Sampling frequency converter by linear interpolation
US5451944A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 28, 1993 |
| Grant date | Sep 19, 1995 |
| Priority date | — |
| Expiry date | Dec 28, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H17/0657
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A data conversion apparatus for a facsimile system converts a first digital data composed of a sequence of primary values sampled at a first frequency, into a second digital data composed of a sequence of secondary values sampled at a second frequency different from the first frequency. The apparatus is provided with a sampling frequency conversion unit operative before and after every sampling point timed by the second frequency for sampling a pair of preceding and succeeding primary values and for counting respective time differences from the sampling point to the preceding and succeeding primary values. The sampling frequency conversion unit further calculates a secondary value at every sampling point by linear interpolation of each pair of the sampled preceding and succeeding primary values according to the counted time differences to thereby produce the second digital data. A gain control unit compensates a level of the second digital data according to a level of the first digital data to thereby shape the second digital data. The second digital data is further compensated for degradation of a frequency characteristic caused by the linear interpolation to thereby further shape…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.