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  • 51.
    Berggren, Fredrik
    et al.
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Ben Slimane, Slimane
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Power Allocation for a Simple Successive Interference Cancellation Scheme in a Multi-Rate DS-CDMA System2002Inngår i: 2002 IEEE INTERNATIONAL CONFERENCE ON COMMUNICATIONS, VOLS 1-5, CONFERENCE PROCEEDINGS, New York: IEEE , 2002, s. 351-355Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We investigate a multi-rate receiver utilizing soft feedback successive interference cancellation. To be able to meet the QoS requirements for each user, the multiuser detection is done in conjunction with power control. For this, we introduce a power control scheme that takes into account the respective QoS requirements and the impact of imperfect interference cancellation. We derive the minimum power solution, from which distributed iterative power control algorithms are suggested. It is found that the rate of convergence of the power control can be accelerated if the cancellation efficiency parameter can be directly incorporated into the power update. We also address the capacity resulting from this receiver in terms of the notion of effective bandwidth [1].

  • 52.
    Berggren, Fredrik
    et al.
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Ben Slimane, Slimane
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Successive Interference Cancellation in Multi-Rate DS-CDMA Systems2003Inngår i: PIMRC 2003: 14TH IEEE 2003 INTERNATIONAL SYMPOSIUM ON PERSONAL, INDOOR AND MOBILE RADIO COMMUNICATIONS PROCEEDINGS, VOLS 1-3 2003 / [ed] Gong K, Niu ZH, Beijing: PUBLISHING HOUSE ELECTRONICS INDUSTRY , 2003, s. 1752-1756Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this work, a linear DS-CDMA receiver utilizing soft feedback interference cancellation is analyzed. To be able to meet diverse QoS requirements, we introduce a power control scheme that takes into account multi-QoS objectives, as well as the impact of imperfect interference cancellation. Our results are general and provide a framework for capacity comparison for many proposed linear successive cancellation receiver models. Several receiver modifications are included, partial interference cancellation: when only part of the signal is canceled, and limited cancellation; when not every signal is canceled. We derive the minimum power solution, from which the resulting receiver capacity can be fully characterized. The results show that there are large gains in user capacity from interference cancellation when the Eb/Io requirements are high. However, regardless of the required targets, we find that the maximum capacity is always achieved through partial successive interference cancellation. It is also found that worse performance than conventional single-user detection can occur.

  • 53.
    Cai, Meng
    et al.
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Zhang, Xi
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Zhou, Ning
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Ben Slimane, Slimane
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    On the Capacity of CDMA with Linear Successive Interference Cancellation2003Inngår i: European Transactions on Telecommunications, New York: IEEE , 2003, s. 362-366Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Combined power control and interference cancellation in CDMA systems can be a very efficient resource management tool. While conventional power control tries to maintain equal received power or balanced SIR, Successive Interference Cancellation (SIC) in Multi-User Detection (MUD) relies more on the disparities between the powers of the different users. The combination can save more power into the system and thus a room for better capacity. This paper investigates the interaction between power control and linear SIC in a single rate CDMA system and its impact on the system capacity. The obtained results show that interference cancellation can improve the capacity of CDMA and relax power control requirements. The full integration of power control and SIC is shown to provide excellent resource management in CDMA systems. Limited cancellation can be a good solution for CDMA systems as it provides considerable capacity gain with reduced complexity. An upper bound on the system capacity as a function of the number of canceled signals is derived. Investigation of the optimum decoding order is also provided in this paper.

  • 54.
    Ferrer Coll, Javier
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Chilo, Jose
    Center for RF Measurement Technology, University of Gävle, Gävle, Sweden.
    Slimane, Ben
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Radio-Frequency Electromagnetic Characterization in Factory Automation Infrastructures2012Inngår i: IEEE transactions on electromagnetic compatibility (Print), ISSN 0018-9375, E-ISSN 1558-187X, Vol. 54, nr 3, s. 708-711Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

     In recent years, industrial wireless applications have emerged rapidly. The use of short-range radio communication systems in factories increases the flexibility in industrial processes by reducing the use of cables. However, the technological challenges involved in wireless communication in industrial environments are not trivial; they result in disadvantages with respect to reliability and security because of electromagnetic interferences. To gain an understanding of the performance limits of these wireless applications, knowing the characteristics of these environments is essential. In this approach, amplitude probability distribution (APD) and rms delay spread measurements have been used to perform electromagnetic site surveys in three factory automation infrastructures.

     

  • 55.
    Ferrer-Coll, Javier
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Radio Systems Laboratory (RS Lab). Center for RF Measurement Technology, University of Gävle.
    Simane, Ben
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Radio Systems Laboratory (RS Lab).
    Chilo, José
    Stenumgaard, Peter
    Detection and Suppression of Impulsive Noise in OFDM ReceiverManuskript (preprint) (Annet vitenskapelig)
  • 56.
    Ferrer-Coll, Javier
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Radio Systems Laboratory (RS Lab). University of Gävle, Sweden .
    Simane, Ben
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Radio Systems Laboratory (RS Lab).
    Chilo, José
    Stenumgaard, Peter
    Impulsive Noise Detec-tion in OFDM Systems with PAPR Reduction2014Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Impulsive noise is a major source of degradation in industrial communications. Orthogonal frequency-division multiplexing (OFDM) is an extended technique used in many industrial communications, however the performance of OFDM systems is reduced under an impulsive noise source. To increase the system performance, impulsive noise detection and suppression techniques can be designed in the communication system. OFDM has high levels of peak-to-average power ratio (PAPR), thus PAPR reduction techniques, such as selected mapping (SLM), are implemented in OFDM systems. This paper proposes an impulsive noise detection exploiting the statistical properties of the OFDM envelope when applying SLM. The proposed detection technique increases the probability of detection and improves the BER of the communication system compared to other impulsive detection techniques.

  • 57.
    Ferrer-Coll, Javier
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Slimane, Slimane Ben
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Chilo, J.
    Stenumgaard, P.
    Detection and Suppression of Impulsive Noise in OFDM Receiver2015Inngår i: Wireless personal communications, ISSN 0929-6212, E-ISSN 1572-834XArtikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In recent years, the use of wireless systems in industrial applications has experienced spectacular growth. Unfortunately, industrial environments often present impulsive noise which degrades the reliability of wireless systems. OFDM is an enhanced technology used in industrial communication to monitor the work and movement of employees using high quality video. However, OFDM is sensitive to high amplitude impulsive noise because the noise energy spreads among all OFDM sub-carriers. This paper proposes a receiver structure consisting of two stages: a detector stage combining Fisher’s Quadratic discriminant and Gaussian Hypothesis techniques, and a suppression stage optimized by setting well defined thresholds. The receiver structure has been tested by simulations and measurements providing an increment in the probability of detection and improving the system performance.

  • 58.
    Fodor, Gábor
    et al.
    Ericsson Research, Sweden.
    Roger, Sandra
    Rajatheva, Nandana
    Ben Slimane, Slimane
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Radio Systems Laboratory (RS Lab).
    Svensson, Tommy
    Popovski, Petar
    B. da Silva Jr., Jose Mairton
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik.
    Ali, Samad
    An Overview of Device-to-Device Communications Technology Components in METIS2016Inngår i: IEEE Access, E-ISSN 2169-3536, Vol. 4, s. 3288-3299Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    As the standardization of network-assisted deviceto-device (D2D) communications by the 3 rd Generation Partnership Project progresses, the research community has started to explore the technology potential of new advanced features that will largely impact the performance of 5G networks. For 5G, D2D is becoming an integrative term of emerging technologies that take advantage of the proximity of communicating entities in licensed and unlicensed spectra. The European 5G research project Mobile and Wireless Communication Enablers for the 2020 Information Society (METIS) has identified advanced D2D as a key enabler for a variety of 5G services, including cellular coverage extension, social proximity and communicating vehicles. In this paper, we review the METIS D2D technology components in three key areas of proximal communications – network-assisted multi-hop, full-duplex, and multi-antenna D2D communications – and argue that the advantages of properly combining cellular and ad hoc technologies help to meet the challenges of the information society beyond 2020.

  • 59.
    Gidlund, Mikael
    et al.
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Ben Slimane, Slimane
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Performance enhancement of wireless LANs through packet combining2001Inngår i: IEEE VTS 53rd Vehicular Technology Conference (VTS SPRING 2001), 2001, s. 1104-1108Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Wireless local area networks (WLANs) are faced with the presence of hidden terminals and the possibility of capture when operating in multipath radio channels. These phenomena complicate both their design and performance analysis. We consider a WLAN with CSMA/CA MAC protocol over mobile radio channels and evaluate its performance in terms of average throughput and average packet delay. In order to improve the system performance, we propose the use of different packet combining methods where the receiver keeps wrongly detected packets, combines them with their retransmitted versions and then makes a decision. Such a simple technique is well suited for wireless LANs since it provides a diversity gain to the system that can reduce interference problem (hidden terminal situation) and improve the capture effect. Simulation results show that both maximum ratio packet combining (MRPC) and hard decision can achieve a considerable gain in system throughput

  • 60. Gutiérrez, I.
    et al.
    Bader, F.
    Pijoan, J.
    Ben Slimane, Slimane
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster (Stängd 20120101), Kommunikationssystem, CoS (stängd 2012-01-01).
    Adaptive resource management for a MC-CDMA system with mixed QoS classes using a cross layer strategy2007Inngår i: 2007 IEEE 65th Vehicular Technology Conference, IEEE , 2007, s. 3036-3040Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Wireless communications are experiencing a great increasing demand, both user and bandwidth capacity. The efficiency in the resource management and usage will be a dramatically important issue since spectrum and power is a scarce resource, even more in the wireless environment. Under these circumstances, adaptive resource management will lead to high spectral efficiency rates and power saving algorithms. Previous works have focused on increasing the system capacity by means of complex power and rate adaptation techniques at the expense of unfair systems. The present proposal proposes a low complexity algorithm for adaptive resource allocation considering different quality of service classes in a Multicarrier-Code Division Multiple Access (MC-CDMA) system, which is considered according to several researches, as a promising air interface scheme for the Beyond 3G systems.

  • 61. Hamid, Mohamed
    et al.
    Ben Slimane, Slimane
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Van Moer, Wendy
    Bjorsell, Niclas
    Spectrum Sensing Challenges: Blind Sensing and Sensing Optimization2016Inngår i: IEEE Instrumentation & Measurement Magazine, ISSN 1094-6969, E-ISSN 1941-0123, Vol. 19, nr 2, s. 44-52Artikkel i tidsskrift (Fagfellevurdert)
  • 62.
    Hamid, Mohamed
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Björsell, Niclas
    Academy for Natural Science and Built Environment, University of Gävle.
    Slimane, Ben Slimane
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Downlink Throughput Driven Channel Access Framework for Cognitive LTE Femto-CellsManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    This paper proposes an optimized sensing based channel access framework for the LTE cognitive femto cells with an objective of maximizing femto-cells downlink throughput. Energy detection is used by the LTE cognitive femto cells to locate and thereafter utilize the free channels. Moreover, periodic sensing is adopted to detect any changes of the sensing outcomes. The developed channel access framework is based on an objective of maximization the femto-cell downlink throughput which varies with the macro-cell channel occupancy. Therefore, the LTE macro-cell occupancy statistics are empirically modelled using exponential distributions mixture. The LTE cognitive femto-cell downlink throughput is maximized by compromising the transmission efficiency, the explored spectrum opportunities and the interference from the macro-cell. An analytical solution for the optimal periodic sensing interval that maximizes the throughput is found and verified by simulations. The obtained results show that there is indeed a single periodic sensing interval value that maximizes the LTE cognitive femto-cell downlink throughput which changes with the change of the macro-cell channel occupancy. Yet, at a specific channel occupancy statistical parameters, our framework provides the optimal throughput. At the peak of the macro-cell traffic, our framework increased the femto-cell throughput by $\simeq 15\%$ compared to the senseless case. The impact of the available channels for opportunistic access is studied. The simulation results show that increasing the number of the available channels becomes less significant for more than three channels.

  • 63.
    Hamid, Mohamed
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Björsell, Niclas
    Academy for Natural Science and Built Environment, University of Gävle.
    Slimane, Ben Slimane
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Empirical Statistical Model for LTE Downlink Channel OccupancyManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    This paper develops an empirical statistical channel occupancy model for downlink long-term evolution (LTE) cellular systems. The model is based on statistical distributions mixtures for the holding times of the channels. Moreover, statistical distribution of the time when the channels are free is also considered. The data is obtained through an extensive measurement campaign performed in Stockholm, Sweden. Two types of mixtures are considered, namely, exponential and log-normal distributions to fit the measurement findings. The log-likelihood of both mixtures is used as a quantitative measure of the goodness of fit. Moreover, finding the optimal number of linearly combined distributions using the Akaike information criterion (AIC) is investigated. The results show that good fitting can be obtained by using either exponential or log-normal distributions mixture. Even though, the fitting is done for a representative case with a tempo-spatial consideration, the model is yet applicable in general for LTE and other cellular systems in a wider sense.

  • 64.
    Hamid, Mohamed
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Björsell, Niclas
    Academy for Natural Science and Built Environment, University of Gävle.
    Slimane, Ben Slimane
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Energy and Eigenvalue-Based Combined Fully-Blind Self-Adapted Spectrum Sensing Algorithm2015Inngår i: IEEE Transactions on Vehicular Technology, ISSN 0018-9545, E-ISSN 1939-9359, Vol. 65, nr 2, s. 630-642Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this paper, a comparison between energy and maximum-minimum eigenvalue detectors is performed. The comparison has been made concerning the sensing complexity and the sensing accuracy in terms of the receiver operating characteristics curves. The impact of the signal bandwidth compared to the observation bandwidth is studied for each detector. For the energy detector, the probability of detection increases monotonically with the increase of the signal bandwidth. For the maximum-minimum eigenvalue detector, an optimal value of the ratio between the signal bandwidth and the observation bandwidth is found to be $0.5$ when reasonable values of the system dimensionality are used. Based on the comparison findings, a combined two-stage detector is proposed. The combined detector performance is evaluated based on simulations and measurements. The combined detector achieves better sensing accuracy than the two individual detectors with a complexity lies in between the two individual complexities. The combined detector is fully-blind and self-adapted as the maximum-minimum eigenvalue detector estimates the noise and feeds it back to the energy detector. The performance of the noise estimation process is evaluated in terms of the normalized mean square error.

  • 65.
    Hamid, Mohamed
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Björsell, Niclas
    Academy for Natural Science and Built Environment, University of Gävle.
    Slimane, Ben Slimane
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Samples Covariance Matrix Eigenvalues Based Blind SNR Estimation2014Inngår i: Instrumentation and Measurement Technology Conference (I2MTC) Proceedings, 2014 IEEE International, 2014, s. 718-722Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper, a newly developed SNR estimation algorithm is presented. The new algorithm is based on the eigenvalues of the samples covariance matrix of the recieved signal. The presented algorithm is blind in the sense that both the noise and the signal power are unknown and estimated from the received samples. The Minimum Descriptive Length (MDL) criterion is used to split the signal and noise corresponding eigenvalues. The experimental results are judged using the Normalized Mean Square Error (NMSE) between the estimated and the actual SNRs. The results show that depending on the value of received vectors size, N, and the number of received vectors, L, the NMSE is changed and down to -55 dB NMSE can be achieved for the highest used values of  N and L.

  • 66.
    Hamid, Mohamed
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth. Department of Electronics, University of Gävle, Gävle, Sweden .
    Björsell, Niclas
    Academy for Natural Science and Built Environment, University of Gävle.
    Slimane, Ben Slimane
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Signal Bandwidth impact on Maximum-minimum Eigenvalue Detection2015Inngår i: IEEE Communications Letters, ISSN 1089-7798, E-ISSN 1558-2558, Vol. 19, nr 3, s. 395-398Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The impact of the signal bandwidth and observation bandwidth on the detection performance of the maximum-minimum eigenvalue detector is studied in this letter. The considered signals are the Gaussian signals. The optimum ratio between the signal and the observation bandwidth is analytically proven to be 0.5 when reasonable values of the system dimensionality are used. The analytical proof is verified by simulations.

  • 67.
    Hamid, Mohamed
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Radio Systems Laboratory (RS Lab). KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Björsell, Niclas
    University of Gävle, Sweden.
    Van Moer, Wendy
    Vrije Universiteit Brussel, ELEC department.
    Barbé, Kurt
    Vrije Universiteit Brussel, ELEC department.
    Slimane, Ben Slimane
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Radio Systems Laboratory (RS Lab). KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Blind spectrum sensing for cognitive radios using discriminant analysis: A novel approach2013Inngår i: IEEE Transactions on Instrumentation and Measurement, ISSN 0018-9456, E-ISSN 1557-9662, Vol. 62, nr 11, s. 2912-2921Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this paper, we present a new spectrum sensing technique for cognitive radios based on discriminant analysis called spectrum discriminator. The presented technique uses the knowledge of the noise uncertainty and a probabilistic validation to overcome the limitations of the discriminant analysis. A comparative study between the proposed technique and the maximum-minimum eigenvalue detection has been performed based on two performance metrics: the probability of false alarm and the probability of detection. The spectrum discriminator has been further developed to a peel-off technique where all primary users can be detected. The performance of the spectrum discriminator and the peel-off technique has been tested on simulations and experimentally verified. The comparative study is based on simulations as well as measurements.

  • 68.
    Hamid, Mohamed
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Slimane, Ben Slimane
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Van Moer, Wendy
    Vrije Universitat Brussels.
    Björsell, Niclas
    Academy for natural science and built environment, University of Gävle.
    Spectrum Sensing Challenges: Blind Sensing and Sensing Optimization2016Inngår i: IEEE Instrumentation & Measurement Magazine, ISSN 1094-6969, E-ISSN 1941-0123Artikkel i tidsskrift (Annet vitenskapelig)
  • 69.
    Hu, Ning
    et al.
    Tsinghua University.
    Chen, Xiang
    Tsinghua University.
    Zhong, Xiaofeng
    Tsinghua University.
    Ben Slimane, Slimane
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Li, Yunzhou
    Tsinghua University.
    Wang, Jing
    Tsinghua University.
    Energy-Efficient Relaying Strategy with Network Coding in Two-Way Parallel Channels2011Inngår i: ISRN Communications and Networking, ISSN 2090-4355, Vol. 2011Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We consider a two-way communication assisted by parallel regenerative decode-and-forward relays operating in orthogonal channels. In a system with limited channel state information at each source and relay node, an optimum distributed power allocation strategy is proposed to minimize the total transmit power, providing a target signal-to-noise ratio at each destination with a target outage probability. Moreover, combined with opportunistic relaying and network coding, a distributed decision mechanism is proposed for the relay node to decide whether to help the transmission or not. In this proposal, each source works out the transmit power and the decision threshold then broadcasts them. The selected relay compares the decision threshold with the channel gain of its weaker relay-to-destination link, then determines whether to forward the networkcoded data or not. Simulation results show the advantage of this strategy in terms of energy efficiency for a two-hop two-way communication scenario. The proposed strategy is very flexible as it can trade outage to power consumption and vice versa.

  • 70.
    Janssen, Gerard J. M.
    et al.
    Telecommunication and Traffic-Control Systems Group, Department of Information Technology and Systems, Delft University of Technology, 2600 GA Delft, The Netherlands.
    Ben Slimane, Slimane
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Antenna Diversity for a Narrow-band successive-Cancellation Multiuser Detector2004Inngår i: IEEE Transactions on Vehicular Technology, ISSN 0018-9545, E-ISSN 1939-9359, Vol. 53, nr 5, s. 1303-1315Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The performance of a successive-cancellation multiuser detector (SC-MUD) for narrow-band signals operating in the Rayleigh-fading channel is shown to deteriorate severely unless very large power margins at the receiver are maintained. To mitigate this deterioration, antenna diversity is applied and adapted to the SC-MUD. In each detection stage, the best signal for detection and the corresponding combining weights are determined jointly. Two criteria for selecting the best signal based on maximizing the signal-to-noise-plus-interference ratio and maximizing the minimum distance-to-noise ratio, respectively, are proposed and evaluated. For signal combining, zero forcing and minimum mean square error (mmse) combining are considered. The obtained results show that the SC-MUD with mmse combining performs close to maximum likelihood joint detection while keeping a much lower computational complexity when the number of users is less than the number of receive antennas. The effect of channel-estimation errors is investigated for orthogonal training sequences and shown to result in a minor degradation compared to perfect estimation.

  • 71.
    Janssen, Gerard J. M.
    et al.
    Telecommunication and Traffic-Control Systems Group, Department of Information Technology and Systems, Delft University of Technology, 2600 GA Delft, The Netherlands.
    Ben Slimane, Slimane
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    BER results for a narrowband multi-user receiver based on successive substraction for MPSK modulated signals2000Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A narrowband multiuser receiver based on successive signal detection and subtraction, is proposed. The Bit Error Rate (BER) performance for M-PSK modulated signals is evaluated and analytical approximations for the BER of the individual signals are presented and compared to the actual BER. The effect of inaccurately estimated signal parameters due to noise is analyzed. BER results are presented for synchronous signals for both Additive White Gaussian Noise (AWGN) and Rayleigh fading channels.

  • 72.
    Janssen, Gerard J. M.
    et al.
    Telecommunication and Traffic-Control Systems Group, Department of Information Technology and Systems, Delft University of Technology, 2600 GA Delft, The Netherlands.
    Ben Slimane, Slimane
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Symbol error probability analysis of a multiuser detector for M-PSK signals based on successive Cancellation2002Inngår i: IEEE Journal on Selected Areas in Communications, ISSN 0733-8716, E-ISSN 1558-0008, Vol. 20, nr 2, s. 330-338Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A narrow-band multiuser receiver based on successive signal detection and subtraction, is considered in this paper. The symbol error probability (SEP) for M-PSK modulated signals is evaluated and analytical approximations for the SEP of the individual signals are presented and compared with results obtained from simulations. For geometrically related signal amplitudes, a constant minimum distance can be guaranteed independent of the number of signals. The required amplitude ratio is shown to be related to and the number of co-channel signals. Optimizing the transmitted power for the different signals while ensuring the same SEP is then addressed and closed-form expressions of the signal amplitude ratios are derived. The effect of inaccurately estimated signal parameters due to noise is also analyzed. SEP results are presented for synchronous signals in an additive white Gaussian noise environment.

  • 73.
    Janssen, Gerard J. M.
    et al.
    Telecommunication and Traffic-Control Systems Group, Department of Information Technology and Systems, Delft University of Technology, 2600 GA Delft, The Netherlands.
    Ben Slimane, Slimane
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Symbol error probability of M-PSK multiuser detector using successive cancellation2000Inngår i: Electronics Letters, ISSN 0013-5194, E-ISSN 1350-911X, Vol. 36, nr 25, s. 2103-2105Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A narrowband multiuser receiver based on successive signal detection and subtraction is proposed. The symbol error probability (SEP) for M-PSK modulated signals is analysed and approximations for the SEP of the individual signals are presented and compared to results obtained from simulations for the AWGN channel.

  • 74.
    Janssen, G.J.M.
    et al.
    Delft University.
    Ben Slimane, Slimane
    Performance of a multiuser detector for M-PSK signals based on successive cancellation2001Inngår i: International Conference on Communications (ICC2001), 2001, s. 31-35Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A narrowband multiuser receiver based on successive signal detection and subtraction is proposed. The symbol error probability (SEP) for M-PSK modulated signals is evaluated and analytical approximations for the SEP of the individual signals are presented and compared to results obtained from simulations. The effect of inaccurately estimated signal parameters due to noise is analyzed. The SEP results are presented for synchronous signals for the additive white Gaussian noise (AWGN) channel. For geometrically related amplitudes the minimum required amplitude ratio is shown to be dependent on the modulation level M and the number of cochannel signals

  • 75. Jie, Xu
    et al.
    ShiChao, Li
    Ling, Qiu
    Slimane, Ben S.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    ChengWen, Yu
    Energy efficient downlink MIMO transmission with linear precoding2013Inngår i: Science China Information Sciences, ISSN 1674-733X, Vol. 56, nr 2, s. 022309-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Energy efficiency (EE) is becoming increasingly important for wireless cellular networks. This paper addresses EE optimization problems in downlink multiuser MIMO systems with linear precoding. Referring to different active transmit/receive antenna sets and transmission schemes as different modes, we propose a joint bandwidth/power optimization and mode switching scheme to maximize EE. With a specific mode, we prove that the optimal bandwidth and transmit power is either full transmit power or full bandwidth. After deriving the optimal bandwidth and transmit power, we further propose mode switching to select the mode with optimal EE. Since the optimal mode switching, i.e. exhaustive search, is too complex to implement, an alternative heuristic method is developed to decrease the complexity through reducing the search size and avoiding the EE calculation during each search. Through simulations, we demonstrate that the proposed methods can significantly improve EE and the performance is similar to the optimal exhaustive search.

  • 76.
    Khormuji, Majid N.
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Rizvi, Umar H.
    Janssen, Gerard J. M.
    Ben Slimane, Slimane
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Rotation optimization for MPSK/MQAM signal constellations over rayleigh fading channels2006Inngår i: 2006 10th IEEE Singapore International Conference on Communication Systems, Vols 1 and 2, 2006, s. 671-675Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The performance of uncoded phase-shift-keying (PSK) and quadrature amplitude modulation (QAM) schemes over fading channels can be improved by using coded modulation techniques. Improvement is due to the coding gain coupled with interleaving and depends on the complexity of the code. Recently, it was shown that constellation rotation coupled with interleaving can be used to improve the performance of QPSK modulation over block-fading single-input-single-output (SISO) wireless communication channels. This paper considers the use of such a scheme with higher order constellation sets such as 8PSK and 16QAM. A framework is then presented for the calculation of the optimum rotation angle for MPSK/MQAM schemes. A simple cost function based on the union bound of the symbol error probability (SEP) is defined. The optimum rotation angle is then found by minimizing the cost function using the gradient search algorithm. The obtained simulation results show considerable improvement over the conventional unrotated system.

  • 77.
    Lei, Zhu
    et al.
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Ben Slimane, Slimane
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    A multicarrier allocation (MCA) scheme for variable-rate 3Gwireless systems2000Inngår i: IEEE Communications Magazine, ISSN 0163-6804, E-ISSN 1558-1896, Vol. 38, nr 10, s. 86-91Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    High spectral efficiency and flexible data rate access are the main focus of future wireless networks. Multiple channel allocation schemes have the potential of achieving this goal. By assigning multiple slots and/or multiple carriers to one user, it is possible to provide a flexible data rate with quite low complexity. In this article we propose a simple allocation scheme where each user is assigned a fixed group of carriers. These carriers are adaptively used depending on the interference situation within the system. The system performance in terms of average throughput is investigated for two different types of allocation schemes: a fully centralized scheme and a distributed one that uses frequency diversity as a mean of improving the user link quality. The obtained results show that both schemes improve the system throughput over single carrier allocation without affecting the capacity of the system in terms of number of users per cell.

  • 78.
    Ligeti, Agnes
    et al.
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Ben Slimane, Slimane
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Local coverage probability estimation in single frequency networks2001Inngår i: Wireless personal communications, ISSN 0929-6212, E-ISSN 1572-834X, Vol. 18, nr 2, s. 105-128Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In OFDM based Single Frequency Networks (SFNs) such as Digital Audio Broadcasting (DAB) and Digital Video Broadcasting (DVB), the mobile receiver is provided by the same signal from several synchronous transmitters at the same carrier frequency. This transmitter diversity structure makes SFNs Very efficient in fading channels with an excellent spectrum saving, and very good power utilization over the service area. However, depending on the position of the mobile within the service area, these signals arrive with different delays causing possible echoes at the receiver. These echoes contribute to both the useful and the interfering parts of the signal. As the average received power in radio channels is a stochastic process, such contribution creates correlation between the different components of the Signal-to-Interference Ratio (SIR). In broadcasting practice, correlation was not taken into account when estimating the distribution of the SIR and the local coverage probability. This paper considers the effect of correlation on the estimation of the SIR and the coverage probability in OFDM based SFNs. Analyses are provided to show that in some situations the estimation error can be considerable when neglecting this correlation. To obtain a better estimation, the correlation coefficient between the total useful and total interfering parts of the received signal is first evaluated and then used as a correction factor in estimating the mean and standard deviation of the SIR. The obtained results show that such method can significantly reduce the estimation error of local coverage probability without increasing the computation complexity.

  • 79. Malik, J. S.
    et al.
    Ben Slimane, Slimane
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Radio Systems Laboratory (RS Lab).
    Hemani, Ahmed
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektroniksystem.
    Gohar, N. D.
    Improving performance of fading channel simulators by use of Uniformly distributed Random Numbers2011Inngår i: 2010 IEEE International Symposium on Signal Processing and Information Technology, 2011, s. 91-96Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Filter-based fading channel simulators universally use White Gaussian Noise (WGN) to generate complex tap coefficients. In this work, we will show that replacing WGN source by Uniform Random Number Generator (URNG) results in improved simulation speed in case of software simulator; and reduced area/power in case of hardware simulator. We will verify, both analytically and through extensive simulations, that use of URNG does not cause any degradation in important simulator performance parameters like statistical properties, spectral shape, level crossing rate and bit error rate. To validate our analysis, we have designed fading channel simulators both in software and hardware. We will show that use of URNG causes 6 percent improvement in simulation time in case of software simulator. Similarly, we will demonstrate that for a hardware simulator, we obtain an improvement of 30 and 40 percent in area and power consumption respectively.

  • 80.
    Malik, Jamshaid Sarwar
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektronik och Inbyggda System.
    Hemani, Ahmed
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektronik och Inbyggda System.
    Malik, J. N.
    Silmane, Ben
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Radio Systems Laboratory (RS Lab).
    Gohar, N. D.
    Revisiting central limit theorem: Accurate Gaussian random number generation in VLSI2015Inngår i: IEEE Transactions on Very Large Scale Integration (vlsi) Systems, ISSN 1063-8210, E-ISSN 1557-9999, Vol. 23, nr 5, s. 842-855, artikkel-id 6834810Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Gaussian random numbers (GRNs) generated by central limit theorem (CLT) suffer from errors due to deviation from ideal Gaussian behavior for any finite number of additions. In this paper, we will show that it is possible to compensate the error in CLT, thereby correcting the resultant probability density function, particularly in the tail regions. We will provide a detailed mathematical analysis to quantify the error in CLT. This provides a design space with more than four degrees of freedom to build a variety of GRN generators (GRNGs). A framework utilizes this design space to generate customized hardware architectures. We will demonstrate designs of five different architectures of GRNGs, which vary in terms of consumed memory, logic slices, and multipliers on field-programmable gate array. Similarly, depending upon application, these architectures exhibit statistical accuracy from low (4 σ ) to extremely high (12 σ). A comparison with previously published designs clearly indicate advantages of this methodology in terms of both consumed hardware resources and accuracy. We will also provide synthesis results of same designs in application-specific integrated circuit using 65-nm standard cell library. Finally, we will highlight some shortcomings associated with such architectures followed by their remedies.

  • 81.
    Malik, Jamshaid
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektroniksystem.
    Slimane, Ben
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Hemani, Ahmed
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektroniksystem.
    Gohar, N. D.
    NUST Pakistan.
    Impact of Interpolation Techniques on Statistical Properties and Speed of Fading Channel Simulators2010Inngår i: 6th International Conference on Wireless and Mobile Communications, ICWMC 2010, 2010, s. 117-124Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Interpolation filters are considered to be computationally intensive sections of fading channel simulators. They can be implemented by using linear interpolation or zero-padding followed by low-pass IIR or polyphase filtering. In this work, we will investigate how different interpolation techniques affect statistical properties and speed of the simulator.We will show that use of linear interpolation results in 3 to 6 times improvement in simulation speed while there is negligible degradation in desired statistical accuracy. We will validate this claim by designing a fading channel simulator that uses the above mentioned three interpolation techniques and observing their impact on its first order (probability density functions) and second order (correlation functions) statistical properties.We will also compare the impact of interpolation techniques on the level crossing rate (LCR) and bit error rate (BER) of the fading signal. Finally, we will emphasize our claim by using an advance multiple-tap channel model (gsmTUX6C1) with our simulator (using linear interpolation) and showing that its performance is comparable to corresponding Matlab model that uses polyphase interpolation. We will conclude this work with a recommendation to use linear interpolation for efficient and statistically correct fading channel simulators.

  • 82. Manssour, J.
    et al.
    Ahsin, Tafzeel ur Rehman
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Radio Systems Laboratory (RS Lab).
    Slimane, Ben
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Radio Systems Laboratory (RS Lab). KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Osseiran, A.
    Analysis and performance of network decoding strategies for cooperative network coding2013Inngår i: Physical Communication, ISSN 1874-4907, E-ISSN 1876-3219, Vol. 6, s. 48-61Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this work, we present two new low-complexity network decoding strategies for cooperative network coding in a multiple-access relay channel scenario. For these two strategies, Selection and Soft Combining and Majority Vote Network Decoding, along with the optimal joint network decoding, we derive expressions for bit error probability performance as a function of the signal-to-noise ratio (SNR) of the different Rayleigh fading links, and show the tightness of the derived bounds through simulation results. The two proposed schemes provide a similar bit error probability (BEP) performance compared to the optimal scheme, while having significantly lower complexity. Further, we study the effect of user pairing on the error performance by considering different SNRs on the user and relay links towards the destination. It is also shown that the error performance of the different schemes follows the same trend for a given user pairing strategy.

  • 83.
    Manssour, Jawad
    et al.
    Ericsson AB.
    Alyafawi, Islam
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Ben Slimane, Slimane
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Generalized Multiplicative Network Coding for the Broadcast Phase of Bidirectional Relaying2011Inngår i: 2011 IEEE GLOBECOM Workshop on Broadband Wireless Access: , 2011, s. 1336-1341Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A generalization of symbol-level multiplicative network coding is presented in this paper. The effects of non-constant amplitude modulation on the error probability of bidirectional relaying links are investigated analytically and through computer simulations. A constellation rearrangement is then presented to further enhance the performance. Simulation results show that the proposed method is able to alleviate the link asymmetry problem in bidirectional relaying and provide considerable throughput gains compared to equally simple network coding techniques.

  • 84.
    Manssour, Jawad
    et al.
    Ericsson AB.
    Osseiran, Afif
    Ericsson AB.
    Ben Slimane, Slimane
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    A Unicast Retransmission Scheme Based on Network Coding2012Inngår i: IEEE Transactions on Vehicular Technology, ISSN 0018-9545, E-ISSN 1939-9359, Vol. 61, nr 2, s. 871-876Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A novel scheme for data retransmission for wireless unicast communication is presented. The scheme is based on a transmitter and receiver structure and bit-level data processing using a combination of channel coding and network coding that allows retransmissions to contain the previously incorrectly received information and new information, both destined to the same receiver. Results show that, for the chosen forward error codes, up to 68.75% retransmission throughput gains are achieved compared to HARQ with Chase combining.

  • 85.
    Manssour, Jawad
    et al.
    Ericsson AB.
    Osseiran, Afif
    Ericsson AB.
    Ben Slimane, Slimane
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    High-Rate Redundant Space-Time Coding2010Inngår i: Journal of Electrical and Computer Engineering, ISSN 2090-0147, E-ISSN 2090-0155, Vol. 2010, s. 324138-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present a new space-time encoderbased on packet-level redundancy which can increase the space-time encoder rate beyond unity without compromising diversitygains. A complementary low-complexity decoding algorithmbased on maximum ratio combining and successive interferencecancelation is further proposed. A major merit of the decodingalgorithm is that it allows to adaptively tradeoff betweendiversity and multiplexing gains based on the estimated channelparameters at the receiver without requiring any channel stateinformation at the transmitter. System level simulation resultsgive insight into the advantages of the proposed scheme whencompared to its Alamouti and MIMO multiplexing based onsingle value decomposition counterparts.

  • 86.
    Manssour, Jawad
    et al.
    Ericsson AB.
    Osseiran, Afif
    Ericsson AB.
    Ben Slimane, Slimane
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Opportunistic relay selection for wireless network coding2009Inngår i: 2009 IEEE 9TH MALAYSIA INTERNATIONAL CONFERENCE ON COMMUNICATIONS (MICC), 2009, s. 102-106Konferansepaper (Fagfellevurdert)
  • 87.
    Manssour, Jawad
    et al.
    Ericsson AB.
    Osseiran, Afif
    Ericsson AB.
    Ben Slimane, Slimane
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Time Allocation in wireless network coding2009Inngår i: The 12th International Symposium on Wireless Personal Multimedia Communications, 2009Konferansepaper (Fagfellevurdert)
  • 88.
    Manssour, Jawad
    et al.
    Ericsson AB.
    Osseiran, Afif
    Ericsson AB.
    Ben Slimane, Slimane
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Wireless network coding in multi-cell networks: Analysis and Performance2008Inngår i: / [ed] Wysocki, BJ; Wysocki, TA, 2008, s. 160-165Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Network coding has recently attracted a lot of interest from the research community, mainly due to its simplicity of application and the large number of applications it can be suited for. Research in network coding started on wired networks, but the researchers soon came to realize that the inherent properties of the wireless medium render it a fertile ground for the application of network coding, and the resulting efforts mainly targeted bidirectional traffic scenarios. In this work, we focus on practical implementation issues for network coding when applied to uplink cellular traffic. We provide our own relaying scheme based on decode-and-forward relays and network coding, with a specially designed method of decoding at the receiver. We complement this method with user grouping in order to make better use of the application of network coding. We measure the SINR and capacity performances of our proposed scheme and compare them to the classical decode-and-forward algorithm in a system level simulator. We show that user grouping should complement a network coding solution in order to translate the decrease in the number of transmissions offered by network coding into capacity gains.

  • 89.
    Miao, Guowang
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Zander, Jens
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Sung, Ki Won
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Slimane, Slimane Ben
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Fundamentals of Mobile Data Networks2016Bok (Annet vitenskapelig)
  • 90.
    Osseiran, Afif
    et al.
    Ericsson Research, Ericsson AB, Stockholm, Sweden.
    Logothetis, Andrew
    Ericsson Research, Ericsson AB, Stockholm, Sweden.
    Ben Slimane, Slimane
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Distributed Relay Diversity Systems for OFDM-Based Networks2008Inngår i: International Journal of Communications, Network and System Sciences, ISSN 1913-3715, E-ISSN 1913-3723, Vol. 1, nr 3, s. 215-227Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this paper, distributed relay diversity systems are analyzed, modeled and evaluated in an Orthogonal Frequency Division Multiplexing (OFDM) based networks. The investigated distributed relay diversity schemes extend the ideas of a single hop transmit antenna schemes such as Cyclic Delay Diversity (CDD), Space Time Transmit Diversity (STTD), transmit Coherent Combining (CC) and Selection Diversity (SD) to distributed diversity systems. In contrast to the classical single hop system, the antennas in the distributed systems belongs to distributed relays instead of being co-located at the transmitter. The distributed relay diversity methods considered in this paper: Relay CDD (RCDD), Relay Alamouti (i.e.STTD), Relay CC (RCC) and Relay SD (RSD) are compared to the traditional 1-hop system. Analytical expressions for the received Signal to Interference Noise Ratio (SINR) are derived and used in a dynamic multi-cell multi-user simulator. Results show considerable SINR gains for both Round Robin and Max-SINR schedulers. The SINR gains translate into substantial cell throughput gains, up to 200%, compared to 1-hop systems. Despite its low complexity, the RCDD scheme has similar performance to that of other more sophisticated 2-hop schemes such as Relay Alamouti and Relay Coherent Combining. Marginally better results are observed for the Relay Selection Diversity scheme.

  • 91.
    Osseiran, Afif
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Logothetis, Andrew
    Ericsson Research, Ericsson AB, Stockholm, Sweden.
    Ben Slimane, Slimane
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Pilot Design Criteria for Single Carrier Frequency Domain Equalization on a Real-Time DSP-Based MIMO Test-Bed2006Inngår i: 2006 IEEE 64TH VEHICULAR TECHNOLOGY CONFERENCE, VOLS 1-6, IEEE , 2006, s. 261-264Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper, single carrier frequency domain equalization with space time transmit diversity was implemented and evaluated in real-time using a DSP-based wireless MIMO test-bed. A new pilot structure for joint carrier frequency offset (CFO) and channel estimation is proposed and evaluated, to address the adverse inter-symbol interference and the severe CFO due to hardware impairments. The channel estimation method is done in the frequency domain using a non-parametric interpolation method. The new pilot scheme results in significant reduction of the required overhead signalling compared to previous schemes.

  • 92.
    Osseiran, Afif
    et al.
    Ericsson Research, Ericsson AB, Stockholm, Sweden.
    Logothetis, Andrew
    Ericsson Research, Ericsson AB, Stockholm, Sweden.
    Ben Slimane, Slimane
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Larsson, Peter
    Ericsson Research, Stockholm, Sweden.
    Relay Cyclic Delay Diversity: Modeling & System Performance2007Inngår i: ICSPC: 2007 IEEE International Conference On Signal Processing And Communications, Vols 1-3, Proceedings, 2007, s. 25-28Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A cooperative communication scheme referred to as relay cyclic delay diversity (RCDD) is presented in this paper. The scheme is based on a set of distributed relay nodes (RNs) with each node associated with a certain cyclic shift in order to generate artificially multi-path diversity and equivalently frequency diversity. RCDD is an open loop scheme and the user terminal (UT) only needs to estimate an effective channel from all the RNs and not the channel from each RN. The effective channel induced by RCDD is frequency selective and can be exploited by a maximum signal to interference noise ratio (SINR) scheduler which improves substantially the system throughput. The SINR of the RCDD is derived analytically and the performance of the method is evaluated in a dynamic multi-cell multi-user simulator. The results show considerable SINR gains that translate into substantial cell throughput gains compared to 1-hop systems.

  • 93.
    Osseiran, Afif
    et al.
    Ericsson AB.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Ben Slimane, Slimane
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Network Coding in Wireless Communications2011Inngår i: Mobile and Wireless Communications for IMT-Advanced and Beyond / [ed] Afif Osseiran, Jose F. Monserrat, Werner Mohr, John Wiley & Sons, 2011, s. 181-205Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    This chapter deals with Network Coding (NC) in general and with its application to wireless communication in particular. A short overview of Network Coding in wired and wireless communications is given in section 8.1. Section 8.2, NC describes methods in uplink wireless communications. In section 8.3 the advantage of nonbinary network codes over binary network codes is shown in a multiuser co-operative communication and multirelay scenarios. The application of Network Coding (NC) to broadcast scenarios is then described. Finally, NC trends in wireless communications are given in section 8.5.

  • 94.
    Osseiran, Afif
    et al.
    Ericsson AB.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Ben Slimane, Slimane
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Skoglund, Mikael
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Manssour, Jawad
    Ericsson AB.
    Advances in wireless network coding for IMT-advanced & beyond2011Inngår i: 2011 2nd International Conference on Wireless Communication, Vehicular Technology, Information Theory and Aerospace and Electronic Systems Technology, Wireless VITAE 2011, 2011Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In a classical network, data streams originating from a source and intended to a desired destination are routed through intermediate nodes before reaching their final destination. By contrast, Network Coding (NC) manipulates at an intermediate node those data streams by combining the data from the streams before forwarding it to the destination. This paper describes the advances of NC in wireless communication for IMT-Advanced and beyond. A short overview of NC in wireless communications is given first. Afterward, the application of NC to broadcasting is described. Thereafter, NC methods in uplink wireless communications, such as User Grouping (UG) and Relay Selection (RS) are described. Further, the advantage of non-binary over binary network NC is shown in a multi-user multi-relay scenario. Finally the performance of NC is analyzed. In particular, in the uplink Multiple Access Relay Channel (MARC) scenario, the joint UG and RS methods lift the system capacity by 70%. The non-binary NC improves the SNR up to 4 dB. Finally the efficient broadcast method yields up to 22% overhead reduction compared to ARQ.

  • 95.
    Rizvi, Umar H.
    et al.
    Delft University of Technology.
    Janssen, Gerard J. M.
    tmeTelecommunication and Traffic-Control Systems Group, Deparnt of Information Technology and Systems, Delft University of Technology, 2600 GA Delft, The Netherlands.
    Ben Slimane, Slimane
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Combined multiple transmit antennas and multilevel modulation techniques2007Inngår i: 28th Symposium on Information Theory in the Benelux, 2007, s. 1-8Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The use of a unique bit-to-symbol mapping for each diversity branch (often referred to as constellation rearrangement) is known to provide good performance for higher level linear modulation techniques when used in conjunction with orthogonal transmit diversity (OTD) and automatic repeat request (ARQ) schemes. This paper investigates the performance of constellation rearrangement scheme when used in conjunction with multiple transmit antennas and space time block codes. A modified space-time block coding structure is presented that employs a different constellation mapping on each diversity branch. It is seen that, the use of different constellation mappings in the space time block coded systems provide a better performance as compared to the OTD systems while maintaining the same spectral efficiency.

  • 96.
    Sathananthan, K.
    et al.
    Telecommunication Program/SAT/Asian Institute of Technology, P.O. Box 4, Klong Luang, Pathumthani, 12120, Thailand.
    Rajatheva, R.M.A.P.
    Telecommunication Program/SAT/Asian Institute of Technology, P.O. Box 4, Klong Luang, Pathumthani, 12120, Thailand.
    Ben Slimane, Slimane
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Analysis of OFDM in the presence of frequency offset and a method to reduce performance degradation2000Inngår i: Global Telecommunications Conference, 2000. GLOBECOM '00. IEEE, New York: IEEE , 2000, s. 72-76Konferansepaper (Fagfellevurdert)
    Abstract [en]

    An orthogonal frequency division multiplexing (OFDM) system is sensitive to frequency errors, causing intercarrier interference (ICI) among subcarriers. We analyze the performance degradation of an OFDM system due to frequency offset errors and propose a new ICI cancellation method to reduce the effect of frequency offset errors. The main idea is to map each data symbol ak which is to be transmitted onto a pair of non-adjacent subcarriers k and (N-1-k), with weightings +1 and -1, other than to a single subcarrier. The carrier-to-interference ratio (CIR) of the proposed method is better than that of normal OFDM by an amount between 10 dB to 30 dB. This method has another advantage of the frequency diversity effect in the multipath fading channel. This study shows that the proposed method performs better than the previously described self-ICI cancellation method for a small value of frequency offset.

  • 97.
    Sathananthan, K.
    et al.
    Telecommunication Program/SAT/Asian Institute of Technology, P.O.Box 4, Klong Luang, Pathumthani, 12120, Thailand.
    Rajatheva, R.M.A.P.
    Telecommunication Program/SAT/Asian Institute of Technology, P.O.Box 4, Klong Luang, Pathumthani, 12120, Thailand.
    Ben Slimane, Slimane
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Cancellation Technique to Reduce Intercarrier Interference in OFDM2000Inngår i: Electronics Letters, ISSN 0013-5194, E-ISSN 1350-911X, Vol. 36, nr 25, s. 2078-2079Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Orthogonal frequency division multiplexing (OFDM) systems are sensitive to frequency errors, which cause intercarrier interference among subcarriers. A new cancellation method to reduce the effects of frequency offset errors is presented. The main feature is to map each data symbol ak which is to be transmitted onto a pair of non-adjacent subcarriers, with weightings +1 and -1, rather than to a single subcarrier. The carrier-to-interference ratio gain of the proposed method over normal OFDM varies between 10 to 30 dB. This method also offers a frequency diversity effect in a multipath fading channel.

  • 98.
    Shalmashi, Serveh
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Radio Systems Laboratory (RS Lab).
    Björnson, Emil
    KTH, Skolan för elektro- och systemteknik (EES), Signalbehandling. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre. SUPELEC, Alcatel-Lucent Chair on Flexible Radio.
    Slimane, Ben
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Radio Systems Laboratory (RS Lab).
    Debbah, Merouane
    SUPELEC, Alcatel-Lucent Chair on Flexible Radio.
    Closed-Form Optimality Characterization of Network-Assisted Device-to-Device Communications2014Inngår i: Proceedings of the IEEE Wireless Communications and Networking Conference (WCNC), 2014Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper considers the mode selection problem for network-assisted device-to-device (D2D) communications with multiple antennas at base station. We study transmission in both dedicated and shared frequency bands. Given the type of resources (i.e., dedicated or shared), the user equipment (UE) decides to transmit in the conventional cellular mode or directly to its corresponding receiver in D2D mode. We formulate this problem under two different objectives. The first problem is to maximize the quality-of-service (QoS) given a transmit power, and the second problem is to minimize the transmit power given a QoS requirement. We derive closed-form results for the optimal decision and show that the two problem formulations behave differently. Taking a geometrical approach, we study the area around the transmitter UE where the receiving UE should be to have D2D mode optimality, and how it is affected by the transmit power, QoS, and the number of base station antennas.

  • 99.
    Shalmashi, Serveh
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Radio Systems Laboratory (RS Lab). KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Miao, Guowang
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Radio Systems Laboratory (RS Lab).
    Han, Zhu
    University of Houston.
    Slimane, Ben
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Radio Systems Laboratory (RS Lab).
    Interference Constrained Device-to-Device Communications2014Inngår i: 2014 IEEE International Conference on Communications, ICC 2014, IEEE Computer Society, 2014, s. 5245-5250Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper considers a scenario in which multiple device-to-device (D2D) users can reuse the uplink resources of a cellular network to transmit directly to their corresponding receivers. The aggregated interference from the D2D users is limited by applying a threshold on the allowable interference in the base station. The problem is solved under two types of constraints, namely, the peak interference and average interference constraints. In the former, we assume that full channel state information (CSI) is available at the base station, and we optimize the allowable transmit power for the D2D users so that the number of coexisting D2D communications is maximized. We further define a quality-of-service constraint for the D2D users. In practice, however, it is difficult to have complete CSI at the base station as it imposes heavy signaling overhead. Therefore, in the latter scenario, we assume that no knowledge about the location of D2D users and their CSI are available at the base station. This approach does not impose any signaling overhead. Our results show that even with no CSI knowledge, we are able to improve the system performance in terms of throughput by allowing coexisting D2D communications while satisfying the cellular user's constraints.

  • 100.
    Shalmashi, Serveh
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Radio Systems Laboratory (RS Lab).
    Miao, Guowang
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Radio Systems Laboratory (RS Lab).
    Slimane, Ben
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Radio Systems Laboratory (RS Lab). KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Interference management for multiple device-to-device communications underlaying cellular networks2013Inngår i: 2013 IEEE 24th International Symposium on Personal Indoor and Mobile Radio Communications (PIMRC), IEEE conference proceedings, 2013, s. 223-227Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We study the problem of interference management for device-to-device (D2D) communications where multiple D2D users may coexist with one cellular user. The problem is to optimize the transmit power levels of D2D users to maximize the cell throughput while preserving the signal-to-noise-plus-interference ratio (SINR) performance for the cellular user. This is the so-called multi rate power control problem. We investigate the problem under two assumptions, the availability of the instantaneous or average channel state information (CSI) at the base station. In the first case, D2D transmit power levels adapt to fast fading, whereas in the second case, they only adapt to slow fading. In the latter assumption, the cellular user has a maximum outage probability requirement. With numerical results, we study the trade-off between the signaling overhead, that is frequent CSI feedbacks, and the overall system performance, that is the maximum achievable cell capacity, for D2D communications underlying cellular networks.

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