Global navigation satellite system receiver with blanked-PRN code correlation
US6243409A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 15, 1997 |
| Grant date | Jun 5, 2001 |
| Priority date | — |
| Expiry date | Jul 15, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S19/30
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
GNSS receiver includes a subsystem that reduces the adverse effects of multipath signals on punctual and early-minus-late correlation measurements by making the correlation measurements using a "blanked-PRN code." The blanked-PRN code is all zeros except for adjacent positive and negative short pulses that occur at every code bit transition in a locally-generated PRN code. Using the blanked-PRN code, the receiver makes non-zero correlation measurements only near the code bit transitions in the local PRN code. If the local PRN code and the PRN code in the received GNSS satellite signal are closely aligned, the non-zero correlation measurements are made at the times of the bit transitions in the received PRN code. The contributions to the correlation measurements of the multipath signals that do not have bit transitions during the adjacent positive and negative pulses in the blanked-PRN code cancel when the correlation measurements are accumulated--since these multipath signals are constant during the pulse times. The GNSS receiver includes blanked-PRN code logic that produces the blanked-PRN code from the locally-generated PRN code. The blanked-PRN code logic thus produces a code th…
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