Multiphase code generator and GNSS receiver

US9255994B2 · kind B2 · utility

Assignee

• QUALCOMM Incorporated · US

Inventor

• Philip John Young · Wrexham, GB

Key dates

• Filing date: Oct 9, 2008
• Grant date: Feb 9, 2016
• Expiry date: Oct 16, 2030

Classification

• Technology area (CPC G): Physics
• CPC primary: G01S19/37
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A code generator, for providing a PRN sequence in a GNSS receiver, has the capability to store an internal status at any given point of the generated sequence. The stored status can be reloaded in the generator, upon an external command, or after a given number of generation cycles, thus slewing the phase of the generated PRN sequence to the value corresponding to the stored status. A parallel-correlation GNSS receiver includes one or more slewable code generators, for successively generating local replicas of GNSS PRN sequences, having different code phases, corresponding to a plurality of candidate signals of different code and Doppler shifts. Each time the code generator must switch from one candidate to a second, it is preemptively controlled or programmed, while generating the code for the first candidate, to store the internal status at the phase point almost aligned with the start of the PRN sequence for the second candidate. When the correlation engine switches from the first candidate to the second one, the stored status is loaded in the code generator, and the small misalignment between the code generator and the desired sequence is corrected, thus setting it at the neede…