Method for digital interpolation

US5717618A · kind A · utility

Assignee

• Deutsche ITT Industries, GmbH · DE

Inventors

• Andreas Menkhoff · Oberhaching, DE
• Miodrag Temerinac · Gundelfingen, DE
• Franz-Otto Witte · Landsberg am Lech, DE
• Martin Winterer · Gundelfingen, DE

Key dates

• Filing date: Jul 31, 1995
• Grant date: Feb 10, 1998
• Expiry date: Jul 31, 2015

Classification

• Technology area (CPC H): Electricity
• CPC primary: H03H17/0642
• WIPO field: Basic communication processes
• WIPO sector: Electrical engineering

Abstract

An improved method for digital interpolation of signals for a second interpolation filter is disclosed which permits a high signal/noise ratio with a minimum amount of circuitry for an overall system comprising first and second interpolation filters. The method for digital interpolation of signals requires multiplying delayed input values locked to a first signal by corresponding weighting factors which are dependent on a time-difference value determined by the interpolating instant and the time grid of the first clock signal. The weighting factors are determined by an impulse response in the time domain. The associated transfer function has an attenuation characteristic in the frequency domain which, with respect to the stop bands, is limited essentially to the alias regions located at the frequency multiples of the first clock signal. Each of these alias regions is assigned at least two adjacent zeros, or in the presence of double-order zeros, at least one of the alias regions and the associated periodic alias regions are assigned at least one further zero of the transfer function.