Code-division multiple-access system with improved utilization of upstream and downstream channels
US5533012A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 9, 1995 |
| Grant date | Jul 2, 1996 |
| Priority date | — |
| Expiry date | Mar 9, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/71072
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A code-division multiple-access system has a downstream channel for transmission from a base station to a number of mobile stations, and an upstream channel for transmission from the mobile stations to the base station. On the downstream channel, each mobile station's spreading code is divided into two parts, which modulate data transmitted on in-phase and quadrature carriers, respectively, thereby enabling the length of the spreading code to be doubled without increasing the chip rate. On the upstream channel, as soon as a symbol is received from one mobile station, it is despread to estimate its value, then respread and canceled as interference with respect to the other mobile stations, these processes being iterated in a cyclic order of the mobile stations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.