Method and apparatus for elimination of mirroring in signal processing system
US5188114A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 31, 1990 |
| Grant date | Feb 23, 1993 |
| Priority date | — |
| Expiry date | Oct 31, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S7/5205
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In a technique for suppression of mirroring in a system which utilizes discrete Fourier transformation of an input signal, a correction apparatus adjusts the observed forward velocity spectrum by a first correction function and adjusts the observed reverse velocity spectrum by a second correction function to provide corrected velocity spectra. The first and second correction functions are representative of mismatches between the in-phase and quadrature channels of the signal processor. The correction functions are obtained during a calibration period in which calibration signals are applied to the signal processor. A first calibration signal contains frequencies of only forward velocities, and a second calibration signal conmtains frequencies representative of only reverse velocities. The correction functions are calculated from the spectra that were measured during calibration. In many cases, the first and second correction functions are the same.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.