Digital speech processor using arbitrary excitation coding

Apparatus for encoding speech comprising

• means (330) for storing a set of signals each representative of a random code and set of index signals each identifying one of the random codes;
• means (203 through 247 except 225 and 245) for partitioning the speech into successive time frame interval portions and for forming a time-domain signal representative of the portion of speech in each successive time frame interval;
• means (225, 245, 250) for generating at least one transform domain signal from each such time-domain signal;
• means (305) responsive to each random code signal for generating a transform domain code signal corresponding thereto, via the same type of transformation as in the aforesaid means for generating a transform domain signal;
• means (315 and 320 or 501 through 520 and 320) for responding in a comparative fashion to transform domain signals for each time frame interval and, for each such signal, to each of said transform domain code signals to select one of the transform domain code signals as yielding minimum error or maximum similarity as a representative of the speech portion in the time frame interval;
• and
• means (325) for outputting the index signal corresponding to the random code signal corresponding to the selected transform domain code signal.

A method for encoding speech comprising the steps of

• storing a set of signals each representative of a random code and a set of index signals each identifying one of the random codes;
• partitioning the speech into successive time frame interval portions;
• forming a time-domain signal representative of the portion of speech in each successive time frame interval;
• generating at least one transform domain signal from each such time-domain signal;
• generating a transform domain code signal responsive to each random code signal, via the same type of transformation as in the aforesaid steps of generating a transform domain signal;
• cross-correlating transform domain signals for each time frame interval with each of said transform domain code signals to select one of the transform domain code signals as yielding minimum error or maximum similarly as a representative of the speech portion in the time-frame interval;
• and
• outputting the index signal corresponding to the random code signal corresponding to the selected transform domain code signal.

A method for encoding speech comprising

• storing a set of signals each representative of a random code and a set of index signals each identifying one of the random codes;
• partitioning the speech into successive time frame interval portions;
• forming a time-domain signal representative of the portion of speech in each successive time frame interval;
• generating at least one transform domain signal from each such time-domain signal;
• generating a transform domain code signal responsive to each random code signal via the same type of transformation as in the aforesaid step of generating a transform domain signal;
• responding in a comparative fashion to transform domain signals for each time frame interval and, for each such signal, to each of said transform domain code signals to select one of the transform domain code signals as yielding minimum error or maximum similarity as a representative of the speech portion in the time frame interval;
• and
• outputting the index signal corresponding to the random code signal corresponding to the selected transform.

Apparatus for providing a speech message comprising

• means for receiving a sequence of speech message signals for the successive time intervals of the speech message, each time interval speech message signal including a set of transform-domain-coded signals representative of the time interval portion of the speech message, at least a portion of which are index signals corresponding to a known set of random codes
• means for storing said known set of random codes in one-for-one association with the corresponding index signals
• means for generating said random codes for each of the set of index signals,
• and means for controlling speech wave generation for said time interval in response to said generated random codes.

A method for producing a speech message comprising

• receiving a sequence of speech message signals for the successive time intervals of the speech message, each time interval speech message signal including a set of transform-domain-coded signals representative of the time interval portion of the speech message, at least a portion of which are index signals corresponding to a known set of random codes;
• storing said known set of random codes in one-for-one association with the corresponding index signals;
• generating said codes sequentially for each of the set of index signals;
• and controlling speech wave generation for said time interval in response to said sequentially generated random codes.

Apparatus for processing input speech signals occurring over one or more successive time frame intervals comprising

• means (e.g., 203, 205) for forming first signals representative of said speech signals for each of said time frame intervals,
• means (e.g., 305) for providing a set of transform domain representations of a corresponding set of codes each of said codes being representative of possible speech signals over a time frame interval, and for providing a set of index signals, each identifying one of said codes,
• means (e.g., 315) for generating a set of similarity signals corresponding to the similarity of said first signals to each of said set of transform domain representations,
• means (e.g., 320) for generating index signals corresponding to codes having transform domain representations giving rise to similarity signals meeting a predetermined criterion.

The method of processing input speech signals occurring over one or more successive time frame intervals comprising

• forming first signals representative of said speech signals for each of said time frame intervals,
• providing a set of transform domain representations of a corresponding set of codes each of said codes being representative of possible speech signals over a time frame interval, and for providing a set of index signals, each identifying one of said codes,
• generating a set of similarity signals corresponding to the similarity of said first signals to each of said set of transform domain representations,
• generating index signals corresponding to codes having transform domain representations giving rise to similarity signals meeting a predetermined
• criterion.