Rotationally predictive adaptive filter

Details Rotationally predictive adaptive filter Rotationally predictive adaptive filter

1997-07-03

1998-09-08

Ngo, Chuong Dinh

Boots, shoes, and leggings

3647242, 375232, G06F 1700

Patent

active

058054804

ABSTRACT:
A method for efficiently updating the coefficients of an adaptive equalizer in the situation of a propagation environment having a dynamically varying multipath. The invention is intended for use in the situation of a static direct path, dynamic multipath, and narrow band signal (bandwidth <<carrier frequency). The method of the present invention is based on the inventor's recognition of the cyclical (rotating) nature of the received signal arising from the effect of small changes in the dynamic multipath delay on a phase term which is part of the received signal. This led the inventor to conclude that the coefficients of the adaptive equalizer would exhibit a similar cyclical behavior. The cyclical behavior of the equalizer coefficients is incorporated into an LMS type coefficient update equation by multiplying the standard coefficient by a "predictive" functional term having a rotational behavior (e.g., e.sup.j.phi.). Update equations for the equalizer coefficients and the rotation term are then developed. As the behavior of the update equations stabilizes, the modified coefficient values converge to terms having a rotational phase behavior arising from the effect of the dynamic multipath delay factor, d(t). This causes the output of the equalizer to more closely approach that of the transmitted signals, enabling the adaptive equalizer to compensate for the effects of the dynamic multipath environment.

REFERENCES:
patent: 5084902 (1992-01-01), Aotani et al.
patent: 5414766 (1995-05-01), Cannalire et al.
patent: 5506871 (1996-04-01), Hwang et al.
patent: 5559839 (1996-09-01), Doelman
patent: 5590154 (1996-12-01), Forni et al.
Haykin, S., Adaptive Filtering Theory, Third Edition, pp. xiii-xiv; pp. 1-6; pp. 11-15; pp. 18-21; pp. 34-39; pp. 69-73; Chap. 9., "Least-Mean-Square Algorithm," pp. 365-369, Prentice-Hall, Inc., 1996.
Dorf, R. C. & Zhen Wan, "64.2 Equalization," The Electrical Engineering Handbook, pp. 1410-1416, CRC Press, Inc., 1993.
Gibson, J. D. & John G. Proakis, "Channel Equalization," Chap. 26, The Communications Handbook, pp. 339-363, CRC Press LLC, 1997.
Rappaport, T. S., "Equalization, Diversity, and Channel Coding," Chap. 6, Wireless Communications--Principles and Practice, pp. 299-324, Prentice Hall PTR, 1996.

Affiliated with

Also associated with

Rating

Rotationally predictive adaptive filter does not yet have a rating. At this time, there are no reviews or comments for this patent.

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

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1289443