Rapid-update adaptive channel-equalization filtering for digital radio receivers, such as HDTV receivers
US5648987A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 24, 1994 |
| Grant date | Jul 15, 1997 |
| Priority date | — |
| Expiry date | Mar 24, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L7/08
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In response to a received carrier wave modulated in accordance with a digital signal, a digital radio receiver recovers in digital form a modulating signal that is at times subject to undesirable amounts of multipath distortion. This recovered modulating signal is applied as respective input signals to first and second finite-impulse-response (FIR) filters, each of an N-tap type, the taps of which are adaptively weighted. The first FIR filter responds to the modulating signal to supply an output signal in which multipath distortion is suppressed. The second FIR filter responds to the modulating signal to generate corrections for the tap weights of the first FIR filter, which corrections are generated more rapidly than can be done with a microprocessor of the type commonly known as a "digital signal processor" or "DSP". A digital comparator compares samples of the first FIR filter response to corresponding samples of an ideal response, thereby to generate updated tap weights for the second FIR filter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.