Frequency envelope detection method for signal analysis
US7634387B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 2, 2006 |
| Grant date | Dec 15, 2009 |
| Priority date | — |
| Expiry date | Jan 19, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/00
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A signal which varies over time is monitored to determine an alarm condition, where the sample stream of digital values from an A/D converter is divided in to equal length pieces and a Fourier Transform (FT) algorithm is used to transform each piece of the stream into a three dimensional dataset including frequency domain amplitude, frequency and time. A Frequency Envelope is calculated by taking the maxima over the time dimension for a period of time, leaving a two dimensional frequency domain amplitude vs frequency dataset which is compared with new data arriving to determine the alarm condition for each element of the Frequency Envelope either by applying a constant delta additively or multiplicatively or by using a “leaky bucket” algorithm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.