Code-division multiple-access demodulator with improved interference cancelation
US5394434A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 26, 1993 |
| Grant date | Feb 28, 1995 |
| Priority date | — |
| Expiry date | Oct 26, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/71075
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A demodulator for code-division multiple-access spread-spectrum communications stores received chip data in a separate memory area for each transmitting station. Each area has a capacity of at least two symbols. When a complete symbol is received from a transmitting station, all chip data stored in the corresponding memory area are correlated with the corresponding spreading code, and estimated symbol values are derived from the correlated values. The correlated or estimated value of the oldest symbol is output as a demodulated value. The difference between each estimated symbol value and the previous estimate for the same symbol is multiplied by the spreading code to generate remaining interference values, which are subtracted from all chip data stored in memory areas for other transmitting stations, thereby updating those data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.