Coding in a wide area positioning system (WAPS)
US8917209B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 28, 2012 |
| Grant date | Dec 23, 2014 |
| Priority date | — |
| Expiry date | May 20, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/709
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Embodiments describe determining position by selecting a set of digital pseudorandom sequences. The magnitudes of the cross-correlation between any two sequences of the chosen set are below a specified threshold. A subset of digital pseudorandom sequences are selected from the set such that the magnitudes of the autocorrelation function of each member of the subset, within a specified region adjacent to the peak of the autocorrelation function, are equal to or less than a prescribed value. Each transmitter transmits a positioning signal, and at least a portion of the positioning signal is modulated with at least one member of the subset. At least two transmitters of the plurality of transmitters modulate respective positioning signals with different members of the subset of digital pseudorandom sequences.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.