Enhanced QPSK or DQPSK data demodulation for direct sequence spreading (DSS) system waveforms using orthogonal or near-orthogonal spreading sequences
US7593454B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 21, 2005 |
| Grant date | Sep 22, 2009 |
| Priority date | — |
| Expiry date | Feb 4, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2275
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A method of correcting phase error of a phase shift keyed (PSK) signal includes (a) receiving a signal modulated by a spreading sequence; (b) despreading the received signal using a receiver spreading sequence similar to the spreading sequence of step (a); (c) calculating a crosscorrelation profile between the receiver spreading sequence and the received signal; and (d) calculating an autocorrelation profile of the receiver spreading sequence to determine a spreading code property (SCP). The method also includes (e) estimating a timing error in alignment between the autocorrelation and the crosscorrelation profiles; and (f) correcting a phase error of the signal despread in step (c), by using the SCP and the estimated timing error.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.