EP0557940A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Speech coding system
Assignee: NEC Corp
•
Filing: 1993-02-23
•
Granted: —
•
Expires: 2013-02-23
Abstract
Abstract An input speech signal is splitted into a time section and the splitted signal is generated as a speech vector and LPC coefficient sets are developed by linear prediction analysis for every time section of the speech vector. The speech vector is weighted based on the developed LPC coefficient sets, then a plurality of the weighted speech vectors are connected and the connected speech vector having a predetermined frame length is generated. An excitation codevector whose weighted synthesized signal is the most similar to the weighted speech vector is determined among from a plurality of excitation vectors each having the frame length which are previously stored as a sound source. A plurality of adaptive codevectors each having the frame length and obtained by cutting out a sound source signal produced from the determined excitation vectors at predetermined timing points are stored in an adaptive codebook (145). An adaptive codevector whose weighted synthesized signal is the most similar to the weighted speech vector is determined among from the plurality of adaptive codevectors.
Inventors
- 👤 Masahiro C/O Nec Corporation Serizawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 01:34
CPC Classifications
G; G10; G10L; G10L19/00; G10L19/04; G10L19/08; G10L19/12
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
193 words
A speech coding apparatus comprising: a first means for splitting an input speech signal into a time section and generating the splitted signal as a speech vector; a second means for developing LPC coefficient sets by linear prediction analysis for every time section of the speech vector; a third means for weighting said speech vector based on the developed LPC coefficient set; a fourth means for connecting a plurality of the weighted speech vectors and generating connected speech vector having a predetermined frame length; a fifth means storing a plurality of excitation vectors each having said frame length; a sixth means for determining an excitation codevector whose weighted synthesized signal is the most similar to said weighted speech vector among from said plurality of sound source vectors; a seventh means storing a plurality of adaptive codevectors each having said frame length and obtained by cutting out a sound source signal produced from the determined excitation vectors by said sixth means at predetermined timing points; and an eighth means for determining an adaptive codevector whose weighted synthesized signal is the most similar to said weighted speech vector among from said plurality of adaptive codevectors.
Claim 2
Dependent Claim
23 words
A speech coding apparatus as set forth in claim 1, further comprising means for developing weighting coefficient sets used in said third means.
Claim 3
Dependent Claim
34 words
A speech coding apparatus as set forth in claim 1 or 2, wherein said excitation codevector whose weighted synthesized signal is the most similar is determined on the basis of least square error method.
Claim 4
Dependent Claim
226 words
A speech coding apparatus comprising: a first means for splitting an input speech signal into a time section and generating the splitted signal as a speech vector; a second means for developing LPC coefficient sets by linear prediction analysis for a predetermined time period longer than said time section; a third means for developing LPC coefficient sets for said time section by interpolation of said LPC coefficient sets for said predetermined time period; a fourth means for weighting said speech vector based on the developed LPC coefficient set for said time section; a fifth means for connecting a plurality of the weighted speech vectors and generating connected speech vector having a predetermined frame length; a sixth means storing a plurality of excitation vectors each having said frame length; a seventh means for determining an excitation codevector whose weighted synthesized signal is the most similar to said weighted speech vector among from said plurality of excitation vectors as an excitation codevector; an eighth means storing a plurality of adaptive codevectors each having said frame length and obtained by cutting out a sound source signal produced from the determined excitation codevectors by said seventh means at predetermined timing points; and a ninth means for determining an adaptive codevector whose weighted synthesized signal is the most similar to said weighted speech vector among from said plurality of adaptive codevectors.
Claim 5
Dependent Claim
96 words
A speech coding apparatus comprising: means for splitting an input speech signal into a time section and generating the splitted signal as a speech vector; means for developing LPC coefficients by linear prediction analysis for every time section of the speech vector; means for weighting said speech vector based on the developed LPC coefficient set; means for connecting a plurality of the weighted speech vectors and generating connected speech vector having a predetermined frame length; means for developing pitch information from said connected vector; and means for developing sound source information from said connected excitation vectors.
Claim 6
Dependent Claim
122 words
A speech coding apparatus comprising: means for splitting an input speech signal into a time section and generating the splitted signal as a speech vector; means for developing LPC coefficient set by linear prediction analysis for a predetermined frame longer than said time section; means for developing LPC coefficient set for said time section by interpolation of said LPC coefficient sets for said frame; means for weighting said speech vector based on the developed LPC coefficient sets for said time section; means for connecting a plurality of the weighted speech vectors and generating connected speech vector having a predetermined frame length; means for developing pitch information from said connected vectors; and means for developing sound source information from said connected excitation vectors.
Claim 7
Dependent Claim
23 words
A speech coding method to be carried out by the speech coding apparatus as set forth in any of claims 1 to 6.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.