System of encoding and decoding speech signals

A variable rate speech compression system for processing a speech signal, the variable rate speech compression system comprising:

• a first codec operable to encode and decode a first frame of the speech signal, the first codec activated as a function of a selected bit rate, the first codec operable to encode and decode as a function of a type classification, the type classification comprising one of a first type and a second type;
• and
• a second codec operable to encode and decode a second frame of the speech signal, the second codec activated as a function of a selected bit rate to encode and decode the second frame regardless of the type classification;
• where the first codec is operable to encode an adaptive codebook gain and a fixed codebook gain when the first rate is selected and the type classification is the second type, and where the adaptive codebook gain is encoded exclusive of the fixed codebook gain.

A variable rate speech compression system for processing a speech signal, the variable rate speech compression system comprising:

• an encoding system operable to extract and encode parameters of a frame of the speech signal, the encoding system comprising:
• a frame processing module operable to encode parameters representative of the frame as a function of a rate selection comprising one of a first rate and a second rate and a type classification comprising one of a first type and a second type, the frame processing module comprising a pitch pre-processing module operable to modify the speech signal to improve encoding;
• and
• a subframe processing module operable to encode parameters representative of a subframe of the frame as a function of the rate selection and the type classification;
• where the pitch pre-processing module is operable to modify the speech signal as a function of a grade characterization of the speech signal.

A variable rate speech compression system for processing a speech signal, the variable rate speech compression system comprising:

• an encoding system operable to extract and encode parameters of a frame of the speech signal, the encoding system comprising:
• a frame processing module operable to encode parameters representative of the frame as a function of a rate selection comprising one of a first rate and a second rate and a type classification comprising one of a first type and a second type, the frame processing module comprising a pitch pre-processing module operable to modify the speech signal to improve encoding;
• and
• a subframe processing module operable to encode parameters representative of a subframe of the frame as a function of the rate selection and the type classification;
• where the subframe processing module is operable to search a fixed codebook to determine a fixed codebook contribution for the subframe, when the rate selection is the first rate, and the type classification is the first type;
• where the fixed codebook comprises three 5-pulse codebooks.

A variable rate speech compression system for processing a speech signal, the variable rate speech compression system comprising:

• an encoding system operable to extract and encode parameters of a frame of the speech signal, the encoding system comprising:
• a frame processing module operable to encode parameters representative of the frame as a function of a rate selection comprising one of a first rate and a second rate and a type classification comprising one of a first type and a second type, the frame processing module comprising a pitch pre-processing module operable to modify the speech signal to improve encoding;
• and
• a subframe processing module operable to encode parameters representative of a subframe of the frame as a function of the rate selection and the type classification;
• where the subframe processing module is operable to search a fixed codebook to determine a fixed codebook contribution for the subframe, when the rate selection is the first rate, and the type classification is the second type;
• where the fixed codebook comprises an 8-pulse codebook.

A variable rate speech compression system for processing a speech signal, the variable rate speech compression system comprising:

• an encoding system operable to extract and encode parameters of a frame of the speech signal, the encoding system comprising:
• a frame processing module operable to encode parameters representative of the frame as a function of a rate selection comprising one of a first rate and a second rate and a type classification comprising one of a first type and a second type, the frame processing module comprising a pitch pre-processing module operable to modify the speech signal to improve encoding;
• and
• a subframe processing module operable to encode parameters representative of a subframe of the frame as a function of the rate selection and the type classification;
• where the subframe processing module is operable to search a fixed codebook to determine a fixed codebook contribution for the subframe, when the rate selection is the second rate, and the type classification is the first type;
• the fixed codebook comprising a 2-pulse codebook, a 3-pulse codebook and a Gaussian codebook.

A variable rate speech compression system for processing a speech signal, the variable rate speech compression system comprising:

• an encoding system operable to extract and encode parameters of a frame of the speech signal, the encoding system comprising:
• a frame processing module operable to encode parameters representative of the frame as a function of a rate selection comprising one of a first rate and a second rate and a type classification comprising one of a first type and a second type, the frame processing module comprising a pitch pre-processing module operable to modify the speech signal to improve encoding;
• and
• a subframe processing module operable to encode parameters representative of a subframe of the frame as a function of the rate selection and the type classification;
• where the subframe processing module is operable to search a fixed codebook to determine a fixed codebook contribution for the subframe, when the rate selection is the second rate, and the type classification is the second type;
• where the fixed codebook comprises a 2-pulse codebook and a 3-pulse codebook.

A system for processing a frame of a speech signal, the system comprising:

• a first codec selectively activated as a function of a rate selected for the frame, the first codec comprising:
• a plurality of frame processing modules operable to encode parameters representative of the frame as a function of a type classification of the frame to form a first portion of an encoded speech signal;
• and
• a plurality of subframe processing modules operable to encode parameters representative of each of a plurality of subframes of the frame as a function of the type classification to form a second portion of the encoded speech signal;
• and
• a second codec selectively activated as a function of the rate selected for the frame, the second codec comprising:
• an initial frame-processing module operable to encode parameters representative of the frame regardless of the type classification;
• and
• a rate module operable to encode parameters of the frame regardless of the type classification;
• where the first codec is operable to encode an adaptive codebook gain and a fixed codebook gain as a function of the rate and the type classification, and where the adaptive codebook gain is encoded exclusive of the fixed codebook gain.

A method of processing a speech signal with a speech compression system, the method comprising:

• a) extracting parameters from a frame of the speech signal;
• b) selecting from one of a first rate selection and a second rate selection as a function of the parameters extracted from the frame;
• c) selecting a type classification as a function of the parameters extracted from the frame when the first rate selection is selected;
• d) encoding the frame as a function of the first rate selection and the type classification when the first rate selection is selected;
• and
• e) encoding the frame as a function of the second rate selection, regardless of the type classification, when the second rate selection is selected;
• where b) comprises characterizing the frame as a function of the parameters., and where the characterizing the frame comprises:
• performing an initial characterization, and performing a final characterization.

A method of processing a speech signal, the method comprising:

• a) extracting parameters from a frame of the speech signal;
• b) selecting a bit rate as a function of the extracted parameters;
• c) selecting a type classification as a function of the extracted parameters;
• d) encoding extracted parameters representative of the frame as a function of the bit rate and the type classification;
• and
• e) encoding extracted parameters representative of each of a plurality of subframes of the frame as a function of the bit rate and the type classification;
• where e) comprises encoding a fixed codebook contribution when the type classification is type one, and where encoding the fixed codebook contribution comprises searching an 8-pulse codebook when the bit rate selected is a full rate.

A method of processing a speech signal, the method comprising:

• a) extracting parameters from a frame of the speech signal;
• b) selecting a bit rate as a function of the extracted parameters;
• c) selecting a type classification as a function of the extracted parameters;
• d) encoding extracted parameters representative of the frame as a function of the bit rate and the type classification;
• and
• e) encoding extracted parameters representative of each of a plurality of subframes of the frame as a function of the bit rate and the type classification;
• where e) comprises encoding a fixed codebook contribution when the type classification is type one, and where encoding the fixed codebook contribution comprises searching a 2-pulse codebook and a 3-pulse codebook when the bit rate selected is a half rate.