The Experts below are selected from a list of 28998 Experts worldwide ranked by ideXlab platform
Jesper Jensen - One of the best experts on this subject based on the ideXlab platform.
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ICASSP - Analysis of closed-loop acoustic feedback cancellation systems
2013 IEEE International Conference on Acoustics Speech and Signal Processing, 2013Co-Authors: Meng Guo, Soren Holdt Jensen, Jesper Jensen, Steven L. GrantAbstract:In a previous study, the performance of an acoustic feedback/echo cancellation system was analyzed using a Power Transfer Function method. Whereas the analysis result provides very accurate performance predictions in open-loop acoustic echo cancellation systems, it is less accurate in closed-loop acoustic feedback cancellation systems if there is a strong correlation between the loudspeaker signal and the signals entering the microphones. This work extends the performance analysis to include the effects of the nonzero correlation on the adaptive filters. Simulation results verify that this extension provides much more accurate performance predictions in closed-loop acoustic feedback cancellation systems.
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analysis of acoustic feedback echo cancellation in multiple microphone and single loudspeaker systems using a Power Transfer Function method
IEEE Transactions on Signal Processing, 2011Co-Authors: Thomas Bo Elmedyb, Soren Holdt Jensen, Jesper JensenAbstract:In this work, we analyze a general multiple-microphone and single-loudspeaker audio processing system, where a multichannel adaptive system is used to cancel the effect of acoustic feedback/echo, and a beamformer processes the feedback/echo canceled signals. We introduce and derive an accurate approximation of a frequency domain measure - the Power Transfer Function - and show how it can be used to predict the convergence rate, system stability bound and the steady-state behavior of the entire cancellation system across frequency and time. We consider three example adaptive algorithms in the cancellation system: the least mean square, normalized least mean square, and the recursive least squares algorithms. Furthermore, we derive expressions to determine the step size parameter in the adaptive algorithms to achieve a desired system behavior, e.g., convergence rate at a specific frequency. Finally, we compare and discuss the performance of all three adaptive algorithms, and we verify the derived expressions through simulation experiments.
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EUSIPCO - Comparison of multiple-microphone and single-loudspeaker adaptive feedback/echo cancellation systems
2011Co-Authors: Meng Guo, Thomas Bo Elmedyb, Soren Holdt Jensen, Jesper JensenAbstract:Recently, we introduced a frequency domain measure - the Power Transfer Function - to predict the convergence rate, system stability bound and the steady-state behavior across time and frequency of a least mean square based feedback/echo cancellation algorithm in a general multiple-microphone and single-loudspeaker system. In this work, we extend the theoretical analysis to the normalized least mean square and recursive least squares algorithms. Furthermore, we compare and discuss the system behaviors in terms of the Power Transfer Function for all three adaptive algorithms.
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Analysis of Acoustic Feedback/Echo Cancellation in Multiple-Microphone and Single-Loudspeaker Systems Using a Power Transfer Function Method
IEEE Transactions on Signal Processing, 2011Co-Authors: Thomas Bo Elmedyb, Soren Holdt Jensen, Jesper JensenAbstract:In this work, we analyze a general multiple-microphone and single-loudspeaker audio processing system, where a multichannel adaptive system is used to cancel the effect of acoustic feedback/echo, and a beamformer processes the feedback/echo canceled signals. We introduce and derive an accurate approximation of a frequency domain measure - the Power Transfer Function - and show how it can be used to predict the convergence rate, system stability bound and the steady-state behavior of the entire cancellation system across frequency and time. We consider three example adaptive algorithms in the cancellation system: the least mean square, normalized least mean square, and the recursive least squares algorithms. Furthermore, we derive expressions to determine the step size parameter in the adaptive algorithms to achieve a desired system behavior, e.g., convergence rate at a specific frequency. Finally, we compare and discuss the performance of all three adaptive algorithms, and we verify the derived expressions through simulation experiments.
B. J. Eggleton - One of the best experts on this subject based on the ideXlab platform.
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Slow-light enhanced nonlinear Transfer Function for 2R regeneration in 2D silicon photonic crystals at 10 Gb/s
2009 IEEE LEOS Annual Meeting Conference Proceedings, 2009Co-Authors: B. Corcoran, C. Monat, D. Pudo, M. Pelusi, T. P. White, L. O'faolain, T. F. Krauss, B. J. Eggleton, D. J. MossAbstract:We report a nonlinear Power Transfer Function generated through slow-light enhanced nonlinear absorption in silicon photonic crystal waveguides. Pulse regeneration and error reduction in a 10 Gb/s pseudo-random bit signal are observed.
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Nonlinear Transfer Function in slow light silicon photonic crystal waveguides at 10 Gbit/s
Conference on Lasers and Electro-Optics International Quantum Electronics Conference, 2009Co-Authors: D. Pudo, B. Corcoran, C. Monat, M. Pelusi, T. P. White, L. O'faolain, B. J. Eggleton, D. J. Moss, T. F. KraussAbstract:We investigate the nonlinear Power Transfer Function generated through slow-light enhanced nonlinear absorption in silicon photonic crystal waveguides. Pulse regeneration and error reduction in a 10 Gbit/s data signal are observed for 10MHz amplitude distortion.
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All-optical regeneration based on a nonlinear long period grating
Optics Communications, 2008Co-Authors: Thomas Grujic, H.c. Nguyen, Michael R. E. Lamont, C. Martijn De Sterke, B. J. EggletonAbstract:We theoretically investigate a nonlinear all-optical switching scheme based on a long period grating written in a highly nonlinear chalcogenide fiber. We investigate the impact of two-photon absorption on the device and show that the influence of a modest amount of two photon absorption is actually beneficial to device performance as quantified by the Power Transfer Function and improvement of the Q-factor of an incident signal.
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All-optical in-band OSNR monitoring at 160Gb/s using non-linear optical loop mirror
COIN-ACOFT 2007 - Joint International Conference on the Optical Internet and the 32nd Australian Conference on Optical Fibre Technology, 2007Co-Authors: Tim Iredale, M. Pelusi, B. J. EggletonAbstract:A sensitive optical signal-to-noise ratio (OSNR) monitor was implemented at 160Gb/s using the non-linear Power Transfer Function (PTF) of an asymmetrical non-linear optical loop mirror (NOLM). The device is highly sensitive in the region 5-15dB OSNR.
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2R optical regenerator in As2Se3 chalcogenide fiber characterized by a frequency-resolved optical gating analysis.
Applied Optics, 2006Co-Authors: Michael R. E. Lamont, Martin Rochette, D. J. Moss, B. J. EggletonAbstract:We present a detailed analysis of a 2R optical regenerator based on self-phase modulation in As(2)Se(3) chalcogenide glass fiber using frequency-resolved optical gating (FROG). We obtain good agreement between the FROG measurements and theory, and confirm that the output pulses are near-transform limited. We show that two-photon absorption improves the profile of the Power Transfer Function while not degrading the temporal performance.
Thomas Bo Elmedyb - One of the best experts on this subject based on the ideXlab platform.
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analysis of acoustic feedback echo cancellation in multiple microphone and single loudspeaker systems using a Power Transfer Function method
IEEE Transactions on Signal Processing, 2011Co-Authors: Thomas Bo Elmedyb, Soren Holdt Jensen, Jesper JensenAbstract:In this work, we analyze a general multiple-microphone and single-loudspeaker audio processing system, where a multichannel adaptive system is used to cancel the effect of acoustic feedback/echo, and a beamformer processes the feedback/echo canceled signals. We introduce and derive an accurate approximation of a frequency domain measure - the Power Transfer Function - and show how it can be used to predict the convergence rate, system stability bound and the steady-state behavior of the entire cancellation system across frequency and time. We consider three example adaptive algorithms in the cancellation system: the least mean square, normalized least mean square, and the recursive least squares algorithms. Furthermore, we derive expressions to determine the step size parameter in the adaptive algorithms to achieve a desired system behavior, e.g., convergence rate at a specific frequency. Finally, we compare and discuss the performance of all three adaptive algorithms, and we verify the derived expressions through simulation experiments.
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EUSIPCO - Comparison of multiple-microphone and single-loudspeaker adaptive feedback/echo cancellation systems
2011Co-Authors: Meng Guo, Thomas Bo Elmedyb, Soren Holdt Jensen, Jesper JensenAbstract:Recently, we introduced a frequency domain measure - the Power Transfer Function - to predict the convergence rate, system stability bound and the steady-state behavior across time and frequency of a least mean square based feedback/echo cancellation algorithm in a general multiple-microphone and single-loudspeaker system. In this work, we extend the theoretical analysis to the normalized least mean square and recursive least squares algorithms. Furthermore, we compare and discuss the system behaviors in terms of the Power Transfer Function for all three adaptive algorithms.
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Analysis of Acoustic Feedback/Echo Cancellation in Multiple-Microphone and Single-Loudspeaker Systems Using a Power Transfer Function Method
IEEE Transactions on Signal Processing, 2011Co-Authors: Thomas Bo Elmedyb, Soren Holdt Jensen, Jesper JensenAbstract:In this work, we analyze a general multiple-microphone and single-loudspeaker audio processing system, where a multichannel adaptive system is used to cancel the effect of acoustic feedback/echo, and a beamformer processes the feedback/echo canceled signals. We introduce and derive an accurate approximation of a frequency domain measure - the Power Transfer Function - and show how it can be used to predict the convergence rate, system stability bound and the steady-state behavior of the entire cancellation system across frequency and time. We consider three example adaptive algorithms in the cancellation system: the least mean square, normalized least mean square, and the recursive least squares algorithms. Furthermore, we derive expressions to determine the step size parameter in the adaptive algorithms to achieve a desired system behavior, e.g., convergence rate at a specific frequency. Finally, we compare and discuss the performance of all three adaptive algorithms, and we verify the derived expressions through simulation experiments.
D. J. Moss - One of the best experts on this subject based on the ideXlab platform.
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Slow-light enhanced nonlinear Transfer Function for 2R regeneration in 2D silicon photonic crystals at 10 Gb/s
2009 IEEE LEOS Annual Meeting Conference Proceedings, 2009Co-Authors: B. Corcoran, C. Monat, D. Pudo, M. Pelusi, T. P. White, L. O'faolain, T. F. Krauss, B. J. Eggleton, D. J. MossAbstract:We report a nonlinear Power Transfer Function generated through slow-light enhanced nonlinear absorption in silicon photonic crystal waveguides. Pulse regeneration and error reduction in a 10 Gb/s pseudo-random bit signal are observed.
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Nonlinear Transfer Function in slow light silicon photonic crystal waveguides at 10 Gbit/s
Conference on Lasers and Electro-Optics International Quantum Electronics Conference, 2009Co-Authors: D. Pudo, B. Corcoran, C. Monat, M. Pelusi, T. P. White, L. O'faolain, B. J. Eggleton, D. J. Moss, T. F. KraussAbstract:We investigate the nonlinear Power Transfer Function generated through slow-light enhanced nonlinear absorption in silicon photonic crystal waveguides. Pulse regeneration and error reduction in a 10 Gbit/s data signal are observed for 10MHz amplitude distortion.
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2R optical regenerator in As2Se3 chalcogenide fiber characterized by a frequency-resolved optical gating analysis.
Applied Optics, 2006Co-Authors: Michael R. E. Lamont, Martin Rochette, D. J. Moss, B. J. EggletonAbstract:We present a detailed analysis of a 2R optical regenerator based on self-phase modulation in As(2)Se(3) chalcogenide glass fiber using frequency-resolved optical gating (FROG). We obtain good agreement between the FROG measurements and theory, and confirm that the output pulses are near-transform limited. We show that two-photon absorption improves the profile of the Power Transfer Function while not degrading the temporal performance.
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investigation of self phase modulation based optical regeneration in single mode as2se3 chalcogenide glass fiber
Optics Express, 2005Co-Authors: Libin Fu, Martin Rochette, D. J. Moss, V G Taeed, B. J. EggletonAbstract:We investigate the feasibility of all-optical regeneration based on self-phase modulation in single mode As2Se3 chalcogenide fiber. By combining the chalcogenide fiber with a bandpass filter, we achieve a near step-like Power Transfer Function with no pulse distortion. The device is shown to operate with 5.8 ps duration pulses, thus demonstrating the feasibility of this device operating with high bit-rate data signals. These results are achieved with pulse peak Powers <10 W in a fully passive device, including only 2.8 m of chalcogenide fiber. We obtain an excellent agreement between theory and experiment and show that both the high nonlinearity of the chalcogenide glass along with its high normal dispersion near 1550 nm enables a significant device length reduction in comparison with silica-based devices, without compromise on the performance. We find that even for only a few meters of fiber, the large normal dispersion of the chalcogenide glass inhibits spectral oscillations that would appear with self-phase modulation alone. We measure the two photon absorption attenuation coefficient and find that it advantageously affects the device Transfer Function.
Soren Holdt Jensen - One of the best experts on this subject based on the ideXlab platform.
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ICASSP - Analysis of closed-loop acoustic feedback cancellation systems
2013 IEEE International Conference on Acoustics Speech and Signal Processing, 2013Co-Authors: Meng Guo, Soren Holdt Jensen, Jesper Jensen, Steven L. GrantAbstract:In a previous study, the performance of an acoustic feedback/echo cancellation system was analyzed using a Power Transfer Function method. Whereas the analysis result provides very accurate performance predictions in open-loop acoustic echo cancellation systems, it is less accurate in closed-loop acoustic feedback cancellation systems if there is a strong correlation between the loudspeaker signal and the signals entering the microphones. This work extends the performance analysis to include the effects of the nonzero correlation on the adaptive filters. Simulation results verify that this extension provides much more accurate performance predictions in closed-loop acoustic feedback cancellation systems.
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analysis of acoustic feedback echo cancellation in multiple microphone and single loudspeaker systems using a Power Transfer Function method
IEEE Transactions on Signal Processing, 2011Co-Authors: Thomas Bo Elmedyb, Soren Holdt Jensen, Jesper JensenAbstract:In this work, we analyze a general multiple-microphone and single-loudspeaker audio processing system, where a multichannel adaptive system is used to cancel the effect of acoustic feedback/echo, and a beamformer processes the feedback/echo canceled signals. We introduce and derive an accurate approximation of a frequency domain measure - the Power Transfer Function - and show how it can be used to predict the convergence rate, system stability bound and the steady-state behavior of the entire cancellation system across frequency and time. We consider three example adaptive algorithms in the cancellation system: the least mean square, normalized least mean square, and the recursive least squares algorithms. Furthermore, we derive expressions to determine the step size parameter in the adaptive algorithms to achieve a desired system behavior, e.g., convergence rate at a specific frequency. Finally, we compare and discuss the performance of all three adaptive algorithms, and we verify the derived expressions through simulation experiments.
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EUSIPCO - Comparison of multiple-microphone and single-loudspeaker adaptive feedback/echo cancellation systems
2011Co-Authors: Meng Guo, Thomas Bo Elmedyb, Soren Holdt Jensen, Jesper JensenAbstract:Recently, we introduced a frequency domain measure - the Power Transfer Function - to predict the convergence rate, system stability bound and the steady-state behavior across time and frequency of a least mean square based feedback/echo cancellation algorithm in a general multiple-microphone and single-loudspeaker system. In this work, we extend the theoretical analysis to the normalized least mean square and recursive least squares algorithms. Furthermore, we compare and discuss the system behaviors in terms of the Power Transfer Function for all three adaptive algorithms.
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Analysis of Acoustic Feedback/Echo Cancellation in Multiple-Microphone and Single-Loudspeaker Systems Using a Power Transfer Function Method
IEEE Transactions on Signal Processing, 2011Co-Authors: Thomas Bo Elmedyb, Soren Holdt Jensen, Jesper JensenAbstract:In this work, we analyze a general multiple-microphone and single-loudspeaker audio processing system, where a multichannel adaptive system is used to cancel the effect of acoustic feedback/echo, and a beamformer processes the feedback/echo canceled signals. We introduce and derive an accurate approximation of a frequency domain measure - the Power Transfer Function - and show how it can be used to predict the convergence rate, system stability bound and the steady-state behavior of the entire cancellation system across frequency and time. We consider three example adaptive algorithms in the cancellation system: the least mean square, normalized least mean square, and the recursive least squares algorithms. Furthermore, we derive expressions to determine the step size parameter in the adaptive algorithms to achieve a desired system behavior, e.g., convergence rate at a specific frequency. Finally, we compare and discuss the performance of all three adaptive algorithms, and we verify the derived expressions through simulation experiments.