Apparatus for supporting a variety of transmission rates in spread spectrum CDMA system
US6249517A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 13, 1998 |
| Grant date | Jun 19, 2001 |
| Priority date | — |
| Expiry date | Mar 13, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04J13/0022
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An apparatus for spreading the information signals in a CDMA (Code Division Multiple Access) system supporting various information rates, and more particularly, to an apparatus for selecting a channel-separating and PN (Pseudo-random Noise) spreading method according to the rate of the symbol to spread. One channel-separating and/or PN spreading method is selected from two different spreading methods according to a condition among the symbol rate, the length of the orthogonal code, and the chip rate. One spreading method is to use an orthogonal code and the long PN code with a fixed time offset as the channel-separating and the PN spreading code, respectively. The other is to use the long code with different time offset for each channel as the channel-separating and/or PN spreading code. The spreading method gives lots of flexibility in system design and also reduces the multiple access interference among channels with a certain rate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.