Reduced complexity fast hadamard transform
US7003536B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 15, 2002 |
| Grant date | Feb 21, 2006 |
| Priority date | — |
| Expiry date | Jul 8, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F17/145
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for performing a radix-4 fast Hadamard transform (FHT) with reduced complexity and for directly determining the maximum output of a fast Hadamard transform using either a radix-4 transform or radix-2 transform without actually generating the outputs. The radix-4 fast Hadamard transform is implemented using only seven operations. To find the maximum value of the output of a fast Hadamard transform and its corresponding index, the N−1 stages of a conventional N stage fast Hadamard transform are computed while a find-maximum stage is inserted in place of the Nth stage. The invention also provides a methodology for constructing fast Hadamard transforms of the form H2using radix-4 FHTs and permuting the results to achieve the correct outputs.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.