Spreading code selection process for equalization in CDMA communications systems
US6680902B1 · kind B1 · utility
46Cited by
5References
10Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jan 20, 2000 |
| Grant date | Jan 20, 2004 |
| Priority date | — |
| Expiry date | Jan 20, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/71052
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The disclosure relates to wireless communications such as cdma systems where variable orthogonal spreading factors are employed. Code words are selected from a representation known as the orthogonal variable spreading factor (OVSF) tree, which allows code words of different length to be mixed yet remain orthogonal. The present invention provides a system whereby a subset of codes are employed whereby the bit rate can be reduced. This is of particular advantage under poor propagation conditions. Mutual interference between users is reduced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.