Digital receive filter for communications systems
US5757683A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 30, 1996 |
| Grant date | May 26, 1998 |
| Priority date | — |
| Expiry date | May 30, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H17/0664
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A digital receive filter comprises first and second filter parts with a down sampler between them. Each filter part is formed by a plurality of cascaded filter stages each comprising a second order finite impulse response digital filter having symmetrical coefficients which in most cases are integer powers of two, and in other cases are zero or a sum of integer powers of two. The filter stages are implemented by delay units and add units with shifting of bits at the inputs of the add units to implement the coefficients, whereby multipliers are avoided. A described receive filter has two filter stages in the first part, a down sampling factor of two, and seven filter stages in the second part, with scaling factors and ordering of the filter stages to facilitate filtering and minimize noise.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.