The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 02, 1999
Filed:
Jan. 29, 1998
Shigeji Ikeda, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A noise canceler of the present invention includes a signal-to-noise power ratio estimator to which a main signal and a reference signal are input. The estimator 10 estimates the sinal-to-noise power ratio of the main signal from the mean power of a desired signal contained in the main siganl and a mean power of a noise signal also contained in the main signal. In addition, the estimator estimates the signal-to-noise power ratio of the reference signal from the mean power of a desired signal contained in the reference signal and the mean power of a noise singal also contained in the reference signal. An adptive filter for estimating the noise signal of the main signal has its step size for coefficient updating controlled in accordance with the estimated signal-to-noise power ratio of the noise signal. On the other hand, an adptive filter for estimating the desired signal of the reference signal has its step size for coefficient updating controlled in accordance with the estimated signal-to-noise power ratio of the reference signal. Delay circuits are provided for compensating for a delay ascribable to a power averaging procedure which a signal-to-noise power ratio estimator executes to calculate the estimated siganl-to-noise power ratios.