Method for automatically searching a frequency range for signal channels in a receiver for digitally modulated signals, and receiver for applying such a method
US6038433A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 1, 1997 |
| Grant date | Mar 14, 2000 |
| Priority date | — |
| Expiry date | Oct 1, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03J1/0091
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A method for automatically searching a frequency range for signal channels in a receiver for digitally modulated signals is described, each channel having a center frequency, a symbol rate, and a modulation type. The method comprises the steps of scanning the frequency range in first frequency steps corresponding with just less than half the minimum expected symbol rate of the channels, measuring the RF level at each frequency step and comparing the measured RF value with a threshold value, and, if the measured RF value is below the threshold value, continuing said scanning and measuring steps until the frequency range is fully scanned, and, if the measured RF value is above the threshold value, assuming the corresponding frequency as an indication of a digitally modulated signal channel and scanning a frequency area in second frequency steps to determine the edge frequencies of the channel, said second frequency steps being much smaller than said first frequency steps, determining the center frequency of the channel from said edge frequencies, and continuing said scanning and measuring steps for further signal channels until the frequency range is fully scanned.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.