Change search
Refine search result
1 - 23 of 23
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Huu, Tung Pham
    et al.
    NUCE, Fac Informat Technol., VNM.
    Quach, Truong Xuan
    TNU Univ Informat & Commun Technol. VNM.
    Tran, Hung
    Malardalen Univ., SWE.
    Zepernick, Hans-Juergen
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Sibomana, Louis
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    On Proactive Attacks for Coping With Cooperative Attacks in Relay Networks2017In: 2017 23RD ASIA-PACIFIC CONFERENCE ON COMMUNICATIONS (APCC): BRIDGING THE METROPOLITAN AND THE REMOTE, 2017, p. 220-225Conference paper (Refereed)
    Abstract [en]

    Cooperative communications in which relays assist the transmission of signals from source to destination offer extended radio coverage and improved link reliable. However, transmitting signals with the help of a relay network may also open additional avenues for eavesdropper to overhear confidential information. Further, as jammers and eavesdroppers may cooperate to attack the relay network, offering secure communications becomes a challenging problem. To cope and reduce the effect of such cooperative attacks, we propose a proactive attack scheme in which the legitimate users generate jamming signals in an attempt to counteract such hostile cooperative attacks. In order to assess the security performance of the proactive attack scheme compared to a non-protection scheme, an analytical expression of the secrecy outage probability is derived. Numerical results for different system settings are provided showing that the proactive attack scheme can indeed significantly improve the security performance of the considered relay networks.

  • 2.
    Kabiri, Charles
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Sibomana, Louis
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Zepernick, Hans-Jürgen
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Symbol Error Probability and Effective Capacity of an Underlay CRN over alpha-mu Fading Channels2015In: 2015 9TH INTERNATIONAL CONFERENCE ON SIGNAL PROCESSING AND COMMUNICATION SYSTEMS (ICSPCS), IEEE Communications Society, 2015Conference paper (Refereed)
    Abstract [en]

    This paper analyses the performance of an underlay cognitive radio network (CRN) over alpha-mu fading channels in terms of symbol error probability (SEP) and effective capacity (EC). The alpha-mu distribution allows for a more general fading model with an increased level of generality compared to well-known models such as Nakagami-m and Rayleigh fading. The SEP and EC at the secondary user receiver are therefore evaluated for different fading parameters alpha and mu In the considered underlay CRN, the secondary user transmit power is subject to a peak interference power constraint in order to limit the interference to the primary user receiver. Given this setting, analytical expressions for the SEP and EC are derived for the general case of alpha-mu fading channels. Numerical results are provided to illustrate the performance of the considered underlay CRN on different fading channels.

  • 3.
    Kabiri, Charles
    et al.
    Blekinge Institute of Technology, School of Computing.
    Zepernick, Hans-Jürgen
    Blekinge Institute of Technology, School of Computing.
    Sibomana, Louis
    Blekinge Institute of Technology, School of Computing.
    Tran, Hung
    On the Performance of Cognitive Radio Networks with DF Relay Assistance Under Primary Outage Constraint Using SC and MRC2013Conference paper (Refereed)
    Abstract [en]

    In this paper, we analyze the performance of a cognitive radio network (CRN) that is assisted by a single relay. In particular, the secondary user (SU) transmitter (SU-Tx) and the secondary relay (SR) utilize the licensed frequency band of the primary user (PU). To protect the PU from harmful interference, the SU-Tx and SR must regulate their transmit power to satisfy the outage probability constraint of the PU. System performance in terms of outage probability is analyzed for selection combining (SC) and maximal ratio combining (MRC). Specifically, a power allocation policy and analytical expressions for the outage probability with SC and MRC are derived. Our results show that the upper bound of the outage probability corresponding to MRC is equal to the exact expression for the outage probability for SC.

  • 4.
    Louis, Sibomana
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Hans-Jürgen, Zepernick
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Ergodic Capacity of Multiuser Scheduling in Cognitive Radio Networks: Analysis and ComparisonArticle in journal (Refereed)
  • 5.
    Louis, Sibomana
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Hans-Jürgen, Zepernick
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Performance Analysis of Opportunistic Scheduling with HARQ for Cognitive Radio Networks2015In: IEEE Wireless Communications and Networking Conference, New Orleans, USA: IEEE Computer Society, 2015, p. 411-416-Conference paper (Refereed)
    Abstract [en]

    This paper analyzes the secondary network performance under the joint constraint of the primary user (PU) peak interference power and maximum transmit power limit of the secondary user (SU). In particular, N SU transmitters (SU-Txs) communicate with an SU receiver in the presence of a primary network with a PU transmitter and multiple PU receivers. Moreover, we exploit opportunistic scheduling where the SU-Tx with the best channel condition is scheduled for transmission. Analytical expressions of the outage probability and symbol error probability of the SU are obtained considering either perfect or statistical knowledge of the PU channel gains. Furthermore, we analyze the SU throughput for delay constrained applications with two hybrid automatic repeat request protocols, namely, repetition time diversity and incremental redundancy. Numerical results are provided to assess the effect of the number of SU-Txs and number of packet retransmissions on the secondary network performance. In addition, the impact of the primary network parameters on the secondary network is investigated.

  • 6.
    Louis, Sibomana
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Hans-Jürgen, Zepernick
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Hung, Tran
    On the Outage Capacity of an Underlay Cognitive Radio Network2015In: 2015 9TH INTERNATIONAL CONFERENCE ON SIGNAL PROCESSING AND COMMUNICATION SYSTEMS (ICSPCS), IEEE Press, 2015, p. 1-7-Conference paper (Refereed)
    Abstract [en]

    In this paper, we consider a point-to-multipoint underlay cognitive radio network under the joint constraint of the primary user peak interference power and maximum transmit power limit of the secondary user (SU). Analytical expressions for the secondary outage capacity are obtained based on exact as well as approximate expressions of the first and second moments of the channel capacity. Numerical results are provided to assess the effect of the number of SU receivers and a given SU outage probability. We also evaluate the impact of the primary network parameters on the secondary network performance.

  • 7.
    Louis, Sibomana
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Hans-Jürgen, Zepernick
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Hung, Tran
    Mälardalens högskola, SWE.
    Charles, Kabiri
    University of Rwanda, RWA.
    A Framework for Packet Delay Analysis of Point-to-Multipoint Underlay Cognitive Radio Networks2017In: IEEE Transactions on Mobile Computing, ISSN 1536-1233, E-ISSN 1558-0660, Vol. 16, no 9, p. 2408-2421Article in journal (Refereed)
    Abstract [en]

    This paper presents a queueing analytical framework for the performance evaluation of the secondary user (SU) packet transmission with service differentiation in a point-to-multipoint underlay cognitive radio network. The transmit power of the SU transmitter is subject to the joint outage constraint imposed by the primary user receivers (PU-Rxs) and the SU maximum transmit power limit. The analysis considers a queueing model for secondary traffic with multiple classes, and different types of arrival and service processes under a non-preemptive priority service discipline. The SU quality of service (QoS) is characterized by a packet timeout threshold and target bit error rate. Given these settings, analytical expressions of the packet timeout probability and average transmission time are derived for opportunistic and multicast scheduling. Moreover, expressions of the average packet waiting time in the queue and the total time in the system for each class of traffic are obtained. Numerical examples are provided to illustrate the secondary network performance with respect to various parameters such as number of PU-Rxs and SU receivers, SU packet arrival process, QoS requirements, and the impact of interference from the primary network to the secondary network.

  • 8.
    Sibomana, Louis
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Performance Analysis of Cognitive Radio Networks under Spectrum Sharing and Security Constraints2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The cognitive radio network (CRN) concept has been proposed as a solution to the growing demand and underutilization of the radio spectrum. To improve the radio spectrum utilization, CRN technology allows the coexistence of licensed and unlicensed systems over the same spectrum. In an underlay spectrum sharing system, secondary users (SUs) transmit simultaneously with the primary users (PUs) in the same frequency band given that the interference caused by the SU to the PU remains below a tolerable interference limit. Besides the transmission power limitation, a secondary network is subject to distinct channel impairments such as fading and interference from the primary transmissions. Also, CRNs face new security threats and challenges due to their unique cognitive characteristics.This thesis analyzes the performance of underlay CRNs and underlay cognitive relay networks under spectrum sharing constraints and security constraints. Distinct SU transmit power policies are obtained considering various interference constraints such as PU outage constraint or PU peak interference power constraint.

    The thesis is divided into an introduction and two research parts based on peer-reviewed publications. The introduction provides an overview of radio spectrum management, basic concepts of CRNs, and physical layer security. In the first research part, we study the performance of underlay CRNs with emphasis on a multiuser environment.In Part I-A, we consider a secondary network with delay-tolerant applications and analyze the ergodic capacity. Part I-B analyzes the secondary outage capacity which characterises the maximum data rate that can be achieved over a channel for a given outage probability. In Part I-C, we consider a secondary network with delay constrained applications, and derive expressions of the outage probability and delay-limited throughput. Part I-D presents a queueing model that provides an analytical tool to evaluate the secondary packet-level performance with multiple classes of traffic considering general interarrival and service time distributions. Analytical expressions of the SU average packet transmission time, waiting time in the queue, andtime spent in the system are provided.In the second research part, we analyze the physical layer security for underlay CRNs and underlay cognitive relay networks. Analytical expressions of the probability of non-zero secrecy capacity and secrecy outage probability are derived.Part II-A considers a single hop underlay CRN in the presence of multiple eavesdroppers (EAVs) and multiple SU-Rxs. In Part II-B, an underlay cognitive relay network in the presence of multiple secondary relays and multiple EAVs is studied.Numerical examples illustrate that it is possible to exploit the physical layer characteristics to achieve both security and quality of service in CRNs while satisfying spectrum sharing constraints.

    Download full text (pdf)
    fulltext
  • 9.
    Sibomana, Louis
    et al.
    Blekinge Institute of Technology, School of Computing.
    Hung, Tran
    Zepernick, Hans-Jürgen
    Blekinge Institute of Technology, School of Computing.
    Packet Timeout Probability for Uplink Spectrum Sharing2013Conference paper (Refereed)
    Abstract [en]

    In this paper, we consider an uplink spectrum sharing cognitive radio network (CRN). In particular, we assume that Nu. secondary user (SU) transmitters (SU-Txs) communicate with an SU receiver (SU-Rx) in the presence of a single primary link. Under the joint constraint of the primary user (PU) outage probability and SU-Tx maximum transmit power, the SU transmit power policy is obtained. Moreover, the SU-Tx with a minimum transmission time is scheduled for transmission. Accordingly, the cumulative distribution function (CDF) of packet transmission time is derived under independent but not necessary identically distributed (i.n.i.d.) Rayleigh fading channels to evaluate the packet timeout probability. Numerical examples are provided to investigate the impact of the SU transmit power policy, the interference from the PU transmitter (PU-Tx) to the SU-Rx, the number of SU-Tx, and the packet size on the secondary network performance. The results indicate that the packet transmission time can be minimized as the number of SU-Tx becomes large.

  • 10.
    Sibomana, Louis
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Tran, Hung
    Tran, Quang Anh
    Impact of secondary user communication on security communication of primary user2015In: Security and Communication Networks, ISSN 1939-0114, E-ISSN 1939-0122, Vol. 8, no 18, p. 4177-4190Article in journal (Refereed)
    Abstract [en]

    Cognitive radio network concept has been considered as a promising solution to improve the spectrum utilization. However, it may be vulnerable to security problems as the primary user (PU) and secondary user (SU) access the same resource. In this paper, we consider a system model where an eavesdropper (EAV) illegally listens to the PU communication in the presence of a SU transmitter (SU-Tx) communicating with a SU receiver (SU-Rx). The SU-Tx transmit power is subject to the peak transmit power constraint of the SU and outage probability constraint of the PU. Given this context, the effect of the interference from the SU-Tx to the EAV on the primary system security is investigated. In particular, analytical expressions of the probability of existence of non-zero secrecy capacity and secrecy outage probability of the PU are derived. Moreover, the performance analysis of the secondary network is examined where closed-form expressions of the symbol error probability and achievable rate are presented. Numerical examples are provided to evaluate the impact of the primary system parameters and channel conditions among users on the system performance of secondary and primary networks. Interestingly, our results reveal a fact that the security of the primary network strongly depends on the channel condition of the SU-Tx to the EAV link and the transmit power policy of the SU-Tx. Copyright (C) 2015 John Wiley & Sons, Ltd.

  • 11.
    Sibomana, Louis
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Tran, Hung
    Zepernick, Hans-Jürgen
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    On Physical Layer Security for Cognitive Radio Networks with Primary User Interference2015Conference paper (Refereed)
    Abstract [en]

    In this paper, we investigate the secondary network physical layer security under the outage constraint of the primary user (PU) receiver and interference from the PU transmitter to the secondary network. In particular, a secondary user (SU) transmitter sends confidential messages to trusted multiple SU receivers (SU-Rxs) in the presence of multiple eavesdroppers (EAVs). Further, we exploit multiuser diversity where the SU-Rx with best channel condition is scheduled for transmission. Then, analytical expressions of the probability of existence of non-zero secrecy capacity and secrecy outage probability are obtained. Analytical and simulation results are provided to evaluate the effect of the number of SU-Rxs and number of EAVs on the secondary system. Interestingly, the numerical results show that the interference from the primary network to the secondary network is an important parameter to improve the secondary network security.

  • 12.
    Sibomana, Louis
    et al.
    Blekinge Institute of Technology, School of Computing.
    Tran, Hung
    Blekinge Institute of Technology, School of Computing.
    Zepernick, Hans-Jürgen
    Blekinge Institute of Technology, School of Computing.
    Kabiri, Charles
    Blekinge Institute of Technology, School of Computing.
    On Non-zero Secrecy Capacity and Outage Probability of Cognitive Radio Networks2013Conference paper (Refereed)
    Abstract [en]

    In this paper, we consider a spectrum sharing cognitive radio network (CRN) in the presence of an eavesdropper (EAV) who illegally listens to the primary user (PU) communication. Under the PU outage and the secondary user (SU) peak transmit power constraints, the adaptive transmit power policy of the SU transmitter (SU-Tx) is obtained. Then, expressions for the probability of existence of a non-zero secrecy capacity of the primary network and the outage probability of the secondary network are derived. Numerical results are provided to investigate the impact of the SU-Tx peak transmit power, PU average transmit power and channel mean powers among users on the outage probability and probability of existence of a nonzero secrecy capacity. Our results illustrate that the probability of existence of a non-zero secrecy capacity strongly depends on the channel conditions among users and SU-Tx adaptive transmit power policy.

  • 13.
    Sibomana, Louis
    et al.
    Blekinge Institute of Technology, School of Computing.
    Zepernick, Hans-Jürgen
    Blekinge Institute of Technology, School of Computing.
    Cooperative ARQ for Spectrum Sharing Cognitive Relay Networks2013Conference paper (Other academic)
    Abstract [en]

    Current and future wireless networks are expected to provide high data rates and increased bandwidth utilization. Spectrum sharing cognitive radio networks have been proposed to increase the spectrum efficiency where a secondary user (SU) coexists with a primary user (PU) as long the interference from the SU to the PU receiver (PU-Rx) is properly controlled. Thus, the SU transmission is limited due to the interference power constraint. To overcome the secondary system coverage limitation, cognitive cooperative relaying has been considered to improve the secondary system capacity. In this work, we analyze a cooperative automatic repeat request (ARQ) cognitive relay network where an SU transmitter (SU-Tx) communicates with an SU receiver (SU-Rx) with the help of a single secondary relay (SR) in the presence of a single primary link. The channels are assumed to be independent Rayleigh fading and perfectly known. In order to protect the primary system against harmful interference from the secondary system, a peak interference power constraint that the PU can tolerate is considered. In addition, the SU-Tx and SR are also limited by their maximum transmit power constraints. In particular, we evaluate the outage probability of the secondary network for non-cooperative and cooperative ARQ (C-ARQ). To minimize the outage probability, the SR will retransmit the message to the SU-Rx if the SU-Tx to SU-Rx link is in outage. For delay limited applications, the message retransmission is bounded by the maximum number of retransmissions. The outage probability for C-ARQ at the SU-Rx depends on the probability of the SR of being able to decode the message. The numerical results indicate that the secondary network outage probability of the C-ARQ significantly outperforms the Non-C-ARQ. Moreover, the secondary network performance is degraded when the channel mean powers of the interference links increase.

  • 14.
    Sibomana, Louis
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Zepernick, Hans-Jürgen
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Hung, Tran
    Wireless Information and Power Transfer in an Underlay Cognitive Radio Network2014In: 2014 8TH INTERNATIONAL CONFERENCE ON SIGNAL PROCESSING AND COMMUNICATION SYSTEMS (ICSPCS), IEEE, 2014Conference paper (Refereed)
    Abstract [en]

    In this paper, we consider a secondary network with simultaneous wireless information and power transfer in a spectrum sharing scenario. In particular, a secondary user (SU) transmitter communicates with multiple SU receivers (SU-Rxs) under the peak interference power constraint of the primary user receiver and the SU maximum transmit power limit. We apply a channel quality-based threshold and exploit opportunistic scheduling. Specifically, an SU-Rx with best channel condition among a set of SU-Rxs satisfying the threshold is scheduled for data transmission. The remaining SU-Rxs with channel condition below the threshold, harvest the radio frequency energy. Analytical expressions of the SU ergodic capacity, symbol error rate, throughput, and energy harvesting are obtained. An optimal threshold satisfying a given target outage probability is determined. Numerical results are provided to investigate the impact of different parameters on the secondary network performance.

    Download full text (pdf)
    fulltext
  • 15.
    Sibomana, Louis
    et al.
    Blekinge Institute of Technology, School of Computing.
    Zepernick, Hans-Jürgen
    Blekinge Institute of Technology, School of Computing.
    Kabiri, Charles
    Blekinge Institute of Technology, School of Computing.
    Tran, Hung
    Outage Performance Analysis of Cognitive Relay Networks with BRS and MMRS2013Conference paper (Refereed)
    Abstract [en]

    In this paper, we consider a spectrum sharing system where a secondary user (SU) transmitter (SU-Tx) communicates with an SU receiver (SU-Rx) with the help of multiple secondary relays (SRs) in the presence of a single primary network link. In particular, the SU-Tx and SR are subject to their maximum transmit power limits and the timeout constraint of the primary user (PU). Moreover, we assume that the relay selection is based on either best relay selection (BRS) or max-max relay selection (MMRS). In BRS, a single relay having the best end-to-end channel condition among the SRs is selected for cooperation between the source and the destination. However, the selected relay may not experience the best source-relay channel and relay-destination channel at the same time. To overcome the limitation of selecting the same relay for both reception and transmission, MMRS uses the best relay of the SU-Tx→SR link for reception at the relay and the best relay of the SR→SURx link for transmission to the destination. Specifically, we compare the performance for BRS and MMRS in terms of the outage probability, and study the impact of the number of SRs, PU transmit power and different channel mean powers of interference links on the secondary network performance. Furthermore, based on the performance of the MMRS and assuming that automatic repeat request (ARQ) is implemented for packet retransmission, we investigate the outage probability for delay limited applications. The numerical results indicate that the MMRS outperforms BRS when more than one SRs are deployed. The secondary network outage probability is reduced when the number of SRs and the number of retransmissions become large. It is also shown that the interference from the PU has a significant impact on the secondary network performance.

  • 16.
    Sibomana, Louis
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Zepernick, Hans-Jürgen
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Tran, Hung
    Achievable Secrecy Capacity in an Underlay Cognitive Radio Network2014Conference paper (Refereed)
    Abstract [en]

    In this paper, we consider a spectrum sharing cognitive radio network where a secondary user (SU) transmitter (SU-Tx) communicates with multiple SU receivers (SU-Rxs). There exist multiple eavesdroppers (EAVs) who illegally listen to the secondary network communication. Further, the primary network consists of a primary user (PU) transmitter serving multiple PU receivers. In particular, the SU-Tx transmit power is subject to the joint constraint of PU outage and SU maximum transmit power limit. Moreover, we investigate the secondary network physical layer security in terms of average secrecy capacity for both cases of known and unknown channel information of the EAV at the SU-Tx. Numerical results are provided to evaluate the impact of the number of PU-Rxs, number of EAVs, number of SU-Rxs, and channel mean powers among users on the SU average secrecy capacity.

    Download full text (pdf)
    fulltext
  • 17.
    Sibomana, Louis
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Zepernick, Hans-Jürgen
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Tran, Hung
    On Physical Layer Security for Reactive DF Cognitive Relay Networks2014Conference paper (Refereed)
    Abstract [en]

    This paper analyzes the physical layer security for cognitive relay networks under the peak interference power constraint of the primary user receiver. In particular, a secondary user (SU) transmitter communicates with an SU receiver through the help of multiple secondary relays (SRs) using a decode-and- forward (DF) protocol. There exist multiple eavesdroppers (EAVs) who illegally listen to the secondary network communication. We consider a reactive DF scheme, and only the SRs that satisfy a decoding threshold participate in the relay selection. Analytical expressions of the probability of existence of secrecy capacity and secrecy outage probability are obtained. Numerical results are provided to evaluate the impact of the number of SRs, number of EAVs and channel mean powers on the secondary system security. We also investigate the effect of the interference from the primary network to the secondary network performance. Moreover, the performance of proactive DF is analyzed for the purpose of comparison.

    Download full text (pdf)
    fulltext
  • 18.
    Sibomana, Louis
    et al.
    Blekinge Institute of Technology, School of Computing.
    Zepernick, Hans-Jürgen
    Blekinge Institute of Technology, School of Computing.
    Tran, Hung
    Blekinge Institute of Technology, School of Computing.
    Kabiri, Charles
    Blekinge Institute of Technology, School of Computing.
    Packet transmission time for cognitive radio networks considering interference from primary user2013Conference paper (Refereed)
    Abstract [en]

    In this paper, we investigate a downlink model for underlay cognitive radio networks (CRNs). In particular, we assume that the secondary transmitter (SU-Tx) sends common packets to secondary receivers (SU-Rx) under the outage constraint of a single primary user (PU) and the peak transmit power constraint of the SU-Tx. All channels undergo Rayleigh fading. Given these settings, an adaptive transmit power policy for the SU-Tx is considered. Moreover, the cumulative distribution function (CDF) and probability density function (PDF) for packet transmission time are derived to analyze the timeout probability, the average packet transmission time and the average time a packet spends in the system for the SU-Rx having the best channel condition. Numerical results are provided to investigate the impact of the PU transmit power and channel mean powers on secondary network performance. The results show that when the number of SU-Rx becomes large, the timeout probability and the packet average time in the system decrease to a minimum.

  • 19.
    Sibomana, Louis
    et al.
    Blekinge Institute of Technology, School of Computing.
    Zepernick, Hans-Jürgen
    Blekinge Institute of Technology, School of Computing.
    Tran, Hung
    Blekinge Institute of Technology, School of Computing.
    Kabiri, Charles
    Blekinge Institute of Technology, School of Computing.
    Timeout Probability for Cognitive Radio Networks2012Conference paper (Other academic)
    Abstract [en]

    Cognitive radio networks (CRNs) promise solutions to increase the spectrum utilization in wireless systems. In underlay cognitive radio spectrum sharing, the non-licensed users referred to as secondary users (SUs) are allowed to transmit simultaneously over the same frequency of licensed users known as primary users (PUs) as long as the interference to the primary receiver (PU-Rx) caused by the secondary transmitter (SU-Tx) remains below a predefined threshold. In this work, we investigate a downlink model for CRN. In particular, we assume that the SU-Tx sends common packets to secondary receivers (SU-Rx) under the outage constraint of a single PU and the peak transmit power constraint of the SU-Tx. All channels undergo Rayleigh fading. Given these settings, an adaptive transmit power policy for the SU-Tx is obtained. Moreover, we derive the cumulative distribution function (CDF) for minimum packet transmission time to analyze the timeout probability for SU-Rx having the best channel condition. Numerical results are provided to investigate the impact of PU transmit power and channel mean power gain on secondary network performance. The secondary system performance does not only depend on the outage constraint imposed by the PU and the SU peak transmit power but also on the interference from PU-Tx to SU-Rx. By increasing the number of SU-Rx, the timeout probability decreases to a minimum value.

  • 20.
    Sibomana, Louis
    et al.
    Blekinge Institute of Technology, School of Computing.
    Zepernick, Hans-Jürgen
    Blekinge Institute of Technology, School of Computing.
    Tran, Hung
    Blekinge Institute of Technology, School of Computing.
    Ngoga, Said Rutabayiro
    Blekinge Institute of Technology, School of Computing.
    Packet Transmission for Multiservice Cognitive Radio Networks with Finite Buffer Capacity2013Conference paper (Refereed)
    Abstract [en]

    In this paper, we analyze the secondary network transmission given a packet timeout threshold and a target bit error rate (BER) in a downlink multiservice spectrum sharing cognitive radio network (CRN). Under the joint constraint of primary user (PU) outage probability and secondary user (SU) peak transmit power, the adaptive transmit power policy of the SU transmitter (SU-Tx) is obtained. The throughput is maximized by transmitting to the secondary receiver (SU-Rx) having the best channel condition. We maintain fairness with a minimum resource guarantee assigned to each packet of a class of service. Accordingly, the average packet transmission time is determined. In addition, employing an M/G/1/B queueing model, the packet blocking probability is given to develop expressions of the average throughput and packet loss probability for the secondary class of service. Moreover, the quality of experience (QoE) is evaluated based on the relationship between the packet loss probability and mean opinion score (MOS). The results show that the secondary network achieves the stable transmission quality and minimizes packet loss when the number of SU-Rx becomes large.

  • 21.
    Tran, Hung
    et al.
    Mälardalens högskola, SWE.
    Kaddoum, Georges
    Universite du Quebec a Montreal, CAN.
    Gagnon, Francois
    Universite du Quebec a Montreal, CAN.
    Sibomana, Louis
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Cognitive radio network with secrecy and interference constraints2017In: Physical Communication, ISSN 1874-4907, Vol. 22, p. 32-41Article in journal (Refereed)
    Abstract [en]

    In this paper, we investigate the physical-layer security of a secure communication in single-input multiple-output (SIMO) cognitive radio networks (CRNs) in the presence of two eavesdroppers. In particular, both primary user (PU) and secondary user (SU) share the same spectrum, but they face with different eavesdroppers who are equipped with multiple antennas. In order to protect the PU communication from the interference of the SU and the risks of eavesdropping, the SU must have a reasonable adaptive transmission power which is set on the basis of channel state information, interference and security constraints of the PU. Accordingly, an upper bound and lower bound for the SU transmission power are derived. Furthermore, a power allocation policy, which is calculated on the convex combination of the upper and lower bound of the SU transmission power, is proposed. On this basis, we investigate the impact of the PU transmission power and channel mean gains on the security and system performance of the SU. Closed-form expressions for the outage probability, probability of non-zero secrecy capacity, and secrecy outage probability are obtained. Interestingly, our results show that the strong channel mean gain of the PU transmitter to the PU's eavesdropper in the primary network can enhance the SU performance.

  • 22.
    Tran, Hung
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Zepernick, Hans-Jürgen
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Phan, Hoc
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Sibomana, Louis
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Performance Analysis of a Cognitive Radio Network with a Buffered Relay2015In: IEEE Transactions on Vehicular Technology, ISSN 0018-9545, E-ISSN 1939-9359, Vol. 64, no 2, p. 566-579Article in journal (Refereed)
    Abstract [en]

    In this paper, we analyze the packet transmission time in a cognitive cooperative radio network (CCRN) where a secondary transmitter (SU-Tx) sends packets to a secondary receiver (SU-Rx) through the help of a secondary relay (SR). In particular, we assume that the SU-Tx and SR are subject to the joint constraint of the timeout probability of the primary user (PU) and the peak transmit powers of the secondary users. On this basis, we investigate the impact of the transmit power of the PUs and channel mean powers on the packet transmission time of the CCRN. Utilizing the concept of timeout, adaptive transmit power allocation policies for the SU-Tx and SR are considered. More importantly, analytical expressions for the endto- end throughput, end-to-end packet transmission time, and stable condition for the SR operation are obtained. Our results indicate that the second hop of the considered CCRN is not a bottleneck if the channel mean powers of the interference links of the networks are small and the SR peak transmit power is set to a high value.

    Download full text (pdf)
    fulltext
  • 23.
    Tran, Hung
    et al.
    Mälardalen University, SWE.
    Zepernick, Hans-Jürgen
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Sibomana, Louis
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Performance of cognitive radio networks under interference constraints of multiple primary users2016In: 2016, 10th International Conference on Signal Processing and Communication Systems, ICSPCS 2016 - Proceedings, IEEE, 2016Conference paper (Refereed)
    Abstract [en]

    In this paper, we study the performance of point-to-point communication in spectrum sharing systems under the peak interference power constraint of multiple primary users. In particular, we assume that the channels undergo independent but not necessarily identically distributed Nakagami-m fading with integer values of fading severity parameter m. The cumulative distribution function and probability density function for the signal-to-noise ratio are derived. Based on these formulas, we obtain analytical expressions for the outage probability, the ergodic capacity, and the symbol error probability. Numerical results are also provided to investigate the impact of the peak interference power-to-noise ratio, the number of primary users, and fading parameters on the performance of the secondary network. © 2016 IEEE.

1 - 23 of 23
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf