Receiver with improved digital intermediate to base band demodulator
US6690748B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 21, 2001 |
| Grant date | Feb 10, 2004 |
| Priority date | — |
| Expiry date | Feb 26, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M3/40
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A digital IF to base band demodulator (120) includes delta sigma samplers (202, 204) for sampling two channels of an IF signal at a sampling rate that is substantially higher than the Nyquist rate for the IF signal. A first pair of decimation filters (206, 208) decimates and filters the output of the delta sigma samplers (202, 204) but keeps the samples at a rate sufficient to perform digital mixing, cross adding, and pulse shape match filtering. A set of mixers (210, 212, 214, 216) mixers the output of the first pair of decimation filters with two phases of a digital representation of an local IF signal. A pair of summers (222, 224) sums, and subtracts outputs of the set of mixers (210, 212, 214, 216) in order to cancel undesired harmonics. A second set of decimation filters (226, 228) decimates and filters the output of the summers (222, 224) applying a filter function that is matched to a pulse shape of a base band signal present in the IF signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.