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:
Jan. 17, 1984
Filed:
Mar. 05, 1981
Charles W Gritton, North Brunswick, NJ (US);
Bell Telephone Laboratories, Incorporated, Murray Hill, NJ (US);
Abstract
Energy in a received signal is distinguished as being whole band energy or partial band energy by comparing an average value of the received signal to a modified magnitude value of the received signal. A signal representative of the comparison result is supplied to a filter including hysteresis for generating a signal to control representative of whether whole band or partial band energy is present. Hysteresis is provided in generation of the control signal by comparing the output amplitude of the filter to a first threshold value when the control signal is a first state and then comparing the filter output amplitude to a second lower threshold value when the control signal is a second state. When the modified magnitude value exceeds the average value, the received signal includes whole band energy, otherwise the received signal includes only partial band energy. In one example, this technique is employed in an echo canceler to enable updating an echo path estimate during intervals that the received signal includes whole band energy and to inhibit updating of the echo estimate being generating when the received signal includes only partial band energy.