Apparatus and method for detecting a signal in a communications system
US5553081A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 8, 1994 |
| Grant date | Sep 3, 1996 |
| Priority date | — |
| Expiry date | Apr 8, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B2203/5408
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
In a communications system, an apparatus and method for detecting a valid signal from noise. An adaptive threshold is used to qualify a received signal. The adaptive threshold is set according to the number of false detects occurring within a given time interval. The number of false detects is initially determined by a quick qualification process. This initial number is subsequently adjusted by a more accurate qualification process. The transmitted signal is modulated with a particular pattern. Upon receiving the signal, it is demodulated to retrieve that pattern. The demodulated pattern is correlated against multiple reference patterns and combined to provide a measure of peak correlation that is independent of pattern phase. Furthermore, a tone detector is used to distinguish valid signals from interfering tones. Two different types of detection methods are performed in parallel. One is based on the energy of the received signal, whereas the other is based on the correlation of the received signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.