Method and system for reducing the sampling rate of a signal for use in demodulating high modulation index frequency modulated signals
US6085073A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 2, 1998 |
| Grant date | Jul 4, 2000 |
| Priority date | — |
| Expiry date | Mar 2, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/1525
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method and system for reducing the sampling rate of a signal for use with high modulation index frequency modulated signals reduces the power consumption and processing requirements of the digital signal processing equipment which performs the demodulation. In a preferred embodiment, a high modulation index FM signal is divided into in-phase and quadrature phase components by a downconverter (FIG. 1, 10). These components are sampled by analog to digital converters (20, 21) and input to a delay element (40, 41). The resulting delayed and undelayed samples are conveyed to downsamplers (60-63) where the sampling rate is reduced. The undelayed in-phase and delayed quadrature phase components are multiplied together by a first multiplier (70) while the undelayed quadrature phase and delayed in-phase components are multiplied together by a second multiplier (71). The output of the second multiplier (71) is then subtracted from the output of the first multiplier (70) by a subtractor (80) which outputs baseband audio or data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.