Vocoder systems providing wave form analysis and synthesis using fourier transform representative signals
US4064363A · kind A · utility
7Cited by
5References
21Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | May 24, 1976 |
| Grant date | Dec 20, 1977 |
| Priority date | — |
| Expiry date | May 24, 1996 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L19/02
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A voice-excited vocoder analyzer divides the audio input signals into a baseband and upper band by deriving Fourier transform coefficients and transmitting the coefficients in a time-multiplex frame. The coefficients (a.sub.n and b.sub.n) are derived in two paths, each path multiplying the input signal by a stepped-frequency local source, (one sine, one cosine), the product feeding a recirculating shift register. The vocoder synthesizer effectively performs the same operations in reverse.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.