average bit error probability (ABEP). As well, approximate expression for the CDF of the instantaneous end-to-end SINR is derived. Based on this, simple and general asymptotic expression for the error probability is presented and discussed. Finally, optimizing power allocation at the transmit nodes and the positioning of the relays are studied. Obtained results revealed that optimum power allocation slightly enhances the performance, whereas optimizing relay locations yields significant performance enhancement. Further improvement is shown to be achieved through joint power and positions optimization.
    Personal Indoor and Mobile Radio Communications (PIMRC), 2013 IEEE 24th International Symposium on; 01/2013
  • S.S. Ikki, P. Ubaidulla, S. Aissa
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    ABSTRACT: A study of the effects of co-channel interference on a multirelay system with decode-and-forward (DF) protocol is presented. Orthogonal relaying is considered, and all relays that correctly decode the message in the broadcasting phase participate in the adaptive relaying phase. First, the effective signal-to-interference-plus-noise ratio (SINR) at the receiver is derived. Then, considering outage as the performance metric, we obtain exact closed-form expression for the outage probability. Simple and general asymptotic expressions for the outage probability, which explicitly show the coding and the diversity gains, are also derived and discussed. Furthermore, we present optimal energy-allocation schemes for minimizing outage under different resource constraints. Monte Carlo simulations are further provided to confirm the analytical results and illustrate the outage performance for different interference conditions and optimization schemes.
    IEEE Transactions on Vehicular Technology 01/2013; 62(2):896-902. · 2.06 Impact Factor
  • R. Mesleh, S.S. Ikki
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    ABSTRACT: Spatial modulation (SM) is a multiple-input multiple-output (MIMO) transmission scheme that draws momentous attention lately due to its reported performance enhancements over other MIMO techniques. However, a major drawback of SM system is that the achieved diversity gain is limited to the number of receive antennas and poor performance is reported for small number of receive antennas. Therefore, it is the aim of this paper to study the performance of SM with multiple decode and forward (DF) relays in which the relays that correctly detect the source signal forward the decoded message to the destination in pre-determined orthogonal channels. A closed form expression of the pair wise error probability (PEP) is obtained for a system consisting of two transmit antennas, multiple DF relays and single receive antenna. As well, asymptotic expression for the PEP at high signal to noise ratio (SNR) is derived. It is shown that significant performance enhancements can be achieved and the derived analysis is validated through Monte Carlo simulation results.
    Wireless Communications Letters, IEEE. 01/2013; 2(4):423-426.
  • Yanju Gu, S.S. Ikki, S. Aissa
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    ABSTRACT: This paper investigates the impacts of co-channel interference and outdated channel state information (CSI), two main issues in practical operating environment, on the performance of opportunistic decode-and-forward cooperative networks. First, the distribution function of the effective signal-to-interference-plus-noise ratio at the end receiver is derived. Then, exact closed-form expressions for the error and outage probabilities are obtained. Furthermore, simple asymptotic expressions for the error probability, which explicitly show the coding and the diversity gains, are derived and discussed. In particular, it is demonstrated that the diversity order of the system is reduced to unity when CSI is outdated, and to zero when the ratio of the interference energy to the signal energy is constant.
    IEEE Communications Letters 01/2013; 17(10):1948-1951. · 1.16 Impact Factor
  • Raed Mesleh, Salama S. Ikki
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    ABSTRACT: In this paper, spatial modulation (SM) is considered in a cooperative communication system and the effect of imperfect channel estimation on the overall system performance is analyzed. SM is a multiple-input multiple-output (MIMO) technique that considers the multiple transmit antennas as an added constellation points and utilizes them to boost the spectral efficiency. In our analysis, a wireless communication system, where a source communicating with a destination through a direct link and multiple decode and forward (DF) relays, is considered. Imperfect channel knowledge is assumed at each relay and at the destination node. In cooperative mode, only the relays that correctly decode the source signal forward the decoded message to the destination. A closed form expression of the pair wise error probability (PEP) is obtained for a system consisting of two transmit antennas, multiple DF relays and single receive antenna and a tight upper bound is given for the average error probability. As well, asymptotic expression for the PEP at high signal to noise ratio (SNR) is derived.
    Personal Indoor and Mobile Radio Communications (PIMRC), 2013 IEEE 24th International Symposium on; 01/2013
  • Raed Mesleh, Salama S. Ikki
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    ABSTRACT: Space shift keying (SSK) is a multiple-input, multiple-output system where the indices of the transmit antennas form the constellation symbols and no other data symbol is transmitted. In this paper, amplify-and-forward (AF) multiple-input, multiple-output relaying techniques with an SSK system are proposed and analysed. Single and multiple relays are located between the source and the destination and used to forward the transmitted messages from the source to the destination. Conventional AF relaying in which all relays amplify their received signal and forward it to the destination at specific time slot and opportunistic AF relaying where only the best relay is activated and all other relays are kept silent are considered. The receiver, with a single receive antenna, applies optimum detector to retrieve the transmitted information bits. Closed-form bit error ratio expressions are provided for a source equipped with two transmit antennas. Additionally, a good approximate upper bound is derived for higher number of transmit antennas. The analytical results are validated through Monte Carlo simulation results. It is revealed that multiple relays can be considered to significantly enhance the performance of SSK system, and the diversity gain equals the number of existing relays. Copyright © 2013 John Wiley & Sons, Ltd.
    Transactions on Emerging Telecommunications Technologies. 01/2013;
  • Source
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    ABSTRACT: In this article, space shift keying (SSK) modulation is used to study a wireless communication system when multiple relays are placed between the transmitter and the receiver. In SSK, the indices of the transmit antennas form the constellation symbols and no other data symbol are transmitted. The transmitter and the receiver communicate through a direct link and the existing relays. In this study, two types of relays are considered. Conventional amplify and forward relays in which all relays amplify their received signal and forward it to the destination in a round-robin fashion. In addition, decode and forward relays in which the relays that correctly detect the source signal will forward the corresponding fading gain to the destination in pre-determined orthogonal time slots are studied. The optimum decoder for both communication systems is derived and performance analysis are conducted. The exact average bit error probability (ABEP) over Rayleigh fading channels is obtained in closed-form for a source equipped with two transmit antennas and arbitrary number of relays. Furthermore, simple and general asymptotic expression for the ABEP is derived and analyzed. Numerical results are also provided, sustained by simulations which corroborate the exactness of the theoretical analysis. It is shown that both schemes perform nearly the same and the advantages and disadvantages of each are discussed.
    Journal on Advances in Signal Processing 09/2012; · 0.81 Impact Factor
  • Source
    Salama S. Ikki, Raed Mesleh
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    ABSTRACT: In this letter, accurate performance analysis of wireless communication system adopting Space Shift Keying (SSK) modulation scheme is introduced. More specifically, the performance of SSK system consisting of N_T transmit and N_R receive antennas with Maximum-Likelihood (ML) detection and imperfect Channel State Information (CSI) at the receiver is studied. The exact Average Bit Error Probability (ABEP) over Rayleigh fading channels is obtained in closed-form for N_T=2 and arbitrary N_R; while union upper bound is used to compute the ABEP when N_T>2 and arbitrary N_R. Furthermore, simple and general asymptotic expression for the ABEP is derived and analyzed. Numerical results are also provided, sustained by simulations which corroborate the exactness of the theoretical analysis.
    IEEE Communications Letters 01/2012; 16(2):228-230. · 1.16 Impact Factor
  • S.S. Ikki, S. Aissa
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    ABSTRACT: A study of the effect of cochannel interference on the performance of multihop wireless networks with amplify-and-forward (AF) relaying is presented. Considering that transmissions are performed over Rayleigh fading channels, first, the exact end-to-end signal-to-interference-plus-noise ratio (SINR) of the communication system is formulated and upper bounded. Then, the cumulative distribution function (cdf) and probability density function (pdf) of the upper bounded end-to-end SINR are determined. Based on those results, closed-form expression for the error probability is obtained. Furthermore, an approximate expression for the pdf of the instantaneous end-to-end SINR is derived, and based on this, a simple and general asymptotic expression for the error probability is presented and discussed. In addition, the ergodic capacity of multihop wireless networks in the presence of external interference is studied. Moreover, analytical comparisons between AF and decode-and-forward (DP) multihop in terms of error probability and ergodic capacity are presented. Finally, optimization of the power allocation at the network's transmit nodes and the positioning of the relays are addressed.
    IEEE Transactions on Vehicular Technology 01/2012; 61(2):566-573. · 2.06 Impact Factor
  • S.S. Ikki, S. Aissa
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    ABSTRACT: The performance of dual-hop communication over independent and non-identical Nakagami-m fading channels in the presence of co-channel interference is investigated. Specifically, an upper-bound of the equivalent signal-to-interference-plus-noise ratio (SINR) at the destination is introduced. Then, the cumulative distribution function (CDF) and the probability density function (PDF) of the upper bounded SINR are obtained. Moreover, simple, yet general, asymptotic expression for the error probability is presented and discussed. Besides, with the goal to minimize the asymptotic average error probability of the system under study, we investigate three optimization schemes, namely, adaptive power allocation under fixed location for the relay, optimal relay positioning with fixed power allocation, and joint optimization of the power allocation and relay location under transmit power constraint. Results show that optimum power allocation brings only coding gain, while the optimum relay location scheme yields diversity gains as well.
    IEEE Communications Letters 01/2012; 16(8):1149-1152. · 1.16 Impact Factor
  • S.S. Ikki, S. Aissa
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    ABSTRACT: Amplify-and-forward (AF) relaying with multi-branch dual-hop relays in independent non-identical Weibull fading channels with multiple antennas at the destination is addressed. The authors consider orthogonal relaying and study conventional cooperative systems where all relays participate in the relaying phase as well as opportunistic cooperative systems where only the best relay participates in the relaying phase. An expression for the approximate probability density function (PDF) of the total instantaneous signal-to-noise ratio (SNR) at the destination is derived. Subsequently, expressions for the asymptotic average error rate and the outage probability are presented. The results provided are fairly simple and general for arbitrary values of the fading severity parameters. It is shown that opportunistic relaying does not necessarily outperform the conventional approach in terms of coding gain under equal energy allocation as in the Rayleigh fading case. Simulation results verify the tightness of the proposed analytical expressions in the high SNR region.
    IET Communications 01/2012; 6(2):165-171. · 0.72 Impact Factor
  • A.H. Forghani, S.S. Ikki, S. Auissa
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    ABSTRACT: In this paper, the performance of opportunistic amplify-and-forward multi-hop multi-branch relaying systems operating in the presence of co-channel interferences is investigated. Considering transmissions over independent non-identical Rayleigh fading channels, exact and upper-bound expressions for the end-to-end signal-to-interference-plus-noise ratio (SINR) are obtained. Then, the cumulative distribution function (CDF) and the probability density function (PDF) of the upper bounded SINR are studied. Based on these statistics, the system's outage probability is analyzed in closed form. Moreover, we derive an approximate expression for the PDF of the instantaneous end-to-end SINR. Following that, simple expressions for the approximate error and outage probabilities are presented and discussed. The accuracy of the analysis is validated by comparing the numerical results with Monte Carlo simulations, and insightful discussions are provided.
    Communications (ICC), 2012 IEEE International Conference on; 01/2012
  • S.S. Ikki, S. Aissa
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    ABSTRACT: In this work, we analyze the performance of decode-and-forward cooperative diversity networks with imperfect channel estimation and co-channel interference. Orthogonal relaying is considered and all relays that correctly decode the source message in the broadcasting phase participate in the relaying phase. First, the output signal-to-interference-plus-noise ratio (SINR) at the destination is derived. Then, considering error and outage as the performance metrics, we obtain exact closed-form expressions for the error and outage probabilities. Simple and general asymptotic expression for the error probability, which explicitly shows the coding and the diversity gains, is also derived and discussed.
    Wireless Communications Letters, IEEE. 01/2012; 1(5):436-439.
  • S.S. Ikki
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    ABSTRACT: In this study, the authors examine the effect of a channel-estimation error on the error and outage probabilities of a multi-relay system with amplify-and-forward relaying over a frequency-flat Rician fading channel. The authors consider orthogonal relaying and study both conventional cooperative systems (i.e. all relays participate in the relaying phase) and opportunistic cooperative systems (i.e. only the best relay participates in the relaying phase). Based on the derivation of an effective signal-to-noise ratio (SNR) at the destination node taking into account channel-estimation error, the authors obtain closed-form expressions for error and outage probabilities in a high SNR regime. Such closed-form solutions are highly desirable because they allow for rapid and efficient evaluation of system performance. Computer simulations are used to validate the authors' analytical results.
    IET Signal Processing 01/2012; 6(6):577-583. · 0.71 Impact Factor
  • S.S. Ikki, S. Aissa
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    ABSTRACT: In this letter, we study the effect of channel estimation errors on the reception reliability of two-way relaying. For a network with two users that exchange information with each other through multiple amplify-and-forward relays, we investigate a single-relay selection scheme. Since the communication is two-way, the selection scheme aims at optimizing the worse performance of the two communication tasks between the pair of users. The signal-to-noise ratio (SNR) at the users' nodes of the relaying network is formulated and upper bounded. Then, the probability density function (PDF) of the upper bounded SNRs are determined. Subsequently, expressions for the error probabilities are obtained. Furthermore, an approximate PDF of the output instantaneous SNRs are derived, based on which simple and general asymptotic expressions for the error probabilities are presented and discussed. Numerical and simulation results are provided to verify the analysis and compare the performance of the two-way relaying network for different operating conditions and scenarios.
    IEEE Communications Letters 01/2012; 16(7):956-959. · 1.16 Impact Factor

Publication Stats

115 Citations
25.61 Total Impact Points

Institutions

  • 2012–2013
    • Université du Québec à Montréal
      Montréal, Quebec, Canada
    • Newcastle University
      • School of Electrical and Electronic Engineering
      Newcastle-on-Tyne, England, United Kingdom
    • Institut national de la recherche scientifique
      Québec, Quebec, Canada
    • INRS
      Lutetia Parisorum, Île-de-France, France
  • 2011
    • University of British Columbia - Vancouver
      • Department of Electrical and Computer Engineering
      Vancouver, British Columbia, Canada
  • 2010–2011
    • University of Waterloo
      • Department of Electrical & Computer Engineering
      Waterloo, Ontario, Canada
  • 2009
    • Memorial University of Newfoundland
      St. John's, Newfoundland and Labrador, Canada