J.-P.M.G. Linnartz

Philips, Eindhoven, North Brabant, Netherlands

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Publications (42)22.25 Total impact

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    J.-P.M.G. Linnartz
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    ABSTRACT: Rapid time variations of the mobile communication channel have a dramatic effect on the performance of multicarrier modulation. This paper models the Doppler spread and computes its effect on the bit error rate (BER) for multicarrier code division multiple access (MC-CDMA) transmission and compares it to orthogonal frequency division multiplexing (OFDM). Also, we evaluate the transmission capacity per subcarrier to quantify the potential of MC-CDMA and (coded-) OFDM. We focus on linear receivers, in particular those using the minimum mean-square error (MMSE) criterion. Our channel and system models allow the computation of analytical performance results. Simulations verify some commonly used, yet critical assumptions
    IEEE Transactions on Vehicular Technology 12/2001; · 2.06 Impact Factor
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    J.-P.M.G. Linnartz, A. Gorokhov
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    ABSTRACT: The paper proposes and analyses a new receiver structure to mitigate the effect of Doppler on the reception of OFDM signals. A discrete-frequency channel representation is developed for the link between the input of the transmit I-FFT and the output of the receive FFT. It is based on a Taylor expansion of the time variations of the received subcarrier amplitudes. The model realistically addresses the correlation of fading at neighboring subcarriers. We study a new type of receiver which estimates not only amplitudes but also derivatives of subcarriers amplitudes. An adaptive MMSE filter is proposed to cancel the intercarrier interference (ICI) resulting from Doppler. This results in a substantial improvement of the link performance
    Personal, Indoor and Mobile Radio Communications, 2000. PIMRC 2000. The 11th IEEE International Symposium on; 02/2000
  • J.-P.M.G. Linnartz
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    ABSTRACT: The RAKE receiver for direct sequence (DS) spread spectrum can separate energy received over multiple propagation paths with different time delays. Each finger in the RAKE sees signals with a specific time delay, but it also sees some unwanted residual crosstalk from signals over differently delayed paths. If bit transitions occur in delayed reflection, the crosstalk between two fingers in the RAKE detector is determined by two partial correlation functions, which exhibit substantially inferior properties than can be achieved for the full (or periodic) autocorrelation function. The aim of this paper is twofold: (1) to propose a new model to estimate the variance of partial correlations; (2) to show that cyclic prefixes improve the BER experienced when DS is transmitted over a dispersive multipath channel
    Vehicular Technology Conference, 1999. VTC 1999 - Fall. IEEE VTS 50th; 02/1999
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    T. Tank, J.-P.M.G. Linnartz
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    ABSTRACT: Vehicle-to-vehicle radio links suffer from multipath fading and interference from other vehicles. We discuss the impact of these effects on communication networks supporting an intelligent transportation system (ITS), in particular, automated vehicle control systems (AVCSs). A statistical model for this channel is considered, and the performance of the network involving many links is evaluated. We compare the performance of time division multiple access (TDMA), direct-sequence code division multiple access (DS-CDMA), and frequency hopping with TDMA in this environment. The reliability of the radio link is investigated by specifying the radio spectrum occupation for a given required reliability of the radio link
    IEEE Transactions on Vehicular Technology 06/1997; · 2.06 Impact Factor
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    J.-P.M.G. Linnartz
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    ABSTRACT: In a wireless network with path loss and fading channels, receiver capture is known to substantially enhance the performance of the slotted ALOHA random access protocol. The efficiency of narrowband slotted ALOHA radio networks can be enhanced further by using sector antennas, each receiving signals from a particular segment of the network area. This paper investigates the effect of realistic, i.e., partially overlapping antenna patterns and the resulting correlation of received power levels at different receiver branches. A method is derived for computing the joint throughput from two base station receivers with overlapping antennas patterns. The a posteriori information provided by the event of one message capturing one antenna is used to find conditional probabilities of capturing the other antennas as well. The paper shows that any overlap in the antenna patterns decreases the throughput, but transmissions from the overlapping area may face a larger probability of capture than signals from directions in which one antenna has maximum gain
    IEEE Transactions on Communications 11/1996; · 1.75 Impact Factor
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    C. van den Broek, J.-P.M.G. Linnartz
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    ABSTRACT: The paper introduces a new protocol for wireless cellular networks by combining a time reservation scheme with a dynamic space reservation scheme. The proposed new protocol, known as the space and time reservation multiple access (STRMA) protocol, does not use a fixed reuse pattern but allows a dynamic reservation of bandwidth in both time and space. The performance of this protocol found by simulation is compared with the performance of a cellular network that uses PRMA with a fixed frequency reuse pattern. It is found that for homogenous traffic STRMA offers improved performance over a wide range of traffic loads. For inhomogeneous traffic the improvement is even more pronounced
    Personal, Indoor and Mobile Radio Communications, 1995. PIMRC'95. 'Wireless: Merging onto the Information Superhighway'., Sixth IEEE International Symposium on; 10/1995
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    S.P. Fedortsov, J.P.M.G. Linnartz
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    ABSTRACT: We address the transmission of data packets from base stations to mobile terminals in a one-dimensional cellular network. The probability that a data packet successfully arrives at the destined mobile terminal highly depends on the activity of nearby co-channel base stations. Motivated by favorable results from earlier studies we consider a network in which all base stations use the same radio channel. Packets lost because of mutual interference are retransmitted with a random backoff mechanism. Recursive arguments are applied for the calculation of the mean time necessary for a base station to deliver the packet, provided that in an initial state all stations have packets to transmit. The average delivery time, maximized over all base station locations, is also analyzed. The relations obtained give some further insight into the behavior of a (highway) cellular data network
    Personal, Indoor and Mobile Radio Communications, 1995. PIMRC'95. 'Wireless: Merging onto the Information Superhighway'., Sixth IEEE International Symposium on; 10/1995
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    J.-P.M.G. Linnartz
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    ABSTRACT: This paper proposes a radio architecture that offers two-way transmission services essential to intelligent vehicle highway systems (IVHS) using only a single (30 kHz) radio channel. Within this bandwidth multiple communication services can be supported, including datacasting, packet switched transmission to and from vehicles, collection of traffic data from probe vehicles and transmission of emergency messages. The design is based on theoretical investigations reported at PIMRC '93 and VTC '94 on packet-switched downlink transmissions and ALOHA random access for traffic reports from probe vehicles, respectively. These analyses revealed that contiguous frequency reuse gives optimum packet delay and highest spectrum efficiency. New results are included for datacasting messages to groups of vehicles
    Personal, Indoor and Mobile Radio Communications, 1994. Wireless Networks - Catching the Mobile Future., 5th IEEE International Symposium on; 10/1994
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    R.F. Diesta, J.-P.M.G. Linnartz
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    ABSTRACT: The spectrum efficiency of cellular radio data networks is maximized by increasing the cell throughput and decreasing the cluster sizes. However, smaller cluster sizes lead to higher cochannel interference and hence lower throughput. A multiple access and collision resolution scheme that accounts for the spatial aspects of cochannel interference is introduced and analyzed for roadside base station to vehicle packet communications in intelligent vehicle highway systems (IVHS). In a wireless network with base stations having full knowledge of neighboring station activity, cochannel interference and destructive collisions are diminished by using discontinuous transmissions and coordination: a base station is silenced (or power-controlled) by a neighboring station in order to improve the latter's chance of successful transmission and decrease retransmission attempts. Interaction among base stations makes efficient use of channel resources for both low- and high-intensity traffic
    Personal, Indoor and Mobile Radio Communications, 1994. Wireless Networks - Catching the Mobile Future., 5th IEEE International Symposium on; 10/1994
  • Y. Bar-Ness, J.-P. Linnartz, Xiangqun Liu
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    ABSTRACT: Multi-carrier (MC) multi-user CDMA is a new transmission method in which every user bit is sent simultaneously over multiple subcarriers (or multiple tones), each of which has a time-constant 0 or π phase offset. The offsets corresponding to each user form a unique code signature sequence, orthogonal to those of any other user, or pseudo orthogonal as with Gold codes or Kessami code sequences. We address a moderately dispersive channel in which each user-subcarrier channel has a different random amplitude and phase. We estimate the performance of a receiver matched to such a multicarrier, multi-user scheme. Then we implement a decorrelating interference canceler at the output and examine its effect on performance
    Personal, Indoor and Mobile Radio Communications, 1994. Wireless Networks - Catching the Mobile Future., 5th IEEE International Symposium on; 10/1994
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    R.F. Diesta, J.-P.M.G. Linnartz
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    ABSTRACT: This paper reviews progress in developing a mathematical framework to evaluate the performance of mobile radio links. It takes into account multi-ray multipath fading with Rician or Nakagami probability density, lognormal shadowing and path loss of wanted and interfering transmitters, additive white Gaussian noise, man-made burst noise and discontinuous transmission. The method uses Laplace transforms of the PDF of the power of each interfering signal. This method is computationally efficient and allows inclusion of a wide range of link aspects. We also show that, in contrast to common belief, it is not realistic to approximate the Rician fading of the wanted signal by a Nakagami model. New results are given for microcells along highways
    Personal, Indoor and Mobile Radio Communications, 1994. Wireless Networks - Catching the Mobile Future., 5th IEEE International Symposium on; 10/1994
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    N. Yee, J.-P. Linnartz
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    ABSTRACT: Analyzes the application of Wiener filtering to the detection of multi-carrier code division multiple access (MC-CDMA) signals. Simulation results are included to test the validity and accuracy of the analytical results
    Personal, Indoor and Mobile Radio Communications, 1994. Wireless Networks - Catching the Mobile Future., 5th IEEE International Symposium on; 10/1994
  • M.A. Couture, J.-P.M.G. Linnartz
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    ABSTRACT: The paper developed a refined model for DS spread spectrum transmission over a Rician fading channel. A prevalent model in previous papers has been to group all signals received other than the dominant LOS path as interference. A new approach is taken, whereby some components of the multipath are included in the desired signal. An expression for the local-mean BER is derived from this model, and an analysis of BER as a function of the number of users is performed
    Personal, Indoor and Mobile Radio Communications, 1994. Wireless Networks - Catching the Mobile Future., 5th IEEE International Symposium on; 10/1994
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    N.D. Vvdenskaya, J.-P.M.G. Linnartz
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    ABSTRACT: This paper evaluates the performance of a packet radio network employing code division multiple access and a stack algorithm to resolve message collisions. We investigate the effects of bandspreading assuming a fixed total system bandwidth. Although bandspreading with perfectly orthogonal signals enhances system capacity, it does not resolve the instability of ALOHA random access unless special measures are taken to control retransmission traffic. Using a stack algorithm, at small traffic loads the packet delay is minimized if no spreading is applied. At large traffic loads, perfect CDMA enhances performance, but for imperfect signal separation at the receiver, advantages of CDMA are lost. The capacity of the stack algorithm addressed here can be enhanced from 0.32 to at least 0.40 if a large spreading factor with perfect signal separation is employed
    Personal, Indoor and Mobile Radio Communications, 1994. Wireless Networks - Catching the Mobile Future., 5th IEEE International Symposium on; 10/1994
  • J.P.M.G. Linnartz, N.D. Vvdenskaya
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    ABSTRACT: The authors address the effect of code division multiple access (CDMA) on the performance of wireless packet-switched networks. Although CDMA can enhance throughput, the delay at small traffic loads suffers from bandspreading. For imperfect signal separation at the receiver, performance benefits from CDMA may be lost. The capacity of the particular stack algorithm addressed for collision resolution can be enhanced from 0.32 to ~0.40 if a 10 dB spreading gain with perfect signal separation is employed
    Electronics Letters 10/1994; · 1.04 Impact Factor
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    Hwa Jong Kim, J.-P. Linnartz
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    ABSTRACT: A new cellular communication architecture, called a `virtual cellular network' (VCN) is proposed and its performance is investigated in terms of probability of capture, throughput and delay. A VCN does not use a conventional cellular frequency reuse concept. In a VCN, each terminal sends packets using the entire system bandwidth while any nearby port can pick up the signal. Then, the ports relay the packets to the port server (PS) over a fixed (wired) network. This simplifies the functions of a port, and the placement of ports will be easier than that in a conventional cellular network. Both the present analysis and simulation show that despite its simplicity this network has a larger user capacity than conventional cellular reuse patterns
    Vehicular Technology Conference, 1994 IEEE 44th; 07/1994
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    N. Yee, J.-P. Linnartz
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    ABSTRACT: In this paper, a novel digital modulation technique called Multi-Carrier Code Division Multiple Access (MC-CDMA) is analyzed. With MC-CDMA, each data symbol is transmitted at multiple subcarriers with each subcarrier modulated by “1” or “-1” based on a spreading code. Analytical results are presented on the performance of this modulation/multiple access scheme in the downlink of an indoor wireless Rician fading channel. The performance of a controlled equalization technique that attempts to restore the orthogonality between users is evaluated
    Vehicular Technology Conference, 1994 IEEE 44th; 07/1994
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    R.F. Diesta, C.O.U. Eleazu, J.-P.M.G. Linnartz
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    ABSTRACT: Optimum frequency reuse patterns for roadside base station to vehicle communications in intelligent vehicle/highway systems (IVHS) are determined based on optimal delay/throughput and packet erasure rates for BPSK transmission over narrowband dispersive Rician channel with ISI and (Rayleigh-faded) co-channel interference. For fixed cluster size and fixed total system bandwidth, a reuse pattern of 2 for continuously transmitting (hence interfering) base stations gives minimum average delay and maximum spectrum efficiency: this is a denser pattern than suggested for highway cellular telephony networks. Spectrum efficiency is enhanced by using a dynamic cluster size which depends on the distance from the base station, taking advantage of the IVHS environment where vehicle position may be known
    Vehicular Technology Conference, 1994 IEEE 44th; 07/1994
  • J.-P.M.G. Linnartz, M. Westerman
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    ABSTRACT: The lack of proficient real time traffic monitoring systems is one of the major bottlenecks of Advanced Traveller Information Systems (ATIS) and Advanced Traffic Management Systems (ATMS). The authors describe and analyze the performance of a method for collecting real-time traffic data from probe vehicles automatically sending traffic reports to one or more base stations, connected to a traffic center by a wired communications network. The results reveal that random access (ALOHA) transmission of traffic reports is a (spectrum) efficient, inexpensive and flexible method for collecting road traffic data and that this approach can provide reliable traffic monitoring. Not only highly accurate real time link travel times can be estimated, but also Automatic Incident Detection (AID) can be performed
    Vehicular Technology Conference, 1994 IEEE 44th; 07/1994
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    T. Tank, N. Yee, J.-P. Linnartz
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    ABSTRACT: Vehicle-to-vehicle radio links suffer from power variations, multipath fading and associated Doppler spreading in frequency, as well as interference from other vehicles. These effects are investigated in the context of an automated vehicle control systems (AVCS) employing vehicle platoons. A statistical model for the channel is considered and the performance of the network involving many links is evaluated. We compare the performance of time division multiple access (TDMA), direct sequence code division multiple access (DS-CDMA), and multi-carrier code division multiple access (MC-CDMA). Reliability of the radio link is investigated by specifying the radio spectrum occupation for a given required reliability of the radio link
    Vehicular Technology Conference, 1994 IEEE 44th; 07/1994

Publication Stats

682 Citations
22.25 Total Impact Points

Institutions

  • 1999–2001
    • Philips
      • Philips Research
      Eindhoven, North Brabant, Netherlands
  • 1992–1997
    • University of California, Berkeley
      • Department of Electrical Engineering and Computer Sciences
      Berkeley, MO, United States
  • 1988–1995
    • Delft University of Technology
      Delft, South Holland, Netherlands
  • 1994
    • The Institute for Information Transmission Problems
      Moskva, Moscow, Russia
    • Kangwon National University
      • Department of Electronics Engineering
      Kang-neung, Gangwon, South Korea