Multi-rate implementation without high-pass filter
US8539012B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 13, 2011 |
| Grant date | Sep 17, 2013 |
| Priority date | — |
| Expiry date | Apr 22, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H17/0283
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A filtering method approximates a target Finite Impulse Response (FIR) (or transversal) filter and reduces computational requirements by eliminating high pass filtering required by known multi-rate filters. An input signal is copied into two identical signals and processed in parallel by a full-rate path, and by a reduced-rate path. Parallel filters are computed and applied in each path, the reduced-rate signal is up-sampled, and the two signals summed. The high pass filter required by known multi-rate filters is eliminated and the low pass filter in the prior art is implicit in a down sampling. Linear phase FIR filters are used for down and up sampling, resulting in constant group delay. Added benefits include the option of zero added latency through the filtering and the constant group delay added to the target FIR. The user may choose criteria such as minimum resolution in each band.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.