Tuned feedforward LMS filter with feedback control

Details Tuned feedforward LMS filter with feedback control Tuned feedforward LMS filter with feedback control

2006-02-07

2006-02-07

Grier, Laura A. (Department: 2644)

Electrical audio signal processing systems and devices

Acoustical noise or sound cancellation

Counterwave generation control path

C381S071120, C381S071100, C381S071600

Reexamination Certificate

active

06996241

ABSTRACT:
A method to automatically and adaptively tune a leaky, normalized least-mean-square (LNLMS) algorithm so as to maximize the stability and noise reduction performance in feedforward adaptive noise cancellation systems. The automatic tuning method provides for time-varying tuning parameters λkand μkthat are functions of the instantaneous measured acoustic noise signal, weight vector length, and measurement noise variance. The method addresses situations in which signal-to-noise ratio varies substantially due to nonstationary noise fields, affecting stability, convergence, and steady-state noise cancellation performance of LMS algorithms. The method has been embodied in the particular context of active noise cancellation in communication headsets. However, the method is generic, in that it is applicable to a wide range of systems subject to nonstationary, i.e., time-varying, noise fields, including sonar, radar, echo cancellation, and telephony. Further, the hybridization of the disclosed Lyapunov-tuned feedforward LMS filter with a feedback controller as also disclosed herein enhances stability margins, robustness, and further enhances performance.

REFERENCES:
patent: 6396930 (2002-05-01), Vaudrey et al.
patent: 6741707 (2004-05-01), Ray et al.
Rafaely and Jones, “Combined feedback-feedforward active noise-reducing headset—The effect of the acoustic on broadband performance,” Sep. 2002, 112, pp. 981-989,Journal of Acoustical Society of America, Southampton, United Kingdom.
Streeter, Ray, and Collier, “Hybrid Feedforward-Feedback Active Noise Control,” Thayer School of Engineering, Dartmouth College, Hanover, NH, USA.
Winberg, Johansson, Lagö, and Claesson, “A New Passive/Active Hybrid Headset for a Helicopter Application,” 1999, vol. 4, No. 2, pp. 51-58,International Journal of Acoustics and Vibration, University of Karlskrona/Ronneby, Department of Signal Processing, Ronneby, Sweden.
Gitlin, Meadors, Jr., and Weinstein, “The Tap-Leakage Algorithm: An Algorithm for the Stable Operation of a Digitally Implemented, Fractionally Spaced Adaptive Equalizer,” Oct. 1982, vol. 61, pp. 1817-1839,The Bell System Technical Journal, New Jersey, USA.
Mayyas and Aboulnasr, “Leaky LMS Algorithm: MSE Analysis for Gaussian Data,” Apr., 1997, vol. 45, No. 4, pp. 927-934,IEEE Transactions on Signal Processing.
Nascimento and Sayed, “Unbiased and Stable Leakage-Based Adaptive Filters,” Dec., 1999, vol. 47, No. 12, pp. 3261-3275,IEEE Transactions on Signal Processing.
Nascimento and Sayed, “An Unbiased and Cost-Effective Leaky-LMS Filter,” 1997, 1078-1082, University of California, Los Angeles, CA, USA.
Gelfand, Wei and Krogmeier, “The Stability of Variable Step-Size LMS Algorithms,” Dec., 1999, vol. 47, No. 12, pp. 3277-3288.
Ryan, Shaw, Brammer and Zhang, “Enclosure for Low-Frequency Assessment of Active Noise Reducing Circumaural Headsets and Hearing Protectors,” 1993, pp. 19-20,Canadian Acoustics, Ottawa, Ontario, Canada.
Brammer and Pan, “Opportunities for Active Noise Control in Communication Headsets,” Sep. 1998, vol. 26, No. 3, pp. 32-33,Canadian Acoustics, Ottawa, Ontario, Canada.
Crabtree, “Real-World Performance of Headset Active Noise Reduction Systems,” ASA Special Session 3aSP: Performance of Active Noise Control Systems in Real-World Applications, Oct. 1998, pp. 1-14, Norfolk, VA, ISA.
Pan, Brammer, Goubran, Ryan and Zeral, “Broad-Band Active Noise Reduction in Communication Headsets,” Mar. 1994 vol. 22, No. 3, pp. 113-114,Canadian Acoustics.
Cartes, Ray and Collier, “Experimental evaluation of leaky least-mean-square algorithms for active noise reduction in communication headsets,” Apr. 2002, vol. 111, No. 4, pp. 1758-1771,J. Acoustic Society of America.
Cartes, “Lyapunov Tuning and Optimization of Feedforward Noise Reduction for Single-Point, Single-Source Cancellation,” Oct. 2000, pp. 1-193, Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire, USA.
Ward, “Effects of High-Intensity Sound”, 1997, pp. 1497-1507.

Affiliated with

Also associated with

Rating

Tuned feedforward LMS filter with feedback control does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Tuned feedforward LMS filter with feedback control, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Tuned feedforward LMS filter with feedback control will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3676721