METHOD AND APPARATUS FOR DETECTING BAD DATA PACKETS RECEIVED BY A MOBILE TELEPHONE USING DECODED SPEECH PARAMETERS

• US 20080027710A1
• Filed: 01/12/2007
• Published: 01/31/2008
• Est. Priority Date: 09/25/1996
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Dejaco, Andrew, Jacobs, Paul
• Granted Patent: US 7,788,092 B2
• Time in Patent Office: Days
• US Class Current: 704/201
• CPC Class Codes: G10L 19/005 Correction of errors induced by the transmission channel, if related to the coding algorithm

Abstract

A speech signal is decoded by a vocoder and the reconstructed speech samples are provided to a decoded frame check unit. The decoded frame check unit examines the energy of the reconstructed speech and compares the energy of the reconstructed speech to a range of acceptable energy values. If the energy is not within the range of energy values, a frame erasure is declared and the decoded frame is prevented from being to the speaker in the telephone. In the exemplary implementation, the speech is reconstructed by a vocoder which includes a postfilter which in turn includes automatic gain control. The automatic gain control element of a post filter includes a means for measuring the energy of the decoded speech data. This measured energy is used by the decoded frame check unit to decide whether to provide the decoded data to the user or to declare a frame erasure. This implementation reduces the amount of additional hardware necessary to implement the present invention.

Claims

1. A speech signal receiving system comprising:

means for receiving an encoded speech signal;

means for decoding said encoded speech signal to provide a decoded speech signal;

means for determining a quality value for said decoded speech signal from an energy value of said decoded speech signal; and

means for muting an output of said system based upon said energy value.

2. The receiving system of claim 1 wherein said means for determining a quality value compares said energy value to a predetermined threshold and determines said quality value in accordance with said comparison.

3. The receiving system of claim 1 wherein said means for determining a quality value provides an erasure indication signal when said quality value indicates that said energy value exceeds an acceptable range.

4. The receiving system of claim 1 wherein said means for decoding comprises a post filter and wherein said postfilter is for calculating said energy value.

5. A method as described herein.

6. An apparatus as described herein.