Excitation vector generator, speech coder and speech decoder

• US 20050203736A1
• Filed: 05/11/2005
• Published: 09/15/2005
• Est. Priority Date: 11/07/1996
• Status: Active Grant

• Current Assignee: Godo Kaisha IP Bridge 1 (IP Bridge, Inc.)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Morii, Toshiyuki, Ehara, Hiroyuki, Yasunaga, Kazutoshi
• Granted Patent: US 7,587,316 B2
• Time in Patent Office: Days
• US Class Current: 704/226
• CPC Class Codes: G10L 19/12 the excitation function being a code excitation, e.g. in code excited linear prediction [CELP] vocoders
• CPC Class Codes: G10L 19/135 Vector sum excited linear prediction [VSELP]
• CPC Class Codes: G10L 2019/0007 Codebook element generation
• CPC Class Codes: G10L 2019/0013 Codebook search algorithms

Abstract

A noise canceller removes a noise component from an input speech signal. The noise canceller includes a noise cancellation coefficient adjuster that adjusts a noise cancellation coefficient to determine an amount of noise cancellation. A noise spectrum storage device stores an estimated noise spectrum. A noise estimator estimates a noise spectrum by comparing an input spectrum with a noise spectrum stored in the noise spectrum storage device. A noise canceling/spectrum compensator subtracts the noise spectrum stored in the noise spectrum storage device from the input spectrum based on a coefficient acquired by the noise cancellation coefficient adjuster.

Claims

1. A noise canceller for removing a noise component from an input speech signal, the noise canceller comprising:

a noise cancellation coefficient adjuster that adjusts a noise cancellation coefficient to determine an amount of noise cancellation;

a noise spectrum storage device that stores an estimated noise spectrum;

a noise estimator that estimates a noise spectrum by comparing an input spectrum with a noise spectrum stored in said noise spectrum storage device;

a noise canceling/spectrum compensator that subtracts said noise spectrum stored in said noise spectrum storage device from said input spectrum based on a coefficient acquired by said noise cancellation coefficient adjuster.