Apparatus and method for angle rotation
US7203718B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 30, 2000 |
| Grant date | Apr 10, 2007 |
| Priority date | — |
| Expiry date | Dec 15, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F7/5446
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An angle rotator uses a coarse stage rotation and a fine stage rotation to rotate an input complex signal in the complex plane according to an angle θ. The coarse stage rotation includes a memory device storing pre-computed cosine θM and sine θM values for fast retrieval, where θM is a radian angle that corresponds to a most significant word (MSW) of the input angle θ. The fine stage rotation uses one or more error values that compensate for approximations and quantization errors associated with the coarse stage rotation. The rotator consolidates operations into a small number of reduced-size multipliers, enabling efficient multiplier implementations such as Booth encoding, yielding a smaller and faster overall circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.