Sign detection in multi-dimensional signal measurements
US9355509B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 4, 2014 |
| Grant date | May 31, 2016 |
| Priority date | — |
| Expiry date | Dec 4, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG07C2009/00555
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
Systems, methods, circuits and computer-readable mediums are disclosed for sign detection in multi-dimensional signal measurements. In some implementations, orthogonally oriented antennas are configured to generate signals in response to a magnetic field, where the signals correspond to components of magnetic field vectors in space. A circuit is coupled to the antennas and configured to: determine polarities of the signals based on phase measurements between the signals; reduce a possible number of magnetic field vector interpretations based on the determined polarities of the signals; reduce a possible number of angles or angle differences between the magnetic field vectors based on the reduced possible number of magnetic field vector interpretations; compare the reduced possible number of angles or angle differences to predetermined angle or angle differences; and detect a relay attack based on results of the comparing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.