Method and apparatus for generating encoded speech signals

• US 20060259296A1
• Filed: 07/20/2006
• Published: 11/16/2006
• Est. Priority Date: 12/14/1993
• Status: Active Grant

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Lin, Daniel
• Granted Patent: US 7,444,283 B2
• Time in Patent Office: Days
• US Class Current: 704/219
• 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 2019/0005 Multi-stage vector quantisation
• CPC Class Codes: G10L 2019/0007 Codebook element generation

Abstract

A method for processing speech in a spread spectrum communication system uses CELP speech encoded signals. A speech input receives samples of a speech signal and a codebook analysis block for selects an index of a code from each of a plurality of codebooks. A weighted synthesis filter is used in the generation of a prediction error between a predicted current sample and a current sample of the speech samples. The index is transmitted to the receiver to enable reconstruction of the speech signal at the receiver.

Claims

1. A method of generating encoded speech signals, the method comprising:

sampling a speech signal;

generating a first signal including code index and gain based on samples of the speech signal;

generating a second signal including pitch lag and gain based on samples of the speech signal;

generating a third signal including a line spectral pair (LSP) index based on samples of the speech signal; and

digitally multiplexing the first, second and third signals on a communication channel.

2. The method of claim 1 wherein the third signal is generated by performing LPC analysis and quantizing the result of the LPC analysis.

3. The method of claim 1 wherein the second signal is generated by performing adaptive codebook analysis on weighted samples of the speech signal.

4. The method of claim 1 wherein the first signal is generated by performing ternary codebook analysis on weighted samples of the speech signal.

5. A speech encoder comprising:

means for sampling a speech signal;

means for generating a first signal including code index and gain based on samples of the speech signal;

means for generating a second signal including pitch lag and gain based on samples of the speech signal;

means for generating a third signal including a line spectral pair (LSP) index based on samples of the speech signal; and

a transmitter for digitally multiplexing the first, second and third signals on a communication channel.

6. The speech encoder of claim 5 wherein the third signal is generated by performing LPC analysis and quantizing the result of the LPC analysis.

7. The speech encoder of claim 5 wherein the second signal is generated by performing adaptive codebook analysis on weighted samples of the speech signal.

8. The speech encoder of claim 5 wherein the first signal is generated by performing ternary codebook analysis on weighted samples of the speech signal.