Method for compensating filtering delays in a spread-spectrum receiver
US5940435A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 13, 1998 |
| Grant date | Aug 17, 1999 |
| Priority date | — |
| Expiry date | May 13, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L7/0334
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method for configuring the receiver with an IF delay value that indicates the timing of symbol transitions in a received signal processed by the receiver. The receiver recovers a timing that has the same period as the symbol period, but which is out of phase with the received symbols. The received symbols are members of a constellation with elements that have purely I or purely Q components. A symbol-quality signal is generated by constructing the quantity .vertline..vertline.I.vertline.-.vertline.Q.vertline..vertline.. This quantity is a maximum when the detected symbols are aligned with the expected points in the symbol constellation, and decreases if the detected symbols are rotated away from these constellation points. The method determines an optimal delay value by which the symbol clock should be shifted from the recovered timing by using the symbol-quality signal to evaluate test delays and to successively refine them until the optimal delay value is found.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.