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  • 1.
    Cho, Jeong-woo
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster (Stängd 20120101), Telekommunikationssystem, TSLab (stängd 2012-01-01).
    Chong, Song
    KAIST (Korea Advanced Institute of Science and Technology).
    Stabilized Max-Min Flow Control Using PID and PII2 Controllers2005Ingår i: IEICE transactions on communications, ISSN 0916-8516, E-ISSN 1745-1345, Vol. E88-B, nr 8, s. 3353-3364Artikel i tidskrift (Refereegranskat)
    Abstract [en]

     This paper describes an 'analytical framework for the weighted max-min flow control of elastic flows in packet networks using PID and PII2 controller when flows experience heterogeneous round-trip delays. Our algorithms are scalable in that routers do not need to store any per-flow information of each flow and they use simple first come first serve (FCFS) discipline, stable in that the stability is proven rigorously when there are flows with heterogeneous round-trip delays. We first suggest two closed-loop system models that approximate our flow control algorithms in continuous-time domain where the purpose of the first algorithm is to achieve the target queue length and that of the second is to achieve the target utilization. The slow convergence [1] of many rate-based flow control algorithms, which use queue lengths as input signals, can be resolved by the second algorithm. Based on these models, we find the conditions for controller gains that stabilize closed-loop systems when round-trip delays are equal and extend this result to the case of heterogeneous round-trip delays with the help of Zero exclusion theorem. We simulate our algorithms with optimal gain sets for various configurations including a multiple bottleneck network to verify the usefulness and extensibility of our algorithms.

  • 2. G, Fodor
    et al.
    A, Rácz
    S, Blaabjerg
    Simulative analysis of routing and link allocation strategies in ATM networks supporting ABR services1998Ingår i: IEICE transactions on communications, ISSN 0916-8516, E-ISSN 1745-1345, Vol. E81-B, nr 5, s. 985-994Artikel i tidskrift (Refereegranskat)
  • 3.
    Kim, Sumin
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Signalbehandling. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Kim, J.
    Adaptive sensing period based distributed medium access control for cognitive radio networks2014Ingår i: IEICE transactions on communications, ISSN 0916-8516, E-ISSN 1745-1345, Vol. E97B, nr 11, s. 2502-2511Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this paper, we propose distributed medium access control (MAC) protocols based on an adaptive sensing period adjustment scheme for low-cost multiple secondary users in interweave-type cognitive radio (CR) networks. The proposed MAC protocols adjust the sensing period of each secondary user based on both primary sensing and secondary data channels in distributed manner. Then, the secondary user with the shortest sensing period accesses the medium using request-to-send (RTS) and clear-to-send (CTS) message exchange. Three components affect the length of each user’s sensing period: sensing channel quality from the primary system, data channel quality to the secondary receiver, and collision probability among multiple secondary transmitters. We propose two sensing period adjustment (SPA) schemes to efficiently improve achievable rate considering the three components, which are logarithmic SPA (LSPA) and exponential SPA (ESPA). We evaluate the performance of the proposed schemes in terms of the achievable rate and other factors affecting it, such as collision probability, false alarm probability, and average sensing period.

  • 4. Olmos, JJ Vegas
    et al.
    Pang, Xiaodan
    RISE ACREO AB; Technical University of Denmark.
    Lebedev, Alexander
    Sales, M.
    Monroy, Idelfonso Tafur
    Wireless and wireline service convergence in next generation optical access networks-the FP7 WISCON project2014Ingår i: IEICE transactions on communications, ISSN 0916-8516, E-ISSN 1745-1345, Vol. 97, nr 8, s. 1537-1546Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The next generation of information technology demands both high capacity and mobility for applications such as high speed wireless access capable of supporting broadband services. The transport of wireless and wireline signals is converging into a common telecommunication infrastructure. In this paper, we will present the Marie Curie Framework Program 7 project "Wireless and wireline service convergence in next generation optical access networks" (WISCON), which focuses on the conception and study of novel architectures for wavelength-division-multiplexing (WDM) optical multi-modulation format radio-over-fiber (RoF) systems; this is a promising solution to implement broadband seamless wireless wireline access networks. This project successfully concluded in autumn 2013, and is being follow up by another Marie Curie project entitled "flexible edge nodes for dynamic optical interconnection of access and core networks" (FENDOI), which will be also briefly described.

  • 5. Olmos, JJ Vegas
    et al.
    Pang, Xiaodan
    RISE ACREO AB; Technical University of Denmark.
    Monroy, I Tafur
    E-and W-Band High-Capacity Hybrid Fiber-Wireless Links2014Ingår i: IEICE transactions on communications, ISSN 0916-8516, E-ISSN 1745-1345, Vol. 97, nr 7, s. 1290-1294Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this paper we summarize the work conducted in our group in the area of E- and W-band optical high-capacity fiber-wireless links. We present performance evaluations of E- and W-band mm-wave signal generation using photonic frequency upconversion employing both VCSELs and ECLs, along with transmission over different type of optical fibers and for a number of values for the wireless link distance. Hybrid wireless-optical links can be composed of mature and resilient technology available off-the-shelf, and provide functionalities that can add value to optical access networks, specifically in mobile backhaul/fronthaul applications, dense distributed antenna systems and fiber-over-radio scenarios.

  • 6. Shibata, Naotaka
    et al.
    Yamamoto, Koji
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Murata, Hidekazu
    Yoshida, Susumu
    Channel-Gain-Based Transmission Scheduling for Cooperative Relaying2010Ingår i: IEICE transactions on communications, ISSN 0916-8516, E-ISSN 1745-1345, Vol. E93B, nr 3, s. 776-779Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A cooperative relaying. system with transmission scheduling is investigated Cooperative relaying, is composed of multiple links because the source;ends the data to more than one receiver, and the destination receive; multiple data transmitted by more than one transmitter Therefore. tithe source can transmit the data when the channel gains of the links are high, it is not clear which channel gains should he high in order to achieve high spectral efficiency In the present letter. the spectral efficiency of a cooperative relay me system is theoretically derived under the assumption that the source transmits the data only when the channel gains of links are above certain threshold values Numerical results reveal that a high spectral efficiency can be achieved by assuring a high channel gain for the link with the highest average received power among links to the destination.

  • 7.
    Takeuchi, Keigo
    et al.
    University of Electro-Communications, Department of Communication Engineering and Informatics.
    Müller, Ralf R.
    Norwegian University of Science and Technology, Department of Electronics and Telecommunications.
    Vehkaperä, Mikko
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Bias-Based Training for Iterative Channel Estimation and Data Decoding in Fast Fading Channels2011Ingår i: IEICE transactions on communications, ISSN 0916-8516, E-ISSN 1745-1345, Vol. E94B, nr 7, s. 2161-2165Artikel i tidskrift (Refereegranskat)
  • 8. Teshima, Kunihiko
    et al.
    Yamamoto, Koji
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Murata, Hidekazu
    Yoshida, Susumu
    Capacity Analysis of Cooperative Relaying Networks with Adaptive Relaying Scheme Selection2009Ingår i: IEICE transactions on communications, ISSN 0916-8516, E-ISSN 1745-1345, Vol. E92B, nr 12, s. 3744-3752Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In the present paper, the performance of cooperative relaying networks with adaptive relaying scheme selection is analyzed. Cooperative relaying is a new technique to achieve spatial diversity gain by using neighboring stations. However, when multiple stations transmit simultaneously, the number of interference signals increases. Therefore, the introduction of cooperative relaying in radio communication systems does not always increase the network capacity due to the co-channel interference. Therefore, in order to achieve high spectral efficiency, it is necessary to select cooperative relaying or non-cooperative relaying adaptively. Assuming both centralized and decentralized adaptive controls, the spectrum efficiency is evaluated. The performance under decentralized control is evaluated using a game-theoretic approach. Simulation results show that the introduction of cooperative relaying with centralized control always increases the spectral efficiency. On the other hand, Simulation results also show that, when each source selects a relaying scheme independently and selfishly to maximize its own spectral efficiency, the introduction of the co-operative relaying may reduce the spectral efficiency due to the increase in the number of interference signals.

  • 9. Tsumura, Shigehiko
    et al.
    Vehkaperä, Mikko
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Li, Zexian
    Tujkovic, Djordje
    Juntti, Markku
    Department of Electrical and Information Engineering, University of Oulu.
    Performance evaluation of turbo and space-time turbo coded MC-CDMA downlink in single and multi-cell environments2004Ingår i: IEICE transactions on communications, ISSN 0916-8516, E-ISSN 1745-1345, Vol. E87B, nr 10, s. 3011-3020Artikel i tidskrift (Refereegranskat)
  • 10.
    Wosinska, Lena
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik, Fotonik. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Chen, Jiajia
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik, Fotonik. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Larsen, Claus Popp
    Fiber Access Networks: Reliability Analysis and Swedish Broadband Market2009Ingår i: IEICE transactions on communications, ISSN 0916-8516, E-ISSN 1745-1345, Vol. E92B, nr 10, s. 3006-3014Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Fiber access network architectures such as active optical networks (AONs) and passive optical networks (PONS) have been developed to support the growing bandwidth demand. Whereas particularly Swedish operators prefer AON, this may not be the case for operators in other countries. The choice depends on a combination of technical requirements, practical constraints, business models, and cost. Due to the increasing importance of reliable access to the network services, connection availability is becoming one of the most crucial issues for access networks. which should be reflected in the network owner's architecture decision. In many cases protection against failures is realized by adding backup resources. However, there is a trade off between the cost of protection and the level of service reliability since improving reliability performance by duplication of network resources (and capital expenditures CAPEX) may be too expensive. In this paper we present the evolution of fiber access networks and compare reliability performance in relation to investment and management cost for some representative cases. We consider both standard and novel architectures for deployment in both sparsely and densely populated areas. While some recent works focused on PON protection schemes with reduced CAPEX the current and future effort should be put on minimizing the operational expenditures (OPEX) during the access network lifetime.

  • 11.
    Zhang, Zhi
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Lu, Zhonghai
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektroniksystem. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Chen, Qiang
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Yan, Xiaolang
    Design and Optimization of a CDMA-based Multi-Reader Passive UHF RFID System for Dense Scenarios2012Ingår i: IEICE transactions on communications, ISSN 0916-8516, E-ISSN 1745-1345, Vol. E95B, nr 1, s. 206-216Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In dense passive radio frequency identification (RFID) systems, code division multiple access (CDMA) techniques can be used to alleviate severe collisions and thus enhance the system performance. However, conventional CDMA techniques are challenging to implement, especially for passive tags due to cost and power constraints. In this paper, we design a CDMA-based multi-reader passive ultra high frequency (UHF) RFID system in which a reader detects only the strongest tag signal and a tag uses Gold codes only on the preamble and the data bits of RN16 without increasing its clock frequency. We present a new communication procedure based on dynamic framed slotted ALOHA (DFSA). In order to optimize the system, we theoretically analyze the system performance in terms of slot capacity and identification rate, and formally show how the code length and the number of readers affect the identification rate. Furthermore, we propose an effective method for tag estimation and frame size adjustment, and validate it via simulations. Through an example, we demonstrate how the analysis-based technique can be used to optimize the system configurations with respect to the number of readers and the number and length of Gold codes.

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