Digital data converter
US5155743A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 9, 1992 |
| Grant date | Oct 13, 1992 |
| Priority date | — |
| Expiry date | Jan 9, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M7/304
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A decoder for recovering an analog signal from its digital representation produced by an encoder employing adaptive-delta-modulation first decodes audio bit-stream (17) in the digital domain with digital delta demodulation (15), to a pulse-code-modulation (PCM) format digital signal. Post-processing (35), complementary to encoder processing is performed digitally on the PCM signal. The output from post-processor (35) is up-sampled, and using delta modulation, a noise shaped single-bit highly oversampled output is produced by converter (14). Applying the single-bit output to lowpass filter (11) re-constructs the decoded analog signal, which is audio output (12). By fully exploiting digital signal processing techniques, the decoder can be manufactured at low cost and exceed the performance of existing analog implementations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.