M. Heskamp

Universiteit Twente, Enschede, Overijssel, Netherlands

Are you M. Heskamp?

Claim your profile

Publications (14)5.15 Total impact

  • Source
    M. Heskamp, C.H. Slump
    [Show abstract] [Hide abstract]
    ABSTRACT: In this paper we propose a combined signaling and spectrum sensing scheme for cognitive radio that can detect inband primary users while the networks own signal is active. The signaling scheme uses OFDM with phase shift keying modulated sub-carriers, and the detection scheme measures the deviation of each sub-carrier from a circular shape.
    Global Telecommunications Conference, 2009. GLOBECOM 2009. IEEE; 01/2010
  • M. Heskamp, C.H. Slump
    [Show abstract] [Hide abstract]
    ABSTRACT: An ideal cognitive radio must be able to detect primary user signals under unfavorable conditions. Especially when the hidden node problem occurs, a cognitive radio is required to detect the presence of signals under the noise floor. This paper addresses the question to what extent sub-noise detection is practically usable in a cognitive radio. Three methods based on cross-correlation are analyzed and compared.
    Communications, 2009. ICC '09. IEEE International Conference on; 07/2009
  • [Show abstract] [Hide abstract]
    ABSTRACT: This book gives comprehensive and balanced coverage of the principles of cognitive radio communications, cognitive networks, and details of their implementation, including the latest developments in the standards and spectrum policy. Case studies, end-of-chapter questions, and descriptions of various platforms and test beds, together with sample code, give hands-on knowledge of how cognitive radio systems can be implemented in practice. Extensive treatment is given to several standards, including IEEE 802.22 for TV White Spaces and IEEE SCC41.
    IEEE Journal of Solid-State Circuits 01/2009; · 3.06 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A novel low-mast low-power terrestrial digital audio broadcasting (T-DAB) single frequency network topology is described and evaluated in this paper. For this purpose, a pilot network (band III and L-band) was constructed in Amsterdam, the Netherlands. The performance of the band III pilot network (channel 12B) is compared with the existing traditional high-power high-mast T-DAB network (channel 12C) of the public service broadcaster. An important goal is to investigate whether the pilot network can co-exist with an existing traditional T-DAB network. The field trial shows that a gap filler can effectively neutralize the adjacent channel interference of the pilot network on the existing T-DAB network. Moreover, the L-band pilot network is compared with both band III networks by assessing the indoor coverage of every network. For estimation of the indoor coverage, 34 objects were investigated. Both the indoor penetration loss for band III and L-band was determined for each object. Indoor coverage in a region is reached if 95% of the buildings or more have indoor coverage. Using this definition, the loss for band III is 21.6 dB and for L-band 24.6 dB. As a result we consider the indoor penetration loss values reported in literature as too optimistic. Also other parameters of the pilot network were measured, such as the frequency re-use distance.
    IEEE Transactions on Broadcasting 10/2008; · 2.09 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This technical report contains the results of the research conducted within the Freeband-AAF project. The research relates to the Network-, Link- and Physical layers of Cognitive Radio
    Journal of Object Technology - JOT. 01/2008;
  • M. Heskamp, C. H. Slump
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper describes a method for interpolating power density spectrum measurements in order to find the center frequency and signal features of unknown radio signals. Signal features are retrieved by applying a non linear operation to the signal. The proposed interpolation method is more computational efficient than using large FFT sizes with zero padded data. The method can be used as part of the spectrum sensing function of cognitive radio handsets. The method was tested with both real-world captured signals and by simulation.
    01/2008;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The article provides basic information on the Dy-namic Spectrum Access platform developed by AAF Freeband project sponsored by the Dutch Ministry of Economic Affairs.
    01/2008;
  • Source
    M. Heskamp, C. H. Slump
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper contributes to the discussion about the usefulness of cyclostationary feature detection for the purpose of cognitive radio. From a simple but realistic radio signal model and an ideal channel, the power spectral density of the random signal component is derived, and compared with the periodical component that can be retrieved from the signal with a nonlinear operation.
    Computational Linguistics - COLI. 01/2008;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Today's rigid spectrum allocation scheme creates a spectrum scarcity problem for future wireless communications. Measurements show that a wide range of the allocated frequency bands are rarely used. Cognitive radio is a novel approach to improve the spectrum usage, which is able to sense the spectrum and adapt its transmission while coexisting with the licensed spectrum user. A reconfigurable radio platform is required to provide enough adaptivity for cognitive radio. In this paper, we propose a cognitive radio system architecture and discuss its possible implementation on a heterogeneous reconfigurable radio platform.
    Applied Physics Letters - APPL PHYS LETT. 01/2007;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Today's rigid spectrum allocation scheme creates a spectrum scarcity problem for future wireless communications. Measurements show that a wide range of the allocated frequency bands are rarely used. Cognitive radio is a novel approach to improve the spectrum usage, which is able to sense the spectrum and adapt its transmission while coexisting with the licensed spectrum user. A reconfigurable radio platform is required to provide enough adaptivity for cognitive radio. In this paper, we propose a cognitive radio system architecture and discuss its possible implementation on a heterogeneous reconfigurable radio platform
    Mobile Technology, Applications and Systems, 2005 2nd International Conference on; 12/2005
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In this paper we present node architecture for a personal node in a cognitive ad-hoc disaster relief network. This architecture is motivated from the network system requirements, especially single-hop distance and jamming-resilience requirements. It is shown that the power consumption of current-day analog to digital converters (ADCs) limits the channel bandwidth that can be used, both for a baseband processing system and the scanning system. We therefore propose to use a form of frequency hopping time division multiplexing (FH/TDD) system, similar to Bluetooth. However, we propose to use OFDM as modulation scheme instead of GFSK and show that the OFDM symbol length for the frequency range at hand (400-1000 MHz) is consistent with a Bluetooth-alike FH/TDD scheme. We propose to modify the FH/TDD scheme to incorporate a radio-spectrum measurement phase. Based on these measurements carriers in the OFDM-based scheme are selected in such a fashion that legacy users are avoided. In case of too much legacy-user spectral usage hopping patterns may be altered
    New Frontiers in Dynamic Spectrum Access Networks, 2005. DySPAN 2005. 2005 First IEEE International Symposium on; 12/2005
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The Adaptive Ad-hoc Free Band Wireless Communications (AAF) project is researching the possibility of using Software Defined Radio for wireless networks that needs to operate in an unknown or even hostile radio environment. Each node in the network needs to be cognitive of nearby transceivers in order to prevent radio frequency interference from and to other users and to survive jamming. So, in our system each node scans the radio spectrum to see which bands are free, so that these bands can be used for communication by the AAF network. The target application of our system is in a disaster relief wireless network. Since the chance of occurrence of a major emergency is very low, it will be very economical if the communication network of the rescue team can find free spectrum when it is needed, instead of reserving a fixed portion of the spectrum. In this paper we present a concept of a physical layer architecture of the scanning system of an AAF network node, and we will elaborate on the question of how it can be evaluated with of the shelf hardware.
    Journal of Materials Processing Technology - J MATER PROCESS TECHNOL. 01/2005;
  • M. Heskamp, C.H. Slump
    [Show abstract] [Hide abstract]
    ABSTRACT: In this paper we propose a combined signaling and spectrum sensing scheme for cognitive radio that can detect in-band primary users while the networks own signal is active. The signaling scheme uses OFDM with phase shift keying modulated sub-carriers, and the detection scheme measures the deviation of each sub-carrier from a circular shape.
  • Source
    M. Heskamp, R. Schiphorst, C.H. Slump
    [Show abstract] [Hide abstract]
    ABSTRACT: This book gives comprehensive and balanced coverage of the principles of cognitive radio communications, cognitive networks, and details of their implementation, including the latest developments in the standards and spectrum policy. Case studies, end-of-chapter questions, and descriptions of various platforms and test beds, together with sample code, give hands-on knowledge of how cognitive radio systems can be implemented in practice. Extensive treatment is given to several standards, including IEEE 802.22 for TV White Spaces and IEEE SCC41.