Preamble code structure and detection method and apparatus
US6356607B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 15, 1996 |
| Grant date | Mar 12, 2002 |
| Priority date | — |
| Expiry date | Nov 15, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W88/08
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
In a first embodiment of the invention, a concatenated preamble code is formed by a kronecker product between two subcodes of the same or different lengths. The subcodes have favorable correlation properties and may be Barker codes, minimum peak sidelobe codes, Gold codes, Kasami codes, Bozta<CUSTOM-CHARACTER FILE="US06356607-20020312-P00900.TIF" ALT="custom character" HE="20" WI="20" ID="CUSTOM-CHARACTER-00001"/> codes, or other codes. At the receiver a two-stage processor is used to detect the concatenated preamble code. The two-stage processor comprises a series of two filters, one of which is preferably a mismatched filter. In another aspect of the invention, a repeated codeword preamble is formed from a series of the same repeated short subcode. The short subcode may be an augmented or truncated odd-length code. At the receiver a single matched filter is preferably used to generate a series of spikes separated by the period of the subcode. An alert/confirm detector non-coherently adds together individual correlation spikes and reject false alarms. The alert function measures total correlation energy and adjusts detection thresholds based thereon, while the confirm function ens…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.