Filtering device

US3949206A · kind A · utility

Assignee

• The United States of America as represented by the Administrator of the National Aeronautics and Space Administration · US

Inventors

• Thomas R. Edwards · Leawood, US
• Hugh W. Zeanah · Huntsville, US

Key dates

• Filing date: Dec 17, 1974
• Grant date: Apr 6, 1976
• Expiry date: Dec 17, 1994

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04B3/142
• WIPO field: Telecommunications
• WIPO sector: Electrical engineering

Abstract

An electrical filter for removing noise from a voice communications signal in which, for example, seven sample values of the signal are obtained continuously updated and subjected to filtering. Filtering is accomplished by adding balanced, with respect to a mid-point sample, spaced pairs of the sampled values and then multiplying each pair by a selected filter constant. The signal products thus obtained are summed to provide a filtered version of the original signal.