Balancing amplitude and phase
US6377620B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 19, 1999 |
| Grant date | Apr 23, 2002 |
| Priority date | — |
| Expiry date | Jan 19, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2027/0024
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
The present invention balances the amplitude and phase of a received QPSK signal that may have been corrupted during transmission. The system determines the amplitude of the I and Q symbols of a received signal, compares them, and applies a correction to one or both channels to correct for amplitude imbalance. For phase imbalance, the system calculates the cross-correlation of the I and Q symbols which should average to zero. A correction factor is derived from the cross-correlation and applied to both channels, returning the phase cross-correlation to zero. The output from the system is a signal corrected in both amplitude and phase.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.