Method for transmitting wideband signals via a communication system adapted for narrow-band signal transmission
US6539050B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 25, 1998 |
| Grant date | Mar 25, 2003 |
| Priority date | — |
| Expiry date | Jun 25, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W52/26
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A communication system is used to transmit and receive a plurality of relatively narrow-band signals and wideband signals. The two signal types share a common electromagnetic spectrum by employing spreading gain and maintaining orthogonality between simultaneously transmitted wideband and narrow-band signals. Signal orthogonality is maintained by selectively choosing orthogonal codes and aligning or spacing a wideband carrier frequency with respect to the narrow-band carrier frequencies in accordance with the ratio of the wideband to the narrow-band chip frequencies. A pilot signal is preferably transmitted contemporaneously with the transmission of the first spreaded signal, and a control data signal, associated with a plurality of users on the first bandwidth, is transmitted on a common control channel using a single Walsh code that is shared by a plurality of users in a TDMA protocol. Further, if the length of the message intended for transmission by the wideband transceivers is below a message length threshold, the message can be transmitted using a common access channel shared by the wideband transceivers. Still further, by adapting the data transmission rate, in response to t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.