CDMA communications system using multiple spreading sequences
US7245650B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Mar 7, 2002 |
| Grant date | Jul 17, 2007 |
| Priority date | — |
| Expiry date | Feb 25, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04J13/10
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
This invention provides techniques for a CDMA system having high spectrum efficiency with low transmit power. Each transmitter comprises means of selecting some core-sequences out of multiple sequences to make them convey plural data, means of producing an enveloped selected sequence with such a method as to arrange as guard sequences to a repeated sequence made by repeating each of the selected core-sequences, means of modulating a user specific orthogonal carrier frequency by the enveloped selected sequence to produce a transmit-symbol, and means of transmitting the transmit-symbols. And a receiver comprises means of demodulating a receive-symbol with one of the user specific carrier frequencies to produce a base-band receive-symbol, means of separating respective components corresponding to the sequences selected by the user, by analyzing the base-band receive-symbol with a matrix composed of a channel response vector from the user to the receiver to detect plural data on the components.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.