Additive PCM speaker circuit for a time shared conference arrangement
US4835767A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 2, 1987 |
| Grant date | May 30, 1989 |
| Priority date | — |
| Expiry date | Nov 2, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M3/561
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A time shared multiport conference arrangement includes an additive PCM speaker circuit. The additive PCM speaker circuit eliminates the need for loudest speaker detection and the last speaker memory of conventional conferencing arrangements. The additive PCM speaker circuitry operates in an on-line, real time environment to allow rapid summing of speakers' PCM voice samples. Since the PCM voice samples are logarithmic in nature, they are not directly combinable. The additive PCM speaker circuitry provides a storage medium which is preprogrammed with resultant values. These resultant values each correspond to a PCM addition of the values of two input speaker's PCM voice samples. The additive PCM speaker circuit simplifies the complex processing logic usually associated with loudest speaker detection systems and thereby improves the real time operation of the conferencing arrangement.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.