Method and apparatus for processing an amplitude modulated (AM) signal
US7092465B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 14, 2002 |
| Grant date | Aug 15, 2006 |
| Priority date | — |
| Expiry date | Dec 23, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/1036
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
In order to protect against adjacent channel interference and the effects of weak signal in AM signal processing, pre- and post-AM demodulation filters (36 and 38) may be used where the bandwidth of both is varied in the same manner by a single controlling mechanism (34). In one embodiment, two or more cascaded filters (20, 24 or 22, 26 or 30,32) may be used for the pre- and post-demodulation filters where each of the cascaded filters has a same predetermined order and uses the same set of coefficients. In one embodiment, all cascaded filters are first order IIR filters, which reduces computation complexity. The use of a same set of coefficient for all the cascaded filters results in a same bandwidth for all filters and further reduces computation complexity. In an alternate embodiment, cascaded filters may be used for only one of the pre- and post-demodulator filters.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.