Method of selecting propagation delays retained for receiving messages transmitted by spread spectrum radio communication
US5818866A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 19, 1996 |
| Grant date | Oct 6, 1998 |
| Priority date | — |
| Expiry date | Jul 19, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/7117
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The signal received in a CDMA system is sampled at a rate greater than the chip rate of the spreading sequences. In order to assign the propagation delays to the arms of a rake receiver, consecutive delays are tested within a time window by evaluating, for each delay tested, an energy of the correlation between the signal received and a reference spreading sequence to which said tested delay is applied. A selection threshold is determined from the largest of the energies evaluated. A first list is compiled containing delays from the window for which the histogram of the evaluated energies exhibits a local maximum greater than the selection threshold, and a second list is compiled containing delays neighboring the delays of the first list. The delays assigned to the arms of the rake receiver are selected initially from the first list and then, if this is insufficient, from the second list.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.