Change search
Refine search result
1234567 51 - 100 of 343
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • 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.
  • 51.
    De Angelis, Alessio
    et al.
    KTH, School of Electrical Engineering (EES), Signal Processing.
    Dwivedi, Satyam
    KTH, School of Electrical Engineering (EES), Signal Processing.
    Händel, Peter
    KTH, School of Electrical Engineering (EES), Signal Processing.
    An Experimental UWB Radio Platform for Indoor Positioning2012Conference paper (Other academic)
  • 52.
    De Angelis, Alessio
    et al.
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre. University of Perugia, Italy.
    Dwivedi, Satyam
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Händel, Peter
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Application of time-to-digital converters to radio-frequency distance measurement2013In: NoMe - TDC 2013 - 2013 IEEE Nordic Mediterranean Workshop on Time to Digital Converters, Proceedings, 2013, p. 31-35Conference paper (Refereed)
    Abstract [en]

    The application of TDCs to wireless distance measurement problems is evaluated by means of experimental tests using a realized system. The system is capable of measuring the round-trip-time of ultra-wideband radio pulses propagating between two active transceivers, utilizing a commercial TDC with sub-nanosecond resolution. The results show an operational range of approximately 30 m in an indoor environment, with a distance-measurement error of less than 0.5 m in approximately 90% of the considered cases. Further, a discussion of the fundamental error sources is provided, analyzing the effect of RF interference, timing jitter, received signal strength, and propagation conditions.

  • 53.
    De Angelis, Alessio
    et al.
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Dwivedi, Satyam
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Händel, Peter
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Characterization of a Flexible UWB Sensor for Indoor Localization2013In: IEEE Transactions on Instrumentation and Measurement, ISSN 0018-9456, E-ISSN 1557-9662, Vol. 62, no 5, p. 905-913Article in journal (Refereed)
    Abstract [en]

    This paper presents research to develop an ultrawideband ranging sensor for personnel indoor localization based on the measurement of the pulse round-trip time. An approach combining flexibility, a high measurement update rate, and asynchronous operation with digital processing capability has been employed in the design of the sensor. The principle of operation, the architecture of the realized sensor, and the experimental setup are described. Finally, the results of a ranging calibration and validation test are presented and discussed. In the validation procedure, a root-mean-square error of 29 cm and a maximum absolute error of 81 cm with an operational range of approximately 10 m were observed.

  • 54.
    De Angelis, Alessio
    et al.
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Dwivedi, Satyam
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Händel, Peter
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Development of a radio front end for a UWB ranging embedded test bed2012In: Ultra-Wideband (ICUWB), 2012 IEEE International Conference on, IEEE , 2012, p. 31-35Conference paper (Refereed)
    Abstract [en]

    In this paper, we present a modular test bed for ultra wideband ranging. The test bed comprises a 6.5 GHz radio front end interfacing with a baseband pulse transceiver and round-trip-time measurement module and with a flexible digital control and processing platform. The proposed radio front end allows to reduce antenna size and interference from narrowband users, with respect to the baseband pulse transceiver. We provide experimental characterization results, therefore proving the concept for the proposed front end architecture in the context of the considered UWB test bed.

  • 55.
    De Angelis, Alessio
    et al.
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Dwivedi, Satyam
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Händel, Peter
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Development of a test bed for UWB radio indoor localization of first responders2012In: 2012 IEEE/ION Position Location And Navigation Symposium (PLANS), IEEE , 2012, p. 1106-1110Conference paper (Refereed)
    Abstract [en]

    This paper presents the architecture of a test bed for indoor localization based on pulse Ultra-Wideband radio technology, mainly considering the localization of first responders as a target application. A modular design approach has been employed, therefore enabling comparison of different solutions and implementation of sensor fusion techniques for localization. The realized test bed provides range estimates based on the round-trip time of radio pulses, which is accurately measured by a time-to-digital converter without the need for nano-second-level clock synchronization. Furthermore, support for digital control and processing of the acquired raw data is provided by a field programmable gate array, allowing for flexibility and reconfigurability. Results of a preliminary characterization of the test bed are presented.

  • 56.
    De Angelis, Alessio
    et al.
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Dwivedi, Satyam
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Händel, Peter
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Moschitta, A.
    Carbone, P.
    Ranging results using a UWB platform in an indoor environment2013In: 2013 International Conference on Localization and GNSS, ICL-GNSS 2013, IEEE , 2013, p. 6577273-Conference paper (Refereed)
    Abstract [en]

    This paper presents an impulse-radio UWB experimental platform for ranging and positioning in GNSS-challenged environments. The platform is based on the two-way time-of-arrival principle of operation, which reduces architecture complexity and relaxes the synchronization requirements with respect to time-of-arrival or time-difference-of-arrival solutions. The modular architecture of the platform is described together with the design and features of its main components, namely the 5.6-GHz RF front end and the baseband module for measurement and processing. A set of experimental results obtained using the realized platform in an indoor office environment is presented and discussed. The platform provides a maximum range of about 30 m in line-of-sight conditions with an RMSE of the order of 40 cm.

  • 57.
    De Angelis, Alessio
    et al.
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Fischione, Carlo
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Händel, Peter
    KTH, School of Electrical Engineering (EES), Signal Processing.
    A Sensor Fusion Algorithm for Mobile Node Localization2011In: 18th World Congress of the International Federation of Automatic Control (IFAC), 2011Conference paper (Refereed)
    Abstract [en]

    Accurate  distributed  estimation  of the position  of network  nodes  is essential  formany  applications,  including  localization,  geographic  routing,  and  vehicular  networks.  When nodes are mobile and their mobility pattern is unknown,  there are not yet adequate techniques to achieve high accuracy  and  low estimation errors.  In this paper,  a new distributed estimator of the position of mobile nodes is proposed.  No model of the mobility is assumed.  The estimator combines heterogeneous  information coming from pre-existing ranging, speed, and angular measurements,  which  is jointly  fused  by  an  optimization  problem  where  the squared  mean and variance  of the localization error is minimized. Challenges of this optimization are the characterization  of the moments  of the noises  that affect  the measurements.  The  estimator is distributed  in that it  requires  only  local processing  and  communication  among  the nodes of the network.  Numerical  results  show that the proposed  estimator  outperforms traditionalapproaches based on the extended Kalman  filter.

  • 58.
    De Angelis, Alessio
    et al.
    KTH, School of Electrical Engineering (EES), Signal Processing.
    Händel, Peter
    KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre. KTH, School of Electrical Engineering (EES), Signal Processing.
    Rantakokko, Jouni
    FOI Swedish Defence Research Agency, Linköping, Sweden.
    Measurement report. Laser total station campaign in KTH R1 for Ubisense system accuracy evaluation: Laser total station campaign in KTH R1 for Ubisense system accuracy evaluation2012Report (Other academic)
  • 59.
    De Angelis, Alessio
    et al.
    DIEI, University of Perugia, Italy.
    Moschitta, Antonio
    DIEI, University of Perugia, Italy.
    Händel, Peter
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Carbone, Paolo
    DIEI, University of Perugia, Italy.
    Experimental Radio Indoor Positioning Systems Based on Round-Trip Time Measurement2010In: Advances in Measurement Systems / [ed] Milind Kr Sharma, InTech , 2010, p. 195-220Chapter in book (Other academic)
  • 60.
    De Angelis, Alessio
    et al.
    KTH, School of Electrical Engineering (EES), Signal Processing.
    Nilsson, John Olof
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Skog, Isaac
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Händel, Peter
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Carbone, P.
    Indoor positioning by ultra wide band radio aided inertial navigation2009In: 19th IMEKO World Congress 2009, 2009, p. 450-455Conference paper (Refereed)
    Abstract [en]

    In this paper, a research activity aimed at developing an indoor positioning system is presented. The realized system prototype uses sensor fusion techniques to combine information from two sources: a local Ultra-Wideband (UWB) radio based distance-measuring system infrastructure and an Inertial Navigation System (INS). The UWB system provides a measure of distance between two transceivers by measuring the time-of-flight of pulses. Its principle of operation is briefly described, together with the main features of its architecture. Furthermore, the main characteristics of the INS and of the Extended Kalman Filter information fusion approach are presented. Finally, some experimental results are provided, relative to static and dynamic position measurements.

  • 61.
    De Angelis, Alessio
    et al.
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Nilsson, John Olof
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Skog, Isaac
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Händel, Peter
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Carbone, Paolo
    Indoor positioning by ultra wide band radio aided inertial navigation2010In: Metrology and Measurement Systems, ISSN 0860-8229, Vol. 17, no 3, p. 447-460Article in journal (Refereed)
    Abstract [en]

    A research study aimed at developing a novel indoor positioning system is presented. The realized system prototype uses sensor fusion techniques to combine information from two sources: an in-house developed local Ultra-Wideband (UWB) radio-based ranging system and an inertial navigation system (INS). The UWB system measures the distance between two transceivers by recording the round-trip-time (RTT) of UWB radio pulses. Its principle of operation is briefly described, together with the main design features. Furthermore, the main characteristics of the INS and of the Extended Kalman Filter information fusion approach are presented. Finally, selected static and dynamic test scenario experimental results are provided. In particular, the advantages of the proposed information fusion approach are further investigated by means of a high dynamic test scenario.

  • 62.
    De Angelis, Alessio
    et al.
    KTH, School of Electrical Engineering (EES), Signal Processing.
    Nilsson, John-Olof
    KTH, School of Electrical Engineering (EES), Signal Processing.
    Skog, Isaac
    KTH, School of Electrical Engineering (EES), Signal Processing.
    Händel, Peter
    KTH, School of Electrical Engineering (EES), Signal Processing.
    UWB Ranging Hardware Platform2010In: GigaHertz Symposium, Lund, Sweden, 2010Conference paper (Other academic)
  • 63.
    De Angelis, Guido
    et al.
    DIEI, University of Perugia, Italy.
    De Angelis, Alessio
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Händel, Peter
    KTH, School of Electrical Engineering (EES), Signal Processing.
    Carbone, Paolo
    DIEI, University of Perugia, Italy.
    Estimation of the Calibration Parameters for an UWB Indoor Positioning System2010In: European Navigation Conference on Global Navigation Satellite Systems (ENC GNSS), 2010Conference paper (Refereed)
  • 64.
    del Aguila Pla, Pol
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering.
    Pellaco, Lissy
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering.
    Dwivedi, Satyam
    Ericsson Research.
    Händel, Peter
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering.
    Jaldén, Joakim
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering.
    Clock synchronization over networks - Identifiability of the sawtooth modelManuscript (preprint) (Other academic)
    Abstract [en]

    In this paper, we analyze the two-node joint clocksynchronization and ranging problem. We focus on the case of nodes that employ time-to-digital converters to determine the range between them precisely. This specific design leads to a sawtooth model for the captured signal, which has not been studied in detail before from an estimation theory standpoint. In the study of this model, we recover the basic conclusion of a well-known article by Freris, Graham, and Kumar in clock synchronization. Additionally, we discover a surprising identifiability result on the sawtooth signal model: noise improves the theoretical condition of the estimation of the phase and offset parameters. To complete our study, we provide performance references for joint clock synchronization and ranging. In particular, we present the Cramér-Rao lower bounds that correspond to a linearization of our model, as well as a simulation study on the practical performance of basic estimation strategies under realistic parameters. With these performance references, we enable further research in estimation strategies using the sawtooth model and pave the path towards industrial use.

  • 65.
    Dwivedi, Satyam
    et al.
    KTH, School of Electrical Engineering (EES), Signal Processing.
    De Angelis, Alessio
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Händel, Peter
    KTH, School of Electrical Engineering (EES), Signal Processing.
    A Wideband Interference Power Estimator using a 1-bit Quantizer2011In: 2011 IEEE 22nd International Symposium On Personal Indoor And Mobile Radio Communications (PIMRC), New York: IEEE , 2011, p. 515-519Conference paper (Refereed)
    Abstract [en]

    This paper proposes a power estimation methodology which presents low complexity when implemented in hardware. Power estimation is done in digital and the radio signals are digitized using a 1-bit quantizer. An algorithm to estimate power is proposed. Power estimation of the signal is done while varying the threshold of the 1-bit quantizer. It is also shown that the proposed architecture can be used to estimate power of wideband radio channels.

  • 66.
    Dwivedi, Satyam
    et al.
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    De Angelis, Alessio
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Händel, Peter
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Scheduled UWB pulse transmissions for cooperative localization2012In: Ultra-Wideband (ICUWB), 2012 IEEE International Conference on, IEEE , 2012, p. 6-10Conference paper (Refereed)
    Abstract [en]

    In this paper we have proposed a technique for cooperative localization where localization is done in distributive fashion without using any additional broadcast by nodes. The method relies on a fixed scheduled ultra-wideband (UWB) pulse transmissions by nodes in a predetermined way. The advantages of the proposed method is simpler hardware, comparatively less pulse transmission in the system hence energy efficient and faster update rate.

  • 67.
    Dwivedi, Satyam
    et al.
    KTH, School of Electrical Engineering (EES), Signal Processing.
    De Angelis, Alessio
    Zachariah, Dave
    Händel, Peter
    KTH, School of Electrical Engineering (EES), Signal Processing.
    Joint Ranging and Clock Parameter Estimation by Wireless Round Trip Time Measurements2015In: IEEE Journal on Selected Areas in Communications, ISSN 0733-8716, E-ISSN 1558-0008, Vol. 33, no 11, p. 2379-2390Article in journal (Refereed)
    Abstract [en]

    In this paper, we develop a new technique for estimating fine clock errors and range between two nodes simultaneously by two-way time-of-arrival measurements using impulse-radio ultrawideband signals. Estimators for clock parameters and the range are proposed, which are robust with respect to outliers. They are analyzed numerically and by means of experimental measurement campaigns. The technique and derived estimators achieve accuracies below 1 Hz for frequency estimation, below 1 ns for phase estimation, and 20 cm for range estimation, at a 4-m distance using 100-MHz clocks at both nodes. Therefore, we show that the proposed joint approach is practical and can simultaneously provide clock synchronization and positioning in an experimental system.

  • 68.
    Dwivedi, Satyam
    et al.
    KTH, School of Electrical Engineering (EES), Signal Processing.
    Händel, Peter
    KTH, School of Electrical Engineering (EES), Signal Processing.
    Precise Clock Parameter Estimation and Ground Truth Capture for Clock Error Measurements using FPGAs2014In: 2014 IEEE International Symposium on Precision Clock Synchronization for Measurement, Control and Communication (ISPCS), IEEE , 2014, p. 83-86Conference paper (Refereed)
    Abstract [en]

    In this extended abstract we discuss and propose a mechanism to estimate clock parameters between two clocks using TDC. Simultaneously, we have proposed a ground truth capture methodology for clock error measurements. In particular, we have proposed an accurate way of measuring clock phase ground truth at any instant in time using delay lines in FPGA. Accuracy of clock phase ground truth measurement can be up to 16 ps. We have estimated clock parameters from measurements and have compared it with clock ground truth obtained using suggested methods. Relative frequency errors are estimated with RMSE of 0.46 Hz and phase error is estimated with RMSE of 0.29 ns.

  • 69.
    Dwivedi, Satyam
    et al.
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Zachariah, Dave
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    De Angelis, Alessio
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Händel, Peter
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Cooperative Decentralized Localization Using Scheduled Wireless Transmissions2013In: IEEE Communications Letters, ISSN 1089-7798, E-ISSN 1558-2558, Vol. 17, no 6, p. 1240-1243Article in journal (Refereed)
    Abstract [en]

    In this letter we develop a solution for decentralized localization of transceiving nodes in wireless networks. By exploiting a common transmission schedule, this is achieved without any additional communication and dispels the need for synchronized nodes. We derive the Cramer-Rao bounds for the solution and formulate two practical estimators for localization. Finally, the solution and estimators are tested in numerical experiments.

  • 70. Falk, J.
    et al.
    Händel, Peter
    KTH, Superseded Departments, Signals, Sensors and Systems.
    Jansson, Magnus
    KTH, Superseded Departments, Signals, Sensors and Systems.
    Estimation of receiver frequency error in a TDOA-based direction-finding system2004In: Conference Record - Asilomar Conference on Signals, Systems and Computers, 2004, Vol. 2, p. 2079-2083Conference paper (Refereed)
    Abstract [en]

    Direction-finding of radio transmitters is considered and in particular correlation-based time-difference-of-arrival (TDOA) estimation between a pair of intercept receivers. In the target application, the received and down-converted signals are corrupted by a frequency error due to a receiver frequency tuning offset which degrades the performance of the TDOA estimation. Traditionally, the cross-ambiguity function (CAP) is used in a 2D scheme for joint TDOA and frequency error estimation. In this paper, sequential ID frequency error and TDOA estimators are introduced and compared to the 2D method. The 2D method attains the CRLB for both the TDOA and frequency error estimates, but have high computational and memory complexity. The proposed frequency error estimator is outperformed by the 2D method. However, the main objective is to estimate the TDOA and the proposed TDOA estimator have a performance similar to that of the 2D method. The main advantage of the proposed method is a reduction in both computational and memory complexity.

  • 71. Falk, J.
    et al.
    Händel, Peter
    KTH, Superseded Departments, Signals, Sensors and Systems.
    Jansson, Magnus
    KTH, Superseded Departments, Signals, Sensors and Systems.
    Multisource time delay estimation subject to receiver frequency errors2003In: CONFERENCE RECORD OF THE THIRTY-SEVENTH ASILOMAR CONFERENCE ON SIGNALS, SYSTEMS & COMPUTERS, VOLS 1 AND 2 / [ed] Matthews, MB, 2003, p. 1156-1160Conference paper (Refereed)
    Abstract [en]

    An electronic warfare (EW) system with two spatially separated intercept receivers, targeting military communication systems is considered. The EW system estimates the direct ion-of-arrival via a correlation-based time-difference-of-arrival (TDOA) method without any prior knowledge of the signals-of-interest. An important practical consideration is the oscillator frequencies of the two intercept receivers where a difference, or error, degrades the TDOA estimator performance. A measure of this degradation, or loss in power due to the frequency error, is derived and used to describe the robustness against receiver frequency errors. In the multisource scenario, time and frequency overlapping sources can be separated using direction-filtering of the cross-correlation function between the receiver outputs with good result if one signal at a time can be selected by the direction-filter. However, the performance of the considered estimator is degraded in a multisource scenario compared to the single source case.

  • 72.
    Falk, Johan
    et al.
    KTH, Superseded Departments, Signals, Sensors and Systems.
    Händel, Peter
    KTH, Superseded Departments, Signals, Sensors and Systems.
    Jansson, Magnus
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Direction Finding for Electronic Warfare Systems Using the Phase of the Cross Spectral Density2002In: RadioVetenskap och Kommunikation (RVK), 2002, p. 264-268Conference paper (Refereed)
    Abstract [en]

    In modern electronic warfare systems there is a need for direction-finding of transmitters using waveforms for military stealth communication. In this paper, a correlation-based method is investigated utilizing the phase of the cross spectral density to estimate the time-difference-of-arrival from a two-channel digital receiver. A least squares method is reviewed, and its performance is investigated by theoretical analysisand by Monte-Carlo simulations. Proper Cramér-Raobounds are derived. It is shown that the method is statistically efficient for flat spectrum signals. The method is found to be a promising method for use against military communication in an electronic warfare direction-finding system.

  • 73.
    Falk, Johan
    et al.
    Department of Electronic Warfare Systems, Swedish Defence Research Agency Linköping, Sweden.
    Händel, Peter
    KTH, Superseded Departments, Signals, Sensors and Systems.
    Jansson, Magnus
    KTH, Superseded Departments, Signals, Sensors and Systems.
    Effects of frequency and phase error in electronic warfare TDOA direction-finding systems2003In: Military Communications Conference, IEEE conference proceedings, 2003, p. 118-123Conference paper (Refereed)
    Abstract [en]

    Electronic warfare systems for use against military communication sources include direction-finding. The considered direction-finding electronic-warfare system usestwo intercept receivers which is eavesdropping on thetransmitted signal with no knowledge of the waveformused, or its origin. Down-conversion to baseband is required in order to digitize the received signal. This canbe done using a superheterodyne receiver where an oscillator is used to mix the signal-of-interest to baseband.Errors in frequency and phase between the oscillatorsdegrade the performance. Because of this error, the per-formance derived in previous work by the authors willnot apply since the used model no longer is applicable.The extended model presented here considers the oscil-lator errors. The performance using the extended modelis determined numerically and the result is compared tothe Cramer-Rao lower bound for the ideal system usinga typical signal waveform.

  • 74. Fritzin, Jonas
    et al.
    Jung, Ylva
    Landin, Per Niklas
    KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre. KTH, School of Electrical Engineering (EES), Signal Processing.
    Händel, Peter
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Enqvist, Martin
    Alvandpour, Atila
    Phase Predistortion of a Class-D Outphasing RF Amplifier in 90 nm CMOS2011In: IEEE Transactions on Circuits and Systems - II - Express Briefs, ISSN 1549-7747, E-ISSN 1558-3791, Vol. 58, no 10, p. 642-646Article in journal (Refereed)
    Abstract [en]

    This brief presents a behavioral model structure and a model-based phase-only predistortion method that are suitable for outphasing RF amplifiers. The predistortion method is based on a model of the amplifier with a constant gain factor and phase rotation for each outphasing signal, and a predistorter with phase rotation only. The method has been used for enhanced data rates for GSM evolution (EDGE) and wideband code-division multiple-access (WCDMA) signals applied to a Class-D outphasing RF amplifier with an on-chip transformer used for power combining in 90-nm CMOS. The measured peak power at 2 GHz was +10.3 dBm with a drain efficiency and power-added efficiency of 39% and 33%, respectively. For an EDGE 8 phase-shift-keying (8-PSK) signal with a phase error of 3 degrees between the two input outphasing signals, the measured power at 400 kHz offset was -65.9 dB with predistortion, compared with -53.5 dB without predistortion. For a WCDMA signal with the same phase error between the input signals, the measured adjacent channel leakage ratio at 5-MHz offset was -50.2 dBc with predistortion, compared with -38.0 dBc without predistortion.

  • 75.
    Gholami, Mohammad Reza
    et al.
    KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Dwivedi, Satyam
    KTH, School of Electrical Engineering (EES), Signal Processing.
    Jansson, Magnus
    KTH, School of Electrical Engineering (EES), Signal Processing.
    Händel, Peter
    KTH, School of Electrical Engineering (EES), Signal Processing.
    Ranging without time stamps exchanging2015In: ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings, IEEE conference proceedings, 2015, p. 3981-3985Conference paper (Refereed)
    Abstract [en]

    We investigate the range estimate between two wireless nodes without time stamps exchanging. Considering practical aspects of oscillator clocks, we propose a new model for ranging in which the measurement errors include the sum of two distributions, namely, uniform and Gaussian. We then derive an approximate maximum likelihood estimator (AMLE), which poses a difficult global optimization problem. To avoid the difficulty in solving the complex AMLE, we propose a simple estimator based on the method of moments. Numerical results show a promising performance for the proposed technique.

  • 76. Girisha, R.
    et al.
    Prateek, G. V.
    Hari, K. V. S.
    Händel, Peter
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Fusing the navigation information of dual foot-mounted zero-velocity-update-Aided inertial navigation systems2014In: 2014 International Conference on Signal Processing and Communications, SPCOM 2014, Institute of Electrical and Electronics Engineers , 2014Conference paper (Refereed)
    Abstract [en]

    A range constraint method viz. centroid method is proposed to fuse the navigation information of dual (right and left) foot-mounted Zero-velocity-UPdaTe (ZUPT)-Aided Inertial Navigation Systems (INSs). Here, the range constraint means that the distance of separation between the position estimates of right and left foot ZUPT-Aided INSs cannot be greater than a quantity known as foot-to-foot maximum separation. We present the experimental results which illustrate the applicability of the proposed method. The results show that the proposed method significantly enhances the accuracy of the navigation solution when compared to using two uncoupled foot-mounted ZUPT-Aided INSs. Also, we compare the performance of the proposed method with the existing data fusion methods.

  • 77. Gupta, Amit K.
    et al.
    Skog, Isaac
    KTH, School of Electrical Engineering (EES), Signal Processing.
    Händel, Peter
    KTH, School of Electrical Engineering (EES), Signal Processing.
    Long-term Performance Evaluation of a Foot-mounted Pedestrian Navigation Device2015In: 2015 ANNUAL IEEE INDIA CONFERENCE (INDICON), 2015Conference paper (Refereed)
    Abstract [en]

    In this paper, we present a long term experimental study performed on a foot mounted pedestrian navigation device, the Osmium MIMU22BTP, which is based on the OpenShoe platform. The aim of the study is to investigate the performance that can be expected in mass market applications. Accordingly, we investigate the error characteristics over a large number of tracking devices and their alternative mounting schemes, over several wearers, and over different walking scenarios. By a massive data collection corresponding to more than 150 km of elapsed walking distance over almost 1,000 independent tests, the law of large numbers provides us with illustrative rule-of-thumbs for the tracking performance in realistic use cases. We observe no outlier performance and relative errors less than 4% in 95% of the test-cases, indicating its potential for a variety of indoor Location Based Services (LBS) and IoT applications based on foot-mounted inertial sensing and dead reckoning. The experimental findings are validated with long distance walks.

  • 78.
    Hari, K.V.S.
    et al.
    Indian Institute of Science (IISc).
    Nilsson, John-Olof
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Skog, Isaac
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Händel, Peter
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Rantakokko, Jouni
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Prateek, G.V.
    Indian Institute of Science (IISc).
    A prototype of a first-responder indoor localization system2013In: Journal of the Indian Institute of Science, ISSN 0970-4140, Vol. 93, no 3, p. 511-520Article, review/survey (Refereed)
    Abstract [en]

    In this paper we present an approach to build a prototype. model of a first-responder localization system intended for disaster relief operations. This system is useful to monitor and track the positions of the first-responders in an indoor environment, where GPS is not available. Each member of the first responder team is equipped with two zero-velocity-update-aided inertial navigation systems, one on each foot, a camera mounted on a helmet, and a processing platform strapped around the waist of the first responder, which fuses the data from the different sensors. The fusion algorithm runs real-time on the processing platform. The video is also processed using the DSP core of the computing machine. The processed data consisting of position, velocity, heading information along with video streams is transmitted to the command and control system via a local infrastructure WiFi network. A centralized cooperative localization algorithm, utilizing the information from Ultra Wideband based inter-agent ranging devices combined with the position estimates and uncertainties of each first responder, has also been implemented.

  • 79. Host-Madsen, A.
    et al.
    Händel, Peter
    KTH, Superseded Departments, Signals, Sensors and Systems.
    Effects of sampling and quantization on single-tone frequency estimation2000In: IEEE Transactions on Signal Processing, ISSN 1053-587X, E-ISSN 1941-0476, Vol. 48, no 3, p. 650-662Article in journal (Refereed)
    Abstract [en]

    The effects of sampling and quantization on frequency estimation for a single sinusoid are investigated. Cramer-Rao bound for I-bit quantization is derived and compared with the limit of infinite quantization. It is found that I-bit quantization gives a slightly worse performance, however, with a dramatic increase of variance at certain frequencies. This can be avoided by using four times ol oversampling. The effect of sampling when using nonideal antialiasing lowpass filters is therefore investigated through derivation of the Cramer-Rao lower bounds. Finally, fast estimators for 1-bit quantization, in particular, correlation-based estimators, are derived,and their performance is investigated. The paper is concluded with simulation results for fourtimes oversampled I-bit quantization.

  • 80. Host-Madsen, A.
    et al.
    Händel, Peter
    The effect of sampling and quantization on frequency estimation1998In: 1998 IEEE International Conference on Acoustics, Speech and Signal Processing, ICASSP, 1998, Vol. 4, p. 2217-2220Conference paper (Refereed)
    Abstract [en]

    The effect of sampling and quantization on frequency estimation for a single sinusoid is investigated. The Cramer-Rao bound for 1 bit quantization is derived, and compared with the limit of infinite quantization. It is found that 1 bit quantization gives a slightly worse performance, however, with a dramatic increase of variance at certain frequencies. This can be avoided by using 4 times oversampling. The effect of sampling when using non-ideal antialiasing lowpass filters is therefore investigated. Cramer-Rao lower bounds are derived, and the optimal filters and sampling frequencies are found. Finally, fast estimators for 1 bit sampling, in particular correlation based estimators, are derived. The paper concludes with simulation results for 4 times oversampled 1 bit quantization

  • 81.
    Händel, Peter
    Tampere University of Technology.
    Adaptive nonlinear modeling of periodic signals1997In: The First European Conference on Signal Analysis and Prediction, ECSAP-97, Prague, Czech Republic,24-27 June 1997, 1997, p. 133-136Conference paper (Refereed)
  • 82.
    Händel, Peter
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Amplitude estimation using IEEE-STD-1057 three-parameter sine wave fit: Statistical distribution, bias and variance2010In: Measurement, ISSN 0263-2241, E-ISSN 1873-412X, Vol. 43, no 6, p. 766-770Article in journal (Refereed)
    Abstract [en]

    There has been a recent interest on the performance of amplitude estimation employing a coherently sampled sinusoidal model to noisy measurements. In [F. Correa Alegria, Bias of amplitude estimation using three-parameter sine fitting in the presence of additive noise, Measurement 42 (2009) 748-756.], several issues regarding the bias of the amplitude estimate were studied. In this work, the results are generalized to include a description of the distribution of the amplitude estimate, with explicit results on bias and variance as by-products. Simple closed form expressions for bias and variance are derived. It is shown that the amplitude estimate in finite samples obeys a Rician distribution. The biased amplitude estimator is also shown to beat all unbiased estimators in terms of mean square error, in a wide spread of scenarios.

  • 83.
    Händel, Peter
    KTH, Superseded Departments, Signals, Sensors and Systems.
    Compensation for saturation effects in FIR-NLMS system identification1998In: Electronics Letters, ISSN 0013-5194, E-ISSN 1350-911X, Vol. 34, no 4, p. 411-412Article in journal (Refereed)
    Abstract [en]

    An adaptive scheme is derived to be used in combination with the normalised least mean squares algorithm for finite impulse response models (FIR-NLMS), to combat nonlinear imperfections of the plant to be identified. The scheme is shown to outperform FIR-NLMS when a test system that consists of a variable static nonlinearity in cascade with a linear filter is identified.

  • 84.
    Händel, Peter
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Cramér-Rao bounds and non-linear least squares for a seven parameter dual channel sinewave model2007In: 2007 IEEE Instrumentation and Measurement Technology Conference, IEEE , 2007, p. 79-84Conference paper (Refereed)
    Abstract [en]

    The Cramer-Rao bound (CRB) is a lower bound on the error variance of any estimator. For a Gaussian scenario, the CRB is derived for a seven parameter dual channel sine wave model; a model with relevance in applications like impedance measurements and the estimation of particle size and velocity by laser anemometry. Three different parameterizations are considered: the common quadrature/in-phase and amplitude-phase models, as well as a relative amplitude-phase model. The CRB indicates the achievable error variance of an unbiased estimator as a function of the signal-to-noise ratio, number of samples, and noise power. An non-optimal non-linear least squares fit of the signal model to the collected data is employed. The problem at hand is separable and can be solved by a one dimensional search followed by a linear least-squares fit of the remaining parameters. The performance of the method is investigated by aid of a simulation study, and the outcome is compared with the corresponding CRB. For high signal-to-noise ratios, the performance of the proposed method is close to optimal with an error variance close to the predictions made by the CRB.

  • 85.
    Händel, Peter
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Discounted Least-Squares Gearshift Detection Using Accelerometer Data2009In: IEEE Transactions on Instrumentation and Measurement, ISSN 0018-9456, E-ISSN 1557-9662, Vol. 58, no 12, p. 3953-3958Article in journal (Refereed)
    Abstract [en]

    A gearshift detector based on accelerometer readings is derived, and its performance is investigated with the aid of experimental data. The employed methodology contains a low-order parametric model of the acceleration performed by the vehicle in combination with the minimization of a fading-memory least-squares criterion for parameter estimation and tracking. It is shown that the resulting filtering equations converge so that filtered accelerometer outputs (i.e., instantaneous acceleration and its rate of change) are obtained by linear time-invariant filtering of the raw accelerometer data, where the tradeoff between noise suppression and tracking ability is entirely determined by a single user-chosen variable. Two detection variables are formed, and they are combined to produce the detector output. Evaluation on experimental data illustrates the potential of the proposed method.

  • 86.
    Händel, Peter
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Evaluation of a standardized sine wave fit algorithm2000In: Proceedings Nordic Signal Processing Symposium, 2000, p. 453-456Conference paper (Refereed)
  • 87.
    Händel, Peter
    Uppsala universitet.
    Forssen method for notch filter synthesis1995In: IEEE transactions on circuits and systems. 2, Analog and digital signal processing (Print), ISSN 1057-7130, E-ISSN 1558-125X, Vol. 42, no 5, p. 364-366Article in journal (Refereed)
    Abstract [en]

    The synthesis procedure in [1] is applied to different notch filter structures with constrained parameters. Asymptotic results that give analytical insight into notch filter synthesis using parameter constrained filter structures are derived.

  • 88.
    Händel, Peter
    KTH, Superseded Departments, Signals, Sensors and Systems.
    Frequency selective adaptive time delay estimation1999In: IEEE Transactions on Signal Processing, ISSN 1053-587X, E-ISSN 1941-0476, Vol. 47, no 2, p. 532-535Article in journal (Refereed)
    Abstract [en]

    A frequency-selective algorithm for time delay estimation between two channel data is proposed, and its performance is studied. The adaptive stochastic gradient scheme pro\ides a direct estimate of the time delay, It has a low numerical complexity, and it is an alternative to data prefiltering and time delay estimation when the source and noise components have different spectral characteristics.

  • 89.
    Händel, Peter
    KTH, Superseded Departments, Signals, Sensors and Systems.
    Frequency-estimation error variance of an adaptive scheme based on structured AR modeling1999In: IEEE transactions on circuits and systems. 2, Analog and digital signal processing (Print), ISSN 1057-7130, E-ISSN 1558-125X, Vol. 46, no 11, p. 1361-1366Article in journal (Refereed)
    Abstract [en]

    An on-line version of a recently proposed frequency-estimation algorithm based on structured autoregressive (AK) modeling of data is derived for the special case of a single cisoid in noise. The adaptive notch filter utilizes a weighted sum-of-squares of the AR prediction error that is recursively minimized with respect to the frequency of the cisoid. The steady-state performance of the algorithm is characterized by aid of a linear filter-approximation technique, and design rules for the tuning variables are given, An excellent agreement is demonstrated between the results predicted by theory, and the measured performance based on numerical simulations. The tracking ability and noise rejection is compared both with the performance of alternative algorithms and with the appropriate Cramer-Rao bound. It is shown that the algorithm is close to being statistically efficient.

  • 90.
    Händel, Peter
    Uppsala universitet.
    High-order Yule-Walker estimation of the parameters of exponentially damped cisoids in noise1993In: Signal Processing, ISSN 0165-1684, E-ISSN 1872-7557, Vol. 32, no 3, p. 315-328Article in journal (Refereed)
    Abstract [en]

    An approach for the estimation of the frequencies and damping factors of exponentially damped cisoids (complex sinusoids) is presented. The method may be seen as an extension of the method of backward linear prediction and singular value decomposition of Kumaresan and Tufts to the second-order statistics domain. The proposed estimator is interpreted as a high-order Yule-Walker (HOYW) method using a data based covariance matrix. The HOYW method is analysed at high SNR where closed-form expressions for the accuracy of the estimates are derived. By Monte Carlo simulations the HOYW method is applied to data consisting of one and two damped cisoids in additive white noise. The simulation results are compared with the results using the Kumaresan and Tufts method, with the Cramer-Rao bound, and with the derived theoretical results. The method is not statistically efficient, but the comparison shows that the HOYW method outperforms the method of Kumaresan and Tufts in terms of accuracy versus algorithmic complexity and in terms of precision in the cases considered. Due to the above properties the method is suitable to provide fast initial estimates for nonlinear search methods.

  • 91.
    Händel, Peter
    Institutionen för tekonologi, Uppsala universitet.
    Identifiering av dämpade sinussignaler i brus med en modifierad Yule-Walker metod1990In: REglermöte'90, Linköping, Sverige, 24-25 oktober, 1990, 1990Conference paper (Refereed)
  • 92.
    Händel, Peter
    Uppsala universitet.
    Indirekt skattning av parametervärden i energimodeller för byggnader1992In: Reglermöte'92, Göteborg, Sverige, 4-5 november, 1992, 1992Conference paper (Refereed)
  • 93.
    Händel, Peter
    KTH, Superseded Departments, Signals, Sensors and Systems.
    Markov-based single-tone frequency estimation1998In: IEEE transactions on circuits and systems. 2, Analog and digital signal processing (Print), ISSN 1057-7130, E-ISSN 1558-125X, Vol. 45, no 2, p. 230-232Article in journal (Refereed)
    Abstract [en]

    Markov-based single-tone frequency estimator is derived, and its properties are investigated. Its relation to other frequency es timators is studied, and it is shown that several commonly considered estimators follow as special cases.

  • 94.
    Händel, Peter
    Tampere University of Technology.
    On feedback predictive filtering of polynomial signals1997In: 1997 Finnish Signal Processing Symposium, May 22, 1997,Pori, Finland, 1997, p. 80-83Conference paper (Refereed)
    Abstract [en]

    Two different feedback structures derivedfrom a finite impulse response (FIR) predictor for polynomial signalsare considered.The resulting infinite impulseresponse predictors are studied withrespect to noise gain and step response.It is illustrated that  high order feedback structuresresult in superior performance compared tominimal order feedback structures.

  • 95.
    Händel, Peter
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    On noise reduction for enhancement of speech in mobile telephony applications2006In: Mathematical Modeling of Wave Phenomena / [ed] Nilsson, B. Fishman, L., 2006, Vol. 834, p. 369-376Conference paper (Refereed)
    Abstract [en]

    Noise reduction for mobile telephony applications is considered. A power spectral density error analysis is applied to the method of power subtraction. A minimum power spectral density error subtraction factor is derived, where the resulting factor depends on introduced quality factors. The outcome of the analysis is compared with experimental work as well as standardized noise reduction schemes.

  • 96. Händel, Peter
    On the performance of the weighted linear predictor frequency estimator1995In: IEEE Transactions on Signal Processing, ISSN 1053-587X, E-ISSN 1941-0476, Vol. 43, no 12, p. 3070-3071Article in journal (Refereed)
    Abstract [en]

    In a recent paper, a statistical analysis of Kay's weighted linear predictor frequency estimator was carried out. Here, using a different analysis technique to that employed in this same paper, the asymptotic variance of the weighted linear predictor frequency estimator is derived.

  • 97.
    Händel, Peter
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Parameter estimation employing a dual-channel sine-wave model under a Graussian assumption2008In: IEEE Transactions on Instrumentation and Measurement, ISSN 0018-9456, E-ISSN 1557-9662, Vol. 57, no 8, p. 1661-1669Article in journal (Refereed)
    Abstract [en]

    The Cramer-Rao bound (CRB) is a lower bound on the error variance of any estimator. For a Gaussian scenario, the CRB is derived for a seven-parameter, dual-channel sine-wave model, which is a model relevant to applications such as impedance measurements and the estimation of particle size and velocity by laser anemometry. Four different parameterizations; were considered: the common quadrature/in-phase and amplitude-phase models and two relative amplitude-phase models. The CRB indicated the achievable error variance of an unbiased estimator as a function of the signal-to-noise ratio (SNR), the number of samples, and noise power. A nonlinear least squares fit of the signal model to the collected data was employed. The problem at hand is separable and can be solved by a I-D search followed by a linear least squares fit of the remaining parameters. The performance of the method was investigated with the aid of a simulation study, and the outcome was compared with that of the corresponding CRB and with a recently proposed seven-parameter fit. For high SNRs, the performance of the proposed method is close to optimal with an error variance close to the predictions made by the CRB.

  • 98.
    Händel, Peter
    KTH, Superseded Departments, Signals, Sensors and Systems.
    Performance analysis of a constrained Yule-Walker frequency estimator1997In: IEICE Transactions on Fundamentals of Electronics Communications and Computer Sciences, ISSN 0916-8508, E-ISSN 1745-1337, Vol. E80A, no 12, p. 2600-2602Article in journal (Refereed)
    Abstract [en]

    The performance of a constrained (that is, minimal order) Yule-Walker (CYW) single tone frequency estimator is studied. A closed form expression for the asymptotic error variance is derived. It is shown that CYW does not satisfactorily utilize the information in data, and estimators with improved performance are proposed, Simulation results which lend support to the theoretical findings are included.

  • 99.
    Händel, Peter
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Power spectral density error analysis of spectral subtraction type of speech enhancement methods2007In: EURASTP journal an applied signal processing, ISSN 1110-8657, E-ISSN 1687-0433Article in journal (Refereed)
  • 100.
    Händel, Peter
    KTH, Superseded Departments, Signals, Sensors and Systems.
    Predictive digital filtering of sinusoidal signals1998In: IEEE Transactions on Signal Processing, ISSN 1053-587X, E-ISSN 1941-0476, Vol. 46, no 2, p. 364-374Article in journal (Refereed)
    Abstract [en]

    p-step ahead predictive filters for narrowband waveforms with rr, distinct spectral peaks are considered, By minimization of the noise gain, the coefficients of the optimal Lth order FIR predictor is derived, where L > 2m -1, The minimum-length FIR predictor is given by L = 2m -1, and the feedback extension of this predictor is studied. Design of feedback gains subject to different optimization criteria is studied in detail, The generalization to complex-valued signals, cascaded predictors, and adaptive predictors are also included, Several design and simulation examples are presented.

1234567 51 - 100 of 343
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • 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