Methods and apparatus for detecting a cellular digital packet data (CDPD) carrier
US5574750A · kind A · utility
25Cited by
35References
11Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 14, 1993 |
| Grant date | Nov 12, 1996 |
| Priority date | — |
| Expiry date | Sep 14, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/18
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Disclosed herein are methods and apparatus for detecting the presence of a CDPD carrier in a channel of a cellular system (although the invention is broadly applicable to detecting a specific kind of carrier associated with an "overlay" system, wherein an "overlay" system is one that shares the frequency allocation of another system on a non-cooperating basis). This specification describes a spectral estimation technique for detection of a CDPD carrier. In addition, this specification describes an MMSE (minimum mean-squared error) method that improves on the spectral estimation method.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.