Method and apparatus for multi-phase component downconversion
US5422909A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 30, 1993 |
| Grant date | Jun 6, 1995 |
| Priority date | — |
| Expiry date | Nov 30, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/707
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The present invention provides a downconverter method and apparatus for downconverting a multiphase modulated signal. The downconverter can be implemented in a multi-phase receiver such as a quadrature receiver. An analog-to-digital converter (103) converts an intermediate frequency signal to a digital signal at a sampling rate. A Hilbert transformation filter (104) and a delay element (105) connected in parallel provide respective passband quadrature and in-phase components of the digital signal. A digital translator (107) alters the passband quadrature and in-phase components based on a predetermined pattern to provide a baseband quadrature signal and a baseband in-phase signal. The digital translator (107) can be a pseudorandom sequence demodulator for demodulating a code division multiple access (CDMA) signal. Various types of DC estimation can also be provided in addition to automatic gain control.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.