Method for composing lookup table and searching index thereof
US7945609B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 29, 2006 |
| Grant date | May 17, 2011 |
| Priority date | — |
| Expiry date | Mar 17, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F1/0353
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method for composing a lookup table and searching indexes thereof is provided. The method includes the steps of: a) composing a lookup table using a symmetry of a sine and a cosine function; b) changing and setting a gain of a DCO by reflecting a lookup table size in the DCO; c) transforming an absolute value of a DCO output to an integer value; d) determining a range of the integer value of the DCO output; e) searching indexes of a sine and an cosine function according to the range of the integer value of the DCO output; and f) correcting a sign of a lookup table value corresponding to the searched index of the sine function and a sign of a lookup table value corresponding to the searched index of the cosine function according to the range of integers of the DCO output.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.