Correction of code drift in a non-coherent memory
US6643678B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 26, 2002 |
| Grant date | Nov 4, 2003 |
| Priority date | — |
| Expiry date | Jul 26, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F7/4818
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus and method allow receivers to quickly acquire a pseudorandom noise signal. A receiver can include a Doppler correction circuit, which permits correlation data with frequency shift in the code to be non-coherently integrated among relatively fewer addresses or tap positions in memory. One receiver includes a Doppler offset generator that can advantageously offset a time index used to address a tap position in a non-coherent memory to compensate for code drift in a code with a frequency offset. The amount of offset is computed by accumulating clock cycles of a clock signal that is related to the frequency offset computed by the DFT or FFT frequency bin. The offset aligns a correlation peak in the received code such that the correlation peak can be accumulated in relatively fewer tap positions or addresses.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.