Receiver signal processing system for cap signals
US5930309A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 27, 1997 |
| Grant date | Jul 27, 1999 |
| Priority date | — |
| Expiry date | Feb 27, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/4921
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A CAP signal is processed by a QAM demodulator network. The QAM network causes the CAP signal to rotate about its center frequency, which rotation is removed prior to conveying the CAP signal to utilization networks. In an analog implementation, the CAP signal is frequency upconverted to be centered at Fad/4 so that the QAM processor can use the usual 1, 0, -1, 0 demodulation sequence to bring the CAP signal to baseband. Alternatively, using digital techniques, frequency upconverting is not needed and the 1, 0, -1, 0 demodulation sequence is replaced with a Numerically Controlled Oscillator and full multiplier to allow the QAM processor the bring the CAP signal to baseband.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.