PCM coder and decoder circuit having digital balancing network
US4787080A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Aug 8, 1986 |
| Grant date | Nov 22, 1988 |
| Priority date | — |
| Expiry date | Aug 8, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B3/23
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A PCM coder and decoder circuit for use in a subscriber line interface circuit of a telephone communication system has a digital balancing network for removing any echo signal. The digital balancing network is formed by series-connecting a first balancing circuit having characteristics corresponding to the fixed characteristics of a coder, decoder, etc. and a second balancing circuit having characteristics corresponding to variable characteristics of an external circuit including two-wire transmission line which is connected to the coder and decoder circuit. Thus, a replica of an echo signal is precisely produced, and the circuit configuration is simplified.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.