Measuring mis-match between signals

US4471453A · kind A · utility

Assignee

• U.S. Philips Corporation · US

Inventors

• Hermann Ney · Hamburg, DE
• Rudolf Geppert · Hamburg, DE

Key dates

• Filing date: Sep 21, 1981
• Grant date: Sep 11, 1984
• Expiry date: Sep 21, 2001

Classification

• Technology area (CPC G): Physics
• CPC primary: G10L15/00
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

The degree of mis-match which would be obtained between a test and a reference signal, for example speech signals, should their time-axes be subjected to that relative shift and/or distortion which is required to minimize the degree of mismatch is carried out by sampling the two signals at regular intervals and storing these samples in memories. All the samples of one signal are then read out in succession from one memory; each successive sample of the other signal is read out from the other memory, and the difference between each pair of samples is formed in a subtractor. Each difference value from the subtractor is added to the smallest of three quantities, X, Y and Z and the result stored in a register to form the new quantity X. This new quantity X is also stored in a further memory cyclically addressed in tandem with the memory 12. The quantity Z is the previous content of the location of memory into which the new quantity X is written, and the quantity Y is the previous value of the quantity Z, obtained by shifting the previous value of the quantity Z in a two-stage shift register. Thus the quantities X, Y and Z correspond to the present sample of the other signal and the imm…