R. Moorfeld

Technische Universität Dresden, Dresden, Saxony, Germany

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Publications (15)0.17 Total impact

  • R. Moorfeld, Yun Lu, A. Finger
    [show abstract] [hide abstract]
    ABSTRACT: This paper presents optimal symbol constellations for M-PAM with energy detection receiver in fading channels. A significant gain in the symbol error probability can be achieved for medium to large degrees of freedom. We also present closed-form solutions for the symbol error probability in flat, approximated frequency selective and frequency selective fading channels. Independent and correlated fading has been considered. The assumption of Gaussian probability density functions based on the central limited theorem has not been used, because of the inaccuracy for low and medium degrees of freedom.
    Ultra-Wideband (ICUWB), 2012 IEEE International Conference on; 01/2012
  • Lu Li, Rainer Moorfeld, Adolf Finger
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    ABSTRACT: In this paper we present two different bit and power loading algorithms for the non-coherent multiband impulse UWB architecture. The first one is a very simple threshold based bit loading algorithm and an extension of the detect and avoid (DAA) algorithm presented in [1]. The second one is a more powerful algorithm, enabling also power loading. These algorithms allow a more efficient and flexible spectrum use, higher data rates and use less transmission power. The bit error rate performance is significantly improved. Both algorithms support inherent powerful DAA.
    01/2011;
  • Mingjun Li, Rainer Moorfeld, Adolf Finger
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    ABSTRACT: In this paper, different energy combining schemes for non-coherent UWB impulse radio systems are analysed. Closed form expressions for the Symbol Error Rate (SER) of Pulse Amplitude Modulation (PAM) using a non-coherent energy detection receiver with energy combining in the AWGN and fading channels are presented. The principle of energy combining is based on the fact that the symbol energy is combined in order to take advantage of the path diversity. Equal Gain Combining (EGC), Weighted Gain Combining (WGC) and Selection Combining (SC) are used as combining schemes, and the performance will be verified in AWGN and lognormal multipath UWB fading channels. Energy detection is also used for the detection of spectrum holes in cognitive radio environments.
    01/2011;
  • [show abstract] [hide abstract]
    ABSTRACT: This paper investigates robustness of a non-coherent multi-band impulse radio ultra-wideband communication system with respect to narrow-band interference. A statistical analysis of interference at the energy detector output gives insight into its impact and system dependency. Furthermore, the potential of interference mitigation is shown and verified with respect to the processing gain.
    Communications (ICC), 2010 IEEE International Conference on; 06/2010
  • [show abstract] [hide abstract]
    ABSTRACT: This paper considers low complex interference handling with regard to temporary narrowband interference occurrence within a non-coherent On-Off Keying based multiband impulse radio UWB system. The approach allows a precise and reliable sub-band specific on-line detection of narrowband interference's presence or absence within a packet's data phase. Due to the system's instability after detection of interference absence, a decision threshold replacement is applied to correctly demodulate the data packet's remaining possibly not interfered data bits. Hence, an increased flexibility with respect to efficient interference handling as well as a significant performance gain can be achieved.
    MELECON 2010 - 2010 15th IEEE Mediterranean Electrotechnical Conference; 05/2010
  • R. Moorfeld, A. Finger
    [show abstract] [hide abstract]
    ABSTRACT: This paper analyzes multilevel pulse amplitude modulation (M-PAM) for energy detection receivers. Because of the asymmetric, non Gaussian probability density function (PDF) of the energy detected signal, the optimal signal constellation is not known a priori. In order to achieve optimal symbol error rate performance using M-PAM, the optimal signal constellation will be calculated. Finally the SER performance of the energy detection receiver based multiband impulse radio UWB architecture within the IEEE802.15.3 a channel model using M-PAM will be demonstrated.
    Wireless Communications & Signal Processing, 2009. WCSP 2009. International Conference on; 12/2009
  • [show abstract] [hide abstract]
    ABSTRACT: This paper presents two easy to realize iterative coexistence approaches for non-coherent multi-band impulse radio ultra wide band systems with respect to multiple interference. Thereby, the global coexistence approach presented is extended to an iterative detection of possible interfered time-frequency gaps by means of an adaptive two-dimensional band plan. The proposed coexistence approaches can be applied for various periodic or constant operating broad-or narrow-band interfering signals. The iterative coexistence approaches outperform the global coexistence approach and hence contribute to more reliable interference detection under realistic dynamic interference scenarios.
    Ultra-Wideband, 2009. ICUWB 2009. IEEE International Conference on; 10/2009
  • Frequenz -Berlin- 10/2009; 63(9-10):200-204. · 0.17 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: When bringing a high data rate multiband impulse radio UWB system to the market it has to coexist with other already existing UWB technologies such as multiband OFDM UWB. This paper analyzes the interference impact of a multiband OFDM UWB system on a non-coherent multiband impulse radio UWB system. It is shown that the impact can be so dominant that communication within the impulse based multiband UWB system gets worse. For this reason a static as well as a dynamic coexistence approach are considered. The dynamic approach uses an efficient, robust and easy to realize ldquopixelrdquo based interference detection algorithm in conjunction with an adapted bandplan array. In comparison to the static approach, the dynamic coexistence approach allows higher data rates during data transmission phases without significant losses in bit error rate performance.
    Sarnoff Symposium, 2009. SARNOFF '09. IEEE; 05/2009
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: Not Available
    Spread Spectrum Techniques and Applications, 2008. ISSSTA '08. IEEE 10th International Symposium on; 09/2008
  • [show abstract] [hide abstract]
    ABSTRACT: Ultra-wideband (UWB) technology is currently investigated as one viable solution for high capacity short range indoor systems, because of its robustness in dense multipath environment, low cost and low power implementation, and the high bit rates achievable. In this paper we present the performance of coherent and non-coherent UWB receivers and especially for LDR-UWB systems with one of the most complicated application scenarios, under a realistic propagation environment, that takes into account also the effect of path-dependent pulse distortion. As far as coherent receivers are concerned, both maximal ratio combining (MRC) and equal gain combining (EGC) techniques are analyzed, considering a limited number of estimated paths.
    Wireless and Optical Communications Networks, 2005. WOCN 2005. Second IFIP International Conference on; 04/2005
  • Source
    R. Moorfeld, A. Finger, S. Zeisberg
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    ABSTRACT: The bit error rate (BER) performance of the imperfect digital matched filter (IDMF) receiver in a typical multiuser scenario assuming LOS conditions for the terminals is investigated. Due to the extremely high processing requirements of the digital matched filter, it is assumed that for an implementation the number of bits as well as the number of filter coefficients has to be as low as possible introducing implementation loss. Furthermore imperfect channel estimation is taken into account. The resulting BER performance of the IDMF receiver is compared to the BER performance of the ideal matched filter receiver. Additionally the BER performance of a coded IDMF receiver, which applies sophisticated turbo forward error correction coding, is investigated. The results show that the IDMF receiver can reach the uncoded target BER of 10<sup>-2</sup> in the environment investigated and that this uncoded BER corresponds to a coded BER of less than 10<sup>-6</sup>. For the IDMF receiver the required E<sub>b</sub>/N<sub>0</sub> ratio to achieve the target BER strongly depends on the number of filter coefficients.
    Spread Spectrum Techniques and Applications, 2004 IEEE Eighth International Symposium on; 01/2004
  • Source
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    ABSTRACT: Ultra-wideband Concepts for Ad-hoc Networks (U.C.A.N.) is an EU FP5 project which goal is to investigate theoretically and experimentally the characteristics of Ultra-wideband (UWB) radio communications. The U.C.A.N. demonstration platform for Impulse Radio UWB (IR-UWB) communications employs a correlation receiver. For risk management reasons the receiver correlator is limited in word width and in length of the correlation template. This paper analyses the different receiver blocks that use the output of the correlator as main input: the demodulator, the channel estimation and signal acquisition block, and the clock tracking block. Algorithm design trade-offs and implementation challenges are presented. Simulations show that this simplistic correlator approach still enables acceptable performances, both for demodulation (in term of BER) and synchronization (initial signal acquisition and clock tracking).
  • Source
    Michael Schmidt, Djordje Simic, Rainer Moorfeld
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    ABSTRACT: In this work the performance of low data rate Ultra-Wideband (UWB) devices is studied. The most important design constraint is low complexity and low power consumption. Four different architectures of different complexity are built in a modular approach from functional blocks. The trade-offs of these architectures between performance and complexity are shown.
  • Source
    Martin Mittelbach, Rainer Moorfeld, Adolf Finger
    [show abstract] [hide abstract]
    ABSTRACT: In this paper a highly flexible and scaleable multiband impulse radio UWB architecture for high data rates is described and evaluated. The investigations are mainly focused on on-off-keying modulation combined with a low-complexity non-coherent energy detection receiver. Various representative system configurations are defined and examined by simulation, studying effects of pulse gener-ation, filtering, synchronization, demodulation and channel coding. Keywords— Ultra-wideband, multiband impulse radio, on-off-keying, non-coherent energy detection.

Publication Stats

38 Citations
0.17 Total Impact Points

Top Journals

Institutions

  • 2004–2012
    • Technische Universität Dresden
      • Communications Laboratory
      Dresden, Saxony, Germany
  • 2009–2010
    • Karlsruhe Institute of Technology
      • Communications Engineering Lab (CEL)
      Karlsruhe, Baden-Wuerttemberg, Germany